JPS62136283A - Method of washing piping - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Technical field of invention 1 The present invention relates to a method for cleaning piping.

[Technical background of the invention and its problems] When cleaning a piping system, there are cases where the start and end points of the piping to be cleaned are far apart and the piping route is installed in a difficult location that is difficult for people to access. . Even in such cases, if the cleaning agent is cheap and available in large quantities and the cleaning waste can be easily discharged, it is recommended to pour the cleaning agent into one end of the pipe to be cleaned and discharge the cleaning waste from the other end of the pipe to be cleaned. However, the cleaning agent is currently expensive in most cases, and cleaning waste liquid cannot be easily disposed of due to external factors such as environmental pollution.

Therefore, in cleaning the piping system as described above, a return piping is further provided in the piping to be cleaned to form a circulation line, and particles (such as cation ion exchange resin particles, polyester particles, chikunya particles, zirconia particles, etc.) are placed in this circulation line. A method of cleaning the piping to be cleaned is carried out by alternately flowing a chemical liquid (for example, an inorganic chemical liquid such as a mineral acid, an organic chemical liquid such as an organic acid or a surfactant, etc.). However, in such a cleaning method, when the scale particles attached to the inner surface of the pipe are removed, the inner surface of the pipe is also polished, which causes damage to the base material of the pipe.

In addition, if the piping runs through shielding or hot cells, such as equipment using radioactive isotopes or nuclear power equipment, and it is difficult to install return piping even if you want to install it, for example, in a contaminated area or with insufficient shielding. In some cases, such as areas, return piping cannot be installed. Furthermore, such facilities require measures to prevent leaks in case of emergency, and even when radioactive fluid is transported through pipes as part of temporary construction work, considerable security measures are required, resulting in high costs. In addition, permissions are required when running radioactive waste liquid piping in areas where radioactivity is not normally used, which poses the problem of long construction times.

Therefore, it is desired to develop a method for cleaning piping that does not damage the base material of the piping, reduces the amount of cleaning agent used, reduces the amount of waste liquid associated with cleaning, and is inexpensive and has a simple configuration. was.

[Object of the Invention] The present invention has been made in consideration of the above-mentioned circumstances, and its purpose is to provide a simple and effective method for cleaning piping systems even when a circulating cleaning method or a mechanical cleaning method for piping cannot be used. An object of the present invention is to provide a method for cleaning piping that has a cleaning effect.

[Summary of the Invention] In order to achieve the above object, the present invention connects cleaning devices to both ends of a pipe to be cleaned, and causes cleaning fluid stagnant in one of the cleaning devices to flow in from one end of the pipe. After flowing out from the other end of the piping and receiving it in the other cleaning device connected to the other end of the piping, the process of sending the cleaning fluid back through the piping is repeated one or more times to clean the inside of the piping. The present invention relates to a method for cleaning piping.

A cleaning agent or a fluid consisting of a cleaning agent and particles is used as the cleaning fluid, and a skid or a catching loader is used as the cleaning device.

[Embodiments of the invention] Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a schematic system diagram of an embodiment of the present invention.
One skid 2A at each end of the pipe 1 to be cleaned,
Install 2B. These skids 2A, 2B are respectively cleaning agent tanks 3A, 3B1 pumps 4A, 4B, level detectors 5A, 5B, liquid sending valves 6A, 6B, liquid receiving valves 7A, 7B.
and connecting pipes 8A and 8B. Tank 3 of skid 2A installed at one end of pipe 1 to be cleaned
Fill A with enough cleaning agent to fill the pipe 1 to be cleaned and leave some residual m in the tank 3A. This cleaning agent is sent into the pipe 1 to be cleaned by the pump 4A via the liquid sending valve 6A, and flows into the cleaning agent tank 3B of the skid 2B installed at the other end of the pipe 1 to be cleaned. And cleaning agent tank 3
When A is empty or has decreased to a specified level, stop the pump 4A, and then pump the cleaning agent present in the cleaning agent tank 3B on the opposite side to the pipe 1 to be cleaned via the liquid sending valve 6B.
and flows into the cleaning agent tank 3A of the skid 2A. Further, a level detector 5A detects the level of the cleaning agent in the cleaning agent tanks 3A and 3B.

The pumps 4A and 4B are automatically turned on and off by the pump 5B, and the pumps 4A and 4B are configured to be activated alternately. For example, for four pipes with a length of 250 m, the required flow rate is approximately 2
m, plus the number 101 required to fill the bottom of the tank
The minimum amount of cleaning agent required is the amount of cleaning agent added. Therefore, the effective amount of cleaning agent is about 2.5 m. In addition, the faster the flow rate of the cleaning agent flowing inside the pipe 1 to be cleaned, the more effective the cleaning will be, but in the case of chemical cleaning, the flow rate is several tens of cm/
Since a flow rate of 380 or more is sufficient, pump 8
A suspension of 15 m/h or more is sufficient.

FIG. 2 is a schematic system diagram of another embodiment of the present invention.

In this embodiment, a chemical cleaning method is applied, and as shown in the figure, one particle catching loader IOA, 10B is installed at each end of the pipe 1 to be cleaned. This catching loader 10A.

10B is connected to cleaning agent tanks 11Δ, 11B and pumps 12A, 12B via connecting pipes 17A, 17B, respectively.
It is connected to the. Also, flowmeters 13A, 13B and pressure gauge 14A for measuring flow rate and pressure during liquid feeding,
14B are installed in connecting pipes 17A and 17B on the outlet side of the cleaning agent tanks 11A and 11B. In addition, 15A, 1
5B is a liquid receiving valve, and 16A and 16B are liquid sending valves.

FIG. 3 is a longitudinal sectional view of the catching loader 10A,
As shown in the figure, the lower part of the container body 18A of the catching loader 10A has a conical shape, and the lowermost opening 19A is connected to the pipe 1 to be cleaned via a valve 9A (see Figure 2). There is. Further, a thin mesh strainer 2OA of 0.5n+m or less is inserted from the upper part of the container body 18A, and the upper flange portion 21A is engaged with the upper 7 flange of the container body 18A by a one-touch clamp 22A. Furthermore, the upper opening 23A of the strainer 20Δ is connected to the cleaning agent tank 1 through the connecting pipe 17A.
Connected to 1A. Further, for example, granular cation exchange resin particles 24 are placed 101 in the kitchen grooder container main body 18A, and the lower valve 9A is closed.

Pour 2.5III of the chemical solution into the cleaning agent tank 11△,
Open the valve 16A, open the valve 15A, start the pump 12A, and circulate the chemical solution. Next, when the valve 9B and the valve 15B are opened, and the valve 15A is further tightened and the valve 9A is opened, the particles are pushed out with the chemical solution into the pipe 1 to be cleaned and collected in the catching loader 10B on the opposite side. is collected in the cleaning agent tank 11B.

As described above, in this embodiment, two catching loaders 10A are used to catch particles each time the cleaning fluid is used for alternate cleaning.

It is configured to make a round trip between 10B and 10B.

In addition, by flowing particles that are not attacked by chemical cleaning agents at a speed of 1 m/sec or more (when flowing particles, it is better to use a faster flow rate than in the above example), the particles will rub against the wall surface, so simply apply the chemical cleaning agent. It is possible to apply greater shear stress to the inner wall than by flowing, thereby promoting scale peeling and dissolution. For example, chemical cleaning agent amount 250+, pump lift 2
0m, flow rate 5m”/h, connection piping flexible hose 4
0A.

Valve head ball valve, catching loader A 40A steel pipe is cleaned with a cleaning agent and particles at a particle amount of 101. The time for which the cleaning solution is poured varies depending on the type of chemical, but sufficient cleaning can be achieved in 8 to 24 hours.

At this time, the maximum cleaning flow rate is 5Il13/h, but if the piping length is long, the pressure loss becomes large and it decreases to about 1+n3/h.

[Effects of the Invention] As explained above, according to the present invention, if both ends of the piping to be cleaned are separated with appropriate cells or tanks, and the cleaning skids are connected together for cleaning, it is possible to improve the efficiency from the viewpoint of approval and approval, as well as construction period and cost. will also be advantageous.

In addition, the amount of cleaning agent used may be the same as the amount of cleaning agent used for holding the pipes and adding some measures to prevent cavitation of the pump.Especially in nuclear couplants, the amount of radioactive waste generated is small and there is no waste liquid. Good.

Furthermore, since the cleaning liquid is flowed periodically, strong shear stress is applied to the piping wall at the beginning of the flow, causing scale to peel off, which is advantageous in removing scale. Furthermore, since there is no need to install or remove return piping, the work area is narrowly limited, which is advantageous for construction management when cleaning nuclear power related facilities.

In addition, if there is an outbound pipe as in the conventional method, the number of storage devices increases and the warehouse storage cost increases, but the present invention uses only two relatively compact skids and connecting pipes, so it does not take up storage space. It has excellent effects such as being advantageous for storage.

[Brief explanation of drawings]

FIG. 1 is a schematic system diagram of one embodiment of the present invention, FIG. 2 is a schematic system diagram of another embodiment of the invention, and FIG. 3 is a longitudinal sectional view of the catching loader of FIG. 2. 1... Piping to be cleaned, 2A, 2B... Skid 3△
, 38.11A, 11B...Cleaning agent tank 4A, 4B
, 12A, 12B... Pump 5A, 5B... Level detector 10A, IOB... Catching loader (8733)
Representative Patent Attorney Akira Inokosha (and 1 other person) 2nd I! f 23A 3rd area

Claims (3)

[Claims] (1) A cleaning device is connected to both ends of the piping to be cleaned, and the cleaning fluid stagnant in one cleaning device flows in from one end of the piping and flows out from the other end of the piping. A method for cleaning piping, characterized in that the inside of the piping is cleaned by repeating the process of sending the cleaning fluid back through the piping once or more after the cleaning fluid is received by the other cleaning device connected to the piping. (2) The method for cleaning piping according to claim 1, wherein the cleaning fluid is a cleaning agent or a fluid consisting of a cleaning agent and particles. (3) The method for cleaning piping according to claim 1, wherein the cleaning device is a skid or a catching loader.