JPS63187092A - Tunnel kiln, variation of kiln pressure of which is prevented - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a tunnel kiln used for firing roof tiles and other ceramic products, which prevents fluctuations in furnace pressure when a cart is moved in and out.

(Prior technology) A trolley loaded with the materials to be fired is intermittently run inside a tunnel-shaped furnace body, which has an inlet for the materials to be fired at one end and an outlet for the materials at the other end, and preheats, bakes, and cools the materials. A tunnel kiln that allows each process to pass through is conventionally well known. In nine of these tunnel kilns, a pressure gradient is formed such that the pressure gradient is higher on the outlet side and lower on the carry-in port side. However, in this type of tunnel kiln, it is necessary to open the hearth door when loading and unloading the trolley, so gas inside the furnace flows out into the atmosphere each time, which has the disadvantage that the pressure inside the furnace temporarily drops. In order to solve this problem, as shown in Japanese Patent Publication No. 60-12552, preliminary chambers are formed at both ends of the furnace body, and on the loading side, the trolley is first put into this preliminary chamber, and then the preliminary chamber is After closing the outer door of the chamber, exhaust the air using a furnace pressure control device such as an exhaust fan until the internal pressure in the preliminary chamber becomes approximately equal to the furnace pressure at the tip of the furnace, and then open the inner door between it and the furnace body. On the unloading side, before putting the cart into the auxiliary chamber, the inner and outer doors between the auxiliary chamber and the furnace body are closed, and the internal pressure in the auxiliary chamber is lowered to the furnace using a pressurizing fan, etc. A tunnel kiln has been proposed in which fluctuations in the internal pressure of the furnace body are prevented by pressurizing the kiln until it becomes approximately equal to the furnace pressure at the inner rear end, then opening the outer door of the preliminary chamber and transporting the cart to the outside. However, such conventional tunnel kilns have the disadvantage that a special furnace pressure control device is required in the preliminary chamber in order to make the pressure in the preliminary chamber approximately equal to the pressure inside the furnace. Problems) The present invention solves the above-mentioned conventional problems, and eliminates fluctuations in the pressure inside the furnace not only when the outer door is opened but also when the inner door is opened. It was completed with the aim of creating a tunnel kiln that could prevent furnace pressure fluctuations without requiring a special furnace pressure control device.

(Means for Solving the Problems) The present invention forms a preliminary chamber with an inner door at the end of the furnace body of a tunnel kiln, and adjusts the furnace pressure in that part near the inside of the inner door of the furnace body. In addition, after closing the outer door of the auxiliary chamber, the inner door is slightly opened to gradually introduce the furnace gas into the auxiliary chamber, making the internal pressure of the auxiliary chamber approximately equal to the furnace pressure. It is characterized by being equipped with an opening degree control device.

(Embodiment) Next, the present invention will be explained in more detail with reference to an illustrated embodiment. In FIG. 1, (1) is a furnace body of a tunnel kiln, and one end on the left side in FIG. (2
), the other end on the right side is the exit (3), (4),
(5) are preliminary chambers formed at both ends of such a furnace body (11), and sand seals (6), (7) are provided at the top on the outside of each preliminary chamber (4), (5). Outside B (8), (9
) is provided so that it can be opened and closed freely. Also (10), (11
) are inner doors provided between each preliminary chamber (4), (5) and the end of the furnace body (11), but these inner doors (10), (
Door pocket-shaped covers (12) and (13) are provided on the outside of the furnace (11) to prevent the pressure inside the furnace from leaking to the outside even when the inner doors (10) and (11) are opened. There is.

(14) is a fan for adjusting the furnace internal pressure, which is provided near the inside of the IR (11) in the furnace body (1). This fan (1
4) is for raising the pressure inside the furnace near the outlet (3) above atmospheric pressure by suctioning outside air and blowing it into the furnace through the duct (15), but a control damper is installed in the duct (15). (16) is provided, which is opened and closed by a control motor (18) linked to a pressure detection unit (17) that measures the furnace internal pressure in this area, and the furnace near the outlet (3) is opened and closed. It plays the role of keeping the internal pressure constant. Although not shown, a fan is installed near the inside of the inner door 0Φ on the loading port (2) side of the furnace body (1) to suck gas in the furnace and release it into the atmosphere. It may also be possible to form a stable pressure gradient at 17i.
(10), (11) may be side-opening types, in which case there is a cover (12) on the side of the furnace body (11), (
13) will be formed. Furthermore, these inner doors (1
0), <11) is equipped with an opening control device (19).
), (20) are provided. Opening control device (19)
, (20) is the inner R (10
), (11) are fully opened, but also the inner doors (10), (11) are closed after the outer doors (8), (9) of the preliminary rooms (4), (5) are closed. It opens slightly and operates to gradually introduce the furnace internal pressure into the preliminary chambers (4) and (5). Such opening control devices (19), (2
The operation of step 0) will be explained in more detail below.

(Function) In this structure, first, the cart (31) is pulled out of the furnace from the auxiliary chamber (5) on the side of the unloading port (3), and then the outer door (9) of the auxiliary chamber (5) is pulled out. The fact that the kiln is closed as shown in Figure 1 is similar to a conventional tunnel kiln with a preliminary chamber.
At this time, the internal pressure of the preliminary chamber (5) is the same as atmospheric pressure. In the present invention, as shown in FIG.
) is closed, the inner door (11) is immediately opened by the opening control device (19) to a slight opening of, for example, about 10%. As a result, the gas in the furnace body (1) gradually flows into the preliminary chamber (5) through this gap,
Along with this, the pressure inside the furnace tends to decrease slightly, but when the pressure detection unit (17) detects this slight pressure fluctuation, the control damper (16) is immediately opened to increase the amount of air blown into the furnace, and the inner door The outside of (11) is covered with a door pocket-shaped cover (13) to completely prevent the gas inside the furnace from leaking to the outside, so fluctuations in the pressure inside the furnace near the outlet (3) are almost constant. Completely prevented. In this way, after a predetermined period of time has elapsed, the internal pressure of the preliminary chamber (5) is reduced to the outlet (
3) The pressure reaches the same level as the internal pressure of the nearby furnace body (1) and is balanced, so the opening control device (19) fully opens the inner door (11) and moves the next cart (32) into the preliminary chamber ( 5) There is no risk of fluctuations in the pressure inside the furnace when moving it into the furnace. After the trolley (32) has moved into the preliminary chamber (5) in this way, the inner door (11) is completely closed and the preliminary chamber (5) and the furnace body (
11, then open the outer door (9) and pull out the trolley (32) inside the spare room (5) to the outside, as in the past, and the same cycle is repeated thereafter. . In addition,
Is there an opening system for the loading entrance (2) side as well? 11 device (20) can be used to slightly open the inner door (10) to balance the internal pressure of the preliminary chamber (4) and the internal pressure of the furnace body (1), but the process is as explained above. Since it is the same as , the explanation will be omitted.

(Effects of the Invention) As is clear from the above description, the present invention provides a fan with a function of keeping the pressure inside the furnace constant near the inside of the inner door of the preliminary chamber at the end of the furnace body, and By using an inner door drive device that moves the trolley to the preliminary chamber after slightly opening the ff5 to balance the internal pressure in the furnace and the internal pressure in the preliminary chamber, fluctuations in the pressure in the furnace when the internal ff5 is opened can be reduced. This has been successfully prevented completely. Therefore, according to the present invention, there is no need to provide a special furnace pressure control device in the preparatory chamber to control the internal pressure of the preparatory chamber as in the past, and simply controlling the opening of the inner door can cause quality defects. Fluctuations in the pressure inside the tunnel kiln are effectively prevented. Therefore, the present invention greatly contributes to the development of industry as a tunnel kiln that eliminates the conventional problems and prevents furnace pressure fluctuations.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is a time chart illustrating the opening and closing states of the inner door. (1): Furnace body, (4), (5): Preparatory chamber, (1o), (
11) :Inner door, (14) :Fan, (19), (2
0): Opening degree control device, (31), (32): Trolley.

Claims (1)

[Claims] A preliminary chamber with an inner door is formed at the end of the furnace body of the tunnel kiln, and a fan is installed near the inside of the inner door of the furnace body to adjust the pressure inside the furnace in that area. A furnace characterized by being equipped with an opening degree control device that slightly opens the inner door after closing the outer door of the furnace to gradually introduce the furnace gas into the preliminary chamber, thereby making the internal pressure of the preliminary chamber substantially equal to the furnace internal pressure. Tunnel kiln that prevents pressure fluctuations.