RU2398167C1 - Device for furnace shutter lifting and lowering - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: device for furnace shutter lifting and lowering consists of drive connected with shutter by means of flexible link, of water-cooled box and of restricting stops at furnace window; also shutter rests on restricting stops. Further, the device consists of a protective screen. The electric drive corresponds to a motor-reducer containing a doubled block of rollers and two single blocks of rollers interconnected with a flexible link in form of chains and a counterweight. Notably, shafts of doubled and single blocks of rollers are secured in slots of furnace plates facilitating transfer of the shutter along the water-cooled box and control of its position from a control panel. The water cooled box with the chain form 1° angle with vertical. The shutter contains "П"-shaped box with internal ribs and cover. It is cast out of heat-resistant iron with ribs and T-shaped cavities lined with refractory ramming mixture.

EFFECT: simplified design facilitating high operational reliability and pressure tightness.

2 cl, 8 dwg

Description

A device for raising and lowering the furnace shutter belongs to the field of equipment for heating furnaces and can be used in reflective-type bathrooms for melting aluminum alloys.

A known analogue is a device for lifting the damper of a heating furnace (source of information AS No. 1252638), containing a damper as in the claimed device, which moves up and down, closing and opening the window of the furnace. The flap in the lower position, as in the filed application for the alleged invention, relies on the threshold (window sill) of the furnace window.

The disadvantages are that:

- the device has a damper that does not fit snugly to the window frame of the furnace, and this leads to large heat losses;

- the use of a two-arm leverage system with counterweights makes the design large in size.

Of the known closest in technical essence (prototype) is a device for raising and lowering the damper of the furnace (RF patent No. 2229075), containing, as in the present invention, a drive with a flexible connection, a protective screen. Another common feature in devices is that the damper moves up and down, opening and closing the furnace window. In the raised upper position, the shutter is located opposite the protective screen, and in the lower - working position - the shutter rests on the stops.

In the prototype, the sealing is created by an elastic refractory material, which is laid around the perimeter of the damper, and in the proposed embodiment, the connection of the milled surfaces of the damper and the cooled box through which running water flows to cool it is used.

The disadvantages of the prototype are that:

- the design is complex;

- the furnace seal does not close the metal structure of the valve and the metal frame of the furnace window from the action of hot gases, therefore, the gases in the furnace contact and heat the metal frame of the furnace window and the metal frame of the valve, causing warpage and, as a consequence, leaks between them;

- due to the resulting leaks there will be significant heat loss;

- there is no heat-insulating layer in the damper, so the losses will be greater than if it were;

- low operational reliability due to the large number of springs, seals, shutter flaps.

The objective of the invention is to simplify the design, increase the tightness of the window being closed, increase operational reliability, reduce heat loss of the furnace, increase the service life.

The technical result is an increase in the reliability of sealing the furnace, reducing heat loss, simplifying the design of the device, increasing operational reliability, increasing the service life.

This is achieved by the fact that in the device for raising and lowering the furnace shutter, comprising a drive connected to the shutter by means of a flexible connection, a water-cooled box and restrictive stops at the furnace window, on which the shutter rests, a protective screen. The drive is made electric in the form of a gear motor containing a double roller block and two single roller blocks connected by a flexible connection in the form of chains between each other and a counterweight, while the shafts of the double and single roller blocks are fixed in the grooves of the stove plates to allow the shutter to move along the water-cooled box and with the possibility of adjusting its position from the control panel, and a water-cooled box with a chain forms an angle of 1 ° with the vertical, the shutter contains a U-shaped box with internal ribs and a cover, made Oh of heat-resistant cast iron with ribs and T-shaped cavities lined with refractory ramming mass.

Introduction to the design of the damper, which is cooled by air, leads to less heat, lack of warping and "leashes". The absence of warpage and leash leads to reliable sealing and reduce heat loss of the furnace.

In addition, the damper is cast and has inside T-shaped cavities lined with a refractory ramming mass having high refractoriness and heat resistance.

The execution in the damper of T-shaped cavities lined with a refractory ramming mass protects most of the molded damper from the direct action of hot furnace gases. The damper does not warp, does not “lead”, cracks and leaks are not formed, therefore, the damper has a longer service life. The use of a refractory ramming mass in the design of the shutter allows for multiple repairs.

The composition of the refractory packing material is as follows: chamotte mortar МШ-39 ТУ 14-199-199-2000, technical lignosulfonate ТУ 13-0281036-89, ground clay powder ПГБ ТУ 1522-009-00190495-99, phosphon (aluminochromophosphate mixture) ТУ 2149- 150-10964029-01, water.

At the same time, the damper has cast ribs, which additionally give it rigidity and stability against warping and a “leash”. In the case of intensive operation of the damper (with three-shift operation of the furnace for more than a year) and the beginning of collapse, sprinkling of refractory packing material, it is necessary to fill a new refractory packing mass. In addition, to increase the tightness of the plane of the valve, having a T-shaped cavity, it is recommended to process on a milling machine, remove a layer of 2 mm. The damper can be used for 5-6 years.

The damper is cast from heat-resistant (heat resistance - the ability not to oxidize at high temperatures) cast iron grade CH 28 GOST 776-82. As a result of this, the damper is highly resistant to warping and has a long service life.

At the same time, the damper has a U-shaped cast box, which is made with ribs for better heat loss by the damper to the passing cooling air.

It is significant to note that in the proposed embodiment of the device, it is possible to adjust the position of the shutter relative to the furnace window. When the shutter moves up and down, it moves along a metal cooling box lined in a furnace box, which forms an angle of 1 ° with the vertical plane. The chains holding the flap form an angle of 1 ° with the vertical. The adjustment of the position of the shutter relative to the furnace window is carried out by moving the single and double blocks of the drive rollers along the grooves of the mounting plates of these drive roller blocks. Such a constructive solution significantly reduces heat loss. The adjustment of the position of the flap relative to the furnace window is made after each repair of the flap.

It is significant to note that the damper has an electric drive, different from the prototype, consisting of a motor - gearbox МЧ - 125-80-12,5-56-1-УЗ, a twin roller block, a counterweight, two single roller blocks and chains 1-11- 33. The proposed drive design is simple and reliable. The drive can be controlled by a working smelter of metal and alloys, a working smelter of metal from a control panel located near the furnace, as well as a driver of a multi-loader from a portable remote control. The use of an electric drive makes it possible to smoothly raise and lower the shutter, provides simplicity of the entire structure, high operational reliability and good tightness.

In addition, the proposed design of the device for raising and lowering the damper of the furnace does not contain a single spring, or ball joints, nor wings, nor seals between the leaves.

The absence of these elements in the device provides simplicity of design and high operational reliability. Introduction to the design of the device for raising and lowering the damper of the furnace of the above allows you to successfully solve the problem.

Figure 1 shows a diagram of a device for raising and lowering the damper of the furnace.

Figure 2 (top view) shows the invention, mounted on a gas bath furnace.

Figure 3 is a section aa (sketch).

Figure 4 is a view of B.

In Fig.5 - the proposed valve with a section GG.

Figure 6 - sections bb, dd, increase J.

In Fig.7 is a section ZZ.

On Fig - section II.

For clarity, figure 1 shows a diagram of a device for raising and lowering the damper of the furnace. The present invention consists of a shutter 1, which is molded from heat-resistant cast iron ЧХ 28 GOST 776-82 (Cr 25-30%). As a result, the damper is highly resistant to warping and has a long service life. The damper 1 is cooled by air, which is fed through the elastic inlet pipe 2, then through the connector 3 and the inlet pipe 4 it enters the U-shaped box, cast at the same time with the damper 5. To improve the cooling of the air damper 1, the U-shaped duct 5 has cast fins inside 6, which increase the heat transfer area. Passing along the cast fins 6 of the U-shaped duct 5, heated air enters the exhaust pipe 7, then through the connector 8 and the elastic pipe 9 into the burners of the furnace (not shown). Air cooling leads to less heating of the shutter 1, the absence of its warping and "leashes". The absence of warping and a “leash” leads to reliable sealing and reduction of heat loss. When forming the shutter 1 in the future tides 10 fit, as embedded elements, loops 11, with the help of which, in the future, the shutter is suspended from the drive chains 12. The molding of the shutter 1 is made with rods on furan resins, which gives T-shaped cavities in the cast after knocking out the mold and removing the rods. Next, the casting is milled in two planes and a refractory packing mass 13 is filled into the T-shaped cavities. Excess refractory packing mass is removed with a ruler. Refractory ramming mass has the following composition:

Fireclay mortar MSH-39 TU 14-199-199-2000 53,2 Technical lignosulfonate TU 13-0281036-89 5 Powdered ground clay ПГБ ТУ 1522-00-001045 1,2 Foscon (aluminochromophosphate mixture) - TU 214-150-10964029-01 3 Water 19.6

The content of the components is given by weight in%. The refractory packing mass is then calcined at a temperature of 250-300 ° C for 5-6 hours. The execution in the damper of T-shaped cavities lined with a refractory ramming mass protects most of the molded damper from the direct action of hot furnace gases. Damper 1 does not warp, does not “lead”, cracks and leaks are not formed. It should also be noted that the shutter 1 has cast ribs 14, which additionally give it rigidity and stability against warping and “leash”. According to experimental data, during the operation of such a damper as part of a 12-ton gas bath of a reflective type furnace, collapse and sprinkling of the refractory stuffed mass began to occur within 12.5 months. The design of the valve allows you to extend its service life. It is necessary to do as follows. Remove the shutter, remove the crumbled refractory packing material from the T-grooves, to improve the tightness, remove a 2 mm metal layer on the milling machine, apply a layer of phosphon to the old refractory packing mass and stuff the prepared new refractory packing mass on this layer. Remove excess mixture, calcine the refractory packing material at a temperature of 250-300 ° C for 5-6 hours, weld the loops 11 to the drive chains 12 and adjust the position of the shutter 1 relative to the furnace window 15. Damper 1 can thus be repaired 5-6 times, therefore, the life of the damper is 5-6 years. This is a very important factor in the operation of the drive. The use of refractory ramming mass of the above composition and the large wall thickness of the shutter 1 can dramatically increase its service life.

It should be noted that the U-shaped box 5 is sealed because after casting the shutter 1 and its milling, a U-shaped cover of the box 16 is made. The U-shaped cover of the box 16 is welded around the perimeter to the U-shaped box 5. When the shutter 1 moves up -down it moves along the metal cooling water lined in the furnace box (box of the furnace window) 17 opening and closing the window 15 of the furnace. The plane of the box lined in the furnace (the box of the furnace window) 17 protruding from the furnace wall 18 forms an angle of 1 ° with the vertical plane. The drive circuits 12 holding the shutter 1 form an angle of 1 ° with the vertical. In the raised position, the shutter 1 is located opposite the protective screen 19. In the threshold 20 (window sill) of the furnace, which is supported by channels and jibs 21, there are four stops 22, on which the shutter 1 rests, being in the lower (closed) position. The upper plane of the four stops 22 has an angle of inclination towards the furnace equal to the angle of inclination of the lower ribs of the U-shaped duct 5. In the lower (closed) position, the shutter 1 rests on four stops 22 and due to the inclination of the stops, the slope of the chains 12, the slope of the metal cooled by water box 17, it fits snugly to box 17 (box window furnace). Practice has shown that the above conditions are optimal for smoothly raising and lowering the shutter 1 and sealing the furnace.

The fit is tight, since the shutter 1 and box 17 (box of the furnace window) are machined. The threshold 20 of the furnace is framed by metal sheets 23.

The drive of the device for raising and lowering the furnace shutter is electric. It contains: motor gearbox МЧ-125-80-12,5-56-1-УЗ, dual roller block, counterweight, two single roller blocks and chains 1-11-33. Figure 2, 3, 4 shows the installation on a gas bath of a 12-ton furnace of the proposed device for raising and lowering the furnace shutter. The gear motor 24 is mounted with bolts and nuts on a steel plate, which is welded to the longitudinal beams of the furnace, made of channel No. 20, laid on the rib. Rotation from the gear motor 24 is transmitted to the shaft with rollers 25 mounted on it, which are fixed with a key. The chains 12 are thrown onto the rollers 25, and the left ends (with respect to the double roller block) of the chains (at the left flap of FIG. 4) are connected via an earring 26 with a counterweight 27. The rollers 25 rotate in the sliding bearings 28. The right end of one chain is thrown through a single the roller block 29 and is welded to the left hinge of the shutter 1. The right end of the other chain is thrown through a single roller block 29 and welded to the right loop of the shutter 1. The single block of the roller 29 consists of a shaft 30, two plain bearings 28 located in the bearing housings 31. The roller single block 29 mounted on the shaft spigot 32. Fixing the bearing housings 31 to the bars 33 carried by bolts 34 and nuts 35 and spring washers 36. A single roller unit 29 is attached to the plate (not shown) which is welded to the longitudinal beams of the furnace. After mounting the device for raising and lowering the damper of the furnace on the furnace, adjustment is made. Firstly, the weight of the shutter 1 must be balanced by the counterweight 27. Secondly, they achieve a tight fit of the shutter 1 to the water-cooled box 17. Thirdly, they achieve easy, smooth lifting and lowering of the shutter 1. The working metal and alloys smelter can control the drive , a worker pouring metal from a control panel located near the furnace, as well as a driver of a multi-loader with a portable remote control. The use of an electric drive allows the shutter to rise and fall smoothly, providing simplicity of the entire structure, high operational reliability and good tightness.

In addition, the proposed design of the device for raising and lowering the damper of the furnace does not contain a single spring, or ball joints, nor wings, nor seals between the leaves.

The absence of these elements in the device provides simplicity of design and high operational reliability.

A device for raising and lowering the furnace shutter operates as follows.

When turning on the drive of the shutter 1 by pressing the “Up” button on the control panel, the gear motor 24 is turned on and the shutter 1 rises and, as soon as it stands opposite the screen 19, by pressing the “Stop” button the drive is stopped. It should be noted that in the raised position of the shutter 1, the furnace window 15 is fully open. In order to lower the shutter 1, press the “Down” button on the control panel. The gear motor 24 has a reverse, therefore, after pressing the “Down” button, the reverse is turned on and the shutter 1 is lowered, closing the window 15 of the furnace.

At the end of the downward stroke, the shutter 1 is pressed against the box (box of the furnace window) 17 and resting on four stops 22.

Around the perimeter of the contact of the shutter 1 and the duct (duct box of the furnace) 17 provides reliable sealing.

The proposed device for raising and lowering the furnace shutter is simple in design, can achieve reliable sealing, increases operational reliability, reduces heat loss, and also increases the service life.

Claims (2)

1. Device for raising and lowering the furnace shutter, comprising a drive connected to the shutter by means of a flexible connection, a water-cooled box and limit stops at the furnace window, on which the shutter rests, a protective screen, characterized in that the drive is made electric in the form of a gear motor, containing a double roller block and two single roller blocks connected by a flexible connection in the form of chains between each other and a counterweight, while the shafts of the double and single roller blocks are fixed in the grooves of the stove plates, ensuring that they are moved I of water cooled duct damper and with the possibility of regulating its position with the remote control, and a water-cooled box chain forms with the vertical an angle of 1 °. 2. The device according to claim 1, characterized in that the damper comprises a U-shaped box with internal ribs and a lid, made of heat-resistant cast iron with ribs and T-cavities lined with a refractory ramming mass.

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