RU1786085C - Furnace for thermally treating loose materials - Google Patents

Abstract

FIELD OF THE INVENTION The invention relates to the preparation of raw materials in the iron and steel industry, in particular to the reduction calcination of ground iron ores. SUBSTANCE: gas-tight casing and lining of the furnace working chamber are located with the formation of a cavity between them, covering the walls and the arch connected to the fan air supply system, the furnace being provided with a frame inside the gas-tight casing, in which the lining is fixed, having openings for passage of the valve thorn air to fittings. The gas tight casing is equipped with removable covers over the arch of the working chamber. 1 s.p. f-ly, 2 ill.

Description

FIELD OF THE INVENTION The invention relates to the preparation of raw materials in the iron and steel industry, in particular to the reduction calcination of ground iron ores.

The purpose of the invention is to increase the service life of the lining and to reduce gas and dust emissions from the furnace.

In FIG. 1 shows a furnace in cross section and a system for supplying fan air into the cavity between the lining and the gas tight casing; Fig. 2 is a unit for installing reinforcement for fastening the lining to the inner frame (section AA in Fig. 1).

The working chamber 1 has a reinforced lining of the walls 2, a suspended flat arch 3 and a crested hearth 4 with tuyeres 5. The lining of the walls and the arch with the help of reinforcement 6 is fixed in the frame 7 located inside the gas-tight casing 8. There is a cavity 9 between the gas-tight casing and the lining, connected with a fan air supply system consisting of a fan 10, a device for measuring the differential pressure 11, a regulator 12 with a control valve 13 mounted on the pipe 14 of the outlet of air from the cavity 9. In the places where the valve 6 is installed in the frame e 7 holes 15 are provided for air passage. The casing 8 has a removable cover 16 located above the vault 3.

The furnace operates as follows.

Under the influence of directed gas-air flows supplied through the tuyeres 5, the polydisperse material in suspension is subjected to heat treatment in the working chamber 1. The furnace gases formed during heat treatment, saturated with sulfur oxides, carbon oxides and aggressive dust, create excess pressure in the working space of the furnace under the influence of which they can penetrate through the lining leaks, leading to corrosion of the lining fastening reinforcement and pollution of the environment

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dy. In order to prevent leakage of furnace gases through the lining 2 into the cavity 9, air is pumped with a fan 10 at a pressure higher than the pressure in the working space of the furnace. The pressure drop in the cavity 9 and in the working chamber 1 is maintained at a predetermined level by the regulator 12 according to the signal received by the measuring device oj 11. The regulator 12 controls the valve 13 mounted on the outlet pipe of the air from the field 9. Fan air is supplied into the cavity 9 with a flow rate exceeding the gas permeability of the lining at a given pressure drop; excess air is discharged through the nozzle 14 and the valve 13, which ensures that the required pressure is maintained in the cavity 9. In order to better protect the reinforcement of the lining of the lining from the effects of aggressive furnace gases, openings 15 are made in the frame 7, which provide the supply of fan air from the cavity 9 directly to the places of installation of the reinforcement 6. Due to the presence of the air cavity 9 between the lining 2 and the gas tight casing 8, it becomes possible to overheat the frame 7 in the event of a failure in the supply of fan air (for example, in the absence of electricity). To prevent overheating of the frame, the gas-tight casing 8 is provided with removable covers 16 that open in case the fan air supply is cut off. At the same time, the valve 13 opens and, due to the natural traction, the frame 7 is cooled by the intake air.

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The use of this furnace allows, by filtering the fan air through the lining into the working space, to improve the conditions of its operation and to increase the service life, as well as significantly reduce harmful dust emissions into the environment.

Claims (2)

1. A furnace for heat treatment of a mixture of their materials, comprising a working chamber with a reinforced lining enclosed in a horizontal casing, and a comb bottom with tuyeres, characterized in that, in order to increase the life of the lining and reduce gas dust, a gas tight casing and the lining of the working chamber are located with the formation of a cavity between them, covering the entire surface of the outer surface of the walls and the arch, connected to a fan air supply system having a regulating body installed at the air outlet from the cavity, wherein the oven is provided with a frame disposed inside a gas-tight housing, wherein the lining is secured, and in the frame in the place of installation of reinforcement liner made fastening holes for the passage of the fan air to the valve. 2. The furnace according to claim 1, characterized in that, in order to prevent overheating of the lining fastening frame in case of interruption of ventilation air supply, the gas tight casing is provided with removable covers located above the working chamber arch.