Patent ID: 6938560
Filing Date: 2005-09-06
Classification: F23C,F23D,F23L

Abstract:
1. A solid fuel boiler comprising: a plurality of solid fuel burners each including a fuel nozzle spouting fuel and carrying gas therefore and an air nozzle spouting air; a furnace including a furnace wall to perform horizontal firing; a duct through which a part of combustion exhaust gas recirculates to said furnace from a downstream portion thereof: heat exchanger tubes disposed on said furnace wall and in a heat recovery area of said furnace; and a recirculation gas port via which the recirculation gas is supplied to a combustion region with a fuel rich part in the furnace, wherein said recirculation gas port is disposed between one of the burners that is positioned on an uppermost-stream side and an after air port, and is apart from an outer periphery of a throat portion (the most constricted portion) of the air nozzle in the one burner by 1.1 or more times a diameter of the throat portion.