Why should the operating temperature of the clarifier be maintained at 80-90°C?
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Why should the operating temperature of the clarifier be maintained at 80-90°C?
When tar is lower than 60 degrees, its fluidity becomes poor, and tar and tar residue are difficult to separate. The general temperature is around 80 degrees.
The dehydration of tar is directly affected by the temperature and the fixed ammonium salt content in circulating ammonia water. At 80~90℃ and the fixed ammonium salt concentration is low, tar and ammonia water are easier to separate. Therefore, in an independent ammonia-water separation system, the degree of dehydration of the gas collector tar is poor. When the mixed ammonia-water separation process is used, the degree of dehydration of the mixed tar is better. However, only one step of clarification and separation still cannot achieve the required degree of dehydration. It must be further dehydrated at 80~90°C in the clarification tank.
1# Oxygen tar dehydration is directly affected by temperature and the content of fixed ammonium salts in circulating ammonia water. At higher temperatures (80-90°C) and when the concentration of fixed ammonium salts in ammonia water is low, tar ammonia water is easier to separate.； Another point is that the cooling of gas mainly relies on the evaporation of ammonia water. The temperature of circulating ammonia water is higher, and the evaporation of ammonia water is large, which can cool the gas well. When the temperature of the clarification tank is controlled at 80-90°C, the spray temperature of ammonia water cooling gas is about 75°C. This temperature is about 5-10°C higher than the dew point temperature of the gas to ensure the driving force of ammonia water evaporation.
It is not necessary to control the temperature of the clarification tank. Usually, the temperature of the tar storage tank is controlled to facilitate dehydration.
It is beneficial to the separation of tar ammonia water mixture and ensures the appropriate process temperature for spraying ammonia water in the air collecting channel.