RU196899U1 - Vermiculite Electric Roasting Furnace - 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 vermiculite roasting furnace containing baking sheets made of refractory material and installed at an angle of 45 ° to the horizon with the possibility of pouring vermiculite from one to the other, baking sheets made of ceramic-vermiculite plates with a metal edge, heaters, earrings and mounting heads, mounted on the lids, the lower baking sheet is connected to a non-electrified module with slit-like heat chambers and slit-like channels, through which vermiculite moves over and over, tion of swelling; in each baking sheet there is only one heater made of nichrome wire in the form of a zigzag coil with two ends connected to two mounting heads mounted on the edges of the lid, and the earrings are made in the form of flat hooks in the upper part for fixing on the lid and round hooks with locks with which they hold the heater under the entire surface of the lid. Effect: increase the reliability of the furnace. 4 ill.

Description

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

A known electric furnace for roasting vermiculite concentrates (RU No. 2351862, IPC F27B 9/00, published April 10, 2009), containing baking sheets of refractory material, mounted to each other at an angle that ensures that vermiculite is poured out from one to the other, equipped with electric nichrome heaters located on the surfaces of the baking sheets, characterized in that the baking sheets are provided with covers with removable elements with protrusions forming a ribbed surface of the covers, and the electric heaters are made in the form ent, mounted on the edge and placed under lids on the surface of baking them longitudinally so that the space between adjacent heaters form longitudinal chambers.

Common features with the claimed utility model are a baking sheet made of refractory material, an electric heater placed under the lid, and a lid.

This oven has two drawbacks: firstly, a large number of individual U-shaped tape heaters elongated along the baking sheet, and secondly, twice the number of their electrical connections in a serial electric circuit. So with a baking sheet width of 700 mm, if the distance between the tapes of one heater and the tapes of adjacent heaters is, for example, 35 mm, then the U-shaped heaters themselves will already have ten pieces and each has two ends for their electrical connection in series, for example, with mounting heads ( eleven pieces). Thus, there are only twenty electrical connections on only one baking sheet, and if there are three baking sheets, then only sixty connections. This complex system of connecting electric heaters into a serial circuit on each baking sheet per se significantly complicates the design of the furnace and significantly reduces its reliability, since in each of these electrical connections the quality of the nichrome electrical contact with the mounting heads may be impaired, which will lead to overheating of the contact zone and burnout of the heater in this zone, which has repeatedly happened during the production of expanded vermiculite on such furnaces.

Also known is an electric furnace for firing vermiculite (RU No. 179055, IPC F27B 9/00, published 04/25/2018), containing baking sheets with covers made of refractory material and installed in relation to each other at an angle that ensures that vermiculite is poured out during firing with one on top of the other, and electric heaters placed under the baking sheets of the baking sheet longitudinally above the surface of the baking sheet with a gap, mounted on heads with parallel faces to ensure their parallel installation and made with consoles suspended and in the lower part of the baking sheets on the rotary earrings fixed through ceramic electrically insulating bushings pivotally on the rods mounted on the covers of the baking sheets, the earrings are made in the form of L-shaped levers, some of whose shoulders hold the console of the electric heaters, and the others are equipped with weights that provide tension to the electric heaters and the constancy of said clearance.

Common features with the claimed utility model are trays and covers installed at an angle and made of refractory material, electric heaters placed under the covers and forming a gap relative to the refractory surface of the tray, earrings and heads for fixing the heaters on one side.

The specified oven has the same two drawbacks: a large number of individual electric heaters (in this case, circular cross section) elongated along the baking sheet and, secondly, twice the number of their electrical connections in a serial electrical circuit using mounting heads. If you take the same baking sheet width of 700 mm with a distance between the heaters of 35 mm, then the heaters themselves will need ten pieces and each of them has two ends for their serial electrical connection to the circuit. We have the same twenty electrical connections on only one baking sheet. Such a system of connecting each electric heater with the neighboring ones in a series circuit greatly complicates the design of the furnace and significantly reduces its reliability, since reliable electrical contact of nichrome with mounting heads may not be ensured in each of these electrical connections, which will lead to overheating of the contact zone and burnout of the heater in this zone, which has repeatedly happened in the production of expanded vermiculite in furnaces with wire (round section) heaters, even when using electric wire high temperature contact lubricants.

As a prototype, an electric vermiculite roasting furnace (RU No. 161281, IPC F27B 15/00, published on 04/20/2016) was adopted, containing baking sheets with lids, while the baking sheets are made of refractory material and are installed in relation to each other at an angle that ensures pouring raw materials during the firing process from one to the other, and electric heaters placed longitudinally under the baking sheets and fixed on heads with parallel faces to ensure their parallel installation, electric heaters made with consoles and are located above the surface of the pan with a gap, while the consoles of electric heaters are suspended in the lower part of the pan on the rotary earrings fixed through ceramic electrically insulating sleeves pivotally on the rods mounted on the covers of the pan.

Common signs with the claimed utility model are trays and covers installed at an angle and made of refractory material, electric heaters (hereinafter referred to as heaters) placed longitudinally under the covers with a gap relative to the refractory surface of the tray, earrings and heads for fixing the heaters on one side.

The specified furnace has exactly the same disadvantages.

The inventive utility model is aimed at improving the reliability of an electric furnace for firing vermiculite through the use of a single heater with two mounting heads.

The technical result of the utility model is to increase the reliability of the furnace.

The specified technical result is achieved in that the electric furnace for burning vermiculite contains baking sheets made of refractory material and installed at an angle of 45 ° to the horizon with the possibility of pouring vermiculite from one to another and providing the movement of intumescent particles of vermiculite on the refractory surfaces of baking sheets, baking sheets made from ceramo-vermiculite plates with a fringing from a metal corner, heaters, earrings and mounting heads mounted on the covers, lower baking sheet of the oven connected to a non-electrified module with slit-shaped heat chambers and slit-like channels, through which vermiculite moves for final expansion, while in each pan there is only one heater made of nichrome wire (with a circular cross section) in the form of a zigzag coil with two ends, connected to two mounting heads mounted on the edges of the cover, and the earrings are made in the form of flat hooks in the upper part for fixing on the cover and round hooks with locks, which nor hold the heater under the entire surface of the lid.

Between the zigzag heater and the refractory base of the pan there is a gap in which vermiculite moves, being exposed to high-temperature thermal radiation and swells.

Due to the fact that the lower baking sheet of the oven is connected with a non-electrified module with a “broken” case, in which thermally insulated slit-like heat chambers are made, through which hot air is pumped with a fan, practically eliminating heat losses from the slit-like channels, through which vermiculite moves and is scattered over finally swells due to heat transfer between small, warmer vermiculite grains with larger grains.

Due to the fact that each heater in its pan is made in the form of a zigzag coil in the entire width of the pan and has only two ends for electrical connection with two mounting heads mounted on the edges of the lid (there are twenty in the prototype of such joints), the design of the furnace is greatly simplified and almost completely eliminates the possibility (but not 100%) of overheating of the contact zone and burnout of the heater in this zone.

Due to the fact that the earrings in the lower part have rounded hooks with locks to hold the heater under the entire surface of the baking sheet, it is possible to quickly replace the heater in case of burnout (although this is unlikely) or when the resource is used up (3500 ... 4000 hours).

Distinctive features of the claimed utility model from the prototype is that only one heater is placed in each baking sheet, the heater is made in the form of a zigzag coil with two ends for electrical connection with two mounting heads installed along the edges of the lid, and the earrings are made in the form of flat hooks in the upper parts and rounded hooks in the lower part with special locks to hold the heater under the entire surface of the lid.

The presence of distinctive features proves the compliance of the claimed utility model with the condition of patentability “novelty”.

In FIG. 1 shows an electric vermiculite kiln.

In FIG. 2 shows a longitudinal section through a baking sheet.

In FIG. 3 shows a view A of a baking sheet heater.

In FIG. 4 shows an earring for attaching a heater.

An electric vermiculite kiln, FIG. 1, 2, 3 and 4, contains a drum dispenser of vermiculite concentrate (not shown in Fig. 1) with a drain tray 1, along which the concentrate is poured onto the upper part of the upper pan 3. Inside the furnace body 4 at an angle of 45 ° with the possibility of regulation within 40 ... 50 °, the upper 3 and lower 5 trays are installed in series, including heaters 6 and lids 7, made of ceramic-vermiculite plates with a fringing of a metal corner. Between the upper 3 and lower 5 baking sheets on the upper baking sheet 3, a sheet metal bump 8 is installed at the bottom, and the lower baking sheet 5 is paired with an additional non-electrified module 9 with a broken case in which are thermally insulated, including outside (in Fig. 1, the outer insulation not shown), slit-shaped thermal chambers 10 with a width equal to the width of the baking sheets 3 and 5 of the furnace. These chambers 10 are designed to pump hot air through them, so they are connected by pipelines 11 through the suction pumps 12 to the upper parts of the upper 3 and lower 5 baking sheets, where hot air comes out due to temperature traction. In the depth of the additional module 9, slotted channels 13 are made.

Ceramo-vermiculite plates of covers 7 of baking sheets 3 and 5 are edged by a welded metal corner 14, FIG. 2, connected to the plates 15, inserted into the grooves of keramovermulikulite plates and holding them. A wire heater 6 is placed and secured under the ceramic-vermiculite plate of the cover 7 of the baking sheet with rounded hooks 16 of the earrings and on the fastening heads 17 mounted on the covers 7. The earrings themselves are held in the holes 18 of the ceramic-mermiculite plate of the cover 7 due to the flat hooks 19, FIG. 2, 3 and 4. To close the rounded hooks 16 of the earrings, a special lock 20 is used, FIG. 4, made, like earrings from thin ribbon nichrome, 7 ... 8 mm wide and 1 mm thick.

The fixing heads 17 located at the edges of the cover 7 provide electrical contact between themselves and the two ends of the heater 6 due to the threaded connection 21 with the washer 22, FIG. 2 and 3, and supply electric cables (not shown in the figures).

Between the heaters 6 and the refractory bases of the baking sheets 3 and 5 there is a gap a, FIG. 2.

An electric furnace for burning vermiculite works as follows. Vermiculite concentrate through tray 1 enters the upper part of the refractory surface of the upper baking sheet 3. The ovens 4 installed in the body 4 at an angle of 40 ... 50 ° to the baking sheet horizons 3 and 5 provide the particles of vermiculite concentrate to move, and subsequently vermiculite grains begin to swell along the refractory surfaces of the baking sheets under the action of gravity in the thermal field of wire heaters 6 emitting energy in the thermal part of the spectrum, fixed by rounded hooks 16 of the earrings under the covers 7. Mounting heads 17 are installed the cover 7 only provide electrical contact with each other and the two ends of the heater 6 in each pan.

In the zone of pouring vermiculite from the upper 3 to the lower 5 baking sheets between the upper 3 and lower 5 baking sheets on the upper baking sheet 5, a chimney 8 is installed to damp the speed of the vermiculite flow, which causes the vermiculite grains to stop and accelerate again on the lower baking sheet 5, which increases the total firing time of vermiculite .

Since the lower pan 5 is paired with an additional non-electrified module 9 having a broken body, partially not fully expanded vermiculite enters the additional module 9 (for example, it should have a bulk density at the furnace exit of 96 kg / m³, but enters the additional module 9 with a density of 108 kg / m³, that is, with the missing difference in densities 12 kg / m³) Inside the module 9, through the thermally insulated slit-like heat chambers 10 with a width equal to the width of the baking sheets 3 and 5 of the furnace, hot air is pumped with a fan (not shown in Fig.), Eliminating almost completely the heat loss from the slit-like channels 13, through which it flows vermiculite and finally swells due to heat exchange between small, warmer vermiculite grains with more than almost swollen large grains. The experimentally proven effect of the additional module is described in [A.I. Nizhny Novgorod, A.V. Zvezdin. Investigation of the physical model of an electric furnace for firing vermiculite with a "zero" module. New Refractories Magazine, No. 6, Moscow, 2016, p. 13-18]. Therefore these missing 12 kg / m³ (and even more) makes up for the additional module 9, which partially saves the energy consumed by the furnace.

The fan through the pipelines in the lower part of the module 9 draws out hot air (“to the hood”, Fig. 1) from the pipelines 11 through the suction devices 12 from the space of the vermiculite spillage zones, where due to the temperature traction hot air comes out of the baking sheets.

Between the heaters 6 and the refractory bases of the baking sheets 3 or 5, there is a gap a, in which the intumescent vermiculite moves, being fired.

Due to the fact that the heater 6, FIG. 3, each baking sheet is made in the form of a zigzag coil and has only two ends for electrical connection with mounting voices 17 installed on the edges of the lid 7, each baking sheet has only two electrical connections (against twenty, as in the prototype), the design of the baking sheets is greatly simplified 3 and 5 and the furnace as a whole.

And due to the fact that the earrings are made in the form of flat hooks 19 in the upper part and rounded hooks 16 with special locks 20 in the lower part, it is possible to quickly replace the heater 6 in each of the baking sheets when they work out their life or when they burn out, which is in this design although it is possible, but due to the fact that the heater hangs over the moving vermiculite and does not come into contact with it, it is unlikely.

Both of these features of the utility model provide increased reliability of the furnace and simplify its design, reducing the cost of the furnace.

This achieves the technical result of the utility model - increasing the reliability of the furnace for burning vermiculite.

Claims (1)

An electric vermiculite roasting furnace containing baking sheets made of refractory material and installed at an angle of 45 ° to the horizon with the possibility of pouring vermiculite from one to the other, baking sheets made of ceramic-vermiculite plates with a metal edge, heaters, earrings and mounting heads, mounted on the lids for securing the heaters, characterized in that it is equipped with a non-electrified module designed to pour vermiculite on it until its final knitting, made with a broken case, in which there are slit-like thermal chambers with slit-like channels, made with a width equal to the width of the baking sheets, connected by pipelines with the upper parts of the upper and lower baking sheets for pumping hot air leaving the said baking sheets through the chambers, each a single heater is placed on the baking sheet, made of wire nichrome in the form of a zigzag coil with two ends connected to two mounting heads mounted at the edges of the lid, and with rgi are in the form of flat hooks in the upper part for fixing on the cover and locks with rounded hooks, which they hold the heater under the entire cap surface.

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