RU2705753C1 - Blast-furnace casting bed aspiration system - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: invention relates to blast furnace casting bed aspiration system. System comprises ventilation gas outlets, local side suctions from cast iron and slag chutes, umbrellas over places of cast iron and slag drainage, automatic control system of aspiration system depending on phase of cast iron and slag discharge, throttle valves for controlling the system depending on the phase of cast iron and slag discharge, installed on the main and peripheral gas ducts from local suctions and umbrellas, aspiration emission filter, an exhauster with an automatic control system, an industrial vent pipe with a flare discharge, wherein the vented gas outlets of the aspiration system from sources of dust and gas emissions are located on metal structures outside the cast house, and local side suctions from iron and slag chutes are combined with supply air supply to zone of operation of local side suction with inflow fan with guide device operating in directions of iron or slag tap hole depending on outlet phase. Umbrellas above points of cast iron and slag are equipped with opening inspection windows for control of ladle filling process.

EFFECT: optimization of operation mode of the aspiration system, minimization of material costs for its implementation and power consumption during its operation, increased degree of aspiration gases cleaning.

1 cl, 4 dwg

Description

The invention relates to ferrous metallurgy, in particular to blast furnace production, and can be used in the construction of new and overhauls and reconstructions of existing blast furnaces, namely foundries.

Foundries of blast furnaces are the most powerful unorganized sources of air pollution at the enterprises of ferrous metallurgy. All sources of emission of pollution have a high temperature, therefore powerful convective air (gas) flows are formed above the heat sources, which rise to the upper zone of the foundry and are brown smoke (iron oxides), which is formed when air oxygen contacts the melt. The problems of creating effective aspiration systems are still relevant.

Known existing suction systems contain air ducts (gas ducts) located under the foundry yard, all equipment is closed with capacious shelters - arched covers, lined with refractory materials, from which air (gases) are sucked out, suction pipes above the main channel, skimmer and swinging channels, and gas ducts coming from the suction valves are equipped with shut-off valves that allow the system to work in a given mode, remove dust and gases only from that end of the pumping chute, where metal and slag are drained into buckets, och stka aspiration emissions produced on horizontal electrostatic precipitators. (Technical solutions to improve the efficiency of aspiration of foundries in blast furnaces, V.T. Stefanenko and others. Bulletin “Ferrous metallurgy”, No. 10, 2018, pp. 82-86).

The disadvantages of the known aspiration systems are:

- the used side suction from the place where the metal is released from the tap hole cannot cope with the removal of dust and gases, a powerful convective stream of emissions rises along the entire length of the uncovered part of the main groove into the upper part of the casting yard without cleaning;

- lateral suction does not provide effective aspiration of heated dust and gas emissions, due to their mismatch with the direction of the convective jet;

- long sections of horizontal sections of air ducts contribute to the deposition of dust in them, which reduces the rate of absorption of dust and gas emissions, and also leads to their abrasive wear;

- visual control of the free flow of metal and slag is difficult.

Known aspiration system of a casting yard of continuous operation for localization of suction of gases and dust generated during the production of pig iron and slag from a blast furnace. The system provides suction from the slots for the production of cast iron, including the section of the main groove adjacent to the furnace, from the places of drainage of cast iron, from the shelters of the main groove in the area of the skimmer, slag gutters. To adjust the operating mode depending on the release of cast iron, throttle valves are installed on one or another inlets in the duct network. The exhaust system is provided by smoke exhausters installed on the exhaust station (Aspiration system of a blast furnace workshop. M.Yu. Sukhanov, A.D. Ukhov, Yu.I. Kosenkov, M.A. Skshidlo, Metallurg, No. 6, 2005, p. 39- 40).

The disadvantages of this aspiration system are:

- to ensure the efficiency of dust collection, a significant increase in fan power and performance is necessary;

- visual control of the free flow of metal and slag is difficult.

A blast furnace foundry is known, containing transport chutes, swinging chutes, skimmers, an aspiration system in the form of umbrellas and side suction from dust and gas sources and ventilation ducts located on the first floor of the foundry’s base, a fan with automatic capacity control ranging from 300,000 to 900,000 m3 / hour depending on the phase of issue (RF Patent 2270256, pr. 05.21.2004, Mcl. C21B 7/14, publ. 02.20.2006 bull. No. 5). The known device is the closest in technical essence to the proposed aspiration system of the foundry of a blast furnace and is taken as a prototype.

The disadvantage of this design of the suction system of the foundry is:

- the difficulty of laying ventilation ducts on the ground floor of the foundry base;

- to ensure the efficiency of dust collection, a significant increase in fan power and performance is necessary;

- the high cost of the automatic control system for fan performance;

- the impossibility of visual control of the discharge of cast iron and slag. These shortcomings do not allow optimizing the operating mode of the aspiration system and minimizing the material costs of its implementation and energy costs during its operation.

The technical result of the invention is the optimization of the operating mode of the aspiration system, minimizing the material costs of its implementation and energy costs during its operation, increasing the degree of purification of aspiration gases.

The specified technical result is achieved due to the fact that a suction system of the foundry courtyard of the blast furnace is proposed, containing venting vents, local side suction from the cast iron and slag tap holes, umbrellas over the places of drain of cast iron and slag, a system for automatically controlling the suction system depending on the phase of the output of cast iron and slag , throttle valves for regulating the system depending on the phase of the production of pig iron and slag installed on the main and peripheral flues from local suction and umbrellas, filters exhaust emissions, a smoke exhaust system with an automatic control system, an industrial ventilation pipe with a flare discharge, while the ventilation gas vents of the aspiration system from dust and gas sources are located on metal structures outside the foundry building, and the local side suction from the cast iron and slag notches are combined with the supply of fresh air to the zone local side suction operation by a supply fan with a guide device working in the directions of a cast iron or slag tap hole, depending five from the release phase, and umbrellas at places pig iron and slag discharge opening equipped with viewing windows for monitoring the process of filling the bucket.

The proposed aspiration system of the foundry of a blast furnace is illustrated in figures 1-4.

FIG. 1 is a general diagram of a blast furnace foundry aspiration system.

FIG. 2 - front view, an umbrella located above the source of dust emission, in some places cast iron and slag discharge.

FIG. 3 is a side view, an umbrella located above the source of dust emission, in some places cast iron and slag discharge.

FIG. 4 - lateral local suction.

The blast furnace foundry’s aspiration system contains venting vents 1, local side suction from cast iron and slag tap 2, umbrellas above the cast iron and slag drains 3, throttle valves to regulate the system depending on the phase of the cast iron and slag 4, mounted on peripheral 5 (from local exhausts and umbrellas) gas ducts, suction exhaust filter 6, smoke exhaust system with automatic control system 7, industrial ventilation pipes with flare emission 8. Local side exhausts from cast iron and slag wood ca. 2 are aligned with the supply air in the working area of the local supply fan suction side to the guide device 9, running in the direction of cast iron or slag taphole according to the release phase. Umbrellas over cast iron and slag discharge places 3 are equipped with opening inspection windows 10 to control the process of filling the bucket.

Since the installation of an umbrella visor or umbrella above the tap hole in the foundry of the blast furnace is not possible due to the operation of the mechanisms that serve the tap hole, as a rule, lateral local suction of FIG. 4. Due to the fact that the air flow rate in such local exhausts largely depends on the closest possible location of the local exhaust to the source of dust emissions (X1), on the possibility of organizing local suction shelters to prevent unorganized air leakage, and the need to ensure the stability of the flow of harmful substances through towards the local suction, as well as the particle capture rate at a distance (Vx), in this project it is proposed to shift the dust particle capture point towards the local suction (X2), thereby venno reducing consumption aspiration system using directed toward local supply suction air stream.

Vx is the particle capture velocity at a distance of X1, X2, m / s;

X1 is the distance from the source of dusting to the intake device, m;

X2 - distance from the source of dusting to the intake device after the displacement of the capture point by the supply jet, m

The operation of the aspiration system of the foundry of the blast furnace.

At the time of the release of pig iron and slag through the side suction from the cast iron and slag tap 2 and the umbrellas above the drain points of cast iron and slag 3, depending on the phase of the exhaust, the system is regulated by throttle valves 4 of the dust emission enter the main 5 and peripheral flues 6 and then to the suction filter emissions (bag fabric filter) 7, a smoke exhaust system with an automatic control system 8 and into an industrial ventilation pipe with a torch 9.

It is proposed to use umbrellas located above the source of dust emission and equipped with opening inspection windows to control the process by local personnel to arrange local suction in the areas of cast iron and slag discharge. The dimensions of the windows should provide the ability to visually inspect the entire opening above the places where the iron and slag are drained. The opening mechanism is remote. The drive of the opening mechanism is mechanical or manual. As a mechanical one, an electric or pneumatic drive can be used.

Using the proposed system of aspiration of the foundry of a blast furnace will improve the operating mode of the aspiration system, minimize material costs for its implementation and energy costs during its operation, increase the degree of purification of aspiration gases released into the atmosphere.

Claims (2)

1. A blast furnace foundry aspiration system containing venting gas outlets, local side suction from cast iron and slag tap holes, umbrellas above the cast iron and slag discharge places, an automatic control system for the aspiration system depending on the phase of cast iron and slag discharge, throttle valves for its regulation depending on the phase of the production of pig iron and slag, installed on the main and peripheral flues from local exhausts and umbrellas, a suction filter, a smoke exhauster with an automatic control system and industrial vent pipe with a flare discharge, characterized in that the vent gas vents of the suction system from dust and gas sources are located on the metal structures outside the foundry building, and the local side suction from the cast iron and slag slots are combined with the supply of fresh air to the local side suction zone with the supply fan working in the areas of cast iron or slag tap holes, depending on the phase of the mentioned release. 2. The system according to p. 1, characterized in that the umbrellas above the places of discharge of cast iron and slag are equipped with opening inspection windows to control the process of filling the bucket.

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