JP2012055845A - Method and apparatus for cleaning tap-water piping - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for cleaning tap-water piping, capable of attaining a sufficient cleaning effect with respect to tap-water piping of a relatively large diameter of, for example, 75 to 150 mm.SOLUTION: The method of cleaning tap-water piping comprises repeating injection and suspending injection of carbon dioxide into tap-water piping 1 wherein tap water is flowing, namely intermittently injecting carbon dioxide thereinto to form spaces S1, S2 comprising carbon dioxide by the injection thereof and to form a sandwich structure constituted of the spaces S1, S2 comprising carbon dioxide and of a water mass (W mass) formed upon suspending the injection of carbon dioxide and sandwiched therebetween, whereby matter sticking to/deposited on the inner wall face of the tap-water piping 1 is removed therefrom by an impact force given thereto by the water mass (W mass) flowing therein and colliding with the sticking/deposited matter.

Description

  The present invention relates to a tap water pipe cleaning method and apparatus for cleaning and removing dirt adhering to and accumulating on the inner surface of a tap water pipe (water pipe).

  Examples of tap water pipes (water pipes) include cast iron pipes, mortar lining pipes, and hard vinyl chloride pipes. These pipes need to be cleaned because of the accumulation of scale and sediment on the inner wall of the pipe after long-term use. Conventionally, as a method of removing dirt adhering to and accumulating on the inner surface of a water pipe, a method of discharging the adhering deposit by increasing the flow velocity in the pipe by discharging water from a fire hydrant, and inserting a cleaning brush into the pipe and using a cleaning brush A method of cleaning the inner surface of the pipe by mechanically rubbing the inner wall surface of the pipe and a method of cleaning the inner surface of the pipe by inserting an elastic body called a pig into the pipe and bringing the outer peripheral surface of the pig into contact with the inner wall surface of the pipe. However, each method has a problem of the length of the object to be cleaned, a problem that piping work such as partial disassembly and reassembly of the pipe for inserting the cleaning brush into the pipe is necessary (specifically, In order to insert the cleaning brush and pig, it is necessary to remove the fire hydrant and the repair valve attached below it), problems such as clogging of the elastic body inserted in the pipe, and in the case of the cleaning brush, high pressure Since the hose is inserted into the pipe while dragging, there is a problem that it cannot be applied to a pipe with many bends, and the washing method is not always sufficient.

  In addition, as described in Patent Document 1, as a method for cleaning tap water pipes (water pipes), carbon dioxide gas is intermittently or continuously driven into the pipes to dissolve carbon dioxide dissolved in the water in the pipes. There is also a method of cleaning the inside of the tube by a foaming action. In this method, the dissolved carbon dioxide gas is vaporized by circulating water through the tube, and the inside of the tube is washed by the action of the vaporized carbon dioxide gas.

Japanese Patent No. 3501795

  However, in order to remove the deposits in the pipe by blowing the carbon dioxide gas into the pipe and dissolving the carbon dioxide dissolved in the water in the pipe, the pipe diameter of 15 mm to 25 mm piped separately for each house such as an apartment or an apartment. It is effective for small-diameter pipes in the range of, however, pipes with large pipe diameters of 75 mm to 150 mm and many complicated branches, such as underground water pipes (water pipes) buried underground. On the other hand, it was difficult to remove the deposited deposits only by the foaming action of carbon dioxide dissolved in water. In addition, it is difficult to remove the deposits by the action of the vaporized carbon dioxide gas by flowing the water in the pipe, vaporizing the dissolved carbon dioxide gas, and the deposits are removed by the foaming action. However, there is also a problem that it takes a long time to discharge the removed deposits from the piping to the outside of the system.

  The present invention has been made in view of the above circumstances, and provides a cleaning method and apparatus for tap water piping that can obtain a sufficient cleaning effect for a tap water piping having a relatively large aperture, for example, 75 mm to 150 mm. It is intended to do.

  In order to achieve the above-mentioned object, the present inventors have made various studies and have conceived that a gas-liquid two-phase flow using a compressible fluid is used for the removal of deposits in the pipe. This is an attempt to use carbon dioxide gas which is harmless to human body as a sexual fluid.

Next, the basic concept of the tap water pipe cleaning method of the present invention will be described with reference to FIG. 1 and FIG.
As shown in FIG. 1A, a tap water pipe 1 is installed, and the tap water pipe 1 is filled with tap water and flows from the left side to the right side. Here, when the cross-sectional area of the tap water pipe 1 is A and the flow rate of the tap water flowing through the pipe is Q _L , the average flow velocity in the pipe of the tap water pipe 1 can be expressed as V _L = Q _L / A. A carbon dioxide gas inlet 2 for injecting carbon dioxide gas into the tap water pipe 1 is provided on the upstream side of the tap water pipe 1. A discharge port 3 for discharging the liquid flowing in the tap water pipe 1 is provided on the downstream side of the tap water pipe 1. The downstream end of the tap water pipe 1 is closed by a closing plate 4.

Then, while flowing tap water at a flow rate Q _L, as shown in FIG. 1 (b), a predetermined time injecting carbon dioxide gas at a predetermined flow rate of tap water pipe 1. Here, the flow rate of carbon dioxide gas is Q _G. In this way, when carbon dioxide is injected into the tap water pipe 1 at a flow rate Q _G for a predetermined time, the average flow velocity in the tube becomes V _{L + G} = (Q _L + Q _G ) / A, and the flow velocity in the tube is equal to the volume of carbon dioxide injected. Increased speed. By injecting carbon dioxide, a carbon dioxide space S1 filled with carbon dioxide is formed in the pipe of the tap water pipe 1.

Next, as shown in FIG. 1C, the injection of carbon dioxide gas is stopped for a predetermined time. The average flow velocity in the tube at this time is V _L = Q _L / A. Thereafter, as shown in FIG. 1 (d), by injecting carbon dioxide at a flow rate Q _G for a predetermined time, the average flow velocity in the tube becomes V _{L + G} = (Q _L + Q _G ) / A, and the flow velocity in the tube is injected with carbon dioxide. The speed is increased by the volume. By injecting carbon dioxide, a carbon dioxide space S2 filled with carbon dioxide is formed in the tap water pipe 1. Therefore, a sandwich structure is formed in which a water mass (Wmass) formed when carbon dioxide injection is stopped is sandwiched between the carbon dioxide space S1 and the carbon dioxide space S2. Since the carbon dioxide gas space S1 and the carbon dioxide gas space S2 are spaces where a predetermined amount of carbon dioxide gas is injected and the pressure is high, the water mass (Wmass) does not collapse due to gravity, and the inside of the pipe line It is in contact with the entire circumference of the wall. That is, the water mass (Wmass) has a cross-sectional area equivalent to that of the tap water pipe 1. The carbon dioxide spaces S1 and S2 do not have to occupy the entire cross-sectional area of the pipeline, and tap water may be included in part.

Next, as shown in FIG. 1E, the injection of carbon dioxide gas is stopped for a predetermined time. In this way, after injecting carbon dioxide gas into the tap water pipe 1 filled with tap water for a predetermined time, the carbon dioxide gas injection is stopped for a predetermined time, and then carbon dioxide is intermittently injected for a predetermined time. By sequentially repeating the injection procedure, a sandwich structure of water mass (Wmass) sandwiched between the carbon dioxide space S1 and the carbon dioxide space S2 is sequentially formed, and the water mass (Wmass) is accelerated as described above. V _{L + G} moves through the pipe, and since carbon dioxide is a compressible fluid, the flow rate equivalent to the tap water flowing through the pipe, the flow rate equivalent to the carbon dioxide pipe, the carbon dioxide injection time, and the injection stop time are appropriate. By setting to a small value, a good gas-liquid two-phase flow in which a water mass (Wmass) is sandwiched between two carbon dioxide gas spaces S1 and S2 can be formed. Here, the in-pipe equivalent flow rate is a value obtained by dividing the flow rate by the cross-sectional area of the target pipe.

Next, a mechanism for removing adhesion / sediment (dirt) adhering to and accumulating on the pipe wall surface when the water mass (Wmass) sandwiched between the carbon dioxide space S1 and the carbon dioxide space S2 moves in the pipe. explain.
FIG. 2 is an enlarged view of a main part of FIG. 1 (d), and is a half sectional view of a tap water pipe. As shown in FIG. 2, the water mass (Wmass) moves in the pipe at a pipe flow velocity _{VL + G.} And a water mass (Wmass) collides with the adhesion and deposit M of the inner wall surface of the tap water piping 1 during movement, and gives an impact force. Here, a small part of the water mass (Wmass) collides with the deposit / sediment M, and if the minute volume flow rate of the colliding portion is Q and the density of the water mass (Wmass) is ρ, The impact force F applied to the deposit M can be expressed by the following equation. In this case, the minute volume flow Q that collides with the deposit / sediment M corresponds to the volume flow that collides with the projected area of the deposit / sediment M perpendicular to the flow of tap water.
F = ρ × Q × V _{L + G} (1)
Here, although a very small amount of carbon dioxide is dissolved in the water mass (Wmass), ρ≈1 since most of the components are tap water.
Therefore, it can be expressed as F≈Q × V _{L + G.}
That is, the adhering / sediment M on the inner wall surface of the tap water pipe 1 has an impact force obtained by multiplying the minute volume flow rate Q that collides with the adhering / sediment M and the in-pipe flow velocity V _{L + G of the} water mass (Wmass). Will join. Since the impact force applied to the adhesion / deposit M is repeated by the water mass (Wmass) generated one after another, the adhesion / deposition M can be reliably removed from the inner wall of the pipe. Since the flow velocity of the water mass (Wmass) is the average flow velocity V _{L + G} in the pipe increased by the injection of carbon dioxide gas, the impact force applied to the adhesion / deposit M can be increased. And the physical force (shearing force) acts so that the whole adhesion and deposits (dirt) of the inner wall surface of the pipe can be scraped off by the water mass (Wmass) repeatedly generated, and the inside of the pipe can be cleaned. .

  As is apparent from the basic concept described above, the tap water pipe cleaning method of the present invention is an intermittent process of carbon dioxide that repeats the injection of carbon dioxide and the stop of carbon dioxide injection into the tap water pipe through which tap water flows. A carbon dioxide gas space is formed by injecting carbon dioxide gas into the tap water pipe, and a sandwich structure is formed that sandwiches a water mass (Wmass) formed when carbon dioxide gas injection is stopped by the carbon dioxide gas space. When a water mass (Wmass) flows through the tap water pipe, it adheres to the inner wall surface of the pipe and collides with the adhering / depositing matter to apply an impact force to remove the adhering / depositing substance. It is what.

In a preferred aspect of the present invention, the water mass (Wmass) is in contact with the entire circumference of the inner wall surface of the tap water pipe.
According to the present invention, since the water mass (Wmass) is in contact with the entire circumference of the inner wall surface of the tap water pipe, the dirt on the entire inner wall surface of the pipe is scraped off by the high-speed flow of the water mass (Wmass). be able to.

In a preferred aspect of the present invention, the cross-sectional area of the tap water pipe is A, the flow rate of tap water flowing through the tap water pipe is Q _L , and the flow rate of carbon dioxide gas injected into the tap water pipe is Q _G. Then, the average flow velocity in the pipe when carbon dioxide injection is stopped is V _L = Q _L / A, and the average flow speed in the pipe is increased to V _{L + G} = (Q _L + Q _G ) / A by injecting the carbon dioxide gas. It is speeded.
According to the present invention, when the carbon dioxide gas is not injected, the average flow velocity in the pipe is V _L = Q _L / A, whereas the average flow velocity in the pipe is V _{L + G} = (Q _{L +} Q G) _{/ a,} and the can be accelerated in the tube average flow velocity by the injection of carbon dioxide. Therefore, it is possible to increase the impact force applied from the water mass (Wmass) to the adhesion / deposit on the inner wall surface of the pipe.

  Furthermore, the inventors have effectively supplied the carbon dioxide gas at a predetermined flow rate, supplied a predetermined range of tap water flow rate, and supplied carbon dioxide gas into the pipe at a predetermined injection frequency for cleaning. It came to the knowledge that the deposit could be removed. That is, the present inventors set the equivalent flow velocity of tap water flowing in the pipe to 0.3 m / sec or more, the equivalent flow velocity of carbon dioxide gas to 3 m / sec or more, and intermittent injection of carbon dioxide gas. By setting the stop to 1 to 2 seconds at ~ 5 seconds, a high-speed gas-liquid two-phase flow in which a water mass (Wmass) is sandwiched by two carbon dioxide spaces is efficiently generated. It was found that adhesion and deposits on the inner wall surface of the pipe can be removed by applying an impact force to the inner wall surface of the pipe.

  A preferred embodiment of the present invention has been made on the basis of such findings, and the equivalent flow velocity in the tap water flowing in the tap water pipe is 0.3 m / sec or more, and the equivalent flow velocity in the pipe of carbon dioxide gas. Is set to 3 m / sec or more, the intermittent injection of carbon dioxide gas is set to 4 to 5 seconds, and the stop is set to 1 to 2 seconds.

  In order to more efficiently clean the pipeline, the equivalent flow rate of tap water flowing through the pipe is set to 0.3 to 0.7 m / sec, and the equivalent flow rate of carbon dioxide gas is set to 3 to 8 m / sec. In addition, it is desirable to set intermittent injection of carbon dioxide gas to 4 seconds for injection and stop for 2 seconds.

Furthermore, since the present inventors intermittently inject carbon dioxide into the tap water piping of the running water, there is a difference in density in the amount of carbon dioxide dissolved in the running water, so that the water mass (Wmass) In order to obtain a more stable gas-liquid two-phase flow sandwiched between two carbon dioxide spaces and to obtain a higher-speed gas-liquid two-phase flow, saturated carbonated water is continuously injected into the tap water pipe, It came to the knowledge that it was necessary to keep gas dissolution concentration uniform.
A preferred embodiment of the present invention is made based on such knowledge, and is characterized in that carbonated water is continuously supplied into the tap water pipe.

In addition, the present inventors further stabilize the gas-liquid two-phase flow in which the water mass (Wmass) is sandwiched between two carbon dioxide spaces, and obtain a high-speed gas-liquid two-phase flow. It has been found that a high-speed and stable gas-liquid two-phase flow can be obtained by suctioning the inside of the pipe from the drain port with a negative pressure.
A preferred aspect of the present invention is made based on such knowledge, and is characterized in that the inside of the tap water pipe is sucked from the drain port of the tap water pipe with a negative pressure.

  In addition to intermittent injection of carbon dioxide gas into the tap water pipe, the present inventors have repeatedly conducted an experiment of supplying carbonated water into the tap water pipe and sucking the tap water pipe at a negative pressure. Supplying a flow rate of saturated carbonated water in a range, a supply flow rate of carbon dioxide gas in a predetermined range, a flow rate of tap water in a predetermined range, and supplying carbon dioxide gas into the tube at a predetermined injection frequency to perform cleaning effectively It has come to the knowledge that it is possible to remove the deposits and deposits. That is, the present inventors set the pipe equivalent flow rate of tap water flowing in the pipe to 0.3 m / sec or more and the supply amount of saturated carbonated water to be continuously supplied to the pipe equivalent flow rate of 0.05 m / sec or more. And the equivalent flow rate of carbon dioxide in the pipe is 3 m / sec or more, the intermittent injection of carbon dioxide is 4 to 5 seconds, the stop is 1 to 2 seconds, and the suction flow rate for sucking the inside of the pipe is By setting the flow velocity in the pipe to be 5 m / sec or more, a high-speed gas-liquid two-phase flow in which a water mass (Wmass) is sandwiched between two carbon dioxide spaces is efficiently generated. It was found that adhesion and deposits on the inner wall surface of the pipe can be removed by applying an impact force to the inner wall surface of the pipe.

  A preferred embodiment of the present invention has been made on the basis of such findings, and the equivalent flow velocity in the tap water flowing in the tap water pipe is 0.3 m / sec or more, and the equivalent flow velocity in the pipe of carbon dioxide gas. Is set to 3 m / sec or more, intermittent injection of carbon dioxide gas is set to 4 to 5 seconds, and stop is set to 1 to 2 seconds. Further, saturated carbonated water is continuously added, and the supply amount is equivalent to the flow rate in the pipe. Further, the suction flow rate for sucking the inside of the pipe is set so that the in-pipe equivalent flow rate becomes 5 m / sec or more so that the pressure becomes 0.05 m / sec or more.

  In addition, in order to perform washing | cleaning of the said pipe line more efficiently, the pipe | tube equivalent flow speed in the pipe | tube of the tap water which flows in the pipe | tube in 0.3-0.7m / sec and the saturated carbonated water which supplies continuously is equivalent. 0.05 m / sec to 0.25 m / sec, the equivalent flow rate of carbon dioxide in the pipe to 3 to 8 m / sec, intermittent injection of carbon dioxide in 4 seconds, stop for 2 seconds, and in the pipe It is desirable to set the suction flow rate to be sucked so that the equivalent flow velocity in the tube is 5 m / sec to 12 m / sec.

The tap water pipe cleaning device according to the present invention is a carbon dioxide gas injection device that intermittently injects carbon dioxide gas into the tap water pipe through which tap water flows and repeatedly injects carbon dioxide gas and stops injection of carbon dioxide gas. The carbon dioxide gas injection device is connected to the tap water pipe, and a carbon dioxide gas space is formed by injecting carbon dioxide gas into the tap water pipe, and a water mass formed when the carbon dioxide gas injection is stopped by the carbon dioxide gas space ( A sandwich structure sandwiching (Wmass), and when the water mass (Wmass) flows through the tap water pipe, it adheres to the inner wall surface of the pipe and collides with the deposit / deposit that gives impact force and gives The deposit is removed.
A preferred embodiment of the present invention is characterized by comprising a carbonated water production apparatus that continuously supplies carbonated water into the tap water pipe.
A preferred embodiment of the present invention is characterized by comprising a vacuum generator that sucks the inside of the tap water pipe with a negative pressure from the outlet of the tap water pipe.

  According to the present invention, by intermittently injecting carbon dioxide gas into the tap water piping through water, a high-speed gas-liquid two-phase flow in which a water mass (Wmass) is sandwiched between two carbon dioxide spaces is efficiently produced. When the gas-liquid two-phase flow generates an impact force on the inner wall surface of the pipe, adhesion / deposit on the inner wall surface of the pipe can be removed. Therefore, a strong cleaning effect can be obtained and the cleaning time can be shortened, and the cleaning efficiency can be greatly improved.

FIG. 1 is a schematic diagram showing a flow state of fluid in a pipe when carbon dioxide gas is intermittently injected into a tap water pipe. FIG. 2 is an enlarged view of a main part of FIG. 1 (d), and is a half sectional view of a tap water pipe. FIG. 3 is a schematic view showing a first embodiment of a tap water pipe cleaning method and apparatus according to the present invention. FIG. 4 is a schematic diagram showing a state in which a high-speed gas-liquid two-phase flow in which a water mass (Wmass) is sandwiched between two carbon dioxide spaces is formed by intermittently injecting carbon dioxide into a tap water pipe. FIG. FIG. 5 is a schematic view showing a second embodiment of the tap water pipe cleaning method and apparatus according to the present invention. FIG. 6 is a schematic view showing a state in which a high-speed gas-liquid two-phase flow in which a water mass (Wmass) is sandwiched between two carbon dioxide spaces is formed by intermittently injecting carbon dioxide into a tap water pipe. FIG.

Embodiments of a tap water pipe cleaning method and apparatus according to the present invention will be described below with reference to FIGS. 3 to 6, the same or corresponding components are denoted by the same reference numerals, and redundant description is omitted.
FIG. 3 is a schematic view showing a first embodiment of a tap water pipe cleaning method and apparatus according to the present invention. In FIG. 3, the pipe 10 to be cleaned simulates an actual tap water pipe (water pipe), and confirms the state of the fluid flow in the pipe 11, the pipe 11 having a diameter of 100 mm, the pipe 12 having a diameter of 150 mm. A transparent acrylic pipe having a diameter of 100 mm and a pipe having a diameter of 150 mm, a carbon dioxide injection seat 15 simulating a fire hydrant for injecting carbon dioxide gas, and a discharge port 16 simulating a fire hydrant used as a washing drain discharge port And a closing plate 17 that simulates a gate valve that partitions the area to be cleaned of tap water piping.

  A carbon dioxide gas injection device 20 for intermittently injecting carbon dioxide gas into the cleaning target pipe 10 includes a carbon dioxide gas cylinder 21, a vaporizer 22 that vaporizes carbon dioxide gas supplied from the carbon dioxide gas cylinder 21, and a vaporizer 22. An electromagnetic valve 23 for intermittently injecting the vaporized carbon dioxide gas into the cleaning target pipe 10 and a timer 24 for opening and closing the electromagnetic valve 23 are configured. The carbon dioxide injection device 20 and the carbon dioxide injection seat 15 of the pipe 10 to be cleaned are connected by a hose 26, and the hose 26 measures a supply flow rate of carbon dioxide supplied from the carbon dioxide injection device 20. 27 is installed. The carbon dioxide gas injected into the cleaning target pipe 10 uses carbon dioxide for food from the viewpoint of safety and hygiene. Carbon dioxide gas that dissolves easily in tap water in order to prevent air burst, which is a problem when using tap water after washing, due to the complicated branch pipes and branch pipes of tap water piping. Is used.

  The simulated facility for supplying tap water to the pipe 10 to be cleaned adjusts the flow rate of tap water discharged from the feed water tank 30, the feed water pump 31 that pumps the tap water stored in the feed water tank 30, and the feed water pump 31. And a flow meter 33 for measuring the flow rate of tap water after being adjusted by the flow rate control valve 32, and a hose 34 for connecting these devices and the inlet end of the pipe 10 to be cleaned. Has been.

  Moreover, the waste water treatment apparatus 40 for processing the cleaning waste water discharged from the discharge port 16 of the pipe 10 to be cleaned receives a waste water receiving tank 41 for receiving the cleaning waste water and separating carbon dioxide, and a removed foreign matter in the cleaning waste water. , A neutralization tank 43 for neutralizing the washing waste water, a submersible pump 44 and a hose 45 for transferring the washing waste water from the drain receiving tank 41 to the neutralization tank 43, It consists of a submersible pump 46 and a hose 47 for transferring the washed waste water after neutralization in the sum tank 43 to the outside.

  By using the cleaning device configured as shown in FIG. 3 and intermittently injecting carbon dioxide from the carbon dioxide injection device 20 into the cleaning target pipe 10, as shown in FIG. A sandwich structure of water mass (Wmass) sandwiched between the carbon dioxide gas spaces S2 is sequentially formed. The state of the fluid shown in FIG. 4 can be confirmed in the transparent acrylic pipes 13 and 14. Then, the impact force applied to the inner wall surface of the water mass (Wmass) accelerated by the increase in the volume of carbon dioxide gas promotes the separation and removal of deposits and deposits in the pipe. FIG. 2 shows a mechanism for removing adhesion / sediment (dirt) adhering to and accumulating on the inner wall of the pipe when the water mass (Wmass) sandwiched between the carbon dioxide space S1 and the carbon dioxide space S2 moves in the pipe. As shown.

  Using the cleaning device configured as shown in FIG. 3, the test is performed using parameters corresponding to the pipe equivalent flow velocity of tap water, the equivalent flow velocity of carbon dioxide gas, and the intermittent injection frequency of carbon dioxide gas as parameters. Various conditions for generating a high-speed gas-liquid two-phase flow that gives impact force necessary for adhesion and deposit removal on the inner surface of the pipes were examined. As a result, the tap water equivalent flow rate of tap water flowing in the pipe is 0.3 m / sec or more, the carbon dioxide equivalent flow rate is 3 m / sec or more, and intermittent injection of carbon dioxide gas is performed for 4 to 5 seconds. By setting the stop to 1 to 2 seconds, a high-speed gas-liquid two-phase flow in which a water mass (Wmass) is sandwiched between two carbon dioxide gas spaces S1 and S2 can be generated efficiently. It was verified that the liquid two-phase flow can remove the deposits and deposits on the inner wall of the pipe by applying an impact force to the inner wall of the pipe.

  Here, in the gas-liquid two-phase flow, the tap water equivalent flow rate in the pipe is less than 0.3 m / sec, the equivalent flow rate in the pipe of carbon dioxide gas is less than 3 m / sec, or intermittent injection of carbon dioxide is the injection 4 to 4 If it deviates from the range of 5 seconds and stop 1 to 2 seconds, it becomes difficult to generate a high-speed gas-liquid two-phase flow sufficient to remove deposits on the inner surface of the pipe, and sufficient pipe cleaning cannot be performed. found. Further, even if the equivalent flow rate in the tap water pipe is extremely increased, the cleaning effect is not significantly improved. For example, the equivalent flow speed in the tap water pipe is set to a range larger than 0.7 m / sec, or Even if the equivalent flow rate of carbon dioxide in the pipe is set to a range larger than 8 m / sec, there is no significant improvement in gas-liquid two-phase flow, and conversely, wasteful consumption of tap water and carbon dioxide is increased, leading to an increase in cost. There is a fear. Moreover, when the flow rate corresponding to the tap water in the pipe was simply set in a range larger than 0.7 m / sec, the amount of carbon dioxide dissolved in water increased, and a good gas-liquid two-phase flow did not occur. From these experimental results, the cleaning conditions are as follows: tap water equivalent flow rate of tap water flowing in the pipe is 0.3 to 0.7 m / sec, carbon dioxide equivalent flow rate of 3 to 8 m / sec, and carbon dioxide gas flow rate. It is desirable to set the intermittent injection frequency to 4 seconds for injection and 2 seconds for stoppage.

  Next, Table 1 shows the results of tests conducted using parameters corresponding to the pipe water equivalent flow velocity, the carbon dioxide equivalent flow velocity, and the intermittent injection frequency of carbon dioxide.

  FIG. 5 is a schematic view showing a second embodiment of the tap water pipe cleaning method and apparatus according to the present invention. The cleaning device of the second embodiment shown in FIG. 5 has a configuration in which a carbonated water production device 50, a vacuum generator 60, and the like are added to the cleaning device of the first embodiment shown in FIG. That is, the pipe 28 branched from the outlet of the vaporizer 22 of the carbon dioxide injection device 20 is connected to the carbonated water production device 50. The carbonated water production apparatus 50 includes a carbonated water production water tank 51, a carbonated water production pump 52, a carbonated water flow meter 53, and a carbonated water production unit 54. The carbonated water production device 50 produces saturated carbonated water by dissolving the carbon dioxide gas supplied from the vaporizer 22 of the carbon dioxide gas injection device 20 in tap water. The carbonated water production unit 54 of the carbonated water production apparatus 50 is connected to the carbon dioxide gas injection seat 15 by a hose 29 so that saturated carbonated water can be continuously supplied to the pipe 10 to be cleaned.

  Further, in the cleaning device of the second embodiment shown in FIG. 5, the waste water treatment device 40 for processing the cleaning waste water discharged from the discharge port 16 of the cleaning target pipe 10 includes a negative pressure tank 37. . The discharge port 16 of the cleaning target pipe 10 is connected to a negative pressure tank 37 through a pressure hose 38. Further, the negative pressure tank 37 is connected to the vacuum generation device 60 via the suction hose 39, and the negative pressure tank 37 is negatively pressurized by the vacuum generation device 60, whereby the cleaning target pipe 10 is cleaned via the pressure resistance hose 38. Drainage, carbon dioxide, etc. can be sucked. Further, the waste water treatment device 40 receives the washing waste water and separates the negative pressure tank 37 for separating carbon dioxide, the filter 42 for collecting the removed foreign matter in the washing waste water, and the neutralizing treatment for the washing waste water. Neutralization tank 43, submersible pump 44 and hose 45 for transferring cleaning wastewater from negative pressure tank 37 to neutralization tank 43, and for transferring cleaning wastewater after neutralization in neutralization tank 43 to the outside A submersible pump 46 and a hose 47 are included.

  By using the cleaning device configured as shown in FIG. 5 and intermittently injecting carbon dioxide gas from the carbon dioxide injection device 20 into the pipe 10 to be cleaned, as shown in FIG. A sandwich structure of water mass (Wmass) sandwiched between the carbon dioxide gas spaces S2 is sequentially formed. The state of the fluid shown in FIG. 6 can be confirmed in the transparent acrylic pipes 13 and 14. Then, the impact force applied to the inner wall surface of the water mass (Wmass) accelerated by the increase in the volume of carbon dioxide gas promotes the separation and removal of deposits and deposits in the pipe. FIG. 2 shows a mechanism for removing adhesion / sediment (dirt) adhering to and accumulating on the inner wall of the pipe when the water mass (Wmass) sandwiched between the carbon dioxide space S1 and the carbon dioxide space S2 moves in the pipe. As shown.

  Since carbon dioxide gas is intermittently injected into the tap water piping of the running water, a difference in density occurs in the amount of dissolved carbon dioxide in the running water, so that the water mass (Wmass) has two carbon dioxide gas spaces S1, In order to stably obtain a high-speed gas-liquid two-phase flow sandwiched in S2, saturated carbonated water is continuously supplied. As a result, the concentration of carbon dioxide in tap water to which carbon dioxide is intermittently supplied becomes almost uniform, and a stable and high-speed gas-liquid two-phase flow can be obtained. -The cleaning action to be removed can be promoted.

  Further, by connecting the vacuum generator 60 to the negative pressure tank 37 connected to the discharge port 16 of the pipe 10 to be cleaned, the pipe of the pipe 10 to be cleaned can be sucked with negative pressure, and the system in the pipe The pressure difference increases, the high-speed gas-liquid two-phase flow increases dramatically, and the cleaning action for peeling and removing the deposits and deposits in the pipe can be promoted.

  Using the cleaning device configured as shown in FIG. 5, the test was performed using parameters corresponding to the pipe equivalent flow rate of tap water, the equivalent flow rate of saturated carbonated water in the pipe, the equivalent flow rate of carbon dioxide in the pipe, and the intermittent injection frequency of carbon dioxide. Various conditions for generating a high-speed gas-liquid two-phase flow that gives an impact force necessary for adhesion and deposit removal on the inner surface of the pipe in the transparent acrylic pipes 13 and 14 incorporated in the pipe 10 to be cleaned were examined. As a result, the equivalent flow rate of tap water flowing through the pipe is 0.3 m / sec or more, and the supply amount of saturated carbonated water to be continuously supplied is 0.05 m / sec or more, and By setting the equivalent flow rate of carbon dioxide in the pipe to 3 m / sec or higher, intermittent injection of carbon dioxide to 4 to 5 seconds, and stopping to 1 to 2 seconds, the water mass (Wmass) is two carbon dioxide. It is possible to efficiently generate a high-speed gas-liquid two-phase flow sandwiched between the spaces S1 and S2, and the high-speed gas-liquid two-phase flow gives an impact force to the inner wall surface of the pipe line. It was verified that it was possible to remove adhesion and deposits.

  Here, in the gas-liquid two-phase flow, the tap water equivalent flow rate in the pipe is less than 0.3 m / sec, the equivalent flow rate in the pipe of carbon dioxide gas is less than 3 m / sec, or intermittent injection of carbon dioxide is the injection 4 to 4 If it deviates from the range of 5 seconds and stop 1 to 2 seconds, it becomes difficult to generate a high-speed gas-liquid two-phase flow sufficient to remove deposits on the inner surface of the pipe, and sufficient pipe cleaning cannot be performed. found. Further, even if the equivalent flow rate in the tap water pipe is extremely increased, the cleaning effect is not significantly improved. For example, the equivalent flow speed in the tap water pipe is set to a range larger than 0.7 m / sec, or Even if the equivalent flow rate of carbon dioxide in the pipe is set to a range larger than 8 m / sec, there is no significant improvement in gas-liquid two-phase flow, and conversely, wasteful consumption of tap water and carbon dioxide is increased, leading to an increase in cost. There is a fear. In addition, the saturated carbonated water supplied continuously is supplied at a flow rate equivalent to 0.25 m / sec or more in the pipe, and the suction flow rate for sucking the inside of the pipe is set to 12 m / sec or more in the pipe. However, the supply facilities were excessive and not effective. Moreover, when the flow rate corresponding to the tap water in the pipe was simply set in a range larger than 0.7 m / sec, the amount of carbon dioxide dissolved in water increased, and a good gas-liquid two-phase flow did not occur. From these experimental results, the cleaning conditions are as follows: the equivalent flow rate of tap water flowing in the pipe is 0.3 to 0.7 m / sec, and the supply amount of saturated carbonated water to be continuously supplied is 0. 05m / sec to 0.25m / sec, the equivalent flow rate of carbon dioxide in the pipe is 3 to 8m / sec, the intermittent injection frequency of carbon dioxide is 4 seconds, the stop is 2 seconds, and piping It is desirable to set the suction flow rate for sucking the inside so that the flow velocity corresponding to the inside of the tube is 5 m / sec to 12 m / sec.

  Next, as a result of testing, the equivalent flow rate in tap water, the equivalent flow rate in saturated carbonated water, the equivalent flow rate in carbon dioxide, the equivalent flow rate in suction during negative pressure suction, and the intermittent injection frequency of carbon dioxide were used as parameters. Is shown in Table 2.

  Although the embodiment of the present invention has been described so far, the present invention is not limited to the above-described embodiment, and it is needless to say that the present invention may be implemented in various different forms within the scope of the technical idea.

DESCRIPTION OF SYMBOLS 1 Tap water piping 2 Carbon dioxide injection port 3 Outlet 4 Closure plate 10 Pipe to be cleaned 11-14 Piping 15 Carbon dioxide injection seat 16 Discharge port 17 Closure plate 20 Carbon dioxide injection device 21 Carbon dioxide cylinder 22 Vaporizer 23 Solenoid valve 24 Timer 26 Hose 27 Flow meter 28 Piping 29 Hose 30 Water tank 31 Water pump 32 Flow control valve 33 Flow meter 34 Hose 37 Negative pressure tank 38 Pressure hose 39 Suction hose 40 Waste water treatment device 41 Drainage receiving tank 42 Filter 43 Neutralization tank 44 Underwater Pump 45 Hose 46 Submersible pump 47 Hose 50 Carbonated water production equipment 51 Carbonated water production tank 52 Carbonated water production pump 53 Carbonated water flow meter 54 Carbonated water production unit 60 Vacuum generator S1, S2 Carbon dioxide space Wmass Water mass

Claims (18)

In the tap water pipe through which tap water is flowing, intermittent injection of carbon dioxide gas that repeats injection of carbon dioxide gas and carbon dioxide injection stop,
Forming a carbon dioxide gas space by injecting carbon dioxide gas into the tap water pipe, forming a sandwich structure sandwiching a water mass formed when carbon dioxide gas injection is stopped by the carbon dioxide gas space,
When the water mass flows through the tap water pipe, it adheres to and adheres to the deposit / deposit deposited on the inner wall surface of the pipe, and an impact force is applied to remove the deposit / deposit. How to clean tap water piping.   The method of cleaning a tap water pipe according to claim 1, wherein the water mass is in contact with the entire circumference of the inner wall surface of the tap water pipe. When the cross-sectional area of the tap water pipe is A, the flow rate of tap water flowing through the tap water pipe is Q _L , and the flow rate of carbon dioxide gas injected into the tap water pipe is Q _G , the injection of carbon dioxide gas The average flow velocity in the pipe at the time of stopping is V _L = Q _L / A, and the average flow velocity in the pipe is increased to V _{L + G} = (Q _L + Q _G ) / A by injecting carbon dioxide gas. The method for cleaning tap water piping according to claim 1 or 2.   The equivalent flow velocity in the tap water pipe flowing in the tap water pipe is 0.3 m / sec or more, the equivalent flow velocity of the carbon dioxide gas pipe is 3 m / sec or more, and the intermittent injection of carbon dioxide gas is 4 to 5 seconds. The method for cleaning tap water piping according to any one of claims 1 to 3, wherein the stop is set to 1 to 2 seconds.   5. The tap water pipe cleaning method according to claim 4, wherein an equivalent flow speed in the tap water flowing in the tap water pipe is set to 0.3 to 0.7 m / sec.   The method for cleaning tap water piping according to claim 4 or 5, wherein an equivalent flow velocity of carbon dioxide flowing in the tap water piping is set to 3 to 8 m / sec.   The intermittent injection time of carbon dioxide gas injected into the tap water pipe is set to 4 seconds for injection and to 2 seconds for stoppage. The tap water pipe according to any one of claims 4 to 6, Cleaning method.   The method for cleaning tap water piping according to any one of claims 1 to 7, wherein carbonated water is continuously supplied into the tap water piping.   The method of cleaning a tap water pipe according to claim 8, wherein the tap water pipe is sucked with a negative pressure from an outlet of the tap water pipe.   The equivalent flow velocity in the tap water pipe flowing through the tap water pipe is 0.3 m / sec or more, the equivalent flow velocity in the saturated carbonated water continuously injected is 0.05 m / sec or more, and the carbon dioxide gas pipe. The equivalent flow rate is 3 m / sec or more, the intermittent injection frequency of carbon dioxide gas is 4 to 5 seconds, the stop is 1 to 2 seconds, and the suction flow rate for sucking in the tap water pipe is 5 m / sec. It sets so that it may become sec or more, The cleaning method of the tap water piping of Claim 9 characterized by the above-mentioned.   11. The tap water pipe cleaning method according to claim 10, wherein the tap water pipe corresponding flow velocity in the tap water pipe is set to 0.3 to 0.7 m / sec.   The method for cleaning tap water pipes according to claim 10 or 11, wherein an in-pipe equivalent flow rate of carbon dioxide gas flowing in the tap water pipes is set to 3 to 8 m / sec.   13. The tap water pipe according to claim 10, wherein the intermittent injection time of the carbon dioxide gas to be injected into the tap water pipe is set to 4 seconds for injection and to 2 seconds for stoppage. Cleaning method.   The tap water pipe cleaning according to any one of claims 10 to 13, wherein a flow rate corresponding to the saturated carbonated water flowing in the tap water pipe is set to 0.05 to 0.25 m / sec. Method.   The method for cleaning a tap water pipe according to any one of claims 10 to 14, wherein a suction flow rate for sucking the tap water pipe is set so that an equivalent flow velocity in the pipe is 5 to 12 m / sec. . In the tap water pipe through which tap water is flowing, a carbon dioxide gas injection device is provided that intermittently injects carbon dioxide that repeats the injection of carbon dioxide and the stop of carbon dioxide injection,
Sandwich that connects the carbon dioxide gas injection device to the tap water pipe, forms a carbon dioxide space by injecting carbon dioxide gas into the tap water pipe, and sandwiches a water mass formed when carbon dioxide injection is stopped by the carbon dioxide gas space Forming structure,
When the water mass flows through the tap water pipe, it adheres to and adheres to the deposit / deposit deposited on the inner wall surface of the pipe, and an impact force is applied to remove the deposit / deposit. Tap water pipe cleaning equipment.   The cleaning device for tap water piping according to claim 16, further comprising a carbonated water producing device for continuously supplying carbonated water into the tap water piping.   18. The tap water pipe cleaning device according to claim 16, further comprising a vacuum generator that sucks the tap water pipe from the discharge port of the tap water pipe with a negative pressure.

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