| Summary: | 碩士 === 國立臺北科技大學 === 能源與冷凍空調工程系碩士班 === 101 === In recent years, domestic semiconductor industry is developed vigorously, cleanroom technology proceeded fast, linked with the related surrounding equipment and consumed materials that paid attention broadly. Early used clean platform to design treated material protection to avoid contamination and did not protect personnel. These clean platform could not treat infectious disease vector, therefore the staff will expose in the infected risk.
Isolators is the most important basic security protection for biotechnology plant, the working environment isolated hazardous compounds of the air is an important security considerations, and related to air tight and leak of the isolator that serious threat to the security of the staff and the working environment.
This study conducted two different leak test of side recirculated air isolator, (1) particles leak test, particle number of background environment of the isolator rose, then the isolator extracted at different negative pressure to calculate particle leak; (2) SF6 trace gas leak test, distributed sampling at inside and outside of the chamber to measure leak concentration change of the chamber at different positive and airflow; (3) leak test of pressure decay, compared the completed and uncompleted welding of the isolators. Firstly, sealed air outlet and return air of the chamber, threw dry air into the chamber to promote the internal pressure four times of the normal working pressure, compared the leak rate to the relate time change. In the experiment results: (1) side recirculated air isolator measured particle leak between -18Pa and -25Pa, leak ratio are 30~34%; (2) SF6 trace gas measured leak at 0.61m/s, 0.51m/s, and 0.41m/s air velocity, leak ratio are 7.8%, 5.9%, and 3.8%, respectively. From the above mentioned two different test methods, particle test detected leak while quick and easy, but its leak value is not only leakage value from outside of the chamber, and also came from the filter and returned the accumulated particles, therefore leak ratio is more larger, and; although SF6 trace gas leak test spent more time, but it had high sensitivity and accuracy. Leak quantity would be affected by air velocity and the pressure, leak concentration acted as sterilization phase of isolator that would result in concentration distributed nonhomogeneous phenomena, concentration distributed from outside of the chamber can be acted as leakage diffusion situation of contaminants leak. (3) leak test of pressure decay to compared completed and uncompleted isolator, spent time is five times from initial pressure descend to final pressure, the leak quantity had four times difference, leak area also had nearly 4.5 times. According to ideal gas equation, the temperature and pressure of the chamber need to keep constant that would effective of reduce leak quantity effectively.
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