FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
1. Title of the Invention
LIQUID FUEL DELIVERY AND USAGE SYSTEMS AND METHODS
2. Applicant(s)
Name Nationality Address
KOKO NETWORKS LIMITED Mauritian C/O Glenera Management Services,
Ground Floor, United Docks Business
Park, Kwan Tee Street, Caudan Port
Louis, Mauritius
KOKO NETWORKS LIMITED Kenyan Level 5, Rivaan Center P.O. Box 888
Nairobi, 00606, Kenya
3. Preamble to the description
The following specification particularly describes the invention and the manner in which it is to be performed
2
Field of the Invention
[0001] In embodiments, the technical field of the invention is liquid fuel
cooking apparatuses and systems.
Background
[0002] Cooking is an essential and ubiquitous activity throughout the
world. Cooking methods, and particularly the predominant fuel used for
cooking, vary greatly across regions. In developing countries, solid fuels such
as charcoal, wood, and dung are often the primary source of energy for
everyday cooking activities at the basic family/consumer level. These solid
fuels are dominant primarily because they are readily available in most
environments. Even in environments where they are scarce resources, they
may be the only options available for consumers.
[0003] Solid fuels, however, have substantial drawbacks as cooking fuels,
especially in the urban context. Although wood may be, technically, a
renewable resource, the growing cycle for most trees suitable as fuels is
impractically long. Furthermore, solid fuels suffer from serious problems
pertaining to pollution (both on a small scale within the immediate cooking
environment as well as a larger environmental scale), renewability, usability
(e.g., solid fuel cooking is slow to start and cannot be readily stopped at will),
and environmental damage due to deforestation and the like. Gathering solid
fuels often requires a substantial amount of time that represents lost
productivity for those involved.
[0004] Liquid fuels and pressurized gases are popular for cooking due to
their reliability, availability, and friendliness to the environment. These fuels,
however, are not practical for low income consumers or consumers living in
areas that do not have the necessary fuel production and distribution
infrastructure, or availability of compatible affordable cooking appliances.
[0005] From an environment perspective as well as other perspectives,
solid fuels cooking would ideally be complemented or replaced (where
contextually appropriate) with liquid fuels in order to address some or all of
the above-mentioned drawbacks.
3
Summary of the Invention
[0006] This disclosure provides methods, devices, and systems suitable for
consumer-level cooking with liquid fuels.
[0007] In an aspect, then, is a reusable liquid fuel canister comprising: a
one-piece housing defining an internal volume; an opening on a first end wall
of the housing, the opening providing access to the internal volume; a
shoulder assembly covering the opening and forming a mechanical connection
with the first end wall or a side wall of the housing; and a valve assembly
contacting the shoulder assembly and forming a fluid-tight seal with the
opening, wherein the valve assembly comprises: a dedicated liquid fuel flow
channel, and a dedicated vapor flow channel axially disposed within the liquid
fuel flow channel. In embodiments:
[0008] the valve assembly is moveable between a default first position and
a second position when mated with a docking valve, wherein in the first
position the valve assembly is closed and provides a fluid-tight seal preventing
fluids from entering or exiting the internal volume via the liquid fuel flow
channel or the vapor flow channel, and wherein in the second position the
valve assembly is open and provides for counter-flow of liquid fuel and vapor
via the liquid fuel flow channel and the vapor flow channel, respectively;
[0009] the valve assembly is moveable between a default first position and
a second position when mated with a compatible container, wherein in the
first position the valve assembly is closed and provides a fluid-tight seal
preventing fluids from entering or exiting the internal volume via the liquid or
vapor channels, and wherein in the second position the valve assembly is open
and provides two unrestricted paths for counter-flow of liquid and vapor
between the two mated containers, with no intermixing of fluids or release to
the atmosphere;
[0010] further comprising at least one locking cam disposed within the
shoulder assembly and configured to form a mechanical connection with a
docking groove on a docking valve;
4
[0011] the shoulder assembly comprises a plurality of attachment points to
the housing and is configured to prevent accidental detachment from the
housing;
[0012] the housing comprises a body portion and a neck portion, the neck
portion beginning at the first end wall of the housing and extending along a
portion of the housing, the neck portion having a narrowed diameter
compared with the body portion, the neck portion comprising external
threading and configured to fit within the shoulder assembly;
[0013] the shoulder assembly comprises a plurality of attachment points to
the housing and is configured to prevent a user from tampering with and
detaching the shoulder assembly from the housing;
[0014] the shoulder assembly is configured to couple with a compatible
docking valve to form a fluid-tight seal with the docking valve, wherein the
fluid-tight seal with the docking valve comprises a continuous fuel flow
channel and a continuous vapor flow channel;
[0015] the vapor flow channel comprises a tube extending from the
opening through the internal volume and terminating at a distal end
comprising a spring-loaded push valve;
[0016] the tube of the vapor flow channel comprises a tube that is laterally
movable;
[0017] the tube of the vapor flow channel comprises a tube that is laterally
movable, and wherein the spring-loaded push valve contacts a second end
wall of the housing when the tube of the vapor flow channel is in a fully
inserted position;
[0018] the tube of the vapor flow channel is laterally movable, and wherein
the spring-loaded push valve contacts a second end wall of the housing when
the tube of the vapor flow channel is in a fully inserted position;
[0019] the housing comprises a body portion and a neck portion, the neck
portion beginning at the top wall of the housing and extending along a portion
of the housing, the neck portion having a narrowed diameter compared with
the body portion, the neck portion comprising external threading and
configured to fit within the shoulder assembly;
5
[0020] the shoulder assembly mates to the housing via a tamper-resistant
pressure fitting (“snap-fit”);
[0021] the neck portion of the housing is threaded so as to create a
reliable, fluid-tight seal when the shoulder assembly and valve assembly are
screwed on to housing;
[0022] further comprising a strap attached to the housing or shoulder
assembly, the attachment being rotatable and configured such that the
position of the strap remains fixed while the housing rotates;
[0023] the housing, shoulder assembly, and valve assembly form a fluid
tight container for liquid fuels, wherein access to the internal volume by a
liquid fuel is enabled by docking the valve assembly to a docking valve;
[0024] a docking valve on a stove is configured to receive and form a
mechanical connection with the shoulder assembly, and wherein the docking
valve and valve assembly are configured such that, when the docking valve
mates with the shoulder assembly, the tube of the vapour flow channel is
moved laterally such that: the spring-loaded push valve contacts a second end
wall of the housing, thereby opening a vapour channel in the spring loaded
push valve; and a fluid flow channel in the valve assembly is opened, allowing
fluid fuel to flow through the valve assembly and into or out of the internal
volume of the housing;
[0025] the shoulder assembly screws onto a threaded neck portion of the
housing to form a fluid tight seal there between; and
[0026] further comprising an NFC chip attached to the housing, the
shoulder assembly, or the valve assembly, wherein the NFC chip is configured
to uniquely identify the liquid fuel canister to an NFC chip reader device;
[0027] In an aspect is a method of using the liquid fuel canister as above,
the method comprising: mating the valve assembly with a docking valve on a
liquid fuel stove so as to form a fluid-tight seal there between, and such that
liquid fuel is gravity transferred into a stove tank in the liquid fuel stove. In
embodiments:
[0028] the transfer of liquid fuel from the canister to the stove tank occurs
without fuel or vapour leakage into the surrounding environment.
6
[0029] In an aspect is a method of refilling the liquid fuel canister as above,
the method comprising: mating the valve assembly with a docking valve on a
(bulk) liquid fuel refuelling station so as to form a fluid-tight seal there
between, and such that liquid fuel is gravity transferred into the internal
volume from a supply tank in the liquid fuel refuelling station. In
embodiments:
[0030] the transfer of liquid fuel from the supply tank to the internal
volume of the canister occurs without fuel or vapour leakage into the
surrounding environment.
[0031] In aspect is a liquid fuel stove comprising the liquid fuel canister as
above in removable fluid communication with a liquid fuel burner element.
[0032] In an aspect is a liquid fuel stove comprising: a liquid fuel burner
element, the liquid fuel burner element comprising a combustion chamber in
communication with a burner fuel reservoir; a stove tank in fluid
communication with the burner fuel reservoir via a fuel supply tube, wherein
a proximal end of the fuel supply tube forms a fluid-tight seal with the stove
tank, and a distal end of the fuel supply tube forms a fluid-tight seal with the
burner fuel reservoir; a docking valve configured to form a reversible fluidtight
docking seal with a removable fuel canister such that fuel can flow into
the stove tank from the removable fuel canister.
[0033] In an aspect is a liquid fuel stove comprising: a liquid fuel burner
element, the liquid fuel burner element comprising a combustion chamber in
communication with a burner fuel reservoir; a manifold in fluid
communication with the burner fuel reservoir via a fuel supply tube, wherein
a distal end of the fuel supply tube forms a fluid-tight seal with the burner fuel
reservoir; a docking valve configured to form a reversible fluid-tight docking
seal with a removable fuel canister such that fuel can flow into the manifold
from the removable fuel canister. In embodiments:
[0034] the combustion chamber is tapered and configured to direct a flame
to the centre of the liquid fuel burner element;
[0035] further comprising a removable fuel canister, the removable fuel
canister comprising a valve assembly configured to form a fluid-tight seal with
7
the docking valve such that the removable fuel canister is in fluid
communication with the stove tank via the fuel supply tube;
[0036] the fuel supply tube further comprises a T-junction and a second
distal end forming a fluid-tight seal with a second burner fuel reservoir of a
second liquid fuel burner element;
[0037] the stove tank and burner fuel reservoir are permanently fixed
inside a housing, and wherein the docking valve is disposed on a top surface of
the housing;
[0038] the housing comprises an opening in a side panel that allows
sideways access to an ignition position located between the burner fuel
reservoir and the combustion chamber;
[0039] the docking valve comprising a docking groove configured to form a
mechanical connection with at least one locking cam disposed within the
shoulder assembly of the removable fuel canister;
[0040] the docking valve is configured to mate with a shoulder assembly of
a canister, wherein in the process of mating, the valve assembly in the
shoulder assembly is laterally moved to an open position thereby forming an
open fluid flow channel through the valve assembly;
[0041] further comprising a float valve disposed within the docking valve,
the float valve configured to move from an open position to a closed position
when the stove tank is full of liquid fuel, wherein when the float valve is in the
closed position liquid fuel is prevented from entering the stove tank from a
removable fuel canister;
[0042] further comprising a shutter disposed between the burner fuel
reservoir and the combustion chamber and operable to regulate a flame at the
liquid fuel burner element, wherein the shutter is configured to ensure the
flame is centrally located above the burner fuel reservoir regardless of a flame
level setting or a regulator knob position, wherein such centrally located flame
is effective to evenly heat a pot placed on the burner and to enable a stable
low simmer of any food item or liquid in the pot; and
[0043] further comprising a housing, and further comprising a lift valve
disposed in the housing, the lift valve movable between an open position
when the stove is positioned on a flat planar surface and a closed position
8
when the stove is not positioned on a flat surface, wherein in the closed
position the lift valve restricts fuel flow through the fuel supply tube and in
the open position the lift valve does not restrict fuel flow through the fuel
supply tube.
[0044] In an aspect is a method of using the liquid fuel stove as above, the
method comprising docking a standalone reusable fuel canister in the docking
valve such that fuel can flow from the canister to the stove tank, and igniting
liquid fuel at the liquid fuel burner element.
[0045] In an aspect is a liquid fuel dispenser unit comprising: a supply fuel
tank; an electronic regulator configured to control dispensing of fuel from the
supply fuel tank, wherein the electronic regulator is configured to be in
electrical communication with a server via a distributed network; and a
docking valve in fluid communication with the supply fuel tank, the docking
valve configured to form a fluid-tight seal with a valve assembly of a reusable
liquid fuel canister and to allow gravity-fed transfer of fuel from the supply
tank to the reusable liquid fuel canister, wherein the fluid-tight seal comprises
a fluid flow channel and a vapor flow channel. In embodiments:
[0046] the docking valve is further configured to allow reverse flow of
vapor from the empty fuel canister to the supply tank;
[0047] the electronic regulator is operatively connected to a valve
controlling fuel flow through an exit port of the supply fuel tank;
[0048] controlling dispensing of fuel further comprises measuring
dispensing of the fuel;
[0049] further comprising an NFC chip reader disposed proximal to the
docking valve and configured to read a unique identifier from an NFC chip
disposed on a reusable liquid fuel canister when the reusable liquid fuel
canister forms a fluid-tight seal with the docking valve;
[0050] the regulator is configured to control fuel dispensing from the
supply tank to the liquid fuel canister based on a user input or a signal
received from a server;
[0051] the regulator is configured to control fuel dispensing based on
input from a user and verification from a server of the user’s remaining credit
9
balance, which balance may be topped up through existing mobile or agentbased
digital payment systems;
[0052] further comprising an interactive user display, and wherein the
interactive user display is configured to receive input from a user and to
display output received from the server;
[0053] the user display is further configured to display an output selected
from fuel balance, transaction history, training material, promotional material,
and purchase of various products and services; and
[0054] further comprising a sensor configured to detect a liquid fuel level
in the supply fuel tank, and wherein the fuel dispenser unit is configured to
send a refueling request to a server via a distributed network when the liquid
fuel level passes below a predetermined threshold.
[0055] In an aspect is a method of operating the liquid fuel dispenser unit
as above, the method comprising: automatically monitoring a liquid fuel level
in the supply fuel tank, and automatically transmitting an alert to a server to
dispatch a resupply vehicle when the liquid level passes below a configured
threshold.
[0056] In an aspect is a liquid fuel dispensing system comprising the liquid
fuel dispenser unit as above and a server configured to communicate with the
electronic regulator via the distributed network. In embodiments:
[0057] further comprising a user liquid fuel stove, the user liquid fuel stove
comprising a docking valve configured to form a fluid-tight seal with the valve
assembly of the reusable liquid fuel canister;
[0058] further comprising a reusable liquid fuel canister comprising a
valve assembly configured to reversibly dock to the docking valve of the liquid
fuel dispensing system and further configured to reversibly dock to a docking
valve of a user liquid fuel stove;
[0059] further comprising a server configured to communicate with the
electronic regulator via the distributed network, wherein the server maintains
a registry of unique identifiers corresponding to a plurality of reusable liquid
fuel canisters, each reusable liquid fuel canister comprising a valve assembly
configured to form a fluid-tight seal with the docking valve;
10
[0060] comprising an NFC chip reader proximal to the docking valve,
wherein: the NFC chip reader is configured to read a unique identifier code
from an NFC chip in a liquid fuel canister upon docking of the liquid fuel
canister to the docking valve; the liquid fuel dispenser unit is configured to
communicate the unique code to a server via a distributed network; the server
is configured to recognize the unique code and associate the unique code with
a stored user account; and the liquid fuel dispenser is further configured to
receive an instruction from the server via the distributed network, the
instruction based on a status of the user account; and
[0061] further comprising a reusable liquid fuel canister comprising a
valve assembly, wherein the valve assembly is configured to form a fluid-tight
seal with a docking valve of a stove and with the docking valve of the liquid
fuel dispenser unit.
[0062] In an aspect is a system for controlled dispensing of a liquid fuel,
the system comprising a processor coupled to a memory, the memory
comprising machine-readable instructions configured to cause the processor
to: receive a request from a liquid fuel dispenser unit, the request comprising
a unique identifier corresponding to a first liquid fuel canister and requested
fuel refill amount; query a database comprising a plurality of unique
identifiers corresponding to a plurality of liquid fuel canisters; identify, from
the database, a customer account record corresponding to the unique
identifier of the first liquid fuel canister, the customer account record
comprising an account balance; generate a message, the message configured
to cause the liquid fuel dispenser unit to initiate a fueling operation and
dispense an amount of fuel based in part on the account balance and in part on
the requested fuel refill amount; transmit the message, via a distributed
network, to a recipient.
[0063] These and other aspects of the invention will be apparent to one of
skill in the art from the description provided herein, including the examples
and claims.
Brief Description of the Drawings
11
[0064] FIG. 1a shows a liquid fuel burner element according to an aspect of
the disclosure, with a cylindrical combustion chamber.
[0065] FIG. 1b shows a liquid fuel burner element according to an aspect of
the disclosure, with a tapered combustion chamber.
[0066] FIG. 2 shows a reusable liquid fuel canister according to an aspect
of the disclosure.
[0067] FIG. 3 shows a canister docked to a docking valve according to an
aspect of the disclosure.
[0068] FIG. 4 shows a canister undocked from a docking valve according to
an aspect of the disclosure.
[0069] FIG. 5a shows a liquid fuel stove with a stove tank and a liquid fuel
canister docked according to an aspect of the disclosure.
[0070] FIG. 5b shows a liquid fuel stove without a stove tank and with a
liquid fuel canister docked according to an aspect of the disclosure.
[0071] FIG. 6a shows a liquid fuel stove with a stove tank according to an
aspect of the disclosure.
[0072] FIG. 6b shows a liquid fuel stove without a stove tank according to
an aspect of the disclosure.
[0073] FIG. 7 shows a valve assembly including a tube of a vapour flow
channel according to an aspect of the disclosure.
[0074] FIG. 8 shows a top view of a stove (with portions cut away)
according to an aspect of the disclosure.
[0075] FIG. 9 shows the internal features of a liquid fuel dispenser unit
according to an aspect of the disclosure.
[0076] FIG. 10 shows the external features of a liquid fuel dispenser unit
according to an aspect of the disclosure.
Detailed Description of Various Embodiments
[0077] In aspects are devices configured to carry out the methods
described herein. The systems described herein may use devices that
comprise a processor and a memory coupled to the processor, the memory
configured to store program instructions for instructing the processor to carry
12
out the method. Further details are provided herein. It will be appreciated,
however, that certain components of such devices, and further certain steps of
the associated methods, may be omitted from this disclosure for the sake of
brevity. The omitted components and steps, however, are merely those that
are routinely used in the art and would be easily determined and
implemented by those of ordinary skill in the art using nothing more than
routine experimentation, the general state of the art, and the disclosure
herein. Throughout this specification, where hardware is described, it will be
assumed that the devices and methods employing such hardware are suitably
equipped with necessary software (including any firmware) to ensure that the
devices/methods are fit for the described purpose.
[0078] The invention pertains to systems for enabling the use of liquid
fuels for cooking applications by individual users, as well as the related
components of such systems and the methods associated with the use and
maintenance of such systems. The systems and methods are user friendly,
environmentally friendly, flexible, suitable for resource constrained
environments, and robust in view of various anticipated challenges.
[0079] The systems are suitable for enabling the use of liquid fuels for
consumer-level (e.g., small commercial kitchens, individual home use, etc.)
cooking and other domestic energy applications (heaters, space heaters, water
heaters, etc.). In embodiments, the fuel for use in the systems herein is
ethanol, kerosene or appropriate fuel with a dynamic viscosity at room
temperature (25 C) that is equal to or less than 5 centipoise (cP). For
example, the fuel may be diluted ethanol (i.e., ethanol with up to 15% water),
denatured ethanol (i.e., ethanol with an additive such as gasoline, kerosene,
methanol, or denatonium benzoate), methanol, or the like. In embodiments,
the term “liquid” fuel is not meant to include substances with a dynamic
viscosity greater than 50 cP at room temperature.
[0080] The systems herein comprise, in embodiments, central refuelling
stations (which stations are serviced by mobile refuelling vehicles when
necessary), consumer fuel canisters, and specialized consumer stoves. The
fuel canisters are refillable and reusable such that a consumer may refill their
personal canister as often as necessary by visiting a refuelling station. The
13
consumer stoves are customized such that they accept and work with the fuel
canisters herein but are otherwise non-operative (unless substantial effort is
made to bypass the aspects of the system that are incorporated to prevent
such non-authorized use). The refuelling stations are customized to accept
and work with the fuel canisters herein, and are further designed to monitor
and prevent unauthorized access to the fuel stored therein. The systems
involve minimal human intervention and are automated with electronic
controls and communication systems for centralized monitoring of multiple
fuel stations by a single monitoring station. The systems incorporate mobile
money payment systems and may be customized to accept other forms of
payment as appropriate for the context. These and other aspects of the system
are described in more detail below and with reference to the attached figures.
[0081] Throughout the disclosure there are references to “fluid tight” seals
and connections. By “fluid tight” is meant that the seal/connection is both
liquid tight and vapour/gas tight. Such connections can be made in any
suitable and effective manner, such as with rubberized O-rings, pressure
fittings, or the like.
[0082] In an aspect is a reusable liquid fuel canister comprising a one-piece
housing defining an internal volume. The internal volume is suitable for
storing a liquid fuel. The housing may be made of any suitable material, for
example a plastic that is compatible with the liquid fuel to be carried within
the internal volume. The housing may be transparent, translucent, or opaque.
For example, the housing may be translucent allowing the user to see a fuel
level within the housing but protecting the fuel from direct light. The housing
may have a transparent or translucent window allowing the user to see a fuel
level within the housing. Other methods allowing the user to determine a fuel
level in the canister are also possible (e.g., color-changing adhesive strips,
etc.).
[0083] In embodiments, the housing is a cuboid with six walls – four side
walls and two end walls. The four side walls may be equal in size such that the
two end walls are squares, although other geometries are possible. The six
walls define an internal volume that may be equal to or less than 10, 7, 5, 3, 2,
14
or 1 litres, or greater than 0.5, 1, 1.5, 2, 3, 4, or 5 litres, or in the range of 0.5-5,
or 1.5-3 litres.
[0084] In an embodiment, the housing is a one-piece housing such that
there are no seams that may be opened without destroying the housing (a
one-piece housing includes housings that are prepared from multiple pieces
that are welded together).
[0085] In embodiments, the canister (i.e., the housing) comprises an
opening on a first end wall of the housing, the opening providing access to the
internal volume. The opening may be circular or otherwise shaped as desired,
and may be of any suitable diameter such as within the range of 1-10 cm. In
embodiments, the opening is flush with the end wall, although in other
embodiments the opening may be raised with respect to the end wall (i.e., the
opening is a neck or other protrusion that is integral with the end wall). In
embodiments the opening comprises a neck portion that may be partially or
fully threaded on the external surface of the neck portion, so as to be
configured to mate (i.e., make a mechanical connection) with a shoulder
component described herein.
[0086] In embodiments the housing comprises a body portion and a neck
portion, the neck portion beginning at the first end wall of the housing (i.e.,
the end with the opening) and extending along a portion of the housing, the
neck portion having a narrowed diameter compared with the body portion,
the neck portion comprising external threading and configured to fit within
the shoulder assembly to form a fluid tight seal therewith. The external
threading may extend along the entire neck portion or a portion thereof.
[0087] The canister comprises a shoulder assembly covering the opening
and forming a mechanical connection with the first end wall or a side wall of
the housing. In embodiments, the shoulder assembly is a component that is
separate from the housing but able to be mated to the housing. In
embodiments, the mating of the shoulder assembly to the housing is such that
it cannot be reversed without specialized tools, or without damaging one or
both components, or without significant force/effort that risks damaging one
or both components. For example, the shoulder assembly comprises a
plurality of attachment points to the housing and is configured to prevent
15
accidental detachment from the housing. For example, the shoulder assembly
and housing form one or more pressure-fitting attachment points and/or one
or more lock-and-key type attachment points. In embodiments the shoulder
assembly mates to the housing via a tamper-resistant pressure fitting (“snapfit”).
In embodiments the shoulder assembly may be multiple separate
components that fit together in a secure manner (e.g., with screw-type mating,
pressure mating, or other forms of mating components) to cover the opening
in the housing. In embodiments, the shoulder assembly comprises four
attachment points, and wherein detachment of the shoulder assembly from
the housing requires simultaneous compression of the four attachment points.
In embodiments, the shoulder assembly is detachable from the housing
provided that detaching the shoulder assembly from the housing requires use
of a specialized tool.
[0088] In embodiments the shoulder assembly (or at least one component
of the shoulder assembly) screws onto a threaded neck portion of the housing
to form a fluid tight seal there between. The portion of the shoulder assembly
that screws onto the neck portion of the housing (which may be referred to
herein as the “valve assembly anchor”) may be a separate component from the
component of the shoulder assembly (which may be referred to herein as the
“canister cap”) that snaps onto the side wall or end wall of the housing, or the
two components may be integral. Where the two components are separate, in
embodiments the valve assembly anchor may be shaped so as to fit within the
canister cap such that it cannot be rotated (and thus unscrewed from the
housing) without removing the canister cap. For example the valve assembly
anchor may have a polyhedral circumference that fits within a complementary
opening in the canister cap.
[0089] In embodiments the canister further comprises a strap attached to
the housing or shoulder assembly, the attachment of the strap being rotatable
and configured such that the position of the strap remains fixed while the
housing rotates. In this way, the canister can be carried over a user’s shoulder
(and freely rotatable for comfort) thereby allowing hands-free transportation.
[0090] In embodiments the canister further comprises at least one locking
cam (e.g., 2, 3, 4, or more than 4 cams) disposed within the shoulder assembly
16
and configured to form a mechanical connection with a docking groove on a
docking valve. For example, the cams may be disposed on the inside
circumference of the canister cap.
[0091] The cams on the canister enable increased leverage during the
docking procedure (via a twisting motion). The shoulder assembly of the
canister has, in embodiments, three cams that fit into corresponding docking
groove on the docking assembly and carefully guide the canister and docking
assembly together with perfect alignment of valves as the canister is twisted
during the docking procedure. This motion is adequate to open/close all four
valves in the valve assembly and docking assembly, thereby allowing crossdirectional
vapour and liquid flow, as described in more detail herein.
[0092] The canister comprises a valve assembly contacting the shoulder
assembly (when the canister is fully assembled) and forming a fluid-tight seal
with the opening. In embodiments, the shoulder assembly, when assembled
onto the housing, presses the valve assembly against the housing (e.g., against
a lip of the neck portion) to form the fluid-tight seal. In embodiments, the
valve assembly may be integral with the shoulder assembly although in other
embodiments they are separate components. The valve assembly is a multipart
component of the canister and ensures that fluid and vapour can enter
and exit the internal volume of the housing only under controlled conditions –
specifically, for example, when the canister is docked to a docking valve as
described herein. The valve assembly may be removable from the canister
and, in embodiments, removal requires first removing the shoulder assembly
as the shoulder assembly holds the valve assembly against the housing.
[0093] The valve assembly comprises a dedicated liquid fuel flow channel.
In embodiments, the fluid flow channel comprises a pathway that is, at least in
part, circular in cross-section and may traverse a plunger and one or more
springs. In embodiments the fluid flow channel is concentrically located
around the vapour flow channel. The fluid flow channel may comprise an
integral component that defines the entire fluid flow channel through the
valve assembly, or the fluid flow channel may be a pathway through the valve
assembly without such a dedicated/integral component (i.e., the pathway may
be defined by the configuration and location of other components).
17
[0094] The valve assembly comprises a dedicated vapor flow channel
axially disposed within the liquid fuel flow channel. In embodiments the
vapour flow channel comprises a tube (e.g., a metal or rigid plastic tube)
extending through the valve assembly. When fully inserted into the housing,
such that the valve assembly forms a fluid-tight seal with a lip of the neck
portion of the housing, the tube of the vapour flow channel extends into the
housing. In embodiments, the tube traverses the entire housing such that it
contacts the second end wall of the housing. In embodiments, the vapour flow
channel is positioned axially at the center of the fuel flow channel.
[0095] In embodiments a portion of the valve assembly is moveable
between a default first position and a second position. In the first position the
fluid flow channel and the vapour flow channel are both closed/sealed such
that no fluid and no vapour can traverse the valve assembly. When the valve
assembly is assembled with the housing, in the first position the valve
assembly is closed and provides a fluid-tight seal preventing fluids from
entering or exiting the internal volume via the liquid fuel flow channel or the
vapor flow channel. A portion of the valve assembly can be moved to a second
position. Such movement can occur when the valve assembly (and shoulder
assembly) is mated with a docking valve as described herein, although other
mechanical forces applied to the valve assembly can cause it to move to the
second position. In embodiments, the portion of the valve assembly that
moves to the second position is the tube of the vapour flow channel and/or a
plunger connected to the tube of the vapour flow channel. In the second
position the valve assembly is open (i.e., both the fluid flow channel and the
vapour flow channel are in an open position) and provides for counter-flow of
liquid fuel and vapor via the liquid fuel flow channel and the vapor flow
channel, respectively. A resistive spring may be positioned within the valve
assembly to ensure that the first position is the default position. At a distal end
of the tube of the vapour flow channel, in embodiments is a spring-loaded
push valve moveable between an open position and a closed position. In the
closed position (which, in embodiments, is the default position), the push
valve is sealed and vapour tight. In the open position, which occurs when the
18
push valve is depressed (e.g., by a wall of the housing or otherwise), the push
valve allows a continuous vapour channel through the valve assembly.
[0096] Thus, in embodiments, the tube of the vapor flow channel is
laterally movable. When the tube of the vapor flow channel is in an inserted
position (i.e., fully inserted into the housing, through the opening, and resting
against a lip of the first end wall comprising the opening), the spring-loaded
push valve contacts the second end wall of the housing. With this
configuration, the default position has the spring-loaded push valve uncompressed
(e.g., simply touching but not pressing against the end wall, or in
embodiments, positioned very close to the end wall such that it has enough
potential lateral movement to be compressed against the end wall) such that
the vapour flow channel remains closed. This default position occurs, for
example, when the canister is assembled with the valve assembly and
shoulder assembly, but when the canister is not docked to a docking valve.
Lateral movement of the tube of the vapour flow channel (e.g., as a result of
docking the canister with a docking valve as described herein, wherein the
docking action causes a plunger dock in the docking valve to push against the
plunger and tube of the valve assembly) causes the tube of the valve assembly
to be inserted further into the internal volume of the housing, thereby
depressing the push valve against the second end wall of the housing and
moving the push valve into an open position, thereby forming an
unconstrained vapour flow channel. Therefore the spring-loaded push valve
enables vapor flow in or out of the canister only when the canister is fully
docked and the tube reaches the fully inserted position.
[0097] In embodiments a docking valve on a stove or a refuelling station
(described in more detail herein) is configured to receive and form a
mechanical connection with the shoulder assembly and simultaneously to
compress a portion of the valve assembly. The portion of the valve assembly
that is compressed comprises the tube and the plunger, and such compression
laterally moves the tube further into the internal volume. Thus, the docking
valve and valve assembly are configured such that, when the docking valve
mates with the shoulder assembly, the tube of the vapour flow channel is
moved laterally such that: the spring-loaded push valve compresses against
19
the second end wall of the housing, thereby opening a vapour channel in the
spring loaded push valve; and the fluid flow channel through the valve
assembly is opened, allowing fluid fuel to flow through the valve assembly and
into or out of the internal volume of the housing.
[0098] In embodiments the tube of the vapor flow channel extends from
the opening of the housing through the internal volume when the valve
assembly is inserted into the housing. The tube of the vapour flow channel
terminates in a spring-loaded push valve at the distal end, and in the plunger
at the proximal end.
[0099] An embodiment of the canister and selected components thereof is
provided in Figures 2, 3, 4, and 5. With reference to those figures, then,
canister 200 comprises (second) end wall 205 and side wall 210. It further
comprises a shoulder assembly that comprises canister cap 225, wherein
canister cap 225 comprises pressure fitting clips 220 that contact side wall
210. Canister cap 225 also comprises a plurality of cams 250. The shoulder
assembly further comprises valve assembly anchor 230, which is threaded
and forms a screw-type connection with neck portion 222 of the housing,
whilst holding the valve assembly (not individually labelled) in place.
[00100] The valve assembly comprises tube 215 defining the vapour flow
channel, and push valve 201 at a distal end of tube 215. Push valve 201 nearly
touches end wall 205 in a default first position, but is closed in that position,
and is open in a second position when compressed against end wall 205. The
proximal end of tube 215 terminates (235) at plunger 240, which comprises
two O-rings (labelled 241 and 242) and is attached to spring 245. Lateral
movement of plunger 240 causes O-rings 241 and 242 to engage and
disengage different surfaces. In Figure 2, for example, valve assembly is shown
in an undocked (and therefore default, closed position) such that O-ring 241 is
pressed against valve assembly anchor 230. This configuration ensures that
there is no open liquid flow channel into the internal volume of the housing.
Furthermore the push valve 201 is in the closed position such that there is no
open vapour flow channel into the internal volume of the housing. The same
(closed and undocked) configuration of the canister and valve assembly is
shown in Figure 4. Sleeve 440, which comprises a plurality of concentrically
20
spaced holes 435 (so as not to impede the liquid flow channel), provides an
anchor to prevent lateral movement of tube 215.
[00101] Figure 3 shows the canister and docking assembly in a docked
configuration, with the fluid flow channel open for bi-directional flow of liquid
and vapour. Plunger 240 has been moved (by force exerted by plunger dock
310) into an open position. O-ring 241 no longer contacts the valve assembly
anchor, and O-ring 242 now contacts plunger dock 310. Spring 315 provides
resistance for plunger dock 310 and also allows a liquid flow channel within
the docking valve to open, i.e., when O-ring 430 is moved downward due to
pressure from plunger 240. Docking valve wall 320 comprises one or more
grooves (not labelled) that fit with one or more cams (not labelled) on the
shoulder assembly. Stove tank 325 also comprises float valve 330. The undocked
configuration is shown in Figure 4. O-ring 430 is pressed against a wall
within the docking valve thereby closing the liquid flow channel.
[00102] As mentioned, the stove tank 325 is optional. Where stove tank 325
is not present (embodiment not shown in the figures), it is replaced with a
manifold that directs fuel to the burner fuel reservoirs. Furthermore
optionally in such embodiments, the burner fuel reservoir has a perorated
inlet supply tube near the top of the reservoir and a return tube at the bottom
of the reservoir. The return tube returns to the manifold and passes a float
valve such that a full reservoir causes closing of the valve and the supply of
fuel to be terminated.
[00103] In embodiments the canister comprises an NFC chip attached to the
housing, the shoulder assembly, or the valve assembly. The NFC chip is
configured to uniquely identify the liquid fuel canister to an NFC chip reader
device. Thus the NFC chip may encode an identification code (e.g., an
alphanumeric code or other code) as well as other optionally encrypted
information such as a registered owner’s identification details, a place and
time of manufacture, a place and time of sale to a user, and the like. Such
information may be immutable, read/writable, or a combination thereof.
[00104] The invention further comprises a liquid fuel stove that is
compatible with the liquid fuel canister described herein. The stove comprises
a housing, which may be made of any suitable material such as metal sheeting.
21
The stove housing is configured as described herein and below. Although a
two-burner configuration is described, it should be appreciated that other
configurations are also within the scope of the invention.
[00105] The stove comprises a docking valve configured to form a
reversible fluid-tight docking seal with the removable fuel canister. The
docking valve is disposed, in embodiments, in a top surface of the stove
housing, such that it is exposed to enable a user to dock a canister to the
docking valve, and is permanently fixed in such a configuration. The docking
valve may be covered by a removable fuel tank cap. Certain other components
of the stove such as the burners are disposed in a top surface of the stove
housing.
[00106] The docking valve receives and mates with the shoulder assembly
and valve assembly of the canister. In embodiments the docking valve
comprises a docking groove configured to form a mechanical connection with
at least one locking cam disposed within the shoulder assembly of the
removable fuel canister.
[00107] The docking valve is configured to mate with a shoulder assembly
of a canister. The docking valve comprises a plunger dock – a spring-loaded
component that can move between a first default (closed) position and a
second (open) position. The plunger dock is axially disposed in the docking
valve and is configured to contact the plunger of the valve assembly when the
canister is mated to the docking assembly. In embodiments the plunger dock
is configured to fit snugly (but with sufficient tolerance to allow for smooth
insertion) within the valve assembly anchor.
[00108] In the process of docking the canister to the docking valve, the valve
assembly (or components thereof, such as the tube and plunger) in the
shoulder assembly makes contact with the plunger dock and is laterally
moved (e.g., by being compressed against the plunger dock component of the
docking assembly) to an open position thereby forming an open fluid flow
channel through the valve assembly. Simultaneously, the process of docking
causes the plunger dock to move laterally to an open position, thereby
forming continuous liquid and vapor flow channels into the stove tank or
manifold below the docking assembly. In this way, a continuous liquid flow
22
channel is formed between the canister and a stove tank or manifold located
immediately below the docking valve. Similarly, a vapour flow channel is
formed allowing vapour to flow from the stove tank or manifold into the
canister, replacing the volume lost when liquid fuel flows out of the canister.
[00109] In embodiments, when the canister is coupled with a compatible
docking valve, then all four valves between them are opened to allow crossdirectional
fluid flow in two channels (one for vapor, one for liquid), while
maintaining an air-tight seal from the atmosphere. Similarly, when the
canister and docking valve are uncoupled then all four valves close
automatically, thereby limiting contact of contained fluid with atmosphere at
any point over repeated cycles of use.
[00110] The stove, then, in embodiments, comprises a stove tank located
immediately below, and in fluid communication with, the docking valve. The
stove tank is permanently fixed in to the stove housing for stability, and can be
of any suitable size and configuration. In embodiments the stove tank has a
low profile and a volume of equal to or less than 5, 4, 3, 2.5, 2, 1.5, 1, or 0.5 L,
or greater than 0.5, 1, 1.5, 2, 2.5, 3, or 4 L, or in the range of 1-5, 0.5-3 or 0.5-2
L. In embodiments the stove tank may be filled with a fibrous or other
absorbent material although in other embodiments the stove tank may lack
any solid filler material.
[00111] In alternative embodiments, the stove may lack a stove tank, and
instead comprise a manifold directly below, and in fluid communication with,
the docking valve. The manifold channels fuel directly into the burner fuel
reservoir(s). In such alternative embodiments, the lift valve is optionally not
present.
[00112] The stove may, in embodiments, comprise a float valve disposed (in
part) within the docking valve (and also disposed, in part, within the stove
tank when present, thereby bridging the two components), the float valve
configured to move from an open position to a closed position when the stove
tank is full of liquid fuel, wherein when the float valve is in the closed position
vapor is prevented from leaving the stove tank and thereby liquid fuel is
prevented from entering the stove tank from a removable fuel canister docked
to the docking valve. Where the stove lacks a stove tank, the float valve may
23
still be present, and may be located within the channel connecting the fuel
burner reservoir with the docking valve or manifold. The float valve will close
when the stove tank or burner fuel reservoirs are full, and a window in the
stove housing can be present to allow the user to observe that the float valve
has closed (and thus that the user should stop filling the stove and remove the
canister).
[00113] The stove comprises a liquid fuel burner element, the liquid fuel
burner element comprising a combustion chamber in communication with a
burner fuel reservoir. The stove may comprise a single burner, two burners,
or more than two burners. Although throughout this disclosure is described a
two-burner stove, such disclosure is merely for the sake of convenience and it
will be appreciated that the same disclosure will apply to single burner stoves
(and stoves with more than two burners) without the need for anything
beyond routine optimization.
[00114] In embodiments, the combustion chamber is a cylindrical channel
positioned above the burner fuel reservoir (e.g., above a hole in the top part of
the burner fuel reservoir, within which hole may be a fibrous material such as
fiberglass or ceramic wool or the like, and through which hole fuel passes on
the way to being ignited in the combustion chamber). The height of the
combustion chamber may vary but is typically in the range of 1-10 cm or 2-8
cm. Above the combustion chamber, in embodiments, is a flame spreader
configured to form a flame suitable for cooking or other purposes. Such
spreading causes the flame to cover a wider area and is suitable for heating
pots, pans, etc.
[00115] Between the combustion chamber and the burner fuel reservoir, in
embodiments, is a shutter that is operated by a flame regulator (knob or
lever) and is operable to regulate a flame at the liquid fuel burner element. In
embodiments, the shutter consists of three petals so that at any regulator
setting, the flame is 3-way symmetrical about the center of the burner. This
affects the flame in two ways: 1) the flame does not get shifted to the side on
medium or low setting, and so an entire pot gets heat evenly distributed
regardless of the flame regulator setting; and 2) when on simmer/low setting,
the flame is very stable and less prone to getting snuffed out by a
24
breeze/draught. More than three petals may be present in the shutter.
Alternatively to the petal-type shutter is a single disc shutter. The disc is
movable between a fully “closed” position (i.e., blocking the combustion
chamber from the fuel reservoir) and a fully “open” position (i.e., not blocking
the combustion chamber). Where a disc-type shutter is used, the burner
assembly may further comprise a tapered combustion chamber that helps to
direct and centre the flame (i.e., so that the flame is not shifted to the side on
medium or low setting). In embodiments the combustion chamber is partially
tapered and partially cylindrical (e.g., the bottom half of the combustion
chamber is tapered and the top half is cylindrical).
[00116] Movement of the shutter, whether the shutter is a disc or a petaltype
shutter, is controlled by movement of the flame regulator. In
embodiments the flame regulator is a knob or dial. Furthermore, in
embodiments, the flame regulator simultaneously operates a fuel cap lock
operable to lock the fuel cap covering the docking valve. This simultaneous
operation can be carried out, for example, via a safety interlocking system
(e.g., a system of appropriate levers to simultaneously engage the shutter and
a cap lock). The burner fuel reservoir, located immediately below the shutter
and combustion chamber, comprises a hole exposing the fuel stored therein,
and in embodiments is filled with a solid but porous and absorbent material
such as ceramic wool or the like (e.g., helping the burner fuel reservoir absorb
fuel, and preventing spillage if the stove is tilted or overturned). The burner
fuel reservoir is generally smaller than the stove tank (when present) and may
be, in embodiments, less than or equal to about 500, 300, 200, 100, or 50 mL,
or greater than 25, 50, 100, 150, 200, or 300 mL, or in the range of 50-500 or
100-300 mL. Where a stove tank is not present, the burner fuel reservoir will
typically be larger, such as in the range of 300-1500, or 750-1250 mL, or equal
to or less than about 1500, 1250, 1100, 1000, or 750 mL, or equal to or greater
than 500, 750, 900, 1000, or 1250 mL.
[00117] Examples of the burner element are shown in Figure 1a and Figure
1b. In the figure, combustion chamber 105 is located below flame spreader
100 but directly above shutter 120. Below shutter 120 is burner fuel reservoir
115. Shutter 120 is controlled with flame regulator 110. In Figure 1a the
25
combustion chamber is cylindrical and the shutter has three petals, whereas
in Figure 1b the combustion chamber is tapered and the shutter is a single
disc.
[00118] The stove tank, when present (or, the manifold when the stove tank
is not present), is in fluid communication with the burner fuel reservoir via a
fuel supply tube, wherein a proximal end of the fuel supply tube forms a fluidtight
seal with the stove tank, and a distal end of the fuel supply tube forms a
fluid-tight seal with the burner fuel reservoir. In embodiments, the fuel supply
tube further comprises a T-junction and a second distal end forming a fluidtight
seal with a second burner fuel reservoir of a second liquid fuel burner
element. In further embodiments, the fuel supply tube comprises an
additional offshoot that leads to a fuel gauge configured to allow a user to see
the amount of fuel in the stove tank. In embodiments the docking valve is
disposed centrally between two burners (thus necessitating a T-junction in
the fuel supply tube) although other configurations are possible. For example,
the docking valve can be located at one end of the stove and the two burners
located at the centre and at the opposite end of the stove, respectively, from
the docking valve. When the stove tank is not present, the manifold is
connected to each burner fuel reservoir via a supply tube.
[00119] In embodiments, the fuel supply tubes enter the burner fuel
reservoir from the bottom of the reservoir, such that gravity is used to force
fuel through the supply tube and up/into the burner fuel reservoirs from the
stove tank. In alternative embodiments, and particular where the stove lacks a
stove tank, the fuel supply tubes enter the burner fuel reservoirs not at the
bottom of the reservoirs but at a relatively small distance below the
combustion chamber of the burner. For example, the burner fuel reservoir
may comprise a top surface that is below the combustion chamber (and
comprises the shutter described herein), and includes a ceramic wool or
similar material. In such an example, a short distance below the top surface of
the fuel reservoir (e.g., between 5-25 mm, or about 5, 10, 15, or 20 mm, or
about 5 mm, or about 10 mm), the fuel supply tube enters the reservoir.
Where it enters the reservoir, it becomes a perforated supply tube (i.e., the
supply tube mates with a perforated supply tube, or in the event that it’s a
26
single monolithic tube, perforations are added to the supply tube once the
tube passes into the reservoir) that is configured to allow fuel to seep out of
the tube and saturate the ceramic wool or other material in the burner fuel
reservoir. Much like a drip irrigation mechanism, the perforated supply tube
section allows fuel to saturate the material at the top of the burner reservoir
and then percolate through the material such that the entire fuel reservoir is
filled. In this way, even a small amount of fuel (e.g., 300 ml or less) added to
the stove via the dock and manifold will be usable. The user is able to
purchase a small amount of fuel, add it to the stove from a canister, and use
the fuel immediately, as the fuel will be available at the top of the burner.
Furthermore, in embodiments, the stove further comprises a return tube at
the bottom of the burner fuel reservoir, which tube is connected back to the
manifold. In such an arrangement, fuel enters the reservoir at the top of the
reservoir (through the perforated supply tube), fills the reservoir, and when it
has saturated the material in the reservoir, flows back through the return tube
to lift a float valve and cut off the supply of fuel to avoid overfilling.
[00120] In embodiments, the burner fuel reservoir is positioned so that fuel
can be gravity fed thereto from the stove tank (or the manifold). To prevent
overflow, however, the stove tank can be positioned such that the top of the
stove tank (when present) is lower than the top of the burner fuel reservoir.
When the stove lacks a stove tank, overflow is only an issue during transfer
from the canister to the burner fuel reservoirs, and in such embodiments
overflow is avoided via the float valve.
[00121] In embodiments, the housing comprises an opening in a side panel
that allows sideways access to an ignition position located between the burner
fuel reservoir and the combustion chamber. By “sideways ignition” is meant
that a match or other flame source can be held horizontally when igniting the
burner. This is distinct from stove/burner designs that require the flame
source to be held at an angle or nearly vertical in order to access an ignition
position and ignite the fuel.
[00122] In embodiments the stove further comprises a lift valve disposed in
the housing, the lift valve movable between an open position when the stove is
positioned on a flat planar surface and a closed position when the stove is not
27
positioned on a flat surface, wherein in the closed position the lift valve
restricts fuel flow through the fuel supply tube and in the open position the lift
valve does not restrict fuel flow through the fuel supply tube. For example the
lift valve can be positioned below the stove tank, and in line with the fuel
supply tube (e.g., at a T-junction or otherwise) and configured to contact a
surface upon which the stove is resting. In embodiments the lift valve can be
operable to open/close the shutter that restricts a flame at the burner, thereby
improving safety of the stove design. In typical embodiments lacking a stove
tank, the lift valve is not necessary and is not present.
[00123] Example embodiments of a stove and components of the stove are
shown in Figures 3, 4, 5a, 5b, 6a, 6b, 8a, and 8b (it is noted that some figures
show cutaway or partial cutaway images with certain components missing to
improve the view). The stove has housing 525, which comprises an opening in
side wall 500 (allowing sideways access of a flame source to the burner). The
burner comprises burner fuel reservoir 505, below which is inlet port 510.
Inlet port 510 is typically in communication with stove tank outlet port 515 by
a fuel supply hose (not shown). Lift valve 520 allows for fuel cut off when the
stove is lifted or tilted. Pot holder 600 is positioned on each burner so as to
provide a convenient stable place to rest a pot and to shield the flame from
light draughts. Cap 605 is placed on the docking valve. A system of levers 820
are in communication with flame regulator 110 – operation of flame regulator
110 causes the levers to shift and open or close a locking mechanism that
prevents or allows cap 605 to be removed for fuelling operations. In Figures
5b, 6b and 8b, no stove tank is present. Also, no lift valve is present.
[00124] The systems herein comprise a liquid fuel dispenser unit, which
dispenser unit is located conveniently for a user to visit and refill a canister as
described herein. For example the dispenser unit can be located in a market or
other shopping centre, a petrol station, or another convenient place. The
location should provide electrical power as well as convenient access to a
refuelling truck. In embodiments, due to the automated maintenance and
monitoring described herein, no human supervision of the dispenser unit is
necessary, although in embodiments the unit may be located where an
attendant is present.
28
[00125] The dispenser unit comprises a housing, which housing is
sufficiently sized to hold all of the other components described for the
dispenser unit, as well as to be relatively insusceptible to theft of the
dispenser unit. The housing may be, for example, made of sheet metal and
having a height in the range 0.5-2.5 m, or 1-2 m, or any other suitable height.
The length and width may be within the range 0.3-1 m or any other suitable
length and width. The dispenser unit comprises a supply fuel tank. The tank
may be of any suitable volume (which may depend on local regulatory
requirements), such as within the range of 100-1000 litres or 100-250 L, or
such as greater than or equal to 50, 100, 150, 200, 300, 400, 500, or 750 L, or
less than 1000, 750, 500, 300, 200, 150, 100, or 50 L, or within the range of
50-250, L, or the like. In embodiments the tank is of steel or compatible plastic
construction and has suitable input and output access points.
[00126] The dispenser unit comprises an electronic regulator connected to
an outlet of the supply fuel tank. In embodiments the electronic regulator is
operatively connected to a valve controlling fuel flow through an exit port of
the supply fuel tank. The electronic regulator may be a component of a
computer (i.e., processor coupled to a memory) or may be remotely controlled
by an off-site computer. In either case, however, the electronic regulator is
coupled to a communications module configured to communicate via a
distributed network (e.g., a cellular network, a WiFi network, a Bluetooth
network, a fixed line network, or the like) with at least one server. The server
comprises a database of user accounts, each user account comprising any of
the following: a user ID, a user passcode, a user history, a user account
balance, and the like. In embodiments the user account corresponds to the ID
that is stored on the NFC chip of a particular canister. In other embodiments
the user account corresponds to a human user, in which case the user account
will identify the canister(s) that belong(s) to the user.
[00127] The electronic regulator is configured to measure and control
dispensing of fuel from the supply fuel tank. The dispensing is monitored such
that a known amount of fuel is supplied from the supply fuel tank and tracked
such that the supply fuel tank can be resupplied when it is empty or nearly
empty. The amount dispensed is determined by user input and/or, where
29
appropriate, a signal from a server based on an amount of credit/money in a
user account (e.g., when the user requests more fuel than can be paid for by
funds/credit in the user account, then the amount dispensed will be less than
the amount requested). In embodiments the electronic regulator is configured
to regulate fuel dispensing from the supply tank to the liquid fuel canister
based on input from the user and verification from the server of their
remaining credit balance. In embodiments, the user account can be topped up
through existing mobile or agent-based digital payments.
[00128] Dispensing of fuel from the supply fuel tank is via a docking valve –
i.e., the dispenser unit comprises a docking valve that is in fluid
communication with the supply fuel tank and is exposed in a location on the
exterior of the dispenser unit and conveniently accessed by the user. The
docking valve is configured to form a fluid-tight seal with a valve assembly of a
reusable liquid fuel canister, wherein the fluid-tight seal comprises a fluid
flow channel and a vapor flow channel. In this way fluid can flow into the
canister while vapour is channelled back to the supply fuel tank, thereby
maintaining a closed system during the transfer (i.e., no venting of vapour to
the atmosphere). In embodiments, no pumps are required for filling a canister
from the supply tank. The supply tank is positioned higher than the docking
valve, thereby allowing gravity-fed transfer of fuel from the supply tank to the
reusable liquid fuel canister.
[00129] The docking assembly of the dispenser unit is positioned on an
exterior surface of the dispenser unit and is configured to receive and mate
with a canister (i.e., a shoulder assembly and valve assembly of a canister).
The docking valve for the dispenser unit is the same as the docking valve for a
stove, thereby ensuring inter-compatibility. In embodiments the liquid fuel
dispenser unit further comprises an NFC chip reader disposed proximal to the
docking valve and configured to read a unique identifier from an NFC chip
disposed on a reusable liquid fuel canister when the reusable liquid fuel
canister is docked to the dispenser unit (i.e., forms a fluid-tight seal with the
docking valve).
[00130] The liquid fuel dispenser unit further comprises a sensor
configured to detect a liquid fuel level in the supply fuel tank. The sensor can
30
be disposed within the tank, on an exterior surface of the tank, or in-line with
an exit port of the tank, as desired or convenient. The fuel dispenser unit is
configured to send a refuelling request to a server via a distributed network
when the liquid fuel level passes below a predetermined threshold, as
determined by the sensor. The sensor can be a separate sensor or can be a
component of the electronic regulator mentioned herein.
[00131] The dispenser unit further comprises an interactive user interface
such as a display. The interactive user display is configured to receive input
from a user and to display output received from the server or otherwise
determined by the system. The user display may be configured to display an
interactive menu-based system that allows the user to purchase fuel, check a
balance or user settings, and carry out other options. The user display may be
configured to display an output selected from fuel balance, transaction
history, training material, promotional material, and purchase of various
products and services, or any combination of such outputs. The user display is
controlled by a control unit that is further in communication with the
electronic regulator and other components of the dispenser unit. The control
unit comprises a processor and a memory with machine-readable instructions
that enable the control unit to manage the operation of the various
components of the dispenser unit. In some embodiments the electronic
regulator may be a software-based component of the control unit, whereas in
other embodiments the two components are separate.
[00132] Filling the supply tank of the dispenser unit requires servicing the
unit by a supply truck or other supply source. The dispenser unit may, in
embodiments, be configured so as to have a refilling conduit/pipe that extends
from the supply tank and dispenser unit to an exterior wall of the facility in
which the dispenser unit is located. In this way, a supply truck can refill the
supply tank without needing direct access to the unit itself, thereby allowing
flexibility in the refilling schedule.
[00133] The dispenser unit may comprise further components such as a
backup power source, anti-tampering sensors, Internet router or other
communications equipment, physical locks, fuel filters, etc., as desired or
necessary. The dispenser unit may comprise a range of additional sensors
31
including a vapor leak sensor, fire sensor, vandalism sensor, etc., each of
which reports back to a server when desired or pre-programed.
[00134] Examples of dispenser units are shown in Figures 9 and 10. In the
figures, housing 920 provides structure to the device. Inside, fuel supply tank
921 has fluid outlet hose 925, which outlet feeds directly to a liquid flow
channel of docking valve 935. The corresponding vapor flow channel of
docking valve 935 is in communication with fuel supply tank 921 via hose
930, thereby ensuring that vapors displaced from a canister during refuelling
are captured and contained within fuel supply tank 921. The dispense unit
further comprises supply inlet 910 which may be in communication with a
hose positioned conveniently for resupply vehicles (as shown, the supply inlet
crosses into an adjacent wall, which may be an external wall at the location).
Alternatively a resupply vehicle may connect directly to inlet 910. The
dispenser unit further has backup power supply 905 and control unit 900. The
dispenser unit further has user interface 1005 and docking valve support
structure 1015, which is conveniently located (low to the ground to enable
gravity-fed fuelling of user canisters) for receiving canister 1010.
[00135] In embodiments, the fuel dispenser comprises a fuel pump
configured to regulate the rate of dispensing of fuel to the canister. In such
embodiments, fuel flow is not purely gravity-based (as is the case where the
fuel dispenser does not have a pump, or where the pump is present but not
operated). The presence of a pump can ensure that canister refilling speed is
consistent regardless of fuel level in the dispenser.
[00136] The dispenser unit, stove, and canister are part of a liquid fuel
dispensing system. The system further comprises a server configured to
communicate with the dispenser unit (i.e., the control unit and/or the
electronic regulator on the dispenser unit) via the distributed network. In
embodiments the server comprises a server configured to communicate with
the electronic regulator (directly or, where a separate control unit is present,
indirectly via the control unit) via the distributed network, wherein the server
maintains a registry of unique identifiers corresponding to a plurality of
reusable liquid fuel canisters, each reusable liquid fuel canister comprising a
valve assembly configured to form a fluid-tight seal with the docking valve. In
32
embodiments the dispenser unit comprises an NFC chip reader proximal to
the docking valve, wherein: the NFC chip reader is configured to read a
unique identifier code from an NFC chip in a liquid fuel canister upon docking
of the liquid fuel canister to the docking valve; the liquid fuel dispenser unit is
configured to communicate the unique code to a server via a distributed
network; the server is configured to recognize the unique code and associate
the unique code with a stored user account; and the liquid fuel dispenser is
further configured to receive an instruction from the server via the distributed
network, the instruction based on a status of the user account.
[00137] The systems and components herein described are suitable for
various methods of use. In an embodiment is a method of using the liquid fuel
canister as described herein, the method comprising: mating the valve
assembly with a docking valve on a liquid fuel stove so as to form a fluid-tight
seal there between, and such that liquid fuel is gravity transferred into a stove
tank or manifold in the liquid fuel stove. As the fuel fills the stove tank, the
float valve rises and, when the stove tank reaches a certain level, the float
valve impedes further transfer of fluid. Simultaneously liquid fuel from the
stove tank is transferred to the burner fuel reservoir(s). The relative positions
(e.g., heights) of the stove tank and burner fuel reservoir(s) can be used to
automatically ensure that the appropriate amount of fuel is transferred at all
time that there is fuel in the stove tank. Alternatively, without a stove tank, the
fuel is transferred to the burner fuel reservoirs via the manifold, and again a
float valve is present to prevent overfilling of the burner fuel reservoirs.
During this process, however, the canister is docked and, in embodiments, the
presence of the canister in the docking valve requires that the shutters
covering the burners are in a closed position – i.e., the stove cannot be lit
while the canister is docked. Upon removal of the canister, the fuel cap can be
replaced and the shutters can be re-opened to allow for operation of the stove.
[00138] The methods further comprise refuelling a canister. This involves
mating the valve assembly of a canister with a docking valve on a liquid fuel
refueling station so as to form a fluid-tight seal there between, and such that
liquid fuel is gravity transferred into the internal volume from a supply tank in
the liquid fuel refueling station. As described herein the amount of fuel
33
transferred can be determined by a server based on user input and credit
available. Throughout the refilling process, the flow rate from the supply tank
can be monitored to ensure it is consistent with the operation. For example if
the flow rate drop significantly the system can shut an outlet valve on the
assumption that the canister has become full.
[00139] The methods involve cooking operations by a user. For example the
methods comprise docking a standalone reusable fuel canister in the docking
valve such that fuel flows from the canister to the stove tank, and igniting
liquid fuel at the liquid fuel burner element. Prior to igniting the fuel the
method further involves removing the canister and opening a shutter at the
burner.
[00140] The methods include operating a liquid fuel dispenser unit. For
example, the methods involve automatically monitoring a liquid fuel level in
the supply fuel tank, and automatically transmitting an alert to a server to
dispatch a resupply vehicle when the liquid level passes below a configured
threshold.
[00141] The methods include notifications to the user as appropriate, such
notifications being sent via messages to a dispenser unit for display on the
user display, or via a cellular network to the user’s mobile number or email
account on record in the user database, or the like. For example, in
embodiments the liquid fuel canister comprises an NFC chip configured to
uniquely identify the liquid fuel canister with a unique identifier, and wherein
the server is configured to store a user account and passcode associated with
the unique identifier of the liquid fuel canister, and wherein the server is
configured to transmit an alert to a user associated with the unique identifier
of the liquid fuel canister based on a status of the user account. The alert can
also be sent to the user if, for example, the canister is reported lost/stolen and
is used again (presumably by an unauthorized user).
[00142] In embodiments is an electronic system for controlled dispensing of
a liquid fuel, the system comprising a processor coupled to a memory, the
memory comprising machine-readable instructions configured to cause the
processor to: receive a request from a liquid fuel dispenser unit, the request
comprising a unique identifier corresponding to a first liquid fuel canister and
34
requested fuel refill amount; query a database comprising a plurality of
unique identifiers corresponding to a plurality of liquid fuel canisters; identify,
from the database, a customer account record corresponding to the unique
identifier of the first liquid fuel canister, the customer account record
comprising an account balance; generate a message, the message configured
to cause the liquid fuel dispenser unit to initiate a fueling operation and
dispense an amount of fuel based in part on the account balance and in part on
the requested fuel refill amount; transmit the message, via a distributed
network, to a recipient. The unique identifier can be automatically detected
from a NHC chip disposed on the canister.
[00143] The recipient of the message is the liquid fuel dispenser unit. The
unit comprises an interactive user interface (e.g., a tough screen) capable of
receiving user input (such as a requested amount of fuel, the user’s ID, etc.),
and communicating information to the user, such as information received
from the server. The system comprises machine readable instructions stored
in a memory at the dispenser unit and configured to instruct a processor at
the dispenser unit to carry out the instructions received from the server.
[00144] A mobile application (e.g., for a smartphone or other mobile device)
may be used by a user, the application enabling the user to review a balance,
review a transaction history, and earn credit for referring new customers.
The application can also use GPS or other geo-location methods to identify a
refuelling point closest to the user.
[00145] The invention pertains to liquid fuel cooking apparatuses and
systems. A liquid fuel cooking apparatus as described is suitable for
consumers in resource-constrained environments, and is an effective
alternative to traditional solid fuel stoves. The systems as described provide
safe, reliable, convenient, and relatively inexpensive means for providing
liquid fuel to the cooking apparatus, with minimal human involvement and
substantial flexibility afforded to the consumer. The apparatus and systems
are environmentally friendly as reducing dependency on solid fuels while
minimizing release of liquid fuel vapours and minimizing the risk of spillage.
[00146] Various embodiments of the invention are described more fully
herein with reference to the accompanying drawings. The invention herein
35
may be embodied in many different forms and should not be construed as
limited to the embodiments set forth in the drawings; rather, these
embodiments are provided to provide further illustrative non-limiting
examples. The drawings are not necessarily to scale.
[00147] Throughout this disclosure, use of the term “server” is meant to
include any computer system containing a processor and memory, and
capable of containing or accessing computer instructions suitable for
instructing the processor to carry out any desired steps. The server may be a
traditional server, a desktop computer, a laptop, or in some cases and where
appropriate, a tablet or mobile phone. The server may also be a virtual server,
wherein the processor and memory are cloud-based.
[00148] The methods and devices described herein include a memory
coupled to the processor. Herein, the memory is a computer-readable nontransitory
storage medium or media, which may include one or more
semiconductor-based or other integrated circuits (ICs) (such, as for example,
field-programmable gate arrays (FPGAs) or application-specific ICs (ASICs)),
hard disk drives (HDDs), hybrid hard drives (HHDs), optical discs, optical disc
drives (ODDs), magneto-optical discs, magneto-optical drives, floppy
diskettes, floppy disk drives (FDDs), magnetic tapes, solid-state drives (SSDs),
RAM-drives, SECURE DIGITAL cards or drives, any other suitable computerreadable
non-transitory storage media, or any suitable combination of two or
more of these, where appropriate. A computer-readable non-transitory
storage medium may be volatile, non-volatile, or a combination of volatile and
non-volatile, where appropriate.
[00149] Throughout this disclosure, use of the term "or" is inclusive and not
exclusive, unless otherwise indicated expressly or by context. Therefore,
herein, "A or B" means "A, B, or both," unless expressly indicated otherwise or
indicated otherwise by context. Moreover, "and" is both joint and several,
unless otherwise indicated expressly or by context. Therefore, herein, "A and
B" means "A and B, jointly or severally," unless expressly indicated otherwise
or indicated otherwise by context.
[00150] It is to be understood that while the invention has been described
in conjunction with examples of specific embodiments thereof, that the
36
foregoing description and the examples that follow are intended to illustrate
and not limit the scope of the invention. It will be understood by those skilled
in the art that various changes may be made and equivalents may be
substituted without departing from the scope of the invention, and further
that other aspects, advantages and modifications will be apparent to those
skilled in the art to which the invention pertains. The pertinent parts of all
publications mentioned herein are incorporated by reference. All
combinations of the embodiments described herein are intended to be part of
the invention, as if such combinations had been laboriously set forth in this
disclosure.
37
WE CLAIM:
1. A reusable liquid fuel canister comprising:
a one-piece housing defining an internal volume;
an opening on a first end wall of the housing, the opening providing
access to the internal volume;
a shoulder assembly covering the opening and forming a mechanical
connection with the first end wall or a side wall of the housing; and
a valve assembly contacting the shoulder assembly and forming a fluidtight
seal with the opening, wherein the valve assembly comprises: a dedicated
liquid fuel flow channel, and a dedicated vapor flow channel axially disposed
within the liquid fuel flow channel.
2. The canister of claim 1, wherein the valve assembly is moveable between a
default first position and a second position when mated with a docking valve,
wherein in the first position the valve assembly is closed and provides a fluidtight
seal preventing fluids from entering or exiting the internal volume via the
liquid fuel flow channel or the vapor flow channel, and wherein in the second
position the valve assembly is open and provides for counter-flow of liquid fuel
and vapor via the liquid fuel flow channel and the vapor flow channel,
respectively.
3. The canister of claim 1, further comprising at least one locking cam disposed
within the shoulder assembly and configured to form a mechanical connection
with a docking groove on a docking valve.
4. The canister of claim 1, wherein the vapor flow channel comprises a tube
extending from the opening through the internal volume and terminating at a
distal end comprising a spring-loaded push valve.
38
5. The canister of claim 1, wherein the shoulder assembly screws onto a
threaded neck portion of the housing to form a fluid tight seal.
6. The canister of claim 1, further comprising an NFC chip attached to the
housing, the shoulder assembly, or the valve assembly, wherein the NFC chip is
configured to uniquely identify the liquid fuel canister to an NFC chip reader
device.
7. A method of using the liquid fuel canister of claim 1, the method comprising:
mating the valve assembly with a docking valve on a liquid fuel stove so as to
form a fluid-tight seal there between, and such that liquid fuel is gravity
transferred into a stove tank or burner fuel reservoir in the liquid fuel stove.
8. A method of refilling the liquid fuel canister of claim 1, the method comprising:
mating the valve assembly with a docking valve on a liquid fuel refueling station
so as to form a fluid-tight seal there between, and such that liquid fuel is gravity
transferred into the internal volume from a supply tank in the liquid fuel
refueling station.
9. A liquid fuel stove comprising:
a liquid fuel burner element, the liquid fuel burner element comprising a
combustion chamber in communication with a burner fuel reservoir;
a stove tank in fluid communication with the burner fuel reservoir via a
fuel supply tube, wherein a proximal end of the fuel supply tube forms a fluidtight
seal with the stove tank, and a distal end of the fuel supply tube forms a
fluid-tight seal with the burner fuel reservoir;
a docking valve configured to form a reversible fluid-tight docking seal
with a removable fuel canister such that fuel can flow into the stove tank from
the removable fuel canister.
10. A liquid fuel stove comprising:
a liquid fuel burner element, the liquid fuel burner element comprising a
combustion chamber in communication with a burner fuel reservoir;
39
a manifold in fluid communication with the burner fuel reservoir via a
fuel supply tube, wherein a distal end of the fuel supply tube forms a fluid-tight
seal with the burner fuel reservoir;
a docking valve configured to form a reversible fluid-tight docking seal
with a removable fuel canister such that fuel can flow into the manifold from the
removable fuel canister.
11. The liquid fuel stove of claim 10, wherein the combustion chamber is tapered
and configured to direct a flame to the centre of the liquid fuel burner element.
12. The liquid fuel stove of claim 10, further comprising a removable fuel
canister, the removable fuel canister comprising a valve assembly configured to
form a fluid-tight seal with the docking valve such that the removable fuel
canister is in fluid communication with the stove tank via the fuel supply tube.
13. The liquid fuel stove of claim 10, wherein the fuel supply tube further
comprises a T-junction and a second distal end forming a fluid-tight seal with a
second burner fuel reservoir of a second liquid fuel burner element.
14. The liquid fuel stove of claim 10, wherein the housing comprises an opening
in a body panel that allows direct access to an ignition position located between
the burner fuel reservoir and the combustion chamber.
15. The liquid fuel stove of claim 10, further comprising a float valve disposed
within the docking valve, the float valve configured to move from an open
position to a closed position when the stove tank is full of liquid fuel, wherein
when the float valve is in the closed position liquid fuel is prevented from
entering the stove tank from a removable fuel canister.
16. The liquid fuel stove of claim 10, wherein the docking valve comprises a
docking groove configured to form a mechanical connection with at least one
locking cam disposed within the shoulder assembly of the removable fuel
canister.
40
17. The liquid fuel stove of claim 10, further comprising a flame regulator,
wherein the flame regulator operates a shutter operable to regulate a flame at
the liquid fuel burner element and simultaneously operates a fuel cap lock
operable to lock a fuel cap covering the docking valve.
18. The liquid fuel stove of claim 10, further comprising a shutter disposed
between the burner fuel reservoir and the combustion chamber and operable to
regulate a flame at the liquid fuel burner element, wherein the shutter and
combustion chamber are configured to ensure the flame is centrally located
above the burner fuel reservoir regardless of a flame level setting or a regulator
position, wherein such centrally located flame is effective to evenly heat a pot
placed on the burner and to enable a stable low simmer.
19. A liquid fuel dispenser unit comprising:
a supply fuel tank;
an electronic regulator configured to measure and control dispensing of
fuel from the supply fuel tank, wherein the electronic regulator is configured to
be in electrical communication with a server via a distributed network; and
a docking valve in fluid communication with the supply fuel tank, the
docking valve configured to form a fluid-tight seal with a valve assembly of a
reusable liquid fuel canister and to allow gravity-fed transfer of fuel from the
supply tank to the reusable liquid fuel canister, wherein the fluid-tight seal
comprises a fluid flow channel and a vapor flow channel.
20. The liquid fuel dispenser unit of claim 19, wherein the electronic regulator is
operatively connected to a valve controlling fuel flow through an exit port of the
supply fuel tank.
21. The liquid fuel dispenser unit of claim 19, further comprising an NFC chip
reader disposed proximal to the docking valve and configured to read a unique
identifier from an NFC chip disposed on a reusable liquid fuel canister when the
reusable liquid fuel canister forms a fluid-tight seal with the docking valve.
41
22. The liquid fuel dispenser unit of claim 19, wherein the regulator is configured
to control fuel dispensing from the supply tank to the liquid fuel canister based
on a user input or a signal received from a server.
23. The liquid fuel dispenser unit of claim 19, further comprising an interactive
user display, and wherein the interactive user display is configured to receive
input from a user and to display output received from the server.
24. The liquid fuel dispenser unit of claim 25, wherein the user display is further
configured to display an output selected from fuel balance, transaction history,
training material, promotional material, and purchase of various products and
services.
25. The liquid fuel dispenser unit of claim 19, further comprising a sensor
configured to detect a liquid fuel level in the supply fuel tank, and wherein the
fuel dispenser unit is configured to send a refueling request to a server via a
distributed network when the liquid fuel level passes below a predetermined
threshold.
26. A method of operating the liquid fuel dispenser unit of claim 19, the method
comprising: automatically monitoring a liquid fuel level in the supply fuel tank,
and automatically transmitting an alert to a server to dispatch a resupply vehicle
when the liquid level passes below a configured threshold.
27. A liquid fuel dispensing system comprising the liquid fuel dispenser unit of
claim 19 and a server configured to communicate with the electronic regulator
via the distributed network.
28. The liquid fuel dispensing system of claim 27, further comprising a user
liquid fuel stove, the user liquid fuel stove comprising a docking valve configured
to form a fluid-tight seal with the valve assembly of the reusable liquid fuel
canister.
42
29. The liquid fuel dispensing system of claim 27, further comprising a reusable
liquid fuel canister comprising a valve assembly configured to reversibly dock to
the docking valve of the liquid fuel dispensing system and further configured to
reversibly dock to a docking valve of a user liquid fuel stove.
30. The liquid fuel dispensing system of claim 27, further comprising a server
configured to communicate with the electronic regulator via the distributed
network, wherein the server maintains a registry of unique identifiers
corresponding to a plurality of reusable liquid fuel canisters, each reusable liquid
fuel canister comprising a valve assembly configured to form a fluid-tight seal
with the docking valve.
31. The liquid fuel dispenser system of claim 27, further comprising an NFC chip
reader proximal to the docking valve, wherein:
the NFC chip reader is configured to read a unique identifier code from an
NFC chip in a liquid fuel canister upon docking of the liquid fuel canister to the
docking valve;
the liquid fuel dispenser unit is configured to communicate the unique
code to a server via a distributed network;
the server is configured to recognize the unique code and associate the
unique code with a stored user account; and
the liquid fuel dispenser is further configured to receive an instruction
from the server via the distributed network, the instruction based on a status of
the user account.
32. The liquid fuel dispensing system of claim 27, further comprising a reusable
liquid fuel canister comprising a valve assembly, wherein the valve assembly is
configured to form a fluid-tight seal with a docking valve of a stove and with the
docking valve of the liquid fuel dispenser unit.
43
33. A system for controlled dispensing of a liquid fuel, the system comprising a
processor coupled to a memory, the memory comprising machine-readable
instructions configured to cause the processor to:
receive a request from a liquid fuel dispenser unit, the request comprising
a unique identifier corresponding to a first liquid fuel canister and requested fuel
refill amount;
query a database comprising a plurality of unique identifiers
corresponding to a plurality of liquid fuel canisters;
identify, from the database, a customer account record corresponding to
the unique identifier of the first liquid fuel canister, the customer account record
comprising an account balance;
generate a message, the message configured to cause the liquid fuel
dispenser unit to initiate a fueling operation and dispense an amount of fuel
based in part on the account balance and in part on the requested fuel refill
amount;
transmit the message, via a distributed network, to a recipient.