초록 ▼

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 t

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 changing over to a value within an allowable range.

대표청구항 ▼

A boiler air flow controlling apparatus of the type which includes a first fan for feeding air to a boiler, and a second fan for sucking air from said boiler, and wherein one of said first and second fans is driven by a variable speed electric motor the speed of which can be varied by changing the n

A boiler air flow controlling apparatus of the type which includes a first fan for feeding air to a boiler, and a second fan for sucking air from said boiler, and wherein one of said first and second fans is driven by a variable speed electric motor the speed of which can be varied by changing the number of poles in accordance with a load applied thereto, said boiler air flow controlling apparatus comprising means for providing, when the rotational speed of said variable speed electric motor for driving said one of said first and second fans is to be changed by changing the number of poles, to the other one of said first and second fans an air flow varying controlling instruction for varying an air flow of said other fan in advance of variation in air flow of said one fan.