Energy-saving low-pressure cold-brew melamine production technology

Abstract

The invention provides an energy-saving low-pressure cold-brew melamine production technology which comprises a melamine reactor, hot-gas coolers, filters, a crystallizer, a trap, a carrier gas compressor, a cool gas fan, a urine washer, a carrier gas heater and the like. The crystallizer is provided with a double-layer cool gas circular canal at the upper part, and a rotary material scraper at the lower part; gas inlets of the carrier gas compressor and the cool gas fan are separated, the gas inlet of the carrier gas compressor adopts hot process gas, and the gas inlet of the cool gas fan adopts cool process gas; a path of hot process gas is lead out from the carrier gas heater, and is matched with hot ammonia gas or superheated vapor, and the mixture gas enters the hot-gas coolers and the filters; the filters are arranged in series or in parallel. The device of the energy-saving low-pressure cold-brew melamine production technology is low in construction investment, low in consumption, and high in operating flexibility, the premium grade rate can reach 95%, and the continuous operation cycle of the device can be 4-6 months or more.

Description

technical field [0001] The invention relates to a melamine production process, in particular to an energy-saving low-pressure extraction and cooling melamine production process. Background technique [0002] Early domestic melamine production equipment generally had problems such as small scale, poor quality and high cost; in the 1980s, the domestic melamine market consumption continued to expand, and some production enterprises introduced the technology of Dutch DSM company, and 12,000 tons of melamine / year appeared Devices; In the 21st century, the domestic melamine industry has a device with an annual output of 50,000 to 80,000 tons of melamine. [0003] At present, the domestic melamine process has three mainstream processes: 30,000 tons / year low-pressure method, 50,000 tons / year low-pressure method and 50,000 tons / year high-pressure method. The main shortcoming of the low-pressure melamine process unit lies in the short operation period and high power consumption. The ...

AI Technical Summary

Problems solved by technology

The main shortcoming of the low-pressure melamine process unit lies in the short operation period and high power consumption. The main problems of the unit are: hot gas cooler heat exchange pipe blockage; crystallizer wall collapse blocks the discharge port; compressor impeller scarring ; Low product rate and high consumption (urea, electricity, catalyst, etc.)

The high-pressure melamine production process needs to pay high patent fees and large investment, which limits its popularization and application

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