TECHNICAL FIELD
This invention relates to the conversion of Municipal Solid Waste (MSW) into
5 charcoal and, more particularly, to a system and associated method of processing
such municipal waste into usable charcoal and volatile gas in an environmentally
friendly manner. Charcoal can be used as coal in industrial establishment by
replacing fossil fuel whereas the volatile gas shall be used in burners of system
itself for heating of reactor and other accessories. This makes the system self10 sustained and more economical for commercial use. Further by applying suitable
technology, this volatile gas can be used in the production of hydrogen (H2) and
dimethyl ether (DME) to make it more economical and eco-friendlier.
BACKGROUND
15 Background description includes information that may be useful in understanding
the present invention. It is not an admission that any of the information provided
herein is prior art or relevant to the presently claimed invention, or that any
publication specifically or implicitly referenced in prior art.
20 Municipal solid waste is commonly incinerated in a combustion process at high
temperatures such as 900 Deg Celsius. In this incarnation process solid waste
directly fetches to the combustor in oxygen rich environment and the amount of
heat generated from burning is utilized for generation of steam for further
electricity generation. One potential problem with such incineration is emission.
25 The incinerator may contain toxic and other unwanted pollutants dangerous to
human health and the environment. Another problem with incarnating municipal
solid waste is that the resultant ash must be sent to a particular type of landfill
subject to restrictive environmental regulations. In case if it is dumped at landfill
site, then it has very adverse effect over the environment, soil, and underground
30 water.
3
Therefore, there is a need in the industry for a process of treating municipal solid
waste in an environmentally friendly manner which uses all the residual by
product of the process. There is also a need for a process of treating municipal
solid waste in an environmentally friendly manner which can generate electricity.
5
SUMMARY
The following presents a simplified summary of the subject matter in order to
provide a basic understanding of some aspects of subject matter embodiments.
This summary is not an extensive overview of the subject matter. It is not
10 intended to identify key/critical elements of the embodiments or to delineate the
scope of the subject matter. Its sole purpose is to present some concepts of the
subject matter in a simplified form as a prelude to the more detailed description
that is presented later.
15 A waste conversion system disclosed here addresses the above-mentioned need a
process of treating municipal solid waste in an environmentally friendly manner
which uses all the residual by product of the process. The waste conversion
system disclosed here comprises a hopper, a coarse feeder, a weigh feeder, a
reactor, and a cooling segment. The hopper stores the segregated municipal solid
20 waste MSW as buffer feed stock for a reactor, where the hopper provides a
constant feed of the MSW to the reactor for continuous operation of the reactor.
The coarse feeder is connected to the hopper, where the coarse feeder feeds
definite amount of MSW into the reactor. The weigh feeder is connected to the
coarse feeder to receive the MSW, where the weigh feeder pushes the MSW feed
25 into the reactor. The weigh feeder measures weight of the MSW that is fed into
the reactor. The reactor is configured to receive the MSW via a set of hydraulic
pushers and heats the segregated MSW to a predefined temperature in an oxygen
deficient space, which causes the MSW to lose moisture and changes phase of the
MSW to charcoal. The cooling segment receives the charcoal from the reactor and
30 cools down the charcoal to avoid auto ignition.
4
In an embodiment, the coarse feeder is connected to an exit gate of the hopper,
and is operated using a hydraulic pusher, where the coarse feeder feeds a
predefined quantity of MSW from the hopper via the hydraulic pusher. The feed
of the MSW is controllable with the number of operation cycle of coarse feeder
5 through a logic control. In an embodiment, the coarse feeder pushes the MSW
forward and the MSW falls into the weigh feeder, and the weigh feeder comprises
the hydraulic pusher to push the MSW feed into the reactor. The weigh feeder
measures weight of the MSW entering inside the reactor by means of load cells
equipped at the weigh feeder, which provides feedback to plant PLC
10 programmable logic control system to control the process.
In an embodiment, the hydraulic pusher is positioned in the coarse feeder and the
weigh feeder, where the hydraulic pusher comprises feeder plates. The hydraulic
pusher consists of a piston rod which moves back and forth using a power pack
15 assembly, where the coarse feeder and the weigh feeder are operated by the power
pack assembly that uses enclosed fluid to transfer energy to subsequently create
rotary motion, linear motion, and force. In an embodiment, the waste conversion
system further comprises tubes through which pressurized hydraulic oil is
transferred. The tubes are connected to the hydraulic pusher to provide to and fro
20 motion to the hydraulic pusher and the feeder plate.
In an embodiment, after the weigh feeder measures the weight of the MSW, the
weigh feeder pushes the MSW inside the first zone of the reactor through an inlet
chute. Moving baffles and fixed baffles are provided to prevent the ingress of air
25 inside the reactor, where the moving baffle is hinge supported and moved up
along the MSW to make way and return when the feeding is not in process. In an
embodiment, the reactor comprises: the first zone defining a pre-heating zone with
a temperature range of 50 degree Celsius to 150 degree Celsius), a second zone
defining heating zone with a temperature range of 100 degree Celsius to 200
30 degree Celsius, a third zone defining torrefaction zone with a temperature range of
5
250 degree Celsius to 350 degree Celsius, and a fourth zone defining cooling zone
with a temperature below 60 degree Celsius.
In an embodiment, the reactor comprises a rotary inner shell connected with a
5 girth gear for conversion process of the MSW, and the girth gear is positioned
adjacent to the rotary inner shell. The girth gear is connected with a main electric
drive and a gear box, which facilitates rotary motion for the reactor. The gear box
provides rotary torque and reduced rpm to the reactor and the main electric drive
transfers rotary motion through a belt and pulley arrangement. The reactor rotates
10 between 1-6 rpm based on operational capacity and parameter of the reactor,
which is controlled through a variable frequency drive VFD. In an embodiment,
the reactor comprises an outer stationary shell that is positioned over a rotary
inner shell for movement of hot air in space between outer stationary shell and the
rotary inner shell. The outer stationary shell is insulated for thermal efficiency of
15 the heating system and the reactor, and where the outer stationary shell is sealed
using layers of leaf seal that prevent ingress of air between stationary outer
stationary shell or adopter and the rotary inner shell.
In an embodiment, the rotary inner shell is fitted with one or more guide rings,
20 which rotates over rollers positioned alongside a bracket for seamless rotation of
the rotary inner shell. The rollers are positioned alongside the bracket of the
reactor on which the guide ring rotates and prevents the reactor from derailing. In
an embodiment, the waste conversion system further comprises a discharge feeder
that is connected to the cooling segment, where the charcoal is discharged through
25 the discharge feeder, which operates through the power pack assembly provided at
discharge gate of the reactor, where the discharge feeder maintains sealing of the
reactor to avoid any ingress of air and leakage of volatile gases, where the
charcoal discharged from reactor falls on the discharge feeder through a discharge
chute. The discharge feeder pushes the discharged charcoal to either side of the
30 discharge feeder.
6
In an embodiment, the waste conversion system further comprises a cyclone
separator that is connected to outlet of the cooling segment and the discharge
feeder to separate dust, mist and solid particles from volatile gases that are
generated in the waste conversion system. The dust, mist and solid particles are
5 pushed based on their respective masses to outer edges of the cyclone separator
due to centrifugal force and any incoming volatile gas is forced to adopt a fastrevolving spiral movement, which causes the separation of the dust, mist and solid
particles from the volatile gases. In an embodiment, the waste conversion system
further comprises a set of burners and a centrifugal volatile gas blower. The
10 burners are installed below the outer stationary shell of the reactor to provide
required heat energy for the conversion process in the reactor that uses the volatile
gas as a fuel in the burners. The centrifugal volatile gas blower is positioned in
line from the cyclone separator to regulate the flow of the volatile gas towards the
burners. The centrifugal air blower is positioned adjacent to the burners to supply
15 required amount of air for complete and efficient combustion of volatile gas in the
burners.
In an embodiment, the waste conversion system further comprises a flue gas
blower that transfers the flue gases towards the chimney. The flue gases are
20 generated after combustion in the burner and travels across the reactor via space
between the outer stationary shell and the rotary inner shell, and the flue gas
blower maintains pressure within combustion section of the reactor and draws the
flue gases to escape via the chimney. In an embodiment, the waste conversion
system further comprises a cooling system and a specially designed moving joint.
25 The cooling system is positioned to maintain sufficient flow and pressure inside
the cooling segment. The moving joint that comprises a fixed water inlet and
outlet, which facilitates water connection through moving pipes that are attached
with the rotating cooling segment. The fixed water inlet and outlet are provided at
discharge chute of the reactor where cooling water is required to cool down the
30 coal temperature and avoid any self-ignition.
7
In an embodiment, the waste conversion system further comprises thermocouple
IR sensors that are connected to the outer stationary shell to measure the
temperature of the rotary inner shell, and the measurement is used as a reference
to control the burner and resulting temperature from the burner. In an
5 embodiment, the process involved in the reactor comprises the following steps.
Heating the reactor using the external source of heating. In response to internally
generated inflammable volatile gas after heating inside inner shell, switching off
the external heat source and heating with internally produced volatile or syn gas
and burners installed, where the external heat source is switched OFF
10 automatically between external heat source and internal source of heating though
volatile gas. Setting operation of the external heat source is in standby mode and
the external heat source is switched ON only when volatile gas generation inside
the inner shell is low or insufficient and the external heat source is switched OFF
once a definite temperature is achieved. Controlling the ON and OFF operation of
15 the external heat source via the thermocouple IR sensors that are installed adjacent
to the burner and the reactor, where the controlled operation makes the process
self-sustainable in terms for fuel for heating and reduces reduce dependency upon
external heat source or fuel to reduce cost.
20 BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
The foregoing and further objects, features, and advantages of the present subject
matter will become apparent from the following description of exemplary
embodiments with reference to the accompanying drawings, wherein numerals are
used to represent like elements.
25
It is to be noted, however, that the appended drawings illustrate only typical
embodiments of the present subject matter, and are, therefore, not to be
considered for limiting of its scope, for the subject matter may admit to other
equally effective embodiments.
30
8
Figure 1A illustrates a schematic view of the or the waste conversion system used
to practice the method of the present invention, as an example embodiment of the
present disclosure.
5 Figure 1B illustrates a left-side portion along the axis XX of the Figure 1A to
provide a clear view of the components of the waste conversion system, as an
example embodiment of the present disclosure.
Figure 1C illustrates a right-side portion along the axis XX of the Figure 1A to
10 provide a clear view of the components of the waste conversion system, as an
example embodiment of the present disclosure.
Figure 2 illustrates a feeder assembly of the waste conversion system as shown in
Figure 1A, as an example embodiment of the present disclosure.
15
Figure 3 illustrates moving joint arrangement within the waste conversion system
as shown in Figure 1A, as an example embodiment of the present disclosure.
Figure 4 illustrates a schematic flow of process involved in the waste conversion
20 system as shown in Figure 1A, as an example embodiment of the present
disclosure.
DETAILED DESCRIPTION
25 The following presents a detailed description of various embodiments of the
present subject matter with reference to the accompanying drawings. The
embodiments of the present subject matter are described in detail with reference to
the accompanying drawings. However, the present subject matter is not limited to
these embodiments which are only provided to explain more clearly the present
30 subject matter to a person skilled in the art of the present disclosure. In the
accompanying drawings, reference numerals are used to indicate like components.
9
The specification may refer to “an”, “one”, “different” or “some” embodiment(s)
in several locations. This does not necessarily imply that each such reference is to
the same embodiment(s), or that the feature only applies to a single embodiment.
5 Single features of different embodiments may also be combined to provide other
embodiments.
As used herein, the singular forms “a”, “an” and “the” are intended to include the
plural forms as well, unless expressly stated otherwise. It will be further
10 understood that the terms “includes”, “comprises”, “including” and/or
“comprising” when used in this specification, specify the presence of stated
features, integers, steps, operations, elements, and/or components, but do not
preclude the presence or addition of one or more other features, integers, steps,
operations, elements, components, and/or groups thereof. It will be understood
15 that when an element is referred to as being “attached” or “connected” or
“coupled” or “mounted” to another element, it can be directly attached or
connected or coupled to the other element or intervening elements may be present.
As used herein, the term “and/or” includes any and all combinations and
arrangements of one or more of the associated listed items.
20
The figures depict a simplified structure only showing some elements and
functional entities, all being logical units whose implementation may differ from
what is shown.
25 In general, the concept of this type of Waste-To-Energy plant is basically a waste
management facility that converts waste to produce Charcoal, which can be
further used as a coal in conventional thermal power plant. This type of plant is
sometimes called a Waste-to Coal, municipal waste conversion, energy recovery,
or resource recovery plant. Waste-to-coal is being increasingly looked at as an
30 alternative against conventional coal which is fossil fuel. The biggest advantage is
utilization of waste into conversion of energy without depleting the carbon loaded
10
fossil fuel. Thus, saving natural resources and solving the eco-social issue by
processing municipal waste.
Due to lack of practice at source segregation of waste, Indian MSW is typically
5 composed of a wide variety of materials, including plastics, paper, food waste,
and other organic materials. It also contains metals, construction material (inert),
utensils, cans, aluminium foils, and other pollutants. These metals and inert
materials are not ideal for making into Charcoal. With MBPL technology, now it
is possible to convert municipal solid waste (MSW) into charcoal (which is later
10 termed as Green Coal) using heat reaction process and efficient method of sorting
and processing to separate the waste and metals/inert particles.
It is important to note that MSW contains a diverse range of materials that are not
typically found in biomass feedstock. Due to this reason, the process of charcoal
15 generation is more complex and requires a different approach to the process. This
process of charcoal generation is basically torrefaction process in which thermal
treatment process takes place inside a rotating large drum (which is termed as the
REACTOR). The process inside the Reactor involves heating of segregated MSW
to a high temperature (up to 350°C) in the oxygen deficient atmosphere. This
20 causes the MSW to lose moisture and causes phase changes in the material that
make it more similar to conventional coal. After heating of reactor, the flue gas is
cleaned by using gas cleaning system in which the temperature gets cooled down
and passed through cleaning system in which the contaminants such as SO2 and
NOx gases along with particulate matter are removed. It also continuously
25 monitors the level of emissions being discharged from chimney.
The process to convert Municipal Solid Waste (MSW) to Green Coal (charcoal)
via reactor, involves the following steps:
a. Pre-Sorting: This is first step is where the MSW is churned inside store pit
30 to remove some moisture in natural way. Also, the waste is mixed to make it
homogenous. The large inert materials or metals can be sorted out here itself.
11
b. Preheating: This is required to remove the maximum moisture content at
this stage by using specially designed Rotary Drum Dryer cum pre-shredder. After
heating, the moisture that remains here is approximately 10% in the MSW.
c. Sorting: The next step is to sort and separate the waste into different
5 categories by mechanical segregation method. Most of the metals and inert
materials are sorted out here itself. This increases the efficiency of the reactor to
the optimum level.
d. Pre-treatment: The next step would be to shred, chop or grind the sorted
waste into small pieces, to make it easier to handle and process. This step is also
10 important to make it homogeneous material and thus improve the heat transfer
during process inside reactor.
e. Heating of Reactor: Initially reactor is heated with external source which
can be biomass fired gasifier burners or Biomass burners. The hot gasses are
generated to the temperature of 600 deg. C. Once torrefaction process starts, it
15 starts producing volatile gas. This volatile gas, once become flammable, is
diverted to the burners and the external source will be automatically switch-off in
phased manner. This process makes system self-sustainable. The external heat
source is required only when the required temperature is dipping.
f. Charcoal Reaction: The pre-treated waste would then be fed into a
20 Reactor. The Reactor is sealed to the level to allow minimum amount of air and
heated to a temperature between 50-350°C, to remove moisture and break down
the waste into its component parts as high GCV charcoal. This is indirect heating
where the outer shell is heated by firing a set of burners and material which are
heated inside the reactor. The reactor is divided in following zones as per different
25 temperature zones.
o Pre-heating zone (500 C to 1500 C)
o Heating Zone (1000 C to 2000 C)
o Torrefaction Zone (2500 C to 3500 C)
o Cooling Zone (Less than 600 C)
12
g. Cooling and conditioning: Once the torrefaction process is complete, the
material would need to be cooled and conditioned before it can be used as
charcoal. This is done in last zone of reactor with external cooling water.
h. Pelletising and packaging: The cooled Charcoal is then be mixed with
5 binder, pelletised, dried and packaged for transport and storage. This final product
can be termed as MBL Green Coal.
MBL Green Coal is used as a fuel in power plants, as well as in other industrial
processes. It burns more cleanly and efficiently than raw biomass or RDF (Refuse
10 Derive Fuel) and has a higher energy density than RDF. It also can be stored and
transported more easily than raw biomass or RDF. Additionally, charcoal pellets
have better grindability and more suitable for use in pulverized coal-fired power
plants.
15 Referring to Figures 1A-1C, Figure 1A illustrates a schematic view of the or the
waste conversion system (60) used to practice the method of the present
invention, Figure 1B illustrates a left-side portion along the axis XX of the
Figure 1A to provide a clear view of the components of the waste conversion
system (60), and Figure 1C illustrates a right-side portion along the axis XX of
20 the Figure 1A to provide a clear view of the components of the waste conversion
system (60), as an example embodiment of the present disclosure.
As shown in Figures 1B and 1C, the waste conversion system (60) disclosed here
comprises a hopper (1), a coarse feeder (2), a weigh feeder (5), a reactor (50), and
25 a cooling segment (17). The hopper (1) stores the segregated municipal solid
waste (MSW) as buffer feed stock for the reactor (50), where the hopper (1)
provides a constant feed of the MSW to the reactor (50) for continuous operation
of the reactor (50). Main objective of this MSW hopper (1) is to facilitate enough
feed stock for constant feed and continuous operation of the reactor (50). The
30 coarse feeder (2) is connected to the hopper (1), where the coarse feeder (2) feeds
a definite amount of MSW into the reactor (50). The coarse feeder (2) is specially
13
designed and mounted at just bottom/exit of MSW hopper (1) and operated via
hydraulically assisted pusher members. The coarse feeder (2) feeds a definite
quantity of material (equivalent to volume of box) from MSW hopper (1) to the
coarse feeder (2). The coarse feeder (2) decides the amount of feed material to be
5 fed into the reactor (50). The feed can be controlled with the number of operation
cycles of coarse feeder (2) through logic controls.
As shown in Figures 1B and 1C, the weigh feeder (5) is connected to the coarse
feeder (2) to receive the MSW, where the weigh feeder (5) pushes the MSW feed
10 into the reactor (50). The weigh feeder (5) measures weight of the MSW that is
fed into the reactor (50). The coarse feeder (2) pushes the material forward and it
falls into the specially designed weigh feeder (5) basket, where a feeder pusher
plate (3) (Figure 2) is provided to push the feed material inside of reactor (50).
The weigh feeder (5) also measures the weight of feed material entering inside the
15 reactor (50) by means of load cells (5a). The reactor (50) is configured to receive
the MSW via a set of hydraulic pushers (3a) and heats the segregated MSW to a
predefined temperature in an oxygen deficient space, which causes the MSW to
lose moisture and changes phase of the MSW to charcoal. In an example, MSW is
fed into the reactor (50) inlet by means of hydraulic pusher (3a). There are two
20 hydraulic pushers (3a) provided, one for coarse feeder (2) and other for weigh
feeder (5). A hydraulic cylinder (explained later) is equipped with hydraulic
pusher (3a) to provide adequate movement to the feeder plate (3). The hydraulic
pusher (3a) consists of a cylinder barrel, in which a piston is connected to a piston
rod (3b) that moves back and forth with the help of a power pack assembly (4).
25 Finally, the cooling segment (17) receives the charcoal from the reactor (50) and
cools down the charcoal to avoid auto ignition of charcoal.
As described previously, the coarse feeder (2) is connected to an exit of the
hopper (1) and is operated using a hydraulic pusher (3a), where the coarse feeder
30 (2) feeds a predefined quantity of MSW from the hopper (1) via the hydraulic
pusher (3a). The feed of the MSW is controllable with the number of operation
14
cycle of coarse feeder (2) through a logic control. The coarse feeder (2) pushes the
MSW forward and the MSW falls into the weigh feeder (5), and the weigh feeder
(5) comprises the hydraulic pusher (3a), as shown in Figure 2, to push the MSW
feed into the reactor (50). The weigh feeder (5) measures weight of the MSW
5 entering inside the reactor (50) by means of load cells (5a) equipped at the weigh
feeder (5), which provides feedback to plant PLC (programmable logic control)
system to control the process.
As shown in Figures 1C and 2, the hydraulic pusher (3a) is positioned in the
10 coarse feeder (2) and the weigh feeder (5), where the hydraulic pusher (3a)
comprises feeder plates (3). The hydraulic pusher (3a) consists of a piston rod (3b)
which moves back and forth using a power pack assembly (4), where the coarse
feeder (2) and the weigh feeder (5) are operated by the power pack assembly (4)
that uses enclosed fluid to transfer energy to subsequently create rotary motion,
15 linear motion, and force. In an example embodiment, both the feeders are
operated by an individual or common power pack system (4) which is a hydraulic
system that employs enclosed fluid to transfer energy from one source to another,
and subsequently create rotary motion, linear motion, or force. The power pack
system (4) provides sufficient power needed for this transfer of fluid.
20
After the weigh feeder (5) measures the weight of the MSW, the weigh feeder (5)
pushes the MSW inside the first zone (10a), as shown in Figure 1B, of the reactor
(50) through an inlet chute (6). Moving baffles (6a) and fixed baffles (6b) are
provided to prevent the ingress of air inside the reactor (50), where the moving
25 baffle (6a) is hinge (6c) supported and moved up along the MSW to make way
and return when the feeding is not in process. The reactor (50) comprises: the first
zone (10a) defining a pre-heating zone with a temperature range of 500
degree
Celsius to 150 degree Celsius), a second zone (10b) defining heating zone with a
temperature range of 100 degree Celsius to 200 degree Celsius, a third zone (10c
30 and 10d) defining torrefaction zone with a temperature range of 250 degree
15
Celsius to 350 degree Celsius, and a fourth zone (17) defining cooling zone with a
temperature below 60 degree Celsius.
As shown in Figure 1B, the rotary inner shell (10) is fitted with one or more
5 guide rings (13), which rotates over rollers (14) positioned alongside a bracket
(14a) for seamless rotation of the rotary inner shell (10). The rollers (14) are
positioned alongside the bracket (14a) of the reactor (50) on which the guide ring
(13) rotates and prevents the reactor (50) from derailing. The waste conversion
system (60) also comprises a discharge feeder (18) that is connected to the cooling
10 segment (17), where the charcoal is discharged through the discharge feeder (18),
which operates through the power pack assembly (4) provided at discharge gate of
the reactor (50). Here, the discharge feeder (18) maintains sealing of the reactor
(50) to avoid any ingress of air and leakage of volatile gases, where the charcoal
discharged from the reactor (50) falls on the discharge feeder (18) through a
15 discharge chute (18a), and where the discharge feeder (18) pushes the discharged
charcoal to either side of the discharge feeder (18).
As shown in Figure 1C, the waste conversion system (60) also comprises a
cyclone separator (21) that is connected to outlet of the cooling segment (17) and
20 the discharge feeder (18) to separate dust, mist and solid particles from volatile
gases that are generated in the waste conversion system (60). The dust, mist and
solid particles are pushed based on their respective masses to outer edges of the
cyclone separator (21) due to centrifugal force and any incoming volatile gas is
forced to adopt a fast-revolving spiral movement, which causes the separation of
25 the dust, mist and solid particles from the volatile gases. Furthermore, a water seal
safety valve is provided to prevent the rotary inner shell (10) from over
pressurization. Water in the tank seals the gas and atmospheric air, thus allowing
the water seal to break whenever the rotary inner shell (10) is pressurized.
30 As shown in Figure 1C, the waste conversion system (60) also comprises a set of
burners (16) and a centrifugal air blower (15b). The burners (16) are installed
16
below the outer stationary shell (11) of the reactor (50) to provide required heat
energy for the conversion process in the reactor (50) that uses the volatile gas as a
fuel in the burners (16). The centrifugal volatile gas blower (15a) is positioned in
line from the cyclone separator (21) to regulate the flow of the volatile gas
5 towards the burners (16). The centrifugal air blower (15b) is positioned adjacent
to the burners (16) to supply the required amount of air for complete and efficient
combustion of volatile gas in the burners (16). In an example embodiment, after
the combustion, the generated flue gas shall travel across the reactor (50) via
space between outer stationary shell (11) and the rotary inner shell (10) and to
10 maintain the proper pressure within combustion chamber, a flue gas blower (15c)
is provided, also it transfers the flue gas towards chimney (24).
As shown in Figure 1C, the waste conversion system (60) also comprises the flue
gas blower (15c) that transfers the flue gases towards the chimney (24). The flue
15 gases are generated after combustion and travels across the reactor (50) via space
between the outer stationary shell (11) and the rotary inner shell (10), and the flue
gas blower (15c) maintains pressure within combustion section of the reactor (50)
and draws the flue gases to escape via the chimney (24). Furthermore, flue gas is
treated further in gas cleaning tank (23), in which dust particles, aerosols and
20 harmful chemical washed out within this tank via treating with some catalyst.
Cleaned flue gas is further transferred to chimney (24) where escape draft is
maintained where flue gas can easily evacuate from the system.
As shown in Figure 1B, the waste conversion system (60) also comprises
25 thermocouple IR sensors (25) that are connected to the outer stationary shell (11)
to measure the temperature of the rotary inner shell (10), and the measurement is
used as a reference to control the burner (16) and resulting temperature from the
burner (16). Referring to Figures 1A-1C, the process involved in the reactor (50)
comprises the following steps. Heating the reactor (50) using the external heat
30 source (26). The external heat source (26) is, for example, 1) a biomass burner,
which is an external burner operates by using biomass as fuel. This generates high
17
temperature flame / flue gas which is used for eating of reactor (50), and b)a
Gasifier that generates volatile or syn gas which is fed to the reactor burners for
heating of reactors. The gas is generated by heating of biomass/coal RDF etc in
gasifier to generates inflammable gas.
5
In response to generation of inflammable volatile gas after heating, the external
heat source (26) is switched OFF, where the volatile gas line (16a) is switched
ON. Setting operation of the external heat source (26) in standby mode and the
external heat source (26) is switched ON only when volatile gas generation is low
10 and the external heat source (26) is switched OFF after a definite temperature is
generated from the burner (16) using volatile gas line (16a). Controlling the ON
and OFF operation of the external heat source (26) via the thermocouple IR
sensors (25) that are installed adjacent to the burner (16) and the reactor (50).
Here, the controlled operation makes the process self-sustainable in terms for fuel
15 for heating and reduces reduce dependency upon external fuel or external heat
source (26) to reduce cost.

We Claim:
1. A waste conversion system (60) comprising:
5 a hopper (1) that stores the segregated municipal solid waste (MSW) as
buffer feed stock for a reactor (50), wherein the hopper (1) provides a constant
feed of the MSW to the reactor (50) for continuous operation of reactor (50);
a coarse feeder (2) that is connected to the hopper (1), wherein the coarse
feeder (2) feeds definite amount of MSW into the reactor (50),
10 a weigh feeder (5) that is connected to the coarse feeder (2) to receive the
MSW, wherein the weigh feeder (5) pushes the MSW feed into the reactor (50),
and wherein the weigh feeder (5) measures weight of the MSW that is fed into the
reactor (50);
the reactor (50) configured to receive the MSW via a set of hydraulic
15 pushers (3a), wherein the reactor (50) heats the segregated MSW to a predefined
temperature in an oxygen deficient space, which causes the MSW to lose moisture
and changes phase of the MSW to charcoal; and
a cooling segment (17) that receives the charcoal from the reactor (50)
and cools down the charcoal to avoid auto ignition.
20
2. The waste conversion system (60) as claimed in claim 1, wherein the coarse
feeder (2) is connected to an exit of the hopper (1), and is operated using a
hydraulic pusher (3a), wherein the coarse feeder (2) feeds a predefined quantity of
MSW from the hopper (1) via the hydraulic pusher (3a), and wherein the feed of
25 the MSW is controllable with the number of operation cycle of coarse feeder (2)
through a logic control.
3. The waste conversion system (60) as claimed in claim 2, wherein the coarse
feeder (2) pushes the MSW forward and the MSW falls into the weigh feeder (5),
30 wherein the weigh feeder (5) comprises the hydraulic pusher (3a) to push the
MSW feed into the reactor (50), wherein the weigh feeder (5) measures weight of
21
the MSW entering inside the reactor (50) by means of load cells (5a) equipped at
the weigh feeder (5), which provides feedback to plant PLC (programmable logic
control) system to control the process.
5 4. The waste conversion system (60) as claimed in claim 2, wherein the hydraulic
pusher (3a) is positioned in the coarse feeder (2) and the weigh feeder (5),
wherein the hydraulic pusher (3a) comprises feeder plates (3), and wherein the
hydraulic pusher (3a) consists of a piston rod (3b) which moves back and forth
using a power pack assembly (4), wherein the coarse feeder (2) and the weigh
10 feeder (5) are operated by the power pack assembly (4) that uses enclosed fluid to
transfer energy to subsequently create rotary motion, linear motion, and force.
5. The waste conversion system (60) as claimed in claim 4, further comprising
tubes (4a) through which pressurized hydraulic oil is transferred, wherein the
15 tubes (4a) are connected to the hydraulic pusher (3a) to provide to-fro motion to
the hydraulic pusher (3a) and the feeder plate (3).
6. The waste conversion system (60) as claimed in claim 2, wherein after
measuring the weight of the MSW, the weigh feeder (5) pushes the MSW inside
20 the first zone (10a) of the reactor (50) through an inlet chute (6), wherein moving
baffles (6a) and fixed baffles (6b) are provided to prevent the ingress of air inside
the reactor (50), wherein the moving baffle (6a) is hinge (6c) supported and
moved up along the MSW to make way and return when the feeding is not in
process.
25
7. The waste conversion system (60) as claimed in claim 6, wherein the reactor
(50) comprises:
the first zone (10a), which is a pre-heating zone with a temperature range
of 50 degree Celsius to 150 degree Celsius,
30 a second zone (10b), which is a heating zone with a temperature range of
100 degree Celsius to 200 degree Celsius,
22
a third zone (10c and 10d), which is a torrefaction zone with a
temperature range of 250 degree Celsius to 350 degree Celsius, and
a fourth zone (17), which is cooling zone with a temperature below 60
degree Celsius.
5
8. The waste conversion system (60) as claimed in claim 2, wherein the reactor
(50) comprises a rotary inner shell (10) connected with a girth gear (7) for
conversion process of the MSW, wherein the girth gear (7) is positioned adjacent
to the rotary inner shell (10), wherein the girth gear (7) is connected with a main
10 electric drive (9) and a gear box (8) which facilitates rotary motion for the reactor
(50), wherein the gear box (8) provides rotary torque and reduced rpm to the
reactor (50) and the main electric drive (9) transfers rotary motion through a belt
(8b) and pulley (8a) arrangement, wherein the reactor (50) rotates between 1-6
rpm based on operational capacity and parameter of the reactor (50), which is
15 controlled through a variable frequency drive (VFD) (9a).
9. The waste conversion system (60) as claimed in claim 8, wherein the reactor
(50) comprises an outer stationary shell (11) that is positioned over the rotary
inner shell (10) for movement of hot air in space between outer stationary shell
20 (11) and the rotary inner shell (10), wherein the outer stationary shell (11) is
insulated for thermal efficiency of the heating system and the reactor (50), and
wherein the outer stationary shell (11) is sealed using layers of leaf seal (12) that
prevent ingress of air between stationary outer stationary shell (11) or adopter (6).
and the rotary inner shell (10)
25
10. The waste conversion system (60) as claimed in claim 1, wherein the rotary
inner shell (10) is fitted with one or more guide rings (13), which rotates over
rollers (14) positioned alongside a bracket (14a) for seamless rotation of the rotary
inner shell (10), and wherein the rollers (14) are positioned alongside the bracket
30 (14a) of the reactor (50) on which the guide ring (13) rotates and prevents the
reactor (50) from derailing.
23
11. The waste conversion system (60) as claimed in claim 1, further comprising a
discharge feeder (18) that is connected to the cooling segment (17), wherein the
charcoal is discharged through the discharge feeder (18), which operates through
5 the power pack assembly (4) provided at discharge gate of the reactor (50),
wherein the discharge feeder (18) maintains sealing of the reactor (50) to avoid
any ingress of air and leakage of volatile gases, wherein the charcoal discharged
from reactor (50) falls on the discharge feeder (18) through a discharge chute
(18a), and wherein the discharge feeder (18) pushes the discharged charcoal to
10 either side of the discharge feeder (18).
12. The waste conversion system (60) as claimed in claim 11, further comprising
a cyclone separator (21) that is connected to outlet of the cooling segment (17)
and the discharge feeder (18) to separate dust, mist and solid particles from
15 volatile gases that are generated in the waste conversion system (60), wherein the
dust, mist and solid particles are pushed based on their respective masses to outer
edges of the cyclone separator (21) due to centrifugal force and any incoming
volatile gas is forced to adopt a fast-revolving spiral movement, which causes the
separation of the dust, mist and solid particles from the volatile gases.
20
13. The waste conversion system (60) as claimed in claim 11, further comprising:
a set of burners (16) installed below the outer stationary shell (11) of the
reactor (50) to provide required heat energy for the conversion process in the
reactor (50) that uses the volatile gas as a fuel in the burners (16); and
25 a centrifugal volatile gas blower (15a) that is positioned in line from the
cyclone separator (21) to regulate the flow of the volatile gas towards the burners
(16); and
a centrifugal air blower (15b) that is positioned adjacent to the burners
(16) to supply required amount of air for complete and efficient combustion of
30 volatile gas in the burners (16).
24
14. The waste conversion system (60) as claimed in claim 11, further comprising
a flue gas blower (15c) that transfers the flue gases towards the chimney (24),
wherein the flue gases are generated after combustion and travels across the
5 reactor (50) via space between the outer stationary shell (11) and the rotary inner
shell (10), and wherein the flue gas blower (15c) maintains pressure within
combustion section of the reactor (50) and draws the flue gases to escape via the
chimney (24).
10 15. The waste conversion system (60) as claimed in claim 11, further comprising:
a cooling system (22) that is positioned to maintain sufficient flow and
pressure inside the cooling segment (17);
a specially designed moving joint (19) that comprises a fixed water inlet
(19a) and outlet (19b) , which facilitates water connection through moving pipes
15 (19c) that are attached with the rotating cooling segment (17), wherein the fixed
water inlet (19a) and outlet (19b) are provided at discharge chute (18a) of the
reactor (50) where cooling water is required to cool down the coal temperature
and avoid any self-ignition.
20 16. The waste conversion system (60) as claimed in claim 11, further comprising
thermocouple IR sensors (25) that are connected to the outer stationary shell (11)
to measure the temperature of the rotary inner shell (10), and wherein the
measurement is used as a reference to control the burner (16) and resulting
temperature from the burner (16).
25
17. The waste conversion system (60) as claimed in claim 11, wherein process
involved in the reactor (50) comprises the following steps:
heating the reactor (50) using the external heat source (26);
in response to generation of inflammable volatile gas after heating the
30 rotary inner shell (10), switching off the external heat source (26) and switching
25
ON the volatile gas line (16a), wherein the external heat source (26) is switched
OFF automatically;
setting operation of the external heat source (26) in standby mode and the
external heat source (26) is switched ON only when volatile gas generation is low
5 and the external heat source (26) is switched OFF after a definite temperature is
generated from the burner (16) using the volatile gas line (16a); and
controlling the ON and OFF operation of the external heat source (26)
via the thermocouple IR sensors (25) that are installed adjacent to the burner (16)
and the reactor (50), wherein the controlled operation makes the process self10 sustainable in terms for fuel for heating and reduces reduce dependency upon
external fuel to reduce cost.