The evaporation crystallization process of ammonium potassium chloride has optimized the traditional process, and its characteristics are as follows:
　　(1) The process has a large capacity, the heat source is low-pressure saturated steam, and the final effect is vacuum operation, so as to reduce the boiling point of the solution, increase the driving force, design reasonable operating parameters and energy matching, reduce heat loss, and at the same time, configure a condensate preheater to increase the raw material temperature, thus achieving the purpose of energy saving and consumption reduction.
　　(2) Although the forced circulation evaporation crystallizer is widely used and has strong adaptability, it needs to weigh the operation cost and maintenance cost. First, we will equip the axial flow pump with a frequency converter, and adjust the motor speed of the axial flow pump by adjusting the frequency converter, so as to improve the efficiency of the pump, achieve energy-saving effect and reduce the running noise. Secondly, due to the high solid content of the three-way evaporation crystallizer, the internal structure of the three-way evaporation crystallizer is optimized, so that a small amount of solids in the solid-liquid mixture can be circulated within the effect, and the load of the axial flow pump is reduced. Thirdly, the pressure difference is used to transport materials, which reduces the electric load and is easier to operate.
　　(3) A liquid separator is arranged after the evaporation crystallizer is discharged, so that the concentration of the discharged liquid is increased, and part of the mother liquid is returned to the evaporation crystallizer, so that the heat exchange area of the crystallizer is reduced, and the indirect heat loss of the mother liquid is reduced.
　　(4) The liquid level of evaporators is automatically controlled, and the liquid level of each evaporator is controlled by the regulating valve on the feed line. The whole system of temperature, pressure and other instruments are transmitted to the control room, realizing automatic control, making the system operation simpler and the labor intensity of workers low.
　　(5) Forced circulation evaporation device adopts axial flow pump with large flow rate and low lift, and the reasonable flow rate in the pipe avoids the phenomenon of evaporator pipe blockage, but the high concentration ammonium potassium chloride solution is easy to block the process pipeline with the change of temperature, which affects the normal production. Therefore, we do steam tracing in the material discharge pipeline and the mother liquor pipeline, and the mother liquor tank is equipped with steam coils, and reasonable process piping and steam purging are set up to deal with the pipe blockage problem, so that the production is smoother and the number of stops is reduced.
　　(6) Ammonium potassium chloride is very corrosive. Considering the comprehensive benefits, we adopt reasonable equipment materials, choose titanium evaporation crystallizer under the first-effect high-temperature operation, and choose dual-phase steel for the second-effect, third-effect and crystallizer at medium and low temperatures.