Sulfur Daily Question, April 5------5 rewards for participation, 10 rewards for correct answers

It is generally controlled by the top air cooling and the reflux tank in the downstream section

The top pressure is related to the bottom temperature, the top reflux, and the feed temperature; in simpler terms, it is mainly related to the heat load. The tower top pressure should be determined as high or low; high pressure is generally 0.5 MPa, while low pressure is usually 0.15 MPa.

How is the top pressure of the acidic water stripping tower controlled? Or what range should the tower top pressure be controlled within? As long as the pressure of the acidic gases at the top of the tower meets the requirements of the downstream sulfur recovery unit or incineration nozzles, the pressure can be as low as 0.05 MPa. Some acidic stripping units require ammonia recovery, and generally a higher pressure is needed; a pressure of 0.5 to 0.7 MPa is usually sufficient. This is because high pressure helps increase the relative volatility of hydrogen sulfide and ammonia. This allows hydrogen sulfide to be separated from ammonia; otherwise, if the designed operating pressure cannot be achieved, the number of theoretical plates required will increase, or ammonia will mix into the hydrogen sulfide gas, reducing the efficiency of ammonia recovery and also complicating the operation of downstream sulfur recovery units. This is the same for high-pressure single-tower ammonia extraction with side streams, as well as for two-tower high and low-pressure gas stripping of hydrogen sulfide in ammonia plants. Once you understand this principle, it’s not hard to figure out how to control pressure.

The top pressure of the acidic water stripping tower is required to be controlled at around 0.5 MPa

The pressure at the top of the tower is kept between 0.35 and 0.45 MPa; during normal operation it is around 0.38 MPa. If this pressure is too high, the stripping effect is poor

The level of tower pressure is related to the bottom temperature of the tower, the top reflux, and the feed temperature. When the top temperature remains constant, for the same raw water, changes in the top pressure affect the composition of the gas phase at the top of the tower. If the vapor-phase equilibrium pressure at the top of the tower increases, the concentration of hydrogen sulfide in the vapor phase will increase ； Conversely, if the equilibrium pressure of the vapor phase at the top of the tower decreases, the concentration of hydrogen sulfide in the vapor phase will decrease as well. Since the bottom temperature of the tower is determined by the bottom pressure, the quality of the purified water and the quality of the acidic gas are generally controlled by adjusting the top temperature through measures such as changing the stripping load, the side draw ratio, the hot and cold feed ratios, and the flow rate of acidic gas. The top pressure is 0.49–0.50 MPa.

The level of top pressure is related to the bottom temperature, top reflux, and feed temperature; generally, a pressure of 0.5 to 0.7 MPa is sufficient

How is the top pressure of the acidic water stripping tower controlled? Or what range should the tower top pressure be controlled within? As long as the pressure of the acidic gases at the top of the tower meets the requirements of the downstream sulfur recovery unit or incineration nozzles, the pressure can be as low as 0.05 MPa. Some acidic stripping units require ammonia recovery, and generally a higher pressure is needed; a pressure of 0.5 to 0.7 MPa is usually sufficient. This is because high pressure helps increase the relative volatility of hydrogen sulfide and ammonia. This allows hydrogen sulfide to be separated from ammonia; otherwise, if the designed operating pressure cannot be achieved, the number of theoretical plates required will increase, or ammonia will mix into the hydrogen sulfide gas, reducing the efficiency of ammonia recovery and also complicating the operation of downstream sulfur recovery units. This is the same for high-pressure single-tower ammonia extraction with side streams, as well as for two-tower high and low-pressure gas stripping of hydrogen sulfide in ammonia plants. Once you understand this principle, it’s not hard to figure out how to control pressure.

The top pressure is maintained between 0.35 and 0.45 MPa; during normal operation it is around 0.38 MPa. If this pressure is too high, the stripping effect becomes poor. The temperature at the top of the tower is in the 30s, while the temperature of the first tray is between 30 and 70 degrees. The temperature at the top of the tower does not get too high and remains quite stable. When steam pressure and temperature fluctuate significantly, it also affects the stripping efficiency of the tower. When both steam pressure and temperature are high, and when the temperatures at the bottom and top of the stripping tower are high as well as the pressure at the top of the tower, steam should be supplied first, but the reduction in flow rate should be gradual. When both the steam pressure and temperature are appropriate, an increase in the top temperature occurs; generally, increasing the cold feed has little effect. However, a significant increase in the cold feed is not conducive to the stable operation of the unit. In such cases, it is necessary to slightly reduce the pressure control valve for the acidic gases at the top of the tower, thereby decreasing the amount of acidic gases drawn off. It is possible to observe a noticeable drop in temperature at this point. Once the temperature reaches an appropriate level, usually around 30 degrees, the pressure control valve for the top of the tower can be gradually opened. Under normal conditions, its opening degree is around 72%. In addition to the main unit, our purified water is also supplied to the demineralized water station of the atmospheric pressure unit. Our side lines have always been in good condition; there haven’t been any problems with them~~