JPH0121032Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to an improvement of an abrasive supply device installed in a device for cleaning the inner wall of a pipe, and uses a mixed fluid of an abrasive and a compressed fluid to polish the inner wall surface of the pipe. It is mainly used for cleaning.

(Conventional technology) A method for rehabilitating buried water pipes, buried gas pipes, etc. involves flowing a mixed fluid of abrasive material and compressed air into the pipes at high speed to grind away scale, etc. on the inner walls of the pipes. is widely used (Japanese Unexamined Patent Application Publication No. 1983-1999)
41852 etc.).

In the method, as shown in FIG. 4, abrasive material (silica sand, etc.) 2 stored in a tank 1 is flowed into a mixing ejector 4 via an abrasive material valve 3, and a fluid supply device for conveyance such as a compressor is used. After mixing with the compressed air A from 6, the mixed fluid B of air and abrasive material is ejected into the tube C to be treated.
Further, compressed air A' is supplied into the tank 1 via a regulator 5, and the inside of the tank 1 is pressurized to an appropriate pressure.

Incidentally, the start and stop of supply of the abrasive material 2 to the mixing ejector 4 are all controlled by opening and closing of the abrasive material valve 3, and the flow rate of the abrasive material 2 supplied into the air flow A is , is controlled by adjusting the opening degree of the abrasive valve 3. That is, the pressure inside the tank 1 is maintained at a substantially constant value, and the opening degree of the abrasive material valve 3 is adjusted to control the outflow amount of the abrasive material 2.

However, in the conventional abrasive supply device configured as described above, the abrasive valve 3 is extremely damaged due to wear, requiring a lot of effort to repair, and the abrasive is removed during the grinding process. When it becomes necessary to stop the supply of the abrasive, the abrasive often leaks and the outflow of the abrasive cannot be completely stopped.

That is, normally, after the polishing work on the inner wall of the pipe is completed, the abrasive valve 3 is closed to stop the supply of the sand jet flow into the pipe to be treated C, and only the air flow A is supplied to clean the inside of the pipe. Abrasive material often leaks due to wear and tear on the valve body, valve seat, etc. of the abrasive valve 3, making it impossible to smoothly switch from abrasive work to pipe cleaning work, resulting in a decrease in work efficiency. There's a problem.

Furthermore, due to wear and tear on the regulating valve 3, errors are likely to occur in the flow rate control of the abrasive material, resulting in poor grinding of the tube C to be treated, clogging during grinding, or deep grinding of the inner wall surface of the tube. .

(Problems to be Solved by the Invention) The present invention solves the above-mentioned problems in conventional abrasive supply devices of this type, that is, when it is necessary to stop the supply of abrasive in the middle of the polishing operation. Leaks of abrasive material may occur, making it time-consuming to switch from grinding work to cleaning work, resulting in a decrease in work efficiency;
The abrasive valve is severely damaged and requires a lot of effort to repair, the abrasive flow rate control becomes inaccurate, the efficiency of grinding the pipe to be processed decreases, and it takes time to calibrate the settings of the flow rate adjustment valve, etc. This abrasive is intended to solve the problem, and is capable of stopping and starting the supply of abrasive without operating the abrasive valve 3, and also allows the desired abrasive flow rate to be easily obtained. A supply device is provided.

(Means for Solving the Problems) The present invention communicates the outlet of the abrasive tank and the suction port of the mixing ejector with an abrasive flow rate adjustment valve, and also allows the fluid from the conveying fluid supply device to communicate with the outlet of the abrasive tank and the suction port of the mixing ejector. Switchably branching the flow into two-way pipes, connecting one pipe to the abrasive tank and the inlet of the mixing ejector, and the other pipe to the outlet of the mixing ejector,
The basic configuration of the invention is to control the outflow of the abrasive material from the abrasive material tank by switching the flow direction of the fluid.

(Function) Switching the flow direction of the fluid from the conveying fluid supply device, stopping the supply of fluid to the inlet of the mixing ejector and the inlet of the tank, and supplying the fluid to the outlet of the mixing ejector causes the inside of the tank and the mixing ejector to be stopped. The internal pressure becomes approximately the same, and the abrasive material stops flowing from the tank into the mixing ejector.

Fluid is then directly supplied into the tube to be treated from the conveying fluid supply device, and the inside of the tube is cleaned.

(Embodiment) FIG. 1 is a piping system diagram of an abrasive supply device according to a first embodiment of the present invention, and the same reference numerals are used for the same parts as in FIG. 4.

An abrasive material tank 1 stores an abrasive material 2 such as silica sand, and an outlet 1a of the tank 1 is connected to a mixing ejector 4 by interposing an abrasive material flow rate adjustment valve 7 that only adjusts the flow rate of the abrasive material. It communicates with the suction port 4a.

The downstream side of the connection port R to the transport fluid supply device 6 is branched into a pipe line 8 and a pipe line 9, and the pipe line 8 is provided above the side wall of the tank 1 via a valve 10 and a regulator 5. It is connected to the entrance 1b.

Further, a pipe line 12 is branched from the outlet 10b of the valve 10 of the pipe line 8, and the pipe line 12 is connected to the fluid inlet 4b of the mixing ejector 4.

On the other hand, the other pipe line 9 is connected to the outlet 4c side of the mixing ejector 4 with a valve 11 interposed therebetween.

Next, the operation of the abrasive supply device according to the present invention will be explained.

First, when cleaning the pipe to be treated, the flow rate regulating valve 7 is set to a predetermined opening position, and the regulator 5 is also adjusted to a predetermined pressure. Although the regulator 5 is used in this embodiment, it goes without saying that the regulator 5 may be omitted. Also, while opening the valves 14, 15, and 10,
Close valve 11.

Thereafter, a transport fluid (compressed air) A at a predetermined pressure (2 to 10 kg/cm ² ) is supplied from the transport fluid supply device 6 (compressor device). As a result, the inside of the tank 1 is pressurized, and the valve 10 and the pipe line 1 are
Compressed air A is supplied into the mixing ejector 4 through the mixing ejector 2, and a suction force is generated within the ejector 4. As a result, the abrasive material 2 in the tank 1 flows down into the mixing ejector 4 through the regulating valve 6, and after being mixed with the compressed air A, the mixed fluid B formed is transferred to the outlet 4C.
It is ejected into the tube C to be treated.

Further, when the supply of the abrasive material 2 is stopped and only the compressed fluid A is supplied to the tube to be treated C, the valve 10 is closed and the valve 11 is opened. As a result, the pressures in the mixing ejector 4 and the tank 1 became approximately the same, and the outflow of the abrasive material 2 from the tank 1 was stopped, and the abrasive material 2 was accumulated on the bottom wall surface of the mixing ejector 4, as shown in FIG. In this state, the outflow of the abrasive material 2 is stopped. still,
When both valves 10 and 11 are closed, the abrasive material 2
and compressed fluid A stop flowing out.

FIG. 3 is a system diagram of an abrasive supply device according to a second embodiment of the present invention, in which valve 10 and valve 11 of FIG.
The point is that one switching valve 16 is used instead of
The only difference is that a replaceable orifice 17 is used in place of the abrasive flow rate regulating valve 6.

That is, by operating the handle of the switching valve 16, the communication between the port 16a and the port 16b (port 16a
and port 16c), communication between port 16a and port 16c (port 16a and port 16b
) and port 16a and both ports 16
Three types of operations are performed, including the interruption between b and 16c, and the same operation as in the first embodiment is obtained.

Further, the orifice 17 is replaced depending on the required flow rate of the abrasive material 2, and a predetermined amount of the abrasive material 2 is supplied to the mixing ejector 4.

(Effect of the invention) In the present invention, the fluid from the conveying fluid supply device can be switched in two directions, and one fluid is supplied to the inlet side of the abrasive tank 1 and the mixing ejector 4, while the other fluid is supplied to the inlet side of the abrasive tank 1 and the mixing ejector 4. Since the structure is such that the abrasive material is supplied to the outlet side of the mixing ejector 4, the abrasive material flow rate adjustment valve 7 installed in the pipe between the tank 1 and the suction port of the mixing ejector 4 can be supplied without operating the abrasive material flow rate regulating valve 7. By switching the fluid supply path from the fluid supply device, the supply of abrasive material can be completely stopped. As a result, cleaning inside the pipeline was completed,
Even when cleaning the inside of the pipeline with a conveying fluid, there is no need to worry about the leakage of abrasive material that takes time and effort in the cleaning operation, which was the case in the past. Switching to can be done extremely smoothly.

In addition, the flow rate regulating valve 7 is thereby configured to control the abrasive material 2.
Since there is no need to completely stop the flow of water, there is no need to replace it as often as before, making it possible to significantly reduce repair costs.

As mentioned above, the present invention has excellent practical effects.

[Brief explanation of the drawing]

FIG. 1 is a system diagram of an abrasive supply device according to a first embodiment of the present invention. FIG. 2 is an explanatory diagram showing a state in which the outflow of abrasive material is stopped in the present invention. FIG. 3 is a system diagram of an abrasive supply device according to a second embodiment of the present invention. FIG. 4 is a system diagram of a conventional abrasive supply device. DESCRIPTION OF SYMBOLS 1... Abrasive tank, 2... Abrasive material, 4... Mixing ejector, 6... Conveying fluid supply device, 7...
... Abrasive material flow rate adjustment valve, 8, 9 ... Pipe line, 10, 1
1... Valve, 12, 13... Pipe line, 16... Switching valve, 17... Orifice.

Claims (1)

[Scope of utility model registration request] Outlet 1a of abrasive tank 1 and mixing ejector 4
The suction port 4a of the abrasive material is communicated with the abrasive material flow rate regulating valve 7 through an interposed abrasive material flow rate adjustment valve 7, and the fluid A is distributed from the conveying fluid supply device 6 to either of the two-way pipe lines 8 and 9 in a switchable manner. One pipe line 8 is connected to the inlet 1 of the abrasive tank 1.
b to the inlet 4b of the mixing ejector 4, and the other pipe 9 to the outlet 4c of the mixing ejector 4, and the flow direction of the fluid A is directed from the pipe 8 side to the pipe 9.
An abrasive supply device for cleaning an inner wall of a pipe, characterized in that the outflow of abrasive 2 from an abrasive tank 1 is blocked by switching to the side.