Evaporative crystallization device for extracting ammonium salt by utilizing vapor recompression technique

Abstract

The invention relates to an evaporative crystallization device for extracting ammonium salt by a vapor recompression technique. The evaporative crystallization device comprises a charge pump, a preheater, a circulation pump, a crystallization tank, a crystal mush pump, a centrifuge and an evaporator; an outlet of the charge pump is connected with a solution inlet of the preheater; a solution outlet of the preheater is connected with an inlet of the circulation pump; an outlet of the circulation pump is connected with a solution inlet of the crystallization tank; a crystal mush outlet of the crystallization tank is connected with an inlet of the crystal mush pump; a crystal mush inlet of the crystallization tank is connected with an outlet of the crystal mush pump, and the outlet of the crystal mush pump is also connected with the centrifuge; the solution outlet of the crystallization tank is connected with a solution inlet of the evaporator; a solution outlet of the evaporator is connected with an inlet of the circulation pump. The evaporative crystallization device for extracting ammonium salt by utilizing the vapor recompression technique is characterized by also comprising a vapor compressor; an inlet of the vapor compressor is connected with a secondary vapor inlet of the crystallization tank; the outlet of the vapor compressor is connected with a vapor inlet of the evaporator; and the vapor outlet of the evaporator is connected with a vapor inlet of the preheater. Ammonium salt crystals are extracted by adopting the evaporative crystallization device, vapor is only required to be introduced at the initial running stage of the device; sufficient heat sources can be provided for the evaporator and the preheater during the subsequent evaporation process by utilizing secondary steam, and live vapor is not required to be introduced in again; the energy source consumption can be reduced effectively.

Description

technical field [0001] The present invention relates to an ammonium salt production equipment, specifically an evaporation and crystallization device for extracting ammonium salt using steam recompression technology (MVR), which can fully reuse the secondary steam generated during the crystallization process of ammonium salt solution. Thereby saving energy. Background technique [0002] As we all know, evaporative crystallization is the most important ammonium salt extraction process. The main process is to heat (generally use steam) saturated ammonium salt solution to evaporate a large amount of water in the solution, and the concentration is supersaturated to produce ammonium salt crystallization. Finally, through The crystal liquid separation device obtains the crystal product of ammonium salt. [0003] The traditional ammonium salt evaporative crystallization device includes a feed pump, a preheater, a circulation pump, a crystallization tank, a slurry pump, a centrifug...

AI Technical Summary

Problems solved by technology

However, since the secondary steam itself contains less heat, it loses heat almost completely after it heats the solution in the evaporator, so the evaporator can no longer provide steam heat source for the preheater. Connect the raw steam pipe to provide steam with enough heat for the preheater

Therefore, when this evaporative crystallization device is in operation, it needs to continuously feed raw steam to make the whole device operate normally, which consumes a lot of energy.

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