WO2015038027A1

WO2015038027A1 - Melting unit

Info

Publication number: WO2015038027A1
Application number: PCT/RU2013/000800
Authority: WO
Inventors: Анатолий Анатольевич ГОЛУБЕВ; Юрий Александрович ГУДИМ; Ильяз Юнусович ЗИНУРОВ; Валерий Зиновьевич ФЕЛЬДМАН; Виктор Владиленович СЕРГЕЕВ
Original assignee: Общество С Ограниченной Ответственностью Промышленная Компания "Технология Металлов"
Priority date: 2013-09-16
Filing date: 2013-09-16
Publication date: 2015-03-19
Also published as: RU2590733C2; RU2014147199A

Abstract

The invention relates to the field of metallurgy, and specifically to the design features of a melting unit. The housing of a melting chamber is made to be demountable and is composed of a removable cooled upper portion and an uncooled lower portion. The removable cooled upper portion of the housing is in the form of a double-walled metal casing having a sealed cavity filled with a liquid metal heat transfer medium. A cooling system intermediary heat exchanger having a secondary liquid metal heat transfer medium is provided directly in the sealed cavity filled with the primary liquid metal heat carrier. A water-and-liquid-metal heat exchanger intended for cooling the secondary liquid metal heat transfer medium is provided on a support platform of the melting chamber. The lower uncooled portion of the melting chamber housing, which encompasses a metal bath, is lined with a refractory lining and is installed on a tiltable support platform having a tilting mechanism; the melting chamber is equipped with a lined refractory window for discharging metal using a spout having a slide-gate shutoff device.

Description

Smelter

The invention relates to metallurgy and to the field of processing solid industrial and household waste, can also be used in the energy sector for the combustion or gasification of coal with a high ash content on the surface of molten slag.

The walls of the metal casing of the melting chambers of the melting units have to be protected by refractory lining from the damaging effects of the high temperature of the working space. During operation of the melting chamber, the refractory lining is worn out as a result of exposure to high temperatures, chemical corrosion, and mechanical erosion of the refractory material. Therefore, the melting chamber is periodically stopped for cold repair of the lining, as a result, productivity decreases and the technical and economic performance of the melting unit deteriorates.

By ensuring the formation of a skull (conglomerate of sintered charge materials, lining particles, slag, dust) on the working (inner) surface of the metal body of the melting chamber, it is possible to significantly extend the time of continuous operation of the melting unit. It is possible to organize the formation of a skull on the working surface of the housing of the melting chamber by intensively cooling the outer surface of the wall of the housing.

In smelting units of ferrous and non-ferrous metallurgy, water is used to cool the walls of the casings of melting chambers [1, 2], despite the significant drawbacks of water as a heat carrier: the formation of a scale layer on the inner surface of the cooled element; the possibility of the formation of steam plugs when boiling water, leading to the destruction of the cooled case; explosion hazard when water enters from the destroyed water-cooled element into molten metal and slag.

In this regard, interest is shown in the creation of cooling systems for the bodies of the melting chambers of units that use not water as the heat carrier, but liquid metal coolants having significantly higher boiling points and better thermotechnical properties (thermal conductivity, heat capacity, etc.) [3].

In practice, melting chambers that use liquid metal coolants to cool the case are not yet used due to the complexity of the design and the difficulty of maintenance and repair [4-7].

As the closest analogue of the claimed technical solutions, the applicant selected the well-known "Method of cooling the body of the melting unit and the melting unit for its implementation" (patent RU 2383837) [8].

The known melting unit comprises a melting chamber with a metal body made in the form of a double-walled metal shell with an airtight cavity filled with a liquid metal coolant - sodium, a heat exchanger for cooling the liquid metal coolant with a gaseous coolant, a refractory lining of the molten metal bath, a charge, heating, and melting furnace charge for metal and slag, devices for removal and purification of furnace gases and utilization of their heat, heat exchanger for cooling the liquid metal coolant with a gaseous coolant is located directly on the casing of the melting chamber, its outer shell is located at a distance of 50-300 mm in diameter from the outer wall of the melting chamber and is made in the form of a sealed metal cylinder or part thereof with pipes for supplying cold and selecting a heated gaseous coolant, covering the melting chamber, the outer wall of which serves as the inner shell of the heat exchanger, while in the cavity between the outer wall melted Curved copper strips are fixed at a distance of 300 mm from each other on the outer chamber and on the outer shell of the heat exchanger on the outer wall of the melting chamber.

The body of the melting chamber has an opening with a cooled pipe for the selection of gaseous products of melting from the melting chamber and using them to heat the charge materials before loading into the melting chamber in the heater, as well as for loading heated charge materials into the melting chamber.

The body of the melting chamber has an opening with a docking cooled device configured to direct the gaseous products of melting into an energy recovery boiler for utilizing the physical and chemical heat of the gaseous products of melting and generating steam for generating electricity.

Known melting unit has the following disadvantages:

- one-piece metal casing of the melting chamber with relatively small holes for loading the charge and sampling gaseous fusion products (with a diameter of about 1 m) makes it very difficult to supply refractories and to lay the refractory lining of the metal bath in preparation for the operation of the melting unit and, if necessary, to repair it;

cooling the lower part of the body of the melting chamber, covering the refractory lining of the metal bath, leads to the formation of a metal coating on the lining and a decrease in the volume of the metal bath;

- cooling of the primary liquid metal coolant - sodium with a secondary gaseous coolant in a heat exchanger located directly on the body of the melting chamber, requires the organization of the movement of the gaseous coolant in the heat exchanger at a very high speed and leads to a very large flow of the gaseous coolant and the need for a powerful blower in the workshop;

- when the grooves for the release of metal are located in the lower part of the slope of the refractory lining of the bath, it is very difficult and difficult to open it due to the formation of a durable refractory conglomerate from refractory material and metal residues in it, as evidenced by many years of experience in operating melting units in metallurgy (blast furnaces, open-hearth furnaces, etc.); - it is difficult to organize the discharge of finished metal from the melting chamber in several portions;

- it is difficult to quickly completely drain the metal from the melting chamber in the event of an emergency.

The task of the invention is to eliminate the disadvantages of the closest analogue and increase the efficiency and reliability of the melting unit.

The technical results of the invention are:

- increase the productivity of the smelting unit;

- reduction of the total consumption of heat and electric energy for the production of marketable products;

- facilitating maintenance of the unit by personnel.

Technical results are achieved in that in a melting unit containing a melting chamber with fuel-oxygen burners, a charge material heater with heat from the gases leaving the melting chamber, a cooling system of the melting chamber body, a metering and loading system of charge materials, a device for separately draining metal and slag, a device for heat recovery of gases leaving the charge material heater, according to the invention, the housing of the melting chamber is made detachable, consisting of removable cooling of the upper and uncooled lower parts, the case connector line is at a height of 200-400 mm from the calculated maximum level of liquid metal in the metal bath, the removable cooled upper part of the body is made in the form of a double-walled metal shell with a sealed cavity filled with a liquid metal coolant, an intermediate heat exchanger of the cooling system with the secondary liquid metal coolant is placed directly in the sealed cavity filled with the primary liquid metal coolant, it is one-liquid metal heat exchanger to cool the secondary liquid metal the coolant is placed on the supporting platform of the melting chamber, the lower uncooled part of the body of the melting chamber, covering the metal bath, is laid out with a refractory lining and installed on an inclined supporting platform equipped with a tilt mechanism, for the discharge of metal, the melting chamber is equipped with a lined refractory bay window equipped with a notch with a sliding shut-off device, the walls of the refractory lining of the metal bath are raised into the space of the removable water-cooled upper part of the body 200-500 mm above the line Connectors housing.

The angle of inclination of the support platform with a melting chamber mounted on it relative to the transverse horizontal axis is 4-7 ° in opposite directions

The primary and secondary liquid metal coolant is sodium.

The primary and secondary liquid metal coolant is a lead-bismuth alloy.

In the charge material heater, the heat leaving

a melting chamber of gases installed fuel-oxygen burner.

In the charge material heater, the heat leaving

The gas melting chamber has two fuel-oxygen burners.

The melting unit is equipped with a shaft heater of charge materials with heat from the gases leaving the melting chamber,

located on the site of the melting chamber.

The melting unit can be equipped with an inclined mounted rotating cylindrical heater of charge materials with heat of the gases leaving the melting chamber.

The detachable casing of the melting chamber allows, having removed the upper part of the casing, without special difficulties to feed into the lower part of the casing melting chamber refractories and laying the lining of the metal bath in preparation for the operation of the melting unit or, if necessary, repair the lining of the bath, which reduces the preparation time of the unit or repair time and increases its productivity.

The location of the connector line of the body of the melting chamber at a height of 200-400 mm from the calculated maximum level of molten metal in the metal bath, in addition to the main effect, eliminates the possibility of liquid metal leaving the melting chamber through the housing connector and eliminates emergency unit downtime.

The location of the connector line of the body of the melting chamber below 200 mm from the calculated maximum level of molten metal in the metal bath increases the likelihood of possible withdrawal of molten metal from the melting chamber in the event of an unexpected increase in metal volume.

The location of the connector line of the body of the melting chamber above 400 mm from the calculated maximum level of molten metal in the metal bath reduces the height of the removable upper cooled part of the body of the melting chamber, respectively, reduces the area of the cooled surface of the body protected by the skull and increases the size of the lining of the bath and the consumption of refractory materials.

The cooling of the primary liquid metal coolant located in the sealed cavity of the double-walled metal shell of the housing by the secondary liquid metal coolant passing through the intermediate heat exchanger located directly in the sealed cavity of the double-walled metal shell of the housing makes it possible to sharply reduce the size of the intermediate heat exchanger and eliminate the need for a large flow rate of the secondary gaseous heat carrier, to eliminate the need installation of a powerful blower for under Get a gaseous coolant and reduce the total energy consumption for production.

Placement of a water-liquid metal heat exchanger for cooling a secondary intermediate liquid metal coolant directly on the supporting platform of the melting chamber allows you to reduce the size of the cooling system of the housing of the melting chamber, to increase the reliability of the melting unit, eliminate downtime and increase the performance of the unit.

The uncooled lower part of the body of the melting chamber having a refractory lining, covering a metal bath, reduces the intensity of heat removal from the metal bath, the metal in it does not cool, the possibility of forming a metal coating on the lining and reducing the volume of the metal bath is excluded, which increases the unit's productivity.

A bay window of the melting chamber lined with refractories, equipped with a tap-hole shutter, significantly facilitates and accelerates the opening and closing of the tap hole, provides timely drainage of metal from the melting chamber, which increases the productivity of the unit and facilitates its maintenance.

The installation of a melting chamber on an inclined support platform equipped with a tilt mechanism allows the metal and slag to be drained in portions and the fast and high-quality service of the metal bay window of the bay window (closing the slide gate device and filling the bay with refractory powder), which increases productivity and facilitates maintenance of the unit by personnel.

The angle of inclination of the support platform with the melting chamber mounted on it relative to the transverse horizontal axis, ranging from 4 to 7 ° in opposite directions, provides the ability to facilitate and quick service of the bay window with a minimum increase in the load on the design of the melting unit. An inclination angle of the support pad of 4 ° is convenient for large melting units, an inclination angle of 7 ° is convenient for small units.

Raising the walls of the refractory lining of the metal bath of the melting chamber in the upper cooled part of the body of the melting chamber 200-500 mm above the connector line of the body of the melting chamber provides a guaranteed elimination of the possibility of damage the working surface of the wall of the body during boiling and lifting of liquid metal during operation of the melting unit, which eliminates downtime and increases the performance of the unit.

The continuation of the laying of the refractory lining of the metal bath in the upper cooled part of the body of the melting chamber by 200 mm is convenient for large melting units having a large surface area of the bath.

The continuation of the laying of the refractory lining of the metal bath in the upper cooled part of the body of the melting chamber by 500 mm is convenient for small melting units having a small surface area of the bath.

The use of sodium as the primary and secondary liquid metal coolants, which has the best heat engineering properties among the known liquid metal coolants, allows you to intensively remove heat from the inner working wall of the upper part of the melting chamber body, ensures the formation and constant presence of a skull on it, reduces and eliminates the time required to repair the lining and increases unit productivity.

The use of a lead-bismuth alloy as a primary and secondary liquid metal coolant also allows heat to be removed from the inner working wall of the upper part of the melting chamber body with sufficient intensity, ensures the formation and constant presence of a skull on it, reduces and eliminates the time required for repairing the lining, and increases unit productivity .

The use of a lead-bismuth alloy is more advantageous in cases where in a workshop using a melting unit it is not possible to provide the highly qualified staff and a high production culture necessary for working with sodium as a liquid metal coolant. The installation of one or two fuel-oxygen burners in the charge material heater by the heat of the gases leaving the melting chamber allows to increase the heating temperature of the charge materials and thereby increase the productivity of the melting unit without changing the dimensions of the melting chamber.

A shaft heater of charge materials with heat of gases leaving the melting chamber located on the site of the melting chamber allows to efficiently heat bulk charge materials, increase the productivity of the melting unit and improve its technical and economic performance.

The inclined mounted cylindrical rotary heater of charge materials by the heat of the gases leaving the melting chamber allows efficiently heating small bulk charge materials, increasing the productivity of the melting unit and improving its technical and economic performance.

The design and operation of the melting unit are illustrated in figures 1, 2 and Z.

The melting unit comprises a melting chamber 1 with a detachable metal casing. The upper removable cooled part 2 of the body of the melting chamber 1 is made in the form of a double-walled metal shell with an airtight cavity 3 filled with a primary liquid metal coolant, an intermediate heat exchanger with a secondary liquid metal coolant is located directly in a sealed cavity 3 filled with a primary liquid metal coolant, a water-liquid metal cooling 4 secondary intermediate coolant is located next to the melting chamber 1 directly on the op The site 5 of the melting chamber 1.

The lower part of the housing 6 of the melting chamber 1, covering the metal bath 7, is made uncooled, has a refractory lining 8. The melting chamber 1 is mounted on an inclined support platform 5, equipped with a tilt mechanism 9, allowing to tilt a support platform 5 with a melting chamber 1 mounted on it and a water-liquid metal heat exchanger 4 with respect to the transverse horizontal axis located below the maximum level of the metal in the metal bath 7.

The melting chamber 1 has a bay window 10 lined with refractory bricks, equipped with a drain hole 11 with a sliding shut-off device 12. The refractory lining 8 of the metal bath 7 is raised above the connector line of the housing of the melting chamber 1 to the upper cooled part 2 of the body of the melting chamber 1.

In the upper cooled part 2 of the casing of the melting chamber 1, a hole 13 is made for loading charge materials and a hole 14 for removing exhaust gases from the chamber 1 to the gas heat recovery system equipped with special pipes 15, 16 for connecting the melting chamber to the charge loading systems (not shown conventionally ) and heat recovery of exhaust gases (not conventionally shown).

In the upper part 2 of the casing of the melting chamber 1, in special nozzles are also placed oxygen-fuel burners 17, injectors for injecting powdered materials into the melt 18 and a device 19 for sampling metal, slag and measuring the temperature of the melt. To drain the slag, the melting chamber 1 has a slag notch 20 with a locking mechanism 21 and a drain trough 22.

The melting unit is prepared for operation and put into operation as follows.

When the upper cooled part 2 of the casing of the melting chamber 1 is removed, the refractory lining 8 of the metal bath 7 and the bay window 10 are laid out in the lower uncooled part 6 of the casing of the melting chamber 1. Then, the upper cooled part 2 of the casing of the melting chamber 1 is installed on the lower part 6 of the casing, and the laying of the refractory lining is continued. 8 metal bath 7 in the upper part 2 of the housing of the melting chamber 1 to the required height, connect the melting chamber 1 with the systems for feeding the charge, heat recovery of exhaust gases and cooling in the upper part 2 of the housing. Next fill the system cooling the housing with a liquid metal coolant and start heating the melting chamber 1 by turning on the fuel and oxygen burners 17 at half the maximum power when the cooling system of the upper part 2 of the housing of the melting chamber 1 is operating.

After heating the lining 8 of the metal bath 7 to a temperature of 1000 ° C, the loading of the metal charge into the melting chamber 1 begins through the heating system of the charge materials and the feed opening 13. Fuel-oxygen burners 17 are turned on at full power. Filling the metal bath 7 with molten metal, a standard charge containing metal, ore, slag components and, if necessary, a carbon reducing agent is loaded into the melting chamber through opening 13.

The melting unit switches to continuous operation. As a result of intensive cooling by liquid metal coolant of the working surface of the upper part 2 of the housing of the melting chamber 1, a layer of a skull is formed in this slag zone and in free space above the slag on this cooled surface.

Accumulating excess metal is periodically drained from the melting chamber 1 into a steel pouring ladle placed under the bay window 10. To do this, open the drain hole 1 1 by turning the slide gate device 12.

To close the drain hole 11 after the discharge of metal, tilt the support platform 5 to the side opposite to the bay window 10, freeing the drain hole 1 1 from the liquid metal. Then close the slide gate device 12 and fill the drain hole 1 1 with refractory powder.

Excessive amount of slag is poured periodically or continuously from the melting chamber 1 through the slag notch 20, by opening the locking mechanism 21, through the drain trough 22 into the slag bowl.

Gases generated during operation of the melting unit are discharged from the melting chamber 1 to the heating systems of charge materials and heat recovery of gases through the hole 14 through the pipe 16. Further, the melting unit operates continuously for a long time until it becomes necessary to repair the lining of the free space and the slag zone. The elimination of the need for cooling the lower part of the housing 6 of the melting chamber 1 and the presence of a bay window 10 with a drain hole 1 1 simplifies and facilitates the organization of the discharge of metal from the melting chamber 1, and does not lead to the formation of a metal bath 7 on the hearth.

Thus, the present invention makes it possible to carry out a long continuous process of melting and processing various charge materials without stopping the melting unit for repairing the lining, and to reduce operating costs during operation of the melting unit.

Information sources

1. Gudim Yu.A. Steel production in arc furnaces. Constructions, technology, materials. / U.A. Goodim, I.Yu. Zinurov, A.D. Kiselev - Novosibirsk. Publishing house of NSTU, 2012 .-- 547 p.

2. Utkin N.I. Non-ferrous metal production. - M. Intermet Engineering. 2004 .-- 442 p.

3. Liquid metal coolants / Borishansky V. M., Kutateladze S. S, Novikov I.I. et al. - M: Atomizdat, 1976 .-- 328 p.

4. British Patent J ”1566980, cl. F27D 1/12, 1980.

5. US patent N ° 4913734, CL. F27B 1 1/08, 1990.

6. US Patent JYO 3735010, CL F27D 1/12, 1973.

7. Patent RU 2067273 "Method for cooling a melting furnace and a melting furnace for its implementation." Authors: Belinsky BC, Borisov V.V., Oleichik V.I., Poplavsky V.M., Denisov V.V., Reshetov O.I., Reshetin A.S., Oleichik I.V., Kravchenko I. N. Patentee: Joint Stock Company "Technoliga".

8. Patent RU 2383837 "Method for cooling the body of the melting unit and the melting unit for its implementation." Authors: Golubev A.A., Gudim Yu.A., Tregubov I.O., Sergeev VV, Nadinsky Yu.N. Patent holder: Limited liability company Industrial company "Technology of metals".

Claims

F O R M U L A

1. A melting unit comprising a melting chamber with fuel-oxygen burners, a heater for charge materials with heat from the gases leaving the melting chamber, a cooling system for the body of the melting chamber, a metering and loading system for charge materials, a device for separately draining metal and slag, a device for recovering heat from the exhaust gases from a charge material heater, characterized in that the body of the melting chamber is made detachable, consisting of a removable cooled upper and uncooled lower parts, the case connector line is located at a height of 200-400 mm from the calculated maximum level of liquid metal in the metal bath, the removable cooled upper part of the case is made in the form of a double-walled metal shell with a sealed cavity filled with a liquid metal coolant, an intermediate heat exchanger of a cooling system with a secondary liquid metal coolant is located directly in sealed cavity filled with primary liquid metal coolant, water-liquid metal heat exchanger for cooling The secondary liquid metal coolant is placed on the supporting platform of the melting chamber, the lower uncooled part of the housing of the melting chamber, covering the metal bath, is laid out with a refractory lining and installed on a tilting supporting platform equipped with a tilt mechanism. To drain the metal, the melting chamber is equipped with a lined refractory bay window equipped with a bay window locking device, walls of the refractory lining metal bathtubs are raised into the space of the removable water-cooled upper part of the housing 200-500 mm above the line of the housing connector.

2. The melting unit according to claim 1, characterized in that the angle of inclination of the supporting platform with the melting chamber mounted on it relative to the transverse horizontal axis is 4-7 ° in opposite directions

3. The melting unit according to claim 1, characterized in that the primary and secondary liquid metal coolant is sodium.

4. The melting unit according to claim 1, characterized in that the primary and secondary liquid metal coolant is a lead-bismuth alloy.

5. The melting unit according to claim 1, characterized in that a fuel-oxygen burner is installed in the charge material heater by the heat of the gases leaving the melting chamber.

6. The melting unit according to claim 1, characterized in that two fuel-oxygen burners are installed in the charge material heater by the heat of the gases leaving the melting chamber.

7. The melting unit according to claim 1, characterized in that it is equipped with a shaft heater of charge materials with heat of the gases leaving the melting chamber located on the site of the melting chamber.

8. The melting unit according to claim 7, characterized in that it is equipped with an inclined mounted rotary cylindrical heater of charge materials with the heat of the gases leaving the melting chamber.