RU2529348C1 - Reverberatory furnace for remelting of aluminium scrap - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: furnace consists of a case made with refractory external side, front and back end walls, a storage bath and an inclined platform restricted with a sole and walls, two drain tapholes, a rotating pan, a gas duct and a welded frame whereon everything is arranged. The furnace case is fitted by a welded steel box equipped with heat insulation between the box and each wall consisting of double heat insulation mullite fibreglass layer and of sheet asbestos cardboard. The storage bath and the inclined platform are made from mullite corundum blocks of increased density which are laid on the heat insulation mullite fibreglass layer and light brick. The furnace case is filled by concrete with the filler from crushed light fire brick, the crown above the inclined platform and the bath has heat-insulation plaster above which double layer of refractory heat-insulation mats is laid. One side wall of the furnace is provided with two injection ten-mixer medium-pressure burners directed at an angle to the inclined platform while another side wall is furnished with one injection ten-mixer burner directed at an angle to the inclined platform and one 19-mixer burner directed to the furnace bottom, a reheat chamber lined by refractory bricks to house a four-mixer gas injection burner, an air blower, two tapholes in the side walls to let out the molten metal made in the quick-change taphole bricks.

EFFECT: higher furnace efficiency, reduced heat and burn-off losses and possibility of ecologically clean remelting of aluminium scrap.

7 cl, 12 dwg

Description

The invention relates to ferrous metallurgy, and in particular to smelting units for remelting secondary aluminum scrap and waste aluminum alloys into ingots and ingots. The furnace can be used for refining, producing alloys, averaging the chemical composition of scrap.

A known analogue is a reflective furnace for remelting metal (RF patent information No. 2155304), comprising a housing formed by masonry of external walls, as in the claimed furnace, a storage bath and an inclined platform limited by a hearth and walls, a vault, a drain outlet and a flue.

The disadvantages of this furnace are:

1. The complexity of the design due to the presence of two arches (small above the loading table and large above the bathroom).

2. The lack of external thermal insulation of the furnace, reducing heat loss to the external environment.

3. The furnace does not have a dust and gas cleaning system and during operation will pollute the environment with harmful emissions.

4. From the description of the furnace it follows that it is equipped with only one nozzle. This is clearly not enough to ensure a high rate of penetration of the charge and maintaining a forced melting mode. Due to the above disadvantages, the furnace cannot provide a solution to the technical problem.

A known analogue is a reflective furnace for remelting metal (information source RF patent No. 2047663), comprising a housing formed by brickwork of external walls, as in the claimed furnace, a storage bath and an inclined platform limited by a hearth and walls, a vault, a drain and a flue.

The furnace is designed for remelting secondary aluminum and has the following disadvantages:

1. The high cost and complexity of the accumulating heat pillows (lightweight refractory bricks, blooms). The large depth of the liquid metal in the bath makes the mixing process difficult, as a result of which the liquid metal will not be homogeneous.

2. The lack of external thermal insulation of the furnace, reducing heat loss to the external environment.

3. The furnace does not have a dust and gas cleaning system and during operation will pollute the environment with harmful emissions.

4. The furnace uses a stationary chute to drain molten metal.

Due to the above disadvantages, it is impossible to obtain a technical result.

A known analogue is a reflective furnace for smelting metal (information source RF patent No. 2361162), which is the closest (prototype), containing a housing formed by refractory outer side, front and rear end walls, as in the claimed furnace, a storage bath and an inclined platform, limited a hearth and walls, a vault, a drainage notch and a gas duct, the housing being placed on a welded frame. The oven, taken as a prototype, has the following disadvantages:

1. The furnace does not have a afterburner and a dust and gas treatment unit.

2. The furnace has high productivity, but its productivity can still be increased.

3. The furnace has satisfactory tightness. Due to the special design of the shutter of the working and slag windows, it is possible to create a sealed furnace, which allows to reduce emissions of harmful gases into the atmosphere, to reduce the loss of metal and heat into the environment.

4. The furnace has a step from the inclined platform to the hearth, which does not allow using the loader with a scraper to clean the hearth and inclined platform (ie, to mechanize the cleaning process of the hearth and inclined platform).

5. The hearth blocks MKRS-50 are used in the furnace, which have a sufficiently long service life, however, by using other hearth blocks for the hearth and inclined platform, it is possible to increase the life of the furnace.

The objective of the invention is the creation of a high-performance gas bath of a reflective type furnace for remelting aluminum scrap, having a afterburner, a dust-and-gas cleaning unit, which is sealed, which allows to reduce emissions of harmful gases into the atmosphere, reduce metal and heat losses into the environment, and also increase its lifetime.

EFFECT: developed furnace is hermetic, having a long service life, high-performance, allowing: to use scrap unsorted from foreign inclusions, to reduce heat loss to the environment due to special thermal insulation, to conduct the process of remelting on natural and artificial draft with a afterburner and a dust and gas treatment unit, making it environmentally friendly.

The specified technical result is achieved due to the fact that in a reflective furnace for remelting aluminum scrap, containing a housing formed by refractory outer side, front and rear end walls, a storage bath and an inclined platform bounded by a hearth and walls, a roof, a drain drain and a flue, according to the present invention introduced a welded frame, filled with concrete with a filler: crumb lightweight fireclay bricks, storage tank and inclined platform made of mullite-corundum increased-pl tnyh MKFPP blocks 88 stacked on the insulating mullite MLF-260 brand glass fiber layer and lightweight brick SHL-0.9. Concrete with a filler: crumb of lightweight fireclay bricks, heat-insulating mullite grade MLF-260 fiberglass layer and lightweight bricks SHL-0.9 under the hearth and under the inclined platform can reduce heat loss, maintain the temperature of the metal in the bathtub and inclined platform. The service life of the furnace is increased due to the use of mullite-corundum high-dense blocks MKFPP-88, which have high refractoriness and resistance (service life according to practical data is 8-8.5 years).

In addition, the reflective furnace for remelting aluminum scrap has two injection ten-mixing burners of medium pressure in one side wall, angled at an inclined platform, in the other side wall one injection ten mixing machines with a smooth internal surface of the mixers, angled at an inclined platform, and another 19-mixing, aimed at the bottom of the furnace. The 19-mixing burner has seven faucets with nozzles in the center that allow you to get a 2.8-meter long torch, the rest of the mixers are used without nozzles and have a 1.5-meter torch, two ten-mixing burners have five mixers in the top row, made with ribs on their ends inside the central channel, giving a 2.4-meter long torch when burning a gas-air mixture, mixers located in the bottom row make it possible to obtain a 1.3-meter torch. This arrangement of the burners allows to achieve a high melting rate, reduce fumes (according to practical data), as well as to load an uncontaminated charge through a slag window and to quickly melt it due to the heat generated during the burning of a torch of a 19-mixing burner. The thermal power of the burners is 7540 kW, which makes the furnace highly productive, allowing for forced melting.

In this case, the reflective furnace for remelting aluminum scrap has two slots in the end (rear) wall for the release of molten metal, made in quick change bricks, each bricks is placed in the welded box of the bricks, which has a flange with four holes for fastening to the box of the furnace In addition, the furnace has two lined rotary bowls with lined rotary troughs welded to them, which can be rotated during the pouring of molten metal and at the same time provide to pour the cast metal deposited in the furnace into the filling equipment.

Moreover, a steel box is welded to the furnace frame, which has heat insulation between it and each wall, consisting of a double heat-insulating mullite grade MLF-260 fiberglass layer and sheet asphalt board. This design solution significantly reduces heat loss to the environment.

It is important to note that the arch of the furnace has a refractory heat-insulating coating and a heat-insulating mullite grade MLF-260 with a glass fiber layer 30 mm thick is laid on top of it. This further reduces heat loss from the furnace.

Further, the furnace has a hydraulic drive for raising and lowering the furnace working damper, consisting of two power cylinders, an oil pump, brackets rotating on axes welded to the furnace body, as well as cast iron damper with double heat-insulating mullite grade MLF-260 fiberglass lined with lightweight one and a half refractory bricks, the lining protruding beyond the damper plane by 30 mm and, when closed, a reliable “L-shaped lock” is formed, which helps to reduce fumes and heat losses from the furnace. The slag window of the furnace has a frame lined with a lightweight one and a half brick protruding 30 mm beyond the frame, and the frame has two sliders on each side, welded to it, moving along the copiers, while closing the slag window forms a reliable “L-shaped lock” », Which helps to reduce fumes and heat loss from the furnace. The drive for raising and lowering the shutter slag window of the furnace consists of: an electric motor, a coupling, a worm gear, a drum, a counterweight, cables, pulleys and a shutter with a heat-insulating layer.

It should be noted that the reflective furnace for remelting aluminum scrap is equipped with a lined refractory brick a afterburner, in which a gas four-mixing injection burner with nozzles is installed, the afterburner has a door in the side wall lined with lightweight fireclay bricks, which opens and closes manually, and a blower is placed on top.

At the same time, the flue coming out of the afterburner has a slide gate that rises and lowers manually with the help of a counterweight.

Finally, the reflective furnace is equipped with a dust and gas cleaning installation to achieve an environmentally friendly process, and the dust and gas cleaning installation has two identical units combined into one whole dust and gas cleaning design, the units have two rotary grilles and eighteen cartridge filters, in addition, the installation has a service platform for preventive maintenance on blowers and blocks serving a platform for loading adsorbent into dust and gas cleaning blocks and a common staircase.

Introduction to the furnace design of the above devices, materials, etc. provides a solution to the problem.

The presence of an inclined platform that smoothly passes into the hearth allows the furnace to be remelted of scrap unsorted from foreign inclusions, since alterations (cast iron and steel rings, liners, bushings, studs, pushers, valves, etc.) do not fall into the molten metal, moreover, it is possible to clean using a loader equipped with a scraper.

Figure 1 is a plan view of the furnace.

Figure 2 is a longitudinal section aa of the furnace.

Figure 3 is a view B of the furnace.

Figure 4 - view In the furnace from the side of the working window.

Figure 5 - 19-mixing burner.

6 is a section GG G-mixing burner.

In Fig.7 - two-row ten-mixing burner with nozzles.

On Fig - two-row ten-mixing burner without nozzles.

In Fig.9 - two-row four-mixing burner with nozzles.

Figure 10 - installation of gas cleaning (front view).

11 is a view E of the installation of dust and gas cleaning.

12 is a plan view of a furnace with casting equipment and a dust and gas cleaning installation.

The proposed furnace contains: mounted on a frame 1 filled with concrete with a filler - a crumb of lightweight fireclay bricks, a casing formed by brickwork of the outer side, front 2 and rear 3 end walls.

Under 4 furnaces and an inclined platform 5 have a smooth transition and are laid out of mullite-corundum high-density blocks MKFPP-88 6, laid on a heat-insulating mullite grade MLF-260 fiberglass layer 7 and lightweight brick ШЛ-0,9 8 (Fig. 2). The heat-insulating mullite brand MLF-260 fiberglass layer 7 with a thickness of 30 mm is obtained by rolling on a frame 1 rolls of heat-insulating mullite fiberglass material of the brand MLV-260 with a width of 1400 mm, 15000 mm long, 30 mm thick. Frame 1 is welded from a wide-shelf I-beam No. 40 SHZ, poured with concrete 9 with a filler - a crumb of lightweight fireclay bricks - and reinforced with a corner of 90 × 90 10. Concrete 9, poured into a frame 1 with a filler-crumb of lightweight chamotte bricks, heat-insulating mullite grade MLF-260 fiberglass layer 7 and lightweight brick 8 under the hearth 4 and under the inclined platform 5 can reduce heat loss, maintain the temperature of the metal in the bath and the inclined platform. The service life of the furnace is increased due to the use of mullite-corundum high-dense blocks MKFPP-88, which have high refractoriness and resistance (service life according to practical data is 8-8.5 years). The use of mullite-corundum high-density blocks MKFPP-88 (large: length 1000 mm, width 400 mm, thickness 300 mm, small: length 500 mm, width 400 mm, thickness 300 mm) instead of conventional piece products, the number of joints can be reduced, which reduces gas permeability and increases the slag resistance of the lining; get cost savings, because the process of prefabrication of piece refractories disappears, complete units of almost any configuration, speed up the construction process and reduce the proportion of manual labor. The seams between the mullite-corundum increased-dense blocks of MKFPP-88 are filled with finely ground dry chamotte powder, and the author achieved even better results when the chamotte powder in the upper part, filled in the slots of the hearth and inclined platform, was filled with liquid glass and then “flush” covered with “flush” with the upper plane of the hearth and inclined area with refractory adhesive mastic.

As a binder, a refractory composition is used, consisting of refractory clay (23%), fireclay powder (73%), water glass (3%) and phosphon (aluminochromophosphate mixture, 1%).

The thickness of the seams is 1-2 mm, thermal expansion joints are not laid out. Four walls are laid on the metal frame 1 of the furnace, under 4, an inclined platform 5. The frame 1 of the furnace is poured with concrete of grade В22.5 with a filler - a crumb of lightweight fireclay brick. Surplus concrete B22.5 with a filler - a crumb of lightweight fireclay brick - is removed with a ruler from the surface of the frame 1. The horizontal part of the hearth 4 consists of seven rows of mullite-corundum increased-dense blocks MKFPP-88, three pieces in each row, the inclined part of the hearth 4 has three rows three pieces in each row, laid on a die. The size of the bottom is 3 × 2.8 meters. Inclined platform 5 consists of seven rows of hearth mullite-corundum increased-dense blocks MKFPP-88, laid on a die. The size of the inclined platform is 3 × 2.8 meters. Hearth blocks are lined with direct fireclay bricks of the ShA-1 brand, product No. 5 GOST 8691-73. The furnace walls are laid out of fireclay bricks SHA-1 No. 5 and No. 12 GOST 8691-73 in a steel box 11. In this case, the reflective furnace for remelting aluminum scrap has two slots in the rear 3 wall for the release of molten metal, made in quick-change summer bricks 12, moreover, each summer brick 12 is located in the welded box 13 of the summer brick 12, which has a flange with four holes for fastening to the steel box 11 of the furnace, in addition, the furnace has two lined rotary bowls 14 with lined rotary welds welded to them s 15 which may be rotated during the casting of the molten metal pouring and parallel weld metal in the furnace into the casting equipment. The rotary cup 14 has a welded bead 16 at the bottom, which enters the sleeve 17 and rotates therein, the sleeve 17 itself being welded to the bracket 18, the latter being welded to the frame 1.

As described above, each summer brick 12 is placed in the welded box 13 of the summer brick 12 and when laying the rear wall 3 is laid in a niche, while four studs 19 welded to the steel box 11, the ovens enter the flanging holes of the welded box 13 and are mounted on steel box 11 of the furnace with four nuts 20. On the welded box 13 of the summer brick 12 two handles (not shown) are welded, with which you can remove and put the summer brick 12, located in the welded box 13, in the niche of the furnace. Each letka is shut up by a peak. The furnace walls are laid out in two bricks.

A steel box 11 of the furnace is welded to the frame 1 of the furnace, having heat insulation between it and each wall, consisting of a double heat-insulating mullite grade MLF-260 fiberglass layer and sheet asphalt board 21. This design solution significantly reduces heat loss to the environment.

The steel box 11 of the furnace is fastened to the frame 1 of the furnace by vertical channels 22 No. 16.

To prevent the expansion of the masonry furnace vertical channels have a bunch of horizontal channels 23 No. 16 of figure 2, 3.

Working 24 and slag 25 windows have arches 26 and 27, respectively, laid out according to the templates from the chamotte end wedge ША-1 No. 22 and No. 23 of Fig. 2, 3. Further, the furnace has a hydraulic drive for raising and lowering the working damper 28 of the furnace, consisting of two power cylinders 29, an oil pump (not shown), four brackets 30 rotating in axles 31, welded on one side to the vertical channels 32, and on the other to the working damper 28 of the furnace. The furnace’s working flap is cast from heat-resistant cast iron of the ХX16 brand, has a double heat-insulating mullite grade MLF-260 with a fiberglass layer, lined with a lightweight one and a half fire-resistant brick of the brand ШЛ 0.9, and the lining protrudes 30 mm beyond the flap plane and, when closed, a reliable “L-shaped” lock ”, which helps to reduce fumes and heat loss from the furnace. The flap 33 of the slag 25 furnace window has a frame lined with a lightweight one-and-a-half brick of the ШЛ 0.9 grade, protruding 30 mm beyond the frame, the frame having two sliders 34 on each side, welded to it, moving along the copiers 35, while closing a reliable “L-shaped lock” is formed in the slag window, which helps to reduce fumes and heat loss from the furnace. The drive for raising and lowering the shutter 33 of the slag 25 furnace window consists of: an electric motor 36, a coupling 37, a worm gear 38, a drum 39, a counterweight 40, cables 41, pulleys 42 and a shutter 33 with a heat-insulating layer of FIGS. 1, 3.

A reflective furnace for remelting aluminum scrap is equipped with a lined 43 refractory brick with an afterburner 43, in which a four-mixing gas injection burner 44 of FIG. 9 is installed. The afterburner has a door 45 in the side wall for cleaning it from dust, soot, lined with lightweight fireclay brick, which opens and closes manually. Additionally, the necessary air for the combustion process is supplied by the blower 46 of FIG. 4.

At the same time, the gas duct 47 leaving the afterburning chamber 43 has a slide gate 48, which is manually raised and lowered by means of the counterweight 49 of FIGS. 1, 3, 9.

In addition, the reflective furnace for remelting aluminum scrap has two injection ten-mixing medium pressure burners 50 in one side wall, angled to an inclined platform 5, and in the other side wall one injection ten mixing torch 51 with a smooth internal surface of the mixers, angled at an inclined platform, and another 19 mixing 52, directed to the hearth 4 of the furnace of figure 1. The 19-mixing burner has seven mixers 53 with nozzles 54 in the center, which make it possible to obtain a 2.8-meter torch, the remaining 55 mixers are used without nozzles and have a 1.5-meter torch (the torch was studied in the laboratory of Penzaplav LLC at a research stand ) FIGS. 5, 6. Medium-pressure ten-mixing burners have five mixers 56 in the upper row, made with ribs 57 at their ends inside the central channel, which give a 2.4-meter long torch when burning the gas-air mixture, mixers 58 in the lower row, call lyayut receive the torch length 1.3 meters 7. A ten-mixing burner 51 with a smooth inner surface of the mixers, angled towards the inclined platform 5, has the same dimensions as the ten-mixing burners 50, like the mixers 58 located in the lower row of the previous burner, the mixers of the burner 51 make it possible to obtain a 1.3-meter torch of FIG. 8. The mixers of all burners have: inner diameter 42 mm, outer 66 mm, four nozzles with a diameter of 1.4 mm.

This arrangement of the burners allows to achieve a high melting rate, reduce fumes (according to practical data), as well as to load an uncontaminated charge through a slag 25 window and to quickly melt it due to the heat generated during the burning of the torch of the 19 mixing burner 52. The total thermal power of the burners is 6240 kW, which makes the furnace highly efficient, which allows forcing the forced melting mode, while the metal does not have time to oxidize and, ultimately, the waste is small. The shape and size of the burners are different, but the device is the same. So the nineteen-mixing medium-pressure burner, like the other three, has a burner tunnel 59 for stable flame burning, made of stainless chromium-nickel steel, and also a casing 60 for filling the gaps between the mixers with a refractory packing mass 61. Gas enters the gas distribution box 62 through the nozzle 63.

The nominal operating pressure of all burners is 0.08 MPa. When the furnace is lined in four openings, four injection burners are laid and are blocked by large mullite-corundum increased-dense blocks MKFPP-88. Then, the burners are lined with a refractory ramming mass of their own design, having the following composition:

Quartz sand;

Chamotte mortar МШ 39 ТУ 14-199-119-200;

Technical lignosulfonate TU 13-0281036-89;

Powder ground clay PHB TU 1522-009-00190495-99;

Foscon (aluminochromophosphate mixture) TU 2149-150-10964029-01

Large arch 64 is made according to the pattern (circles) of the wedge of the end ША1 No. 22, No. 23 and has a coating of 65, having the following composition:

- asbestos chips - 85%;

- liquid glass - 5%;

- refractory clay - 5%;

- sand - 5%

- water.

On top of the coating, a heat-insulating mullite of the MLF-260 grade was laid on a fiberglass layer 66 with a thickness of 30 mm, which further reduces heat loss from the furnace. Heel beams (not shown) are welded from channel No. 27.

Purification of flue gases from dust and harmful substances occurs in the installation of dust and gas purification, developed by the author and depicted in Fig.10, 11, which has a wide range of purified harmful substances in flue gases. Since the amount of flue gas generated during smelting in a furnace is large, two identical dust and gas cleaning units 67 are combined here into a single dust and gas cleaning structure, which has a service area 68 for preventive maintenance on blowers 69 and units 67, a service area 70 for loading adsorbent into dust and gas cleaning units 67 and a common staircase 71, along which the operator ascends to service sites 68 and 70. Each dust and gas cleaning unit is a prefabricated steel square sectional casing, in the lower h STI which has a carousel grating 72 with openings for filling her adsorbent. The rotation of the lattice around the axis is carried out using the handle 73 mounted on the axis 74. Above the rotary loading lattice is the loading pipe 75. Inside the upper part of the block 67 there are 18 filter cartridges that trap dust particles from flue gases.

In the upper part of the block 67, a service platform 68 is mounted on four brackets 76, which rests on four supports 77. On the service site 68, a frame 78 is mounted on which a blower 79 with an electric motor 80 of FIG. 11 is mounted. The spent adsorbent and dust are collected in the lower part 81 of block 67. The cleaned gases are supplied to each block 67 of the dust and gas cleaning installation through nozzles 82. After the dust and gas cleaning installation has been working for 5 days, turning the handle 73 of the charging grill 72 of each block 67, the spent adsorbent (activated carbon, silica gel, birch charcoal, fluff lime) is poured into the lower part 81 of block 67. Then it is necessary to turn the handle 83 of the nozzle for unloading, while the spent adsorbent and dust from the cartridges are poured from the lower part 81 of block 67 into t aru 84. For servicing cartridge filters, there is a laz at the top of block 67, which is closed by a cover 85. The cleaned flue gases are supplied through a pipe 86 to the blower 79. In accordance with the requirements of t / b, service areas 68 and 70 have a fence 87. The main technical characteristics of the dust and gas cleaning installation are:

- productivity on the purified gas of 18 800 m ³ / h;

- filtering surface area of 24.8 m ² ;

- the number of cartridge filters 18 pcs .;

- the thickness of the adsorbent layer is 0.3-0.35 m;

- the degree of purification by hydrogen fluoride 73%;

- the degree of purification of copper oxide 87%;

- the degree of purification of carbon monoxide 94%;

- the degree of purification of nitric oxide 86%;

- the degree of purification of aluminum oxide 81%;

- degree of dust cleaning 94%;

- temperature of the purified gas from 20 to 100 ° C;

- temperature of the outer surface of the installation

from 45 to 55 ° C;

- sound level no more than 80 dBA;

- energy costs for cleaning 6 kW / h.

Before installing the dust and gas cleaning, a mixing chamber 88 is installed, in which the gate 89 is used to control the supply of flue gases to the dust and gas cleaning installation, and the gate 90 is used for the process of mixing flue gases with the air of the workshop of Fig. 12. The DN-12 91 smoke exhauster is used to pump flue gases into the dust and gas cleaning installation, a gate 94 is installed on the pipe 93 before the entrance to the chimney 92, and a gate 96 is installed on the metal duct 95. A service area 97 with a ladder 98 is provided for servicing the gate 94 and 96. gate 94 on the pipe 93 has a gate 99.

The furnace operates on natural draft as follows.

The smelter of metal and alloys opens the gates 94 and 99, the gates 89 and 96 are closed, while the thrust in the furnace should be 2-20 daPa. Gas is supplied, burners are turned on and the furnace is calcined according to the technological schedule of calcination, depending on the type of repair. After calcination, the mechanism for raising the shutter of the working window 24 is turned on and aluminum scrap is loaded into the calcined furnace on an inclined platform 5 through the working window 24. The flame of three gas injection burners 50, 51 heats the scrap to its melting point. The metal melts and flows down an inclined platform 5 to a 4 furnace. As molten metal accumulates on the hearth 4 of the furnace, scrap is loaded into the slag window 25, which is melted by the torch of the burner 52. The hot flue gases rise and enter the afterburning chamber 43, in which they are burned and removed through the pipe 93 into the atmosphere through the chimney 92. The coating layer 65 of the large arch 64, mullite heat-insulating mullite of the MLF-260 grade, glass fiber layer 66, 30 mm thick, thermal insulation of walls, hearth 4, inclined platform 5 and heat-insulating layers on the furnace frame 1 provide high thermal insulation of the melting unit. At the same time, the concrete frame of the furnace with a filler - crumb of lightweight fireclay brick, heat-insulating mullite grade MLF-260 fiberglass layer 7 and lightweight brick ШЛ-0,9 8 provide additional thermal resistance to the heat flux emanating from the inclined platform 5 and bottom 4 down to the foundation. During the melting process, the scrap melts, and on the inclined platform 5, all inclusions remain, the melting temperature of which is higher than the aluminum alloy. These wastes (alterations: cast iron and steel rings, liners, bushings, studs, pushers, valves, etc.) do not fall into the molten metal, since at the end of the heat they are removed from the inclined platform with a scraper fixed to the loader. After the molten scrap loaded into the furnace is completely melted, the liquid metal is flux-treated, the metal is thoroughly mixed in the bath and the spectral analysis laboratory confirms the grade of the alloy obtained, the metal fillers open the notch and pour liquid metal into the molds of the casting carousel 100 and casting conveyor 101. After casting from the furnace liquid metal, the metal smelter opens the shutter 33 of the slag window 25 and cleans the bottom 4 of the slag and accidentally caught alterations on it.

The operation of the furnace on artificial draft is as follows.

The smelter of metal and alloys closes the gate 99 and the gate 94, while the gates 89, 96 are open. The operations are carried out the same as during natural draft melting. The difference is that before loading the charge into the furnace, the adsorbent is loaded from the service site 87 into the dust and gas cleaning unit and it is turned on, in addition, the smoke exhauster 91 is turned on. The combustion products, having passed through the mixing chamber 88, are diluted in it with the workshop air, then they are cleaned of dust and harmful compounds in the dust and gas cleaning installation and are pumped by the exhaust fan 91 and blowers 79 through a metal duct 95 into the chimney 92.

The principle of operation of the dust and gas cleaning installation is as follows: the flue gases pass through the adsorbent layer on the charging grates 72, and a “fluidized bed” forms, as a result of which the harmful substances in the flue gases are adsorbed by lime with a fluff, activated carbon, silica gel, and birch coal. After purification of flue gases from harmful substances, they are cleaned of dust in 18 cartridge filters. Every 5 days, the spent adsorbent is replaced with a new one.

Claims (7)

1. Reflective furnace for remelting aluminum scrap, containing a housing formed by refractory outer side, front and rear end walls, an accumulation bath bounded by a hearth and walls, a vault, a drain door, a gas duct, characterized in that the furnace body is placed on a welded frame filled with concrete filled with crumb of lightweight fireclay bricks, while the storage bath and inclined platform are made of mullite-corundum blocks of increased density MKFPP-88, laid on a heat-insulating mullite stack a fiberboard layer of the MLF-260 grade and lightweight brick ШЛ-0,9, a steel box is welded to the furnace frame, provided with heat insulation between it and each wall, consisting of a double heat-insulating mullite fiberglass layer of the MLF-260 grade and sheet asphalt board, while the furnace has one side wall two injection ten-mixing burners of medium pressure directed at an angle to an inclined platform, in the other side wall one injection ten mixing mixer burner with a smooth inner surface of the mixers, angled on an inclined platform, a nineteen-mixing burner, directed to the bottom of the furnace, a lining of a refractory brick the afterburner, in which a gas four-mixing injection burner with nozzles is installed, and the afterburner has a door in the side wall lined with a lightweight fireclay brick, which opens and closes manually and a blower is placed on top, while the furnace has a working and slag windows. 2. The furnace according to claim 1, characterized in that it has a hydraulic drive for raising and lowering the working damper of the furnace, consisting of two power cylinders, an oil pump, brackets rotating on axes welded to the furnace body, and a cast iron damper with double heat-insulating mullite a fiberglass layer of the MLF-260 brand lined with a lightweight one and a half refractory brick, and the lining extends beyond the damper plane by 30 mm with the formation of a reliable L-shaped lock when closing to reduce fumes and heat loss from the furnace. 3. The furnace according to claim 1, characterized in that the slag window of the furnace has a frame lined with a lightweight one and a half brick protruding 30 mm beyond the frame, the frame having two sliders on each side, welded to it, moving along the copiers, with the formation of a reliable L-shaped lock when closing the slag window to reduce fumes and heat losses from the furnace, and the drive for raising and lowering the slag window shutter of the furnace contains an electric motor, a coupling, a worm gearbox, a drum, a counterweight, cables and pulleys. 4. The furnace according to claim 1, characterized in that it has two slots in the end rear wall for the release of molten metal, made in quick-change bricks, each bricks is placed in a welded box bricks, which has a flange with four holes for fastenings to the furnace box, and two lined rotary bowls with lined rotary troughs welded to them, made with the possibility of rotation during the casting of liquid metal with the provision of casting the weld metal in the furnace waste equipment. 5. The furnace according to claim 1, characterized in that the arch has a refractory heat-insulating coating and a heat-insulating mullite glass fiber layer of the MLF-260 grade 30 mm thick is laid on top of it. 6. The furnace according to claim 1, characterized in that it is equipped with a dust and gas cleaning installation, consisting of two identical units combined into a single design, two rotary grilles and eighteen cartridge filters are placed in the blocks, while the dust and gas cleaning installation has a service platform for preventive maintenance on blowers and blocks serving the site for loading the adsorbent into the dust and gas cleaning blocks and a common staircase for the sites. 7. The furnace according to claim 1, characterized in that the nineteen-mixing burner has seven mixers with nozzles in the center that provide a 2.8-meter long torch, and the remaining mixers without nozzles with a 1.5-meter torch, two ten-mixing torches have a top in a row there are five mixers made with ribs at their ends inside the central channel to receive a 2.4-meter long torch when burning a gas-air mixture, and the mixers located in the bottom row provide a 1.3-meter torch.

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