Energy-saving low-pressure extraction cold melamine production process

Abstract

The invention provides an energy-saving low-pressure extraction and cooling melamine production process, including a melamine reactor, a hot air cooler, a filter, a crystallizer, a trap, a carrier gas compressor, a cold air fan, a urine scrubber, a carrier gas heater, etc. . The upper part of the crystallizer has a double-layer cold air ring pipe, and the lower part of the crystallizer has a rotary scraper; the air intake of the carrier gas compressor and the air-conditioning fan are separated, the air intake of the air-conditioning compressor adopts hot process air, and the air intake of the air-conditioning fan adopts cold process air; From the outlet of the carrier gas preheater, a hot process gas is led out to distribute hot ammonia gas or superheated steam into the hot gas cooler and filter; the filters are set in series and parallel. The low-pressure extraction and cooling melamine production process device of the present invention has less construction investment, low consumption, high operating flexibility, high-grade product rate can reach 95%, and the continuous operation period of the device can reach more than 4 to 6 months.

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

Images