JP2548826Y2 - Spray cleaning device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spray cleaning device for cleaning scale attached to a secondary tube outer surface, a boundary between tubes and a tube sheet, a tube sheet surface, etc. of a steam generator for a nuclear power plant. Things.

[0002]

2. Description of the Related Art FIGS. 5 to 5 show a conventional example of an injection cleaning apparatus for cleaning scale attached to the outer surface of a pipe on the secondary side of a steam generator for a nuclear power plant, a boundary portion between pipes and a pipe sheet, a pipe sheet surface, and the like. 8, 1 is a cleaning nozzle, 1a in FIG. 8 is a straight nozzle hole drilled at the tip of the cleaning nozzle 1, 1b is a water passage hole provided in the cleaning nozzle 1, FIG.
In FIG. 6, reference numeral 2 denotes two cleaning hoses provided with the cleaning nozzle 1 at the tip, and reference numeral 3 denotes a guide pipe. Each of the cleaning hoses 2 is inserted and installed in the guide pipe 3. Reference numeral 4 denotes a support mechanism for supporting the guide pipe 3, and reference numeral 5 denotes a drainage pipe of a drainage device. The end of the drainage pipe 5 on the tube plate side is bent downward. 7 is a tube plate of a vertical heat exchanger (steam generator),
8 is a vertical heat exchanger body, 9 is a hand hole of the vertical heat exchanger body, 1
0 is a tube.

In the spray cleaning apparatus shown in FIGS. 5 to 8, the guide pipe 3 is inserted through a hand hole 9 into a tube plate 7 of a vertical heat exchanger.
The guide pipe 3 is inserted into the hand hole 9 of the vertical heat exchanger body by the support mechanism 4 and attached so as to be able to be pulled out. Then, high-pressure washing water is supplied to each washing hose 2 → the washing nozzle 1 Passage hole 1b → tube sheet 7 from straight nozzle hole 1a
The jet is injected upward as a parallel flow jet, and the scale attached to the outer surface of the tube 10, the boundary between the tube 10 and the tube plate 7, the surface of the tube plate 7 and the like is washed by inserting and withdrawing the guide pipe 3. The washing water after the washing is discharged from the drain pipe 5 of the drain device to the outside of the vertical heat exchanger body.

At this time, the drain pipe 5 of the drain device is set on the tube plate 7 of the vertical heat exchanger, and the washing atmosphere around the tube plate 7 is set to the atmospheric pressure so that the thrust of the parallel flow jet is not reduced. I have to.

[0005]

In the conventional spray cleaning apparatus shown in FIGS. 5 to 8, the high-pressure cleaning water is supplied to each cleaning hose 2 → the water passage hole 1b of each cleaning nozzle 1 → the straight nozzle hole 1a. Is sprayed onto the tube sheet 7 in the atmosphere as a parallel flow jet to clean the scale attached to the outer surface of the tube 10, the boundary between the tube 10 and the tube sheet 7, the surface of the tube sheet 7, etc. There was a problem that the hard scale could not be removed but remained, although it could be removed.

The present invention is proposed in view of the above-mentioned problems, and its purpose is not limited to the soft scale attached to the outer surface of the tube, the boundary between the tube and the tube sheet, the surface of the tube sheet, and the like. ,
It is an object of the present invention to provide a jet cleaning apparatus capable of quickly removing hard scales and achieving high efficiency of cleaning work, shortening of processes, and reduction of exposure.

[0007]

In order to achieve the above object, the present invention provides a jet cleaning apparatus in which a cleaning hose provided with a cleaning nozzle at a tip is inserted into a guide pipe and installed therein. The nozzle hole is provided at the end of the water passage hole in a tangential direction to the water passage hole, and the nozzle hole is constituted by a parallel throat portion and a subsequent tapered opening portion.

[0008]

[Action] Insert the guide pipe into the tube plate of the heat exchanger,
The guide pipe is supported by a support mechanism so that it can be inserted and withdrawn, and then high-pressure washing water is used for washing hoses → water passage holes for each washing nozzle → parallel throat portions of nozzle holes provided tangentially to these water passage holes → The tapered portion of the nozzle hole following the parallel throat portion → The jet is sprayed onto the tube sheet as a diffusion water jet, and the scale attached to the outer surface of the tube is washed by inserting or pulling out a guide pipe. This cleaning can be performed in water. In this case, the water is supplied from the water supply pipe of the water supply device onto the tube sheet, while the water is drained from the drain pipe of the drainage device, the water is poured on the tube sheet at an appropriate depth, the washing nozzle is submerged, and the first opening taper is formed. The jet of the diffused water flow from the section is jetted as a turbulent jet with a large degree of turbulence. The turbulent jet in the air and water has a high-frequency velocity fluctuation component in the jetting direction of the jet water immediately after leaving the nozzle, and this acts as an oscillating pressure on the surface to be cleaned. Is obtained. In particular, in the case of a turbulent jet (underwater), besides the above-described action, there is a wake action that strongly accelerates surrounding water, and these actions further improve excavation removal performance at a close distance. Therefore, the outer surface of the pipe,
The hard scale as well as the soft scale adhering to the boundary between the tube and the tube sheet, the surface of the tube sheet, and the like are quickly removed, so that the efficiency of the cleaning operation, the shortening of the process, and the reduction of the exposure are achieved at the same time.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a jet cleaning apparatus according to the present invention will be described with reference to an embodiment shown in FIGS.
Is a nozzle hole drilled at the tip of the washing nozzle 1, 1b is a water passage hole provided in the washing nozzle 1, and the nozzle hole 1a
From the end of the water passage hole 1b parallel throat portion 1a ₁ provided tangentially to the water passage hole 1b, it is formed by opening the previous subsequent angle θ between the tapered portion 1a _2.

Reference numeral 2 denotes a cleaning nozzle provided with the washing nozzle 1 at the tip.
The cleaning hoses 3 are guide pipes, and the cleaning hoses 2 are inserted and installed in the guide pipes 3. 4
Is a supporting mechanism for supporting the guide pipe 3, 5 is a drainage pipe of a drainage device, 6 is a water supply pipe of a water supply device, and the ends of the drainage pipes 5 and 6 are bent downward.

7 is a tube plate of a vertical heat exchanger (steam generator),
8 is a vertical heat exchanger body, 9 is a hand hole of the vertical heat exchanger body, 1
0 is a tube. Next, the operation of the spray cleaning device shown in FIGS. 1 to 3 will be specifically described. Guide hole 3 with hand hole 9
From above into the tube plate 7 of the vertical heat exchanger, the guide pipe 3 is inserted into the hand hole 9 of the vertical heat exchanger body by the support mechanism 4 and attached so as to be able to be drawn out. Cleaning hose 2 → Water passage hole 1b of each washing nozzle 1 → Parallel throat portion 1a ₁ of nozzle hole 1a provided tangentially to this water passage hole 1b → Point of nozzle hole 1a following this parallel throat portion 1a ₁ Angle θ from open tapered portion 1a ₂ onto tube sheet 7
(Θ = approximately 8 ° to 30 °) (see FIG. 3) while jetting as a diffusion water jet and inserting or pulling out the guide pipe 3 to make the outer surface of the pipe 10 or the boundary between the pipe 10 and the pipe sheet 7 And the scale adhered to the tube plate 7 surface and the like.

This cleaning can be performed in water. In this case, while water is supplied from the water supply pipe 6 of the water supply apparatus onto the tube sheet 7, the water is drained from the drain pipe 5 of the drainage apparatus, and the water is poured onto the tube sheet 7 to a water depth h (water depth of about 100 mm). by submerging the respective cleaning nozzles 1, as previously open diffusion flow Jietsuto disturbance large degree disturbance Jietsuto from the tapered portion 1a _2, ejects.

FIG. 4A shows a parallel flow jet (air) obtained by the conventional parallel flow nozzle, and FIG. 4B shows a turbulence jet (air) obtained by the turbulent jet nozzle of the present invention. 3C shows a turbulent jet (underwater) obtained by the turbulent jet type nozzle of the present invention. The parallel flow jet (aerial) A obtained with the conventional parallel flow type nozzle shows the peak value of the excavation and removal performance at a position far away from the tip of the cleaning nozzle. Cleaning provides only low excavation removal performance.

On the other hand, the turbulent jet (in the air) B and the turbulent jet (in the water) C obtained by the turbulent jet type nozzle of the present invention have a high-frequency speed fluctuation in the jetting direction of the jet water immediately after leaving the nozzle. Since there is a component, this acts as a vibration pressure on the surface to be cleaned, and high excavation removal performance can be obtained even at a short distance. In particular, in the case of the turbulent jet (underwater) C, in addition to the above-described action, there is a wake action that strongly accelerates surrounding water, and these actions further improve the excavation removal performance at a close distance.

[0015]

[Table 1]

Table 1 shows the same injection pressure, the closest injection distance,
The measurement results of the erosion amount when water is sprayed toward the lead plate at the spray time are shown. As is apparent from Table 1, the erosion amount is the largest in the case of turbulent jet (underwater) C.
In addition, it has been confirmed that when a parallel flow jet is injected into water, it is attenuated more than when it is injected into the air.

[0017]

[Effect of the Invention] The spray cleaning apparatus of the present invention inserts a guide pipe into the tube plate of the heat exchanger as described above, supports the guide pipe so that it can be inserted and pulled out by a support mechanism, and then performs high-pressure cleaning. Water washing hose → Water passage hole of each washing nozzle → Parallel throat part of nozzle hole provided tangentially to this water passage hole → Tapered end of nozzle hole following this parallel throat part → To tube sheet Inject as a diffusion water jet and insert or pull out a guide pipe to clean the scale attached to the outer surface of the pipe. This cleaning can be performed in water. In this case, the water is supplied from the water supply pipe of the water supply device onto the tube sheet, while the water is drained from the drain pipe of the drainage device, the water is poured on the tube sheet at an appropriate depth, the washing nozzle is submerged, and the first opening taper is formed. The jet of the diffused water flow from the section is jetted as a turbulent jet with a large degree of turbulence. The turbulent jet in the air and water has a high-frequency velocity fluctuation component in the jetting direction of the jet water immediately after leaving the nozzle, and this acts as an oscillating pressure on the surface to be cleaned. Is obtained. Especially turbulent jet (underwater)
In the case of, in addition to the above-mentioned action, there is a wake action that strongly accelerates the surrounding water, and these actions further improve the excavation removal performance at a close distance. Therefore, it is possible to quickly remove not only the soft scale attached to the outer surface of the pipe, the boundary between the pipe and the pipe sheet, the surface of the pipe sheet, but also the hard scale, thereby improving the efficiency of the cleaning work, shortening the process, and reducing the exposure. Can be achieved.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view showing an embodiment of a jet cleaning apparatus according to the present invention.

FIG. 2 is an enlarged side view of a cleaning nozzle of the spray cleaning device.

FIG. 3 is a vertical sectional front view taken along line XX of FIG. 2;

FIG. 4 is an explanatory diagram comparing the cleaning performance of the jet cleaning device of the present invention and a conventional jet cleaning device.

FIG. 5 is a vertical sectional side view showing a conventional spray cleaning device.

FIG. 6 is a plan view thereof.

7 is a vertical sectional front view taken along the line YY in FIG. 6;

FIG. 8 is an enlarged side view of a cleaning nozzle of the spray cleaning device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Washing nozzle 1a Nozzle hole 1a ₁ Parallel throat part 1a ₂ First opening taper part 1b Water passage hole 3 Guide pipe

Claims (1)

(57) [Scope of request for utility model registration] 1. A jet cleaning device in which a cleaning hose having a cleaning nozzle provided at a tip end is inserted into a guide pipe and installed, wherein a nozzle hole of the cleaning nozzle is provided at an end of the water passage hole with respect to the water passage hole. A spray cleaning device provided in a tangential direction, wherein the nozzle hole is constituted by a parallel throat portion and a tapered portion that opens first.