A kind of production device of synthetic urea

Abstract

The invention discloses a system for synthesizing urea. The system comprises a carbon dioxide storage tank, a carbon dioxide droplet separator, a carbon dioxide five-segment compressor, an oil removal and desulfurization tank, a medium pressure carbon dioxide heater, a dehydrogenation reactor, a medium pressure carbon dioxide cooler, a gas-liquid separator, a high pressure condenser, a liquid ammonia filter, a liquid ammonia buffer tank, a high pressure ammonia pump, a high pressure ejector, a urea synthesis tower, an overflow pipe, a high pressure scrubber, a circulating water cooler of the high pressure scrubber, a first-segment evaporation heater, a second-segment evaporation heater, a granulation tower and a tower top dust recovery device. The power consumption of the production device is reduced, and the total power consumption is reduced; in the synthesis process of the urea solution, the conversion ratios of carbon dioxide and ammonia are high, the residual unreacted carbon dioxide and ammonia can be circularly and sufficiently utilized, and the utilization rate of raw materials is close to 100%; since a circulating spray washing technology is adopted, the tail gas emission dust of the granulation tower of the treated urea is smaller than 5mg / Nm<3>, so that the dust removal efficiency is greatly improved.

Description

technical field [0001] The invention relates to a production device for synthesizing urea, which belongs to the field of chemical industry. Background technique [0002] Urea is a basic chemical product. my country is a large agricultural country and uses a huge amount of urea. The production capacity of urea is related to national agricultural and food safety. At present, the production processes adopted by large and medium-sized urea plants include: aqueous solution full circulation method, medium pressure combined urea method, carbon dioxide stripping method, and ammonia gas stripping method. [0003] Aqueous solution full circulation method: This method is adopted by most small and medium-sized urea plants in my country. The production process is mature, the operation is convenient and reliable, and the pumps and non-standard equipment are all domestically produced. It is characterized by a high conversion rate in the synthesis tower. Unreacted substances are decomposed ...

AI Technical Summary

Problems solved by technology

[0004] Carbon dioxide stripping method: Since the 1970s, my country has successively introduced more than a dozen sets of carbon dioxide stripping urea production units, most of which are large-scale units, which are characterized by short process flow, low synthesis pressure and low power consumption, but harsh operating conditions and corrosion It is more serious, the exhaust gas has the risk of explosion, and the operation flexibility is small

However, which method to use for dust recovery is affected by different tower types and different production processes.

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