Structure of PSA nitrogen generator adsorption tower

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This post was last edited by Ameba on 2016-12-19 at 11:10. The adsorption tower is one of the key components in PSA nitrogen production systems, functioning primarily through pressure swing adsorption. Pressure swing adsorption is one of the gas purification processes. Its working principle takes advantage of the fact that the adsorption capacity of adsorbents for gases varies with pressure; by applying pressure, oxygen in the air is adsorbed and separated, while reducing the pressure allows the oxygen to be removed, thereby regenerating the adsorbent. As can be seen from its working principle, the adsorption tower, which is the device used to hold the adsorbent, must go through several key stages within a continuous cycle: adsorption, depressurization, pressurization, and final pressure increase. Therefore, the manufacturing quality of the adsorption tower equipment is directly related to the operating condition of the entire system. Taking into account the structural characteristics of the adsorption tower, Xinxiang Xincheng Petrochemical Machinery has adjusted the key manufacturing processes for conventional pressure vessels, and reselected the parameters for welding and heat treatment, thereby ensuring that the manufacturing quality of the adsorption tower meets the design specifications and relevant technical requirements – providing a solid foundation for its proper operation. Introduction to the adsorption tower of PSA nitrogen generation machines 1. Structural features of the adsorption tower in PSA nitrogen generation machines The adsorption tower is primarily composed of a cylinder, an elliptical head, a manhole at the top, flanges for connections at the bottom, and internal components. A schematic diagram of the adsorption tower in PSA nitrogen generation machines is shown below. In such towers, the inlet distributor adopts a conical sieve plate structure, with two layers of wire meshes of different specifications installed thereon. The connection structure between the skirt and the shell is crucial for the entire tower. In the design of XinCheng Petrochemical Machinery, skirt-type supports with excellent structural properties and minimal local stress at the connection points are employed. Design analysis of the adsorption tower in PSA nitrogen generators. Key technical parameters of the adsorption tower: design pressure of 1.87 MPa, design temperature of 65/–8°C; alternating pressure ranging from 0.03 to 1.6 MPa, with 63,000 cycles per year; the operating medium is purified coke oven gas. The shell material is Q345R (normalized), and the specifications can be adjusted according to customer requirements. The container is classified as category II. The operating pressure of the adsorption tower in Psa nitrogen generators remains in a fluctuating state, with a pressure range of 0.03 to 1.6 MPa; the number of pressure cycles per 24 hours can reach as many as 180 times. To this end, JB4732-1995 \"Steel Pressure Vessels – Code for Analytical Design\" must be adopted; a thorough analysis of the weak points is carried out based on the stress analysis reports, higher design stress strength values are specified, and the basic safety factor is reduced. However, the requirements regarding appearance, manufacturing, inspection, etc., are stricter compared to conventional designs. The shell and head materials of the adsorption tower equipment for Psa nitrogen generators are Q345R. When ordering these raw materials, their chemical composition and mechanical properties must not only meet the requirements specified in GB713-2008 \"Steel Plates for Boilers and Pressure Vessels\", but they must also be supplied in the normalized state. Ultrasonic testing shall be conducted on the edges of these materials, and low-temperature Charpy impact tests at -10°C shall be carried out in batches; the average impact energy Akv of the 3 test samples must be ≥24 J.