Abstract: A steam generator and a method of burning fuels therein. A combustion chamber of gas-tight pipe walls has a fluidized bed. Above the bed is a free space with an incrementally lower solids density that accommodates heat-convection surfaces. Coarse-particle precipitators communicate with the top of the combustion chamber with their solids-extraction outlet communicating with the fluidized bed through a feedback system. The combustion chamber, its heat-convection surfaces, the coarse-particle precipitators, and the feedback system are surrounded by pressurized vessel. The fuel is burned in the fluidized bed under pressure. Densities of 0.5 to 5 kg of solids per kg of flue gas are maintained in the free space (4) above the bed by means of fluidizing rates of 1 to 5 m/sec. The temperature of and load on the fluidized bed are regulated by the amount of solids returned to the bed.

Abstract: A nozzle that consists of a pipe (4) with the end that extends into the treatment space surrounded by a hood (6) is employed to inject solids into a reaction space, a fluidized-bed combustion chamber for example, pneumatically. There are outlet bores (12) in the wall of the pipe (4) and below the lower edge of the hood (6). Inside the pipe (4) is an inner pipe (13) that is connected tight to pipe (14) above the outlet bores (12) and that creates in conjunction with the pipe (4) a space (14) for air to flow through. The air flowing through this intermediate space (14) and emerging from the outlet bores (12) ensures transverse intermixture of the solids inside the reaction space.