JPH02262962A - Cylindrical inner face grinding device - Google Patents

Abstract

PURPOSE:To make high water pressure and abrasives act synergistically so as to surely remove foreign matter from the cylindrical inner face in an especially short work time by forming grinding space by the disc of a grinding head and the sealing means, and ejecting high pressure water inside this grinding space and also letting slurry, which includes abrasives, flow out. CONSTITUTION:When a grinding head 2 is inserted into a cylinder 1, grinding space being caught by two sheets of discs 3 and 4 is formed inside the cylinder 1 by the two sheets of discs 3 and 4 and the sealing means 5. If high pressure water is ejected from a jetting nozzle 9 and slurry, which includes abrasives, is let out from an outflow pipe 8 in this condition, the mixed water of high pressure water standing in the grinding space and slurry becomes agitated jet flow, and by the actions of high water pressure and abrasives, the inner face of the cylinder 1 can be ground efficiently in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cylindrical inner surface cleaning device for removing harmful foreign matter such as oxide scale attached to or formed on a cylindrical inner surface using water pressure. .

[Prior Art] On the inner surface of a shaft that is exposed to high temperatures for a long time, such as a steam turbine shaft in a power plant, the surface of the member is oxidized and oxide scale is formed. Also, during periodic inspections, it is necessary to remove this oxidized scale and expose the bare surface in order to check for defects.

Conventionally, in order to remove such oxidized scale, a roller grindstone is rotated and inserted into the cylindrical inner surface of the shaft.
We are doing the cleaning work, but it takes a huge amount of time for each shaft.

For example, when removing oxidized scale from the inner surface of a shaft with a diameter of 120 mm and a length of 6000 mm, 140
It took up to 200 hours of work.

Incidentally, such problems are not limited to steam turbine shafts in power plants, but similarly exist in various cylinders on which harmful foreign substances are likely to adhere and form on the inner surface.

[Problems to be Solved by the Invention] The present invention has been proposed to solve the problems of the prior art as described above, and its purpose is to reliably remove foreign substances from the inner surface of a cylinder in a short working time. It is an object of the present invention to provide an excellent cylindrical inner surface polishing device that can perform the following tasks.

[Means for Solving the Problems] The present invention focuses on the fact that foreign matter on the inner surface of a circular tube such as a heat exchanger is removed using high-pressure jet water,
This technology has been developed to allow cleaning of the inner surface of the cylinder by jetting high-pressure water and flowing out slurry containing abrasive material.

That is, the present invention provides a polishing head that is inserted into a cylinder and jets high-pressure water and at the same time discharges a slurry containing an abrasive material to clean the inner surface of the cylinder, and a high-pressure water generating means that generates high-pressure water. , a high-pressure water supply means for supplying the generated high-pressure water to the polishing head, a recovery tank for recovering excess water containing the abrasive material in the cylinder, and a stirring system for stirring the water containing the abrasive material in the recovery tank. A stirrer that suspends the abrasive material to form a slurry; a slurry supply means that supplies the formed slurry to the polishing head; a first drive mechanism that linearly moves the polishing head in the axial direction; and a polishing head. A second drive mechanism that rotates the cylinder to both sides about its axis, and a third drive mechanism that rotates the cylinder to both sides about its axis. and a sealing means for sealing between the outer periphery of each disk and the cylindrical inner surface of the two disks of the same diameter, in which the polishing head is arranged parallel to each other at a constant interval and supported integrally;
An opening for surplus water overflow provided in at least one of the discs, and a high-pressure water injection means and a slurry outflow means supported by one of the discs and arranged such that the open end thereof is located between the two discs. It is characterized by having the following.

[Function] The function of the present invention having the above configuration is as follows.

That is, when the polishing head is inserted into the cylinder, the two disks and the sealing means form a cleaning space sandwiched between the two disks within the cylinder. In this state, if high-pressure water is injected and the slurry containing the abrasive material flows out, the mixed water of the high-pressure water and slurry that accumulates in the cleaning space becomes an agitation jet, which creates high water pressure and the abrasive material. Due to this action, the inner surface of the cylinder can be efficiently polished in a short time.

The first to third drive mechanisms can move the cleaning head in the axial direction, rotate the cleaning head around the axis, and rotate the cylinder. By performing this polishing work, the entire inner surface of the cylinder can be polished.

In addition, surplus water from this polishing work overflows from the opening provided in the disk and is collected in a collection tank, so the water in this collection tank is stirred with an agitator to form a slurry. By supplying the slurry to the polishing head, repeated cleaning operations can be performed. Therefore, the abrasive material can be used without wasting it.

Furthermore, if the second and third drive mechanisms are configured to reciprocate the polishing head or cylinder in small increments, a more effective stirring jet can be formed and the efficiency of the polishing work can be improved.

[Embodiment] An embodiment of the cylindrical inner surface polishing device according to the present invention will be specifically described below with reference to FIGS. 1 to 3. here,
FIG. 1 is a perspective view showing the whole, FIG. 2 is a cross-sectional view in the axial direction showing the state of the cleaning operation, and FIG. 3 is a cross-sectional view in the direction perpendicular to the axis.

In FIG. 1, 1 is a cylinder and 2 is a polishing head. The polishing head 2 seals between two disks 3.4 on the supply side and the overflow side that are arranged in parallel with a certain interval, and the outer periphery of each disk 3, 4 and the inner surface of the cylinder 1. A sealing elastic body 5, an opening 4a for excess water overflow provided in the disk 4 on the overflow side, a support member 6 that integrally connects the two river disks 3 and 4, and a support member 6 inserted in the middle of the support member 6. It consists of a high-pressure water injection nozzle unit 7 and a slurry outlet pipe 8 that is arranged parallel to the support member 6 and has a slurry outlet 8a near the high-pressure water injection nozzle unit 7. Here, as shown in FIG. 2, the position of the overflow opening 4a is such that a sufficient amount of water is retained in the cleaning space, and the spray nozzle 9 of the high-pressure water spray nozzle unit 7 is placed on the water surface. In contrast, the height is set to be higher by a predetermined dimension H.

As shown in FIGS. 2 and 3, the injection nozzles 9 are provided in plurality, and are supplied with high pressure water from a water pressure pump 11 outside the polishing head 2 via a high pressure water pipe 10. It has become so. Here, the high-pressure water pipe 10 is inserted into the support member 6 through the disk 3 on the supply side. Further, the slurry outflow pipe 8 is supported through the disk 3 on the supply side, and is configured to be supplied with slurry of the abrasive material from a slurry pump 12 outside the polishing head 2.

Furthermore, water receivers 13 are arranged at the open ends on both sides of the cylinder 1, and all excess water in the cylinder 1 is collected into a recovery tank 14 via the water receivers 13.

A stirrer 15 is disposed in the recovery tank 14 to stir the recovered surplus water, that is, the water containing the abrasive material, to suspend the abrasive material and form a slurry. The formed slurry is supplied into the cylinder 1 again by the slurry pump 12 described above. Further, a concentration sensor 16 is provided in the middle of the slurry outflow pipe 8, and a signal from the concentration sensor 16 operates a control means (not shown) to control the abrasive material hopper 17 provided in the recovery dunk 14. It is designed to maintain a constant concentration by controlling and replenishing the abrasive material as appropriate.

By the way, as described above, since the slurry is configured to circulate between the cylinder 1 and the recovery tank 14,
When all the surplus water in the cylinder 1 is collected into the recovery tank 14, the high-pressure water injected from the high-pressure water injection nozzle unit 7 becomes surplus water in the recovery tank 14. In this embodiment, this surplus water is pumped out by a drain pump 19 through a filter 18 and discharged as clean water. Further, a backwash valve 20 is provided between the filter 18 and the drain pump 19, which sends pressure air to the filter 18 to perform element cleaning as appropriate.
8 can be prevented from clogging.

Furthermore, in this embodiment, first and second drive mechanisms that drive the polishing head 2 and a third drive mechanism that drives the cylinder 1 are provided. That is, the polishing head 2 is provided with a drive rod 24 extending from the center of the disk 3 on the supply side in the external axial direction, and the polishing head 2 is connected to the first drive mechanism 21 via this drive rod 24. By the driving force of
It is capable of linear movement in the axial direction, and is also capable of reciprocating rotation within a certain range by the driving force of the second drive mechanism 22. In this case, the grinding head 2 is provided with a guide rod 25 which extends from the center of the disk 4 on the overflow side symmetrically to the drive rod 24, and these rods 24,25 are arranged in the vicinity of the grinding head 2. A guide roller 26 is provided for guiding the polishing head 2 within the cylinder 1. Further, the cylinder 1 is supported on a third drive mechanism 23, and can be rotated to both sides by the operation of this drive mechanism 23.

The operation of this embodiment having the above configuration is as follows.

First, the cylinder 1 is supported at a predetermined position above the third drive mechanism 23, and in this state, the polishing head 2 is inserted into the cylinder 1 by the driving force of the first drive mechanism 21. Then, the two disks 3 and 4 of the polishing head 2 and the seal elastic body 5 form a cleaning space sandwiched between the two disks 3 and 4 within the cylinder 1.

In this state, the water pressure pump 11 is operated to inject high pressure water from the injection nozzle 9 of the high pressure water injection nozzle unit 7 via the high pressure water piping 10, and at the same time, the slurry pump 12
is operated, and the slurry flows out from the slurry outflow port 8a through the slurry outflow pipe 8. Then, the mixed water of high-pressure water and slurry accumulated in the cleaning space becomes an agitation jet, and due to the high water pressure and the action of the abrasive material contained in the slurry, the inner surface of the cylinder 1 is efficiently polished in a short time. can. The cleaning range in this case corresponds to the range contacted by the high-pressure jet water sprayed from the spray nozzle 9, as shown in FIG.

The first to third drive mechanisms 21 to 23 can move the cleaning head 2 in the axial direction, rotate it around the axis, and rotate the cylinder 1, so that the cleaning head 2 can be moved to an appropriate cleaning position. By performing the above-mentioned cleaning work while shifting the position, the entire inner surface of the target cylinder 1 can be efficiently cleaned in a short time.

Specifically, when removing oxidized scale from the inner surface of a shaft with a diameter of 120 mm and a length of 6000 mm, it took 140 to 200 hours per shaft in the conventional technology, but in this example, it took 140 to 200 hours. It has been confirmed that the cleaning work can be completed in about 1 to 4 hours, which is approximately 1/10th of the time.

In addition, surplus water from the grinding work overflows from the opening 4a provided in the disk 4 and is collected in the recovery tank 14, so the water in the recovery tank 14 is stirred by the agitator 15 to form a slurry. By forming the slurry and supplying the formed slurry to the polishing head 2, repeated polishing operations can be performed. In this case, not all of the slurry supplied to the polishing head 2 can be recovered, so the concentration of the abrasive gradually decreases as the polishing work is repeated. A concentration sensor 16 installed midway detects the concentration of the slurry, and when the concentration of the abrasive falls below a predetermined level, the abrasive hopper 17 provided in the collection tank 14 is controlled to stop the polishing. Since the material can be replenished appropriately, a constant concentration can be maintained.

Further, if the second drive mechanism 22 performs the cleaning operation while reciprocating the cleaning head 2 in small increments, a more effective stirring jet can be formed and the efficiency of the cleaning operation can be improved.

Note that the present invention is not limited to the above-mentioned embodiments, and the number of injection nozzles 9 in the high-pressure water injection nozzle unit 7 can be selected as appropriate, and the specifics of the first to third drive mechanisms can be selected as appropriate. The configuration can also be selected as appropriate. Furthermore, in the embodiment described above, excess water in the recovery tank 14 is removed from the filter 1.
8 with a drainage pump 19 and discharged as clean water. However, if this clean water is re-supplied to the Honjo pump 11, a water-saving effect can be obtained.

Further, the present invention is suitable for removing oxide scale on the shaft of a steam turbine in a power plant, but is not limited thereto, and can be similarly applied to various types of cylinders on which harmful foreign matter is likely to adhere or form on the inner surface. Similar excellent effects can be obtained.

[Effects of the Invention] As explained above, in the cylindrical inner surface polishing device of the present invention, a cleaning space is formed by the disk of the cleaning head and the sealing means, and high-pressure water is injected within this cleaning space. ,
By flowing out the slurry containing the abrasive material, high water pressure and the abrasive material can act synergistically, making it possible to reliably remove foreign matter from the inner surface of the cylinder in a much shorter working time than before. You can get the effect.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing an embodiment of the cylindrical inner surface grinding device according to the present invention, Fig. 2 is an axial cross-sectional view showing the grinding operation state of the device, and Fig. 3 is a sectional view perpendicular to the axis. FIG. DESCRIPTION OF SYMBOLS 1... Cylinder, 2... Grinding head, 3, 4... Disc, 4a... Opening, 5... Seal elastic body, 6...
Support member, 7... High pressure water injection nozzle unit, 8...
・Slurry outlet pipe, 8a...Slurry outlet, 9...
- Injection nozzle, 10... High pressure water piping, 11... Water pressure pump, 12... Slurry pump, 13... Water receiver, 14... Recovery tank, 15... Stirrer, 16.
...Concentration sensor, 17... Abrasive material hopper, 18...
Filter, 19... Drain pump, 20... Backflow valve,
21... First drive mechanism, 22... Second drive mechanism, 23... Third drive mechanism, 24... Drive rod,
25... Guide rod, 26... Guide roller.

Claims (1)

[Claims] A polishing head that is inserted into a cylinder and jets high-pressure water and at the same time flows out a slurry containing an abrasive material to polish the inner surface of the cylinder, and a high-pressure water generating means that generates high-pressure water. , a high-pressure water supply means for supplying the generated high-pressure water to the polishing head, a recovery tank for recovering excess water containing the abrasive material in the cylinder, and a stirring system for agitating the water containing the abrasive material in the recovery tank. A stirrer that suspends the abrasive material to form a slurry; a slurry supply means that supplies the formed slurry to the polishing head; a first drive mechanism that linearly moves the polishing head in the axial direction; and a polishing head. a second drive mechanism that rotates the cylinder to both sides about its axis, and a third drive mechanism that rotates the cylinder to both sides about its axis, and the polishing head is rotated at a constant interval. Two disks of the same diameter arranged in parallel with a gap and integrally supported, a sealing means for sealing between the outer periphery of each disk and the inner surface of the cylinder, and excess water overflow provided in at least one of the disks. A cylindrical inner surface grinding device characterized in that it has a high-pressure water injection means and a slurry outflow means supported by one of the disks and arranged such that the open end thereof is located between the two disks. Sweeping device.