How do you control the liquid level in the absorption tower and the amount of vent gas from the first stage?

I. Control of the liquid level in the first absorption tower 1. Under normal operating conditions, the liquid level in the first absorption tower is primarily controlled by the rotation speeds of the Pump 1, Pump 2, and the ammonia water pump. Its main control principle is as follows: First, based on the system load and the temperature difference between the top and bottom of the urine tower, the speed of the Pump 1A is adjusted to remain within an appropriate range. The goal is to keep the temperature difference in the urine tower within a suitable limit; the lower the speed, the better, in order to minimize the water-to-carbon ratio inside the urine tower ； Secondly, the speed of the ammonia water pump is also controlled based on the system load and the load in the cleaning section of the first absorption tower. The control principle for the ammonia water pump is that, provided that the CO2 in the cleaning section of the first absorption tower can be completely absorbed, the lower the speed, the better ； The control range of the dimethyl pump should be wider; when the load remains constant, the rotational speeds of the methyl pump and the ammonia water pump remain relatively stable, while the rotational speed of the dimethyl pump changes depending on the liquid level in the first absorption tower. 2. The liquid level in the absorption tower is also related to the CO2 conversion rate in the urea tower. The higher the CO2 conversion rate, the less unreacted material there is; thus, less unreacted material enters the first absorption tower. With all other conditions remaining constant, the liquid level in the first absorption tower decreases ； Conversely, the liquid level in the absorption tower will rise. 3. The liquid level in the primary absorption tower is also related to the temperature of the primary heater. The lower the temperature of the first-stage heater, the lower the ammonium hydroxide decomposition rate and the total ammonia evaporation rate in the first-stage decomposition system; as a result, less unreacted material enters the first absorption tower. With all other conditions remaining constant, the liquid level in the first absorption tower decreases ； Conversely, the liquid level in the absorption tower will rise. 4. When production is not operating normally, adjustments can only be made based on the actual situation. II. Control of the first-stage vent volume 1. The size of the first-stage vent volume is related to the degree of CO2 conversion in the urine tower. The higher the urea tower conversion rate, the smaller the vent volume in Stage 1. Conversely, the larger the vent volume, the greater it is. 2. The amount of venting in a certain period is related to the purity of CO2 and the volume of air used for corrosion prevention. The higher the CO2 purity and the lower the amount of air used for corrosion prevention, the smaller the vent volume in Stage 1 will be ； Conversely, the larger the vent volume, the greater it is. 3. It is also related to the temperature of the one-degree heater. The lower the temperature of the first-stage heater, the lower the ammonium methoxide decomposition rate and the total ammonia evaporation rate in the first-stage decomposition system; as a result, less unreacted material enters the first absorption tower. With all other conditions remaining constant, the amount of gas discharged from the first stage will decrease ； Conversely, the vent volume will increase. 4. It is related to the washing and absorption efficiency of one absorption tower. The better the washing and absorption effect, the lower the amount of vent gas in one stage will be ； Conversely, the vent volume will increase. 5. It is related to the condensation efficiency of the medium-pressure ammonia cooling system. The better the condensation effect, the lower the vent volume for a given period ； Conversely, the vent volume will increase.