JPS6344432B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention is a cleaning device for removing deposits such as scale on the inner surface of a pipe, especially for long (approximately 15 to 20 m long) thin pipes of condensers used in thermal power plants, etc. The present invention relates to a device for cleaning the inner surfaces of thin tubes of equipment used in the food, petrochemical, and other fields where chemical cleaning is not suitable.

Traditionally, in order to clean the inside of a pipe, a pig or bar-shaped scrubber is inserted into one end of the pipe, and pressure water or compressed air is supplied into the pipe, and the pressure is used to move the pig or bar-shaped scrubber towards the other end of the pipe. Although it is known that slime-like soft deposits can be removed, scale and hard deposits cannot be removed. Additionally, a nozzle capable of spouting high-pressure water of approximately 300 kg/cm ² is attached to the end of a flexible water supply hose, the nozzle is inserted into the pipe, and high-pressure water is spouted backwards from the nozzle, causing the nozzle to advance with the reaction. Ultra-high pressure jet cleaning is also used to remove deposits, but
This method uses high-pressure water, which requires special workers, and cleaning is uneven, and even if it is possible to remove dead shells, it is not possible to completely remove scale. Furthermore, a dry blasting method is also known, in which the inside of the pipe is completely dried, and a gun capable of ejecting blasting material such as alumina particles with completely dehumidified compressed air is used, and cleaning is performed with the blasting material ejected from the gun. The inside of the pipe must be completely dried to prevent the dust removed from sticking to the inner surface of the pipe before work can be carried out, and there is a risk of workers inhaling the dust during work, which poses a sanitary problem. There is. There are also other problems, such as the blasting material not coming out evenly from the gun, creating bridges in the tank before reaching the gun and not reaching the gun, and the blasting material scraping and damaging the inner surface of the tube.

In order to solve the above-mentioned conventional problems, the present invention supplies a mixture of blasting material with liquid under pressure to a gun, which is a cleaning device, and squirts the liquid mixed with the blasting material into the pipe from the gun to remove deposits inside the pipe. It was designed to remove and clean the fluid, and it has a liquid supply port where the blasting material mixed liquid is supplied, and a gas supply port where driving compressed air is supplied to blow out the blasting material mixed liquid into the pipe by an ejector action. a pressurized air supply port; a discharge port for spouting the blasting material mixed liquid into the pipe together with pressurized air;
A string-like body that extends forward from the discharge port and can enter the pipe, and is connected to the tip of the string-like body and is propelled through the pipe by a jet stream containing blasting material mixed in from the discharge port. A collision body of blasting material,
The present invention is characterized by comprising a cord-like body payout control means for controlling the propulsion of the colliding body within the tube by controlling and paying out the string-like body.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In Figures 1 and 2, 1 is a gun which is a cleaning device of the present invention, and has an elongated cylindrical body 2, and from the front end of the cylindrical body 2, which is thinner than the cylindrical body 2, is inserted into one end of the pipe p to be cleaned. A plungeable discharge port 3 projects forward. The cylindrical body 2 has an air chamber 5 at the rear into which compressed air is blown from an air supply port 4, and the front end of the air chamber 5 communicates with a nozzle tube 6 that is concentrically formed in double layers within the cylindrical body and projects forward. do. The front end of the nozzle tube 6 is located within the tapered rear end of the discharge port 3, and a blasting material is installed in the tube so that the front end of the nozzle tube 6 communicates with the area where the rear end of the discharge port 3 is located. A liquid supply port 7 for supplying mixed liquid and a cleaning water supply port 8 are provided so as to maintain a receding angle.

The rear end of the cylindrical body, that is, the open rear end of the air chamber 5 is sealed by screwing in a plug 9. This plug 9 penetrates the air chamber 5, the nozzle tube 6, and the discharge port 3,
A forward-facing auxiliary cylinder 10 protruding from the front end of the discharge port 3
The central hole 11 passing through the plug 9 and the auxiliary tube 10 has a reel 12 installed on the air supply port 4.
A strong string-like body 13 such as nylon thread or stainless steel thread is fed out from the auxiliary tube 10, and the colliding body 14 having a diameter slightly smaller than the inner diameter of the tube is connected to the tip of the string-like body protruding from the auxiliary tube 10.

The discharge port 3 holds an O-ring 15 in an annular groove on its outer periphery, and when inserted into the pipe p, the O-ring comes into contact with the inner periphery of the pipe. For this reason, it is preferable to prepare several types of discharge ports with different outer diameters depending on the inner diameter of the pipe to be cleaned, and to connect them to the front end of the cylindrical body 2 so that they can be replaced by screwing or the like.

To clean the inner surface of the pipe p using this cleaning device, the discharge port 3 is loaded inside one end of the pipe p, compressed air from an air compressor is fed into the air supply hole 4,
A blasting material mixed liquid in which blasting material is suspended in water is supplied to the liquid supply hole 7 by a pump or the like. The particle size of the blasting material is about 100 μm, and the material is determined depending on the material of the tube. For example, if the tube is made of copper, it is glass beads, if it is made of stainless steel, it is alumina, and if it is a soft tube, it is polypropylene. Also, the volume ratio of the blasting material to the liquid is about 20 to 45%, and the pressure of compressed air is about 5 to 45%.
Approximately 7Kg/cm ² G is sufficient.

As a result, the air blown into the air chamber 5 from the air supply port 4 is accelerated and passes through the cylindrical gap between the inner circumference of the nozzle tube 6 and the outer circumference of the auxiliary tube 10, and passes between the inner circumference of the discharge port 3 and the auxiliary tube 10. When flowing into the cylindrical space between the outer peripheries of the blasting material, the liquid mixed with the blasting material supplied to the liquid supply port 7 is sucked in under negative pressure, and the air, liquid, and blasting material are instantaneously mixed uniformly and discharged in a mist state. Collider 14 ejects into the tube from the front end of 3 and is connected to the tip of string-like body 13.
It is diffused and blows between the collision body and the inner surface of the tube toward the other end of the tube while pressurizing the collision body forward. If there is scale or other deposits on the inner surface of the tube, the blasting material will flow through the tube in a laminar flow until it is diffused by the colliding body, and the deposits will be scraped off by the blasting material. When blowing through, the blasting material increases the speed to increase the effect of scraping the deposits, and there is a recess on the inner surface of the tube, so the blasting material enters the recess and effectively cleans the inside of the recess. be able to. Figures 3 and 4 show the state in which the above-mentioned blasting material is grinding away deposits on the inner surface of the tube. In particular, Figure 4 shows the concavities of deposits caused by the turbulent flow as it blows around the impactor. This shows that the blasting material is also grinding the inside. Since the blasting material uses water as a cushion to grind away deposits, the ground surface is extremely smooth.

Therefore, the reel 12 is gradually rotated against the forward pressurization of the colliding body by the jet flow from the discharge port 3 to feed out the string-like body, and the colliding body 14 is directed from one end of the pipe to the other end. By slowly propelling the tube, deposits inside the pipe can be removed very effectively. Then, when the colliding object reaches the other end of the tube,
The cleaning is interrupted, the string is wound onto a reel, the impactor 14 is pulled back to the front end of the outlet, the outlet is pulled out from one end of the tube, and the outlet is now loaded into the other end of the tube.
The cleaning may be repeated in the same manner by propelling the impactor from the other end of the tube toward one end. By cleaning again from the other end of the pipe in this way, the pitting corrosion area (crater) of deposits that could not be removed during the previous cleaning can be removed.
can also be removed.

The speed at which the impactor 14 is moved within the tube is appropriately determined depending on the thickness of deposits attached to the inner surface of the tube.
Of course, the collision body 14 is not limited to always moving within the pipe during cleaning, and may be moved by a required amount and then stopped for a required period of time. Further, the rear part of the impactor is preferably formed into a conical or cone shape with the top facing backward in order to facilitate the diffusion of the ejected flow.

During the cleaning operation, the blasting material, water, and grinding debris of deposits scraped by the blasting material are discharged from one end of the pipe p. It is desirable to reuse the blasting material and water, and to process and recover the grinding waste. Fifth
The figure shows an example in which the blasting material and water are used in circulation as described above, and cleaning is performed while collecting grinding debris.

A recovery chamber 18 is disposed at the end of the pipe p opposite to the end where the discharge port 3 is loaded, through which the air in the room is exhausted to the outside by an exhaust fan 17 through a filter 16, and is provided through the chamber wall. The outer end of the blow pipe 19 is connected to the end of the pipe p by pressing it or adsorbing it with a suction cup, and the water, blasting material, and grinding debris discharged from the pipe p are taken into the collection chamber 18, and the water, blasting material, and grinding debris are taken into the collection chamber 18 and collected using a wire mesh or the like. The particles of blasting material, sewage, and grinding debris that have been damaged due to the difference in specific gravity are introduced into the chamber 20 from the bottom as an overflow, then extracted from the bottom of the chamber 20 and blown into the cyclone separator 21 by a pump. The blasting material is discharged from the upper part into the processing tank 22, and the reusable blasting material is returned to the bottom of the collection chamber 18 from the lower part.

The treatment tank 22 has a chamber 24 which receives the effluent from the upper part of the cyclone separator 21 into an overbag 23.
It has an aggregation chamber 25 into which the liquid from this chamber 24 overflows and a flocculant introduced into it, and a pit 26 into which the supernatant liquid overflows from the aggregation chamber. Therefore, crushed particles of blasting material, grinding waste, etc. can be collected in the overbag 23, clean water is returned from the pit 26 to the collection chamber 18, and excess water is drained by overflow or the like. Further, the precipitates coagulated and precipitated in the coagulation chamber 25 are appropriately removed from the bottom of the coagulation chamber 25 by a drain. or,
The chamber 20 detects the water level in the tank and supplies makeup water 27 when water is insufficient.

Then, the blasting material mixed liquid is drawn out from the bottom of the recovery chamber 18 by a pump 28 and supplied to the liquid supply port 7 of the gun 1. By recycling the blasting material and water in this manner, cleaning can be carried out very economically.

Note that if the operation of the pump 28 is stopped after cleaning one pipe and during the preparation period until the next pipe is cleaned, the blasting material will settle to the bottom of the collection chamber, and the blasting material must be immersed in water for cleaning. Suspension requires several minutes to operate the pump and stir the water and blasting material in the circulation system 29. To eliminate this starting operation, a two-way switching valve 30 is installed at the liquid supply port 7, and the pump 28
By switching the valve 30, the blasting material mixed liquid flowing through the hose 31 can be supplied to the liquid supply port 7 and to the recovery chamber 18 through the return hose 32. When supplying the blasting material mixed liquid and interrupting operation, use the switching valve 30.
, the blasting material mixed liquid may be flowed through the return hose 32, and the blasting material in the recovery chamber may be kept in a floating state at all times.

Furthermore, if the on-off valves V ₄ and V 8 are provided in the air supply port 4 and the washing water supply port ₈ , respectively, as in this embodiment, the on-off valve V ₄ can be closed before or after the washing operation.
V ₈ can be opened to allow cleaning water to flow into the pipes to wash the inside of the pipes. Also, after cleaning and rinsing, open/close valve V ₄
You can also open the V8, close the _V8 , and run compressed air through the tube to dry it. In either case, the liquid mixed with blasting material is returned from the switching valve 30 to the hose 3.
2, return it to the recovery chamber 18 and keep it circulating. All of these steps can be easily performed with Gun 1 at hand.

In addition, in cases where chemical cleaning can be performed, such as condenser pipes in thermal power plants, instead of washing with water before cleaning, acid or alkali can be poured into the pipes to chemically clean them and soften the deposits. Deposits can be removed in a shorter time.

The main effects of the present invention are listed below.

(1) Suitable for cleaning pipes where chemical cleaning cannot be applied due to the nature of the plant, and other pipes where conventional dry blasting would cause scratches on the inside of the pipe. In other words, when cleaning according to the present invention, the average wall thickness reduction on the inner surface of the tube is 3 to 5μ, and there is no problem at all.
This is because water is used as a cushion for grinding, so the ground surface is finished smoothly.

(2) It can perform harder cleaning than ultra-high-pressure jet cleaning, the equipment cost is low, and the work can be done safely without requiring workers with special skills.

(3) Unlike the dry blasting method, workers do not inhale blasting material or grinding debris during cleaning work, which is superior in terms of environmental hygiene.

(4) Can perform high-grade surface treatment such as pipe inner lining.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; Fig. 1 is a cross-sectional plan view of the main part of the device during cleaning, Fig. 2 is a side view of the same, and Fig. 3 shows how the blasting material mixed in is attached to the inner surface of the tube. Enlarged explanatory diagram showing the state in which the kimono is removed, No. 4
The figure is an enlarged view of Figure 3, and Figure 5 is an explanatory diagram of the entire state in which blasting material etc. are being cleaned while being collected.
In the figure, 3 is a discharge port, 4 is an air supply port, 7 is a liquid supply port, 1
Reference numeral 3 indicates a string-like body, 12 a reel exemplified as a means for controlling the feeding of the string-like body, and 14 a colliding body.

Claims (1)

[Scope of Claims] 1. A liquid supply port through which the blasting material mixed liquid is supplied, and a pressurized air supply port through which driving compressed air is supplied for ejecting the blasting material mixed liquid into the pipe by an ejector action. , a gun equipped with a discharge port inserted into the end of the pipe in order to eject the blasting material mixed liquid into the pipe together with pressurized air; and a string-shaped gun that extends forward from the discharge port and enters the pipe. a colliding body connected to the tip of the string-like body, which collides and diffuses a jet flow containing a liquid mixed with blasting material ejected from the discharge port, and is thereby propelled through the pipe; and the string-like body. An apparatus for cleaning inside a pipe, comprising a cord-like body payout control means for controlling the propulsion of the colliding body within the pipe by controlling and paying out the string-like body. 2. In the pipe cleaning device according to claim 1, the fluid supply port of the gun is connected to a circulation pipe that supplies the blasting material mixed liquid ejected from the discharge port through the blasting material processing device. Device.