Progress in the application of cooling scrubber technology for large granular urea granulation tail gas

In the granulation section of the urea workshop of the chemical fertilizer plant, gas containing urea dust will inevitably be produced, especially in the granulation process of large particles of urea, dust gas with higher temperature and urea dust concentration will be generated. Dust is collected and recycled to increase economic benefits and avoid environmental pollution. According to the good water solubility of urea, wet capture technology is generally adopted at home and abroad, and the core device of the system is the urea exhaust gas cooling scrubber. Through this system, the exhaust gas produced by urea granulation is cooled and washed, and then discharged into the atmosphere, and urea dust is recovered at the same time. With the advancement of technology, the development of urea exhaust gas cooling and scrubbing equipment has gone through different stages. Including the original random packed tower, tray and nozzle combination, structured packing and MD tray composite structure, gas-liquid co-current cooling scrubber, etc. Compared with the traditional countercurrent absorption tower, the gas-liquid co-currentcooling scrubber. The operation will not produce flooding, the gas velocity range is large, the processing capacity is high, and the discharge is more environmentally friendly. Compared with the traditional scrubbing device, under the same conditions, the first investment is reduced by 40%, the system pressure drop is reduced by more than 50%, the fan power and air pressure are reduced, and the operation cost is reduced. In recent years, it has been adopted by most domestic manufacturers. © 2021, Chemical Industry Press Co., Ltd.. All rights reserved.