JPS6239037B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for cleaning a pipeline for transporting powder or slurry, and in particular, uses an elastic pipe for all or a part of the transport pipe and cleans the elastic pipe in the circumferential direction. This invention relates to a cleaning method capable of destroying the adhered hardened material (hereinafter referred to as "scale") formed in the pipeline by the elastic damped vibration action of the elastic pipe after deformation, and preventing clogging in the pipeline. It is something.

Pneumatic transport means for powder and fluid transport means for slurry are widely used in various fields, and in order to transport powder and slurry at as uniform a pace as possible, hoppers, silos, and various other systems including these are used. Feeder mechanisms and pipelines have been developed. On the other hand, research has been conducted on the shape, particle size, moisture content, etc. of the powder side, and in particular, by improving the flow within the feeder mechanism, the bridge formation accidents that frequently occurred in the feeder mechanism have almost been resolved. ing.

However, depending on the atmosphere inside the equipment in the pipeline that connects and opens from the feeder mechanism to the destination equipment, the chemical properties of the powder in the pipeline (changes due to absorption of carbon dioxide such as hygroscopicity) and physical Powder properties (surface friction coefficient, adhesion, fluidity, etc.) change, and powder stagnates in the pipeline due to long-term operation, resulting in significant clogging due to stagnation, especially at bends. This has become a problem as it has become impossible to transport powder stably or quantitatively. This situation is the same in the case of slurry transportation, and as the operating time increases, various solid particles settle and accumulate in the pipeline, and then turn into solidified matter, which causes clogging and makes slurry transportation impossible. I was getting used to it.

Conventionally, the following two methods have been adopted as means for dealing with these problems. One method is to blow sand into the clogged part of the pipeline. However, this method not only causes damage within the pipeline and significantly shortens the life of the pipe, but also makes post-treatment of the sand difficult. Another method is to squeeze the pipe at a fixed position in the pipeline. However, this method has little effect; on the other hand, if the effect is to be increased, the number of throttling points must be increased, which complicates the operation, and transportation costs increase as the number of throttling devices increases.

The present invention has been developed in view of these circumstances, and its purpose is to improve the characteristics of the pipe without using complicated mechanical operations to cure the adherent hardened material formed in pipelines for transporting powder or slurry. The object of the present invention is to provide a cleaning method that effectively peels and breaks the pipe by utilizing the deformation of the pipe itself, thereby ensuring stable and quantitative transportation of powder and slurry.

However, the cleaning method of the present invention, which has achieved these objectives, uses an elastic pipe to form the part of the pipeline where scale is deposited, and a set of on-off valves to remove the scale over an appropriate length. The line is constructed so that it can be sealed, and a pressurizing or depressurizing pipe is connected to the appropriate position of the pipe to be sealed via a communication valve, and for cleaning, after closing the set of on-off valves, The pipe to be sealed is expanded or contracted in the circumferential direction by opening the communication valve and increasing or decreasing the pressure inside the pipe to be sealed, and after closing the communication valve, the pipe is opened by opening at least one of the opening/closing valves. The gist of this method is to induce a shock in the pipe to be sealed due to elastically damped vibration in the direction perpendicular to the axis, and to peel off and remove scale attached to the inside of the pipeline by the vibration action.

The configuration and effects of the present invention will be specifically explained below based on the drawings of the embodiments, but the embodiments below are merely representative examples, and may be implemented with appropriate modifications in keeping with the spirit of the preceding and following. This is also included within the technical scope of the present invention. Further, in the following embodiment, a representative explanation will be given of a powder transportation pipeline (hereinafter simply referred to as "pipeline").

FIG. 1 is a schematic explanatory diagram of the method of the present invention, in which 1 is a pipeline made of vinyl chloride, 2 and 3 are arranged before and after the pipeline 1 over an appropriate length so that the pipeline 1 can be sealed. This is a set of on-off valves. That is, the pipeline 1 between these on-off valves 2 and 3 becomes a sealed pipe 1'. Further, 4 is a pressurizing or depressurizing pipe (hereinafter referred to as "pressure changing pipe") connected to the on-off valve 2 side of the sealed pipe 1', and 5 is a communication valve interposed in the pressure changing pipe 4. Therefore, by opening the communication valve 5 and making the pressure transformation piping 4 and the sealed pipe 1' communicate with each other, the sealed pipe 1' is opened from the inlet side 4a of the pressure transformation piping 4.
The structure is such that pressurized fluid can be injected into the sealed pipe 1' or the pressure inside the sealed pipe 1' can be reduced.

When actually performing a cleaning operation with such a configuration, the following procedure is followed. That is, after a certain period of time has elapsed after the start of powder pneumatic transportation through the pipeline 1, the transportation is stopped and the on-off valves 2 and 3 are closed. Next, after opening the communication valve 5 to make the pressure transformation piping 4 and the sealed pipe 1' communicate with each other, high pressure air or high pressure water is injected from the inlet side 4a for a predetermined period of time until a predetermined pressure is reached. ' is expanded in the circumferential direction as shown in FIG. At this time, many cracks occur in the scale and the scale is cut and divided. This is due to the difference in mechanical properties due to the fact that the tube to be sealed 1' has an elastic bulk structure, whereas the scale has a film-like hardened structure. Note that the degree of pressurization load can be freely set depending on the thickness of the scale and the condition of the scale.

After increasing the pressure inside the pipeline 1 to a predetermined pressure and expanding the diameter, the communication valve 5 is closed and the on-off valve 3
is opened to allow communication between the inside of the sealed pipe 1' and the pipeline 1. As a result, the pressure inside the sealed pipe 1' decreases rapidly and becomes equal to the pressure inside the pipeline 1. That is, since the tube to be sealed 1', which is an elastic body, is instantly elastically deformed from the direction of expansion and expansion to the direction of contraction and contraction,
As shown by the arrow in FIG. 3, elastically damped vibration occurs in the direction perpendicular to the axis. Since this vibration action acts over the entire tube to be sealed 1', all the scale within the tube to be sealed 1' is easily peeled off and falls. After that, if the sealed pipe 1' comes to rest as shown in Fig. 1, the on-off valve 2
to resume pneumatic transport on Pipeline 1.
In this way, the scale that has peeled off and fallen within the sealed tube 1' can be easily transported and removed by the air flow. Note that when connecting the sealed pipe 1' in a pressurized state to the pipeline 1 in a normal pressure state, the on-off valve 2 may be opened first, or the on-off valves 2 and 3 may be opened first.
It is also possible to open both at the same time.

On the other hand, the same effect can be expected even if a decompression operation is performed instead of the pressurization operation as described above. That is, when using the pressure reduction operation, after closing the on-off valves 2 and 3 as in the case of the above-mentioned pressurization operation,
The communication valve 5 closes the sealed pipe 1' as shown in FIG.
When the inside of the tube 1' is previously depressurized and the on-off valves 2 and/or 3 are opened, the entire sealed tube 1' undergoes elastically damped vibrations, as in the case of pressurization. the result,
All the scale within the tube to be sealed 1' is easily peeled off and falls. The degree of pressure reduction load can also be freely set depending on the thickness of the scale and the condition of the scale.

Further, the timing of applying the pressurization and depressurization operations as described above is arbitrary, regardless of whether it is regular or irregular. Also, on-off valves 2 and 3
The communication valve 5 and the communication valve 5 can also be connected to a control device and set to be operated in conjunction with a certain electrical signal, which is within the scope of ordinary electrical instrumentation design.

Further, in the above embodiment, vinyl chloride pipes were used for the entire pipeline 1, but of course it is also possible to use them for only a part of the pipeline 1. This is particularly effective at corners, such as in curved sections of pipelines. Further, the pipeline is not limited to a pipe made of vinyl chloride, but may be made of synthetic rubber or the like, and in short, it may be made of an elastic pipe.

The method of the present invention is constructed as described above, but the point is that the elasticity of the pipe is used to apply self-deforming force to the pipe itself, and the scale in the pipeline is easily self-forced to destroy, so it is complicated. This eliminates the need for scale removal operations using expensive mechanical means, and allows stable and quantitative transportation of powder and slurry to be carried out reliably and smoothly. Therefore, the cleaning method of the present invention removes HCl from the incinerator exhaust gas.
It is extremely useful as a cleaning means for slaked lime injection pipelines for dry removal of slaked lime, pipelines for transporting powders for gas treatment or water treatment, and pipelines for transporting various slurries.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of the method of the present invention, and FIGS. 2 to 4 are explanatory diagrams of the cleaning operation procedure. 1...Pipeline, 1'...Pipe to be sealed, 2, 3...
Opening/closing valve, 4...Pipe for pressurization or depressurization, 5...Communication valve.

Claims (1)

[Claims] 1. A method for cleaning a pipeline for transporting powder or slurry, in which the entire or main part of the pipeline is formed of an elastic pipe, and the line can be closed over an appropriate length with a set of on-off valves. A method for cleaning a pipeline, characterized in that during cleaning, the pressure inside the sealed pipe is increased or decreased by opening and closing the set of on-off valves, thereby inducing elastic damped vibrations.