Air separation unit accessories

There must be enough smooth straight pipe sections before and after the flow orifice plate. The distance is 10 times of pipe diameter in front of the orifice plate and 5 times of the pipe diameter behind the orifice plate, and no factors affecting the measurement accuracy (such as pipe joint, etc.) are allowed. The inner surface of the pipe weld should also be ground smooth, and the gasket should not extend into the inner diameter of the pipe. And carefully check the installation direction of the orifice plate, do not install it in reverse. (judgment method: the small exit is the entrance, and the large exit is the outlet)

In the distillation column of air separation, the air is usually pre separated in the lower column, and then distilled into oxygen rich liquid air and pure nitrogen, and then further distillation in the upper column to obtain oxygen and nitrogen products. As a condensing evaporator connecting the upper and lower columns, the pressure nitrogen of the lower column is used to heat the liquid oxygen of the upper column. When the liquid oxygen is evaporated, the gas nitrogen is condensed. The two-stage distillation column can make oxygen and nitrogen products obtain higher extraction rate and higher purity. The working principle of single-stage distillation column is similar to that of the lower column of two-stage distillation column. Oxygen enriched liquid air is at the bottom of the column, and pure nitrogen gas can be obtained at the top of the column. The single-stage distillation column can't separate the air perfectly, so it is seldom used in practice. However, because of its simple