| 摘要 |
<p>PURPOSE:To efficiently make arsine harmless without leaking the arsine vapor to the outside by passing an arsine-contg. gas through an activated-carbon adsorption tower, purging the adsorption tower with an inert gas, and then introducing an oxygen-contg. gas into the tower to oxide the arsine adsorbed on the activated carbon. CONSTITUTION:The arsine-contg. gas A (raw gas) discharged from a semiconductor producing stage is passed through the adsorption tower 11 at the first stage to adsorb AsH3 on activated carbon and remove the AsH3, and the gas is discharged to the atmosphere from a check valve 15c. An inert gas B is passed through the adsorption tower 11 at the second stage to purge the combustible gases such as H2 remaining in the tower 11, and the discharged inert gas is discharged to the atmosphere through another adsorption tower 12. An O2-contg. gas C is passed through the adsorption tower 11 at the third stage to allow the adsorbed AsH3 to react with O2, hence the AsH3 is oxidized to As2O3, etc., and the gas is made harmless. Since the temp. of the adsorption tower is raised by the heat of reaction, the temp. must be controlled to <=about 200 deg.C during the reaction. The O2-contg. gas discharged from the adsorption tower 11 is discharged into the atmosphere through the adsorption tower 12.</p> |
