BOILER AIR FLOW CONTROLLING APPARATUS

摘要

A boiler air flow controlling apparatus for feeding air in a desired air flow to a boiler by cooperation of a first fan for feeding air to the boiler with a second fan for sucking air from said boiler. The apparatus includes means for varying, when the number of poles of at least one of motors for the two fans is changed over, the opening of a damper located in an air course in order to restrict a variation of the inner pressure of the boiler upon such chaging over to a value within an allowable range.