Abstract: A method and an apparatus for controlling an amount of air of a gas boiler are disclosed. Detecting section detects a flame voltage of the gas boiler to output a flame voltage value signal which represents a flame voltage value. An air supplying fan supplies air into the gas boiler. A sensing section senses a rotative velocity of the air supplying fan to output a sensing signal which represents a present rotative velocity of the air supplying fan.

Abstract: A fuel-fired water heater has a combustion chamber disposed above a wall ucture forming a flow path for combustion air being drawn into the combustion chamber during firing of the fuel burner portion of the water heater. A combustion air shutoff system is incorporated in the water heater and functions to sense an undesirably high firing temperature in the combustion chamber and responsively shut off essentially all further air flow to the combustion chamber and thereby terminate combustion therein. In various disclosed embodiments thereof, the combustion air shutoff system includes a damper member movable between an open position in which its permits air flow through the combustion air flow path, and a closed position which it blocks essentially all further air flow through the combustion air flow path. The damper is releasably held in its open position by a eutectic metal fusible link member positioned exteriorly adjacent an exterior wall of the combustion chamber.

Abstract: An apparatus includes a boiler for receiving water from a water feed pipe and heating the water into steam and a condenser for condensing the steam into condensate. The condensate is fed back to the boiler through the water feed pipe. A solute source includes a solute which has at least one of oxygen, hydrogen peroxide and ozone. Generating member generates an aqueous solution by dissolving the solute supplied from the solute source into water. Supplying member supplies the aqueous solution to the water feed pipe to form a protective film made of iron oxide on an inner surface of the water feed pipe.

Abstract: A steam power plant for generating electric power has a fossil-fuelled boiler, a water-steam cycle for generating high-tension, superheated steam for a steam turbine, an economizer to transmit heat from flue gas to the feed-water, an air preheater to transmit flue gas heat to fresh air and devices for removing dust, sulphur and possibly nitrogen from the flue gases. In order to optimize heat exchange in the air preheater during operation and reduce the heat loses during start-up of the steam power plant, a heat exchanger system is provided with sections through which recirculated air and a heat vehicle medium flow, in which the section carrying the air is connected on the intake side to the fresh-air outlet of the air preheater and on the outlet side to the fresh-air intake of the air preheater.

Abstract: In a steam generating boiler having a bottom wall supporting a char bed and sidewalls with ports through which air is admitted for combustion of combustible species in the char bed and emanating therefrom, combustion is improved by introducing an oxygen-containing gas into a lower central zone of the boiler, from at least one point remote from the sidewalls to thereby cause intimate mixing of the oxygen contained in the gas with the combustible species.

Abstract: 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.