RU2407969C1 - Reverberating furnace for metal remelting - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: reverberating furnace consists of case formed with refractory external side, front and back end walls, of storage bath and tilted platform restricted with hearth and walls, of discharge notch, of turning-rotary chute, of gas duct and of welded frame poured with concrete with filler of chamotte chips and having two heat insulating layers out of light-weight brick under bottom and three heat insulating layers out of light-weight brick under tilted platform. In side walls there two loading and two slag windows. Devices for doors lifting and lowering facilitate reliable pressure tightness forming a L-shaped lock. Two rows of gas injection burners of medium pressure are installed in the furnace; also, the lower row of the burners is directed into charge, while the upper one is directed onto the bath. The furnace can operate on natural or forced draught with system of powder-gas cleaning. The turn-rotary chute consists of three connected telescopic sections arranged on a carriage and rotating in the process of liquid metal casting, and of a revolving cup with a lip. The revolving cup is mounted on a channel coaxially to the rotating chute and has a metal case with refractory and heat insulated layer under it. From beneath to the metal case of the revolving cup there is welded a shaft resting on a support ball and facilitating turn of the revolving cup at angle of 120° for successive casting of melt metal into casting equipment installed in a sector at angle of 120°.

EFFECT: re-melting scrap, non-graded from foreign inclusions, and reduced burn-off and heat losses in furnace.

8 cl, 4 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 smelting metal (Information source - RF patent No. 2155304), comprising a housing formed by masonry of the external walls as in the claimed furnace, a storage bath and an inclined platform bounded 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. The furnace uses a stationary chute to drain molten metal.

5. 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), containing a housing formed by brickwork of the external walls as in the claimed furnace, a storage bath and an inclined platform limited by the hearth and walls, a vault, a drainage drain and a gas duct.

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. 2361161), 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, bounded by a hearth and walls, a vault, a drainage notch and a gas duct, the housing being placed on a welded frame. I believe that the oven, taken as a prototype, has the following disadvantages:

1. External thermal insulation of the walls, the arch, as well as the storage bath and the inclined platform is good, but it can be improved;

2. The furnace is not highly productive;

3. The furnace has satisfactory tightness. Due to the special design of the shutters for 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 uses a stationary chute for draining molten metal;

5. The hearth blocks ShSU-33-1 GOST 7151-74, having a sufficiently long service life, are used in the furnace, however, by using other hearth blocks for the hearth and inclined platform, the service life can be increased.

The objective of the invention is the creation of a high-performance gas bath of a reflective type furnace for remelting aluminum scrap of a simple design, sealed, which allows to reduce emissions of harmful gases into the atmosphere, reduce metal and heat losses into the environment, as well as increase its life and introduce a rotary-rotating furnace gutter.

EFFECT: developed furnace is simple in design, hermetic, having a long service life, highly productive, allowing to use scrap unsorted from foreign inclusions, to reduce heat loss to the environment due to special thermal insulation, to conduct the remelting process on natural and artificial draft with a dust and gas cleaning system, 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, poured concrete with filler fireclay chips and having two heat-insulating layers of lightweight brick under the hearth and three under the inclined platform. Concrete filled with fireclay chips, two heat-insulating layers of lightweight bricks under the bottom and three under an inclined platform can reduce heat loss.

In addition, the storage bath and the inclined platform are made of the bottom blocks of the ВШБС No. 1 ТУ 1547-033-00187027-2005, laid on four layers of asbestos-cardboard, and are tamped with chamotte powder mixed with crushed asbestos chips. The service life of the furnace is increased due to the use of the bottom blocks VShBS No. 1 TU 1547-033-00187027-2005, which have high refractoriness and durability (the service life is 6-7 years according to practical data). By using the VShBS blocks No. 1 TU 1547-033-00187027-2005 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, speed up the construction process and reduce the proportion of manual labor.

Thermal insulation, consisting of four layers of asbestos board and a chamotte powder kneading mixed with crushed asbestos chips, allows you to further maintain the temperature of the metal in the bathtub and the inclined platform.

It should be noted that the proposed reflective furnace for remelting aluminum scrap has two loading and two slag windows located in the side walls to provide front loading of the furnace from two sides. Compared to the prototype, the bath in the proposed furnace is larger and deeper, therefore, the design has two slag windows through which it is possible to quickly clean the bath from alterations, slag, and to process the flux of molten metal from both sides faster. The inclined platform is also larger in size, and in order to accelerate the loading of the charge into the furnace, two loading windows are provided through which loading is carried out from two sides. Due to the aforementioned, in the regulation of the technological process more time is devoted to smelting, the furnace smelts more aluminum scrap.

At the same time, the reflective furnace for remelting aluminum scrap has two rows of medium-pressure injection burners in the front (burner) wall, and the lower row of burners in the amount of five pieces BIG 2-8 TU 51-464-89 is directed to the charge located on an inclined platform and the top row of burners in the amount of three pieces with a long torch is directed to the bath with molten metal. 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 slag windows and to quickly melt it due to the heat generated during the burning of the torches of the upper row of burners. The thermal power of the burners is 6144 kW, which makes the furnace highly productive, allowing for forced melting.

In this case, the reflective furnace for remelting aluminum scrap has a rotary-rotating chute that rotates during the casting of liquid metal and has a rotary bowl in the design, which allows sequentially pouring the metal deposited in the furnace into casting equipment located in the service sector with an angle of 120 °. The closed design of the swivel-rotating chute for pouring molten metal dramatically reduces heat loss and gas generation, improves the working conditions of staff, the lining wears out gradually and evenly over the entire inner surface of the chute.

Moreover, a steel box is welded to the furnace frame, which has heat insulation between it and each wall, consisting of asbestos chips, refractory wool, refractory mats, a layer of sheet asbestos board. This design solution significantly reduces heat loss to the environment.

It is important to note that the furnace arch has a triple refractory heat-insulating coating and a layer of refractory heat-insulating mats is laid on top of it. This further reduces heat loss from the furnace.

In addition, the furnace has four drives for raising and lowering the furnace dampers, each consisting of an electric motor, a clutch, a worm gear, a pulley, a chain, a cable, a counterweight, copy machines and a damper with a triple heat-insulating layer of asbestos lined with a lightweight one and a half refractory brick that protrudes beyond a frame of 50-60 mm and forming a reliable "L-shaped lock" when closing, which helps to reduce fumes and reduce heat loss.

Finally, a threshold is made below the gas duct in the furnace. It is designed to provide secondary heating of liquid metal in the bath.

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

The presence of an inclined platform allows the melting of scrap unsorted from foreign inclusions in the furnace, since alterations (cast iron and steel rings, liners, bushings, studs, pushers, valves, etc.) do not fall into the molten metal.

Figure 1 is a longitudinal section of a furnace.

Figure 2 is a transverse section of the furnace (view of the burner belt).

Figure 3 is a transverse section of the furnace (view of the notch and chimney).

Figure 4 is a plan view of the furnace.

The proposed furnace contains a housing 1 mounted on the frame of the furnace, formed by brickwork from fireclay bricks. The housing 1 is mounted on a metal frame, in the inner cavity of the metal frame on a heat-insulating cushion 2 made of concrete with chamotte filler, an accumulative bath is located, limited by the hearth 3 and walls 4 made of fireproof chamotte brick ША1. A bathtub with a depth of 400 mm is limited by the inclined platform 5, which is the loading table. Above the storage bath and inclined platform 5, a large vault 6 is assembled, resting on the side walls 4. A small vault 7 is made above the loading window and rests on the heel bricks 8 (ША1 No. 67). The metal frame is poured with concrete with chamotte filler filler 9. Over the inclined platform 5, loading windows 10 are made on two sides in the furnace body 1. A gas duct 11 is laid out in the rear wall of the furnace 11, a notch 12 is located at the bottom, two sides of which are laid in the side walls 4 of the housing slag windows 13 for removing slag from the surface of the molten metal. For the flow of molten metal into the groove 12 and for the convenience of cleaning the groove in the process of removing alterations and slag from the hearth 3, there is a channel (recess) 14 in front of the groove that is made in the hearth block by a “grinder” during the lining of the furnace. The front (burner) wall 15 of the furnace is laid out in two bricks, the rear (flight) wall 16, and the rest in two and a half. A metal frame with a furnace is installed on the concrete floor of 17 workshops. The heat-insulating pillow 2 has a bottom layer 18, which is a row (layer) of lightweight brick. A layer of lightweight brick is located at a distance of 120 mm from floor 17 of the workshop. The second row (layer) 19 of lightweight brick is located from the first row at a distance of 180 mm. There are steel blooms in the analogue, in the proposed furnace design, the metal frame has cross-members in the form of channels, which partially serve as blooms 20, have sufficient heat capacity and are in concrete with chamotte filler 9. Under the inclined platform 5, there is a heat-insulating layer 21 in the metal frame, consisting of one row of lightweight bricks. The gap 22 between the upper surface of the metal frame and the heat-insulating layer 21 has a size of 260 mm. In the duct 11 there is a control flap 23. In the front (burner) wall 15 of the furnace, channels (openings) 24 and 25 are made for placing the burners in them.

Under the furnace 3 and the inclined platform 5 are laid out of the bottom blocks VShBS No. 1 TU1547-033-00187027-2005 (thickness 300 mm, width 400 mm, length 1000 mm). The use of blocks ВШБС №1 instead of ordinary piece products can reduce the number of joints, 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 WSFS blocks No. 1 are filled with finely ground dry chamotte powder, and an even better result was achieved by the author when the chamotte powder poured into the slots of the hearth blocks and the inclined platform was filled with liquid glass in the upper part and then “flush” with the upper plane of the hearth and inclined area with TRIUMF refractory adhesive mastic. Bottom blocks ВШБС №1 ТУ1547-033-00187027-2005 (thickness 300 mm, width 400 mm, length 1000 mm laid on a metal frame and have a knockout made of chamotte powder mixed with crushed asbestos chips, on top of which 4 mm thick four-sided cardboard is laid layer 26, Fig. 1. The service life of the furnace is increased due to the use of the bottom blocks VShBS No. 1, which have high refractoriness and durability (service life according to practical data 6-7 years). Thermal insulation, consisting of four layers of asphalt board and chamotte tamping powder mixed with crushed as shake crumb, allows you to further maintain the temperature of the metal in the bathtub and an inclined platform.

As a binder, a refractory solution is used, consisting of refractory clay (21%), fireclay powder (75%), water glass (3%) and phosphon (aluminochromophosphate mixture, 1%).

The thickness of the seams is 1-2 mm, thermal expansion joints are not laid out. The metal frame of the welded furnace, welded from I-beams No. 24, 36 and (27) of channel No. 14, is poured with concrete of grade B40 with chamotte filler to reduce heat loss through the concrete of the frame to the floor of the workshop. When pouring B40 concrete with chamotte filler, the rows (layers) of lightweight brick are laid, then excess B40 concrete with chamotte filler is removed with a ruler from the surface of I-beams No. 36 and No. 24. After hardening of concrete B40 with a filler of fireclay chips, a chock of chamotte powder mixed with crushed asbestos chips is made under the furnace hearth and inclined platform. The hearth consists of six rows of hearth blocks VShBS No. 1 TU 1547-033-00187027-2005, three pieces in each row, laid on a "die". The size of the hearth is 2.4 × 3 meters. The inclined platform consists of six rows of the bottom blocks of the VShBS No. 1 TU 1547-033-00187027-2005 laid on the “rib”. The size of the inclined platform is 3 × 1.8 meters. Hearth blocks are lined with direct fireclay bricks of brand ША 1 product No. 5 GOST 8691-73. The furnace walls are laid out of fireclay bricks ША 1 product No. 5 and No. 12 GOST 8691-73. In the lower central part of the rear wall 16 there is a notch 12 drilled in the summer brick 28. The summer brick 28 is placed in the metal box of the summer brick and when laying the rear (summer) 16 wall, it is laid in a niche and fixed with wedges in it (not shown).

When replacing a worn summer brick 28, the metal box of the summer brick with the inside brick 28 is removed from the niche, the old summer brick 28 is removed, the new summer brick 28 and the metal summer brick with the new summer brick 28 installed in it are inserted into the metal box of the summer brick 28 put in a niche.

A steel box is welded to the furnace frame, which has thermal insulation between it and each wall, consisting of asbestos chips, refractory wool, refractory mats, a layer of sheet asbestos board. This design solution significantly reduces heat loss to the environment.

The walls of the furnace body 1 are laid out in a steel box. The fastening of the steel box to the metal frame is made by vertical channels No. 20 (29), Figure 1.

To prevent the expansion of the masonry furnace vertical channels have a bunch of horizontal channels No. 20 (30), Figure 1.

Slag windows 13, as well as loading 10, have arches 31 and 7, respectively, laid out according to the patterns in 5 rows of chamotte end wedge ША 1 No. 22 and No. 23, Fig. 1. The masonry of the set of loading and slag windows stands for a 60 mm steel box. In the front wall 15 there are five openings for five injection burners BIG 2-8 TU 51-464-89 (32), Figure 1, which are directed to the charge located on the inclined platform 5. The burners are located at an angle to the inclined platform 5 of the furnace and bottom 3, which allows more complete use of heat when burning fuel to heat the mixture and its melting. Each burner has a burner tunnel for sustainable torch burning.

The nominal operating pressure of the burners is 0.08 MPa. When the furnace is lined in five openings, five injection burners of the lower row of the BIG 2-8 TU 51-464-89 are stacked and overlapped by the VShBS units. Then the burners are washed with a special refractory ramming mass of their own design, having the following composition:

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;

Water

The process of preparing a special refractory packing mass is as follows: the powder is soaked in ground clay for a day, then chamotte mortar is added in portions and the whole mass is constantly thoroughly mixed, technical lignosulfonate is added and everything is thoroughly mixed. In conclusion, with stirring, the phosphon and water are poured into the mixture.

After setting the burners of the lower row 32, they are calcined for 40-60 minutes with a portable burner, the final calcination is carried out together with the furnace.

Above the lower row of burners, three openings are laid out under three injection burners 32, each having eight mixers directed to the hearth and giving a long torch when burning the air-gas mixture (patent No. 2365816, author V. Trusov). Moreover, the burners have a duct, a burner tunnel and complete mixing of the gas-air mixture. Before installation, the burners are calcined outside the furnace, and during installation, only the gaps formed between the masonry of the opening and the burner box are closed. The burners are guided to the hearth and are blocked by the HSBS blocks. This arrangement of the burners allows to achieve a high melting speed, reduce fumes. The mixture, thrown into the bathtub through slag windows, is very quickly melted by the burners 32 of the upper row directed at it. The thermal power of the lower row burners is 3840 kW, the upper row 2304 kW. Such a large thermal power leads to a forced melting mode, while the metal does not have time to oxidize and, ultimately, the waste is small.

Heel beams 33 are welded from channels No. 30.

The furnace can operate on natural traction with the power off due to the use of eight injection burners.

- Large arch 6 is made according to the pattern (circles) of the wedge of the end ША1 No. 22, No. 23 and has a coating 34, Figure 2, in three layers. First, the first coating layer is applied, having the following composition:

- asbestos chips - 90%;

- liquid glass - 5%;

- refractory clay - 5%;

- water

After drying the first coating layer, a second layer of 20 mm thickness is applied, which has the following composition:

- refractory clay - 5%;

- fireclay powder - 90%;

- liquid glass - 5%;

- water

The second coating layer is dried and a third layer 30 mm thick is applied, which has the following composition:

- sand - 40%;

- asbestos chips - 50%;

- liquid glass - 10%;

- water

A layer of refractory heat-insulating mats is laid on top of the coating, which further reduces heat loss from the furnace.

The flue 11, Figure 2, has an arched vault and a regulating flap 23, regulating traction (artificial and natural). It is important to note that the furnace can operate both on artificial draft and on natural draft. When using dust and gas cleaning plants, the process becomes environmentally friendly. Behind the side wall of the boarhouse workshop, it bifurcates: one straight branch goes to the chimney 35, the other (oblique boar) 36 to the mixing chamber, smoke exhauster and dust and gas cleaning, Figure 4. The borovka branch, going to the exhaust fan, has a mixing chamber in which two gates are installed: one of which 37 closes or opens the supply of exhaust gases to the exhaust fan, the other 38 regulates the supply of fresh air to dilute the combustion products with it, Figure 4. The same valves (gates) regulate the amount of vacuum in the furnace, which is 2-20 daPa.

After cleaning from dust and harmful gases, the combustion products through the metal return duct 39 are pumped by the smoke exhauster 40 and blower 41 into the chimney 35. During artificial draft, the vacuum is created by the DN-9u exhaust fan, which has an operating temperature of up to 250 ° C, while the flue gases the entrance to the hog has a temperature of 950-1050 ° C. To reduce the temperature of the flue gases, a mixing chamber 42 is installed in which the hot flue gases are mixed with the air of the workshop, as a result of which the temperature of the flue gases becomes 160-200 ° C. Gate 43 regulates natural traction, and gate 44 regulates artificial traction. Industrial dust and gas cleaning 45 has a wide range of purified harmful substances in flue gases and the degree of purification is 75-98%. As a rule, they have a service platform on which the operator climbs the stairs (as shown in Figure 4).

Smelted metal is poured from the furnace through a swivel-rotating trough. The swivel-rotating chute contains a stationary drain sock 46, a swivel bowl with a sock 47, a rotating lined chute for casting molten metal 48. The chute is made of three cone-shaped sections connected by bolts 49 and wing nuts 50 and installed together with the drive on a trolley 51 with adjustable in height, uprights 52 and articulated-swivel wheels 53, allowing the swivel-rotating trough to rotate 120 ° and change its height. The turntable with toe 47 has two handles that use metal fillers to rotate and dock it with sections of the rotary-rotating trough. The rotary bowl with the toe 47 has a metal body 54 with a lining 55. From the bottom, a shaft 56 is welded to the metal body 55 of the rotary bowl with the toe 47 and is supported by a ball 57 located at the bottom of the pipe 58 with a bottom. The pipe 58 is vertically welded to the channel 59 with the possibility of rotation of the bowl at an angle of 120 ° around its axis. The trough sections rotate from an electric drive consisting of an electric motor 60, a coupling 61, a reducer 62, a gear wheel 63. On the trolley 51 there is a frame 64 for fastening the electric motor 60. In the assembled state, the rotary-rotating trough rims 65 rests on the track rollers 66, which rotate in the axles 67 mounted on the brackets 68. The gear wheel 63 is engaged with the gear wheel 69 fixedly mounted on the middle section of the rotary-rotating trough. The trolley 51 has two stop screws 70 for fixing it during casting from the weld metal deposit. The trolley 51 has four handles 71 for manual transportation. Thanks to the rotary-rotating chute, it is possible to sequentially pour metal deposited in the furnace into casting equipment located in a sector with an angle of 120 ° (for example, into a large bucket 72, casting carousel 73, casting conveyor 74). The closed design of the swivel-rotating gutter sharply reduces heat loss and gas generation, improves the working conditions of staff, the lining gradually wears out uniformly over the entire inner surface.

Reflective furnace for remelting metal has four devices for raising and lowering the slag shutters and working windows. The device for raising and lowering the furnace shutter consists of an electric motor 75, a coupling 76, a worm gear 77, pulleys 78, a chain 79, a cable 80, a counterweight 81, a copier 82, a shutter. The damper consists of a welded frame 83, has two welded nozzles 84, which are supported by two copiers 82 and with the help of the actuator, the damper can be moved up and down opening and closing the window (slag or working). When closing the window 10, the damper rests on the bottom of the window sill 85. The damper has a back wall 86, a triple insulating layer of sheet asbestos 87 and is lined with one and a half lightweight bricks 88. A triple insulating layer of sheet asbestos 87 and a lightweight one and a half bricks 88 significantly reduce heat loss. It is important to note that the refractory lining of the shutter (lightweight brick) 88 protrudes beyond the plane of the welded frame 83 (by 50-60 mm) and, when the window is closed, enters the opening of the furnace, a reliable “L-shaped lock” is formed, which prevents gas from escaping from the furnace to the outside . The refractory lining 88 protruding beyond the welded frame 83, in addition to performing the tightness function, performs the function of protecting the metal structure of the welded frame 83 of the furnace flap from the action of hot furnace gases, which cause it to warp and form gaps and leaks. The tightness of the shutter closure of the furnace window is provided by the entrance of the copiers 82, which has an angle of 35 degrees.

Below the gas duct in the furnace, threshold 89 is made. It is designed to provide secondary heating of liquid metal in the bath. The burners 32 of the lower and upper rows are installed obliquely, so the flame of the burners is tilted at an angle to the inclined platform 5, the bath and it seems to slide along the charge and the bath with molten metal, smoothly bends around the back wall 16 and the threshold in it, then, twisting, rises to large arch 6, flows around part of it in the opposite direction, passes a second time on the surface of the liquid metal, providing its secondary heating. In the process, heat is accumulated in a large vault 6, from where it is reflected on the metal.

The furnace operates on natural draft as follows. The smelter of metal and alloys opens the control flap 23 and the gate 43, while the thrust should be 2-20 daPa. Gate 44 is closed. The burners are turned on and the furnace is calcined according to the technological schedule of calcination, depending on the type of repair. The mechanisms for raising the shutters of the working windows 10 are turned on, and the metal and alloy smelters on the inclined platform 5 are fed into the calcined furnace through the loading window 10, unbroken aluminum scrap with ambient temperature is loaded. The flame of the five gas injection burners 32, FIG. 1, heats the scrap to the melting point. The metal melts and flows down an inclined platform 5 into the furnace bath. The burners of the lower row are installed obliquely, so the flame of the burners of the lower row is tilted at an angle to the inclined platform 5 and it seems to slide along the charge lying on the inclined platform and melt the mixture. Burners of the upper row having a long torch are installed obliquely to the bath with molten metal, so the flame of the burners of the upper row slides along the bath with molten metal hits the back wall 16, then, twisting, rises to the large arch 6, flows around part of it in the opposite direction, passes for the second time on the charge and the surface of the liquid metal in the bath, providing its secondary heating. In the process, heat is accumulated in a large vault 6, from where it is reflected on the metal. Coating layers 34 of the arch, thermal insulation of walls, a hearth, an inclined platform 5 and heat-insulating layers of the furnace frame, tamping of chamotte powder mixed with crushed asbestos chips, and four layers of asbestos board 26 provide high thermal insulation of the melting unit. At the same time, the concrete of the furnace frame with the filler of fireclay chips 9 and layers of lightweight brick 18, 19, 21 provides additional thermal resistance to the heat flux emanating from the inclined platform and the bath down. The thermal efficiency of the furnace is above 65%. During the melting process, the scrap melts, the moisture in it evaporates, decomposing into oxygen and hydrogen, and all inclusions remain on the inclined platform 5, 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 enter the molten metal, since at the end of the smelting they are removed with a scraper from the surface of the inclined platform 5 to the slag. 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 bring the first section of the rotary-rotating chute to the tip of the rotary bowl 47 so that the toe enters the first section, and the trolley is unfolded and, let us say, lead to the large bucket 72 by the edge of the third section. The trolley is fixed on the floor of the workshop with stop screws 70 and the rotation drive of the rotary-rotating trough but. Next, the metal fill opens the notch 12 and casts the molten metal into a large ladle. Thus, molten metal from the furnace can be poured through a rotary-rotating chute into casting equipment located in a sector with an angle of 120 ° (also into casting carousel 73 and casting conveyor 74). After casting from a liquid metal furnace, metal and alloy smelters include actuators for lifting slag window dampers 13, raise slag window dampers and clean bottom 3 of slag and alterations accidentally caught on it. The operation of the furnace on artificial draft is as follows.

The smelter of metal and alloys closes the gate 43, and the gates 37, 38, 44 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 into the dust and gas treatment unit 45 and it is turned on. Combustion products, having passed through an inclined bore 36 and mixing chamber 42, are awakened (diluted) in it by the air of the workshop, then they are cleaned of dust and harmful compounds in the dust and gas cleaning unit 45, pumped by a smoke exhauster 40 and blower 41 through a metal return duct 39 into a chimney 35. Flue gas cleaning makes the process environmentally friendly.

The operation of the furnace on natural draft is carried out if the dimensions of the sanitary protection zone of the enterprise allow, during calcination, casting of deposited metal or during a power outage, when the operation of the smoke exhauster and dust and gas cleaning system is impossible.

After casting the liquid metal, the bath is cleaned of slag, the tap hole 12 is plugged and the cycle repeats.

So, the proposed furnace is simple in design, hermetic, having a long service life, high-performance, having low heat loss to the environment due to special thermal insulation.

Claims (8)

1. Reflective furnace for remelting aluminum scrap, containing a housing formed by refractory outer side, front and rear end walls and a vault, a storage bath with an inclined platform bounded by a hearth and walls, a drain passage and a gas duct, characterized in that the housing is placed on a welded frame, filled with concrete with chamotte filler and made with two heat-insulating layers of lightweight brick under the bottom and three under the inclined platform, while the furnace is equipped with a rotatable ohm which rotates during casting of liquid metal, with a rotary cup for serial casting weld metal in the furnace into the casting equipment located in the service sector of 120 °. 2. The furnace according to claim 1, characterized in that the storage bath and the inclined platform are made of the bottom blocks of the ВШБС No. 1 according to TU 1547-033-00187027-2005, laid on four layers of asbestos board, and have a tamping made of fireclay powder mixed with crushed asbestos chips. 3. The furnace according to claim 1, characterized in that two loading and two slag windows are placed in the side walls to provide front loading on both sides of the furnace. 4. The furnace according to claim 1, characterized in that it has four devices for raising and lowering the furnace dampers, each of which consists of an electric motor, a coupling, a worm gear, a pulley, a chain, a cable, a counterweight, copiers and a damper with a triple heat-insulating layer of asbestos lined with a lightweight one and a half refractory brick, protruding beyond the frame by 50-60 mm and forming a L-shaped lock when closing to reduce fumes and reduce heat loss. 5. The furnace according to claim 1, characterized in that the arch has a triple coating and a layer of refractory mats is laid on top of it to further reduce heat loss from the furnace. 6. The furnace according to claim 1, characterized in that a steel box is welded to the furnace frame, having heat insulation between it and each wall, consisting of asbestos chips, refractory wool, refractory mats, a layer of sheet asbestos board. 7. The furnace according to claim 1, characterized in that it has two rows of medium-pressure injection burners in the front wall, and the lower row of burners in the amount of five pieces of BIT 2-8 according to TU 51-464-89 is directed to a charge located on an inclined area, and the top row of burners in the amount of three pieces with a long torch is directed to the bath with molten metal. 8. The furnace according to claim 1, characterized in that a threshold is made in the flight wall below the gas duct to provide secondary heating of the liquid metal.

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