SU1709165A1 - Fluidized-bed furnace for heat treatment of grain materials - Google Patents

Abstract

The invention relates to the metallurgical industry and improves the efficiency of the furnace. The molding mixture is fed into the chute, which is heated by the torch of the side burners. Air to the formation of the fluidized bed is supplied through gas distribution caps placed on the grille inside the ring with inner and outer diameters of 0.4-0.5 D and 0.75-0.90, respectively, where D is the diameter of the chamber of the fluidized bed. 2 Il.

Description

The invention relates to devices for the heat treatment of granular materials and can be used in the metallurgical and other industries.

The purpose of the invention is to increase the efficiency of the furnace.

Figure 1 schematically presents a furnace, a longitudinal section; figure 2 - section aa in figure 1.

The furnace consists of a fluidized bed chamber 1, a settling chamber 2, a loading 3 and an unloading 4 leak, an air distribution grille 5 with caps 6, dead zones along the periphery 7 and in the center 8, side burners 9, and lining the furnace 10.

The furnace works as follows.

Spent molding or rod mixture is fed into the loading chute 3, through which the mixture enters the fluidized bed chamber 1. Air to bring the material to a boiling state is supplied through the air distribution grill 5 and the caps 6 to the fluidized bed chamber 1. The spent mixture under the influence of air goes into a boiling state and moves from the loading chute 3 to the unloading 4, heats from the torch of the side burners 9. At the same time, the spent mixture does not go along the shortest distance, i.e. not through the center, where the zone 8 is dead, but along a more elongated path, which increases its residence time in the furnace, and, consequently, the degree of burnout of the binder. The presence of a dead zone 1 on the periphery of the furnace near its walls leads to the fact that the jets of sand-air mixture near the caps 6, where their speed is especially great, do not affect the lining and do not wear it. In the upper part of the fluidized bed, air penetrates into the area of the dead peripheral zone 1 due to its small width, but its effect on the walls is considerably weakened. Thus, a narrow strip of the peripheral dead zone 7, although to a lesser extent than in the active zone, but participates in mass transfer and heat exchange, and at the same time significantly reduces the effect of air-sand jets on the furnace walls.

The flue gases resulting from burning the binder and burning the fuel in the burners initially have a high flow rate, however, filling the space above the dead zones, the flow rate drops and small particles of the material being processed settle.

In the proposed furnace, the presence of dead zones around the periphery and in the center of the air distribution grille allows to increase the durability of the lining of the furnace walls, reduce sand removal by reducing the flow rate of flue gases that fill the space above the dead zones.

The dead zones in this case partially replace the precipitation chamber and reduce its size. In addition, a reduction in sand flow reduces heat dissipation, i.e. increase the efficiency of the furnace.

Formula and invent

Fluidized bed furnace for heat treatment of granular materials, including a fluidized bed chamber, loading and unloading devices, a gas distributor cap grill and side burners, which, in order to improve the efficiency of the furnace, the gas distributor caps are placed on the grill only inside the ring with internal and

outer diameters, respectively (0.4-0.5) 0 and (0.75-0.9) 0, where O is the diameter, the chamber of the fluidized bed, and the furnace is equipped with a settling chamber.

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Claims (1)

Claim A fluidized bed furnace for heat treatment of granular materials, including a fluidized bed chamber, loading and unloading devices, a grill with gas distribution caps and side burners, characterized in that, in order to increase the efficiency of the furnace, gas distribution caps are placed on the grill only inside the ring with internal and external diameters respectively (0.4-0.5) D and (0.75 ~ 0.9) D, where D is the diameter of the fluidized bed chamber, and the furnace is equipped with a precipitation chamber. Suction FIG. 1 9 7 δ Figure 2