SU985049A1 - Blast furnace air heater - Google Patents

Description

 (3) DOMAIN AIR HEATER

one

The invention relates to ferrous metallurgy, in particular, to designs of air heaters for blast furnaces and can be used in other areas of technology where high-temperature heating of gases is required.

Known blast stoves containing a casing, refractory masonry of the walls and the bottom of the combustion chamber, a nozzle chamber, a burner, cold fittings and a hot blow 1 J.

A disadvantage of the known air heaters is the low resistance of the masonry of the combustion chambers.

The closest to the proposed technical solution to the technical essence and the achieved economic effect is a fireplace heater containing a casing, refractory lining of the radial and main partition walls, a burner, hot and cold choke fittings, a burning chamber and its bottom laying, in which an annular groove is made. connected vertical channels with a column located inside the bottom masonry, a lecturer connected to two external fittings for supplying a cooler 2.

A disadvantage of the known air heater is the insufficient efficiency and effectiveness of the aerodynamic protection of the masonry of the partition wall. In a known air heater, nozzles are installed at the bottom of the combustion chamber, through which coolant is supplied (for example, cold blast), which, washing the walls of the combustion chamber, protects them from heat from the products of heat. The gas / air mixture leaving the burner socket is fed perpendicularly to the partition wall washed by the coolant. In connection with this, in 2Q of this region the energy of the coolant jets will be intensely reduced, the gas flows will move and the effectiveness of protection of the masonry of the combustion chamber in the region of the separation wall will decrease. The purpose of the invention is to increase the efficiency and reliability of aerodynamic. protection of masonry burning chamber. The goal is achieved by the fact that 8 blast furnace heater containing a casing, refractory masonry of radial and separation walls, a burner, hot and cold fittings, a combustion chamber and lining of its bottom, in which an annular groove is made, connected with vertical channels to the inside lining of the bottom a manifold connected to two external fittings for supplying a cooler; the heater is additionally equipped with a dividing wall at a distance of 0.01-0.03 and a height of 0.5-1.0 from the arc length of the main separator noyIstenki, wherein the additional wall are placed along the buttresses with a distance between them equal to the length of the partition wall 0,12-0,20 arc. Under the average length of the separation wall understand the length of the arc along the axis of the wall.

FIG. 1 shows a blast furnace, vertical section; in fig. 2 shows section A-A in FIG. one.

The blast stove consists of a casing 1, on the inner surface of which there is a refractory lining 2, a chamber nozzle 3 and a combustion chamber k united by a dome 5. An annular groove 7 is opened in the bottom 6 of the combustion chamber M and opened inside the combustion chamber 4. The lower part of the annular groove 7 is connected by vertical pipes 8 to an internal collector 9 for supplying a coolant (cold blast). On the outer side of the casing 1 of the combustion chamber k, a collector 10 is installed, connected by nozzles 11 to an internal collector 9 for supplying a cooler. The external collector 10 is provided with a shut-off gate 12.

The combustion chamber C is separated from the chamber of the nozzle 3 by a dividing wall 13. At the bottom of the combustion chamber U, along the entire perimeter of the dividing wall 13, an additional wall T of high non-resistant material is installed between it 0.01-0.03 of the length of the dividing wall 13 (for example, MKV-72), forming a slit 15 - The height of the slit 15 is 0.5-1.0 of the average length of the dividing wall 13. Additional wall And from the side of the working space of combustion chamber A is held by buttresses (thrust walls) 16, which are spaced from each other

provides a protective sheath protecting the refractory masonry 2 and the casing 1 from the aggressive effects of gases with high temperatures in the flame. The cooler from the groove 7 adjacent to the dividing wall 13 first falls into the slot 15 and at the exit from it creates a protective sheath.

The proposed design parameters of the slit 15 and the buttresses 16 are explained as follows.

The width of the slit 15 should be 0,012-0,03 average length of the separation wall. If the minimum width of the cavity decreases, it is possible that the separator and additional walls will close together when the heater is heated.

At. Increasing the maximum value of the slit width decreases the working volume of the combustion chamber or the nozzle chamber, which will lead to the occurrence of pulsating combustion or a decrease in the heating surface of the nozzle.

The height of the slit 15 should be 0,, 0 the average length of the separation wall. The minimum value of the height of the slit is selected from the condition that its upper position is located above the axis of the burner socket. If this value is less, then the gas-air flow from the burner will turbulize and destroy the protective sheath from the cooler coming out of the groove adjacent to the separation wall. This leads to a decrease in the effectiveness of aerodynamic protection. The maximum value of the height of the gap is selected to the TC of the conditions

V

ECONOMY of refractory materials and this value should not exceed the length of the torch, because during periods of heating of the nozzle cold blast is used for a distance of 0.12-0.20 of the average length of the dividing wall 13 The stove works as follows. During all periods of operation of the air heater, a cooler, for example, a cold blast, is supplied from the external collector 10 with the open gate 12 through pipes 11 to the internal collector 9 and then through vertical pipes 8 into the lower part of the annular groove 7. Cold air blown from vertical pipes B ( nozzles), at the exit from the annular groove 7 adjacent to the masonry of the radial wall 2, burn the fuel in the upper part of the combustion chamber.

The need to install buttresses (thrust walls) next.

The additional wall is not 5 bearing, but it is fixed only along the edges in the masonry of the radial wall. Due to the different temperature conditions in the working space of the combustion chamber during periods of heating and thermal currents can blow in the additional wall, thermal stresses can be formed, leading to its deformation and destruction. Therefore, in order to strengthen it, it has been proposed to install the buttresses at a distance of 15 scientific research institutes each from 0.12-0.20 of the average dividing wall length. The minimum value of these values is selected from the conditions of saving refractory materials and with a further increase in the number of counterforts to 20, the useful volume of the lower part of the combustion chamber decreases, which increases its gas-dynamic resistance. When increasing, the distance between the buttresses (decreasing their number) will decrease the durability of the additional machine.

A technical and economic comparison of the known and proposed air heaters showed that the implementation of the latter in a blast furnace with an annual output of 1 million tons. cast iron will increase the resistance tabs of the combustion chambers on.

Claims (2)

1.Patent of France No. 2077706, cl. From 21 to 9/00, 1973. 2. USSR author's certificate according to the application N 288 8 / 22-02, cl. From 21 to 9/02 1979. fO ff q) uf.t