Now the requirements for the quality of products produced by chemical companies are increasing. The effluent of ultrapure water equipment in chemical plants can be widely used. The effluent can be mainly used for chemical analysis, chemical materials, product cleaning, etc. This article will explain the solution of ultrapure water equipment in chemical plants. The best technical method is the combination of reverse osmosis and EDI.
Inlet parameters of ultrapure water equipment in chemical plant
source water city tap water, groundwater (water samples need to be tested), inlet water pressure>0.3MPa, inlet water conductivity <800us/cm. When the feed water conductivity is >800us/cm, it is recommended to use two-stage reverse osmosis. The design parameters are from 100 liters/day to 50 tons per day.
Chemical plant ultrapure water equipment process flow
The overall design plan of ultrapure water equipment in chemical plant
1. The first-stage pretreatment system: the quartz sand multi-media filter is used. The main purpose is to remove the sediment, rust, colloidal matter, suspended matter and other particles in the source water that are harmful to the human body above 20m. The system can automatically ( Manual) Carry out a series of operations such as backwashing and forward washing.
2. The second-stage pretreatment system: using nut shell activated carbon filter, the purpose is to remove the pigment, peculiar smell, biochemical organic matter in the water, reduce the residual chlorine value of the water, pesticide pollution and other pollutants harmful to the human body. The system can automatically (manually) perform a series of operations such as backwashing and forward washing.
3. The third-level pretreatment system: the use of cation resin to soften the water, mainly to reduce the hardness of the water, remove the calcium and magnesium ions (the main components of the formation of scale) in the water, which can effectively extend the service life of the reverse osmosis membrane, and Intelligent resin regeneration can be carried out.
4. The fourth stage pretreatment system: adopts a 5um pore size precision filter to further purify the water and optimize the turbidity and color of the water. Ensure the water inlet conditions of the RO system, ensure the quality of the water produced by the equipment, and extend the service life of the equipment.
5. Host of reverse osmosis equipment: Reverse osmosis technology is used for deep desalination treatment (imported US reverse osmosis membrane) to remove calcium, magnesium, lead, mercury and other harmful heavy metal substances and other impurities that are harmful to the human body, reduce the hardness of water, and the salt rejection rate reaches 99 % Above, to produce pure water that meets national standards.
6. Deionization host: The water treated by the first-stage reverse osmosis enters the pure water tank, and the pure water is pumped into the next-stage mixed bed through the pure water pump. The water quality out of the first-stage mixed bed is mostly less than 1us/ cm. If there is a higher requirement for water quality, it can be treated with a secondary mixed bed. The conductivity of the water after the secondary mixed bed treatment can be lower than 0.1us/cm, or even higher.
7. Microfiltration device: The installation of this device is mainly to prevent the particulate resin particles from filtering out of the cloth water, causing secondary water pollution, which is mainly used in occasions where the water quality is particularly high.
8. Sterilization system: Adopt ozone generator (or ultraviolet sterilizer) to reduce the secondary pollution of bacteria, and the sterilization rate can reach more than 99%. At the same time, ozone is dissolved in water to form oxygen-rich water to ensure the pure and fresh water. A water-gas mixer is used to fully mix ozone with water to achieve the best concentration ratio.
The effluent of ultrapure water equipment in chemical plants must meet national standards, and the most traditional ion exchange method causes serious pollution. The technicians of our company use the combination of reverse osmosis and EDI to prepare ultrapure water. Compared with the traditional process, this process has the advantages of low operating cost and reliable operation.