Abstract:
A method of continuously feeding coal or the like to coal gasifier means or the like operating under a predetermined elevated pressure and of continuously removing ash or the like therefrom in which the coal feeding and ash removing procedures are interrelated to provide energy conservation by removing heat from the ash and transferring the heat to the coal, such energy conservation being performed by means of the liquid medium (water) used to feed the coal and remove the ash. In the coal feeding procedure, coal is continuously introduced into a first low energy water circuit from which successive volumes of coal particles and entrained water are transferred to a second high energy water circuit during which transfer the first circuit gains water from the second circuit, the second circuit includes a first liquid volume having a free liquid surface maintained at a high pressure level at or near the pressure level of the gasifier through which the coal is moved to supply the gasifier. In the ash removal procedure, a second volume of water having a free surface is maintained at the outlet pressure of the gasifier to receive the discharged ash therethrough, the second volume of water forms part of a third high energy water circuit from which successive volumes of ash and entrained water are transferred to a fourth low energy water circuit, the heated water from the second and third circuits after ash removal therefrom is utilized to supply the loss of water from the second circuit and the excess cool water from the first circuit is utilized to control and maintain, in conjunction with a fresh cool water supply, the temperature and level of the second volume.