精对苯二甲酸装置粉料气输系统的扩能改造

Capacity Expansion for Powder Pneumatic Conveying Unit in Terephthalic Acid Purification Plant

利用气流输送试验装置对精对苯二甲酸(PTA)粉料进行稀相气流输送试验,得出了 PTA 粉料气流输送压降计算的数学模型及关键技术参数,并采用原 PTA 装置的生产数据,对该数学模型进行了验证。在中国石化上海石油化工股份有限公司 PTA装置由300 kt/a 扩大到400 kt/a 的扩能改造中,结合气源条件,对 PTA 粉料气输系统3种改造方案进行了模拟计算,选择出技术经济合理的改造方案。改造后,在气源压力0.190 MPa、输送总气量低于23 000 m^3/h 的条件下,4条气输系统均能满足输送能力52 t/h 的技术指标。

A terephthalic acid purification plant in Southern China with a capacity of 300 kt/a decided to increase its capacity to 400 kt/a. The relevant four line powder pneumatic conveying installation in the plant must be revamped according to the task. An industrial scale test for dilute phase pneumatic conveying of crude terephthalic acid and purified terephthalic acid powder was designed. Keeping the consideration of available conveying gas pressure, flowrate, powder amount to be conveyed and conveying distance the test was carried out aiming at establishment of a simulation model for calculation of pressure drop in the conveying pipe. Many measurements including gas pressure, flowrate and friction along the pipe, mass flowrate of powder, physical properties of powder, temperature etc were taken and collected. By regression of collected data from the test, critical parameters for the simulation model were obtained. By comparing the calculated data with actual data from an existing powder pneumatic conveying installation, the model was proved to be reliable. A reasonable and economical design plan issued from calculation for the revamping was chosen and was executed successfully. After revamping, each of four lines can meet the expanded conveying capacity of 52 t/h based on total flow rate under 23 000 m^3/h at 0. 190 MPa.