DESC:FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10; rule 13)
1. TITLE: AUTOMATIC REJECT LINE, RO & PRE-RO CLEANING AND
SCALE CONTROLLING SYSTEM AND METHOD
2. APPLICANT DETAILS:
(a) NAME: A. O. Smith India Water Products Pvt Ltd
(b) NATIONALITY: An Indian Company
(c) ADDRESS: Plot No. 300, KIADB Industrial Area, Phase -2, Harohalli,
Kanakapura Taluk, Ramanagara District, 562112, Karnataka, India.
The following specification particularly describes the invention and the manner in which it is
to be performed.
2
AUTOMATIC REJECT LINE, RO & PRE-RO CLEANING AND SCALE
CONTROLLING SYSTEM AND METHOD
Field of Invention:
[001] The invention relates to a water purifier/purification apparatus with automatic
reject line, RO & pre-RO cleaning and scale controlling system and method. More
particularly, the invention provides water purifier with automatic cleaning and scale
controlling/prevention mechanism, present in reject line, based on a periodic,
automatic, intelligent, time/flow/pressure driven cleaning and scale controlling
system.
Background of the Invention:
[002] The following background discussion 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 is prior art.
[003] A domestic reverse osmosis (RO) water purifier designed with four major
stages, i.e. Pre RO filtration, RO filtration, Post RO filtration, and Concentrate water
discharge system through reject line. A reverse osmosis module generally consists of
a semi-permeable membrane within a pressure vessel that allows some water to pass
through the membrane when the water pressure is at a controlled point. As some of
the water passes through the membrane, the suspended matter, microorganisms, and
dissolved solids in the remaining water increase (concentrate). As they increase, some
may settle or precipitate on the surface of the membrane, forming a deposit that can
reduce the flow and the rated performance of the module.
[004] The concentrate water discharge system is generally designed with one flow
restrictor and a solenoid valve in parallel line. A flow restrictor in domestic reverse
osmosis system describes as a defined gauge capillary and it permits a defined flow of
concentrate water in defined pressure. A solenoid valve in reject line describes as a
control unit which electrically energized or de-energized, either shut off or allow
water flow. The actuator takes the form of an electromagnet. When energized, a
magnetic field builds up which pulls a plunger or pivoted armature against the action
of a spring. When de-energized, the plunger or pivoted armature is returned to its
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original position by the spring action. This valve is used for periodic system flushing,
bypassing the flow restrictor.
[005] The concentrated material that has deposited during the operating cycles can
solidify and it can form a scale. Bacteria proliferate during static periods and they
colonize on the downstream surface of the membranes. By the process of osmosis,
dissolved salts pass through the membranes thus contaminating the permeate side.
[006] Calcium carbonate in the feed flow of reverse osmosis system yields to
significant fouling phenomenon due to its precipitation. Fouling due to calcium
carbonate deposits becomes more significant when the solubility limit is exceeded.
The solubility limit of calcium carbonate depends on the ratio of total hardness,
calcium hardness and total alkalinity of the water. The inner diameter of the flow
restrictor capillary used in domestic high recovery RO system (50-80% of recovery) is
much lesser than the flow restrictor used in conventional RO system(30-50% of
recovery).
[007] Ion concentration in the concentrate side of the high recovery RO system is
much higher than the ion concentration in the concentrate side of the conventional RO
system in constant quality of feed water due the lesser discharge of concentrate water
in domestic high recovery RO system. In the reject side of high recovery RO system,
calcium carbonate solubility limit is much lesser than the concentrate water of
conventional RO system. Thus, in domestic high recovery RO system, the calcium
carbonate solubility ratio between feed water and concentrate water is higher than the
calcium carbonate solubility ratio between feed water and concentrate water in
domestic conventional RO system.
[008] So, the deposition of calcium carbonate in reject line of high recovery RO
system will occur much earlier than the significant drop in RO membrane flux due to
membrane fouling with calcium carbonate. The calcium carbonate deposition in reject
line leads to flow restrictor chocking and due to chocked flow restrictor the
concentrate water discharge will come down, followed by gradual increase of ionic
concentration in concentrate side of RO membrane and the percentage flux of RO
membrane will reduce significantly and finally it leads to premature fouling of RO
membrane. On the other hand the calcium carbonate deposition in solenoid valve
effects on plunger & spring movement and leads to a significant system failure in high
recovery RO system.
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[009] When the operating flux (flow) through a module decreases by 10 to 15
percent, or if the rejection of dissolved solids drops by 10 percent, the module must be
chemically cleaned with combinations of approved alkali and then by acid solutions
and rinsed until the rated performance is restored. When microorganisms form
colonies within the modules and contaminate the purified water, the modules must be
cleaned and then sanitized with an agent or agents approved by the module
manufacturer. However, a solution addressing the problem of cleaning reject line of
high recovery RO system has never been explored. Particularly, there is no purifier/
technology that can automatically perform cleaning of the reject line based on real
time and periodic sensing of the water characteristics like TDS, flow sensor, photo
sensor, pressure sensor etc.
[0010] US Patent publication US20080169006A1 provides a method of cleaning a
fouled or a scaled RO or NF membrane surface with a solution containing one or
more thermo-responsive polymers. More specifically, the method comprises: treating
the membrane surface in a membrane separation system with a solution containing
one or more TRP, wherein said TRP(Thermo response polymer) is soluble in said
solution and at least an effective amount of said TRP diffuses into a foulant layer on
said membrane surface; making insoluble said TRP diffused into said foulant layer;
optionally, rinsing the membrane. The publication mainly describes that the
membrane is treated with a solution containing TRP by circulating and/or shocking
for 10 min to 8 hours. The cleaning agent is describes as acids (including citric acid),
Polymers, monomers, enzymes, chlorine & chlorides, disinfectants, H2O2 etc. US
‘9006 essentially describes use of acids like citric acid for cleaning the fouled scale.
[0011] Chinese Patent publication CN101455931A provides an alkali reverse osmosis
membrane cleaning agent, which comprises an ethylene diamine tetra acetic acid
tetrasodium salt solution or a sodium dodecyl benzene sulfonate solution or a trimeric
sodium phosphate solution, of which the concentration is between 1 and 4 percent and
the pH value is between 10 and 12. CN ‘931 provides a method for on-line chemical
cleaning of the reverse osmosis membrane, by alternately using an acid reverse
osmosis membrane cleaning agent and the alkali reverse osmosis membrane cleaning
agent for on-line cleaning of the reverse osmosis membrane. The acidic cleaning
agent comprises of oxalic acid, hydrochloric acid, phosphoric acid, nitric acid and 1-
4% citric acid with pH 1-4. It also discloses conventional technology of using
chemicals for cleaning RO membrane.
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[0012] WIPO Patent publication WO1999055448A1 discloses a self contained water
purification process and system that uses a self cleaning, self sanitizing reverse
osmosis unit for reliably producing purified water, storing the water, and distributing
it to a central supply piping system while maintaining the integrity of the purified
water. Make-up water is prepared for reverse osmosis purification by means of staged
conventional filtration and chlorine removal. The prepared make-up water is then fed
into one or more reverse osmosis modules by a pump at a high velocity and pressure.
About 85 percent of the make-up water exits the module as purified water. All of the
water not passing through the reverse osmosis membranes returns to the suction end
of the pump where it blends with incoming make-up water except for a small portion
that is discharged to a waste drain. The high velocity flow maintains a shear effect
within the modules to prevent a sediment deposition and biofilm from occurring on
the membranes and increases the efficiency of water usage. However, the technology
is not efficient in controlling scales or performing automatic cleaning in the reject line
of water purifier.
[0013] US Patent publication US9707520B2 discloses a composition for treating a
water system or membrane fluid system, such as a reverse osmosis system, to remove
scale, microorganisms and biofilm, and corrosion by-products. The composition
comprises chelating agents and a surfactant. The publication explains the use of
chelating agents and surfactants to remove biofilm and microbial growth. This is a
whole system flushing process in treatment cycle or alternative cycle. This method is
practically not relevant in domestic RO system because dosing chelating agent and
surfactant in pre- RO filtration requires heavy control system to check the cleaning
agent not coming into permeate line and also ensuring this type of technology needs
additional cost for control device.
[0014] US Patent publication US2020129927A1 provides a water purification
apparatus capable of being cleaned at a point of care, and methods for cleaning the
water purification apparatus at the point of care. The water purification apparatus and
the methods provide an efficient use of a heater for heat disinfection the water
purification apparatus, e.g. by recirculating heated fluid to further heat the fluid.
Several different cleaning programs are provided that may be utilized for cleaning
different parts of the water purification apparatus. The publication discloses citric acid
cleaning of reject path of RO purifier system with pump and separate valve along with
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RO membrane cleaning. However, the process is complicated and practical industrial
use in domestic RO system is difficult and feasibility is under question.
[0015] IN 2434/CHE/2015 discloses de-scaling device which is based on the use of
citric acid as chemical agent for cleaning/de-scaling the water purifier. However, the
technology in this patent only talks about use of cleaning agent for cleaning of water
purifier and does not disclose automatic mechanism/system for cleaning of the reject
line based on real time and periodic sensing of the water characteristics like TDS,
flow sensor, photo sensor, pressure sensor etc.
[0016] The real time field problem of high recovery domestic RO system is flow
restrictor chocking and malfunction of flush solenoid valve before permeate flow drop
in RO membrane. The premature RO fouling due to Flow restrictor chocking is more
prevalent in domestic high recovery RO system than the conventional domestic RO
system. Most of the prior art fails to discuss high recovery RO system with 50-80% of
recovery. The existing technologies in the domain are not commercially relevant in
domestic RO system design and also involves significant service cost along with
leading to the wastage of precious water in domestic RO purifier sector. Hence, there
is needed a water purifier which is efficient in performing the cleaning of the reject
line without wasting any water for cleaning and which does not affect the feed water
and permeate side by cleaning agent.
[0017] As evident from the above disclosed patent publications, most of the
technologies use acids as cleaning agent for water purifier. However, none of the prior
art addresses the problem of cleaning reject line of high recovery RO system.
Particularly, there is no purifier/ technology that can automatically perform cleaning
of the reject line based on real time and periodic sensing of the water characteristics
like TDS, flow sensor, photo sensor, pressure sensor etc. Further, none of the prior art
addresses the problem of premature RO fouling due to flow restrictor chocking and
repeated system failure due to reject line solenoid valve malfunction in domestic high
recovery RO water purifier. The prior arts only explain the RO membrane cleaning
and restoration of flux in commercial RO system, which is not commercially relevant
in domestic RO system design.
[0018] The present invention addresses the technical problem by providing a water
purification apparatus with the feature of automatic cleaning and scale controlling in
reject line of a domestic water purification apparatus by using a periodic, automatic,
intelligent, time/flow/pressure driven cleaning and scale controlling mechanism in
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reject line of a domestic water purification apparatus. The Invention also addresses
the need of a system that can prevent premature RO fouling due to flow restrictor
chocking and repeated system failure due to reject line solenoid valve malfunction in
domestic high recovery RO water purifier.
Objective of the Invention:
[0019] Primary object of the present invention is to overcome the drawback
associated with the prior systems and methods.
[0020] Yet another object of the present invention is to provide a water purifier with
automatic cleaning and scale controlling/ cleaning in reject line of a domestic water
purification apparatus.
[0021] Yet another object of the present invention is to provide an automatic,
Periodic, intelligent, real time/Pump running time/flow/pressure driven cleaning and
scale controlling/ scale cleaning system in reject line of a domestic water purification
apparatus.
[0022] Yet another object of the present invention is to provide a water purifier that
addresses the problem of premature RO fouling due to flow restrictor chocking and
repeated system failure due to reject line solenoid valve malfunction in domestic high
recovery RO water purifier.
[0023] Yet another object of the present invention is to provide RO membrane
cleaning for restoration of flux.
[0024] Yet another object of the present invention is to provide Flow restrictor &
solenoid valve cleaning.
[0025] Yet another object of the present invention is to monitor RO membrane flux
drop due to flow restrictor chocking.
[0026] Yet another object of the present invention is to monitor premature RO
membrane fouling due to flow restrictor chocking.
[0027] Yet another object of the present invention is to monitor reject solenoid valve
failure due to calcium carbonate deposition and overall system failure due to solenoid
valve failure.
[0028] Yet another object of the present invention is prevention of flow restrictor
scaling to get maximum RO membrane performance as per feed water condition.
[0029] Yet another object of the present invention is feed water pH correction for
scale control.
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[0030] Yet another object of the present invention is to provide a method of operation
of the manual, automatic or photo sensor operated cleaning methods for hassle free
operation and not stopping the system in active water producing hours.
[0031] Yet another object of the present invention is to provide a method of automatic
cleaning and scale controlling/cleaning of reject line by the water purifier as described
above.
Summary of the Invention:
[0032] In an aspect, the Invention provides a water purifier with an automatic
cleaning and scale controlling/cleaning of reject line, comprising following
components:
a) atleast a reverse osmosis unit for filtering/ purifying water received from an inlet pipe
to produce atleast a purified water flowing through a permeate outlet and a reject
water flowing through a reject line;
characterised by:
b) atleast a first sensor positioned pre-RO membrane and a second sensor positioned
post-RO membrane for real time measurement of the parameters of the feed water and
the permeate water, wherein said sensors comprises flow sensor, photo sensor,
conductivity/TDS sensor, pressure sensor;
c) a control unit, based upon receiving at least one input from at least one of a sensor and
an input from periodic monitor/s comprising digital clock or pump running time
monitor, determines and activates dosing operator to perform dosing by consequently
releasing a cleaning agent from a cleaning agent chamber, positioned in the reject
line, if the value of the parameters ranges as following:
i) Reject flow rate of the water sensed by atleast a flow sensor is beyond 20 to 600
ml/min; and/or
ii) Cloudiness or turbidity of the water sensed by atleast a Photo Sensor is greater
than 0.5 NTU; and/or
iii) TDS of the water sensed by atleast a Conductivity/TDS sensor is beyond 50–
6000 ppm; and/or
iv) Pump pressure sensed by atleast a pressure monitor is beyond 65- 115psi;
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wherein the dosing operator adapted to work in conjugation with the cleaning
agent chamber is positioned in reject line before the flow restrictor and a reject
solenoid valve which are disposed parallel to each other on the reject line.
[0033] In another aspect, the Invention provides a method of automatic cleaning and
scale controlling/cleaning of reject line by the water purifier as described above,
comprising following steps:
a. Real-time and periodic monitoring of the feed inlet water, the permeate
outlet water, and the reject line water for parameters comprising reject
flow rate, cloudiness or turbidity, TDS, pump pressure, wherein said
real-time monitoring is performed through first and second sensor
comprising flow sensor, photo sensor, conductivity/TDS sensor,
pressure sensor while said periodic monitoring is performed by digital
clock and/or pump running time;
b. Receiving at least one input from at least one of a sensor and an input
from periodic monitor from step (a) by the control unit, positioned in the
reject line, for activating the dosing operator to perform dosing by
consequently releasing a cleaning agent from a cleaning agent chamber,
if the value of the parameters ranges as following:
i) Reject flow rate of the water sensed by atleast a flow sensor is beyond
20 to 600 ml/min; and/or
ii) Cloudiness or turbidity of the water sensed by atleast a Photo Sensor
is beyond >0.5 NTU; and/or
iii) TDS of the water sensed by atleast a Conductivity/TDS sensor is
beyond 50– 6000 ppm; and/or
iv) Pump pressure sensed by atleast a pressure monitor is beyond 65-
115psi.
Detailed Description of Drawing:
[0034] The foregoing detailed description of preferred embodiments are better
understood when read in conjunction with the appended drawings. For the purpose of
illustrating the invention, there is shown in the drawings exemplary constructions of
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the invention; however, the invention is not limited to the specific methods and
system disclosed. In the drawings:
[0035] Figure 1 illustrates a schematic view of an Automatic reverse osmosis (RO)
cleaning and scale controlling system in accordance to an embodiment of the present
disclosure.
[0036] Figure 2 illustrates an embodiment of the present invention showing reject
line, solenoid valve, cleaning agent chamber
[0037] Figure 3 illustrates another embodiment of the present invention showing
connection of dosing pump, reject and permeate line
[0038] Figure 4a illustrates a graphical representation reflecting Permeate flow vs.
Total permeate volume for a reverse osmosis unit with and without the system
[0039] Figure 4b illustrates a graphical representation reflecting Reject flow vs. Total
permeate volume for a reverse osmosis unit with and without the system.
Detailed Description of Invention:
[0040] Some embodiments of this invention, illustrating all its features, will now be
discussed in detail.
[0041] The words "comprising," "having," "containing," and "including," and other
forms thereof, are intended to be equivalent in meaning and be open ended in that an
item or items following any one of these words is not meant to be an exhaustive
listing of such item or items or meant to be limited to only the listed item or items.
[0042] It must also be noted that as used herein and in the appended claims, the
singular forms "a," "an," and "the" include plural references unless the context clearly
dictates otherwise. Although any systems and methods similar or equivalent to those
described herein can be used in the practice or testing of embodiments of the present
invention, the preferred, systems and methods are now described.
[0043] The disclosed embodiments are merely exemplary of the invention, which
may be embodied in various forms.
[0044] The elements illustrated in the Figures inter-operate as explained in more
detail below. Before setting forth the detailed explanation, however, it is noted that all
of the discussion below, regardless of the particular implementation being described,
is exemplary in nature, rather than limiting.
[0045] The invention relates to a water purifier/purification apparatus with automatic
reject line, RO & pre-RO cleaning and scale controlling system and method. More
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particularly, the invention provides water purifier with automatic cleaning and scale
controlling/prevention mechanism, present in reject line, based on a periodic,
automatic, intelligent, time/flow/pressure driven cleaning and scale controlling
system.
[0046] The system and method provided by the present invention is highly efficient,
simple and facilitates cleaning of flow restrictor and flush solenoid valve periodically
or automatically without affecting permeate water production. The invention also
addresses the problem of premature RO fouling due to flow restrictor chocking and
repeated system failure due to reject line solenoid valve malfunction in domestic high
recovery RO water purifier.
[0047] In an embodiment, the Invention provides an automatic reverse osmosis (RO)
system cleaning and scale controlling system comprising following components:
a) a reverse osmosis unit arranged to produce a purified fluid flow and a reject fluid
flow, the reverse osmosis unit including a feed inlet, a permeate outlet, and a reject
line;
b) a flow restrictor (FR) provided on the reject line;
c) a reject solenoid valve (RSV) provided on the reject line;
d) a cleaning agent chamber holding at least one cleaning agent, the chamber is
configured for supplying the cleaning agent to the reject line;
e) a dosing operator coupled to the cleaning agent chamber, the dosing operator being
configured to supply a dose of the cleaning agent to the reject line; and
f) a control unit operatively coupled to the dosing operator and the cleaning agent
chamber, the control unit being configured to operate the dosing operator to supply a
specific dose of the cleaning agent based upon real-time or pump running time or flow
or pressure monitoring of the feed inlet, the permeate outlet, and the reject line by the
control unit.
[0048] In an embodiment, the water purifier with an automatic cleaning and scale
controlling/cleaning of reject line, comprises following components:
a) atleast a reverse osmosis unit for filtering/ purifying water received from an inlet
pipe to produce atleast a purified water flowing through a permeate outlet and a
reject water flowing through a reject line;
characterised by:
b) atleast a first sensor positioned pre-RO membrane and a second sensor positioned
post-RO membrane for real time measurement of the parameters of the feed water
12
and the permeate water, wherein said sensors comprises flow sensor, photo sensor,
conductivity/TDS sensor, pressure sensor;
c) a control unit, based upon receiving at least one input from at least one of a sensor
and an input from periodic monitor/s comprising digital clock or pump running
time monitor, determines and activates dosing operator to perform dosing by
consequently releasing a cleaning agent from a cleaning agent chamber,
positioned in the reject line, if the value of the parameters ranges as following:
i) Reject flow rate of the water sensed by atleast a flow sensor /indirect way of
measuring the flow is beyond 20 to 600 ml/min; and/or
ii) Cloudiness or turbidity of the water sensed by atleast a Photo Sensor is greater
than 0.5 NTU; and/or
iii) TDS of the water sensed by atleast a Conductivity/TDS sensor is beyond 50–
6000 ppm; and/or
iv) Pump pressure sensed by atleast a pressure monitor is beyond 65- 115psi;
wherein the dosing operator adapted to work in conjugation with the cleaning
agent chamber is positioned in reject line before the flow restrictor and a reject
solenoid valve which are disposed parallel to each other on the reject line.
[0049] The system effectively provides solution for flow restrictor chocking of
domestic RO system, reject solenoid valve malfunction due to scale deposition, hassle
free cleaning time with photo sensor without affecting the active water producing
hours, preventing premature RO membrane fouling for domestic RO system and
domestic high recovery RO system, preventing premature RO fouling by correcting
feed water pH, providing maximum RO purifier life and preventing premature RO
fouling, chocking and malfunction of pre RO filters and water purifier parts.
[0050] In an embodiment, system can function with either or combination of the first
sensor positioned pre-RO membrane and the second sensor positioned post-RO
membrane. If it is in combination, there is a correlation. The rejection rate can be
calculated by measuring Feed water TDS/Conductivity & Permeate water TDS/
Conductivity. The range of rejection percentage is 50% – 95%. Any point of time the
specified rejection rate varies from 50% – 95%, the dosing will start.
[0051] In an embodiment, the water purifier comprises flow sensor, photo sensor,
conductivity/TDS sensor, pressure sensor. However, it is possible to have additional
sensors or have different sensors from those described in the present application.
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[0052] In an embodiment, the sensor also comprises an Optic/UV Sensor, which is
activated upon receiving signal/s from atleast 1 other sensor, for sensing the light &/or
UV source, wherein the control unit activates dosing if there is no visible light & UV
rays for 4 – 5 hrs.
[0053] In an embodiment, the digital time based clock operates at 24- 240 hrs or as
customised by a user.
[0054] In an embodiment, the sensors can work independently or in combination, to
sense the parameters of the water in the RO and sends the data to control unit which
determines and activates the dosing operator to consequently release a cleaning agent
from a cleaning agent chamber, positioned in the reject line.
[0055] In an embodiment, the control unit is configured for periodically monitoring
the reverse osmosis unit for evaluating parameters of the feed inlet, the permeate
outlet, and the reject line. The control unit operates based upon at least one input from
at least one of a sensor and digital time based clock.
[0056] In an embodiment, the parameters comprises permeate production, fluid flow
across reject line, scaling and deposition.
[0057] In an embodiment, the system comprises a non-returning valve (NRV).
[0058] In an embodiment, the cleaning agent comprises inorganic acid selected from
sulphamic acid, phosphoric acid or combination thereof. The characteristics of the
cleaning agent comprises include volume, type, pH, grade, time of dose, etc. of the
cleaning agent. This is decided based on the real-time or pump running time or flow
or pressure monitoring and the periodic monitoring.
[0059] In an embodiment, the cleaning agent is liquid and/or powdered and/or
crystalline and/or gel and/or solid.
[0060] In an embodiment, the volume of cleaning agent comprises 0.1-100 ml.
[0061] In an embodiment, the dosing operator will dose for 1- 20 min per dosing
cycle.
[0062] The present Invention has been described with reference to Inorganic acid as a
cleaning agent, however the system and method described herein can be implemented
by using other cleaning agents as well.
[0063] In an embodiment, the automatic reverse osmosis (RO) cleaning and scale
controlling method comprises following steps:
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a. Real-time and periodic monitoring of a reverse osmosis unit arranged to
produce a purified fluid flow and a reject fluid flow, the reverse osmosis
unit including a feed inlet, a permeate outlet, and a reject line;
b. providing at least one input from at least one of a sensor and digital time
based clock to a control unit based upon the monitoring;
c. operating a dosing operator by the control unit based upon the at least
one input; and
d. supplying a specific dose of at least one cleaning agent from a cleaning
agent chamber based upon operation of the dosing operator.
[0064] In an embodiment, the method of automatic cleaning and scale
controlling/cleaning of reject line by the water purifier as described above, comprises
following steps:
a. Real-time and periodic monitoring of the feed inlet water, the permeate
outlet water, and the reject line water for parameters comprising reject
flow rate, cloudiness or turbidity, TDS, pump pressure, wherein said
real-time monitoring is performed through first and second sensor
comprising flow sensor, photo sensor, conductivity/TDS sensor,
pressure sensor while said periodic monitoring is performed by digital
clock and/or pump running time;
b. Receiving at least one input from at least one of a sensor and an input
from periodic monitor from step (a) by the control unit, positioned in the
reject line, for activating the dosing operator to perform dosing by
consequently releasing a cleaning agent from a cleaning agent chamber,
if the value of the parameters ranges as following:
i) Reject flow rate of the water sensed by atleast a flow sensor is beyond
20 to 600 ml/min; and/or
ii) Cloudiness or turbidity of the water sensed by atleast a Photo Sensor
is beyond >0.5 NTU; and/or
iii) TDS of the water sensed by atleast a Conductivity/TDS sensor is
beyond 50– 6000 ppm; and/or
iv) Pump pressure sensed by atleast a pressure monitor is beyond 65-
115psi.
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[0065] In an embodiment, the method includes real-time and periodic monitoring of
a reverse osmosis unit arranged to produce a purified fluid flow and a reject fluid
flow, the reverse osmosis unit including a feed inlet, a permeate outlet, and a reject
line.
[0066] In an embodiment, the method further includes providing at least one input
from at least one of a sensor and digital time based clock to a control unit based upon
the monitoring.
[0067] In an embodiment, the method further includes operating a dosing pump by
the control unit based upon the at least one input.
[0068] In an embodiment, the method further includes supplying a specific dose of at
least one cleaning agent from a cleaning agent chamber based upon operation of the
dosing pump.
[0069] In an embodiment, the dosing is activated upon real time monitoring of 1 to
10 days or pump running for 24- 240hrs or as customised by a user.
[0070] In an embodiment, the dosing mechanism is initiated by the above described
sensing mechanism of the sensors and/ or by real time or pump time monitor. This can
happen in combination also. The dosing will initiate on the real time monitoring of 1-
10 days or pump running time of 24- 240hrs. The dosing operation time can vary from
1 – 20 minutes and amount ranges from 0.1ml – 100 ml of cleaning agent. The
cleaning agent will flow through reject line in every dosing cycle.
[0071] In an embodiment, the pump running time is assessed on real time basis. This can
be calculated in days or hours ranging from 1 - 10 days or 24 - 240 hours which will
in turn trigger the dosing cycle.
[0072] In an embodiment, the pressure is monitored on the basis of pump pressure
which will normally work at 65- 115psi. However, any deviation from this pressure
range will trigger the dosing cycle.
[0073] Figure 1 illustrates a schematic view of an Automatic reverse osmosis (RO)
and scale controlling system (100) in accordance with an embodiment of the present
disclosure. In an embodiment, the system (100) includes a reverse osmosis unit
arranged to produce a purified fluid flow and a reject fluid flow, the reverse osmosis
unit including a feed inlet, a permeate outlet, and a reject line. The system (100)
further includes a flow restrictor (FR) and a reject solenoid valve (RSV) provided on
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the reject line. In an embodiment, the flow restrictor and the reject solenoid valve are
disposed on parallel lines.
[0074] In an embodiment, the system (100) further includes a cleaning agent chamber
holding at least one cleaning agent. In an embodiment, the cleaning agent chamber
may be configured to hold only one cleaning agent. Alternatively, the cleaning agent
chamber may be designed to hold a plurality of cleaning agents such that a selective
cleaning approach may be utilized wherein a particular cleaning agent may be
selected for cleaning purposes based upon operational factors of the reverse osmosis
unit. In an embodiment, the chamber is configured for supplying the cleaning agent to
the reject line. Alternatively, the chamber may supply the cleaning agent to different
components of the reverse osmosis unit. In an example, the cleaning agent comprises
of at least one inorganic acid or combination of inorganic acids, such as Sulphamic
acid, Phosphoric acid etc. wherein the acids is one of liquid, powdered, crystalline.
[0075] In an embodiment, the system (100) further includes a dosing operator coupled
to the cleaning agent chamber. In an embodiment, the dosing operator is configured to
supply a dose of the cleaning agent to the reject line. Alternatively, the dosing
operator may supply the dose of cleaning agent to different components of the reverse
osmosis unit.
[0076] In an embodiment, the system (100) further includes a control unit operatively
coupled to the dosing pump and the cleaning agent chamber. In an example, the
control unit may be a PCB module associated with a computing system. In an
embodiment, the system (100) further includes at least one of a sensor and digital time
based clock. In an example, the sensor may be a photo sensor. In an embodiment, the
control unit is configured for real-time and periodic monitoring of the reverse osmosis
unit, and is further configured to operate the dosing pump to supply a specific dose of
the cleaning agent based upon real-time and periodic monitoring of the feed inlet, the
permeate outlet, and the reject line by the control unit.
[0077] In an embodiment, the control unit is configured for evaluating parameters of
the feed inlet, the permeate outlet, and the reject line of the reverse osmosis unit based
upon the real-time monitoring and the periodic monitoring. In an example, the
parameters includes one of permeate production, fluid flow across reject line, scaling,
and deposition. In an embodiment, characteristics of the specific dose of the cleaning
agent are based upon the real-time monitoring and the periodic monitoring, and in
17
turn the evaluated parameters discussed above. In an example, the characteristics
include volume, type, pH, grade, time of dose, etc. of the cleaning agent.
[0078] In an embodiment, the control unit operates based upon at least one input from
at least one of a sensor and digital time based clock. The cleaning cycle may trigger
with a photo/optic/UV sensor or digital time based clock. The UV photo sensor will
sense the presence of light and trigger the cleaning cycle in normal sleeping time. If
the sunset is around 6pm everyday and normal kitchen hours will be completed by
11pm, the cleaning cycle will trigger if the minimum light detected for 3 hrs. The
cleaning cycle may trigger periodically and automatically after every specific volume
of permeate production by the RO unit.
[0079] In an embodiment, periodic cleaning of the reject line will keep the flow
restrictor and solenoid valve free from calcium/magnesium carbonate and
inorganic/organic deposits and will maintain the defined concentrate water flow
throughout the life cycle. The deposit free solenoid valve will work systematically
throughout the life of the system and overcome the problem of system failure. The
RO membrane will give the maximum efficiency as per the feed water quality.
[0080] Figure 2 illustrates a schematic view of another Automatic reverse osmosis
(RO) cleaning and scale controlling system (200) in accordance with an embodiment
of the present disclosure. In this embodiment, the cleaning agent chamber includes
RO membrane of the reverse osmosis unit.
[0081] Figure 3 illustrates a schematic view of another Automatic reverse osmosis
(RO) cleaning and scale controlling system (300) in accordance with an embodiment
of the present disclosure. In this embodiment, the system (300) is configured for
automatic and periodic cleaning of RO membrane and pre RO filters with acid
solutions. A dosing operator connected to a different line from the same/different acid
chamber and connected before Pre – filter. The dosing pump will dose specific acid
solution to the said line while unit is on and/or defined pump running time and will
maintain the feed water pH 5.5-6.5. The lower pH will lower the feed water scaling
tendency (PSI and LSI) and will protect RO membrane and Pre RO filtration for
premature scaling.
The Invention is further described with the help of non-limiting examples:
18
Example 1:
The water in the purifier was tested by following sensors of the water purifier system:
a) Flow Sensor: It is an indirect way of flow monitoring. The flow monitoring depends
on the flow controller or flow restrictor used. The suitable range of reject flow rate
has to be 20 to 600 ml/min depending on the flow restrictor/controller used. In any
point of time if the reject flow decreases the specified flow, dosing will start.
b) Photo Sensor: Photo sensor will sense the cloudiness or turbidity of the water. If the
turbidity is >0.5 NTU, the dosing will start.
c) Conductivity/TDS sensor: The suitable range of TDS is 50– 6000 ppm & if any point
of time, the TDS increases or decreases from the specified value, the dosing will start.
d) Optic/UV Sensor: This sensor is indirectly connected and dependent on atleast 1 other
sensor for initiating the dosing. UV & Optic sensor will sense the light and start
dosing if there is no visible light & UV rays for 4 – 5 hrs as this is the indication of
sleeping time in the night. Optic/UV sensor can only start dosing if any of the other
sensor can give signal for dosing.
All the above mentioned sensors can be operated individually or in combination as per the
mode of usage and requirement.
Example 2:
A study was conducted with RO based water purifier having a Pre -RO Filters, RO Filters &
Post RO Filters with Automatic scale control/cleaning of reject line by the system of present
invention in comparison with a RO based water purifier without automatic scale
control/cleaning of reject line.
The feed water was selected with extreme scaling tendency in PSI scale and further the life of
the RO remembrance &/or overall system performance was tested. This study revealed that,
the flow restrictor of the system without automatic cleaning of reject line chocked in 706L of
permeate production and at the same time leads to premature RO membrane chocking & flux
drop. On the contrary, the system running with automatic cleaning of reject line passed ~
4000L of permeate water production without flow restrictor chocking & permeate flow &
flux drop also gradual as per the feed water condition.
19
System Configuration
Test Unit Filtration system Automatic reject line cleaning
Test Unit Pre RO, RO & Post RO
filtration
Yes
Control
Unit
Pre RO, RO & Post RO
filtration
No
Feed Water Condition
Parameters Values
TDS (ppm) 1000 - 2000
pH 7.0 – 8.5
Turbidity (NTU) <1
Total Hardness as CaCO3 (ppm) 800 - 1500
Calcium Hardness as CaCO3
(ppm)
700 - 1200
Total Alkalinity as CaCO3 (ppm) 600 - 700
Temperature (oC) 20 - 40
PSI Index Extremely severe scaling
Detailed Report
Feed
Pressu
re (psi)
Total
Permeate
(L)
Permeate
Flow
(ml/min)
Reject Flow
(ml/min)
Permeate
TDS (ppm)
Recovery% Rejection%
Test
Unit
Contr
ol
Test
Unit
Cont
rol
Test
Unit
Contr
ol
Test
Unit
Cont
rol
Te
st
Un
it
Contr
ol
Test
Unit
Contr
ol
15 12 12 200 205 65 70 125 145 75 75 94 93
15 120 123 200 205 65 70 129 134 75 75 94 94
15 180 185 200 205 65 70 138 131 75 75 94 94
15 312 320 200 20 65 950 131 202 75 2 94 90
15 456 464 200 200 65 55 126 128 75 78 94 94
15 610 561 190 115 65 25 120 135 75 64 94 94
15 848 706 180 75 65 785 123 195 73 9 94 91
Control Unit Terminated
15 1034 0 170 0 65 0 127 0 72 0 95 0
15 1248 0 170 0 65 0 138 0 72 0 95 0
15 1608 0 165 0 65 0 138 0 72 0 95 0
15 1964 0 165 0 65 0 141 0 72 0 95 0
20
15 2222 0 165 0 65 0 129 0 72 0 95 0
15 2341 0 165 0 65 0 131 0 72 0 95 0
15 2578 0 165 0 65 0 113 0 72 0 96 0
15 2741 0 160 0 65 0 126 0 71 0 94 0
15 2979 0 150 0 65 0 119 0 70 0 95 0
15 3227 0 140 0 65 0 136 0 68 0 93 0
15 3336 0 140 0 65 0 148 0 68 0 93 0
15 3430 0 130 0 65 0 161 0 67 0 92 0
15 3508 0 130 0 65 0 165 0 67 0 92 0
15 3716 0 120 0 65 0 178 0 65 0 91 0
Test Unit Terminated
• Values in red due to malfunction of solenoid valve
Summary of the Test Data
Unit
Total
Permeate
Volume (L)
Permeate Flow
(ml/min)
Reject Flow
(ml/min)
Permeate TDS
(ppm)
Reject TDS (ppm)
Min Max Min Max Min Max Min Max
Test Unit 3720 120 200 65 65 110 178 4370 6640
Control
Unit
706 115 205 25 70 126 186 5460 7250
Recovery% & Rejection% Summary
Unit
Total Permeate
Volume (L)
Recovery % Rejection %
Beginning End Min Max
Test Unit 3720 75.5 65.0 91.0 96.0
Control 706 75.0 9.0 91.0 94.0
Solenoid valve performance
Unit Issue
Control Malfunction at 320L of permeate Production
Malfunction at 706L of permeate Production
Test Unit No malfunction observed
The test study on automatic and periodic cleaning of reject line demonstrates about the
efficiency of the system provided by the present invention, which is indispensable to achieve
21
expected high recovery with extended life in domistic RO purifiers. The test study further
demonstrates that the system can efficiently stop the flush solanoid valve malfunction issue
due to scale deposit. Figure 4a illustrates a graphical representation reflecting Permeate flow
vs. Total permeate volume for a reverse osmosis unit with and without the system while
Figure 4b illustrates a graphical representation reflecting Reject flow vs. Total permeate
volume for a reverse osmosis unit with and without the system. ,CLAIMS:We Claim:
1. A water purifier with an automatic cleaning and scale controlling/cleaning of reject
line, comprising:
a) atleast a reverse osmosis unit for filtering/ purifying water received from an inlet
pipe to produce atleast a purified water flowing through a permeate outlet and a
reject water flowing through a reject line;
characterised by:
b) atleast a first sensor positioned pre-RO membrane and a second sensor positioned
post-RO membrane for real time measurement of the parameters of the feed water
and the permeate water, wherein said sensors comprises flow sensor, photo sensor,
conductivity/TDS sensor, pressure sensor;
c) a control unit, based upon receiving at least one input from at least one of a sensor
and an input from periodic monitor/s comprising digital clock or pump running
time monitor, determines and activates dosing operator to perform dosing by
consequently releasing a cleaning agent from a cleaning agent chamber,
positioned in the reject line, if the value of the parameters ranges as following:
i) Reject flow rate of the water sensed by atleast a flow sensor is beyond 20 to 600
ml/min; and/or
ii) Cloudiness or turbidity of the water sensed by atleast a Photo Sensor is greater
than 0.5 NTU; and/or
iii) TDS of the water sensed by atleast a Conductivity/TDS sensor is beyond 50–
6000 ppm; and/or
iv) Pump pressure sensed by atleast a pressure monitor is beyond 65- 115psi;
wherein the dosing operator adapted to work in conjugation with the cleaning
agent chamber is positioned in reject line before the flow restrictor and a reject
solenoid valve which are disposed parallel to each other on the reject line.
2. The water purifier as claimed in claim 1, wherein cleaning agent comprises inorganic
acid selected from sulphamic acid, phosphoric acid or combination thereof.
3. The water purifier as claimed in claim 1, wherein said sensor further comprises
Optic/UV Sensor, activated upon receiving signal/s from atleast 1 other sensor, for
23
sensing the light &/or UV source, wherein the control unit activates dosing if there is
no visible light & UV rays for 4 – 5 hrs.
4. The water purifier as claimed in claim 1, wherein cleaning agent is liquid and/or
powdered and/or crystalline and/or gel and/or solid.
5. The water purifier as claimed in claim 1, wherein said digital time based clock
operates at 24- 240hrs or as customised by a user.
6. The water purifier as claimed in claim 1, wherein the dosing mechanism is activated if
the rejection percentage determined by said first sensor and second sensor is beyond
50- 95%.
7. The water purifier as claimed in claim 1, wherein the volume of cleaning agent
comprises 0.1-100 ml.
8. The water purifier as claimed in claim 1, wherein the dosing operator will dose for 1-
20 min per dosing cycle.
9. A method of automatic cleaning and scale controlling/cleaning of reject line by the
water purifier as claimed in claim 1, comprising following steps:
a. Real-time and periodic monitoring of the feed inlet water, the permeate
outlet water, and the reject line water for parameters comprising reject
flow rate, cloudiness or turbidity, TDS, pump pressure, wherein said
real-time monitoring is performed through first and second sensor
comprising flow sensor, photo sensor, conductivity/TDS sensor,
pressure sensor while said periodic monitoring is performed by digital
clock and/or pump running time;
b. Receiving at least one input from at least one of a sensor and an input
from periodic monitor from step (a) by the control unit, positioned in the
reject line, for activating the dosing operator to perform dosing by
consequently releasing a cleaning agent from a cleaning agent chamber,
if the value of the parameters ranges as following:
i) Reject flow rate of the water sensed by atleast a flow sensor is beyond
20 to 600 ml/min; and/or
24
ii) Cloudiness or turbidity of the water sensed by atleast a Photo Sensor
is beyond >0.5 NTU; and/or
iii) TDS of the water sensed by atleast a Conductivity/TDS sensor is
beyond 50– 6000 ppm; and/or
iv) Pump pressure sensed by atleast a pressure monitor is beyond 65-
115psi.
10. The method as claimed in claim 9, wherein the dosing is activated upon real
time monitoring of 1 to 10 days or pump running for 24- 240hrs or as customised by a
user.