New technology of applying double-effect forced circulation concentration method in production of ammonium phosphate

Abstract

The invention provides a new technology of applying the double-effect forced circulation concentration method in the production of ammonium phosphate, which comprises the steps of carrying out double-effect forced circulation flash distillation on phosphoric acid slurry, removing excess moisture in the phosphoric acid slurry and reacting with neutralizing slurry so as to generate intermediate slurry, enabling the intermediate slurry to be reacted with ammonia gas to generate a product, carrying out one-effect forced circulation flash distillation on the product slurry, further preparing qualified monoammonium phosphate slurry, drying and granulating by a fluid bed, packaging and weighing. Heat quantity generated by neutralization reaction is taken as a one-effect flash distillation heat source, and the excess heat in the one-effect flash distillation process is taken as a double-effect flash distillation heat source. With the adoption of the new technology, the heating steps in the production process are reduced, the quantity and height of devices used are decreased, heat energy is used reasonably, and energy consumption is reduced. The temperature difference between an inlet and an outlet of a heater is only 1-3 DEG C, degree of supersaturation can be controlled effectively, and scaling of the pipe wall of a heat exchanger is reduced. The forced circulation can enable the circulation speed of liquid phase to improve greatly, wash the wall pipe, and play an important role in reducing the scaling. The cycle of operation of a device is increased greatly, productive capacity is improved obviously, and the production cost is reduced effectively.

Description

technical field [0001] The invention relates to a process for producing ammonium phosphate, in particular to a new process in which a two-effect forced circulation concentration method is applied to produce ammonium phosphate. Background technique [0002] The degree of supersaturation is the driving force for the crystallization of the solute from the solution. The higher the degree of supersaturation, the faster the formation of crystal nuclei. At present, the domestic production methods of ammonium phosphate are mainly the traditional method and the slurry method. During the concentration process of these two production methods, there are many heating steps and the heating environment is complicated, and it is not easy to control the temperature. The more the temperature changes during production, the more the supersaturation changes. The more difficult it is to control, a large number of tiny crystal nuclei will easily form a scale layer on the tube wall, thereby blockin...

AI Technical Summary

Problems solved by technology

At present, the domestic production methods of ammonium phosphate are mainly the traditional method and the slurry method. During the concentration process of these two production methods, there are many heating steps and the heating environment is complicated, and it is not easy to control the temperature. The more the temperature changes during production, the more the supersaturation changes. The more difficult it is to control, a large number of tiny crystal nuclei will easily form a scale layer on the tube wall, thereby blocking the heat exchange tubes, resulting in a short operating cycle of the equipment during the production process and requiring frequent maintenance

Cause a lot of waste of manpower and material resources, virtually increase the production cost

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