浆液法制备催化剂涂层自动吹扫设备及工艺

Automatic sweeping equipment and technology for preparing catalyst coating by slurry method

结构催化剂涂层常采用浆液法涂敷制备,但是,采用手工涂敷由于制备工艺差异大、可重复性差,导致制备过程中还存在涂层脱落、堵塞、涂层均匀性差、工业生产放大困难等问题。针对上述问题,文中设计搭建了一套自动化浆液吹扫装置,研究吹扫气流量、吹扫角度和气流移动速度等工艺参数对涂层负载量、脱落率和涂层一致性的影响。结果表明:研发的自动化吹扫设备及工艺有效提高了涂层涂敷过程的一致性和均匀性,气体流量逐渐增加,涂层的负载量与脱落率呈现下降的趋势。当气体流量为40 L/min,气流与丝网的夹角为90°,滑块的移动速度为600 mm/min时,制备得到的催化剂涂层的负载量为18.33%,脱落率(质量分数)低于2%,涂层表面平整光滑、无堵孔,综合指标优于文献现有报导水平,满足使用要求。开发的催化剂涂层自动化制备技术为丝网结构催化剂的工业化规模制备和应用提供了可行性。

Structural catalyst coatings were often prepared by slurry method.However,manual coating was used due to the large variation in preparation process and poor reproducibility,which leads to the problems of coating shedding,clogging,poor coating uniformity,and difficulty in industrial production scaling up during the preparation process.In response to the above questions,an automated slurry sweeping device was designed and built in this paper,and the influence laws of process parameters such as sweeping gas flow rate,sweeping angle and airflow movement speed on coating loading,mass loss and coating uniformity were investigated.The results indicate that the developed automated sweeping equipment and technics effectively improve the consistency and uniformity of the coating application process,and the coating loading and mass loss showed a decreasing trend with the gradual increase of gas flow rate.When the gas flow rate is 40 L/min,the angle between the gas flow and the screen is 90°,and the movement speed of the ram is 600 mm/min,the load capacity of the prepared catalyst coating is 18.33%,the mass loss is less than 2%,and the surface of the washcoat is flat and smooth without plug hole,which is better than the existing reports in the literature and meets the operating requirements.The automated catalyst coating preparation technology developed in this paper provides feasibility for the industrial scale preparation and application of screen structured catalysts,which is of great guiding significance.