JPH0444611Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a heating furnace, such as a forging furnace, which heats an object to be heated to a high temperature with high efficiency.

(Prior art and its problems) FIGS. 1 and 2 show a conventional general forging furnace. In small-scale furnaces, heating is often performed using a single burner, and in this case, the flow of combustion gas is not uniform but distributed, creating the problem that the object to be heated cannot be heated uniformly. Furthermore, most of the heat transfer at high temperatures is carried out by radiation, and in the case of a combustion furnace, most of the heat transfer is carried out by radiation from the flame. However, the amount of radiation from a flame is a fraction of the amount of radiation from a solid wall at the same temperature, and is emitted without sufficient heat dissipation, resulting in large exhaust losses and thermal efficiency, especially at high temperatures. There is an issue where the The present invention provides a heating furnace that uniformly heats objects to be heated, increases the amount of radiant heat transfer, and improves thermal efficiency, thereby eliminating the various drawbacks of the prior art.

(Means for solving the problem) Furnace body side wall 5 near ceiling wall 4 in furnace body 3
A burner 1 that forms a fan-shaped flattened flame with a slit-shaped ejection port 2 is installed in the burner 1, and the ceiling wall 4 inside the furnace body 3 forms a step in the direction of movement of the combustion gas ejected from the burner 1. The jet nozzle 2 of the burner 1 is formed in a ceiling wall 4 having a sawtooth cross section, and the jet nozzle 2 of the burner 1 is connected to a flow path 7 from the burner combustion chamber 6 to the jet nozzle 2.
The closer it is to the spout 2, the larger its cross-sectional area becomes.

(Function) The fan-shaped flattened flame ejected from the burner 1 contacts the ceiling wall 4 and transfers heat to the ceiling wall 4. The ceiling wall 4 is constructed with a sawtooth cross section that is stepped in the direction in which the combustion gas travels, so the contact area is large and sufficient heat transfer can be carried out. Generates the Coanda effect essential to invention. Therefore, the heat generated by the flame is first transferred to the ceiling wall 4 having a saw-toothed cross section, and then transferred to the object to be heated by solid radiation from the ceiling wall 4. Compared to radiant heat that relies solely on flame, the amount of heat transferred to the heated object increases,
Exhaust temperature decreases and thermal efficiency improves. That is, in the present invention, first, since the flame is a fan-shaped flat flame as shown in the figure, the flow velocity distribution in the direction perpendicular to the burner axis is uniform, and the temperature distribution in the furnace can be made uniform. The installation position of the burner 1 is near the ceiling wall which has a saw-toothed cross section, and since the flame is flat, the space between the flame and the ceiling wall 4 is narrow, and this space is attracted by the flame jet, resulting in negative pressure. A Coanda effect occurs which attracts the flame towards the ceiling wall 4 of the configuration described above. At this time, if the ceiling wall 4 does not have the above-described configuration, that is, the ceiling wall 4 has a sawtooth cross section that forms a step in the direction in which the combustion scum travels, the Coanda effect will not occur. . Therefore, the flame flows while adhering to the ceiling wall 4 having the above-described configuration, and the convection heat transfer effect is performed more effectively to heat the ceiling wall 4. Furthermore, the ceiling wall 4
Since it has the above-mentioned configuration, countless small vortices are generated in the stepped portion, and these small vortices entrain the surrounding combustion gas to further promote the Coanda effect, and these small vortices heat the stepped portion that becomes a dead space. Facilitate. In this way, the ceiling wall 4 having the above-mentioned configuration
Heat transfer to the ceiling wall 4 can be effectively planned, and strong solid radiation from the ceiling wall 4 can be obtained.

(Effects of the invention) As described above, the present invention has the advantage of being able to obtain a uniform temperature distribution over a wide range perpendicular to the burner axis, even though it is a single burner, and It has the great advantage of being able to transfer flame heat to the ceiling wall much more effectively, and by re-radiating that heat to the heated object, the amount of heat transferred increases and thermal efficiency can be greatly improved. .

[Brief explanation of the drawing]

Figures 1 and 2 are explanatory diagrams explaining the arrangement of burners and flame conditions in a conventional furnace, and Figures 3 and 4 are cross-sectional diagrams showing burners used in the present invention.
The figure is a vertical cross-section diagram, Figure 4 is an X-X ray diagram, and Figure 5 is a longitudinal diagram.
6 are explanatory diagrams of the heating furnace of the present invention. Symbols 1...burner, 2...spout, 3...furnace body, 4...ceiling wall with sawtooth cross section, 5...furnace body side wall, 6...burner combustion chamber, 7...flow furnace, 8 …
...Flame holding mechanism.

Claims (1)

[Scope of utility model registration request] A heating furnace in which a burner that forms a fan-shaped flat flame with a slit-shaped nozzle is installed on a side wall of the furnace body near the ceiling wall of the furnace body, the ceiling wall of the furnace body is configured as a ceiling wall with a sawtooth cross section that forms a step in the direction of travel of the combustion gas ejected from the burner, and the cross-sectional area of the burner nozzle is configured so that the flow path from the burner combustion chamber to the nozzle becomes larger the closer it is to the nozzle.