RU2459167C2 - Destruction method of slag scaffolds in shaft furnaces - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: in order to destruct slag scaffolds in shaft furnaces, acoustic filed created with supply of acoustic vibrations flow to concurrent flow of air blowing supplied through tuyeres to the working space of lower part of the furnace, and distribution of acoustic field immediately in the layer is provided. At that, acoustic field is created with acoustic power of 0.1-0.6 W/m³ and vibration frequency set depending on thickness of formed scaffolds in the range of 100-1000 Hz.

EFFECT: removal of scaffolds without increasing volumes of hazardous emission to atmosphere using simple economic method, which increases the furnace capacity.

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Description

The method relates to metallurgy, and in particular to the production of liquid melt in smelting units of a mine type (iron foundry and mineral wool cupolas, shaft furnaces of non-ferrous metallurgy, etc.)

The aim of the invention is to reduce the cost of servicing shaft furnaces by destroying the slag deposits formed by heating the starting components in the upper part of the shaft of the furnace.

During the operation of melting furnaces due to the sequential melting of the charge components by the upward gas flow and the cooling effect of the walls, a slag skull (crust) is formed, the presence of which reduces the internal section of the furnace and reduces the unit's productivity.

A known method of removing slag deposits from side surfaces using simple mechanical devices (V. I. Smirnov. Mine smelting in the metallurgy of non-ferrous metals. Sverdlovsk: GNTI, 1955, p. 424-427). It is notable for ease of implementation. However, a significant amount of manual labor, difficulties arising from the removal of accretions in hard-to-reach places, reduce the efficiency of cleaning the inner surface of the working space of smelting furnaces.

Existing methods for removing crusts in high-temperature slag massifs using explosives (Explosive removal of high-temperature crusts in metallurgical units. Bershak VI, Dvoskin EM, Schurchkov VP, Bochkarev LM, Tyumentsev V.G. ., Gagarinsky V.P., Aranovich V.L. - Non-ferrous metallurgy, 1984, No. 3, p. 73-74) are characterized by complexity of implementation (Special permission for use is required, special means for delivery, storage, etc.). Moreover, the design of the furnace experiences an additional mechanical effect from the blast wave, which reduces its life.

A group of methods that can reduce the process of nastyleobrazovaniya in the working space of metallurgical units, involves the use of additional heat sources in the form of chemical heat of the fuel burned in the immediate vicinity of the slag formations (Method for removing deposits in metallurgical furnaces. Intykbaev AM, Bagaev IS, Gasukha N .A. Ust-Kamenogorsk lead-zinc combin named after V.I. Lenin, A.S. USSR 1084575, application no. 1252.895 / 22-02 on 12/14/82, published in BI 1984, No. 13, MKI F27D 1/16) or the use of special reagents in the form of high-temperature asplavov (Method removal mederafinirovochnyh accretion in rotary furnaces and ladles transmission technology: Russian Pat 2118387, IPC ⁶ C22B 15/14 / Eroshevich SY, Nicholas A., V. Lazarev, Kucherenko EA, Makarov T.A., Kruchinin A.A., Makarov D.F., Babakov V.I., Starostin S.N .: AO Norilsk Mining and Metallurgical Combine - No. 97115601/02, Claim 22.09.97. Published in BI 08/27/98, No. 24).

These methods require additional fuel consumption, time for the fusion of nastily, which reduces the performance of the main unit, and also increase the amount of harmful emissions into the atmosphere. Their use significantly increases production costs, reducing its effectiveness.

The closest in technical essence of the claimed invention is the removal of crusts in high-temperature slag masses using explosives (explosive removal of high-temperature crusts in metallurgical units. Bershak VI, Dvoskin EM, Schurchkov VP, Bochkarev L.M. ., Tyumentsev V.G., Gagarinsky V.P., Aranovich V.L. - Non-ferrous metallurgy, 1984, No. 3, pp. 73-74), which was adopted as a prototype. The method is characterized by complexity of implementation: special permission is required to use special equipment for delivery, storage, etc. Moreover, the design of the furnace experiences an additional mechanical effect from the blast wave, which reduces its life.

An analysis of the analogues and prototype described above revealed that none of them achieves the desired result - the creation of a simpler, economical way to remove accretions in shaft furnaces without increasing the amount of harmful emissions into the atmosphere.

The inventors of the present application, a method for the destruction of slag deposits in shaft furnaces with the achievement of the specified technical result is created.

The essence of the invention lies in the fact that the nastole is exposed to an acoustic field created by applying a stream of acoustic vibrations to a satellite stream of air blast supplied through tuyeres to the working space of the lower part of the furnace, ensuring the distribution of the acoustic field directly in the layer, and the acoustic field creates sound power 0 , 1-0.6 W / m ³ and the oscillation frequency, set depending on the thickness of the formed accretions in the range of 100-1000 Hz.

Formed acoustic field directly in the working space of shaft furnaces creates conditions for periodic mechanical impact on sintered particles of a layer with a certain amplitude, which leads to the destruction of their agglomerates. The acoustic field is created using acoustic emitters of the gas-jet principle of action, installed in the lower part of the furnace in accordance with the distribution of accretions. For this purpose, a stream of acoustic vibrations of a given sound power is supplied on a special nozzle mounted on an air lance into a satellite stream of air blast. Leaving the tuyeres, the acoustic field is distributed directly in the layer, providing an effect on the formed nastily. Moreover, most of its energy is used in the working space of the furnace without loss in the environment.

Table 1 shows the distribution of the volume of sintered particles of the mixture depending on the size of the working space of the melting unit.

Table 1 The average volume of nastily depending on the volume of the furnace The amount of working space, m ³ 2.5 4,5 12.5 36 54 Volume of crusts, m ³ 0.56 0.75 1.25 3.0 4.2

From the above data it can be seen that the volume of accretions largely depends on the volume of the working space of the furnace. Therefore, the power of the generated acoustic field should be selected depending on the performance and size of the unit. The larger the volume of its working space, the higher should be the sound power of an acoustic field capable of destroying slag formations. In addition, the greater the thickness of the layers, the lower the oscillation frequency should be to ensure resonant conditions between external periodic oscillations and destructible cakes.

The destruction efficiency of slag formations is achieved at a vibration frequency of 100 ... 1000 Hz. At the same time, the operation of acoustic emitters in the frequency range below 100 Hz is characterized by low efficiency and requires a significant consumption of compressor air. The increased consumption of additional air supplied to the shaft of the furnace, worsens the conditions of combustion of coke in the layer, heat transfer and the operation of the exhaust pipe. At an oscillation frequency above 1000 Hz, resonance with nastily is not achieved and the process of their destruction does not occur.

The power of the sound field generated in the working space of the shaft furnace should be in the range of 0.1 ... 0.6 W / m ³ . Exceeding the maximum level of used sound power reduces the efficiency of destruction of accretions due to the distribution of the input resonant power over the entire layer. A decrease in the sound power level below 0.1 W / m ³ does not provide the necessary effort for the destruction of accretions on the inner surface of the working space of shaft furnaces (Table 2), causing an increase in the cost of their additional removal.

The invention used creates conditions for the continuous destruction of the resulting slag cakes in the upper part of the shaft furnace, which increases the productivity of the unit by 10 ... 15%.

table 2 Examples of the proposed method No. of examples Sound power of acoustic radiation, W / m ³ Radiation frequency, Hz The number of additional explosions to remove accretions, pcs / month one 0.1 fifty 12 2 0.1 1000 10 3 0.3 one hundred 9 four 0.3 1000 5 5 0.6 one hundred 5 6 0.6 1000 2 7 0.6 1100 10 8 0.8 1100 fourteen 9 prototype - - 22

Claims (1)

A method of destroying slag deposits in mine furnaces, characterized in that the impacts are affected by an acoustic field created by feeding a stream of acoustic vibrations into a satellite stream of air blast supplied through tuyeres to the working space of the lower part of the furnace, ensuring the distribution of the acoustic field directly in the layer, and the acoustic the field is created by a sound power of 0.1-0.6 W / m ³ and an oscillation frequency set depending on the thickness of the formed accretions in the range of 100-1000 Hz.