Timber drying kiln air circulation system - temp. controlled flap valve controls dry air feed and wet air discharge

摘要

The timber drying kiln employs a system of ducts with a control valve which includes a swinging flap actuated by a temperature controlled pilot operated mechanism to control the circulation of air inside the kiln. The whole system operates so that after the air has been heated, and becomes saturated with moisture, a controlled amount of moist air is extracted, and dryer air is fed in, mixed with the remaining moist air and the extracted portion is dried, heated, and fed in again, keeping the temperature constant. The dry air is ambient air. The duct system includes a moist air extraction duct, the duct to the air dryer, a dry air feed duct, and a duct communicating with free air.