Water purifying system and backwash module control method thereof

Patent metadata

Field	Value
Publication number	US-10967309-B2
Application number	US-201916406221-A
Country	US
Kind code	B2
Filing date	May 8, 2019
Priority date	Oct 21, 2015
Publication date	Apr 6, 2021
Grant date	Apr 6, 2021

Abstract

Disclosed herein is a water purifying system, including: a raw water tank configured to store raw water; a filter unit configured to include a plurality of filtration modules for purifying the raw water and a plurality of valves for feeding or cutting off the raw water; a raw water pump configured to feed the raw water from the raw water tank to the filter unit; and a backwash module configured to feed backwash water to the filter unit, in which some of permeate water permeated by the filter unit is fed to the backwash module to be used as the backwash water and a feed pressure of the backwash water is fed by the raw water pump.

First claim

What is claimed is:

1. A method of controlling a backwash module configured to perform a backwash by feeding backwash water to a raw water filter, the backwash module including a first inlet configured to receive raw water from a tank storing the raw water, a second inlet configured to receive a portion of permeate water permeated by the raw water filter, a first outlet through which the received raw water is discharged, and a second outlet through which the backwash water is discharged, the method comprising:
using the received raw water to apply pressure to the portion of permeate water such that the backwash module feeds the portion of permeate water to the raw water filter as the backwash water, and
using the received portion of the permeate water to apply pressure to the received raw water such that the backwash module feeds the raw water back to the tank.

2. The method of claim 1 , further comprising:
opening second and fourth valves ( 530 , 570 ) respectively connected to the first outlet and the second inlet in order to feed the portion of the permeate water to the backwash module; and
opening first and third valves ( 510 , 550 ) respectively connected to the first inlet and the second outlet in order to perform the backwash.

3. The method of claim 2 ,
wherein the first and third valves ( 510 , 550 ) are closed when feeding the portion of the permeate water to the backwash module, and
wherein the second and fourth valves ( 530 , 570 ) are closed when performing the backwash.

4. The method of claim 1 , further comprising:
detecting a flux of the raw water received from the tank; and
controlling the flux of the raw water at the first inlet depending on the detecting.

5. The method of claim 4 , wherein the flux of the raw water is controlled based on a preset backwash flux.

6. The method of claim 1 , further comprising stopping an operation of the raw water filter when the backwash is performed by stopping a flow of the raw water to the raw water filter during the backwash.

7. The method of claim 1 , further comprising controlling the pressure applied to the portion of permeate water by pumping the raw water received from the tank to the backwash module.

8. The method of claim 7 , further comprising:
directly applying the permeate water from the raw water filter to a reverse osmosis system such that water fed to the reverse osmosis system is reduced by as much as an amount of the backwash water used for the backwash; and
compensating for the reduction in flux of the feed water to the reverse osmosis system by increasing a flux of the raw water pumped to the backwash module.

9. The method of claim 1 , further comprising:
discharging the backwash water to a dirty water tank after the backwash of the raw water filter such that water fed to the backwash module is reduced by as much as an amount of the backwash water discharged to the dirty water tank.

10. The method of claim 1 , further comprising:
compensating for the reduction in flux of the feed water to the backwash module by increasing an amount of permeate water supplied to the backwash module as a required amount of the backwash water increases.

11. A backwash module configured to perform a backwash by feeding backwash water to a raw water filter, the backwash module comprising:
a first inlet configured to receive raw water from a tank storing the raw water;
a second inlet configured to receive a portion of permeate water permeated by the raw water filter;
a first outlet in fluid communication with the raw water tank and through which the received raw water is discharged to the raw water tank; and
a second outlet through which the backwash water is discharged,
wherein the backwash module includes a pressurized volume formed as one of a pressure vessel and a pressure tank, and
wherein the pressurized volume is compartmentalized by first and second porous plates to include:
a first compartment communicating with the first inlet and the first outlet;
a second compartment communicating with the second inlet and the second outlet; and
a common compartment configured to receive the raw water through the first porous plate and to receive the backwash water through the second porous plate.

12. The backwash module of claim 11 , further comprising:
a first valve ( 510 ) to control the raw water received at the first inlet;
a second valve ( 530 ) to control the raw water discharged at the first outlet;
a third valve ( 550 ) to control the backwash water discharged at the second outlet; and
a fourth valve ( 570 ) to control the permeate water fed to the second inlet.

13. The backwash module of claim 11 , wherein the pressurized volume consists of a plurality of pressurized volumes arranged according to one of a vertical pattern and a horizontal pattern, each of the plurality of pressurized volumes including a movable member configured to move lengthwise within the pressurized volume in correspondence with a cycle of a preset backwash time.

14. The backwash module of claim 11 , further comprising:
a movable member configured to move between the first and second porous plates,
wherein the movable member travels toward the first porous plate when the portion of permeate water is received at the second inlet, and travels toward the second porous plate when the raw water is received at the first inlet.

15. The backwash module of claim 14 , further comprising:
the movable member configured to move between the first and second porous plates,
wherein the movable member travels toward the first porous plate when the raw water is discharged from the first outlet, and travels toward the second porous plate when the backwash water is discharged from the second outlet.

16. The backwash module of claim 15 , wherein the movable member is one of a piston and a diaphragm.

17. A backwash module configured to perform a backwash by feeding backwash water to a raw water filter, the backwash module comprising:
a first inlet configured to receive raw water from a tank storing the raw water;
a second inlet configured to receive a portion of permeate water permeated by the raw water filter;
a first outlet through which the received raw water is discharged;
a second outlet through which the backwash water is discharged; and
first and second porous plates configured to compartmentalize a pressurized volume in the backwash module, the pressurized volume including a first compartment communicating with the first inlet and the first outlet, a second compartment communicating with the second inlet and the second outlet, and a common compartment configured to receive the raw water through the first porous plate and to receive the backwash water through the second porous plate,
wherein the first outlet is in fluid communication with the raw water tank and the raw water from the first compartment is fed back to the raw water tank via the first outlet.

18. The backwash module of claim 17 , further comprising:
a second valve to control the raw water discharged at the first outlet; and
a fourth valve to control the permeate water fed to the second inlet,
wherein the second and fourth valves ( 530 , 570 ) are opened in order to feed the portion of the permeate water to the backwash module and are closed when performing the backwash.

19. The backwash module of claim 17 , further comprising:
a first valve to control the raw water received at the first inlet; and
a third valve to control the backwash water discharged at the second outlet; and
wherein the first a

Assignees

• Doosan Heavy Ind & Construction Co Ltd
• Doosan Heavy Ind Constr Co Ltd

Inventors

• Lee Woo Nyoung
• Park Sung Won

Classifications

• B01D61/22 Primary

  Controlling or regulating · CPC title

• B01D2313/50

  Specific extra tanks · CPC title

• B01D2311/2649

  Filtration · CPC title

• B01D61/025

  Reverse osmosis; Hyperfiltration · CPC title

• B01D29/663 Primary

  by using membranes · CPC title