JPH0118964B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heating device that effectively uses combustion heat from a burner to heat an object to be heated.

Generally, in a direct-fired heat treatment furnace in which a burner is attached to the side wall of the furnace and the combustion flame of the burner is ejected into the furnace, combustion occurs over a wide area on the surface of the object to be heated because the combustion flame is approximately cylindrical. It is not possible to make the frames face each other. For this reason, there was a drawback that radiant heat was not uniformly radiated to the heated object.

In addition, there are some that have multiple nozzles that blow out combustion flames arranged in a straight line on the furnace wall to form a flat combustion flame on the ceiling, but when the amount of combustion is reduced, the combustion In this case as well, there is a disadvantage that uniform heating is difficult to achieve because the frame is long and protrudes.

Further, since the combustion flame of fuel such as coke oven gas, blast furnace gas, mixed gas thereof, or natural gas, which is generally used in this type of burner, has an almost transparent color, the amount of radiant heat emitted is small. For this reason, the proportion of thermal energy generated by the burner that is absorbed by the object to be heated is low, and most of it is released to the outside of the furnace along with the exhaust gas, resulting in a large loss of thermal energy.

The present invention has been made in view of the above points, and is made to eject a combustion flame from a burner so as to creep onto the surface of a breathable radiator, and to cause this combustion flame and its combustion exhaust gas to flow through the breathable radiator. By making the surface of the breathable radiator red hot over a wide area, the object to be heated is heated by the radiant heat from the red-hot breathable radiator, thereby increasing uniform heating of the object and heat transfer efficiency. The aim is to improve the

Embodiments of the present invention will be described below with reference to the drawings.

First, the breathable radiator used in the present invention is made of a heat-resistant material such as metal or ceramic and formed into a net, honeycomb, fibrous, porous, etc. shape, and is made of a heat-resistant material such as metal or ceramic, and is made of a heat-resistant material such as metal or ceramic, and is made of a heat-resistant material such as metal or ceramic to form a mesh, honeycomb, fiber, porous, etc. It is a solid that has properties. However, the air-permeable radiator 1 formed in the shape of a lever plate is stretched horizontally in a heat treatment furnace as shown in the figure, and the surface 1a of this air-permeable radiator 1 is
The heated object 2 is arranged so as to face each other. In addition, through holes 3 penetrating from the surface 1a to the back surface 1b of the breathable radiator 1 are bored at predetermined intervals, and the tip of the combustion air supply pipe 5 is inserted through the ceiling wall 4 and guided into the furnace. The portion is branched via an air header 6, and its tip portion 7 is communicated with the through hole 3.
Further, the tip of the fuel supply pipe 8 inserted into the combustion air supply pipe 5 is branched via the gas header 9, and the tip 10 is extended from the center of the tip 7 to the surface 1a of the breathable radiator 1. Furthermore, by overturning the hat-shaped cap 11 at the tip 10 to prevent the fuel from ejecting vertically, the fuel is ejected from the ejection ports 12 formed radially in the horizontal direction on the periphery of the cap 11. so that In this way, the combustion flame from the burner is ejected so as to creep onto the surface 1a of the breathable radiator 1. On the other hand, the back side 1b of the breathable radiator 1 is the smoke side 1
3 to the outside, the back side 1b of the breathable radiator 1 is kept at a more negative pressure than the front side 1a. Therefore, the combustion flame of the burner and its combustion exhaust gas flow through the air-permeable radiator 1 from the front surface 1a side to the back surface 1b side. Note that 14 is a swirling vane provided in the middle of the combustion air supply pipe 5 near the tip 7, and the combustion air flows through the swirling vane 1.
4, the combustion flame is spirally swirled, so that when it is blown out onto the surface 1a of the air permeable radiator 1, the combustion flame becomes a spiral and the state of mixing with the combustion is improved.

In this way, in the heating device of the present invention, the combustion flame of the burner is ejected so as to crawl over the surface 1a of the breathable radiator 1, thereby
to become red hot. Furthermore, the back surface 1 of the breathable radiator 1
By making the combustion flame and its combustion exhaust gas flow through the breathable radiator 1 by setting b to a negative pressure than the surface 1a, the heat amount of the combustion flame and the combustion exhaust gas is transmitted to the breathable radiator 1, and the breathable radiation The temperature of the combustion exhaust gas guided to the back surface 1b of the body 1 is thereby lowered, and the combustion exhaust gas is discharged to the outside through the flue 13. In this way, the breathable radiator 1 removes heat from the combustion flame and its combustion exhaust gas.
has a particularly large amount of radiant heat emitted from the surface 1a,
This radiant heat is radiated toward the heated object 2. At this time, the surface 1a of the breathable radiator 1 is heated over a wide area by the combustion flame and its combustion exhaust gas, so radiant heat is radiated from the wide area of the surface 1a of the breathable radiator 1, and localized The object to be heated 2 can be heated uniformly while avoiding excessive heating, and the heat transfer efficiency is also high because the object to be heated 2 is heated by the radiant heat from the red-hot breathable radiator 1.

In addition, if heat exchange fins 15 are arranged on the outer peripheral surface of the combustion air supply pipe 5 as shown in the figure, the combustion exhaust gas flowing through the air permeable solid 1 is further stripped of heat by the heat exchange fins 15. The recovered heat can be used to preheat combustion air, further increasing heat recovery efficiency.

As described above in the embodiments, the heating device of the present invention jets out the combustion flame from the burner so as to crawl onto the surface of the breathable radiator, and further applies negative pressure to the back surface of the breathable radiator to cause the combustion flame to flow out. By causing the combustion exhaust gas to flow through the breathable radiator, the breathable radiator becomes red-hot, and the emitted radiant heat heats an object placed facing the surface of the breathable radiator. Compared to conventional burners that heat by radiant heat from a cylindrical combustion flame, the radiant area can be larger and the object to be heated can be heated evenly. It can be achieved. Furthermore, since the object to be heated is heated by the radiant heat from the red-hot breathable radiator, the heat transfer efficiency can be increased, and the furnace can be made more compact, among other advantages.

In the present invention, the fuel and the combustion air may be injected onto the surface of the breathable radiator through separate pipes as in the above embodiment, or alternatively, the fuel and the combustion air may be injected in advance. The premix gas may be mixed and ejected on the surface of the breathable radiator.

In addition to drilling a through-hole in the ventilated radiator as in the above embodiment and ejecting the combustion flame from the through-hole onto the surface of the ventilating radiator, a well-known burner may be installed on the inner wall of the furnace. A similar effect can be achieved by attaching the burner to a radiator and ejecting the combustion flame of the burner onto the surface of a ventilated radiator.

[Brief explanation of drawings]

The figure is a longitudinal sectional view showing one embodiment of the present invention. 1... Breathable radiator, 1a... Surface, 1b...
Back side, 2... heated object.

Claims (1)

[Claims] 1 Place the object to be heated so as to face the surface of the breathable radiator, eject the combustion flame from the burner so as to creep onto the surface of the breathable radiator, and then place the back surface of the breathable radiator toward the surface. A heating device characterized in that the combustion flame and its combustion exhaust gas are made to flow through the breathable radiator at a more negative pressure.