Sea water, salt water and circulating water from power plants all have the particularity of containing extremely high salt content, particularly chloride ions. Industrially, sodium hypochlorite solution is produced by electrolysis of chlorine ions using direct current.
Working principle
Sea water passing through the electrolytic cell is electrolyzed by direct current and the following reactions occur on the cathode and anode respectively:
Anode reaction:
< p>2cl--2e→cl2(1)
Cathode reaction:
2h2o+2e→ 2oh-+h2 ↑
(2)
Interelectrode reaction in an electrolytic cell:
cl2+
2naoh→2naclo+h2↑
< p>(3)Hypochlorous acid and hypochlorite are collectively called available chlorine. To prevent marine biofouling, effective chlorine produced by electrolysis of seawater
is used.
How does the watersalty, feed water and condensate water formed during power plant water treatment?
1. Ion exchange method: Use a specific cation exchange resin to use sodium ions for conversion. calcium and magnesium ions are replaced. The solubility of the sodium salt being very high, the formation of scale caused by the increase in temperature is avoided.
1. Characteristics and effects: the effect is stable and precise, the technology is mature, and the hardness can be reduced to 0.
2. Scope of use: Currently, the most commonly used standard method in catering, food, chemical, pharmacy and other fields, air conditioning, industrial circulating water and other applications.
2. Membrane separation method: Nanofiltration membrane and reverse osmosis membrane can intercepter calcium and magnesium ions in water, thereby fundamentally reducing water hardness.
1. Characteristics and effects: The effect is obvious and stable. Treated water has a wide range of applications. It has higher requirements for water inlet pressure and higher equipment investment. operating costs. .
2. Scope of application: Generally less used for specialized softening treatments.
3. Lime method: Add lime to water.
1. Characteristics and effects: Hardness can only be reduced within a certain range.
2. Scope of application: suitable for large flow of very hard water.
Desalinated water: After primary treatment with various filtration equipment to filter out tiny solid particles, large salt ion particles are removed by reverse osmosis (some are not), and finally by aanion and cation bed resin for ion exchange treatment. The result is pure water that doesn't even conduct electricity. Used as water replenishment to the unit condenser.
Water Supply: Once the condensed water is heated by the heater, it is boosted by the feed water pump. The supercharged water is called feed water.
Condensed water: After the steam has done its job, it is cooled and condensed into water in the condenser, called condensate water.