SU931751A1 - Blast furnace air heater - Google Patents

Description

(54) DOMAIN FURNACE AIR HEATER

one

The invention relates to metallurgy, in particular, to the design of an air heater for a blast furnace, and can be used in all sectors of the national economy where high-temperature heating of low-calorie gas gases is required.

Closest to the proposed technical entity is a blast furnace air heater containing a casing, a refractory lining, a nozzle chamber and a combustion chamber, in the lower part of which an additional regenerative heat exchanger with a dome and a separating wall is located.

The heat exchanger consists of a nozzle chamber with a heated air inlet (hot air) and a steam burner, the hot air outlet fitting being connected by an additional pipeline to the gas burner of the air heater 1.

The disadvantage is that in the air heater a saddle separating wall between the chamber of the built-in heat exchanger and the chamber of the air heater nozzle is under considerable pressure during operation of the air heater on the blast. Under the influence of this pressure

The breakthrough of cold air into the chamber of the heat exchanger nozzle is not excluded, and the strength of the saddle wall and the heat exchanger dome is not ensured for a long time. The purpose of the invention is to increase the durability of the air heater and, as a result, increase the service life between repairs.

The goal is achieved by the fact that the blast furnace air heater holding the casing, the refractory lining, the nozzle chamber and the combustion chamber, in the lower part of which there is an additional regenerative heat exchanger with a dome and a dividing wall, The shells between themselves and the casing are made by means of compensators, the peripheral and separating walls of the heat exchanger along the entire height of the nozzle are articulated through partition walls with through channels, with annular cooling channels in the outer masonry of the dome.

Due to the implementation of the built-in heat exchanger in a gas-tight shell equipped with compensators, with a dividing wall, supported by spacer partitions, and air-cooled, this dome achieves an increase in durability of the air heater of the proposed structure, which allows to increase the efficiency of heating to blow.

FIG. 1 shows the proposed blast furnace stove, vertical section; in fig. 2 — node I in FIG. 1 (additional regenerative heat exchanger); in fig. 3 shows section A-A in FIG. 2

The blast furnace high-temperature air heater contains a casing 1, lining 2, chamber 3 of the nozzle and combustion chamber 4, in the lower part of which there is a regenerative heat exchanger 5 including a gas-tight wall 8, expansion partitions 9, a dome 10 and nozzle 11 located above the sub-nozzle 12. V through partitions 9 through channels 13 are provided for the passage of gases. The gastight shell 6 contains a horizontal part 14 above the dome of the heat exchanger 5, connected to the casing 1 and the vertical part 15 via wave compensators 16, necessary for ensuring the thermal expansion of the masonry of the peripheral and separation walls. The vertical part 15 is attached by side edges to the casing 1 along the entire height of the heat exchanger. An annular air-cooled channel 17 is provided in the outer masonry of the dome 10 to prevent overheating of the domed space. The inner shape of the dome 10 is formed by rotating the half-shaft around the horizontal minor axis (axis a-a in FIG. 3)

The heat exchanger is designed to work with the dome temperature up to 1200 ° C and air pressure up to 0.05 kg / cm. It works as follows.

The blast furnace gas and fan air are fed to the roof burner. Combustion takes place under the dome 10 of the heat exchanger, the combustion products pass through its nozzle 1 1, give it heat and go into the chimney. In the second period of operation, the combustion air enters through the air duct and the sub-nozzle 12 into the heat exchanger nozzle 11, passes through it, is heated and is fed through an additional duct to the main burner of the air heater.

The feature of the design of the heat exchanger is that it is loaded with a significant pressure of the blast air from the outside with a slight excess internal pressure not exceeding 0.05 kgf / cm. The main purpose of the expansion walls 9 is to improve the working conditions of the dividing wall 8, to drastically reduce the bending conditions in it and the deformations in the place of joining of the dividing wall 8 to the peripheral masonry 7.

The implementation of the heat exchanger 5 in a gas-tight shell b, equipped with compensators 16, with a dividing wall 8, supported by spacer partitions 9, and with a dome 10, equipped with an air-cooled channel 17, provides long-lasting structural strength and reliability of the proposed heater.

Thus, the application of the invention allows to increase the efficiency of heating to blow using low-calorie gases.

The expected economic effect due to the use of low-calorie fuel is about 208 thousand rubles.

Claims (1)

Invention Formula A blast furnace stove containing a casing, a refractory lining, a nozzle chamber and a combustion chamber, in the lower part of which there is an additional regenerative heat exchanger with a dome and a dividing wall, characterized in that, in order to increase the durability of the air heater and increase the service life between repairs, the heat exchanger provided with a gas-tight shell, covering the dome section and the dividing wall, while the shells are connected to each other and the casing is made by means of compensation Atorov, peripheral and separator walls of the heat exchanger along the entire height of the nozzle are articulated by spacer partitions with through channels, with annular cooling channels in the outer masonry of the dome. Sources of information taken into account during the examination 1. USSR author's certificate in application No. 2597005 / 22-02, cl. From 21 to 9/02, 1980.