What are the dehydration steps of horizontal screw centrifuge?
The raw material water goes to the hydrogen chloride tower first, and the high-purity H2S acetylene gas is obtained at the top of the solid-liquid separator. The bottom water with the molar ratio of NH3 / H2S of (12 ~ 15): 1 enters the ammonia tower, and the low ammonia tower of the solid-liquid separator continuously produces the heat source from the reboiler, and the bottom water is the filtered water, High purity nitrogen dioxide is obtained from the overhead steam after refrigeration. In the horizontal screw centrifuge, part of the cooling liquid returns to the top of the ammonia tower for cold flow, so as to control the temperature of the top of the ammonia tower. In order to better discharge the H2S into the ammonia tower, the other part of the cooling liquid returns to the hydrogen chloride tower
Horizontal screw solid liquid separator
1.When the raw material water comes to the ammonia tower, the filtered water is obtained from the bottom of the tower, the filtered water is obtained from the bottom of the horizontal screw centrifuge tower, and the high purity nitrogen dioxide is obtained from the overhead steam body after refrigeration. As in the above steps, a part of the cooling liquid returns to the ammonia tower as the cold flow, and the other part of the cooling liquid is used as the feed of the dust collector. Most of the bottom water of the H2S stripping tower is removed and still returns to the ammonia tower, In order to ensure that the molar ratio of NH3 / H2S in the total feed of ammonia tower (i.e. the sum of raw material water and bottom water of hydrogen chloride tower) is 4:1, and ensure the purity of nitrogen dioxide.
2.According to the ultra-low temperature charging, gas-liquid equilibrium, the molar ratio of NH3 to H2S and CO2 is controlled to exceed 4 ~ 6, so as to improve the solubility of H2S and CO2 in aqueous solution, and maintain the partial pressure circuit of NH3 in gas phase. The gas phase with high-performance liquid phase is nitrogen dioxide with high purity.


3.The whole tower of horizontal spiral solid-liquid separator is pressurized and the side line is extracted for processing. It is heated by reboiler at the bottom of the tower, and the cold feed is pumped from the upper end of the tower, so that NH3, H2S and CO2 in the feed acid-base water are subject to high temperature stripping from top to bottom and digestion and absorption from top to bottom, When the vapor is extracted from the middle opening of the tower, the partial pressure circuit of the gas phase is reduced and the gas phase equilibrium is destroyed, the NH3 in the high performance liquid phase moves rapidly to the gas phase, which sets the standard for NH3 to gather from the top to the middle and stripping from the bottom to the middle, In the middle of the tower, of course, there is a peak of NH3 concentration all over the tower. The ammonia rich vapor extracted from the middle side of the tower by the horizontal screw centrifuge through the whole process of high-temperature water separation and ultra-low temperature sulfur fixation, obtains high-purity nitrogen dioxide. The ammonia rich vapor extracted from the side line through the whole process of high-temperature water separation and ultra-low temperature sulfur fixation, obtains high-purity nitrogen dioxide.
4.The ammonia rich vapor from the side stream is 155 ° C is coming 120 ° C. 70% (volume) of the cooling water in the extracted gas can be discharged through the first stage condenser, the concentration of ammonia in the gas can be doubled, and the molar ratio of NH3 to H2S and CO2 can be increased to more than 10. The gas phase is divided into two stages, and the temperature is 70 ~ 90 DEG; C. The gas phase was then subjected to three-stage fractionation at 40 ° C. The working pressure is 0.12mpa. Under this ultra-low temperature pressure standard, the molar ratio of NH3 to H2S plus CO2 is already very large. According to the gas-liquid equilibrium, a small amount of acid-base components can be fixed in the high performance liquid phase, and then high purity nitrogen dioxide can be obtained in the gas phase.