Removing contaminants from drying plant exhaust gas - where reheating removes organic deposits from heat exchanger

摘要

Combustible and depositable contaminants are removed from the exhaust gases from drying plant, e.g. for matchwood, by cooling the gases until the volatile materials condense and bind any entrained dust. The deposits are periodically revaporised and collected at a separate location for disposal, e.g. are deposited in filters which can be burned and used as fuel. Revaporisation may be by hot gas. The exhaust gas can be split into sepd. streams for the initial cooling, which may be by heat exchange with fresh air. The revaporisation can be initiated at a specific pressure difference between exhaust gases with and without the contaminating material. The process is suitable for matchwood mfr., and processes such as veneer drying and paint treatment which produce similar contaminants (terpenes, resins). Atmospheric pollution is reduced, and the risks and expense involved in previous burning-off methods are avoided.