JP3078075B2 - Shuttle kiln - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discontinuous kiln, and more particularly to an atmosphere control for a discontinuous kiln.

[0002]

2. Description of the Related Art Conventionally, when firing ceramic bodies, it has been desired to appropriately control the atmosphere such as gas components, temperature, and pressure in a furnace. This is because a change in the atmosphere in the furnace has a great effect on the quality of the product to be fired, such as the color and the compaction. As a control device for controlling the atmosphere in the furnace, for example, as shown in FIG. Air is supplied from the blower blower 3 to the burner 2 according to the opening degree of the air damper 5 driven by the motor 4, and the fuel gas cylinder 7 is controlled according to the opening degree of the fuel gas damper 9 driven by the motor 10.
The fuel gas reduced in pressure by the pressure reducing valve 8 is supplied to the burner 2. Air and fuel gas are mixed in the burner 2,
The mixture is ignited as a mixed gas having a substantially approximate stoichiometric air-fuel ratio, and the ignited high-temperature combustion gas is blown into the furnace.

However, according to the conventional shuttle kiln , since the opening degree adjustment of the air damper and the opening degree adjustment of the fuel gas damper are manually performed by an operator, adjustment of the initial opening degree setting of both dampers and Since it is difficult to adjust the degree of opening at the intermediate time, the operation of adjusting the atmosphere in the furnace has been complicated. If the opening of the adjusting valves such as the two dampers is not proper, the atmosphere in the furnace becomes unstable due to excess and deficiency of air and fuel, so that the firing of the firing target becomes uneven and the quality of the firing target deteriorates. There is a problem.

An object of the present invention is to provide a regulating work of the flow rate control valve of fuel gas facilitates, highly capable precise atmosphere control reliability based on the time schedule sheet
The purpose is to provide a cattle kiln .

[0005]

A shuttle kiln according to the present invention for achieving the above object has a gas burner mounted on a side wall of a furnace body, an air passage for supplying air to the gas burner, and a fuel gas supplied to the gas burner. A fuel gas passage to be supplied; a plurality of shut-off valves provided in parallel with the fuel gas passage ;
A pressure reducing valve that individually sets a fuel gas flow rate according to the joule .

[0006]

According to the shuttle kiln of the present invention, the fuel gas flow rate is automatically controlled by the plurality of pressure reducing valves according to the time schedule, so that when the fuel gas flow rate is switched, the opening and closing of the shut-off valve can be switched simply. In addition, the work of adjusting the fuel gas flow rate becomes easy.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment in which the present invention is applied to a shuttle kiln.
And FIG. A gas burner 2 is provided on a side wall of the kiln 1. The air from the blower 3 is supplied to the air damper 5.
And is supplied to the gas burner 2 from the air passage 21. The fuel gas from the fuel gas cylinder 7 is supplied to the gas burner 2 from a fuel gas passage 23 through a flow control valve 22 described later. In the gas burner 2, the air and the fuel gas are mixed, and this air-fuel mixture is burned to become a combustion gas and blown out into the furnace chamber.

The supply amount of air is adjusted according to the opening of the air damper 5 driven by the motor 4. As shown in FIG. 1, the fuel gas passage constituting the flow control valve 22
Are branched in parallel into three passages 26, 27, 28 and 29, and these passages 26, 27, 28 and 29 are shut off valves 31, 3
2, 33, 34 and pressure reducing valves 41, 42, 43, 44
Are provided in series. The flow rate settings of the pressure reducing valves 41, 42, 43, and 44, which are flow rate control valves, are different from each other. And immediately after the start of firing, the first shut-off valve 3
1 is opened and the shutoff valves 32, 33, and 34 are closed, and the fuel gas flow rate is adjusted by the first pressure reducing valve 41. Next, after a certain period of time, the second shut-off valve 32 is opened, and the shut-off valves 31, 33, 3
4 is closed, and the fuel gas flow rate is adjusted by the second pressure reducing valve 42. Thereafter, the third and fourth pressure reducing valves 43 and 44 are sequentially
Adjusts the fuel gas flow rate.

FIG. 3 shows a time-dependent change in the firing temperature of the kiln and the pressure reducing valve that operates. In the areas A, B, C, and D, the shutoff valves 31, 32, 33, and 34 are sequentially opened. In the region E, the shutoff valves 31, 32, 33, 34 are all closed. The furnace temperature gradually rises from the initial stage and reaches the maximum temperature immediately before the fire is stopped. Thereafter, the furnace temperature gradually decreases.

The temperature characteristics in the furnace and the oxygen concentration in the furnace are measured by shutoff valves 31, 32, 33, and 34 and pressure reducing valve 4.
It can be changed as appropriate according to the settings of 1, 42, 43, and 44. The air flow rate and the fuel gas flow rate are controlled based on a desired time schedule. Pressure reducing valves 41, 42,
Since the flow rates of 43 and 44 are set in advance by the individual pressure reducing valves, there is an effect that the mode switching of the furnace atmosphere control becomes easy.

The above has described one embodiment.
For the present invention, the above embodiments can be changed and modified,
Obviously, the scope of the present invention will be determined by those skilled in the art.

[0012]

As described above, according to the present invention, Shah according to the present invention
According to the torque kiln , the workability of the control valve for adjusting the fuel gas flow rate by switching on / off of a plurality of shutoff valves or pressure reducing valves and combining these on / off is improved. Therefore, there is an effect that rapid firing is possible and fuel consumption can be saved. Further, since the atmosphere in the furnace chamber can be precisely controlled, there is an effect that the characteristics of the article to be fired, such as color and baking, can be finished with high quality.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a fuel gas flow control valve of a shuttle kiln according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram illustrating a shuttle kiln according to an embodiment of the present invention.

FIG. 3 is a characteristic diagram showing the relationship between the elapsed time during firing, the operating pressure reducing valve, and the furnace temperature.

FIG. 4 is a circuit diagram showing a conventional shuttle kiln .

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Kiln (furnace body) 2 Gas burner 21 Air passage 22 Flow control valve 23 Fuel gas passage 31, 32, 33, 34 Shutoff valve (Flow control valve) 41, 42, 43, 44 Pressure reducing valve (Flow control valve)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F27D 7/02 F27B 17/00 F23N 1/00 102

Claims (1)

(57) [Claims] A gas burner attached to a side wall of a furnace body; an air passage for supplying air to the gas burner; a fuel gas passage for supplying fuel gas to the gas burner; and a plurality of fuel gas passages provided in parallel with the fuel gas passage. A shut-off valve, connected in series to each of the shut-off valves, and adapted to a time schedule.
Shuttle kiln, characterized in that Flip fuel gas flow rate is a pressure reducing valve which is set individually.