Abstract: A fuel supply duct, which supplies a mixed fluid of a solid fuel and carrier gas to one or more burners provided on the walls of a furnace, is provided with a branching part, and each of a plurality of branch ducts, which branch out from the branching part, is connected to a corresponding burner. Also a damper, with which the tilt angle with respect to the direction of flow of the mixed fluid can be changed, is positioned in the fuel supply duct at the upstream side of the branching part so that a mutual difference will arise in the solid fuel concentrations of the mixed fluid supplied to the respective branch ducts. A fuel distributor for fuel supply duct is thus arranged. The tilt angle of the above-mentioned damper is adjusted to increase the concentration of solid fuel in the mixed fluid supplied to a specific burner. At a burner to which the high solid fuel concentration is supplied, stability of ignition and stable combustion of the ignited flame can be obtained during low load operation.

Abstract: A fuel supply duct, which supplies a mixed fluid of a solid fuel and carrier gas to one or more burners provided on the walls of a furnace, is provided with a branching part, and each of a plurality of branch ducts, which branch out from the branching part, is connected to a corresponding burner. Also a damper, with which the tilt angle with respect to the direction of flow of the mixed fluid can be changed, is positioned in the fuel supply duct at the upstream side of the branching part so that a mutual difference will arise in the solid fuel concentrations of the mixed fluid supplied to the respective branch ducts. A fuel distributor for fuel supply duct is thus arranged. The tilt angle of the above-mentioned damper is adjusted to increase the concentration of solid fuel in the mixed fluid supplied to a specific burner. At a burner to which the high solid fuel concentration is supplied, stability of ignition and stable combustion of the ignited flame can be obtained during low load operation.

Abstract: A process for continuously and automatically producing a high concentration coal-water slurry having a uniform quality is provided, which process comprises always monitoring the viscosity, concentration, pH, particle diameter distribution and the like of the slurry, detecting the variations of the foregoing and adjusting the quantity of coal fed, the quantity of water fed and the quantities of a surfactant and a pH adjustor added to thereby control the specifications of the coal-water slurry to definite ones.

Abstract: A process for producing a coal-water slurry of low viscosity and high coal concentration with a low specific energy and a good efficiency is provided, which process comprises wet-grinding coal by means of a wet vertical ring-roll mill in the presence or absence of a surfactant and recycling a part of the coal ground by the mill, as it is, without classifying it, to the mill through a splitter.

Abstract: A process for producing a coal-water slurry having a high coal concentration (generally 60 to 80% by weight or more) and a lower viscosity, at a lower cost and with a smaller amount of dispersing agent added is provided, which process is directed to a process for producing a high concentration coal-water slurry by feeding coal, water and a dispersing agent into a wet, continuous ball mill and wet-milling them, characterized by feeding the dispersing agent in a multi-stage manner along the milling direction of coal within the ball mill.