JPH0629643B2 - Smoke tube boiler - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention provides a protective plate having an air passage hole at the smoke tube inlet end of a smoke tube boiler, leaving a space for a slight air insulating layer, or
Alternatively, at least one fresh air or a seal air supply pipe for supplying low-temperature waste gas discharged from the smoke pipe is provided between the protective plate and the boiler end plate on the heat insulation wall of the fire chamber in the vicinity of the smoke tube boiler, thereby providing the boiler. The present invention relates to a smoke tube boiler designed to prevent overheating of the tube end portion of the smoke tube.

[Conventional technology]

When a conventional boiler burns under high load and becomes smaller, the temperature of the inlet gas at the smoke pipe inlet of the smoke pipe boiler rises, the smoke pipe expansion part is easily damaged by overheating, etc., and the expansion part loosens or water leaks. Or, it was easy for cracks to occur at the edge bends.

In order to prevent the occurrence of these defects, conventionally, a ferrule as shown in FIG. 5 was attached to the smoke pipe inlet of the boiler.

[Problems to be solved by the invention]

When a ferrule as shown in FIG. 5 is attached to a conventional boiler smoke pipe, the temperature of the ferrule becomes the same as the temperature of the hot gas at the inlet in a steady state after a certain period of time. That is, the smoke pipe end is constantly exposed to this high temperature because the hot ferrule is always in contact with the smoke pipe end. Therefore, in the long-term use of the boiler, even in this case, there are many problems in that the smoke pipe expanding portion is damaged due to overheating and loosens to cause water leakage.

[Means for solving problems]

In view of the above, the first aspect of the present invention has an air circulation hole having an inner diameter of d = 0.5D to D, where D is the inner diameter of the smoke tube, at the smoke tube inlet end of the smoke tube boiler in order to prevent damage due to heating of the smoke tube expansion portion. As shown in FIG. 1, the protective plate is provided at the inlet of the smoke pipe so that the air circulation hole comes to the inlet of each smoke pipe. The second is an attached smoke tube boiler, the second of which is the first invention as shown in FIG. 3 and further includes at least one fresh air between the protective plate and the boiler end plate or low temperature exhaust gas discharged from the smoke tube. The present invention provides a smoke tube boiler in which a seal air supply pipe for supplying air is provided on a fire chamber heat insulating wall around a smoke tube boiler.

More preferably, as shown in FIG. 4, the ends of the seal air supply pipes provided on the heat insulation wall of the firebox reach the openings of the boiler smoke tubes and are opened.

It is preferable that the shape of the protective plate is a simple circular flat plate and is made of high-quality heat-insulating and heat-resistant material such as ceramic, and it is not always necessary to make it as a single plate-shaped member, and it is possible to divide it appropriately or to cool the cooling area part. It is desirable to increase the cooling effect by using different materials for the cooling area by dividing.

When the size of d is less than 0.5D, the contraction effect and exudation effect described later are small, the object of the present invention is not achieved, and D
If d is exceeded, the above effect is significantly diminished, so d = 0.
Must be 5D-D.

[Action]

The protection plate and the seal air supply pipe are provided in the present invention as shown in FIG. 6 because the hot combustion gas enters each of the boiler smoke pipes through the hole of d of the protection plate and the contraction action thereof is performed. The high-temperature combustion gas is so arranged that it does not come into direct contact with the end portion of the smoke pipe curving portion or the like at a certain distance therefrom.

Further, by supplying cooling air (sealing air) or low-temperature waste gas discharged from the smoke pipe to positively provide a heat insulating layer effect between the protective plate and the end plate, the cooling air is supplied to each smoke pipe tube. The pipe end is heat-insulated and cooled so as to flow into the smoke pipe, and the so-called "bleed-out cooling" effect is expected.

〔Example〕

 The present invention will now be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view of an embodiment in which a protective plate (5) of the present invention is provided in an opening of a smoke pipe (2), and FIG. 2 is a front view of FIG. 1 (1) Is a boiler end plate, (2) and (2 ') are smoke pipes, and (5) is a protection plate, which is fixed to the boiler end plate (1) at the inlet of the smoke pipe by mortar (4). Each of the smoke tube inlet ends has an air passage hole having a diameter of (d). The size of (d) is 0.
Depending on the diameter (D) of the boiler smoke pipe in 5D-D, for example, 0.5D, 0.7
It is decided as D, 0.8D. FIG. 3 shows an embodiment in which a seal air supply pipe for supplying fresh air or low-temperature waste gas discharged from a smoke pipe to the fire chamber heat insulating wall together with the protective plate (5) is provided on the fire chamber heat insulating wall around the smoke tube boiler. FIG. 4 is a vertical cross-sectional view of one embodiment in which the ends of the seal air supply pipes provided on the heat insulation wall of the firebox reach the openings of the boiler smoke pipe, respectively. Since the temperature distribution at the edges is not uniform, a plurality of seal air supply pipes (11) are installed to extend between the protective plate (5) and the end plate (1) in order to further increase the cooling effect. The effect of cooling the end of the smoke tube is further enhanced by making it come to the end of the smoke tube.

FIG. 5 is a vertical cross-sectional view showing a part of a conventional smoke tube boiler having a ferrule (3) at the smoke tube end.

FIG. 6 shows an example of a state in which the protective plate (5) is attached slightly away from the end of the smoke tube to jet the protective plate opening to the contraction portion which is an orifice.

〔The invention's effect〕

According to the present invention, the smoke tube end and the end plate with the smoke tube are directly exposed to radiant heat from the hot gas of the firebox as compared to a smoke tube boiler with a conventional ferrule to protect the smoke tube end of the smoke tube boiler. It is possible to prevent overheating at the end of the smoke pipe, and to completely eliminate problems such as leaks, cracks, and water leaks at the end of the smoke pipe. It became even more promoted. Moreover, the protective plate and the cooling air supply pipe of the present invention have remarkable effects such as very inexpensive installation.

[Brief description of drawings]

1 is a vertical sectional view of an embodiment of the present invention, FIG. 2 is a schematic front view of the present invention, and FIGS. 3 and 4 are vertical sectional views of another embodiment of the present invention, respectively. FIG. 6 is a schematic cross-sectional view of a boiler smoke pipe end in which a conventional ferrule is installed at the smoke pipe end, and FIG. 6 is a diagram showing a state of a contraction portion and a jet flow in which openings of each protective plate are orifices. 1 ... Boiler end plate, 2 ... Smoke tube, 3 ... Ferrule 4 ... Mortar, 5 ... Protection plate, 6 ... Boiler water 7 ... Firebox, 8 ... Firebox insulation wall, 9 ... Steel plate 10 …… Body plate, 11 …… Cooling air supply pipe

Claims (5)

[Claims] 1. The inner diameter of the smoke pipe is D at the smoke pipe inlet end of the smoke pipe boiler.
Then, a protective plate having an air circulation hole with an inner diameter of d = 0.5D to D is provided to the extent that an air insulation layer space is generated from the smoke tube end at the smoke tube inlet so that the air circulation hole comes to the smoke inlet. A smoke tube boiler characterized by being mounted slightly away from the smoke tube end. 2. The smoke tube boiler according to claim 1, wherein a protective plate is used which is divided into different materials. 3. The smoke tube boiler according to claim 1, wherein a protective plate is used in which a cooling area portion of the protective plate is divided into different materials. 4. The inner diameter of the smoke pipe is D at the smoke pipe inlet end of the smoke pipe boiler.
Then, a protection plate having an air circulation hole with an inner diameter of d = 0.5D to D is attached to the smoke tube inlet so that the air circulation hole comes to the smoke tube inlet, and further between the protection plate and the boiler end plate. A smoke tube boiler, wherein a seal air supply pipe for supplying at least one fresh air or a low temperature gas discharged from the smoke pipe to the air heat insulating layer space is provided on a heat insulating wall of a fire chamber in a peripheral portion of the smoke tube boiler. 5. The smoke tube boiler according to claim 4, wherein the seal air supply pipes provided on the heat insulation wall of the firebox are provided so that the respective pipe ends reach and open to the opening of the boiler smoke pipe.