JP6480981B2 - Pipeline cleaning device - Google Patents

Description

  The present invention relates to a pipe line cleaning device for cleaning the inside of a pipe line through which a liquid flows by gas-liquid two-phase flow.

When cleaning the inside of a pipeline through which a liquid flows, the use of a gas-liquid two-phase flow in which air is mixed with a cleaning liquid is used in a variety of situations, and is well known (for example, used in a coating apparatus) (See Patent Document 1).
The cleaning device described in Patent Document 1 is provided with a branch portion upstream from a water tank that stores water used as a diluent for a paint, and an air supply source and a cleaning water supply source are branched from the branch portion. Are connected. And at the time of washing | cleaning, the gas-liquid two-phase flow generated with the air supply source and the washing water supply source is made to flow into an upstream pipe line from a branch part by switching the valve provided in the branch part.

  Some cleaning apparatuses that use this type of gas-liquid two-phase flow use air that is reduced to microbubbles. A cleaning device that uses microbubbles draws dirt and the like with a negative potential charged by the microbubbles, and pushes the dirt together with the microbubbles on the drainage flow, or ultrasonically when the microbubbles burst. It mainly uses the action of peeling off dirt adhering to the road inner surface.

  However, these effects by the microbubbles are hardly effective when the piping distance becomes long, and in some cases, the cleaning cannot be performed depending on the mass and size of dirt that can be cleaned, adhesion (force), and the like.

Japanese Patent Laid-Open No. 2002-210396

Although the cleaning apparatus described in Patent Document 1 cannot be determined because there is no specific place for the microbubble generator in the document, it is presumed that the air used is not a microbubble.
However, in this cleaning device, since the air supply source and the cleaning water supply source are arranged in the middle of the piping, it is impossible to perform cleaning over all the piping paths (upstream side of the branch portion). .

Therefore, when painting is resumed after cleaning, impurities (such as floating dust and paint debris) remaining in the paint tanks, water tanks, and these supply pumps, such as pipes that have not been cleaned, remain. There is a possibility of mixing with the paint, and as a result, there is a risk of deteriorating the painted surface.
For this reason, it is necessary to devise a system that minimizes the contamination of impurities such as dust and solids by arranging the piping so that all liquids (paints, etc.) that have been washed away from the pipeline during cleaning are discarded. A circulation path including a tank or water tank cannot be configured). From this, it is surmised that the effect of “not generating wasteful paint” claimed to be achieved in Patent Document 1 is not satisfactory in all implementation environments.

  The present invention has been made in view of the above circumstances, and provides a pipeline cleaning apparatus that can reliably remove impurities such as dust and solids contained in a flowing liquid (paint, etc.) with a simple structure. For the purpose.

In order to achieve the above object, the present invention has taken the following measures.
That is, the pipeline cleaning apparatus according to the present invention is a pipeline cleaning apparatus provided for pipeline equipment for sending the circulating liquid stored in a storage tank to a liquid feeding pipe by a pump, and takes in air outside the reservoir of the circulating liquid. An air supply pipe in which an air discharge part is arranged during storage of the circulating fluid and air taken in from the air intake part of the air supply pipe is converted into a bubble or air flow of a millimeter size or more from the air discharge part. An air supply device that discharges the air, and the air discharge portion of the air supply pipe is air discharged from the air supply pipe with respect to a suction end of the liquid supply pipe provided toward the inside of the storage tank Are arranged close to each other within a range in which suction is possible, and when the pump and the air supply device are operated, the liquid flowing in the liquid feeding pipe is formed into a gas-liquid two-phase flow containing air bubbles or air bubbles of a millimeter size or more. Turbulent Wherein the washing liquid feed pipe.

When the suction end of the liquid feeding pipe is disposed facing downward, the air discharge portion of the air feeding pipe is coaxial with the suction end downward and upward with respect to the suction end of the liquid feeding pipe. It is preferable that they are arranged in the above.
The liquid supply pipe is formed with a piping path including the storage tank to generate a circulating flow, and the return end of the liquid supply pipe for returning the circulating liquid to the storage tank receives the pump pressure of the pump. The filter medium may be arranged in such a manner that it is pressure-cut so that there is no pressure.

The liquid feeding pipe has a blow pipe that switches the return pipe to guide the circulation flow to the return end and supplies the circulating liquid to the outside of the storage tank, and the filtering material is attached to the tip of the blow pipe. or equal to one having a mouth portion of the bore to allow insertion even a discharge pipe provided.
The liquid feeding pipe can be implemented as supplying paint to a spray gun.

  The pipeline cleaning apparatus according to the present invention can reliably remove impurities such as dust and solids contained in the flowing liquid (such as paint) with a simple structure.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic which showed 1st Embodiment of the pipe-line washing apparatus which concerns on this invention. It is the expanded side view which showed the connection relation of an air supply pipe and a liquid supply pipe in the principal part cross section. It is the schematic which showed 2nd Embodiment of the pipe-line washing apparatus which concerns on this invention. (A) is a photograph showing about 0.6 mm in size collected with a filter material after washing and a poorly painted surface resulting therefrom. (B) is about 0.3 mm in size collected with a filter material after washing. (C) is a photograph showing the state of the filter medium after washing for a predetermined time.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 and 2 show a first embodiment of a pipe cleaning device 1 according to the present invention. The pipe cleaning device 1 is configured to supply a circulating liquid 3 stored in a storage tank 2 by a pump 4 with a liquid feeding pipe 5 (a suction pipe 6,
(Return tube 7 and the one configured to have a blow-out tube 8 are illustrated) For the pipe line equipment 10 piped to be sent out to the pipe, it is attached to the detachable structure for each cleaning, Alternatively, it can be fixedly provided.

In the first embodiment, the pipe line facility 10 exemplifies a case where it is configured as a [coating apparatus] by attaching a spray gun 11 for coating to the tip of a blowing pipe 8 provided in the liquid feeding pipe 5. It is.
That is, by operating the pump 4, the flowing liquid 3 is supplied from the suction pipe 6 to the blowout pipe 8 to be ejected from the spray gun 11, or the supply to the blowout pipe 8 is switched to the return pipe 7. The circulating fluid 3 can be circulated between the pump 4, the return pipe 7, and the storage tank 2.

Further, by directing the spray gun 11 toward the storage tank 2, the circulating liquid 3 can be circulated between the suction pipe 6, the pump 4, the blowout pipe 8, the spray gun 11, and the storage tank 2.
The storage tank 2 is a [paint tank] using the circulating liquid 3 as a paint, a [diluent tank] using the circulating liquid 3 as a diluent for paint, or the circulating liquid 3 as a cleaning liquid [ Cleaning solution tank].

In addition, since the paint may be an organic paint or an aqueous paint, a thinner organic solvent or an inorganic solvent such as water can be selected for the diluent. The situation regarding the possibility of such replacement is the same for the cleaning liquid.
As is apparent from FIG. 1, the pipe cleaning device 1 according to the present invention includes an air supply pipe 16 and an air supply machine 17.

The air supply pipe 16 is provided with an air intake portion 16a outside the reservoir of the circulating fluid 3 (for example, above the reservoir 2), and discharges air while the circulating fluid 3 is being stored (below the fluid level of the circulating fluid 3 in the reservoir 2). A portion 16b is provided and piped so as to communicate between them.
Thereby, the air discharged from the air discharge part 16b is mixed with the circulating fluid 3 sucked up from the suction end 6a (the lower end of the suction tube 6) of the liquid feeding pipe 5 (while producing a gas-liquid two-phase flow). The liquid is supplied into the liquid feeding pipe 5.

  Between the air discharge part 16b of the air supply pipe | tube 16 and the suction end 6a of the liquid supply pipe | tube 5, the clearance gap by making it mutually separate is formed, or the surrounding wall of the air discharge part 16b and the suction end 6a instead of not separating. It is necessary to form an introduction part for the flowing liquid 3 by forming a through hole (not shown). Structurally, it is easiest to separate the air discharge portion 16b and the suction end 6a.

Regardless of which structure is employed, the air discharge portion 16b is brought close to the suction end 6a to such an extent that the discharged air can be sucked into the suction end 6a of the liquid delivery pipe 5.
However, the specific distance about how close these air discharge part 16b and the suction end 6a are made is not specifically limited. In some cases, the distance can be adjustable.

In this 1st Embodiment, as shown in FIG. 2, it is in the coaxial position which becomes further lower with respect to the suction end 6a of the liquid feeding pipe 5 (suction pipe 6) arrange | positioned toward the downward direction in the tank of the storage tank 2. As shown in FIG. The air discharge part 16b of the air supply pipe 16 is arranged so as to face upward.
However, the coaxial arrangement of the air discharge portion 16b and the suction end 6a is one of the optimum examples and is not necessarily limited. Accordingly, even when the axes are shifted from each other or when an inclination angle is generated between the axes, the air discharged from the air discharge portion 16b can be sucked into the suction end 6a of the liquid feeding pipe 5. If there is, it is within the allowable range.

  In addition, in the first embodiment, the air discharge portion 16b is arranged so as to be surely sucked into the suction end 6a while appropriately limiting or preventing the blown-out air from escaping outward in the circumferential direction. It is formed in a funnel shape with an enlarged opening. On the other hand, the suction end 6a is formed in an umbrella (cone) shape whose opening is enlarged toward the lower side in order to easily take in the air blown out from the air discharge portion 16b.

Thus, the air discharge part 16b is made into a funnel shape, the suction end 6a is made into an umbrella shape, and facing each other, an annular (ring-shaped) opening is generated between the two. Therefore, when the position of the air discharge portion 16b and the suction end 6a is adjusted so as to be close to and away from each other in the axial direction, the opening degree of the opening generated between the air discharge portion 16b and the suction end 6a is simply a change in the axial distance. In addition, the outer diameter and inner diameter of the annular opening both change, leading to the advantage that fine adjustment is possible.

In particular, the shape of the umbrella used for the suction end 6a induces a temporary retention of air under the umbrella, so that the gas-liquid two-phase flow flowing into the liquid feeding pipe 5 has a constant or indefinite rhythm. In addition to creating a so-called “turbulent flow” that causes turbulence in the flow, this turbulent flow is also extremely useful in making it a special one that sometimes mixes strong impact force and stirring force. is there.
In the first embodiment, the funnel shape of the air discharge portion 16b is larger than the umbrella shape of the suction end 6a. Conversely, the umbrella shape of the suction end 6a is larger than the funnel shape of the air discharge portion 16b. Therefore, the suction end 6a may take up everything on the air discharge portion 16b under the umbrella.

The air supply machine 17 is for generating a forced air flow from the air intake part 16a to the air discharge part 16b of the air supply pipe 16, and specifically, a blower (fan type or blower type). Or a compressor (compressor) is used.
Whether the air supply unit 17 is a blower or a compressor depends on whether the air discharged from the air discharge part 16b of the air supply pipe 16 is a bubble or airflow of a millimeter size or larger (not a microbubble such as a microbubble). The selection should be made based on the point of the item.

  Note that the air blown from the air discharge portion 16b of the air supply pipe 16 in response to the supply pressure from the air supply machine 17 is mixed with the circulating liquid 3 in the liquid supply pipe 5 as described above. The circulating fluid 3 receives the pump suction pressure of the pump 4. Therefore, the pressure relationship between the air supply pressure by the air supply machine 17 and the pump suction pressure by the pump 4 has a considerable influence on the amount of air that is entrained in the circulating liquid 3.

According to the experiments by the present inventors, when the air supply pressure of the air supply machine 17 is 0.1 MPa and the pump suction pressure of the pump 4 is 0.4 MPa, the amount of air caught in the circulating fluid 3 becomes moderate, It has been confirmed that this leads to a suitable cleaning result.
However, numerical fluctuations are considered depending on the pipe diameter and pipe distance of the liquid supply pipe 5 and the air supply pipe 16, the pipe resistance resulting from them, the type of the circulating fluid 3, the fluid temperature and the air temperature, etc. A certain range is allowed for the pressure relationship between the air supply pressure by the machine 17 and the pump suction pressure by the pump 4.

In addition, when the factory which installs the pipe line washing | cleaning apparatus 1 is equipped with the piping equipment for air supply of required pressure, this air supply piping equipment can also be utilized as the air supply machine 17. FIG.
By the way, the circulating fluid 3 can be circulated between the suction pipe 6, the pump 4, the blowing tube 8, the spray gun 11, and the storage tank 2 by blowing the circulating fluid 3 toward the storage tank 2. I explained what I can do. In this case, it is preferable to dispose the sheet-like filter medium 20 so as to cover the upper opening of the storage tank 2.

By doing in this way, it can prevent that impurities, such as garbage which remain in the spray gun 11 and the blower pipe 8, and a refuse are returned to the storage tank 2. FIG.
The density of the eyes of the filter medium 20 is preferably about 100 mesh when the circulating liquid 3 is used as a paint, and about 250 mesh when a general color excluding metallic is preferable. It becomes. In addition, when the circulating liquid 3 is thinner, water, or the like, a liquid of about 460 mesh is suitable.

Next, the use situation of the pipe line cleaning apparatus 1 according to the present invention will be described. First, the pump 4 is operated in the pipe line facility 10 provided with the pipe line cleaning device 1. Moreover, the air supply machine 17 of the pipe line washing apparatus 1 is operated.
As a result, the circulating liquid 3 stored in the storage tank 2 is sucked up from the suction end 6a of the liquid feeding pipe 5, and the air supplied from the air feeding pipe 16 is mixed with the circulating liquid 3 with turbulent flow. A gas-liquid two-phase flow occurs.

  At this time, since the air contained in the gas-liquid two-phase flow is large exceeding millimeter size, the impurities adhering to or remaining in the liquid feeding pipe 5 are turbulent (finely divided) due to the gas-liquid two-phase flow. Vibrations, violent impacts, or undulations with a strong stirring action). Thereby, even if the impurities are stuck in the liquid feeding pipe 5 with a strong adhesive force, the impurities are surely peeled off and float in the circulating liquid 3.

Therefore, in the case where a path that leads from the suction pipe 6 to the blowout pipe 8 and the spray gun 11 is formed for the liquid feeding pipe 5, the spray gun 11 is spouted to cause impurities from the spray gun 11. The circulating liquid 3 can be jetted out of the storage tank 2 or into the storage tank 2 via the filter medium 20 on the storage tank 2.
In addition, when the supply to the blowout pipe 8 is switched to the return pipe 7 for the liquid supply pipe 5, the circulating liquid 3 is circulated between the suction pipe 6, the pump 4, the return pipe 7, and the storage tank 2. It is also possible to perform intensive cleaning in the route during this period.

FIG. 3 shows a second embodiment of the pipeline cleaning apparatus 1 according to the present invention. In this 2nd Embodiment, between the upper and lower sides of the return end part 7a of the return pipe 7 provided in the liquid sending pipe 5 in order to return the circulating liquid 3 to the storage tank 2, and the liquid level of the circulating liquid 3 in the storage tank 2, A cage-like (shaped like a inverted bell) with a mouth portion 20a facing upward is disposed.
The filter medium 20 is not in contact with the return end portion 7a of the liquid feeding pipe 5, and is held at a distance. In addition, the return end portion 7 a of the liquid feeding pipe 5 is disposed so as to have a height away from the liquid surface of the circulating liquid 3 in the storage tank 2. Further, the secondary side surface (lower end) of the filter medium 20 and the liquid surface of the circulating liquid 3 in the storage tank 2 are not in contact with each other and are held at a distance.

  Therefore, the flowing liquid 3 discharged from the return end portion 7a into the storage tank 2 passes through the filter medium 20 in a natural flow. Furthermore, in the case where the circulating fluid 3 is circulated between the suction pipe 6, the pump 4, the return pipe 7, and the storage tank 2, the circulating fluid 3 passing through the filter medium 20 is pumped by the pump 4. It can be said that it has not received. In short, the filter medium 20 is arranged to be separated from the pump 4 by pressure.

Therefore, impurities such as dust and solids removed from the circulating liquid 3 by the filter medium 20 are not subjected to the suction action by the pump 4 through the secondary side (the flowing liquid 3 after passing) of the filter medium 20.
Thereby, the impurities after being collected in the filter medium 20 are not forced to pass through the filter medium 20, and the circulating liquid 3 in the storage tank 2 is maintained in a purified state. That is, the removed impurities do not contaminate or clog the inside of the pipe, and naturally, they do not adhere to the painted surface and cause defects.

  In addition, the opening part 20a above the filter medium 20 has a size that allows another discharge pipe (for example, the spray gun 11) different from the return end part 7a of the liquid feeding pipe 5 to be inserted. Therefore, it is possible to perform an efficient cleaning operation by inserting the spray gun 11 or the like into the filter medium 20 while keeping the return end portion 7a inserted into the filter medium 20.

In the pipe line facility 10 shown in FIG. 3, a cleaning ability test was performed.
The liquid feeding pipe 5 to be used was about 8 m in total length of the suction pipe 6 and the blowing pipe 8 (excluding the spray gun 11).
Of these, the suction pipe 6 had a length of about 1.5 m and an inner diameter (diameter) of 15 mm. The blowing tube 8 had a length of about 6 m and an inner diameter (diameter) of 8 mm. From this, it can be said that the inner diameter (15 mm) of the suction pipe 6 is the maximum inner diameter of the liquid feeding pipe 5, and the inner diameter (8 mm) of the blowing pipe 8 is the minimum inner diameter of the liquid feeding pipe 5.

The circulating fluid 3 was thinner and the filter medium 20 was 460 mesh.
The air supply pressure of the air supply machine 17 in the pipeline cleaning apparatus 1 was 0.1 MPa, and the pump suction pressure of the pump 4 in the pipeline equipment 10 was 0.4 MPa.
FIG. 4 (A) shows a case where the size of about 0.6 mm in size (left side in the drawing) collected by the filter medium 20 by the operation of the pipe cleaning device 1 cannot be removed. FIG.

Moreover, FIG. 4 (B) cannot remove the same size as the about 0.3 mm-sized piece (left side in the figure) collected by the filter medium 20 by the operation of the pipe cleaning device 1. It is a photograph of a poorly painted surface (right side in the figure) that occurs when
On the other hand, FIG. 4C is a photograph showing the state of the filter medium 20 that has been replaced with a new one after operating the pipe cleaning device 1 for 1 hour or more.

As is clear from the results of FIGS. 4A, 4B, and 4C, impurities such as dust and buoyancy floating in the circulating fluid 3 are obtained by performing the cleaning by the pipe cleaning device 1 according to the present invention. It can be removed almost completely. Needless to say, even if coating is performed using the pipe line equipment 10 after cleaning, defective coating due to impurities such as dust and solids does not occur.
In addition, it is good to perform washing | cleaning by the pipe line washing | cleaning apparatus 1 until it can be judged that the collection of the impurity by the filter medium 20 was lose | eliminated. Further, in order to ensure the safety factor, it is preferable to carry out the cleaning by extending to some extent even after confirming that the collection of impurities by the filter medium 20 has been eliminated.

That is, if cleaning is stopped at a stage where impurities adhered or deposited in the pipeline are in the middle of peeling, there is a risk that impurities will be mixed in the circulation liquid 3 when the circulation liquid 3 is subsequently circulated. Because there is.
Based on the test repeatedly conducted by the present inventors, it is possible to obtain a result that the adhered or accumulated impurities in the pipe line can be surely removed by securing a cleaning time of about 1 hour under the test conditions. It was.

By the way, this invention is not limited to the said embodiment, It can change suitably according to embodiment.
For example, the pipe cleaning device 1 according to the present invention is provided for each of the coating tank, the diluent tank, and the cleaning liquid tank, and is used when necessary. It is also possible to use it by attaching it to each tank of the cleaning liquid tank.

  The pipe cleaning device 1 according to the present invention is not limited to be implemented in a coating apparatus, and can be implemented in any field including a pipe through which a liquid flows.

1 pipe cleaning apparatus 2 storage tank 3 flows fluid 4 pump 5 liquid feed pipe 6 suction tube 6a Sucking narrowing end 7 regression tube 7a feeding regression end 8 blowoff pipe 10 pipe plant 11 spray gun 16 tracheal 16a air intake portion 16b air Discharge part 17 Air supply machine 20 Filter medium 20a Mouth part

Claims (5)

In the pipeline cleaning device provided for the pipeline equipment that pumps the circulating liquid stored in the storage tank to the liquid feeding pipe by a pump,
An air supply pipe that arranges an air intake part outside the storage of the circulating liquid and arranges an air discharge part during storage of the circulating liquid;
An air supply device that discharges air taken in from the air intake portion of the air pipe into air bubbles or airflows of a millimeter size or more from the air discharge portion, and
The air discharge portion of the air tube that is located close to the range of the air discharged from the feed pipe with respect to the suction end of the liquid supply tube provided toward the storage tank is respirable When the pump and the air supply device are operated, the liquid flowing in the liquid feeding pipe is converted into a turbulent flow of gas-liquid two-phase flow including air bubbles or air bubbles of millimeter size or larger, and the inside of the liquid feeding pipe is washed. A pipe cleaning device.   When the suction end of the liquid feeding pipe is disposed facing downward, the air discharge portion of the air feeding pipe is coaxial with the suction end downward and upward with respect to the suction end of the liquid feeding pipe. The pipe cleaning apparatus according to claim 1, wherein the pipe cleaning apparatus is disposed in the pipe.   The liquid supply pipe is formed with a piping path including the storage tank to generate a circulating flow, and the return end of the liquid supply pipe for returning the circulating liquid to the storage tank receives the pump pressure of the pump. 3. The pipe line cleaning device according to claim 1, wherein the filter medium is disposed in such a manner that the filter medium is separated in pressure. The liquid supply pipe has a blow-out pipe that switches the return flow to the return end and supplies the circulating liquid to the outside of the storage tank.
The pipe line cleaning device according to claim 3, wherein the filter medium has a mouth portion having a diameter that allows a discharge pipe provided at a tip end portion of the blowing pipe to be inserted.   The pipe cleaning apparatus according to any one of claims 1 to 4, wherein the liquid feeding pipe supplies paint to a spray gun.