Patent Publication Number: US-2023150847-A1

Title: Pressure balancing system for two sides of an edr film stack

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a pressure balancing system of filtration films of a water purifier, especially to a pressure balancing system for two sides of an electrodialysis reversal (EDR) film stack. 
     2. Description of the Prior Art(s) 
     With improvement of people&#39;s quality of life, many families have water purifiers installed in their houses, so as to ensure the safety of drinking water. However, after the water purifier has been used for a long time, a film stack in the water purifier is easily damaged due to difference in pressure on two sides of the film stack, thereby affecting service life of the film stack. Consequently, the film stack has to be replaced frequently, which leads to a decrease in water purification efficiency of the water purifier. 
     There is no good solution to the aforementioned problem in conventional water purifiers. 
     To overcome the shortcomings, the present invention provides a pressure balancing system for two sides of an electrodialysis reversal (EDR) film stack to mitigate or obviate the aforementioned problems. 
     SUMMARY OF THE INVENTION 
     The main objective of the present invention is to provide a pressure balancing system for two sides of an electrodialysis reversal (EDR) film stack. The pressure balancing system includes a first source water inlet, a second source water inlet, an EDR film stack, a first pressure sensor, a second pressure sensor, a third pressure sensor, a fourth pressure sensor, a variable speed pump, a one-way valve, a clean water outlet, a waste water outlet, and a control system module. The EDR film stack has a first inlet port, a second inlet port, a first outlet port, and a second outlet port. The first source water inlet, the first pressure sensor, and the first inlet port of the EDR film stack are connected in sequence. The second source water inlet, the one-way valve, the third pressure sensor, and the second inlet port of the EDR film stack are connected in sequence. The first outlet port of the EDR film stack, the second pressure sensor, and the clean water outlet are connected in sequence. The second outlet port of the EDR film stack, the fourth pressure sensor, and the waste water outlet are connected in sequence. The variable speed pump has two ends connected to the one-way valve and the waste water outlet respectively. The control system module is electrically connected with the first pressure sensor, the second pressure sensor, the third pressure sensor, the fourth pressure sensor, and the variable speed pump. 
     The four pressure sensors are set to detect pressures of the water flowing through the two inlet ports and the two outlet ports of the EDR film stack. When the clean water outlet is opened to discharge clean water, pressure of the clean water that is to be discharged drops. Accordingly, the second pressure sensor sends a signal to the control system module to allow the control system module to adjust a rotational speed of the variable speed pump (to increase the rotational speed). Moreover, the control system module also opens the rinsing solenoid valve to adjust the pressure of the waste water that is to be discharged (to reduce the pressure). As a result, the pressure of the clean water that is to be discharged and the pressure of the waste water that is to be discharged can be substantially equal. 
     Thus, with pressure balancing system for the two sides of the EDR film stack, the pressures on the two sides of the EDR film stack can be balanced, and service life of the EDR film stack and water purification efficiency of the EDR film stack can be improved. 
     Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic diagram of a pressure balancing system for two sides of an electrodialysis reversal (EDR) film stack in accordance with the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to  FIG.  1   , a pressure balancing system for two sides of an electrodialysis reversal (EDR) film stack in accordance with the present invention includes a first source water inlet  1 , a second source water inlet  6 , an EDR film stack  3 , a first pressure sensor  2 , a second pressure sensor  4 , a third pressure sensor  8 , a fourth pressure sensor  10 , a variable speed pump  9 , a one-way valve  7 , a clean water outlet  5 , a waste water outlet  11 , and a control system module  17 . The EDR film stack  3  has a first inlet port  13 , a second inlet port  14 , a first outlet port  15 , and a second outlet port  16 . The first source water inlet  1 , the first pressure sensor  2 , and the first inlet port  13  of the EDR film stack  3  are connected in sequence. The second source water inlet  6 , the one-way valve  7 , the third pressure sensor  8 , and the second inlet port  14  of the EDR film stack  3  are connected in sequence. The first outlet port  15  of the EDR film stack  3 , the second pressure sensor  4 , and the clean water outlet  5  are connected in sequence. The second outlet port  16  of the EDR film stack  3 , the fourth pressure sensor  10 , and the waste water outlet  11  are connected in sequence. The variable speed pump  9  is a water pump with adjustable pump rotational speed and has two ends connected to the one-way valve  7  and the waste water outlet  11  respectively. The control system module  17  is electrically connected with the first pressure sensor  2 , the second pressure sensor  4 , the third pressure sensor  8 , the fourth pressure sensor  10 , and the variable speed pump  9 . 
     The pressure balancing system may further include a rinsing solenoid valve  12 . The rinsing solenoid valve  12  has two ends connected with the variable speed pump  9  and the waste water outlet  11  respectively. The control system module  17  is electrically connected with the rinsing solenoid valve  12 . With the rinsing solenoid valve  12 , pressure of waste water that is to be discharged can be adjusted and pressure on the two sides of the EDR film stack can be balanced. 
     EMBODIMENT 
     As shown in  FIG.  1   , a pressure balancing system for two sides of an EDR film stack in accordance with the present invention includes a first source water inlet  1 , a second source water inlet  6 , an EDR film stack  3 , a first pressure sensor  2 , a second pressure sensor  4 , a third pressure sensor  8 , a fourth pressure sensor  10 , a variable speed pump  9 , a one-way valve  7 , a clean water outlet  5 , a waste water outlet  11 , and a rinsing solenoid valve  12 . The EDR film stack  3  has a first inlet port  13 , a second inlet port  14 , a first outlet port  15 , and a second outlet port  16 . The first source water inlet  1 , the first pressure sensor  2 , and the first inlet port  13  of the EDR film stack  3  are connected in sequence. The second source water inlet  6 , the one-way valve  7 , the third pressure sensor  8 , and the second inlet port  14  of the EDR film stack  3  are connected in sequence. The first outlet port  15  of the EDR film stack  3 , the second pressure sensor  4 , and the clean water outlet  5  are connected in sequence. The second outlet port  16  of the EDR film stack  3 , the fourth pressure sensor  10 , and the waste water outlet  11  are connected in sequence. The variable speed pump  9  is a water pump with adjustable pump rotational speed and has two ends connected to the one-way valve  7  and the waste water outlet  11  respectively. The rinsing solenoid valve  12  has two ends connected with the variable speed pump  9  and the waste water outlet  11  respectively. A control system module  17  is electrically connected with the first pressure sensor  2 , the second pressure sensor  4 , the third pressure sensor  8 , the fourth pressure sensor  10 , the variable speed pump  9 , and the rinsing solenoid valve  12 . 
     Working principle of the pressure balancing system for the two sides of the EDR film stack is described as follows. The four pressure sensors  2 ,  4 ,  8 ,  10  are set to detect pressures of the water flowing through the two inlet ports  13 ,  14  and the two outlet ports  15 ,  16  of the EDR film stack  3 . When the clean water outlet  5  is opened to discharge clean water, pressure of the clean water that is to be discharged drops. Accordingly, the second pressure sensor  4  sends a signal to the control system module  17  to allow the control system module  17  to adjust a rotational speed of the variable speed pump  9  (to increase the rotational speed). Moreover, the control system module  17  also opens the rinsing solenoid valve  12  to adjust the pressure of the waste water that is to be discharged (to reduce the pressure). As a result, the pressure of the clean water that is to be discharged and the pressure of the waste water that is to be discharged can be substantially equal. Thus, the pressures on the two sides of the EDR film stack  3  can be balanced, and service life of the EDR film stack  3  and water purification efficiency of the EDR film stack  3  can be improved. 
     Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and features of the invention, the disclosure is illustrative only. Changes may be made in the details, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.