Precautions for using the steam stripping first column in the full-cycle urea production process

It’s the same as operating a distillation tower, but be sure not to block the distribution holes in the lift pipe, otherwise it could cause corrosion and tube failure. The rest can be done according to the designer’s requirements. Filters are advisable to be installed on the inlet and outlet pipes of the stripping tower.

There are many details related to stripping, so caution is required

Corrosion control: Ensure an air supply of 2 m3 per turbin; strict control is applied to the quality parameters of the tube bundles, as well as to the manufacturing quality. Temperature and pressure parameters must also be strictly controlled. Equipment installation: Ensure the verticality of the equipment; a filter must be installed before the liquid enters the auto-stirred tank. The pressure difference between the pre-separated liquid and the liquid entering the auto-stirred tank should be at least 5 meters, while that for the U-tube should be at least 3 meters. Equipment manufacturing: The liquid film device, the verticality of the tube bundles, and proper compression of connections are very important.

Thank you, chengfr, for your encouragement. I will work hard to help us improve our auto-stripping technology together!

The small urea auto-stripping column was designed by Xiao Zhimin from the Fourth Research Institute of Chemical Engineering, based on the design of stripping columns used in the ammonia-stripped urea process. The first unit was put into operation in October 1998 at the Linquan Fertilizer Plant in Anhui; the original design called for the gas to be introduced into the stripping tower from the bottom of the stripper. After half a month of operation, the Linquan Fertilizer Plant increased its production from 250 tons per day to 450 tons per day, becoming the first to achieve the upgrade from model 6 to model 10. The second unit was put into operation at (current Haoyuan) in 1999, and later the Zhumadian Fertilizer Plant in Henan also adopted it. Later on, Engineer Xiao left the fourth institute and started working on his own; the fertilizer manufacturers he worked with included Shandong Shouguang Alliance, Shandong Dongping Ruixing, Shandong Pingyuan, Henan Xinlianxin, Hebei Dongguang, Chongqing Jiangjin, Hubei Dangyang, Anhui Fuyang No. 2 Fertilizer Factory, and others. The three facilities in Linquan and Fuyang in Anhui Province, as well as Zhumadian in Henan Province, were among the first to use this system. Apart from three pipe explosions at the Fuyang Fertilizer Factory during its initial operation period, and pipe explosions caused by corrosion due to blockages in the air supply pipes in Linquan, all three facilities have been functioning properly so far. Later, many of the manufacturers that used it encountered problems, some due to material issues and others due to installation issues. Based on experience, the following points should be noted when using a stripping tower: 1. The amount of secondary air added should be no less than 2 cubic meters per ton of urea. 2. The stripping tube must be installed in accordance with the specifications. 3. An inlet filter is installed to prevent debris from clogging the holes in the stripping tube. Of course, all process parameters must be followed as specified.