Accurate dosing system for reverse osmosis reducing agent

Abstract

The utility model discloses a reverse osmosis reducing agent accurate dosing system which comprises a demineralized water pipeline and a dosing pipeline, and an ultrafiltration water tank, a medicine mixer, a reverse osmosis membrane group and a reverse osmosis water producing tank are sequentially arranged on the demineralized water pipeline. A dosing tank and a dosing flowmeter are sequentially arranged on a dosing pipeline which is in butt joint with the chemical mixer to bypass the demineralized water pipeline, and a water outlet flowmeter, a residual chlorine measuring device and an ORP (oxidation reduction potential) measuring device are arranged on the demineralized water pipeline. According to the water quality change of ultrafiltration effluent, full-automatic dosing regulation and control in the reverse osmosis water production process are realized, accurate dosing is realized, a reverse osmosis membrane is prevented from being polluted, blocked or oxidized, and the service life of the membrane is prolonged.

Description

Technical Field

[0001] The utility model belongs to the technical field of desalted water and drinking water production, and in particular relates to a reverse osmosis reducing agent precise dosing system. Background Art

[0002] The membrane used in the reverse osmosis device is a practical and economical commercial membrane, but its disadvantage is that it has poor resistance to microbial erosion. Long-term use will cause a large number of microorganisms to grow. When the secreted mucus adheres to the membrane surface, the pressure difference increases, and finally the channel is blocked, causing the water flux to decrease. Once the microorganisms enter the reverse osmosis system, they are very likely to breed on the membrane surface and secrete mucus to adhere to the colloidal suspended matter and inorganic scale particles in the water, forming a microbial mucous layer. Once the mucous layer is formed, it cannot be effectively removed simply by increasing the water flow rate. The pressure difference of the membrane can be temporarily restored after cleaning with alkali and formaldehyde, but after a period of water intake, the microorganisms will reproduce again and the pressure difference will rise again. Once microbial contamination occurs on the membrane surface, biological contamination can be formed in the entire reverse osmosis membrane. In order to avoid microbial contamination, chlorine dioxide is added to the raw water as a bactericide. There will be residual chlorine in the ultrafiltration water, and high residual chlorine will damage the reverse osmosis membrane. The reverse osmosis membrane is easily oxidized by oxidants and loses its desalination function. The addition of reducing agents is to eliminate oxidizing substances such as residual chlorine in the water entering the reverse osmosis membrane, so that the redox potential of the reverse osmosis water is maintained below 200mV, thereby protecting the reverse osmosis membrane from the threat and damage of the gasification agent. However, adding too much reverse osmosis reducing agent will lead to a series of problems, including indirect pollution, ORP drop, membrane damage, system blockage, water quality changes, and yellow water from the membrane; excessive use of reverse osmosis reducing agent will have many adverse effects on the reverse osmosis membrane and its system. Therefore, during use, its dosage must be strictly and accurately controlled to ensure compatibility with the membrane material to avoid fouling or oxidation of the reverse osmosis membrane. Accurate addition of reducing agents is a difficult problem in the industry, and the key to solving this problem lies in solving the problem of delayed dosing control. Summary of the invention

[0003] Purpose of the invention: In order to overcome the deficiencies in the prior art, the utility model provides a reverse osmosis reducing agent precision dosing system, which realizes fully automatic dosing control in the reverse osmosis water production process according to the changes in the ultrafiltration effluent water quality, realizes precise dosing, avoids fouling or oxidation of the reverse osmosis membrane, and prolongs the service life of the membrane.

[0004] Technical solution: To achieve the above-mentioned purpose, the utility model provides a reverse osmosis reducing agent precision dosing system, comprising a desalted water pipeline and a dosing pipeline, on which an ultrafiltration water tank, a mixer, a reverse osmosis membrane group and a reverse osmosis water production tank are sequentially arranged, and a dosing box and a dosing flowmeter are sequentially arranged on the dosing pipeline connected to the mixer and connected to the desalted water pipeline, and an outlet water flowmeter, a residual chlorine measuring device and an ORP measuring device are arranged on the desalted water pipeline.

[0005] Furthermore, the residual chlorine measuring device comprises an inlet residual chlorine measuring sensor and an outlet residual chlorine measuring sensor, wherein the inlet residual chlorine measuring sensor is located between the outlet flow meter and the mixer, and the outlet residual chlorine measuring sensor is located between the mixer and the ORP measuring device.

[0006] Furthermore, the ORP measuring device is an ORP tester.

[0007] Furthermore, it comprises a desalination variable frequency pump and a reducing agent dosing variable frequency pump; the desalination variable frequency pump is arranged between the ultrafiltration water tank and the water outlet flow meter; the reducing agent dosing variable frequency pump is arranged between the dosing tank and the dosing flow meter.

[0008] Furthermore, the desalination variable frequency pump and the reducing agent dosing variable frequency pump are both one-in-use and one-in-standby variable frequency pumps.

[0009] Furthermore, the ultrafiltration water tank is provided with a first water tank level gauge; the reverse osmosis water production tank is provided with a second water tank level gauge; and the medicine adding tank is provided with a medicine tank level gauge.

[0010] Furthermore, it includes a control system, and the dosing flow meter, water outlet flow meter, residual chlorine measuring device, ORP measuring device, desalination frequency conversion pump, reductant dosing frequency conversion pump, first water tank level gauge, second water tank level gauge and medicine tank level gauge are respectively connected to the control system through signal transmission.

[0011] Beneficial effects: The utility model realizes fully automatic dosing control in the reverse osmosis water production process according to the changes in the water quality of ultrafiltration effluent, realizes precise dosing, avoids fouling or oxidation of the reverse osmosis membrane, solves the current problem of lag in dosing control, ensures a good pressure difference between the membranes, and prolongs the service life of the membranes, and is suitable for large-scale promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Attached Figure 1 It is a schematic diagram of the overall structure of the utility model. DETAILED DESCRIPTION

[0013] The utility model is further described below in conjunction with the accompanying drawings.

[0014] As attached Figure 1As shown, a reverse osmosis reducing agent precision dosing system includes a desalted water pipeline 1 and a dosing pipeline 2, on which an ultrafiltration water tank 3, a mixer 4, a reverse osmosis membrane group 5 and a reverse osmosis water production tank 6 are sequentially arranged, and a dosing box 7 and a dosing flowmeter 8 are sequentially arranged on the dosing pipeline 2 connected to the desalted water pipeline 1 by the mixer 4, and an outlet flowmeter 9, a residual chlorine measuring device 10 and an ORP measuring device 11 are arranged on the desalted water pipeline 1. The utility model realizes fully automatic dosing control in the reverse osmosis water production process according to the change of ultrafiltration effluent water quality, realizes precise dosing, avoids fouling or oxidation of the reverse osmosis membrane, and prolongs the service life of the membrane.

[0015] More specifically, the residual chlorine measuring device 10 includes an inlet residual chlorine measuring sensor 101 and an outlet residual chlorine measuring sensor 102. The inlet residual chlorine measuring sensor 101 is located between the outlet flowmeter 9 and the mixer 4, and the outlet residual chlorine measuring sensor 102 is located between the mixer 4 and the ORP measuring device 11. The ORP measuring device 11 is an ORP tester. The utility model includes a desalination frequency conversion pump 12 and a reducing agent dosing frequency conversion pump 13; the desalination frequency conversion pump 12 is arranged between the ultrafiltration water tank 3 and the outlet flowmeter 9; the reducing agent dosing frequency conversion pump 13 is arranged between the dosing tank 7 and the dosing flowmeter 8. The desalination frequency conversion pump 12 and the reducing agent dosing frequency conversion pump 13 are both one-in-one and one-in-one frequency conversion pumps. The ultrafiltration water tank 3 is provided with a first water tank level gauge 14; the reverse osmosis water production tank 6 is provided with a second water tank level gauge 15; the dosing tank 7 is provided with a medicine tank level gauge 16. The utility model includes a control system, wherein the dosing flow meter 8, the water outlet flow meter 9, the residual chlorine measuring device 10, the ORP measuring device 11, the desalination frequency conversion pump 12, the reducing agent dosing frequency conversion pump 13, the first water tank level meter 14, the second water tank level meter 15 and the medicine tank level meter 16 are respectively connected to the control system by signal transmission. The utility model can meet the requirements of accurate dosing control of reverse osmosis reducing agent.

[0016] The general process of achieving accurate dosing of reducing agent is as follows: when the primary reverse osmosis system is in operation, after the ultrafiltration water enters the desalination pipeline 1 through the desalination frequency conversion pump 12, the residual chlorine in the ultrafiltration effluent, the effluent flow rate, the residual chlorine in the effluent after the reaction of adding the reducing agent, and the ORP, and the discharge flow rate of the reducing agent dosing frequency conversion pump 13 are monitored in real time through the control and judgment of the control system (PLC\DCS); the control system (PLC\DCS) calculates the dosing according to the monitored residual chlorine in the ultrafiltration effluent, the effluent flow rate, the residual chlorine in the effluent after the reaction of adding the reducing agent, and the ORP, and the discharge flow rate of the reducing agent dosing frequency conversion pump 13, combined with the dosing concentration of the reverse osmosis reducing agent, and the reducing agent dosing frequency conversion pump 13 performs PID calculation according to the measurement feedback of the dosing flowmeter 8, and adjusts the dosing amount in real time to ensure that the dosing concentration of the reducing agent is reliable, meet the optimal dosing mode, achieve accurate dosing, avoid fouling or oxidation of the reverse osmosis membrane, and extend the service life of the membrane.

[0017] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A reverse osmosis reducing agent precise dosing system, characterized by: The invention comprises a desalted water pipeline (1) and a dosing pipeline (2); the desalted water pipeline (1) is provided with an ultrafiltration water tank (3), a dosing device (4), a reverse osmosis membrane group (5) and a reverse osmosis water production tank (6) in sequence; the dosing pipeline (2) connected to the dosing device (4) and connected to the desalted water pipeline (1) is provided with a dosing box (7) and a dosing flowmeter (8) in sequence; the desalted water pipeline (1) is provided with a water outlet flowmeter (9), a residual chlorine measuring device (10) and an ORP measuring device (11).

2. A reverse osmosis reducing agent precise dosing system according to claim 1, characterized in that: The residual chlorine measuring device (10) comprises an inlet residual chlorine measuring sensor (101) and an outlet residual chlorine measuring sensor (102); the inlet residual chlorine measuring sensor (101) is located between the outlet flow meter (9) and the mixer (4); and the outlet residual chlorine measuring sensor (102) is located between the mixer (4) and the ORP measuring device (11).

3. A reverse osmosis reducing agent precise dosing system according to claim 1 or 2, characterized in that: The ORP measuring device (11) is an ORP tester.

4. A reverse osmosis reducing agent precise dosing system according to claim 2, characterized in that: It comprises a desalination variable frequency pump (12) and a reducing agent dosing variable frequency pump (13); the desalination variable frequency pump (12) is arranged between an ultrafiltration water tank (3) and a water outlet flow meter (9); the reducing agent dosing variable frequency pump (13) is arranged between a dosing tank (7) and a dosing flow meter (8).

5. A reverse osmosis reducing agent precise dosing system according to claim 4, characterized in that: The desalination variable frequency pump (12) and the reducing agent dosing variable frequency pump (13) are both variable frequency pumps with one in use and one in reserve.

6. A reverse osmosis reducing agent precise dosing system according to claim 4, characterized in that: The ultrafiltration water tank (3) is provided with a first water tank liquid level gauge (14); the reverse osmosis water production tank (6) is provided with a second water tank liquid level gauge (15); and the medicine adding tank (7) is provided with a medicine tank liquid level gauge (16).

7. A reverse osmosis reducing agent precise dosing system according to claim 6, characterized in that: It comprises a control system, wherein the dosing flow meter (8), the water outlet flow meter (9), the residual chlorine measuring device (10), the ORP measuring device (11), the desalination frequency conversion pump (12), the reducing agent dosing frequency conversion pump (13), the first water tank liquid level meter (14), the second water tank liquid level meter (15) and the medicine tank liquid level meter (16) are respectively connected to the control system through signal transmission.

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