Guangzhou Dow Environmental Protection Technology Co., Ltd. Product Technology

Single-stage reverse osmosis process
Raw water → original water tank → original water pump → multi-media filter (quartz sand filter) → activated carbon filter → soft water processor (adding scale inhibitor device) → precision filter → high pressure pump → first-stage reverse osmosis ( RO ) device → UV disinfection device (ozone sterilization device) → water point
Process Description
1 , the original water tank
1 ) Role: Overcoming the instability of the water supply of the pipe network, ensuring the stable and continuous water supply of the whole system; at the same time, it also provides a guarantee for the long-term performance of each equipment.
2 ) Selection: PE material or stainless steel water tank.
3 ) Control: The water tank is equipped with a high water level float valve and a low water level liquid level switch. It has the advantages of high reliability , low price , simple structure and convenient installation. When the water level is high, the float valve closes and stops entering the water. When the water level is at a low water level, the high water level float valve opens and begins to fill the water tank. At the same time, the low water level switch is turned off and the booster pump stops working.
2 , the original water pump
1 ) Role: Provide the necessary working pressure for pre-processing each equipment.
2 ) Selection: According to the pre-treatment equipment design pressure drop (the maximum pressure drop of each filter equipment is 0.05Mpa ), and the pressure before the high pressure pump can not be less than 0.5Kg/cm2 , determine the working pressure of the booster pump.
3 ) Control: Adjust the pressure and water intake with a regulating valve after the pump.
3 , mechanical filter (quartz sand filter)
1 ) Function: The raw water is first passed through a mechanical filter, and 12-24 mesh of exquisite quartz sand is placed in the filter , so that suspended impurities such as flocs and rust in the raw water are trapped in the process. Since the mechanical filter traps a large amount of suspended impurities during operation, in order to ensure the normal operation of the filter, the filter must be periodically rinsed and backwashed.
2 ) Selection: FRP material (glass fiber reinforced plastic) container is selected .
3 ) Control: The backwashing operation of the mechanical filter adopts a manual controller, and the filter should be cleaned once a day for 10-20 minutes.
4 , activated carbon filter
1 ) Action: This process uses an activated carbon filter as a pretreatment for the reverse osmosis unit, which is very important. The reverse osmosis system requires an influent index of SDI ≤ 5 and a residual chlorine of <0.1 mg/L . In order to meet the water inflow requirements, the raw water needs to be further purified to achieve the infiltration index of reverse osmosis. The carbon filter is placed in front of the reverse osmosis unit and has two main functions:
A , adsorption of some organic matter in water, the adsorption rate is about 60%
B. Adsorb the residual chlorine in the water. Adsorption of inorganic colloids, organic colloids, and soluble organic polymer impurities having a particle size of about 10-20 angstroms and residual chlorine which is difficult to remove in a sand filter. The reason why activated carbon can be used to adsorb active materials with a particle size of several tens of angstroms is due to the existence of a large number of micropores and grain gaps with an average pore diameter of 20-50 angstroms. This structural feature of activated carbon makes its surface adsorbed. The area can reach 500-2000 m2/g . Since the molecular diameter of the general organic matter is slightly less than 20-50 angstroms, the activated carbon has a strong adsorption effect on organic substances. In addition, activated carbon has a strong dechlorination ability. Since residual chlorine has strong oxidizing property, residual chlorine reacts with carbon to form carbon dioxide and chloride ions, so only a small amount of carbon is lost, so dechlorination of activated carbon can be used fairly. Long time. Activated carbon not only has the above functions, but also removes odors and pigments in water and improves the clarity of water. After using activated carbon for a period of time, its adsorption capacity decreases and needs to be regenerated or replaced. Therefore, after the raw water passes through the carbon filter, the water quality can be greatly improved, and the pollution to the reverse osmosis membrane can be reduced. The treated water quality can reach the influent water quality requirement of the reverse osmosis unit (residual chlorine <0.1 mg/L ).
2 ) Selection: The glass fiber reinforced plastic container is used, and the expansion ratio is 40% .
3 ) Control: The control of the activated carbon filter adopts the manual controller. Since the activated carbon filter absorbs a large amount of suspended impurities in the work, in order to ensure the normal operation of the system, the flushing and backwashing must be performed every day. The washing process is performed by the cleaning time. 15-30 minutes.
5 , automatic water softener or dosing device
1 ) Action: The process of removing water hardness ( Ca2+ , Mg2+ ) is called softening. The device is filled with 001 × 7 strong acid type Na ion exchange resin, and the calcium and magnesium ions in the raw water are replaced by sodium ions, so that the residual hardness in the raw water is less than 0.03 mmol/L . The purpose of softening is to prevent fouling on the surface of the reverse osmosis membrane to prolong the service life and treatment efficiency of the reverse osmosis membrane.
2 ) Selection: Water softener is FRP container
3 ) Control: The control system adopts the American automatic control valve type. According to the set time / flow control valve head may be automatically recycled resin, complete absorption of salt \ backwashing, are red \ filling process. The water softener is equipped with a regeneration tank. The salt and water volume of the salt tank should be checked daily and the salt should be replenished in time (Iodized salt and other additives are prohibited).
6 , precision filter
1 ) Role: Precision filtration is also known as security filter. It is a treatment process before raw water enters the reverse osmosis membrane unit. PP filter core has the characteristics of large filtration flow, large amount of dirt and small pressure loss, which can block impurity particles of different particle sizes and integrate surface filtration and deep filtration. The precision filter is also blocked after a certain period of use. Therefore, after a certain period of time, the PP melt-blown filter element must be replaced. Replacement basis: The pressure difference before and after precision filtration is changed at 0.05-0.1Mpa .
2 ) Selection: use stainless steel container .
7 , high pressure pump
1 ) Role: The high pressure pump is the working pressure supplied to the reverse osmosis system for the required water flow and water quality. After the filtered water passes through the pump body, the pressure of about 10 kg is reached to meet the water inlet pressure of the membrane body, and the water output of the pure water is ensured.
2 ) Selection: According to the working pressure required for the reverse osmosis membrane, the Grundfos vertical multi-stage high pressure pump is used.
3 ) Control: When the raw water pressure gauge pointer reaches 2KG , press the water production switch, the high pressure pump starts, and the water production starts. A pressure protection switch is arranged in front of the high pressure pump. When the inlet water pressure is lower than 1KG , the pressure protection switch is closed and the high pressure pump stops working.
8 , reverse osmosis device (pure water device)
1 ) Role: The reverse osmosis unit is the main part of the purified water production line. This device uses an energy-saving composite membrane ESPA type reverse osmosis membrane element produced by Nitto Energy Co., Ltd. of Japan . The ESPA series is a brackish water desalination membrane with high salt rejection. High water flux can be obtained at lower operating pressures with an average salt rejection of 99.5% . Since the ESPA film has the above advantages, it provides a wider space for the selection of pumps, pressure vessels, pipes, valves and the like. And the use of a smaller power motor can meet the needs of the work. At the same time, the high water flux and high desalination rate of the ESPA membrane greatly reduce the equipment manufacturing cost and system equipment investment cost, and can save a lot of energy, reduce the operating cost of the system and improve the water quality.
2 ) Selection: American Hyde Energy ESPAI-4040/8040 . The reverse osmosis unit is designed to produce a water temperature of 25 ° C and a water utilization rate of 70% .
9 , water tank (original water tank)
Role: Reserve reverse osmosis product water and provide a stable water supply for the next level of system work. Control: There are high and low level switches in the water tank to control the high pressure pump and booster pump. When the balance tank is at a low water level, the booster pump automatically starts and begins to produce water. When the water tank is at a high water level, the high pressure pump stops working.
10 , booster pump
1 ) Role: Provide the necessary working pressure to the mixed bed in the latter stage.
2 ) Control: Adjust the pressure and water intake (manual operation) with the regulating valve after the pump.
11 , purified water tank (product water tank)
1 ) Action: Mix the bed water, enter the purification water tank, and then send it to each water point through the purified water tank.
2 ) Control: The high- and low-level switch is installed in the purified water tank to control the feed pump of the mixed bed. When the purified water tank is at a low water level, the mixed bed feed pump starts to work, and the purified water tank is filled with water; when the water level is high, the mixed bed feed pump stops working.
12 , fine filter processor
1 ) Role: The use of 1 μ m polypropylene material filter element can effectively trap the tiny particles in the pipeline and the dead bacteria. Its long life, large flow and high filtration precision ensure the sterile water supply of the production line. After the fine filter processor has been used for a certain period of time, the filter element must be replaced due to the drop of the fouling water production. The replacement basis is: the pressure difference before and after the filtration is changed at 0.05-0.1Mpa .
13 , testing instrumentation
1 ) The reverse osmosis main unit is provided with a membrane front pressure gauge and a membrane post pressure gauge to detect the working pressure of the membrane, and is provided with a system path operation display, and the fresh water flow meter and the concentrated water flow meter detect the concentrated and fresh water flow.
2 ) The reverse osmosis host also has a conductivity meter and a resistivity meter. Online detection of fresh water quality is both intuitive and convenient, and the water quality changes of the product water can be observed at any time.
3 ) The pretreatment is equipped with a pressure gauge to observe the operation status of the equipment at any time, and to analyze the operation status of the equipment.
Application range
1. Preparation of pure water and ultrapure water in industries such as electronics, industry, medicine, food, etc.;
2. Purification and preparation water for process water / chemical circulating water and chemical product manufacturing in light textile and chemical industry ;
3. Water for purification and preparation of water for food and beverage industry, drinking pure water, beverages, beer, liquor, health care products, etc.;
4. In the industrial production, the useful substance and concentration and recovery of the aqueous solution;
5. Pre-desalting treatment of high-pressure boiler feed water in boilers such as boiler feed water, thermal power boilers, mines and low-pressure boiler power systems in power industry;
6. Desalination of brackish water and seawater;
7. The pure water device is used as a first-grade desalination equipment for high-purity water production.
8. Communities, real estate properties, schools, factories, hospitals, tea houses, hotels, beauty salons, canteens, etc.
9. It can be used for the preparation of bottled water, mineral water and other filling water.
10. Water for electronic industry Washing water for electronic components such as integrated circuits, silicon wafers, display tubes, etc.
11. Water for the pharmaceutical industry, large infusions, injections, tablets, biochemical products, equipment cleaning, etc .;
12. Seawater, brackish water desalination Island, ship, offshore drilling platform, brackish water area
13. Other process water Ultra-pure water for automobile, home appliance coating, coated glass, cosmetics, fine chemicals, etc.
14. Water for electroplating industry --- cleaning workpiece water , tank water