A Study on Improvement of White Smoke Reduction and Condenser Retrieval Efficiency of Photoresist Stripper Exhausting Systems in Optoelectronic Plants
Kam, Tai-yan Kam
|關鍵字:||Stripper製程;高效率過濾器;Stripper冷凝器;煙囪白煙;Demister;Stripper process, high efficiency filter, Stripper condenser, chimney white smoke, demister.|
Abstract TFT-LCD optoelectronic plants and semi-conductor plants are often troubled by the chimney white smoke. The general practice is to dilute or solve the issue of chimney white smoke by adjusting the operating parameters of the scrubber or treatment by a series of scrubbers (multi-phase processing and treatment). This approach is the end processing of pollution prevention equipment, which translates the air pollution problem into water pollution. In addition to the increase in equipment building cost and operating cost, it also increases the processing cost of wastewater equipment, and thus is not the optimum solution to the problem. At present, the exhausting of the photoresist stripping process in the TFT-LCD mostly relies on the condenser technology commonly used in semi-conductor plants to recover stripper. However, due to factors such as the increasingly larger-scale glass substrate and improving processing technology of the TFT-LCD industry, physical methods including high temperature, high pressure nozzle spreading are being used to strip photoreist rapidly. Such methods are different from the immersion and vibration process of semi-conductor industry. However, in the high temperature and pressure nozzle spreading process, there will be a large amount of smoke and mist in the exhausted fumes. Despite the condensation process by the condenser, there are problems like apparent white smoke presence in the exhaust gas ventilation pipes, poor stripper recovery rate, etc. The results of this study showed that, by source prevention management, namely, the installation of high density demister at the rear of the stripper condenser, the stripper in mist can be effectively blocked and collected by physical absorption. The proposed method can increase the retrieval efficiency of the stripper condenser, reduce NaOH usage in the stripper wet scrubber and the high COD processing burden of wastewater treatment, and even can considerably reduce the air pollution by the discharge of stripper containing gases.However, cost consideration is also important. The proposed demister can recover 3,000 liter/day stripper and save at least 648, 00,000 NTD each year. The equipment cost can be recovered within half a year. It is a solution to serve multiple purposes, and is worth implementation and promotion. Keywords: Stripper process, high efficiency filter, Stripper condenser, chimney white smoke, demister.
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