RU192260U1 - Vermiculite electric hearth furnace with swiveling platform - Google Patents

Abstract

The utility model relates to the field of building materials, namely to technological equipment for producing expanded vermiculite from vermiculite concentrates. An electric furnace with a rotary hearth platform for expanding vermiculite contains a frame, a drum dispenser, a hearth platform with a drive, a baking tray made of refractory material mounted on the platform, electric heaters, thermal covers and mounting heads for electric heaters mounted on thermal covers, while the platform is rotatable, includes a frame with a vertical cylinder and braces on it, a fixed girdle ring mounted on the braces, and a rotary part of beams connected between battle, with a movable girdle ring and a turntable that is connected to a hollow axis installed in the bearings of the cylinder and connected to the drive in the form of a gear motor, a stand is installed in the hollow axis on which the metering beam and thermal covers are supported, which are supported by a fixed girdle completely covering a single baking sheet formed by refractory bricks mounted on beams; the dispenser is mounted over a single pan on the frame elements, including the aforementioned beam, contains its own drive, has a drum with longitudinal slots, the cross section of which decreases towards the center of the turntable; electric heaters are held under thermal covers, fasteners and fastening heads fixed to thermal covers, a slot is made in one of the thermal covers, suction pipes are connected to it, connected by a product pipe to a precipitating hopper and an exhaust fan. Effect: improving the quality of expanded vermiculite. 7 ill.

Description

The utility model relates to the field of building materials, namely to technological equipment for producing expanded vermiculite from vermiculite concentrates.

Known electric furnace for firing vermiculite concentrates (RU No. 2351862, IPC F27B 9/00, published 04/10/2009), containing a dispenser of raw materials, baking sheets made of refractory material and installed relative to each other at an angle, equipped with electric heaters and covers with removable elements, and electric heaters are made in the form of tapes mounted on the rib and placed longitudinally under the covers on the surfaces of the baking sheets, so that the spaces between adjacent heaters form longitudinal chambers.

Common features with the claimed utility model are a raw material dispenser, a baking sheet made of refractory material and electric heaters.

The specified furnace has the following disadvantage. When the flow of vermiculite grains moves, they slip relative to the refractory surface and the surface of tape electric heaters, frictional forces arise, which lead to the abrasion of the grains, when the grains move, their numerous collisions occur, peeling of the surface layers, partial breakage, and as a result, the grains decrease in size, a large amount of vermiculite dust and scaly particles are formed. All this reduces the quality of expanded vermiculite: it becomes filled with dusty and scaly particles located between the main grains, which increases the bulk density of the finished product and reduces its total volume in the array.

Known electric furnace for firing bulk materials (RU No. 183578, IPC F27B 9/06, F27B 15/14, published 09/26/2018), containing a frame in which are placed baking sheets with frames and covers made of refractory material and installed at an angle to each other to a friend with the provision of pouring loose material during the firing process from one baking sheet to another, electric heaters in the form of ribbons, longitudinally located on the surface of the baking sheets under the covers, mounted on a rib and fixed by means of heads with parallel faces, plates coatings of electric heaters made of dielectric refractory material, installed on the surface of baking sheets under the covers and having ridges and grooves on the side surfaces, and refractory bricks located on the frames of the baking sheets, longitudinal grooves are made on the lower surface of the plates in which the mentioned electric heaters are placed.

 Common features with the claimed utility model are a frame, baking trays of refractory material, covers and electric heaters, fixed by means of heads with parallel faces.

The specified furnace has all the disadvantages of the above analog.

The prototype is an electric furnace with a vibrating hearth platform (RU No. 166554, IPC F27B 9/06, published 11/27/2016), comprising a frame, a drum dispenser, a baking sheet made of refractory material (heat-resistant steel), electric heaters, a vibrating hearth platform with an eccentric drive, coil and conical springs mounted on opposite sides of the platform, equipped with rollers placed in the frame guides, a baking sheet mounted on the platform, a thermal cover mounted on the frame articulated above the baking sheet with with the possibility of opening up to 180 °, fixing heads for electric heaters, mounted on one side of the thermal cover and blocks with heat-resistant steel grooves to hold electric heaters in tension, mounted on the other side of it, mounted on heat-resistant bushings of dielectric material, which through traverses and steel ropes are connected to vertically hanging loads, ropes are passed through other blocks having dielectric bushings mounted on a horizontal axis fixed to the a little toad.

Common features with the claimed utility model are a frame, a drum dispenser, a hearth driven platform, a baking tray made of refractory material mounted on a hearth, electric heaters, thermal covers and mounting heads for electric heaters mounted on thermal covers.

  The specified furnace has the following disadvantages. When vermiculite moves along a baking sheet of a vibrational hearth platform, due to its vibrations, multiple intumescent grains slip over its surface, and friction forces arise that lead to their abrasion. The movement of intumescent grains caused by vibrations of the hearth platform leads to numerous contact interactions between them, exfoliation of the surface layers, to partial breakdown of the grains, and to a decrease in their size. These factors reduce the quality of expanded vermiculite: it is filled with dusty and scaly particles located between the main grains, which increases the bulk density of the finished product, and its total volume in the array decreases.

 The technical result of the utility model is to improve the quality of expanded vermiculite.

The specified technical result is achieved in that the electric furnace with a rotary hearth platform for expanding vermiculite, containing a frame, a drum dispenser, a hearth platform with a drive, a baking sheet of refractory material mounted on a hearth platform, electric heaters, thermal covers and mounting heads for electric heaters, fixed on thermal covers according to a utility model, the hearth platform is rotatable, includes a frame in the form of a support part with a vertical cylinder and braces on , a fixed girdle ring fixed to the braces, and a rotary part of transverse, supporting and longitudinal beams interconnected with a movable girdle ring and a rotary circle, which is connected to a hollow axis mounted in bearings in a vertical cylinder and connected by a gear transmission with a drive in the form of a geared motor, a fixed stand is installed in the hollow axis, on which the metering beam and thermal covers rest, which additionally rely on the fixed girdle ring, completely covering the units the first pan formed by refractory bricks installed on the longitudinal beams; a drum dispenser is mounted above a single baking sheet on the frame elements, including the aforementioned batcher beam, contains its own drive with a gear motor and V-belt drive, has a drum with longitudinal slots of variable width and depth, the cross section of which decreases towards the center of the rotary hearth platform; electric heaters are held under thermal covers, fasteners and fastening heads mounted on thermal covers, a slot is made in one of the thermal covers located next to the metering beam, there are suction pipes installed above the surface of a single baking sheet and connected by a product line to a precipitating hopper equipped with an exhaust hood a fan.

Due to the fact that the hearth platform is rotatable, is connected by a gear drive with a drive in the form of a gear motor, it has a single pan from refractory bricks installed on the longitudinal beams of the platform, completely covered with thermal covers equipped with electric heaters held under thermal covers, mounts and fixing heads, an oven with a preheated single pan and electric heaters, when rotating the hearth platform, it provides the movement of vermiculite concentrate in heat the marketing field of electric heaters and swelling.

Drum dispenser, due to its installation above the surface of a single baking sheet on the frame elements, including the aforementioned beam of the dispenser, by means of its own drive with a gear motor and V-belt drive, provides vermiculite concentrate to the surface of a single baking sheet. Since the longitudinal slots of the dispenser drum have a variable width and depth with a cross-sectional area decreasing towards the center of rotation of the rotary hearth platform, a different number of vermiculite concentrate particles are laid on the surface of a single baking sheet, and the further away from the center of rotation of the rotary hearth platform , the greater the circumference and the more particles are laid on it so that the entire surface of a single pan when turning the hearth platform 270 ° is completely covered with capes of intumescent vermiculite concentrate. A 270 ° rotation occurs in 2.8 ... 3.4 s, which is ensured by adjusting the rotation speed of the rotary hearth platform due to its drive, and this time, depending on the size of the concentrate particles, is sufficient for vermiculite to completely swell. Since intumescent vermiculite lies on a single baking sheet and does not slip on the surface of refractory bricks, its grains do not wear out, do not break and do not exfoliate, but remain whole, which improves the quality of the final product.

Due to the fact that a slot is made in one of the thermocouples located next to the batcher beam, in which there are suction nozzles installed above the surface of a single baking sheet and connected by a product line to a precipitating hopper equipped with an exhaust fan, the expanded vermiculite is sucked in at the place where The swivel hearth platform completes its 270 ° rotation. Expanded vermiculite, lying on a single baking sheet of refractory bricks, approaches the mentioned pipes, in which due to the working exhaust fan there is a sufficient vacuum, and is sucked through the pipes and the product pipe connected to them into the precipitating hopper.

Distinctive features of the claimed utility model is that the hearth platform is rotatable, includes a frame in the form of a support part with a vertical cylinder and braces on it, a fixed girdle ring mounted on the braces, and a rotary part of transverse, supporting and longitudinal beams interconnected with a movable girdle ring and a turntable that is connected to a hollow axis mounted in bearings in a vertical cylinder and connected by a gear transmission with a drive in the form of a gear motor, a fixed stand is installed in the hollow axis, on which the dispenser beam and thermal covers rest, which additionally rely on the fixed encircling ring, completely covering the single pan formed by refractory bricks installed on the longitudinal beams; a drum dispenser is mounted above a single baking sheet on the frame elements, including the aforementioned batcher beam, contains its own drive with a gear motor and V-belt drive, has a drum with longitudinal slots of variable width and depth, the cross section of which decreases towards the center of the rotary hearth platform; electric heaters are held under thermal covers, fasteners and fastening heads mounted on thermal covers, a slot is made in one of the thermal covers located next to the metering beam, there are suction pipes installed above the surface of a single baking sheet and connected by a product line to a precipitating hopper equipped with an exhaust hood a fan.

The presence of distinctive features allows us to conclude that the claimed utility model meets the patentability condition of “novelty”.

In FIG. 1 shows an electric furnace with a rotary hearth platform for expanding vermiculite together with a hopper-precipitator and an exhaust fan (thermal covers are conventionally not shown).

In FIG. 2 shows the rotary part of the frame of an electric furnace with a rotary hearth platform for expanding vermiculite (bottom view).

In FIG. 3 shows an electric furnace with a rotary hearth platform for expanding vermiculite with thermal covers (top view).

In FIG. 4 shows an electric furnace with a rotary hearth platform (top view) with removed thermal covers.

In FIG. 5 shows cross sections A-A and B-B of a drum dispenser of vermiculite concentrate.

In FIG. 6 shows a thermal cover with electric heaters (bottom view of the heaters).

In FIG. 7 shows a fragment I in section (according to FIG. 6) and a unit for fixing electric heaters to the mounting heads.

An electric furnace with a rotary hearth platform for expanding vermiculite (hereinafter referred to as the furnace) comprises a frame, FIG. 1, including a supporting part 1 with a metal cylinder 2, a rotary part made of welded transverse beams 3, bearing beams 4, longitudinal beams 5, FIG. 2, the turntable 6 and the movable girdle ring 7, FIG. 1, 2 and 4. The cavities between the beams 3, 4 and 5 are filled with heat-insulating material 8, and the entire lower surface of the frame over the above beams, FIG. 2, is covered with an additional layer of heat-insulating material 9.

Elements of the furnace, indicated by the positions 3, 4, 5, 6 and 7, as well as 8 and 9, are a single unit forming a rotary hearth platform.

The refractory brick 10, laid on the longitudinal beams 5 through heat-insulating gaskets 11, is assembled from these piece elements - refractory bricks 10, a single pan of the rotary hearth platform.

On the metal cylinder 2, with the help of braces 12, another fixed ring-shaped ring 13 is fixed for installation of thermal covers 14, 15 and 16 on it, FIG. one.

The rotary hearth platform is equipped with a drive in the form of a gear motor 17 with a pinion gear 18 engaged with a driven gear, which is mounted on a hollow axis 19 mounted in bearings inside the cylinder 2 (bearings are not shown in the figures) and connected to the turntable 6 hearth platform. Inside the hollow axis 19, a stationary stand 20 is mounted on which the thermal covers 14, 15 and 16 are supported, as well as a horizontal beam 21, FIG. 1, 3 and 4.

Thus, the elements of the furnace 13 and 20 serve to ensure that the thermal covers 14, 15 and 16 rest on them, and being located above a single baking sheet of the rotary hearth platform, completely cover it. In addition, the element 20 also serves to support the horizontal beam 21 on it.

Drum dispenser of vermiculite concentrate, installed with a gap relative to the surface of a single baking sheet on the rack 22, beams 21 and 23 and the rack 24, contains a drive motor gear 25 and a V-belt drive 26 (Fig. 1, 3 and 4). The dispenser drum 27 has slots 28 of variable width and depth longitudinal to its axis, while the sectional area of the slots 28 decreases from the right side of the drum 27 to its left side (see sections A-A and BB, Fig. 5). The hopper 29 of the drum 27 of the dispenser serves to accumulate and maintain an approximately constant level of vermiculite concentrate in it.

One of the thermal covers 14, 15 and 16, FIG. 3, namely the thermal cover 15, in FIG. 6 is shown below. All of these thermal covers are equipped with electric heaters 30, FIG. 6, mounting heads 31 and mounts for holding electric heaters 30 (mounting heads and mounts are shown conditionally).

In more detail, the fasteners (section I fragment) and the fastening head 31 (heater fastening unit) are shown in FIG. 7. Electric heaters 30 are held in suspension by clamps 32 made of strip nichrome, passed into refractory ceramic sleeves 33, kept from falling out by washers 34. The ends of 35 clamps 32 in the upper part are unbent, which ensures that the washers 34 and the electric heaters 30 themselves are held. The straightened ends 35 of the clamps 32 abut against the upper washers 36, which are mounted on asbestos washers 37 for electrical isolation of the washers 34 and 36 and the clamps 32. This connection of these parts forms a fastener echivayuschee retention electric heaters 30 under termokryshkami 14, 15 and 16 when they are mounted on the stationary ring fences 13 and stand 20.

In FIG. 7 also shows the heater fixing assembly, which comprises a mounting head 31 fixed, for example, to the thermal cover 15, using a threaded connection 38 and electrical insulating washers 39. And electric heaters 30 are fixed to the mounting head 31 using washers 40 and bolts 41. Such the fastening of the heaters 30 ensures reliable electrical contact with the fixing heads 31 connected to the electric circuit, as shown in FIG. 6.

In the thermal cover 16, FIG. 3, a slot is made opposite the beam 21, forming a place in which box-shaped suction nozzles 42 are placed, installed with a gap above the surface of a single pan, which are connected to the product line 43 entering the precipitating hopper 44, equipped with an exhaust fan 45, FIG. 1. Such an installation of the suction nozzles 42 ensures that the expanded vermiculite is sucked through the product line 43 into the precipitating hopper 44 using an exhaust fan 45 when the hearth platform is rotated 270 °.

An electric furnace with a rotary hearth platform for expanding vermiculite works as follows.

Electric heaters 30 are connected to the network, the geared motor 17 is started, and the rotary hearth starts to rotate at an angular speed n, as shown in FIG. 4. So the oven is heated for 20 ... 30 minutes. In this case, due to the thermal radiation of electric heaters 30 (they themselves are heated in 10 ... 15 sec to 730 ... 750 ° C) located under the thermal covers 14, 15 and 16, refractory bricks 10 are heated, forming a single pan. Thanks to the heat-insulating gaskets 11, placed under the refractory bricks 10 and the heat-insulating material 8 and 9, the loss of thermal energy through the lower part of the rotary hearth platform is minimized. In this case, the temperature on the surface of refractory bricks 10 gradually increases to 350 ... 450 ° C, which is maintained even further during the expansion of vermiculite, due to the fact that not all thermal radiation from electric heaters 30 is absorbed by vermiculite; part of it reaches the surface of the refractory bricks 10.

After warming up, the drum dispenser is launched, the rotation speed of the drum 27 of which is adjusted, for example, using a frequency controller (not shown in the figures) to a strictly defined frequency n ₁ . Since the longitudinal slots 28 on the drum 27 have a variable width and depth with a cross-sectional area decreasing towards the center of rotation (see sections A-A and B-B in Fig. 5), then for one full revolution of the drum 27 along each radius on the surface of a single pan fits a different number of particles of vermiculite concentrate. The farther from the center of rotation of the turntable, the greater the circumference and the more particles must fit on it. With the correct selection of the rotation speed n ₁ and the correct manufacture of slots 28 on the drum 27, the laying of particles of vermiculite concentrate will occur in a single layer over the entire surface of a single pan with small gaps between them, such that in the process of expansion of vermiculite, between its intumescent grains small gaps remained, due to which part of the thermal radiation of electric heaters 30 would reach the surface of refractory bricks 10 to maintain the temperature of a single pan 350 ... 450 ° C. The provision of such a mode of expansion is achieved by setting the frequency n ₁ rotation of the drum 27.

 A complete rotation of the hearth platform by 270 ° should take place over a period of 2.8 ... 3.4 s, depending on the particle size of the concentrate. This time, as a rule, is enough for vermiculite to completely swell.

 Since intumescent vermiculite simply lies on a single baking sheet, rotating together with a rotary hearth platform, and does not have a relative slip on the surface of refractory bricks 10, during the temperature exposure and expansion, its grains do not wear out, do not break and do not exfoliate, but remain whole, which improves the quality of the final product.

At this point, expanded vermiculite lying on a single baking sheet of refractory bricks 10 approaches the nozzles 42, in which due to the working (and correctly selected) exhaust fan 45 there is a sufficient vacuum, and it is sucked through the nozzles and the product pipe 43 connected to them silo 44 where it falls into it.

This achieves the technical result of a utility model - improving the quality of expanded vermiculite.

Claims (1)

An electric furnace for expanding vermiculite containing a frame, a drum dispenser, a hearth platform with a drive, a baking tray made of refractory material mounted on a hearth platform, electric heaters, thermal covers and mounting heads for electric heaters mounted on thermal covers, characterized in that the hearth platform is rotatable and includes a frame in the form of a supporting part with a vertical cylinder and braces on it, a stationary girdle ring mounted on the braces, and a rotary part, one of the transverse, supporting and longitudinal beams welded together, with a movable girdle ring and a rotary circle, which is connected to a hollow axis mounted in bearings in a vertical cylinder and connected by a gear transmission with a drive in the form of a gear motor, and installed in the hollow axis a stationary stand, on which the drum batcher beam and thermal covers are supported, which are additionally supported on a fixed shingles ring and completely cover a single pan formed by the floor beams are refractory bricks, while the drum batcher, having a drive with a gear motor and V-belt drive, is mounted above a single baking sheet on the racks and on the beam of the drum batcher, and contains a drum with longitudinal slots of variable width and depth, made with decreasing cross-section in the direction to the center of the rotary hearth platform, while the electric heaters are held under the thermal covers by mountings and mounting heads mounted on the thermal covers, one of the thermal covers being k, situated adjacent to said drum beam dispenser and is formed with a slot which can accommodate therein the suction nozzles, which are installed above the surface of a single pan to be connected to the production pipe for connecting the hopper-precipitant with an exhaust fan.

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