JPH05280867A - Corner jet fire type kiln - Google Patents

Abstract

PURPOSE:To make it possible to eliminate temperature variability and calcine a large number of articles to be calcined to a satisfactory extent by installing an auxiliary burner to the upper part of a furnace inside in such a fashion that it may provide a specified angle to the flow direction of a whirling current. CONSTITUTION:Burners 13 to 16 are laid out at each corner of a furnace main body along each furnace wall. Each of auxiliary burners 17 to 20 is laid out in the upper part of each furnace wall in the central part respectively. Each of the auxiliary burners 17 to 20 is positioned in a slightly higher elevation than the highest stage of the burners 13 to 16. Each auxiliary burner provides an angle ranging from 30 deg. to 90 deg. to the wall surface. Since the auxiliary burners are installed to reduce the velocity of a whirling current of high temperature gas, the central upper part in the furnace is turned to a distribution area of high temperature gas as well, which eliminate temperature variation in the furnace as a result.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corner jet fire type firing furnace in which a burner is provided at a corner portion of a furnace body and a high temperature gas is swirled in the furnace to fire an article to be fired.

[0002]

2. Description of the Related Art Conventionally, in this type of firing furnace, as shown in FIG. 6, burners 2, 3, 4 and 5 are arranged at respective corners of a furnace body 1 having a rectangular shape. There is. Four burners 2, 3, 4 and 5 are provided at the upper and lower portions of each corner.

However, when firing a product to be fired,
Fire a flame from each burner 2, 3, 4 and 5
The hot gas is swirled in the furnace as shown by the arrow and discharged from the furnace floor.

[0004]

However, in the above-mentioned conventional case, there is temperature unevenness, that is, the temperature of the upper part of the central part of the furnace is lower than that of the furnace wall side. There is a risk that the placed product to be fired may be defective due to insufficient firing temperature, or the long product to be fired may be broken due to a large temperature difference between the upper part and the lower part. Therefore, in the past, the product to be fired was not placed in the upper center of the furnace, but the good placement range was not clearly known, and it was inevitable to widen the non-fired product region in the center of the furnace. I have to. However, this has a problem in that the number of products to be produced is reduced and the arrangement work is troublesome, and the productivity as a whole is lowered.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a corner jet fire type firing furnace which can satisfactorily fire many articles to be fired without temperature unevenness in the furnace. .

[0006]

DISCLOSURE OF THE INVENTION The present invention is a corner jet fire type firing furnace in which a burner is provided in a corner portion of a furnace body and a high temperature gas is swirled in the furnace to fire an article to be fired. It is characterized in that an auxiliary burner is provided in the upper portion at a predetermined angle with respect to the flow direction of the swirling flow in order to reduce the flow velocity of the swirling flow of the hot gas.

In this case, the predetermined angle is preferably 30 ° to 90 °.

[0008]

When the high temperature gas is injected into the furnace by the burners at the corners of the furnace body, the high temperature gas becomes a swirling swirl flow, and the high temperature gas distribution region does not exist in the upper center of the furnace. However, according to the above means, an auxiliary burner having a predetermined angle with respect to the flow direction of the swirl flow is provided in order to reduce the flow velocity of the swirl flow of the hot gas. It becomes a distribution area, and as a result,
The uneven temperature inside the furnace is eliminated.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

First, referring to FIGS. 1 and 2, the furnace body 11 is shown.
Has a rectangular box shape with an open lower surface. On the lower surface of the furnace body 11, the firing carriage 12 that functions as a hearth.
Is designed to be moved up and down. The firing cart 12
An exhaust port 12a is provided at the center of the.

Burners 13, 14, 15 and 16 are arranged at the corners of the furnace body 11 along the respective furnace walls. Four burners 13, 14, 15 and 16 are provided at the upper and lower sides of each corner.

Auxiliary burners 17, 18, 19 and 20 are provided in the upper central portions of the furnace walls of the furnace body 11, respectively.
Are arranged. Each of the auxiliary burners 17, 18, 19 and 20 is located at a position slightly higher than the uppermost one of the burners 13 to 16 and is substantially horizontal and is inclined at a predetermined angle α with respect to the furnace wall. The predetermined angle α is 3 with respect to the flow direction of the swirling flow (with respect to the wall surface).
It has an angle of 0 ° to 90 °.

Further, the furnace body 11 is provided with temperature sensors 21, 22, and 23, which are, for example, thermocouples. The temperature sensors 21 and 22 are arranged in the upper and lower portions of the furnace wall on the right side, and the temperature sensor 23 is arranged in the central portion of the ceiling wall.

Here, in FIG. 3, the auxiliary burners 17 and 1 are shown.
The piping system and control system for 8, 19, and 20 are shown. Each auxiliary burner 17, 18, 19 and 20 has a solenoid valve 2 individually attached to the fuel supply piping system.
4, a pressure responsive valve 25 and a manual valve 26 are provided.

Further, the combustion air piping system is provided with a common control valve 27 and an individual manual valve 28. Further, the secondary air piping system is provided with a common control valve 29 and an individual manual valve 30. In this way, the auxiliary burner control system 31 is configured.

The control valves 27 and 29 in the burner control system 31 are designed so that their opening degrees are controlled by an adjusting device 32.
Is adapted to feedback control the opening of the control valves 27 and 29 based on the temperature detection signal from the temperature sensor 19 so as to match the temperature control schedule given from the temperature control device 33. In this case, the fuel supply amount is controlled by controlling the opening degree of the pressure-responsive valve 25 according to the air pressure (air amount) of the combustion air piping system. Note that the feedback control is, for example, setting an optimum temperature distribution at each position in the furnace, and comparing the measured temperature at each position with the gas ejection amount of the auxiliary burner, the ejection amount, the ejection direction, and the gas in accordance with it. It is to control the temperature and so on.

The burners 13, 14, 15 and 1
A burner control system (not shown) configured in the same manner as the auxiliary burner control system 31 similar to the above is provided for each of the upper two of 6, and the temperature sensor 21
The above-mentioned control is performed on the basis of the temperature detection signal from the temperature sensor 22. Further, although not shown, similar burner control systems are provided for the two lower parts, and the temperature detection from the temperature sensor 22 is performed. The same control as described above is performed based on the signal.

Now, in the above-mentioned structure, when the article to be fired is fired, the burners 13, 14, 15 and 16 are simply used.
When the hot gas is injected from the hot gas, the hot gas becomes a swirling swirl flow. However, according to the present embodiment, a predetermined angle (α = 30 ° to 90 °) with respect to the furnace wall, in other words, it is provided so as to reduce the flow velocity of the swirling flow of the high temperature gas. The size and depth of the vortex formed by the swirling flow are reduced, and the temperature difference between the upper and lower sides is reduced. Therefore, all the products to be baked arranged in the product-to-be-baked product arrangement region (denoted by reference numeral H in FIG. 2) are excellently baked.

FIG. 5 shows the temperature difference distribution in the furnace. Now, the temperature difference Δt is equal to
Is a value obtained by subtracting the temperature of each of the detection points B, C, D from the outside temperature at (this is the temperature of the detection points A, E in FIG. 4). Lines Ja, Jb in FIG. 4 are auxiliary burners 17,
The temperature difference between the upper portion and the lower portion in the article-to-be-baked arrangement region H in the case where 18, 19, and 20 are not used are respectively shown. In this case, the temperature difference Δt was 20 to 25 ° C.

Lines Ha and Hb in the figure are auxiliary burners 17,
The temperature difference between the upper portion and the lower portion in the article-to-be-baked arrangement region H of the present example using Nos. 18, 19 and 20 is shown. In this case, the temperature difference Δt is 2.5 to 5.
As low as 0 ° C. The temperature difference in this case can be reduced by feedback control based on the temperature detection signal of the temperature sensor 23.

[0021]

As is apparent from the above description, the present invention provides an auxiliary burner in the upper part of the furnace with a predetermined angle with respect to the flow direction of the swirling flow in order to reduce the flow velocity of the swirling flow of the hot gas. Since it is provided, the temperature difference between the upper side and the lower side in the furnace can be reduced, and a large number of articles to be fired can be favorably fired.
It has an excellent effect that productivity can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional plan view showing an embodiment of the present invention.

[Fig. 2] Front view in vertical section

FIG. 3 is a diagram showing a control system

FIG. 4 is a cross-sectional plan view showing a temperature detection point.

FIG. 5 is a diagram showing a temperature difference distribution in the furnace.

FIG. 6 is a diagram showing a conventional example.

[Explanation of symbols]

Reference numeral 11 is a furnace body, 12 is a firing carriage, 13, 14, 15 and 16 are burners, 17, 18, 19 and 20 are auxiliary burners, 21, 22 and 23 are temperature sensors, and 31 is an auxiliary burner control system.

Claims (2)

[Claims] 1. A corner jet fire type firing furnace in which a burner is provided at a corner portion of a furnace main body and a high temperature gas is swirled in the furnace to sinter a product to be fired, a swirling flow of the high temperature gas is provided in an upper part of the furnace. Corner jet fire type firing furnace, characterized in that an auxiliary burner is provided at a predetermined angle with respect to the flow direction of the swirling flow in order to reduce the flow velocity. 2. The corner jet fire type firing furnace according to claim 1, wherein the predetermined angle is 30 ° to 90 °.