JPH1030886A - Pottery kiln with burner block - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pottery kiln where about 1300 deg.C temperature is available from even with a city gas whose supply pressure is 0.02kg/cm<2> in a pottery kiln by increasing the height of a burner block for a fire opening and changing the ratio of the diameter to the length in the axial direction within the range from 2.0 to 4.0. SOLUTION: In a pottery kiln which is provided with a Bunsen gas burner 1 which sucks up combustion air by a fuel gas ejection pressure, facing a fire opening on a furnace floor 2, a burner block 4 is set up on the fire opening 3 of the furnace floor 2 where the shape of a combustion compartment 5 is designed based on the ratio of the diameter on the upstream side to the length in the longitudinal direction ranging from 2.0 to 4.0 so as to provide a specified high temperature with a fuel gas source whose supply pressure is low.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pottery kiln used for firing ceramics, and more particularly to a pottery kiln which can use low-pressure household gas as fuel.

[0002]

2. Description of the Related Art Conventionally, as a fuel, LPG fuel is often used, and as a structure of a pottery kiln A ', as shown in FIG. A short burner block 24 is provided. The Bunsen gas burner 21 is attached to the lower part of the furnace with the burner block 24 facing the burner block 24.
A method called a collapsible type in which the gas is discharged from the flue 27 through the flue gas is common and practical. When the fuel is LPG gas, the gas pressure is 0.3 kg to 0.5 kg / cm ^2.
In addition, if the gas was jetted from the nozzle, the combustion air could be sufficiently sucked in, and the mixing with the gas was sufficiently performed, so that a high furnace temperature of 1300 ° C. could be obtained. However, under the current situation in which the use of city gas 13A has spread, a pottery kiln using city gas as a fuel has been required, but there has been no pottery kiln that can cope with it.

[0003]

With the structure of a conventional ceramic art kiln, if the Bunsen gas burner 21 alone is replaced with a city gas burner, the furnace temperature becomes 1300 ° C. as in the prior art.
It was found that high temperatures could not be obtained. Household supply pressure of city gas is 13A, 12A, 11A, maximum pressure 250m
mAq ~ minimum pressure 100mmAq, maximum pressure 220m at 6A
mAq ~ minimum pressure 70mmAq, maximum pressure 2 at 5A, 4A etc.
It is from 00 mmAq to a minimum pressure of 50 mmAq. 200MmAq = water column pressure 200mmH ₂ O = 0.02k
g / cm ² Accordingly, the supply pressure of the city gas is that much lower compared to about 0.02 kg / cm ² and LPG of 0.3kg~0.5kg / cm ² was found to be responsible for up.

The conventional burner block 24 shown in FIG. 6 is short and has a diameter to length ratio of about 1.0 to 1.5.
Although the primary flame extending from the burner head through the burner block 24 supplies the secondary air to the surroundings, the secondary air is immediately released into the expanded furnace as shown by the arrow, and the secondary air is effectively used. It is easy to discharge without being operated, and in the case of city gas, the gas ejection pressure is LPG
As compared with the above, the degree of contact and mixing of the secondary air is weak, and the secondary air is discharged without complete combustion. That is, the combustion air sucked in as the secondary air does not spend all for combustion only, and not only part of it is discharged as it is, but also the role of lowering the furnace temperature by removing the furnace temperature. do. Therefore, even if this conventional structure is applied to a pottery kiln using city gas as a fuel, the kiln temperature required is one.
A high temperature of 300 ° C cannot be obtained, especially in the firing process of ceramics, and a high temperature of 1300 ° C cannot be obtained by main firing.
This is problematic because desired ceramics cannot be fired.

[0005] The present invention solves such a problem, and the burner block is also used as a hearth in a conventional inverted flame pottery kiln, but the shape is a cylindrical combustion chamber. The ratio of diameter to axial length is about 1.0-1.5
Met. By increasing the height of the burner block and changing the ratio of its diameter to its axial length between 2.0 and 4.0, the inventor can reduce the amount of gas ejected while passing through the burner block. By sufficiently promoting the mixing of the sucked air and complete combustion, it is possible to easily obtain a high temperature of 1300 ° C., which was not increased by the conventional city gas, and a maximum of 145 ° C.
It has been found that the temperature can be raised to 0 ° C. Therefore, the present invention specifies the shape of the combustion chamber of the burner block and the ratio between the diameter and the length of the burner block. Since the supply pressure of the city gas cannot be changed, the supply pressure of the city gas is 0.02 kg / c.
It is an object of the present invention to provide a pottery kiln capable of obtaining a sufficiently high firing temperature of about 1300 ° C. even with m ² .

[0006]

According to a first aspect of the present invention, there is provided a pottery kiln with a burner block, wherein a Bunsen-type gas burner 1 for sucking combustion air at a pressure at which fuel gas is jetted faces a crater 3 of a hearth 2. In the pottery kiln equipped, the shape of the combustion chamber 5 is adjusted so that the ratio of the upstream diameter D to the axial length L is a fuel gas of a gas type having a low supply pressure and a predetermined high firing temperature is obtained. A burner block 4 having a range of 2.0 to 4.0 is installed at a crater 3 of a hearth 2.

According to a second aspect of the present invention, the combustion chamber 5 has a cylindrical shape or a frusto-conical shape having an expansion angle θ of 12 degrees or less.

According to a third aspect of the present invention, as the burner block 4, a plurality of burner blocks 4a each having a cylindrical combustion chamber 5 corresponding to a gas type are laminated.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment of the present invention, the shape of the combustion chamber 5 of the burner block 4 of the falling flame pottery kiln A is cylindrical.
Or the frustoconical shape with a spread angle θ of 12 degrees or less,
The ratio of the upstream diameter D to the axial length L is 2.0 to 4.0.
The burner block 4 is set in the crater 3 of the hearth 2 below the pottery kiln A.

The fuel gas supplied to the gas burner 1 is a city gas supplied at a low pressure, for example, 13 A, and the gas supplied from the gas supply pipe is ejected from a gas nozzle and enters a mixing pipe through a gas mixer head. The air for combustion is sucked from the primary air hole by the output power of the gas, and the air ratio at this time is adjusted by the primary air adjustment damper. The primary mixture of gas and air passes through the mixing tube, reaches the burner head flame, draws in secondary air from around the burner head, starts burning, and passes through the burner block 4 in the pottery kiln A. After burning and reaching the ceiling, it is discharged from the stack through a drawhole in the hearth and a flue.

According to the present invention, even for city gas supplied at low pressure, such as for household use, the burner block 4 is extended from the burner head by setting the ratio of the upstream diameter D to the axial length L to 2.0 to 4.0. The primary flame is mixed with the secondary air sucked from around the burner head and burns while effectively contacting it inside the burner block 4 longer than before, resulting in complete combustion, and this flame is guided into the pottery kiln. Thus, the temperature of the furnace can be set to about 1300 ° C. necessary for firing, a change in the color of the glaze, a delicious firing color can be obtained, and the desired ceramics can be fired.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1 to FIG. 3, A is a falling flame type pottery kiln equipped with a Bunsen type gas burner 1 that sucks combustion air at a pressure at which fuel gas is ejected, and one or a plurality of craters 3 on both sides of a hearth 2. The refractory burner block 4 having the combustion chamber 5 is installed, and the gas burner 1 faces. City gas having a low supply pressure, for example, 13A, 12A, 1
1A etc. are supplied. The burner block 4 has a cylindrical shape as shown in FIG. 3 or a frusto-conical shape with a spread angle θ of 0 to 12 degrees as shown in FIG. Is in the range of 2.0 to 4.0. That is, L = 2.0 to 4.0D. Reference numeral 6 denotes a recess in the furnace wall where the burner block 4 is installed.

The burner block 4 having a narrow cylindrical shape burns better, but the load on the combustion chamber is correspondingly large and the burner block may crack. As shown in FIG. 4, by making the shape of the combustion chamber of the burner block 4 into a frusto-conical shape with a spread angle θ of 12 degrees or less, the combustion is good and the load on the burner block does not increase so much. Can be improved in durability. The reason why the expansion angle θ of the combustion chamber is set to 12 degrees or less is that if the angle is set to 12 degrees or more, in the combination of the fuel gas supplied at a low pressure and the Bunsen gas burner, the mixing with the air becomes poor, and the combustion state itself becomes poor, and the initial state This is because the purpose cannot be achieved.

In FIG. 5, reference numeral 4a denotes a refractory burner block having a short length 1 and one or a plurality of combustion chambers 5 having a cylindrical shape. In this example, the burner block 4 is formed by stacking three stages.
As for the burner block 4 as a whole, the ratio of the diameter D to the length L of the combustion chamber is set to 2.0 to 4.0 as described above. The recess 6 in the furnace wall is formed in accordance with the length of the stacked burner blocks.

In FIG. 1, 7 is a gas supply pipe of the pottery kiln A, 8 is a copper pipe, 1 is a Bunsen type gas burner, 9 is a burner head, 10 is a ceiling of the pottery kiln A, 11 is a draw hole, 1
2 is a flue and 13 is an exhaust stack. Reference numeral 14 denotes an opening / closing door which opens and closes by turning a handle, and 15 denotes a peephole for observing a combustion state. Although the above-described embodiment has been described with reference to the inflammation type ceramic art kiln, the present invention is not limited to this, and the burner block of the present invention can also be installed at the crater of a flame-rising type kiln.

Since the present invention has the above configuration, the city gas 13
Even if household fuel gas supplied at a low pressure is used in A, the combustion chamber of the burner block 4 is lengthened, the ratio of the upstream diameter D to the axial length L is set to 2.0 to 4.0, and cylindrical or By forming a frusto-conical shape having an expansion angle of 12 degrees or less, the primary flame extending from the burner head 9 mixes with the secondary air sucked from around the burner head 9 while effectively contacting the inside of the burner block 4 which is longer than before. By burning it, complete combustion takes place, and this flame is guided into the furnace of the pottery kiln A. In addition to the furnace temperature of about 1300 ° C. necessary for firing, a Bunsen gas burner is used. A temperature of 1450 ° C. was obtained for the first time as a pottery kiln. Therefore, according to the pottery kiln, a desired high firing temperature can be obtained in the main firing which is important in the pottery firing process.

[0017]

According to the pottery kiln with a burner block according to the first aspect of the present invention, the shape of the combustion chamber of the burner block having the combustion chamber installed on the hearth immediately above the gas burner is changed to the upstream diameter and the axial length. By setting the height ratio in the range of 2.0 to 4.0, the primary flame extending from the burner head effectively contacts the secondary air sucked from around the burner head in the burner block longer than before. When mixed and burned, complete combustion occurs, and this flame is guided into the furnace of the pottery kiln. Therefore, a fuel gas of a low supply pressure gas type, for example, a city widely used in homes In a pottery kiln using gas 13A as a fuel, not only is the furnace temperature required for firing to be a predetermined high firing temperature of about 1300 ° C., but also a pottery kiln using a Bunsen gas burner for the first time at 1450 ° C. Temperature is obtained, therefore, to be able to perform firing pottery at low city gas having a gas pressure is obtained by a convenient. Therefore, according to this pottery kiln, since it can be fired at a high temperature in the main firing process, which is important for firing pottery, it is possible to change the color of the glaze, and also to obtain a rich flavored firing color, from the beginner You can produce pottery products that professionals expect.

Further, as an effect, the amount of gas used is reduced by 20% as compared with the prior art. This is also caused by the fact that the use of a burner block longer than before reduces the air which does not participate in the combustion, resulting in the so-called theoretical air combustion. This is due to the close combustion.

According to the second aspect of the present invention, since the shape of the burner block is set to the above ratio and the cylindrical shape or the spread angle is set to 12 degrees or less, the flame extending from the burner head is effectively brought into contact with the secondary air. And complete combustion. If the spread angle of the combustion chamber is a frustoconical shape of 12 degrees or less, the combustion state is good, the load on the combustion chamber is not so large, and the durability of the burner block can be improved.

According to the third aspect of the present invention, the number of stacked burner blocks can be changed according to the type of gas supplied at low pressure, and the ratio of diameter to length can be changed. A predetermined high temperature, about 1300 degrees, can be obtained with fuel.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing a pottery kiln with a burner block according to the present invention.

FIG. 2 is a side sectional view of the same.

FIG. 3 is an enlarged sectional view of a burner block having a cylindrical combustion chamber.

FIG. 4 is an enlarged sectional view of a burner block having a frusto-conical combustion chamber.

FIG. 5 is an enlarged sectional view showing an embodiment in which burner blocks alone are stacked.

FIG. 6 is a partially sectional front view showing a conventional pottery kiln with a burner block.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Gas burner, 2 ... Hearth, 3 ... Crater, 4 ... Burner block, 4a ... Burner block only, 5 ... Combustion chamber.

Claims (3)

[Claims] 1. A pottery kiln having a Bunsen type gas burner (1), which sucks combustion air at a pressure at which fuel gas is ejected, facing a crater (3) of a hearth (2), has a low supply pressure. The shape of the combustion chamber (5) is set so that the ratio of the upstream diameter D to the axial length L is 2.0 to 4.0 so that a fuel gas of a gas type and a predetermined high firing temperature can be obtained. A pottery kiln with a burner block, wherein the burner block (4) is set at the crater (3) of the hearth (2). 2. The ceramic pottery with a burner block according to claim 1, wherein said combustion chamber (5) has a cylindrical shape or a frusto-conical shape having an expansion angle θ of 12 degrees or less. 3. A pottery kiln with a burner block according to claim 1, wherein a plurality of burner blocks (4a) each having a cylindrical combustion chamber (5) corresponding to a gas type are laminated as said burner block (4).