1. Raw water tank
The device prevents the water directly pumped by the booster pump from the pipe network from damaging the booster pump or affecting the normal operation of the system due to insufficient flow and unstable pressure. Large equipment must be equipped with water inlet electric butterfly valve.
- The function of the floating ball valve is to control the amount of raw water inflow, and to replenish water in time when the system is running.
- The liquid level sensor has a medium water level and a low water level, and its function is to control the start and stop of the booster pump; when the water level of the water tank is above the medium water level, the booster pump can automatically start; when the water level of the water tank is lower than the low water level, the booster pump The pump stops automatically.
2. Add coagulant device
Commonly used dosing pumps are: American Milton Rowe and American Pasifida.
Coagulation—-Using coagulants such as iron salts, aluminum salts, and polymers to form large-particle precipitates with impurities in the water through flocculation and bridging, which are then removed by other equipment, such as clarification and filtration.
Add an appropriate amount of coagulant to effectively coagulate the colloids and organic impurities in the water, so that the above substances can form large particle precipitates or flocs through flocculation and bridging, and then go through pretreatment filtration to improve the filtration effect of pretreatment. SDI (Pollution Index) ≤5. If the SDI value of the influent water is too large, a coagulant aid needs to be added.
Commonly used coagulants are: aluminum sulfate, polyaluminum chloride, ferrous sulfate, ferric chloride, etc.
Commonly used coagulants are: calcium oxide, calcium hydroxide, polyacrylic acid amine, sodium carbonate, etc.
Control: start synchronously with the original water pump.
3. Preprocessing (aka Preprocessing)
At present, there are three kinds of pretreatment filters that we often pass through: stainless steel filter, glass fiber reinforced plastic filter and carbon steel lined rubber filter. The pretreatment filtration is divided into three parts: multi-media filtration, iron and manganese removal device, activated carbon filtration and softening filtration; American Atuzu multi-way valve can be used to automatically control the filter material in the filter tank according to the set time. Backwash and forward wash; or choose manual operation control.
Before the water is purified, the preliminary treatment is carried out in advance, so as to obtain good results and improve the water quality in the purification of water. Since there are a lot of impurities in natural water, such as sediment, clay, organic matter, microorganisms, mechanical impurities, etc., the existence of these impurities seriously affects the quality and treatment effect of purified water, so it is necessary to reduce or reduce some impurities before polishing. removed, which requires preprocessing.
4. Scale inhibitor device
1. Surround colloidal particles with anionic or non-ionic polymers to stabilize them in a dispersed state. Such agents are called dispersants. e.g. Phosphate
2. Turn metal ions into a chelated ion or complex ion, which inhibits them from combining with anions to produce precipitates. Such agents are called chelating agents and complexing agents. Such as: EDTA
3. Using the coagulation and bridging effect of the polymer coagulant, the colloidal particles are formed into alum flowers and suspended in water. e.g. Polyacrylamide
The main function of this device is to prevent the reverse osmosis membrane from fouling. The American metering pump is used to add the chemicals, and the dosage is accurate and the stability of the equipment is good.
Commonly used dosing pumps are: American Milton Rowe and American Pasifida.
Commonly used scale inhibitors are: sodium hexametaphosphate, organic phosphate, polyacrylate.
Control: High-pressure pumps of the same stage start synchronously.
5. Fine filter (also known as security filter)
The device is mainly used for fine filtration of the influent water of the reverse osmosis system, the purpose is to reduce or eliminate the filter material particles leaked from the pretreatment equipment and play a final protective role to ensure that the final water entering the reverse osmosis system meets the requirements.
Filtration precision: generally 10um, 5um, 1um
There are two kinds of fine filter (blue filter) ABS material and stainless steel material; blue filter has 10 inch and 20 inch, stainless steel filter has 10 inch, 20 inch, 30 inch and 40 inch 5 core, 7 core, 10 core, 20 cores with a total of 16 specifications.
6. Voltage Controlled Switch
Control the start and stop of the high-pressure pump to prevent the high-pressure pump from running under the condition of water shortage and insufficient water supply, and guide the damage of the high-pressure pump.
Generally, the high-pressure pump can start automatically when the inlet water pressure is greater than 1kg, and automatically stop when it is less than 0.5kg.
7. High-pressure pump
Apply a constant osmotic pressure to the reverse osmosis system.
Control: The automatic start and stop are controlled by the water level of the original water tank, the pressure switch, the regeneration micro switch, and the water level of the pure water tank.
8. Inlet solenoid valve
The main function of the device is: when the pure water tank is full or the automatic machine head is backwashed and regenerated, the system automatically controls the electromagnetic shutdown to automatically stop the operation of the system.
9. Reverse osmosis unit (RO membrane technology)
1) Working principle:
Osmosis – When two solutions of different concentrations are separated by a semi-permeable membrane, the solvent in the dilute solution will pass through the semi-permeable membrane into the concentrated solution. Reverse osmosis is a scientific method to reverse its natural osmosis process. On the concentrated solution side, when an external pressure is greater than the osmotic pressure, the solvent will reverse its original permeation direction and enter the dilute solution from the concentrated solution side through the semi-permeable membrane. in solution.
2) Inlet water requirements: Turbidity≤2 degrees Water temperature: 5-35℃ SDI≤5 Fe≤0.1mg/L
PH: 4-11 Residual chlorine ≤ 0.1mg/L
3) The system can use the world’s most advanced Dow membrane elements, American Hyde energy membrane elements, Japan Toray membrane elements, and Shihan membrane elements as the main elements. 97-99%, and can effectively remove impurities such as suspended solids, organic colloids, organic matter, bacteria, viruses, and pyrogens in the water. In order to ensure the stable performance and long-term operation of the RO device, a regular automatic flushing device is set up.
4) The working pressures of RO used in my country are: ultra-low pressure membrane —- 7-10kg, low pressure membrane —- 15kg, high pressure membrane —- 55kg.
5) Membrane material: The commonly used membrane is a fully aromatic polyamide composite membrane with high cross-linking degree (abbreviation: polyamide composite membrane)
The less commonly used membranes are cellulose acetate membranes.
10. Primary pure water intermediate tank (also known as intermediate water tank)
The function of the intermediate water tank is to control the operation and stop of the booster pump, the primary high-pressure pump and the secondary high-pressure pump, ensure the water supply to the secondary high-pressure pump, prevent the secondary high-pressure pump from running under water shortage conditions, and guide the operation of the secondary high-pressure pump. damage.
The middle water tank has three water levels: high, medium and low. When the water level of the water tank is low, the secondary high-pressure pump will automatically stop running until the water in the water tank reaches the medium water level or higher. When the water level is high, the booster pump and the first-stage high-pressure pump automatically stop running.
11. Secondary alkali adding device
For example, if the device is set to add an appropriate amount of NaOH (sodium hydroxide), the carbon dioxide and the monomolecules passing through the RO membrane will be chemically reacted to form molecular clusters, which will better remove secondary ions, thereby improving the effect of secondary water production. Generally, the conductance of secondary product water can be less than 2us/cm², and it can also be less than 1us/cm² when adjusted properly.
Control: start synchronously with the secondary high pressure pump.
Xi’an CHIWATEC Water Treatment Technology is a high-tech enterprise specialized in various water processing devices. Aside from these individual products, which cover a number of types and series, we can also help with related comprehensive engineering projects. Thanks to our hard work and dedication upon our founding, we are now one of the fastest-developing water treatment equipment manufacturers in Western China.