JP2004293994A - Medium spraying apparatus and nozzle head for medium spraying apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nozzle head for a medium spraying apparatus, simple in structure, and obtaining excellent heat resistance by an inexpensive means without a heat insulating material. <P>SOLUTION: The nozzle head 3 is surrounded with a cylindrical radiation heat shielding wall 5. In the radiation heat shielding wall 5, the tip part thereof is bent inward to form a curved part 31, thereby preventing heat from entering the nozzle head 3, and an end opening part 9 is provided to decrease a difference in temperature in the direction of thickness of the radiation heat shielding wall 5. The nozzle head 3 is isolated from the radiation heat shielding wall 5 by a space part 30 to reduce a temperature rise due to transfer of heat. In order to facilitate replacement of radiation heat shielding wall 5 in its deterioration, the wall is removably fitted to a low-temperature swivel tube 2 by screw cramp 7 and/or welding 8. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a furnace wall medium blowing device for cleaning a boiler tube of a boiler furnace wall, and more particularly to a nozzle head for a medium blowing device that prevents burning and cracking of the nozzle head due to thermal history, thermal shock, etc., and achieves a long life.
[0002]
[Prior art]
FIG. 5 is an explanatory diagram of a conventional medium blowing device, FIG. 6 is a cross-sectional view of a conventional nozzle head for a medium blowing device, and FIG. 7 is a conventional dual structure nozzle for a medium blowing device. It is sectional drawing of a head.
[0003]
Boiler tubes installed on the wall of a furnace such as a coal-fired boiler have ash and other combustion products attached to the surface, resulting in a decrease in thermal efficiency. Therefore, in order to periodically inject an injection medium such as steam to remove deposits and restore thermal efficiency, a furnace wall medium blowing device is installed as shown in FIG. 5 (see, for example, Patent Document 1).
[0004]
Reference numeral 1 denotes a medium blowing device, which mainly includes a nozzle head 3 for injecting an injection medium 11 such as steam and compressed air to a boiler tube 12 provided on a wall surface 14 of the furnace 10 and a supply pipe 13 for supplying the injection medium 11. The swivel tube 2 is composed of a drive device (not shown) composed of a swivel tube 2 and a rack 16 and a pinion 17 for taking the swivel tube 2 into and out of the furnace 10. Reference numeral 15 denotes deposits deposited on the surface of the boiler tube 12.
[0005]
As shown in FIG. 6, the swivel tube 2 has a supply pipe 13 for supplying an injection medium such as water vapor and compressed air therein, an end face sealed in a hemispherical shape, and an injection medium 11 ejected on a circumferential surface. It is comprised from the nozzle head 3 provided with the nozzle hole 4 (for example, refer patent document 2).
[0006]
The removal operation of the medium blowing device 1 is performed by retracting the swivel tube 2 to make the nozzle head 3 stand by in the vicinity of the furnace wall 14 and periodically (for example, 3 to 4 times / day) to place the nozzle head 3 in the furnace 10. While being inserted and rotated, the jetting medium 11 is sprayed onto the boiler tube 12 to remove the deposited matter 15 deposited thereon. After the removal is completed, the swivel tube 2 is retracted again, and the nozzle head 3 is drawn out from the furnace 10 to the vicinity of the furnace wall 14 and is kept on standby.
[0007]
By such a removal operation, the nozzle head 3 is heated to 650 to 950 ° C. by radiation from the furnace 10 during standby, and exposed to the atmospheric temperature 1200 to 1300 ° C. in the furnace simultaneously with insertion into the furnace. When the ejection medium is ejected, a complicated thermal history such as rapid cooling at the temperature of the ejection medium (250 to 400 ° C.) is received, and a large temperature difference occurs between the inside and outside of the nozzle head 3. By repeating such removal operation, the nozzle head 3 has (1) material deterioration due to high temperature and thermal history (oxidation, σ embrittlement, creep, thermal fatigue, etc.), and (2) thermal shock and cracking due to material deterioration. The life of the swivel tube 2 was significantly reduced. Since the swivel tube 2 having a crack in the nozzle head 3 is replaced with a new swivel tube 2, the reduction in the life of the swivel tube 2 increases the cost of the swivel tube 2 as well as the running cost of the medium blowing device 1.
[0008]
As a means for preventing damage due to the thermal history and thermal shock of the nozzle head 3 as described above, as shown in FIG. 7, 18 is a casing, and the nozzle head 3 is covered with a heat insulating material 20 to form a double structure. A device has been devised in which a space is provided between the front end of the casing 18 and the front end of the nozzle head 3, the heat insulating material 19 is filled, and the connection head 21 is attached to the nozzle head 3. The casing 18 uses 40Ni-33Cr-3Al steel having excellent heat resistance and corrosion resistance, and the heat insulating materials 19 and 20 use ceramic fibers that can be used up to 1500 ° C. If the nozzle head 3 is protected by the structure and material as described above, the life of the nozzle head 3 can be extended (for example, see Patent Document 3).
[0009]
[Patent Document 1]
Japanese Patent Laid-Open No. 5-5515 (FIG. 2)
[Patent Document 2]
Japanese Patent Laid-Open No. 11-108305 (FIGS. 1 and 2)
[Patent Document 3]
JP 2000-65337 A (paragraph number [0013] and FIG. 1)
[0010]
[Problems to be solved by the invention]
An object of the present invention is to provide a nozzle head for a spraying device that has a simple structure and is excellent in heat resistance by an inexpensive means without using a heat insulating material. .
[0011]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the present invention according to claim 1 is directed to a nozzle head for a fluid blowing device that injects a fluid to clean a boiler tube in a boiler furnace, and shields radiant heat from the boiler furnace. The radiant heat shielding means is provided on the outer periphery of the nozzle head, and a space is provided between the nozzle head and the radiant heat shielding means.
[0012]
According to the said structure, the radiant heat from the boiler furnace which heats a nozzle head can be shielded. The radiant heat shielding means is heated by radiant heat, but since a space is provided between the nozzle head and the radiant heat shielding means, it is possible to reduce or prevent the temperature of the nozzle head from rising due to heat transfer from the radiant heat shielding means. .
[0013]
In order to solve the above problem, according to a second aspect of the present invention, in the nozzle head for a medium blowing device according to the first aspect, the fluid ejected from the nozzle head is conducted to the radiant heat shielding means. A conduction port is provided.
[0014]
According to the above configuration, by providing the radiant heat shielding means with the opening through which the fluid ejected from the nozzle head is conducted, the nozzle head is provided with the radiant heat shielding means, thereby blocking the ejection medium ejected from the nozzle head. Can be injected into the boiler tube.
[0015]
In order to solve the above-mentioned problem, the present invention according to claim 3 is characterized in that in the nozzle head for a medium blowing device according to claim 1 or 2, an opening is provided at an end of the radiant heat shielding means. And
[0016]
According to the above configuration, the high-temperature fluid in the boiler furnace is introduced into the inside of the radiant heat shielding means to flow, the inside is heated against the temperature drop related to the radiation of the relatively low temperature nozzle head, and the radiant heat shielding is performed. The temperature difference in the thickness direction of the means can be reduced. When the radiant heat shielding means is closed without an opening, the internal temperature is reduced by the nozzle head, the temperature difference in the thickness direction of the radiant heat shielding means is increased, and material deterioration due to heat of the radiant heat shielding means is accelerated.
[0017]
In order to solve the above-mentioned problem, the present invention according to claim 4 is the nozzle head for a fluid blowing device according to claim 3, wherein the end of the radiant heat shielding means is curved inward. And
[0018]
According to the said structure, the radiant heat which injects from the opening of the edge part of the said radiant heat shielding means can be reduced by curving the edge part of a radiant heat shielding means inside, and making a shadow with respect to a nozzle head.
[0019]
In order to solve the above-mentioned problem, the present invention according to claim 5 is the nozzle head for a fluid blowing device according to any one of claims 1 to 4, wherein the radiant heat shielding means is provided with an attaching / detaching means. It is characterized by that.
[0020]
In order to solve the above problem, according to a sixth aspect of the present invention, in the nozzle head for a medium blowing device according to the fifth aspect, the attaching / detaching means is a screw.
[0021]
In order to solve the above problem, the present invention according to claim 7 is characterized in that in the nozzle head for a fluid blowing device according to claim 5, the attaching / detaching means is welding.
[0022]
According to the above configuration, by providing the radiant heat shielding means with the attaching / detaching means, it is possible to easily replace the radiant heat shielding means subjected to the radiant heat and having deteriorated the material. Compared with the case where the nozzle head is replaced, it is effective both in terms of work and economy. When the attaching / detaching means is a screw or welding, the radiant heat shielding means can be easily replaced.
[0023]
In order to solve the above problem, according to an eighth aspect of the present invention, in the nozzle head for a fluid blowing device according to any one of the first to seventh aspects, the diameter of the end of the nozzle head is reduced. It is characterized by that.
[0024]
According to the above configuration, the nozzle head can be made small in diameter, and the diameter of the radiant heat shielding means can be made the same as that of the swivel tube so as to be compact.
[0025]
In order to solve the above problem, the present invention according to claim 9 is a medium blowing device for injecting a fluid to clean a boiler tube in a boiler furnace, according to any one of claims 1 to 8. The nozzle head for a medium blowing device described above is provided.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of a nozzle head according to an embodiment of the present invention, FIG. 2 is an explanatory view of the vicinity of the nozzle head in a removing operation according to the embodiment of the present invention, and FIG. 3 is an embodiment of the present invention. FIG. 4 is a sectional view in which the diameter of the nozzle head according to the embodiment of the present invention is reduced. 1 to 7, the same reference numerals are given to the same components, and duplicate descriptions thereof are omitted.
[0027]
In FIG. 1, reference numeral 5 denotes a cylindrical radiant heat shielding wall surrounding the nozzle head 3, and the radiant heat shielding wall 5 forms a curved portion 31 by curving the tip portion inward to prevent heat input to the nozzle head 3. Further, an end opening 9 is provided to reduce the temperature difference in the thickness direction of the radiant heat shielding wall 5. The nozzle head 3 and the radiant heat shielding wall 5 are separated by a space 30 to reduce the temperature rise of the nozzle head 3 due to heat transfer. In order to facilitate replacement when the radiant heat shielding wall 5 is deteriorated, the radiant heat shielding wall 5 is attached to the swivel tube 2 having a low temperature by screwing 7 and / or welding 8. The material of the radiant heat shielding wall 5 may be a heat resistant metal similar to that of the nozzle head 3 and does not require special heat resistant steel.
[0028]
In FIG. 2, after the nozzle head 3 is inserted into the furnace, the injection medium 11 is supplied from the supply pipe 13 into the swivel tube 2, and the injection medium 11 is made to correspond to the nozzle hole 4 and the nozzle hole 4 while rotating. The deposit 15 is removed by spraying from the spray opening 6 of the radiant heat shielding wall 5 provided to the boiler tube 12. In the meantime, the nozzle head 3 is prevented from abrupt temperature rise due to radiant heat from the surroundings by the radiant heat shielding wall 5, and the thermal shock is alleviated. In addition, the inner surface of the radiant heat shielding wall 5 is heated by the inflow of high-temperature fluid from the end opening 9, the temperature difference in the thickness direction is reduced, and the thermal stress is reduced.
[0029]
In FIG. 3, when the removal of the deposits on the boiler tube 12 is completed, the swivel tube 2 is pulled out of the furnace, and the nozzle head 3 also stands by in the vicinity of the furnace wall 14. Meanwhile, the nozzle head 3 can be prevented from being heated by radiation from the furnace 10 by the radiant heat shielding wall 5, and the temperature of the nozzle head 3 can be suppressed to 600 ° C. or less.
[0030]
In FIG. 4, in order to avoid an increase in the diameter of the nozzle head 3 by attaching the radiant heat shielding wall 5, the nozzle head 3 is made smaller in diameter and the diameter of the radiant heat shielding wall 5 is made the same as that of the swivel tube 2 to make it compact.
[0031]
【The invention's effect】
As described above, according to the present invention, the nozzle head provided at the tip of the swivel tube surrounds the nozzle head and has an opening corresponding to the nozzle hole of the nozzle head surrounding the nozzle head and the inner edge of the nozzle head. By providing a radiant heat shielding wall with a part, the temperature of the nozzle head due to radiation in the furnace is lowered without using a heat insulating material, and material deterioration due to high temperature and thermal history (oxidation, σ embrittlement, creep, thermal fatigue) Etc.), cracks due to thermal shock and material deterioration are prevented, and the radiant heat shielding wall itself has a longer life due to the reduction of thermal stress due to the opening at the tip, and as a result, the life of the swivel tube can be extended.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a nozzle head according to an embodiment of the present invention.
FIG. 2 is an explanatory view of the vicinity of a nozzle head in a removing operation according to an embodiment of the present invention.
FIG. 3 is an explanatory view of the vicinity of a nozzle head in standby according to an embodiment of the present invention.
FIG. 4 is a cross-sectional view in which a diameter of a nozzle head according to an embodiment of the present invention is reduced.
FIG. 5 is an explanatory diagram of a medium blowing device according to a conventional technique.
FIG. 6 is a sectional view of a nozzle head for a medium blowing device according to a conventional technique.
FIG. 7 is a cross-sectional view of a nozzle head for a double-layer medium blowing device according to the prior art.
[Explanation of symbols]
3 Nozzle head 5 Radiant heat shielding wall 6 Injection opening 7 Screwing 8 Welding 9 End opening 30 Space 31 Curved part

Claims (9)

In the nozzle head for a medium blowing device for injecting fluid to clean the boiler tube in the boiler furnace, the nozzle head includes a radiant heat shielding means for shielding radiant heat from the boiler furnace, and the nozzle head. A nozzle head for a medium blowing device, wherein a space is provided between the radiant heat shielding means. 2. The nozzle head for a medium blowing device according to claim 1, wherein the radiant heat shielding means is provided with a conduction port through which fluid ejected from the nozzle head is conducted. The nozzle head for a fluid blowing device according to claim 1 or 2, wherein an opening is provided at an end of the radiant heat shielding means. The nozzle head for a medium blowing device according to claim 3, wherein an end portion of the radiant heat shielding means is curved inward. The nozzle head for a medium blowing device according to any one of claims 1 to 4, wherein an attaching / detaching means is provided on the radiation heat shielding means. The nozzle head for a medium blowing device according to claim 5, wherein the attaching / detaching means is a screw. The nozzle head for a medium blowing device according to claim 5, wherein the attaching / detaching means is welding. The nozzle head for a medium blowing device according to any one of claims 1 to 7, wherein a diameter of an end portion of the nozzle head is reduced. A medium blowing device for injecting a fluid to clean a boiler tube in a boiler furnace, comprising the nozzle head for a medium blowing device according to any one of claims 1 to 8.

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