The present application is a cognate application of Patent Application No. 201911010085 and Patent Application No. 201911010086.
FIELD OF THE INVENTION:
[002] The present invention relates to a method and system for monitoring the filters in an RO water purifier. More particularly, the present invention relates to monitoring the actual status or performance of said filters thereby improving the overall performance and life of the RO water purifier.
BACKGROUND OF THE INVENTION:
[003] Water, being one of the basic necessities of life, is required in every sphere. Since, the water bodies are subjected to various pollutants; they become a source of numerous communicable and fatal diseases. Hence, purification of water is of vital importance. Such purification is performed by water purifiers employing the technique of Reverse Osmosis (RO). Water purifiers remove harmful contaminants from source water and provide pure water that is fit for drinking. The life of the water purifier depends upon various factors including the type of purifier being used such as RO/ UV / GRAVITY etc., quality of the product, quality of input water, regular maintenance, hours and volume of water used, etc.
[004] A filter installed in the water purifier filters the harmful contaminants present in the polluted water thereby making it fit for drinking purpose. Therefore, it is essential to maintain and timely change the filter. The most important part of any water purifier in the process of purification of water is RO membrane. The RO membrane reduces the TDS level up to 90% depending on the quality of RO membrane.

[005] The Life of a RO membrane depends on the TDS level of the input water and the usage of said RO membrane. If the input TDS level is high then the life of RO membrane would be less and if the input TDS level is less, then life of said RO membrane would be high. For instance, a water purifier is designed for maximum 2000 TDS then the RO membrane life for said input TDS will be less, whereas it would be good for an input TDS of 500. Hence, the life of the RO membrane doesn't depend on the time doesn't require to be replaced within fixed time period. Generally, other filters such as sediment filter, carbon filter etc. available in the product have a life of 6 to 12 months. Most of the water purifiers available in the market calculate the filter life measuring the pump running time.
[006] Such a method and system has been disclosed in FN2009CH00126A. Said invention relates to a water treatment system with electronic membrane life enhance to reduce the membrane failure due to scaling of salts on the surface of the membrane used for water treatment or purification. This consists of a electronic circuitry generate high frequency micro vibration and a wiring system to transmit this high frequency micro vibration to water to vibrate the scale forming molecules in to a disturbed stage.
[007] Such a method and system has been disclosed in DEI02010038928Al. Said invention relates to a Filter device (1) for a filtration system, preferably a water dispenser, for purifying water, comprises a housing (2) comprising a water inlet (4), a fresh water outlet (6), a wastewater outlet, an individualized set of filter elements with several filter elements, and a measuring device (12) for detecting and displaying performance-related measurement data, which considers a combination of the filter elements during the evaluation of measured data. An independent claim is also included for a filtration system, preferably a water dispenser, for purifying water, comprising the above filter device.
[008] Such a method and system has been disclosed in US5865991A. Said invention relates to a monitoring device for a drinking water purification system comprising a microprocessor that controls the overall operations of the monitoring system, a LCD indicating circuit that relates information to maintenance personnel, a detecting means

that analyses related data for determining the condition and extents of clogging of the filtration elements, a warning means that produces verbal or musical sound for warning consumers about the clogged condition of the water filtration elements, and a power switching means that cuts off electricity supply to the water pump of the purification system. In operation, the filtration elements will be clogged by impurities after being used for a period of time. If the filtration elements are clogged, the monitoring device will make a sound to warn of such condition of the filtration elements and will eventually cut off the power supply to the pump for stopping water delivery if the clogged filtration elements are not replaced after a certain period of time.
[009] Such a method and system has been disclosed in CN107649007. Said invention relates to a water purifier and a judgment method for a life of an RO (Reverse Osmosis) membrane filter element of a water purifier. The method comprises the steps of detecting current signals of a pre-positioned pressure pump of the RO membrane filter element, and comparing a detected value with a default, so as to obtain life information on the RO membrane filter element. The water purifier comprises the RO membrane filter element, wherein a pressure pump is arranged on a pipeline between the RO membrane filter element and a water inlet so as to supply water flow power to inlet water flowing in the RO membrane filter element, a current detecting device is arranged at a power input end of the pressure pump so as to detect the current signals of the pressure pump, the current detecting device is connected with a processor, and current signal detected values of the pressure pump are applied to the method so as to obtain the life information on the RO membrane filter element. According to the water purifier and the judgment method for the life of the RO membrane filter element of the water purifier, through detecting sizes of the current signals of the pressure pump, life conditions of the RO membrane filter element can be simply and accurately judged, tedious operating steps of the traditional filter element life judgment method are avoided, customer use is better facilitated, and user experience is improved.
[010] Such a method and system has been disclosed in KR20030062838A. Said invention

relates to a reverse osmosis pressure water dispenser capable of measuring water quality and flow rate is provided, which can replace filter at an optimum time based on the correctly calculated data of water quality of raw water and produced water and produced water flow, so that the system can prevent any advanced replacement of filter and any delayed replacement thus saving filter cost and preventing any contamination of water caused by delayed replacement. CONSTITUTION: In the reverse osmosis pressure water dispenser composed of settling filter, an automatic raw water blocking valve, a pump, a pre-carbon filter, a membrane filter, a post-carbon filter, comprised are a first TDS sensor(80) installed on pipe between the pre-carbon filter(40) and membrane filter(50) for detecting turbidity of raw water; a second TDS sensor(82) installed at the discharge line of the membrane filter(50) for detecting turbidity of filtered water; a flow meter(90) installed on the pipe between the membrane filter(50) and carbon filter(40) for detecting the flow of the filtered water; and a control unit(84) for receiving signals from the sensors and flow meter, computing filter replacing time and displaying the computed data of filter replacing time.
[Oil] The RO water purifiers as described in the prior art cannot provide complete transparency in the working of the purification system in the RO water purifier. Also, said RO water purifiers require high maintenance cost.
OBJECTS OF THE INVENTION:
[012] The objective of the present invention is to design a method and system for monitoring the actual status or performance of sediment filter, carbon filters and RO membrane thereby improving the overall performance and life of the RO water purifier.
[013] The instant invention achieves the objective by employing a method and system for monitoring different parts of the RO water purifier for the measurement of true life of the membrane filter based on the actual usage of said filters of said RO water purifier.

SUMMARY OF THE INVENTION:
[014] The present invention relates to a method and system for monitoring the filters in an RO water purifier. More particularly, the present invention relates to monitoring the actual status or performance of said filters thereby improving the overall performance and life of the RO water purifier.
[015] The basic structure of a purification system installed in an RO water purifier comprises of the components as depicted in Figure 1 and the basic life cycle of an RO membrane is depicted in Figure 2. Considering that the input water condition is same throughout the life cycle of said membrane, the RO water purifier provides with the following amount of water from the filters:
1. During the initial phase = X ml of water;
2. During the intermediate phase = Y ml of water; and
3. During the last phase = Z ml of water
[016] The amount of output water from the RO water purifier reduces as follows: Z < Y < X. Said decrease in the amount of output water is dependent on the TDS level of the input water. The decrease in the output water flow can be measured by various ways, including but not limited to, a flow sensor. Said technique does not provide the results with utmost certainty as the decrease in the flow rate of the output water can be attributed to various other reasons, such as non-availability of input water supply; choking of pre-filters (filters placed before RO membrane); breakage of the membrane filter as illustrated in Figure 3.
[017] The true and actual working and usage of the RO membrane is ascertained by considering and monitoring three parts of the RO water purifier: Low Pressure Switch (LPS); Pump; and Flow Sensor. The main purpose of the flow sensor is to measure the membrane output flow rate. The LPS is employed in the RO water purifier for the purpose of checking the availability of required amount of input water pressure. The Pump draws

the current and the value the same is used in the decision making. The current drawn by the pump is different in different circumstances. A unique kind of electronic circuit is design to measure this pump current. As described in Figure 4 of the instant invention, when the pump is working then current flows through shunt resistors. The voltage across the resistors is measured and said voltage is provided to the input of Op-amp 1. The output of the Op-ampl (OUT1) is given to input of Op-amp2. The output gain is increased using resistor R100 to get significant voltage level. The said voltage level is received by controller and it is compared with the current table mapped with different voltage level. Based on this, decision is made about pump running situation.
[018] The working of the RO membrane filter is perfect if said RO membrane provides:
1. Proper TDS reduction;
2. Proper output flow.
[019] The validation of the first condition as stated above requires the actual values of the input and output TDS levels of the water. Said TDS levels are measured with the aid of TDS sensors installed separately for input water and output water. The reduction of TDS level below 80% indicates that the RO membrane filter is not working efficiently and hence a replacement of said RO membrane filter is required.
[020] The validation of the second condition as stated above requires the ascertainment of exact reason for the reduction of the flow rate.
[021] The overall concept is depicted in Figure 3. The monitoring of the filters of the RO water purifiers is carried out only under the purification condition of the RO water purifier. During the purification process, if the flow rate of the RO membrane filter is below F ml/min (said parameter varies depending on the quality and manufacture of the RO membrane filter), then the exact reason for said flow rate is required to be determined by the following steps:

1. Confirm the availability of water supply to the RO water purifier that is indicated by no LPS state error.
2. Check the condition of the sediment filter by monitoring the current drawn by the pump. The current drawn by the pump is dependent on the amount of water passing through said pump. Greater the amount of water flowing through the pump, greater is the load on the pump and higher is the current drawn by the pump.
3. In case, the sediment filter is choked and the pump is not receiving water at the input then said pump works in the dry run state and the current drawn by the pump is x A. For greater accuracy, xl and x2 parameters are considered and if the current is measured between xl and x2, then the pump is running as dry indicating choking of the sediment filter. A different indication is provided for sediment chocking and the requirement for replacing the sediment filter.
4. If the sediment filter is not choked and proper water is available at the input of the pump then the current drawn by the pump is y A and the value of y A is greater than x A. Said condition indicates normal functioning of the pump.
5. Check the condition of the carbon filter by monitoring the current drawn by the pump. In said case, the pump output is blocked due to carbon blockage and the load on the pump is more as compared to the previous stages of the pump. The current drawn by the pump is z A and the value of z A is higher than y A but the difference is not too high as in x A and y A. Hence, the system indicates the choking of the carbon filter and proper functioning of the RO membrane filter.
6. In case, the system depicts proper functioning of the LPS, sediment filter and the carbon filter and low flow rate of the membrane then said situation is due to improper functioning of the RO membrane filter and replacement of said filter is required.
[022] The current drawn by the pump is the most important decision making factor in the multi stage filter system of the water purification system. Measurement of the actual pump current considering all different possibilities is also challenging and important. Therefore, current sensing requires being accurate.

[023] For the purpose of decision making, all the conditional decisions are not instantaneous as such situation may occur due to any other faulty situation. Hence, the decision is made by capturing enough data points to take a call. Said data points may be monitored for about 1 hour (data capture frequency could be 1 min, 2min etc.) and if all the captured data points are falling within the conditional limits then only any decision is taken. The data point interval varies depending upon the limitation of each system. Once a decision is made, said decision displays on the condition unless the condition is recovered.
[024] As decision is being made using the data points, system recovery also happen with the data points. After RO membrane filter change, new data points are captured during the purification process and if all the data points are measured to be above the limit then the system comes out of RO membrane filter change state.
[025] According to a preferred embodiment of the present invention, the status of the sediment filter and the carbon filter is measured by pump current. The pump draws different amount of current depending on the load on said pump and the load is the water flowing through the pump. The pump is in dry run state when said pump is running without water and in a no load condition. The pump is in normal working condition or wet run state when the output water flow is same as the input water flow. The pump is in blockage state when the output flow of the water is blocked and the current drawn by the pump is more than the dry run state and the wet run state. For instance, the current drawn by the pump at Dry Run, Wet Run and Blockage state is x, y and z Ampere (A) respectively, the proportion of said pump currents would be x < y < z. Said pump current is measured by employing a unique electronic circuit design that is a part of the product electronic unit. The parameter values for x, y and z varies for different products depending on pump specifications.
[026] The status of the working of said filters are detected by the following steps:

1. Availability of water supply at the input of the RO water purifier indicates that there is no LPS fault and the purification process would run smoothly.
2. During purification process, the current drawn by pump is measured to be x A, as mapped in the range of dry run state of the pump, indicates that the pump is not receiving the water and is running in Dry Run state. The above stated possibility only occurs when the sediment filter is not able to provide the water output that is connected with the pump through a solenoid valve, considering that solenoid valve is working as per requirement. Hence, the pump runs under the Dry Run state in case of sediment filter choking.
3. During the purification process, the current drawn by pump is measured to be z A, as mapped in the range of blocking is the result of building of pressure on the pump at the output side. As the placement of the carbon filter is immediately after the pump depicts a direct connection and indicates that the carbon filter is chocked and the pump is running under Blockage state.
4. During the purification process, the current drawn by the pump is measured to be y A, as mapped into the range of wet run indicates the smooth running of the sediment and carbon filters without any chocking at that particular time.
[027] During the process of detection of sediment and carbon chocking, said system is making decisions based on actual data points captured during purification. Said indication is completely different from normal filter change indications. Hence, there is no option of manual reset and system automatically recovers based on the new data points.
BRIEF DESCRIPTION OF THE DRAWINGS:
[028] Figure 1 illustrates the basic structure of a purification system installed in an RO water purifier comprises of the components.
[029] Figure 2 illustrates the basic life cycle of an RO membrane.

[030] Figure 3 illustrates the overall concept of the monitoring of said filters. [031] Figure 4 illustrates the electronic circuit installed in the water purifier.

We Claim:

1.A monitoring system for ascertaining performance of sediment filter and carbon
filter in a RO water purifier, said monitoring system comprising of:
i. a Low Pressure Switch (LPS) for checking the availability of required
amount of input water pressure;
ii. a sediment filter;
iii. a solenoid valve;
iv. a pump for the purpose of drawing the current;
v. a carbon filter;
vi. an RO membrane; and
vii. a flow sensor for measuring the membrane output flow rate;
characterized in that the status of said sediment filter, carbon filter and RO membrane is measured by the current drawn by the pump wherein the basic load on said pump is water and the load varies depending on the flow of water form said pump without any blockage at the other end and an electronic circuit is designed with specific specifications for measuring the current drawn by said pump at different stages of purification of water thereby determining the performance and actual life of filters.
2. The system claimed in Claim 1, wherein the perfect working of said water purifier is determined by proper TDS reduction and proper output flow.
3. The system as claimed in Claim 1, wherein the working of sediment filter and carbon filter is determined by the following steps:
i. confirming the availability of water supply at the input of the RO water
purifier; ii. reviewing the current drawn by the pump;

iii. comparing the current drawn by the pump to the range of dry run state, wet run state or blockage state of the water purifier.
4. The system as claimed in Claims 1 and 3, wherein the said system indicates dry run state of said water purifier in case of sediment filter choking depending on the current drawn from the pump.
5. The system as claimed in Claims 1 and 3, wherein the said system indicates blockage state of said water purifier in case of carbon filter choking depending on the current drawn from the pump.
6. The system as claimed in Claim 1, wherein the flow rate of said RO membrane is determined by the following steps:
i. confirming the availability of water supply to the RO water purifier as
indicated by no LPS state error; ii. checking the condition of the sediment filter by monitoring the current
drawn by the pump and an indication is displayed; iii. a different indication is provided for sediment chocking and the
requirement for replacing the sediment filter; iv. checking the condition of the carbon filter by monitoring the current drawn
by the pump.
7. The system as claimed in Claim 1, wherein the said system determines the life of a filter based on multiple actual data points captured by the electronic circuit during the process of water purification.
8. The system as claimed in Claim 1, wherein the electric circuit displays different indications for indicating the state of said water purifier depending on the current drawn by the pump.

9. The system as claimed in Claimed 1, wherein said system follows the process of self-learning or machine learning for recovery of the change of state of said water purifier automatically.