RU2245373C1 - Blast tuyere for blast furnace - Google Patents

Abstract

FIELD: metallurgy; melting cast iron in blast furnaces.

SUBSTANCE: proposed blast tuyere has double-walled water-cooled body through which pipe supplying additional gaseous fuel is passed; blast tuyere is also provided with working channel. Said fuel supply pipe has two gas supply hoses whose attachments are brought out to working channel symmetrically relative to vertical axis of tuyere. Mechanical vibration generator is mounted at point of branching of pipe into two hoses or in each hose.

EFFECT: improved mixing of fuel with blast air.

3 cl, 3 dwg

Description

The invention relates to ferrous and non-ferrous metallurgy, in particular to the equipment of blast furnaces and other shaft furnaces, and is intended to supply gaseous additional fuel to the furnace furnace together with atmospheric or oxygen-rich blast.

Known blast tuyere of a blast furnace, consisting of a water-cooled housing with a flange and a gas supply pipe passed through the cavity of the housing, the outlet end of which is brought into the lance working channel at an angle opposite to the blast flow, and the cross section of the outlet end of the nozzle is made in the form of a gap [USSR Author's Certificate No. 368319, cl. С 21 В 7/6, 1970] and in the form of an elliptical pipe [Working drawing of the air lance of Severstal OJSC No. 071252-01 F].

The disadvantage of this lance is the unsatisfactory mixing of the injected gaseous fuel with the blast due to the low kinetic energy of the fuel flow, which does not provide fuel combustion in the near-tuyere space until it comes into contact with hot coke, on the surface of which hydrocarbon molecules that have not reacted with oxygen decompose into soot and hydrogen from significant heat costs (for methane, the heat cost for pyrolysis is 3340 kJ / m ³ ). As a result of this, the fuel efficiency and blast furnace smelting as a whole are reduced.

Mixing gas with blasting is complicated by the fact that the gas stream exits the nozzle into the tuyere channel at a low speed (about 25% of the speed of the blasting) and the blasting stream presses the gas against the cold surface of the inner tuyere cup. Gas, leaving the lance and rising upward, enters the reducing atmosphere, where it decomposes with the formation of soot and heat absorption.

Other solutions are known aimed at intensifying the mixing of fuel with blasting and burning the mixture. These include: a supersonic nozzle with a central element of the tuyere of a blast furnace [French Patent. Supersonic nozzle with a central element of the tuyere of a blast furnace. No. 2122682, cl. F 23 n 5/00], a lance with a curly insert [German Patent. Blasting lance with a curly insert, No. 195547], water-cooled lance of a blast furnace with guide ribs [French Patent. Water-cooled tuyere of a blast furnace with guide ribs, No. 2085511, class. C 21 V 7/00], the tuyere of a pulsating blast [Patent of England. Blast furnace with auxiliary tuyeres of pulsating blast. No. 1010655, cl. C 7 D], air lance of a blast furnace [USSR author's certificate. Air lance of a blast furnace, No. 477194, class From 21 V 7/16], where to improve the quality of fuel atomization, the ratio of the curvature of the nozzle sphere to the gap width is changed.

The main disadvantage of the known technical solutions is the difficulty of manufacturing and their failure when the blast furnace stops with a "pull".

Closest to the proposed technical solution is a blow lance, consisting of a water-cooled double-walled case with a flange, through the cavity of which a gas supply pipe is passed, the nozzle of which is a chamber with three holes, the axes of which are located at an angle to each other in the cross section of the lance. The central hole has a diameter larger than that of the side holes [USSR Copyright Certificate. Blast furnace tuyere lance, No. 908810, Discovery. Inventions 1982, No. 8, p. 98].

A disadvantage of the known solution is that the angles between the nozzle openings are 6 ° and therefore the gas flow is almost continuous, as in the solutions [USSR Author's Certificate No. 368319, cl. C 21 B 7/6, 1970; The working drawing of the air lance of OJSC Severstal No. 071 252-01 F] with low kinetic energy, which also does not provide efficient mixing of fuel with blast.

The technical result of the present invention is to improve the conditions for mixing gaseous fuel with blast and subsequent combustion of the resulting mixture in the tuyere space of the blast furnace without reducing the kinetic energy of both the gas stream and the blast stream.

The indicated technical effect is achieved by the fact that in the blasting tuyere containing a double-walled water-cooled body, through the cavity of which a pipe for supplying additional gaseous fuel and a working channel are passed, a pipe for supplying additional gaseous fuel is made with branching into two gas supply hoses, whose nozzles are brought into the working channel symmetrically with respect to the vertical axis of the lance, and in the place of branching of the pipe for supplying additional gaseous fuel two generators are installed mechanical vibrations, moreover, an elastic plate is mounted as a generator of mechanical vibrations, rigidly or freely fixed on a fixed axis from the gas supply side.

The device of the blowing lance is shown in figures 1, 2 and 3.

Figure 1 shows a section of a blasting tuyere of a blast furnace along the axis of the gas supply pipe, where:

1 - double-walled water-cooled body of the blowing lance;

2 - gas supply pipe;

3 - gas supply sleeve;

4 - nozzle gas supply sleeve;

5 - working channel of the blow lance of the blast furnace;

6 - generator of mechanical vibrations.

Figure 2 shows the placement node of the generator of mechanical vibrations (item 6 in figure 1), where:

2 - gas supply pipe;

6 - generator of mechanical vibrations;

7 - fixed axis;

8 - housing housing the generator of mechanical vibrations;

9 - holes in the housing 8, to which the gas supply hoses 3 are connected.

Figure 3 presents the blowing lance with the installation of the generator of mechanical vibrations in each gas supply sleeve, where:

1 - double-walled water-cooled body of the blowing lance;

3 - gas supply sleeve;

4 - nozzle gas supply sleeve;

5 - working channel of the blowing lance;

6 - generator of mechanical vibrations;

7 - fixed axis.

The blowing lance consists of a double-walled water-cooled housing (1), through which a gas supply pipe (2) is passed for supplying additional fuel, branching into two gas supply sleeves (3), nozzles of which (4) are brought into the working channel of the tuyere (5). At the branching point of the gas supply pipe (2) to the gas supply sleeves (3), a mechanical vibration generator (6) is installed on a fixed axis (7) in the housing of the mechanical vibration generator (8). The generator (6) is an elastic plate rigidly or freely fixed on the axis (7) from the gas supply side. The generator of mechanical vibrations can be installed both at the branching point of the gas supply pipe into two gas supply sleeves (3), and in each gas supply sleeve.

The work of the proposed blowing lance is as follows.

Through the working channel of the tuyeres, blast is fed into the furnace of a blast furnace, the velocity of which from the tuyere reaches 200 m / s or more, and gaseous fuel is supplied through a gas supply pipe (2) with a flow rate of up to 20% of the blast flow rate. The efficiency of blast furnace smelting substantially depends on the completeness of burning additional fuel in the oxidation center of the blast furnace, which, in turn, depends on the completeness of the process of mixing fuel with blasting, which is facilitated by the operation of a mechanical oscillation generator (6) located in a gaseous fuel stream. Since the gas flow velocity initiates oscillatory movements of the mechanical oscillation generator (6), the amount of gas entering through the openings (9) into each of the gas supply hoses (3) will change synchronously with the oscillations created by the generator (6). As a result, the gas flow in each exhaust pipe (3) will have a pulsating character and, upon exiting the nozzle (4), a more developed contact surface between gaseous fuel and blast. The latter will contribute to a more complete mixing of these reagents, and hence to a more complete combustion of the fuel, that is, high efficiency of blast furnace smelting.

Claims (3)

1. The blast furnace lance of the blast furnace, comprising a double-walled water-cooled body, through the cavity of which a pipe for supplying additional gaseous fuel is passed, and a working channel, characterized in that the pipe for supplying additional gaseous fuel is made with branching into two gas supply hoses, the nozzles of which are brought into the working the channel is symmetrical about the vertical axis of the tuyere, and at the branch of the pipe for supplying additional gaseous fuel to two arms or a gene is installed in each arm mechanical vibrator. 2. The blowing lance according to claim 1, characterized in that an elastic plate is mounted as a generator of mechanical vibrations, rigidly fixed to a fixed axis from the gas supply side. 3. The blowing lance according to claim 1, characterized in that an elastic plate is installed as a generator of mechanical vibrations, freely fixed on a fixed axis from the gas supply side.

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