RU2502029C1 - Shuttle furnace - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: proposed furnace comprises lined body, two-floor heating system, transfer system, bins, pull-out means, extractors, supports and roll table without drive. Transfer system is composed of solid hearth composed of the frame consisting of tubes arranged across furnace axis and welded together by plates on both sides, said plates resting on fixed supports mounted in furnace lining parallel to frame tube axes and made of variable round profile steel. Note that bottom of steel sheet is mounted at said frame. Detachable retainers made of trapezoidal shape metal plates converging to zero in lengthwise direction are secured perpendicularly to said bottom surface. Transfer system tail part 1.5 time larger than that of its working part is divided into three equal parts by three plates secured at the frame and used for initial rock drying and as furnace gates in transfer system reciprocation by two rope extractors.

EFFECT: simplified design, higher reliability and longed life, fuel savings, higher efficiency and quality, lower costs.

2 cl, 9 dwg

Description

The invention relates to the building materials industry and can be used in the production of foam-glass and ceramic porous plates and products by the method of high-speed layer-by-layer, single-row firing with swelling of powdered masses from volcanic and other glasses and freshly formed blanks with a thickness of 20-30 mm from intumescent clays.

There are layered, single-row high-speed methods of firing (expansion) of foam-glass (patent No. 2198363, author certificate. No. 1231036) and ceramic plates (patent No. 2198363). For the manufacture of foam-glass plates, high-speed firing of powdered raw materials from amorphous-siliceous rocks (perlites, lithium pumice, tuffs, diatomites, etc.) is used in a continuous slot furnace (Auth. Certificate. No. 1231036 Bull. No. 18. 05/15/1986 ., Patent No. 2198362 Bull. No. 4. 02.10.2003), in which the transport system is made in the form of a train of metal pallets interconnected by locks made of transverse pipes welded together by mounting plates and coated with metal sheets. On each pallet, fixed end and removable limiters are mounted. The latter are made in the form of a cut off triangular box, consisting of plates: lateral rectangular and lower trapezoidal. Bunkers with feeders are mounted above the furnace, of which, with periodic movement of the transport system through slots made on the roof of the furnace, layers (monolayers) of the raw material charge 20–40 mm thick are poured onto the surface of the pallets. The number of layers determines the thickness of the resulting plates. At the end of the oven, from the pallets, the plates are transferred to the refrigerator.

The disadvantages of this furnace design are:

1. In a slot-hole kiln, the powder mass is fed to the surface of the pallets from the bunkers through transverse slots from a height of ~ 0.9 m. On the roof of the furnace (including in the slots), the temperature reaches 1050-1100 ° C, therefore, the gradual adhesion of the powder mass on the walls of the cracks. There is no control over the uniformity of the supply of layers of material on pallets, which determines the quality of the resulting plates.

2. The transport system, consisting of individual pallets, slides through the longitudinal pipes of the frame along the tubular fixed supports and thereby undergoes gradual attrition, which leads to a reduction in their service life.

3. Pallets at the end of each firing cycle are removed from the train by a transfer trolley with a lifting mechanism and returned to the top of the furnace along the bypass path, which greatly complicates the process. In this case, the pallets are cooled from 1000 to ~ 400 ° C and then heated back to 1000 ° C in the oven, thereby undergoing multiple heat exchanges. This leads to an excessive consumption of fuel for firing and speedy thermal deformation of the pallets.

4. Removable and non-removable stops complicate the design of pallets, increase the consumption of heat-resistant steel and occupy a certain part of the useful area of the transport system and thereby reduce the productivity of the furnace by 10-12%.

For the manufacture of porous ceramic plates from intumescent fusible clays, freshly formed billets (25-30 mm thick) are subjected to high-speed firing on metal grating pallets (Patent No. 2198363 Bull. No. 4. 02/10/2003). Pallets made of pipes are connected in a continuous row in the form of a train using locks and U-shaped brackets. The supporting elements along which the pallets slide are made by cooled pipes mounted in the masonry of the furnace. The main disadvantages of this furnace are similar to the disadvantages set forth in paragraphs 2, 3.

Chamber furnaces, widely used in metallurgy, are intended for heating large steel ingots before rolling. They are characterized by uniform heating of products by volume. The furnace has a lined cover, which is moved by a crane. Ingots with a tick-mounted crane are installed on the under and heated, then removed with the same crane (A.A. Shchukin - Industrial furnaces and gas facilities of plants, Energia, M., 1973, pp. 18-19). These furnaces cannot be used for the manufacture of porous plates, since the issues of supplying raw material to the furnace and removing the plates at its required performance are not resolved.

The purpose of the invention is to improve and simplify the transport system of the shuttle furnace, ensuring its reliability and durability when implementing industrial production of effective foam-glass and ceramic porous plates and products, fuel economy, increasing productivity and quality of products, reducing cost.

Figure 1 shows the shuttle furnace in plan, figure 2 is a longitudinal section, figure 3, 4 are transverse sections, figure 5-9 is a kinematic diagram of the operation of the furnace.

The shuttle furnace for high-speed layer-by-layer firing of foam-glass slabs consists (Figs. 1, 2, 3) of a lined body 1, a transport system 2, supports 3, a heating system 4, pull outs 5, an ejector 6, hoppers 7 and 8. One-piece transport system (bottom ), including the working and tail parts, consists of a frame 9 made of pipes 10 mounted transversely to the axis of the furnace and welded together on both sides by plates 11, with the help of which the hearth 2, leaning, slides along the fixed supports 12, translational motion. The supports 12, made of round steel with a variable profile (figure 3), are mounted in the masonry of the furnace perpendicular to the axis of the furnace and mounted on the furnace body. A bottom 13 of sheet steel or cast iron (5 mm thick) is mounted on the frame, on which limiters 14 are made transverse to the bottom axis, made of metal plates (20 mm thick) of trapezoidal shape, tapering to zero in the longitudinal direction. The length of the tail portion of the hearth, exceeding 1.5 times the length of the working part (Fig. 1, 2), is based on the roller table (without drive) 15 and is divided into three equal parts using three plates 16. When the reciprocating movement of the working part of the hearth outside the furnace, it slides along the roller table (without drive) 17, the expanded plates from the working part of the hearth are removed with the ejector 6, and the hearth is moved with two cable or other pulling devices 5 according to the kinematic scheme of the shuttle furnace (Fig. 5-9).

In the production of ceramic porous plates 18 by the method of single-row firing of clay billets 19 (figure 4), the bottom 13 and stoppers 14 are excluded from the working part of the hearth, and the distance between the axes of the pipes of the frame 10 is taken to be about 100 mm.

The furnace operates as follows (Fig.5-9). The furnace is heated to operating temperature (1050 ° C) and the working part of the hearth is moved to the right with the right pulling device 5 so that its left end is under the hopper 7. Then the left hearth pulling device moves to the left and at the same time the first layer of raw material charge is fed from the hopper 7 to the thickness 20-40 mm (pos.4), and then in the isothermal mode in the furnace at 900-950 ° C for 7-8 minutes it is swollen. According to the above scheme, a second layer is fed to the expanded first layer and expanded in the furnace for 7-8 minutes and porous plates with a thickness of about 100 mm are obtained (pos. 6, 7). Firing is carried out according to a two-tier system: below the working part of the hearth - 800-850 ° C, above the hearth, i.e. on the surface of the layer of material 900-1000 ° C. The total duration of 1 cycle is about 20 minutes. When moving the hearth to the left from the hopper 8, a layer of the original rock (for example, perlite) with a thickness of 50-60 mm fractions up to 10 mm is fed to its tail. During cyclic-translational motion of the hearth, its tail part with the rock is flared and after three firing cycles (within 1 hour), the rock is dried from 6-7 to 1%, which corresponds to the requirements of grinding the rocks in a ball mill. According to the kinematic scheme (Fig.6, 7) from the working surface of the hearth, the expanded plates are pushed with a pusher 6 (pos. 1, 2) onto a longitudinal drive roller table (not shown in the figures) and the refrigerator is moved. At the same time, 14 plates are expanded in the oven and sent to the refrigerator. Then the cycle repeats.

The productivity of the shuttle furnace with a length of the working part of the hearth of 5.7 m, a channel width of 1.1 m and a cycle time of 20 minutes is 8000 m ³ / year. The dimensions of the plates are 600 × 400 × 100 mm. When two parallel transport systems (hearths) are installed in the furnace, the productivity will double.

Replacing a slit continuous kiln with a transport system from individual pallets to a shuttle kiln with a solid transport system (bottom) ensures the production of foam-glass and ceramic porous plates by high-speed layered and single-row firing.

This is achieved by:

1. The design of the furnace is simplified: instead of several slots and hoppers with feeders mounted on the arch of the furnace to fill the layers of powder mass, one hopper is installed outside the furnace, which allows you to control the quality of the layers of powder mass and, accordingly, the obtained porous plates fed to the bottom surface.

2. The design of the transport system is simplified: replacing the pallet train with a solid hearth eliminates locks and fixed (end) stops, which at the same time increases the useful area of the working part of the hearth by 10-12% and, accordingly, the productivity of the furnace.

3. Eliminates the need to transfer pallets from the end to the beginning of the furnace with a transfer trolley with a lifting mechanism along a freewheel. This simplifies the process and reduces capital costs for the construction of the plant. At the same time, if the pallets are cooled from 1000 to 400 ° C during each cycle, i.e. 600 ° C, the whole hearth is cooled from 1000 to 850 ° C, which almost eliminates the thermal deformation of the transport system and reduces heat consumption for firing.

4. The use of plates on the frame at the same time as the mounting and supporting element on the fixed supports made of round steel of variable profile extends the life of the working part of the hearth (frame pipes are not subject to wear).

Claims (2)

1. Shuttle furnace for firing with expansion of foam-glass slabs by the method of high-speed layer-by-layer firing of powdered masses from volcanic and other glasses, containing a lined body, two-tier heating system, hopper, ejector, supports, transport system, characterized in that the transport system is made in the form of a solid hearth consisting of the working and tail parts of the frame, made of pipes mounted transversely to the axis of the furnace, welded together on both sides by plates resting on fixed supports made of cr mild steel of variable profile and mounted perpendicular to the axis of the furnace, while the bottom is mounted on a frame of sheet steel 5 mm thick, on the surface of which limiters are made perpendicular to the axis of the furnace, trapezoidal metal plates narrowing in the longitudinal direction, and the tail part of the bottom of the transport system , exceeding 1.5 times the length of the working part, is divided into three equal parts by three transverse plates mounted on the frame, with the possibility of using it for drying the source rock and in ETS gate furnace, for providing reciprocating hearth furnace is provided with two cable vytaskivatelyami. 2. The shuttle furnace according to claim 1, characterized in that for a high-speed single-row firing-expansion of blanks from intumescent clays, the transport system is configured to remove the bottom and stops from the working part, and the distance between the axes of the frame pipes is not more than 100 mm.

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