High-Purity Water Treatment Systems | For Electroplating, Glass Coating & Cleaning

Ⅰ. Ultra-Pure Water Systems for Electroplating &Glass Coating Overall Process Overview

 Qingqing Spring Water Treatment Company based on the quality of raw water and the actual needs of users, recommended the use of single-stage reverse osmosis + mixed bed water treatment system. The system process is mature, easy to operate and low operating costs, high purity water quality up to 18 megohm. Processing flow: raw water through the pretreatment system to meet the requirements of reverse osmosis water, and then by reverse osmosis to remove most of the salts, and finally through the mixed bed of deep desalination, so that the quality of water in line with the industrial ultrapure water standards.

Ⅱ. Ultra-Pure Water Systems for Electroplating &Glass Coating Pretreatment System

1. The importance and purpose of pretreatment

 • pretreatment of reverse osmosis device for safe and reliable operation and economy is crucial, aimed at solving the membrane surface scaling, colloid and suspended solids fouling blockage, organic fouling blockage, microbial fouling blockage, oxidizing substances damage to the membrane as well as to ensure that the water production is stable, to ensure stable operation and prolong the service life of the reverse osmosis system.

2. Pretreatment water design parameters

 • Capacity 10m³/h; pollution index SDI ≤ 4; residual chlorine ≤ 0.1ppm; turbidity <1NTU; concentrated water Langelier index LSI <2.

3. Pretreatment part of the main equipment role

 • Raw water tank: storage of external water network into the system of raw water, such as municipal water, groundwater, river water, lake water, etc., to regulate the flow of incoming water and pressure changes, to prevent fluctuations affecting the operation of the system, to ensure that the amount of incoming water is stable. Setting liquid level switch, low liquid level automatically stops the raw water booster pump, and the middle liquid level automatically starts.

 • Raw water booster pump: to provide normal operation of the subsequent equipment required for the water supply pressure and flow.

 • Roots fan: to meet the multi-media filter gas and water backwash gas demand, and at the same time in the mixed-bed regeneration process for resin mixing.

4. Multi-media filter:

 Using different specifications of anthracite and quartz sand, with a running speed of 10 - 15m / h to remove sediment, suspended solids, colloids and other impurities in the raw water, reduce the SDI value, preliminary purification of raw water, reduce turbidity, to ensure that the filtration of water contamination index SDI15 ≤ 4. Work for a period of time need to be backwashed to restore the filter effect of the filter media, the backwash using a gas-water mixing method, carried out in six steps, backwashing water from the backwash water pump (no backwash). The backwash water is supplied by the backwash pump (without backwash pump, use raw water booster pump) and the flow rate is adjusted, and the intensity makes the filter layer expand by 15-25%, and the Roots fan sends air into the air when the air-water backwash is carried out, with the intensity of 18-25 liters/s-m², and the raw water is used for the backwash water.

5. Scale inhibitor dosing device:

 Add scale inhibitor to prevent the RO membrane element concentrated water side of the dissolved solids scaling affect membrane performance. Composed of SEKO metering pump and dosing tank, metering pump running smoothly and accurately measured, dosing volume and liquid configuration to be manually operated.

6. Security filter:

 Polypropylene filter element, filtration accuracy of 5.0μm, stainless steel shell structure, to prevent fine particles of impurities harm reverse osmosis membrane elements and affect the amount of water. When the pressure difference between the inlet and outlet of the filter reaches 0.8kg/cm², it is necessary to replace the filter element, and the structure meets the requirement of rapid replacement.

Ⅲ. Reverse osmosis host part

1. The importance of reverse osmosis device

 • Reverse osmosis device is the core part of the system pre-desalination, removes most of the inorganic salts and almost all of the organic matter, microorganisms and colloids, and its desalination rate directly affects the mixed bed regeneration cycle.

2. Reverse osmosis desalination part of the composition of

 • By the high-pressure pump, reverse osmosis membrane, membrane pressure vessel, instrumentation, reverse osmosis cleaning device and other components. Membrane pressure vessel selects domestic equipment, high-pressure pump, reverse osmosis membrane elements, pressure protection switch, conductivity meter, flow meter and other imported products. Designed as a set of 5m³/h reverse osmosis device, the high-pressure pump selects Grundfos products, and the overflow parts are SUS304 stainless steel structure, with small volume, high efficiency and low noise. The membrane element is made of polyamide composite membrane from Dow Chemical Company of the U.S.A. The membrane pressure vessel is made of glass fiber reinforced plastic (FRP) pressure membrane tube specially designed for rolled RO components, which can be equipped with 5 membrane elements, withstanding pressure of 300psi and length of about 2.3 meters, with smooth inner wall, easy loading and unloading, not easy to breed bacteria and anticorrosion.

3. Reverse osmosis pre-desalination part of the water production design parameters

 • Treatment capacity ≥ 5m³/h; recovery rate ≥ 60%; initial desalination rate ≥ 97%.

Ⅳ. Degassing tower, intermediate water tank part

1. Degassing tower set the reason

 Reverse osmosis membrane on the gas without removing the role of carbon dioxide in the water through the reverse osmosis membrane to generate bicarbonate ions, aggravate the burden of mixed bed, affecting the operation, so set up the degassing tower to remove carbon dioxide.

2. The working principle of degassing tower

 Internal packing plastic multi-surface hollow ball, reverse osmosis water from the top of the spray down, the fan will be sent from the bottom of the air, the water flow through the plastic multi-surface hollow ball into a thin layer of water, and air contact with carbon dioxide dissociation, to achieve the effect of removing.

3. The role of the intermediate water tank

 Storage of carbon dioxide removal of reverse osmosis water, set the level sensor, high liquid level automatically shut down reverse osmosis device and degassing tower, the intermediate level automatically start, low liquid level automatically shut down the intermediate pumps, the liquid level up to the intermediate level automatically start the intermediate pump.

V. Mixed-bed ultrapure water device

1. Mixed-bed ion exchange method principle

 It will be anion and cation exchange resin according to the volume and proportion of the same exchanger in the mixing, the formation of a myriad of anion and cation exchange resin staggered multi-stage compound bed. Salt anions and cations in water are exchanged by the resin through the exchanger to obtain high purity water. The anion and cation resins are mixed with each other, and the anion and cation exchange reactions are carried out almost simultaneously. The H+ produced by H-type exchange and OH- produced by OH-type exchange are combined into H2O molecules, thus eliminating the influence of ionic counter-reaction, and the exchange is complete.

2. Mixed bed regeneration method

 Adopts in vivo regeneration method, utilizing two kinds of resins with different specific gravity, and backwashing to separate anion and cation exchange resins, with the cation resin deposited underneath and the anion resin floating above. The cation resin is regenerated with hydrochloric acid (or sulfuric acid), and the anion resin is regenerated with caustic soda.