SU711332A1 - Fluidised-bed furnace - Google Patents

Description

The invention relates to the thermal and physicothermal treatment of fine-grained materials in a fluidized bed. A fluidized bed furnace is known in which the afterburning of combustible gases and coke dust is carried out directly above the fluidized bed by supplying a secondary blow through two rows of nozzles to the second stage of the furnace 11). However, with such an organization of the process, the operation of both stages is interconnected, which makes it difficult to control the process and is a disadvantage of a single-chamber furnace with a bale layer. A fluidized bed furnace is also known, which includes a heating chamber, around the perimeter of which a cordless peripheral air slot is made along its side walls 2. Uniform and effective processing of the material is possible only at a layer height equal to the diameter of the layer. The purpose of the invention is uniform processing and a decrease in the aerodynamic resistance of high material layers. The goal is achieved by the fact that the furnace is equipped with blowing nozzles installed on the side walls, which have additional chambers of equal static pressure, the nozzles being spaced from each other in height at a distance equal to half the diameter of the furnace. FIG. 1 shows schematically a fluidized bed furnace; in fig. 2 - Sechenko AA in FIG. one; in fig. 3 — node 1 in FIG. 1. The furnace contains a heating chamber 1, an equal static pressure chamber 2 with a distributor lattice 3 and an annular peripheral chamber 4, at the junction of which with the heating chamber there is a cordless slot 5. There are nozzles 6 around the perimeter and height of the heating chamber equipped with annular chambers 7 and inlet pipes 8. The furnace is equipped with inlet pipes 9 and 10. The furnace operates as follows. Air or the reaction gas through the inlet pipes 9 and 10 flows through the distribution grid 3 and the slot 5 into the fluidized bed zone, ensuring the formation of a fluidized bed of material. At the same time, air is supplied to chambers 7 of equal static

the pressure through the valves 8 and, distributed through the side nozzles 6, enters in the form of flat jets into the volume of the fluidized bed of the furnace along the side walls of the reactance chamber. The flat streams of air, rising from the slit 5, to a certain extent exclude the contact of the material with the walls of the heating chamber 1 and significantly reduce friction, which helps level the air velocity field in the cross section of the apparatus.

Over the entire height of the fluidized bed, air is additionally introduced into the chamber heater through the side nozzles 6, the design of which ensures that the air jet is attached to the surface of the side walls.

The selection of the distance between the blow nozzles in the side walls of the furnace is determined by the initial impulse supplied to the air blowing.

The distance taken is equal to 1/2 the diameter of the apparatus, which corresponds to the optimum value of the resistance of the layer of material in the fluidization technique. A decrease in this size causes an incomplete use of the kinetic energy of the air jet supplied for blowing, and an increase in the cost of additional blowing that is unjustifiable from an economic point of view, which leads to an increase in the cost of the entire material processing process in the fluidized bed furnaces.

Thus, the proposed design of the device makes it possible to save the kinetic energy of a flat annular jet over the entire height of the fluidized bed, provides

highly efficient processing of relatively high layers (from 1.5 and more diameters of the fluidized bed apparatus).

The proposed design of the furnace boiling

The layer provides a uniform and efficient processing of the material with an initial layer height of 1.5-5.0 diameters of the apparatus, which allows it to increase its productivity, as it grows directly in proportion to the height

spo processed material.

Claims (2)

Invention Formula The fluidized bed furnace, containing a heating chamber with a gapless perimeter around it, communicating with an equal static pressure chamber, characterized in that, in order to evenly process and reduce the aerodynamic resistance of high material layers, the furnace is equipped with additional equal static pressure chambers with built-in into the inner side walls of the heating chamber by blowing nozzles, the nozzles being placed apart from each other in height at a distance equal to half the diameter of the furnace. Information sources, taken into account during the examination 1. Cheese tnikov N. I., Volkov V. F. The processes in the fluidized bed. Sverdlovsk, Metallurgizdat, 1959, p. 21, Fig. 88 2. USSR author's certificate in application number 2399894 / 22-02, 16.06.77.