RU2288279C1 - Oxygen converter gas-outlet circuit - Google Patents

Abstract

FIELD: ferrous metallurgy, namely gas outlet circuit of oxygen converter.

SUBSTANCE: gas outlet circuit includes main gas con, double-stage scrubber having hopper with hydraulic lock, smoke sucker, additional hood communicated through additional gas conduit with double-stage wet scrubber. Gas outlet circuit is provided in addition with system for dry removal of dust out of gas. Said system is in the form of elbow-separator mounted in turned zones of additional gas conduits with turning radius decreased from first elbow to last one and connected through pipelines with settling devices. First stage of scrubber is arranged horizontally. Additional gas conduit is opened to its upper wall. Second stage is arranged vertically. Main gas conduits before first stage of scrubber and additional gas conduit are provided with gas-tight valves. Hydraulic lock of hopper of double stage scrubber in the form of loop, its upper bending is arranged over level of draining opening of hopper.

EFFECT: enhanced reliability of gas exhausting without risk of explosion of gaseous mixtures.

2 cl, 2 dwg

Description

The invention relates to the field of ferrous metallurgy, in particular to the exhaust ducts of oxygen converters.

Known gas exhaust path of a steelmaking unit, including a converter gas cooler, wet gas purification, chimney and smoke exhaust. Such a gas exhaust path works with complete afterburning of exhaust gases (see Berezhinsky A.I., Zimmerman A.F. Cooling and gas cleaning of oxygen converters. - M .: Metallurgy, 1983, p. 11-12). The disadvantage of such a gas discharge path is the inability to capture the gases released during the filling of scrap and pouring cast iron into the converter.

The closest in technical essence and the achieved result is the gas exhaust path of the oxygen converter company "Baumko" (Germany). The layout scheme contains a converter, a caisson with an installation ring, a lifting gas duct, a wet two-stage vertical gas purification in one housing with a hopper and a water trap, an exhauster (smoke exhaust), a slurry pipe, rotary shutters, a measuring pipe, afterburners, a gas holder, an auxiliary umbrella connected by an additional gas duct with a wet two-stage gas purification and valve system (see Berezhinsky A.I., Zimmerman A.F. Cooling and purification of gases from oxygen converters. - M .: Metallurgy, 1983, p. 148).

The disadvantage of this technical solution is the possibility of explosive gas mixtures in the tract and even their explosion, as well as the low efficiency of gas cleaning from dust when cast iron is poured into the converter and the exhaust gas enters the sludge pipe. Inserting an additional gas duct into the vertical side wall of the wet gas purifier leads to moisture entering the gas duct, followed by dust settling in it until the section is completely blocked. When both valves are simultaneously closed, water overflows into an additional chimney, its overflow with water and possible collapse. Due to this, there is a decrease in the performance of the smoke exhauster with the occurrence of surging (unstable mode, accompanied by sharp fluctuations in productivity, power, body vibration, impeller shocks, etc.). Therefore, the valve on the main duct is always open (maximum closure 90%).

The occurrence of explosive gas mixtures in the duct is possible either by purging - when the valve is opened on an additional gas duct, or by casting iron in the case of using lump fuel (coal) to heat scrap metal in the converter. In the first case, gas flows through the main path with unburned СО of more than 12.5%, because it is blocked by atmospheric air flowing through an additional gas duct. In the second case, it is the other way around: the additional gas duct is ballasted with air passing through the main duct. Explosive mixtures may form at their mixing point.

The stream of water flowing out of the wet gas purification hopper through a water trap ejects toxic toxic gas and the resulting gas-liquid mixture enters the sludge pipe and then into the recycling cycle for cleaning.

The objective of the invention is to improve the environment by increasing the degree of purification of exhaust gases from dust and reducing emissions of harmful substances into the atmosphere, as well as increasing the reliability of equipment by eliminating explosions of exhaust gases during operation of the converter in the process of filling the charge, heating the scrap, cast iron and main blowing .

The task is achieved in that the gas outlet of the oxygen converter containing the main gas duct, a wet two-stage gas purification, including a hopper with a water trap, a smoke exhauster, an auxiliary umbrella connected by an additional gas duct to a wet two-stage gas purification, a valve system and a slurry pipeline, according to the invention, is additionally equipped with a dry gas purification system dust made in the form of elbow separators installed on bends of the additional gas duct, with a turning radius decreasing from the first elbow to the last, and connected by pipelines with precipitants, while the first stage of wet gas cleaning is located horizontally and an additional gas duct is connected to its upper wall, and the second stage is vertical, with the main gas duct valves in front of the first stage of wet gas cleaning and additional gas duct equipped with gas tight valves. In the gas outlet of the oxygen converter, the bunker wet gate of the wet two-stage gas treatment is looped, and its upper bend is located above the level of the bunker drain hole.

The technical essence of the invention is as follows.

Wet gas cleaning from two stages, the first of which is horizontal and the second is vertical, allows gas tight valves to be installed on the primary and secondary ducts, which in turn eliminates the leakage of cold air through the main duct when casting iron into the converter and prevents the formation of explosive gas mixtures . The supply of an additional gas duct to the upper wall of the first stage of a wet two-stage gas purification eliminates its filling with dust or water.

Installation of a dry gas purification system allows you to clean the gas from water-non-wettable graphite spell and soot before they get into a wet two-stage gas purification. Performing dry gas purification in the form of several knee-separators allows you to separate dispersed particles from gas with a high temperature of 450-600 ° C without additional energy costs, using the natural turns of the additional gas duct. Reducing the radius of rotation of the knee-separators from the first to the last knee increases the centrifugal forces acting on the particles in a curved flow and increases the efficiency of gas cleaning from dust.

The location of the upper bend of the hinged hydraulic lock above the level of the drain hole of the wet gas treatment hopper suppresses the process of ejection of a gas above the surface of the water with a water stream.

The technical result when using the invention is to increase the reliability of gas removal without explosions of gas mixtures, reduce the degree of knocking out of the gas torch into the atmosphere of the workshop when casting iron in the converter, improve the sanitary condition at the workplace and reduce the amount of particulate matter emitted into the atmosphere.

The proposed technical solution is illustrated by drawings, where figure 1 shows a layout diagram of the location of the device; figure 2-diagram of a loop valve.

The gas exhaust path of the oxygen converter 1 contains a main gas duct 2, a wet two-stage gas purification consisting of a horizontal stage 3 and a vertical stage 4, connected by an additional gas duct 5 to a smoke exhauster 6. An auxiliary umbrella 8 is located above the cast iron filling zone from the ladle 7, connected by an additional gas duct 5 to the upper the wall of the first stage 3 wet gas cleaning. A valve 9 is located on the main gas duct in front of the insertion point of the additional gas duct. On the additional gas duct 5, a valve 10 is installed, knee-separators 11, 12 connected by pipelines 13, 14 to precipitators 15, 16, respectively. There is a sludge pipe 17 in the gas exhaust duct and a wet two-stage gas purification contains bins 18, 19 with drain holes 20, 21 and loop locks 22, 23. The upper bends of the loop locks 22 and 23 are located above (at ΔН) above the drain holes 20 and 21 of the hoppers 18 and 19, respectively.

The exhaust pipe works as follows.

In the converter 1, steel scrap, lime and coal are heaped up. Open the valve 9 and close the valve 10. They put the converter 1 in a vertical position, turn on the oxygen supply and heat the scrap in the converter. The gases generated during coal combustion pass through the main gas duct 2, stages 3 and 4 of a wet two-stage gas treatment of horizontal 3 and vertical 4, a smoke exhauster 6 and are emitted through a candle into the atmosphere. After the heating of the scrap ends, the oxygen supply is stopped and an exposure is made to ventilate the exhaust gas duct. Then valve 9 closes and valve 10 opens. Converter 1 tilts and casting of pig iron from the ladle 7 to converter 1 begins. The gases formed with dust enter the auxiliary umbrella 8, additional gas duct 5. In the elbows-separators, graphite-containing dust is released from the gas stream. Larger dust is emitted on the knee-separator 11, fine on the knee-separator 12 and, passing through the pipelines 13 and 14, is deposited in the precipitators 15, 16. Then the gas enters the wet two-stage gas purification 3 and 4, the smoke exhauster 6 and is discharged into the atmosphere. After casting iron from the ladle 7, valve 9 opens and valve 10 closes. During purging, converter gases from converter 1 pass through the main gas duct 2, are cleaned of subliminal dust in a wet gas purifier 3 and 4, and are released into the atmosphere. Water with settled dust is collected in bins 18 and 19, passes through openings 20 and 21, loop water locks 22 and 23 and enters the sludge pipe 17.

The use of the proposed gas exhaust path improves the reliability of gas exhaust without explosions of gas mixtures, reduces the degree of gas flare knocking out into the atmosphere of the workshop when cast iron is poured into the converter, improves the sanitary condition at workplaces, and reduces the amount of dispersed substances emitted into the atmosphere.

The proposed gas exhaust duct is industrially applicable and used in steelmaking in an oxygen-converter shop.

Claims (2)

1. The exhaust path of the oxygen converter, comprising a main gas duct, a wet two-stage gas purification, including a hopper with a water trap, a smoke exhauster, an auxiliary umbrella connected by an additional gas duct to a wet two-stage gas purification, a valve system and a slurry pipeline, characterized in that it is additionally equipped with a dry dust gas cleaning system made in the form of knee-separators installed on bends of the additional gas duct, with a turning radius decreasing from the first knee to the last, and connected pipelines with precipitators, while the first stage of wet gas cleaning is located horizontally and an additional gas duct is connected to its upper wall, and the second stage is vertical, the main gas duct in front of the first stage of wet gas cleaning and an additional gas duct equipped with gas tight valves. 2. The gas exhaust path according to claim 1, characterized in that the bunker wet gate of the wet two-stage gas purification is looped, and its upper bend is located above the level of the hopper drain.

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