DESC:Technical Field
The present disclosure relates to water saving systems. In particular, the present disclosure provides a waste water reuse system for Reverse Osmosis membrane water purifiers.

Background
The use of reverse osmosis (RO) membrane in water purifiers is known in the art. RO membrane water purifiers, hereinafter referred to as RO purifiers, generally have a water inlet and two water outlets. The two water outlets include a pure water outlet and a waste water outlet. The waste water outlet purges the high concentration water that does not pass through the RO membrane. Conventionally, the waste water from RO water purifiers is not used and is wasted in drainage.
Various waste water recycling systems are known in the art. The Chinese Patent Document CN201121144Y discloses a water recycling system for a RO Filter. In this document, the reject water from the RO membrane is directed towards a pressurized tank through a solenoid valve and a pressure release valve. From the pressurized tank, the water flows towards the outlet. The pressurize tank has a complex construction in which the tank is divided by a diaphragm into two portions for storing the fresh water and reject water, and a special valve is provided on the diaphragm that mixes the source water with reject water. Such a system is complex in construction, bulky and costly to deploy.
The present disclosure is directed to address one or more problems as discussed above and other problems associated with the art.
Summary
A waste water reuse system, hereinafter referred to as a system, for an RO water filter is disclosed. The system has a normal water source for supply of normal water and an RO (reverse osmosis) filter connected with the normal water source. The RO filter is configured to dispense waste water through a waste water outlet and pure water through a pure water outlet. A high pressure tank is fluidly connected with the waste water outlet of the RO filter for receiving and collecting the waste water from the RO water filter. A mixer tap is connected with the normal water source, the high pressure tank and the pure water outlet. The mixer tap is configured for supply of any one of pure water, normal water, waste water, and mixture of waste water and normal water.
In an embodiment, the mixer tap is configured for selectively mixing the waste water and normal water in variable ratio.
Yet in an embodiment, the system has a drain circuit for draining out excess waste water from the system. The drain circuit has a drain line having a drain inlet connected to the waste water line and a drain outlet for draining out the waste water from the waste water line. A solenoid valve is positioned on the drain outlet to regulate flow of waste water through the drain outlet by opening or closing of the solenoid valve. A high pressure switch is coupled with the drain line for sensing a pressure value in the waste water line and actuating the solenoid valve for opening or closing of the solenoid valve based on the pressure value in the waste water line.
In an embodiment, the solenoid valve opens when the pressure value reaches above a second predetermined pressure value threshold and closes when the pressure value falls below a first predetermined threshold.
In an embodiment, the high pressure switch has a pressure sensing element, and a connector coupled with the pressure sensing element. The pressure sensing element actuates the connector to open or close the drain circuit.
In an embodiment, the mixer tap has a pure water inlet for receiving pure water, a normal water inlet connected with the normal water source for receiving the normal water, a waste water inlet connected with the waste water line for receiving the waste water, a mixed water outlet for dispensing normal water or waste water or a mixture thereof, and a pure water outlet for dispensing pure water.
In an aspect, the mixer tap is configured to mix the normal water and waste water in selectively variable proportions.
In an aspect, the first predetermined threshold and the second predetermined threshold may be configured to drain 1000-1400 ml of water once the solenoid valve opens.
Yet in an embodiment, the first predetermined threshold and the second predetermined threshold may be configured to drain an amount of water equivalent to 10-20% of the capacity of the high pressure tank.
In an embodiment, the pressure sensing element may be a diaphragm.
Brief Description of Drawings
FIG. 1 illustrates a schematic view of a waste water reuse system in accordance with an embodiment of the present disclosure.
FIG. 2 illustrates a circuit diagram of a High Pressure Switch used in the waste water reuse system in accordance with an embodiment of the present disclosure.
Description
The present disclosure provides a waste water reuse system (100), hereinafter referred to as the ‘system’, for RO purifiers. RO water purifiers use a reverse osmosis membrane to filter water. A pump is used to pressurize water against the RO membrane. A portion of water passes through the RO membrane, whereas the remaining portion is routed outside the purifier as a waste water with high concentration of total dissolved solids. The waste water reuse system (100) is adapted for the reuse oleof water purged from the RO purifiers as waste water or concentrated water.
Referring to FIG. 1, a waste water reuse system (100), or in other words a system (100) for reuse or recycle of waste water is shown. The waste water reuse system (100) is referred to as the system (100) hereinafter.
The system (100) has a RO purifier (102), also referred to as RO filter (102), that is connected to a normal water source (104). The normal water source (104) may be the general tap water that is supplied for domestic or industrial use. The RO purifier (102) receives the normal water and provides a stream of pure water and a stream of waste water. The pure water can be taken out from the RO purifier (102) by the pure water line (106) of the RO purifier (102). The waste from the RO purifier (102) is directed towards a high pressure tank (110) via a waste water line (108). The high pressure tank (110) stores the waste water in a pressurized condition. The pressure of water coming out from the RO purifier (102) may be greater than the pressure in the high pressure tank (110) so that water from the waste water outlet of the RO purifier (102) gets accumulated in the high pressure tank (110) without requiring any additional pump.
As shown in FIG. 1, a non-return valve (112) may be positioned in the waste water line (108) just downstream of the waste water outlet of the RO purifier (102). The non-return valve (112) may prevent the back-flow of waste water from high pressure tank (110) to the RO purifier (102). The non-return valve (112) may also prevent the back pressure on the RO membrane of the RO purifier (102). The high pressure tank (110) may be positioned downstream of the non-return valve (112).
The high pressure tank (110) is fluidly connected to a mixer tap (140). The mixer tap (140) may be a tap that has three inlets and two outlets. The mixer tap (140) may have a waste water inlet (114) connected to the high pressure tank (110) to receive waste water from the RO Purifier (102). The mixer tap (140) may further have a normal water inlet (116) connected to the normal water source (104) to receive the normal water. The mixer tap (140) may have a pure water inlet (118) connected to the pure water line (106) of the RO filter (102) to receive pure water. The mixer tap (140) may be configured to selectively mix the water received from the normal water source (104) and the waste water line (108) and provide a single outlet stream through a mixed water outlet (120). The mixer tap (140) may be configured for mixing the normal water and waste water in variable ratios or proportions as required. Further, the mixer tap (140) may have a pure water outlet for delivery of pure water received from the RO filter (102).
The mixer tap (140) may have a first knob that may be configured to selectively mix and draw out the normal water and waste water through the mixed water outlet (120). Accordingly, the mixer tap (140) may be used to selectively draw out waste water, a mix of waste water and normal water, and normal water. When a user opens the mixer tap (140) to draw out waste water, the waste water accumulated in the high pressure tank (110) may be drawn out.
The mixer tap (140) may have a separate pure water outlet fluidly connected to the pure water inlet (118) for drawing out pure water. The pure water outlet in the mixer tap (140) may be configured with a separate knob for opening or closing the pure water outlet. The configuration of the mixed water outlet (120) and the pure water outlet may be such that the water from the mixed water outlet (120) does not contact with water in the pure water outlet at any instance. Thus, contamination of pure water may be avoided altogether, while providing a single mixer tap (140) for drawing out four types of water, i.e. normal water, waste water, a mix of normal water and waste water, and pure water.
As the RO purifier (102) purifies water, waste water is generated and pumped through the waste water line (108) for storage in the high pressure tank (110). By use of the mixer tap (140), the waste water from the high pressure tank (110) may be drawn out. However, due to non-use of the waste water over a period of time, the high pressure tank (110) may get completely filled over time and there may be no room for accumulation of more waste water in the high pressure tank (110). In such a scenario, the pressure in the waste water line (108) may increase undesirably, which may lead to damage to the waste water line (108), or other components of the system (100), or other hazardous situation. Accordingly, a drain line (122) is provided in the system (100) for releasing waste water from the high pressure tank (110) when the high pressure tank (110) is full.
The drain line (122) has a drain inlet (124) at one end that is connected to the waste water line (108) to receive the waste water from the waste water line (108), and a drain outlet (126) at the other end for purging out waste water out of the system (100). The drain line (122) has a high pressure switch (128), and a solenoid valve (130) positioned downstream of the high pressure switch (128) at the drain outlet (126). The solenoid valve (130) is configured to selectively open and close the drain outlet (126) of the drain line (122) as disclosed herein.
The drain outlet (126) of the drain line (122) may open for purging out waste water when the solenoid valve (130) opens. The high pressure switch (128) senses pressure value in the waste water line (108). When the pressure value in the waste water line (108) crosses above a first predetermined pressure threshold, the high pressure switch (128) closes an electric/electronic circuit to open the solenoid valve (130). Thus, the solenoid valve (130) may be opened for releasing or draining out waste water to normalize the pressure in the waste water line (108). In the embodiment as illustrated, the high pressure switch (128) is shown electrically coupled with the solenoid valve (130).
FIG. 2 illustrates a schematic circuit diagram (referred to as ‘drain circuit’)of connections that couple the high pressure switch (128) with the solenoid in accordance with an embodiment. The drain circuit (142) has a power source (132), a connector (134), a pressure sensing element (136) and a load (solenoid valve). The pressure sensing element (136), e.g. a diaphragm, is exposed to the pressure in the waste water line (108), such that the rise and fall in pressure value may actuate the pressure sensing element (136). Further, the connector (134), which closes or breaks the circuit upon actuation, is coupled with the pressure sensing element (136) such that the movement in the pressure sensing element (136) actuates the connector (134).
As shown in FIG. 2, the drain circuit (142) remains normally open, i.e. when the pressure in the waste water line (108) is below a first predetermined threshold, the pressure sensing element (136) may be in rest state and the circuit (142) of the high pressure switch (128) remains open. When the pressure in the waste water line (108) crosses above beyond a second predetermined threshold, the sensing element may actuate the connector (134) and the connector (134) may move and close the circuit (142) to supply current for actuation of the solenoid. Thus, closing of the circuit actuates the solenoid valve (130) to open the draining outlet for releasing waste water through the drain line (122). As the water gushes out from the high pressure tank (110), the pressure value in the waste water line (108) may drop. When the pressure value drops below the first predetermined threshold, the pressure sensing element (136) may move and thus actuate the connected to break the circuit (142). Breaking of the circuit may de-energize the solenoid valve (130) and thus the solenoid valve (130) may close the drain outlet (126). Thus, a mechanical high pressure switch (128) may be used the system (100) as disclosed herein.
The first predetermined threshold and the second predetermined threshold may be configured as suitable. The thresholds may be configured to ensure a predetermined amount of water flows out from the drain line (122) before the solenoid valve (130) closes. For example, if the high pressure tank (110) has a capacity of 8 litres, the first and second threshold may be configured to drain out 1000-1400 ml of water once the high pressure tank (110) gets full.
In an embodiment, the predetermined time, for which the solenoid valve (130) remains open, may be selectively set to release a predetermined amount of water from the high pressure tank (110). Thus, when the predetermined amount of water is released from the high pressure tank (110) the solenoid valve (130) automatically closes.
The predetermined amount of water may be selected such that the drain line (122) does not open frequently on frequent use of the RO purifier (102). A user of a domestic RO purifier (102) generally uses the RO purifier (102) frequently for drinking a glass of water or for cooking. If the predetermined amount is set very low, the waste water reuse system (100) may get activated frequently to release pressure in the waste water line (108). On the other hand, if the predetermined amount is selected very high, a lot of waste water may get drained unnecessarily. Refilling up of the high pressure tank (110) may take some time, which may lead to non-availability of sufficient waste water in the high pressure tank (110) for some time after draining of the waste water. Therefore, it is desirable to optimize the amount of water that gets drained on opening of the drain circuit so that the waste water reuse system (100) may not get activated very frequently, and simultaneously, unnecessary draining of water through the drain line (122) is prevented.
In an embodiment, the predetermined amount of water may be 10-20% of the storage capacity of the high pressure tank (110). In an embodiment, the predetermined amount may be a fixed amount of water irrespective of the storage capacity of the high pressure tank (110).
The system (100) as disclosed herein provides for the reuse of waste water generated from the RO purifiers. The system (100) as disclosed is convenient to use and operate. The system (100) provides the option for a consumer to use either waste water, normal water, or a mix of waste water and the normal water. The system (100) further incorporates a drain line (122) that purges out a predetermined amount of waste water to prevent frequent activation of the drain line (122), while ensuring the supply of the waste water at the mixer tap (140). The system (100) as disclosed herein may be built using a mechanically operated high pressure switch (128) to limit the overall costs and complexity of the system (100). The system (100) as disclosed prevents wastage of waste water from the RO purifiers.

Reference Numerals
System (100)
RO Purifier/Filter (102)
Normal Water Source (104)
Pure Water Line (106)
Waste Water Line (108)
High Pressure Tank (110)
Non-Return Valve (112)
Waste Water Inlet (114)
Normal Water Inlet (116)
Pure Water Inlet (118)
Mixed Water Outlet (120)
Drain Line (122)
Drain Inlet (124)
Drain Outlet (126)
High Pressure Switch (128)
Solenoid Valve (130)
Power Source (132)
Connector (134)
Pressure Sensing Element (136)
Mixer Tap (140)
Drain Circuit (142)
,CLAIMS:We claim:
1. A waste water reuse system (100) for an RO water filter (102), the system (100) comprising:
a normal water source (104) for supply of normal water;
an RO filter (102) connected with the normal water source (104), the RO filter (102) configured to dispense waste water through a waste water outlet and pure water through a pure water outlet;
a high pressure tank (110) fluidly connected with the waste water outlet of the RO filter (102) for receiving and collecting the waste water from the RO water filter (102);
a mixer tap (140) connected with the normal water source (104), the high pressure tank (110) and the pure water outlet, wherein the mixer tap (140) is configured for supply of any one of pure water, normal water, waste water, and mixture of waste water and normal water.

2. The system (100) as claimed in claim 1, wherein the mixer tap (140) is configured for selectively mixing the waste water and normal water in variable ratio.

3. The system (100) as claimed in claim 1, comprising a draining circuit for draining out excess waste water from the system (100), the draining circuit comprising:
a drain line (122) having a drain inlet (124) connected to the waste water line (108) and a drain outlet (126) for draining out the waste water from the waste water line (108);
a solenoid valve (130) positioned on the drain outlet (126) to regulate flow of waste water through the drain outlet (126) by opening or closing of the solenoid valve (130);
a high pressure switch (128) positioned upstream of the solenoid valve (130) and electrically coupled with the solenoid valve (130) for opening or closing of the solenoid valve (130) based on the pressure value in the waste water line (108).

4. The system (100) as claimed in claim 3, wherein the solenoid valve (130) opens when the pressure value reaches above a second predetermined threshold and closes after the pressure value crosses below a first predetermined threshold.

5. The system (100) as claimed in claim 1, wherein the high pressure switch (128) is a mechanically operated high pressure switch (128).

6. The system (100) as claimed in claim 5, wherein the high pressure switch (128) comprises:
a pressure sensing element (136); and
a connector (134) coupled with the pressure sensing element (136), the connector (134) configured to open or close an electrical circuit;
wherein the pressure sensing element (136) actuates the connector (134) based on a pressure value for opening or closing the electrical circuit.

7. The system (100) as claimed in claim 1, wherein the mixer tap (140) comprises:
a pure water inlet (118) connected with the RO purifier (102) for receiving pure water;
a normal water inlet (116) connected with the normal water source (104) for receiving the normal water;
a waste water inlet (114) connected with the waste water line (108) for receiving the waste water;
a mixed water outlet (120) for dispensing normal water or waste water or a mixture thereof; and
a pure water outlet for dispensing pure water.

8. The system (100) as claimed in claim 7, wherein the mixer tap (140) is configured to selectively mix the normal water and waste water in variable proportions.
9. The system (100) as claimed in claim 4, wherein the first predetermined threshold and the second predetermined threshold are configured to drain 1000-1400 ml of water once the solenoid valve (130) opens.

10. The system (100) as claimed in claim 4, wherein the first predetermined threshold and the second predetermined threshold are configured to drain an amount of water equivalent to 10-20% of the capacity of the high pressure tank (110).

11. The system (100) as claimed in claim 6, wherein the pressure sensing element (136) is a diaphragm.

Dated this 21st day of April 2023

GAURAV CHOUBEY
of PRIYA RAO & ASSOCIATES
Agent for the Applicant(s)
IN/PA/2369
Digitally signed & filed through e-filing