| 摘要 |
<p>PURPOSE: A self-cleaning vacuum purge system is provided to avoid exposing workers to hazardous chemicals, risking expensive downtime for the operation, or releasing toxic or noxious fumes into the environment. CONSTITUTION: A vacuum purge system is provided to protect a vacuum pump(10) from becoming flooded with liquid that on occasion is purged with vapors from process equipment. The liquid is trapped in a vessel and then evaporated and exhausted through the vacuum pump as vapor. Evaporation of trapped liquid is effected by reducing or stopping the purge stream to the trapping vessel while continuing to operate the vacuum pump, thereby reducing the absolute pressure within the vessel. Evaporation of liquid can also be effected by supplying heat to the trapped vessel, either in cooperation with or instead of the pressure reduction. Use of a programmable logic controller enables a cyclic operation that traps(11) liquid from entering the pump, removes the trapped liquid as vapor, and then resumes normal purge operation.</p> |
