Views: 17 Author: XICHENG EP LTD Publish Time: 2021-08-16 Origin: XICHENG EP LTD
Carbon dioxide remover is abbreviated as carbon remover. It is a device to remove free CO2 in water.
(1) The working principle of the carbon dioxide remover After the raw water is exchanged with hydrogen ions, almost all the cations in the raw water are converted into H+, and the effluent is acidic and contains a lot of water.
Away from CO2 gas. This is because the pH value of the effluent water is significantly reduced, which is conducive to the ionization balance of carbonic acid in the water to move to the direction of CO2$ H+ +HCO3 - =H2CO3 =CO2 +H2O, for example, for every `1mmol/LHCO3-, 44mg/L CO2 can be produced. When the pH value of the water is lower than 4.3, almost all the carbonic acid in the water exists in the form of free CO2. The free CO2 in water can be regarded as the gas dissolved in the water. According to the gas partial pressure law and Henry's law, as long as the partial pressure of CO2 on the water surface is reduced, the dissolved CO2 gas in the water can be removed. This is the working principle of the decarbonizer.
(2) Purpose of carbon dioxide removal (1) To reduce the corrosion of CO2 on the water supply system, condensate system and boiler; (2) In the hydrogen-sodium ion softening dealkalizing water treatment system, the parallel system is to eliminate the neutralization CO2 generated in the water; for the series system, a carbon remover is installed before the sodium ion exchanger to avoid the generation of NaHCO3 when the water containing CO2 passes through the sodium ion exchanger and the alkalinity of the soft water will increase again. (3 ) In the ion exchange desalination water treatment system, if the water after H-type cation exchange is first used to remove CO2 in the water with a decarbonizer, and then flows through the anion exchanger, the burden on the anion exchanger can be reduced and extended The working time of the anion exchanger also creates favorable conditions for the anion resin to adsorb silicate.
(3) Types of carbon dioxide removers There are two types of carbon removers commonly used: blast type carbon removers and vacuum type carbon removers.
Blow-type decarbonizer: The blast-type decarbonizer is mainly composed of a body, a filler, and an intermediate water tank. The body of the decarbonizer is made of metal or plastic treated with an anti-corrosion layer. The inner packing types include porcelain ring, honeycomb grid paper, Pall ring, polypropylene multi-faceted hollow ball, etc. The water enters from the upper part of the decarbonizer, is evenly drenched by the water distribution equipment, passes through the packing layer, and is discharged from the lower part into the intermediate water tank. The air used to remove CO2 is sent to the bottom of the carbon remover by a blower and is discharged from the upper part after passing through the packing layer in the carbon remover. In the decarbonizer, due to the blocking effect of the filler, the water flowing from the top is dispersed into many small strands of water, water or water film, so that the blown air and water have a very large contact area. Since the partial pressure of CO2 in the air is very small (about 0.03%’ of atmospheric pressure), the air will quickly take away the CO2 desorbed from the water. After passing through the blast-type decarbonizer, the CO2 content in the water can generally be reduced to less than 5mg/L .
Vacuum decarburized: It uses a vacuum pump or ejector to draw a vacuum from the upper part of the decarburized to make the water reach the boiling point to remove the gas in the water. This method can not only remove CO2 in the water, but also remove "# and other gases dissolved in the water, so it is also beneficial to prevent the oxidation of the exchange resin and the corrosion of metal equipment .