JPH03181788A - Device for drying or baking ceramic product - Google Patents

Abstract

PURPOSE: To prevent considerable amounts of pressure and calorie from being lost, by providing a groove filled up with a liquid on the floor of a tunnel kiln and a circulating track for truck on the bottom of the groove, and an sealing a shaft with immersed fluid by dipping the lower portion of the downward skirt of each truck in a liquid and, when the door of the tunnel kiln is opened particularly, absolutely preventing the circulation of a high- temperature gas. CONSTITUTION: Rails 2 are laid on the bottom of a groove 1 filled up with a liquid, such as water, etc., and a truck 4 carrying a product 5 to be dried or baked circulates in a tunnel kiln 6 and is provided with a means which circulates a high-temperature gas in the kiln 6. The platform of each truck 4 is provided with a skirt along its full circumference and the inner end of the skirt 7 is dipped in the liquid. A space 8 under the platform of the truck 4 and inside the skirt 7 is isolated from the internal portion of the kiln 6. When the truck 4 circulates, the front and rear walls of the skirt 7 come into contact with each other and the ends of the walls are connected to each other, resulting in the formation of two nearly continuous walls. Therefore, the space under the truck 4 is tightly closed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the technology of tunnel furnaces used for drying and/or firing terracotta products such as tiles, bricks, floor coverings, etc.

These products start with clay or a mixture of clays, are formed by molding or extrusion, are dried, and then fired at high temperatures. To automate production, elongated ovens are used for drying and baking. Inside this oven, trolleys carrying products to be dried or fired circulate. Such a furnace is called a tunnel furnace. Tunnel furnaces are equipped with doors at both ends so that carts can be moved in and out without significantly disturbing the internal temperature conditions and, in particular, the pressure inside the furnace, which determines the circulation of hot gases within the furnace. has been done.

However, every time the trolley is moved in and out, high-temperature gas under pressure flows out from under the trolley, so it is certain that a considerable amount of pressure and calories will be lost! has been done.

The present invention aims to solve this problem.

- The apparatus for drying and/or firing terracotta products according to the invention is of the tunnel furnace type with a tunnel, within which a track is installed, on which drying or firing is to be carried out. The trolleys carrying the products circulate, the floor of the tunnel furnace is protected from the liquid-filled groove, the circulation track of the trolleys is installed at the bottom of the tunnel, and the platform of each trolley has a downward skirt along its entire circumference. are fitted, the lower part of the skirt being immersed in the liquid, the vertical walls of each skirt forming a liquid injection shaft seal with the liquid in the groove to enable the carriage to circulate in the tunnel furnace, and in particular The tunnel door is characterized by completely preventing the circulation of hot gas from under the bogie when the tunnel door opens.

BRIEF DESCRIPTION OF THE DRAWINGS By way of non-limiting example, embodiments of the invention will be presented below with reference to the accompanying drawings, so that the invention may be more easily understood.

With reference to FIG. 1, it can be seen that the wheels 2 of a truck 4 are arranged on rails 2 in accordance with the invention. The rail 2 is placed at the bottom of the groove 1, which groove I is filled with a liquid, for example water. A trolley 4 carrying a product 5 to be dried or baked circulates inside a tunnel 6, and the tunnel 6 is equipped with means (not shown) for circulating hot gas inside the tunnel 6.

Each platform of the truck 4 is provided with a skirt 7 along its entire circumference. The inner end of the skirt 7 is immersed in the liquid. The space 8 located inside the skirt 7 and below the platform 4 is completely isolated from the rest of the furnace interior. Negative pressure/pump effect
In order to prevent cloche, it is desirable to provide at least one vent hole in the upper part of one wall of the skirt 7, so that the pressure in the space 8 is equal to the pressure occupying the inside of the tunnel.

In such a furnace, the cart 4 is circulated by pushing the cart that entered last (see Fig. 8). As a result, the front and rear walls of the skirt 7 of the cart 4 are all in contact, and their ends are connected, making them almost Forms two continuous walls. Therefore, the entire space under the truck is sealed, and no high-temperature gas is circulated there.

Such an arrangement makes it possible to circulate the hot gases within the furnace more effectively and thus to considerably improve the thermal efficiency.

FIG. 3 shows one variant, in which the same elements as shown in FIGS. 1 and 2 have been given the same reference numerals.

In this embodiment, a rail 2 is installed at the bottom of the groove 1. The groove 1 emerges from a metal caisson 10 and is supported on both sides by two low walls 9 and at the bottom by a longitudinal member 11. These longitudinal members are arranged, for example, on a concrete slab 12 at floor level S, as shown. In such a case, the liquid tank 1 is located higher than the floor level.

Although this reduces bulk, breakage or leakage of the caisson 10 may cause flooding and cause significant damage.

In the illustrated embodiment, the platform of each trolley 4 is separated from a transport board 14 on which a heat-resistant material 513 is applied. Also, the scars 1-7 are in contact with the transport board 14.

If a l.Nenl furnace is used to carry out the firing operation, the product 5 is placed at a temperature of about 1,200°C and the layer 1
The upper part of the skirt located above 3 is about 500-600°
C, and the lower part has a much lower temperature, generally 10
Ensure that the temperature is maintained below 0°C. As a result, considerable thermal stresses occur within the skirt 7, particularly in the upper portion 7a.

In order to solve this problem, the skirt 7 is
Install as shown in the diagram.

First, each skirt is formed with modular elements 15 side by side, as shown in these figures. Module element 15
The cross section a is U-shaped with a wide mouth, and includes a flat bottom 15a, two oblique edges 15b, and two straight edges 15c that are perpendicular to the flat bottom. . Each module element is fixed by its two edges 15 to the platform or carrier board 14 of the trolley 4. In this way sufficient elasticity of the expandable modular element was achieved.

Second, as shown in FIG. 3-4
A slit 16 with twice the length is provided.

This slit 16 opens into a round orifice provided through the thin plate. Such a configuration makes it possible to prevent cracking of the upper edge of the U-shaped element when placed under high temperatures.

FIG. 4 shows a modification of the apparatus shown in FIGS. 1-3. A problem with the configurations shown in FIGS. 1 and 2 is that it is not easy to achieve concrete trenches that must be completely waterproof.

Therefore, a metal casing as shown in FIG. 3 was used.

However, the system of metal casing 10 shown in FIG. 3 can be installed in a concrete trench in the floor S. In this case, even if the metal casing is damaged, there is no risk of water intrusion.

However, tunnel furnaces currently in use have a length of 150 meters or more. Therefore, installation and maintenance of such casings is difficult.

Referring to FIG. 4, according to a third modification of the invention, a first concrete groove 20 is provided in a hole 21 provided in the floor S. This first concrete groove 20 is covered with a multi-layer waterproof sheet 23 made of a bondable waterproof rubber material.

In the waterproof area achieved in this way, the first and second
A second concrete: M24 is provided corresponding to the groove 1 shown in the figure. In this way, even if the second groove 24 has some holes, a completely waterproof groove can be achieved.

In such a tunnel furnace, it has been confirmed that the region A located above the platform of the carriage 4 and the region B located below it must be separated as much as possible inside the furnace (FIG. 4). In fact, region A has a very high temperature (
The temperature in region B should desirably be kept below 100°C, while the temperature in region B should desirably be kept below 100°C.

To achieve this separation, recesses 25 are provided in the two side walls 6a of the tunnel furnace 6 at the level of the platform of the carriage 4.
will be established. Correspondingly, each platform of the truck is provided with a protrusion 26 on both sides, shaped to fit into a recess 25. In this way, the protrusion 26 of each cart can be fitted into the recess 25 of the side wall of the furnace with a gap. Thereby, heating of the region B due to direct radiation of the region A can be prevented.

FIG. 7 very schematically represents a tunnel furnace of large dimensions. Inside the tunnel furnace, there are parts that are in contact with each other.
The next trolley 4 is passing. The circulation in the furnace shown takes place along arrow F from left to right. For this purpose, the furnace is equipped at the entrance with means for pushing the last cart entered, so that the entire series of carts can be pushed.

Although the groove 1 considerably improves the control of the thermal conditions in a tunnel furnace configured as described above, a number of problems remain at the entrance and exit of the furnace. In the case of a trench 1 located below the level of the factory floor S, means are needed to lower the carts one by one into the trench 1 at the entrance and to take them out at the exit. Then, during such operations, the interior of the furnace, especially area A
should be prevented from coming into contact with external pressure (as much as possible).

To solve these problems, transport means T are installed at both ends of the furnace. The transport means T serves to lower the cart located in the groove at the entrance, and to lift the cart that has come out to the height of the track provided on the floor S at the exit. Furthermore, a lock chamber 27 consisting of two guillotine doors 28 is also installed at the exit and entrance.

Figures 8 and 9 are perspective and side elevation views of such a door 28. Looking at Figure 9, each door has frame 3.
It can be seen that it is supported by 0. The height of this frame 30 is twice the height of the tunnel furnace. The base of this frame is located in the groove l. In this way, the ninth
When the moving part 31 of the door, shown in the figure in the open position and in the high position, moves to the low position (closed position), the base of the door is immersed in the liquid in the groove 1. In this way, complete tightness of the door base can be achieved.

[Brief explanation of drawings]

1 is a schematic partial cross-sectional view of a tunnel furnace with liquid-filled grooves according to the invention; FIG.
3 is a schematic diagram in partial longitudinal section of the furnace of FIG. 3; FIG. 3 is a schematic diagram in partial cross section of a first variant of the tunnel furnace according to claim 1; FIG. 7 is a schematic partial cross-sectional view of a second variant of the tunnel furnace according to item 1; FIGS. 5 and 6 are three views showing a variant of the cart skirt; FIG. , a schematic view showing a tunnel furnace with lock chambers at the inlet and outlet; FIGS. 8 and 9 are two drawings showing an embodiment of the lock chamber door shown in FIG. 8; FIG. (Main reference numbers) ■...Groove, 2゜3...Wheel, 4. 5...Product, 6. 7.Skirt, 8. 9..Small wall, 10. 11..Vertical member, 12゜13. Heat-resistant layer, 14. 15. Module element, 16. Slit, 17. 21. Hole, 22. 23. Waterproof sheet, 24. 25. Recess, 26. 27. Lock chamber, 28.・30...Frame/rail, ・Bogie, ・Tunnel furnace/space, ・Caisson, ・Concrete slab/transport board, ・Orifice, ・First groove, ・Second groove, ・Protrusion, ・Door, Agent Patent Attorney Hideaki Kuwahara (Volunteer) Procedures Toho Seishohei, F&2 January 25th

Claims (9)

[Claims] (1) A tunnel furnace-type ceramic product drying and/or firing facility equipped with a tunnel, in which a track is installed, and a trolley carrying the product to be dried or fired circulates on the track. , the floor of the tunnel furnace (6) is filled with liquid in the grooves (1, 24)
A circulation track (2) of a bogie (4) is installed at the bottom of the groove, and a downward skirt (7) is attached to the platform of each bogie (4) along its entire circumference. The lower part is immersed in the above liquid, and each skirt (7)
The vertical walls of the grooves (1, 24) together with the liquid in the grooves (1, 24) form a liquid injection shaft seal to allow the carriage to circulate inside the tunnel furnace (6), and at the same time prevent the bottom of the carriage, especially when the tunnel door is opened. A device characterized in that it prevents any circulation of high-temperature gas from. (2) The groove (1) is a concrete groove provided in the floor so that the height of the liquid is below the level of the floor "S". equipment. (3) The grooves are double, with a first concrete groove (20) provided in the floor and a multilayer waterproof sheet (23) made of an adhesive elastic material covering the surface of the first groove (20). ) and a second concrete groove (24) provided on the waterproof sheet. (4) The device according to claim 1, characterized in that said groove (1) is a metal casing provided on the floor or at the bottom of a concrete groove. (5) Each trolley is provided with a carrying board (14), on which a heat-resistant element (13) is installed, a skirt (7)
5. Device according to any one of claims 1 to 4, characterized in that the carrier board is mounted around the transport board. 6. Device according to claim 5, characterized in that said skirt (7) consists of U-shaped elements (15) juxtaposed to compensate for expansion effects. 7. Device according to claim 6, characterized in that the upper part of each U-shaped element (15) is provided with a slit (16) leading to a round orifice. (8) Each platform of the carriage (4) is provided with a protrusion (25) along its lateral edge, which protrusion (25) is provided on the corresponding wall (6a) of the tunnel furnace (6). It is characterized in that it fits with a correspondingly shaped recess with a gap, so that region B of the furnace located below the platform is not heated by direct radiation from region A located above the platform. Apparatus according to any one of claims 1 to 4. (9) The tunnel is provided at each end with compartments for placing each carriage in the groove (inlet) or for taking it out of the furnace (exit), and these compartments are further provided with two guillotine doors (28
) with a lock chamber (27), each guillotine door (
9. Device according to any one of claims 1 to 8, characterized in that 28) is supported by means (30) ensuring that the base of the door is immersed in liquid when it is closed. .