JP7292710B2 - Ice-making system, ice-making method, and pipeline cleaning method using sherbet-like fluid produced by ice-making system - Google Patents

Description

The present invention relates to an ice-making system, an ice-making method, and a pipeline cleaning method using a sherbet-like fluid produced by the ice-making system, and in particular, an ice-making system and an ice-making system that produce a sherbet-like fluid containing ice particles from salt water. The present invention relates to an ice-making method and a pipeline cleaning method using the sherbet-like fluid.

Pipes that carry fluids, such as water and sewer pipes, transport pipes for sending raw materials and fuel in factories, and domestic drain pipes, may accumulate deposits in the pipes due to long-term use. etc. is attached. In order to prevent problems such as clogging due to adhesion of deposits, such pipes need to be cleaned periodically.

For example, in sewer pipes, filth contained in domestic wastewater and industrial wastewater discharged into the pipe adheres and accumulates on the inner wall of the pipe, and in water supply pipes, minerals contained in tap water and filtration pass through Slime, rust, and the like adhere to the inner wall of the pipeline due to fine foreign matter and organic matter, and accumulate over time.

In recent years, a method of introducing a sherbet-like fluid into a pipeline to be cleaned has attracted attention as a pipeline cleaning method for removing such deposits and foreign matter from the pipeline (for example, Patent Document 1). . In this pipeline cleaning method, a sherbet-like fluid containing fine ice particles in salt water is pressurized and injected into the pipeline to move the fluid. As a result, the ice particles in the fluid collide with the sediment in the pipeline, scrape off the sediment, and are discharged from the pipeline together with the fluid.

Fluid-flowing ducts have adopted various forms according to various uses. For example, it is difficult to clean curved portions and constricted portions of ducts. A cleaning method using a sherbet-like fluid can be easily adapted to various pipe shapes and can appropriately remove deposits. The ice particles forming the fluid are set to have a small average particle size of 0.5 mm or less in order to maintain fluidity in the pipeline.

As an ice-making system for producing sherbet-like fluid from salt water, for example, Patent Document 2 discloses an ice-making device for producing sherbet-like fluid, a storage tank for storing the fluid produced by the ice-making device, and a storage tank. A system is described that includes an agitator for agitating the fluid therein and a return path connecting an outlet provided at the bottom of the storage tank to the brine supply of the ice maker.

In the ice-making system described in Patent Document 2, salt water is first put into a storage tank, and part of the salt water is supplied from the storage tank to the ice-making device through a reflux route. The sherbet-like fluid produced by the ice-making device is stored in a storage tank, ice particles having a lower specific gravity than the salt water float on the salt water, and the salt water is stored at the bottom of the storage tank. By repeating the reflux so as to supply the salt water at the bottom of the storage tank to the ice-making device using the reflux path, the percentage of ice particles in the storage tank increases, and the ice content of the sherbet-like fluid in the storage tank increases. (the ratio of the volume of ice particles to the total volume of sherbet-like fluid in the storage tank) can be increased. Further, by stirring the sherbet-like fluid in the storage tank with a stirring device, it is possible to prevent the ice particles from being combined with each other.

Japanese Patent No. 4653921 JP 2010-71484 A

The sherbet-like fluid used for pipe cleaning is a fluid with a high ratio of solid ice particles to salt water, specifically a fluid with a high ice content, in order to enhance the effect of scraping off deposits in the pipe A sherbet-like fluid of 70% or more is required.

However, in the ice-making system described in Document 2, when the ice content increases, ice particles stirred by the stirring device flow into the reflux path together with the salt water and enter the ice-making device, causing problems such as clogging in the pipes. may occur.

In order to avoid such a situation, when the ice content becomes high, the agitation of the sherbet-like fluid is stopped to sufficiently separate the ice particles and the salt water in the storage tank. It becomes impossible to keep the particle size of the ice particles small due to the bonding between the particles. Therefore, it is necessary to separately prepare a tank equipped with a stirrer, transfer the sherbet-like fluid having a high ice content to this tank, and stir the fluid, resulting in an increase in the size of the equipment.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an ice-making system and an ice-making method capable of producing a sherbet-like fluid with a high ice content without enlarging the equipment, and the sherbet-like fluid. The object of the present invention is to provide a method for cleaning pipelines.

The invention according to claim 1 for achieving the above object is
an ice-making device for cooling salt water to produce a sherbet-like fluid containing ice particles;
a storage tank for storing the sherbet-like fluid produced by the ice making device;
a stirring device for stirring the sherbet-like fluid in the storage tank;
an ice making system comprising a reflux path for returning the fluid discharged from the storage tank to the storage tank via the ice making device,
The return path includes an ice particle separation mechanism for separating ice particles from the fluid discharged from the storage tank and extracting salt water, pressure-feeding means for sending the extracted salt water to the ice making device, and the ice particle separation mechanism. an ice particle return mechanism that returns the ice particles separated by the storage tank ,
The ice particle separation mechanism has a separation filter that is provided at or near the fluid discharge port of the storage tank and separates the ice particles from the sherbet-like fluid,
The ice particle return mechanism includes pressure applying means for applying fluid pressure in a direction opposite to the flow direction of the return path to the ice particles deposited on the separation filter,
The separation filter has a cylindrical shape and is provided in a hopper-type discharge portion that is formed in the storage tank and protrudes downward so that ice particles adhere to the outer peripheral surface,
The final ice content of the sherbet-like fluid in the storage tank is 70% or more .
Further, the invention according to claim 2 is
an ice-making device for cooling salt water to produce a sherbet-like fluid containing ice particles;
a storage tank for storing the sherbet-like fluid produced by the ice making device;
a stirring device for stirring the sherbet-like fluid in the storage tank;
an ice making system comprising a reflux path for returning the fluid discharged from the storage tank to the storage tank via the ice making device,
The return path includes an ice particle separation mechanism for separating ice particles from the fluid discharged from the storage tank and extracting salt water, pressure-feeding means for sending the extracted salt water to the ice making device, and the ice particle separation mechanism. an ice particle return mechanism that returns the ice particles separated by the storage tank,
The ice particle separation mechanism has a separation filter that is provided at or near the fluid discharge port of the storage tank and separates the ice particles from the sherbet-like fluid,
The separation filter has a substantially truncated cone shape or a columnar shape, and is provided to protrude downward from a discharge portion formed at the bottom of the storage tank, and the extracted salt water is provided around the separation filter. A pipeline is provided to circulate,
The ice particle return mechanism includes a pipe that connects the downstream end of the separation filter and the bottom of the storage tank, and pressure applying means that is provided in the pipe and injects the fluid in the storage tank toward the separation filter. and
The final ice content of the sherbet-like fluid in the storage tank is 70% or more.

According to this configuration, the sherbet-like fluid having a high ice content can be produced by repeatedly refluxing the salt water stored in the storage tank using the reflux path. In addition, when the ice content of the sherbet-like fluid in the storage tank becomes high, the sherbet-like fluid in the storage tank is stirred by the agitator to prevent the ice particles from binding to each other, and the ice particles are added to the reflux path. The provided ice particle separation mechanism can separate the ice particles from the sherbet-like fluid discharged from the storage tank and supply the extracted salt water to the ice making device. As a result, while stirring the sherbet-like fluid in one storage tank, the ice content of the sherbet-like fluid stored in this storage tank can be increased. A sherbet-like fluid with a high ice ratio can be produced.

According to this configuration, the ice particles separated in the return path are returned to the storage tank by the ice particle return mechanism, thereby preventing the ice particles from accumulating in the ice particle return mechanism and storing the salt water while maintaining the extraction performance of the salt water. Since the ice content in the tank can be increased, a sherbet-like fluid with a high ice content can be efficiently produced.

According to this configuration, the ice particles deposited on the separation filter can be removed by the pressure application means and returned to the storage tank, so that a sherbet-like fluid with a high ice content can be efficiently produced with a simple structure. can be done.
Further, according to this configuration, the fluid in the storage tank can be a sherbet-like fluid suitable for cleaning the pipeline.

The invention according to claim 3 is the ice making system according to claim 1 or 2 ,
a circulation pipe that connects an outlet and an inlet formed in the storage tank without passing through the ice-making device; and a circulation path having means.

According to this configuration, when the ice content of the sherbet-like fluid in the storage tank increases, the sherbet-like fluid can be stirred by the stirring device and circulated through the circulation path. When maintaining the fluidity of a sherbet-like fluid with a high ice content using only a stirring device, it is necessary to increase the stirring speed sufficiently in order to eliminate unstirred regions. may melt. By circulating the sherbet-like fluid through the circulation path along with stirring, it is possible to maintain the fluidity of the sherbet-like fluid while suppressing an increase in stirring speed and preventing ice particles from melting.

The invention according to claim 4 is the ice making system according to any one of claims 1 to 3 ,
The ice making device
a cylindrical cooling drum whose inner peripheral surface is cooled by a heat exchange medium;
an auger screw disposed inside the cooling drum and having a helical blade on the cylindrical outer peripheral surface for scraping off ice adhering to the inner peripheral surface of the cooling drum;
an injection port provided at one end of the cooling drum for injecting salt water between the inner peripheral surface of the cooling drum and the outer peripheral surface of the auger screw;
a discharge port provided at the other end of the cooling drum for discharging a sherbet-like fluid containing ice particles conveyed by the auger screw;
characterized by comprising

According to this configuration, the salt water injected from the injection port is cooled by the cooling drum, and the ice adhering to the inner peripheral surface of the drum is scraped off by the auger screw to generate a sherbet-like fluid containing ice particles, It can be discharged from the discharge port.

The invention according to claim 5 is
An ice-making method for producing a sherbet-like fluid containing ice particles using the ice-making system according to any one of claims 1 to 4 ,
a reflux step of repeatedly refluxing the salt water stored in the storage tank using the reflux path;
a stirring step of stirring the sherbet-like fluid in the storage tank with the stirring device;
including
The ice content of the sherbet-like fluid in the storage tank is set to 70% or more by repeating the refluxing step a plurality of times while performing the stirring step.

According to this configuration, when the ice content of the sherbet-like fluid in the storage tank increases, the sherbet-like fluid in the storage tank is agitated by the agitator to prevent the ice particles from binding to each other. An ice particle separation mechanism provided in the reflux path can separate ice particles from the sherbet-like fluid discharged from the storage tank and supply the extracted salt water to the ice making device. As a result, it is possible to produce a sherbet-like fluid having an ice content of 70% or more while preventing problems such as clogging with ice particles.

The invention according to claim 6 is a pipeline cleaning method using the sherbet-like fluid produced by the ice making system according to any one of claims 1 to 4 ,
a step of taking out a part of the sherbet-like fluid from a tank containing the fluid and measuring the ice content;
Based on the measurement results, the ice content of the sherbet-like fluid in the tank is adjusted as necessary so that the ice content of the sherbet-like fluid is within a predetermined target ice content range. process and
and a step of cleaning the pipeline using a sherbet-like fluid within the range of the target ice content.

According to this configuration, when cleaning the pipeline, the ice content of the sherbet-like fluid generated by the ice-making system is measured, and the ice content is adjusted to be within the range of the target ice content, thereby making it more suitable for cleaning. Sherbet-like fluid can be used.

According to the ice-making system and ice-making method of the present invention, a sherbet-like fluid with a high ice content can be produced by repeatedly refluxing the salt water stored in the storage tank using the reflux path. In addition, by separating the ice particles from the sherbet-like fluid by the ice particle separation mechanism provided in the reflux path and extracting the salt water, the sherbet-like fluid is stirred in one storage tank while the sherbet-like fluid is stirred. Since the ice content of the sherbet-like fluid stored in the apparatus can be increased, the sherbet-like fluid having a high ice content can be produced without enlarging the equipment. Further, according to the pipeline cleaning method of the present invention, the pipeline can be appropriately cleaned using the sherbet-like fluid produced by this ice making system.

1 is a block diagram of an ice making system that is an embodiment of the present invention; FIG. FIG. 2 is a partial cross-sectional view schematically showing a part of the ice making device; FIG. 4 is a partial cross-sectional view schematically showing another example of the ice making device; Explanatory drawing which shows the ice particle separation mechanism and the ice particle return mechanism in an ice-making system. FIG. 4 is an explanatory diagram showing another example of an ice particle separation mechanism and an ice particle return mechanism in an ice making system; Sectional drawing which shows typically other Example of a storage tank and a stirring apparatus. Explanatory drawing of the measuring means of the ice content rate of sherbet-like fluid. FIG. 2 is a cross-sectional view schematically showing a pipeline cleaning system using a sherbet-like fluid;

FIG. 2 is a block diagram of an ice making system that is an embodiment of the present invention of FIG. 1; The ice-making system 10 is a system for generating a sherbet-like fluid 12 containing ice particles 14 for cleaning pipelines such as sewage pipes, and includes an ice-making device 20, a storage tank 30, an agitating device 35, and a A first reflux pipe 41 , a second reflux pipe 42 , and a circulation pipe 52 are provided. The first return pipe 41 and the second return pipe 42 are pipes that connect the ice making device 20 and the storage tank 30, respectively. It constitutes a reflux path 40 through which salt water stored in the tank 30 is refluxed. The reflux path 40 is provided with a separation filter (ice particle separation mechanism) 44 , an ice particle return mechanism 46 , and a pump (pump means) 43 .

The ice making device 20 includes a refrigeration circuit 21, a cooling drum 22, and an auger screw 26 arranged inside the cooling drum 22, as shown in FIGS.

The refrigeration circuit 21 includes a compressor that compresses refrigerant, a condenser, an expansion valve that expands the refrigerant, an evaporator, and a refrigerant pipe 28 through which the refrigerant circulates. The refrigerant circulates through refrigerant pipes 28 forming a closed loop in the refrigeration circuit 21 and undergoes thermal cycles of compression, condensation, expansion, and evaporation.

As shown in FIG. 2, the cooling drum 22 is formed in a cylindrical shape having an inner cylinder 22A and an outer cylinder 22B integrated with the inner cylinder 22A. A part of a refrigerant pipe 28 (hereinafter referred to as a cooling pipe 24) that constitutes the evaporator of the refrigerating circuit 21 is wound around the outer peripheral surface of the inner cylinder 22A. The cooling pipe 24 and the inner cylinder 22A are made of a material with high thermal conductivity, and the outer cylinder 22B is made of a material with low thermal conductivity. An inlet 23a for injecting salt water into the inner cylinder 22A is formed at one end of the cooling drum 22 (the lower end of the cooling drum 22 extending vertically in the illustrated example), and the other end (the illustrated example A discharge port 23b is formed in the upper end portion).

The auger screw 26 has a cylindrical screw body 26a and a rotary blade (spiral blade) 26b spirally provided on the outer peripheral surface of the screw body 26a. The auger screw 26 is driven to rotate inside the cooling drum 22 by a drive mechanism 27 provided on one end side, scrapes off the ice adhering to the inner peripheral surface 23c of the cooling drum 22, and conveys it to the outlet 23b. In this embodiment, an inlet 23a and an outlet 23b of the cooling drum 22 are provided in the area where the rotary blade 26b of the auger screw 26 is arranged.

In the ice making device 20, the salt water injected into the cooling drum 22 from the injection port 23a and the refrigerant flowing through the cooling pipe 24 are heat-exchanged in the cooling drum 22, thereby cooling the salt water into ice. , and adheres to the inner peripheral surface 23c of the cooling drum 22. The adhering ice is scraped off by the rotating blade 26b of the auger screw 26, becomes the sherbet-like fluid 12 containing the ice particles 14, and is discharged from the outlet 23b.

The particle size (major axis) of the ice particles 14 forming the sherbet-like fluid 12 is 5 mm or less, and preferably the average particle size is about 0.01 to 0.5 mm.

FIG. 3 is a partial cross-sectional view schematically showing another example of the ice making device 20. As shown in FIG. The ice making device 20 includes a cooling drum 62 whose inner peripheral surface 63 is cooled by a refrigerant circulating in a refrigerating circuit, a sealing member 61 that seals one end of the cooling drum 62 (upper end in FIG. 3), and a rotating shaft 65 that is pivotally supported by the member 61 and arranged on the central axis of the cooling drum 62 .

The cooling drum 62 is formed in a cylindrical shape having an inner cylinder 62A and an outer cylinder 62B integrated with the inner cylinder 62A. A cooling pipe 64 constituting an evaporator of a refrigerating circuit is wound around the outer peripheral surface of the inner cylinder 62A. The lower surface of the cooling drum 62 serves as a discharge port for discharging the sherbet-like fluid 12 .

The rotating shaft 65 passes through the sealing member 61 and is rotatably supported by the sealing member 61 by a bearing member 61a fitted between the sealing member 61 and the rotating shaft 65 . The rotary shaft 65 is rotated around its axis by a geared motor (not shown) installed above the sealing member 61 . A rotating shaft 65 inside the cooling drum 62 includes a plurality of pipes 66 rotating together with the rotating shaft 65 and having injection holes 66 a at the tips thereof for injecting salt water toward the inner peripheral surface 63 of the cooling drum 62 . A rotary blade 67 that rotates with the blade is attached. A plurality of pipes 66 are arranged on the outer peripheral surface of the rotating shaft 65 at substantially equal intervals and radially extend from the rotating shaft 12 in the radial direction of the vertical drum 11 . The installation position of each pipe 66 is the upper position of the inner cylinder 62A of the cooling drum 62, and the salt water is jetted toward the upper part of the inner peripheral surface of the inner cylinder 62A. A spray nozzle may be used instead of the pipe 66 . The rotary blade 67 has an arm portion extending radially outward from the rotary shaft 65 and a tip end of the arm portion to scrape the sherbet-like ice formed on the inner peripheral surface 63 of the cooling drum 62 . It has a blade to take. The blade portion is formed over substantially the entire length (total height) of the inner cylinder 22 . The gap between the blade portion and the inner cylinder 62A of the cooling drum 62 is preferably about 0.1 mm to 0.2 mm.

A communication hole 67 is formed in the upper portion of the rotating shaft 65 so as to extend in the axial direction within the rotating shaft 65 and communicate with each pipe 66 . The top of the rotating shaft 12 is connected to the first return pipe 41 by a joint member (not shown), and the salt water supplied from the first return pipe 41 into the communication hole 67 is sent to each pipe 66.

In the ice making device 20 shown in FIG. 3, salt water is injected into the cooling drum 22 from each pipe 66 that rotates together with the rotating shaft 65 through the communication hole 67 of the rotating shaft 65 that rotates by the geared motor. , and adheres to the inner peripheral surface 63 of the cooling drum 62 . The adhering ice is scraped off by the blade portion of the rotary blade 67 , becomes the sherbet-like fluid 12 containing the ice particles 14 , is discharged from the bottom side of the cooling drum 62 , and is stored in the storage tank 30 . Note that such an ice making device 20 can be manufactured with reference to, for example, the device described in JP-A-2017-72358. In such an ice making device 20, the ice content rate can be increased as compared with the auger type ice making device shown in FIG.

In the ice-making device 20 shown in FIGS. 2 and 3, the temperature of the inner peripheral surface of the cooling drum can be -30.degree. C. to -60.degree. In addition, since the ice particles 14 produced by the ice making device 20 have a lower salt concentration than the surrounding salt water, the salt water in the sherbet-like fluid 12 discharged from the ice making device 20 is , the salt concentration is higher than that of the salt water supplied to the ice making device 20 . For example, when the sherbet-like fluid 12 with an ice content of about 80% is produced using salt water with a salt concentration of 5% by mass by the method described later, the salt concentration in the salt water is 8 to 10% by mass. can be in a state contained in the ice particles 14 .

The storage tank 30 stores the salt water and the sherbet-like fluid 12 produced by the ice making device 30 . The storage tank 30 has a fluid discharge port 31a, a fluid storage port 31b, an outflow port 32a, and an inflow port 32b. In this embodiment, a hopper-type discharge portion 33 is formed at the bottom of the storage tank 30, and the tip thereof serves as a fluid discharge port 31a. Furthermore, the storage tank 30 has a salt inlet (not shown) at the top.

The stirring device 35 has stirring blades 37 arranged in the storage tank 30 , and drives the stirring blades 37 with a motor 36 to stir the fluid in the storage tank 30 .

The first return pipe 41 has one end connected to the fluid outlet 31 a of the storage tank 30 and the other end connected to the inlet 23 a of the cooling drum 22 of the ice making device 20 . The first outflow port 31 a is formed at or near the bottom of the storage tank 30 . The first return pipe 41 is provided with a pump 43 that causes the fluid in the pipe to flow from the storage tank 30 side toward the ice making device 20 side, and a control valve 49 that opens and closes the flow path of the first return pipe 41 . ing. A control valve 49 is arranged upstream of the pump 43 .

As shown in FIG. 4, the fluid discharge port 31a of the storage tank 30 is provided with a separation filter 44 for separating the ice particles 14 from the sherbet-like fluid 12 and extracting salt water. The separation filter 44 has a mesh smaller than the average particle size of the ice particles 14, and is cylindrical in this embodiment. As shown in FIG. 4, by providing the separation filter 44 over substantially the entire height direction of the hopper-type discharge section 33, it is possible to make the separation filter 44 less likely to be affected by agitation and to cause clogging of the separation filter 44. Ice particles 14 can be properly separated.

The fluid (that is, salt water) from which the ice particles 14 are separated by the separation filter 44 is sent to the ice making device 20 by the pump 43 arranged in the first return pipe 41 .

The separation filter 44 may be provided in the vicinity of the fluid discharge port 31a, for example, in the storage tank 30 near the fluid discharge port 31a or near the downstream of the fluid discharge port 31a. Further, the shape of the separation filter 44 is not limited to this, and may be, for example, a sheet shape with a required thickness. Further, instead of the separation filter 44, for example, a structure in which an ice particle separation mechanism that separates the ice particles 14 and salt water by centrifugal separation is provided in the return path 40 may be employed.

An ice particle return mechanism 46 is provided near the separation filter 44 . The ice particle return mechanism 46 returns the ice particles 14 separated by the separation filter 44 to the storage tank 30. In the present embodiment, the branch pipe 47 branched from the first return pipe 41 and the separation pipe 47 and a fluid supply control valve 45 .

One upstream end of the branch pipe 47 is connected to the first return pipe 41 downstream of the ice particle separation mechanism 44 , and the other downstream end is connected to the return path 40 near the ice particle separation mechanism 44 . be done. In this embodiment, the downstream end of the branch pipe 47 is connected to the discharge portion 33 of the storage tank 30 .

The fluid supply control valve 45 is connected to a control device (not shown) and opens and closes the flow path of the branch pipe 47 at a predetermined timing. In the present embodiment, opening/closing control of the valves 45 and 49 is performed so that the fluid supply control valve 45 is opened when the flow path of the first return pipe 41 is closed by the control valve 49 . The pump 48 pumps the fluid flowing through the branch pipe 47 from the upstream end to the downstream end while the fluid supply valve 45 is open.

In the ice particle return mechanism 46 described above, the control valve 49 is closed, the fluid supply control valve 45 is opened, and the pump 48 is driven, so that the salt water discharged from the fluid discharge port 31a is discharged through the branch pipe 47. to the ice particles 14 deposited on the separation filter 44 . As a result, the ice particles 14 accumulated on the separation filter 44 are applied with fluid pressure in the direction opposite to the flow direction of the return path 40, and the ice particles 14 removed from the separation filter 44 are returned into the storage tank 30. Note that the ice particle return mechanism 46 moves the downstream end of the branch pipe 47 to the separation filter so that the salt water is injected backward from the downstream side (ice making device 20 side) of the separation filter 44 toward the upstream side (storage tank 30 side). 44 may be arranged on the downstream side.

FIG. 5 is a diagram illustrating another example of the separation filter 44 and the ice particle return mechanism 46. As shown in FIG.

The separation filter 44 has a substantially truncated cone shape attached to the discharge part 33 formed at the bottom of the storage tank 30, and is provided with a pipe line 70 for circulating the extracted salt water around it. Note that the shape of the separation filter 44 is not limited to this, and may be cylindrical or polygonal. The salt water in line 70 is sent to ice making device 20 through first reflux line 41 .

The ice particle return mechanism 46 includes a pipe 72 connecting the downstream end of the separation filter 44 and the storage tank 30 , and a pump 73 provided on the pipe 72 . One end of the pipe 72 is connected to the through hole 38 formed in the bottom of the storage tank 30 . In this ice particle return mechanism 46 , the fluid in the storage tank 30 is injected toward the separation filter 44 by the pump 73 , that is, the fluid is reversely injected to the separation filter 44 , thereby depositing ice particles on the separation filter 44 . The frozen ice particles 14 can be returned into the storage tank 30 .

The second return pipe 42 has one end connected to the discharge port 23 b of the cooling drum 22 and the other end connected to the fluid storage port 31 b of the storage tank 30 . A fluid storage port 31 b is provided in the upper portion of the storage tank 30 . The sherbet-like fluid produced by the ice-making device 20 is stored in the storage tank 30 through the second reflux pipe 42 . Although not shown, the second return pipe 42 may be provided with pressure-feeding means such as a pump for pressure-feeding the sherbet-like fluid from the ice making device 20 side to the storage tank 30 side.

The circulation pipe 52 is a pipe that connects the outflow port 32a and the inflow port 32b of the storage tank 30 without passing through the ice making device 20, and a pump (pump means) 53 is arranged in the flow path. . The circulation pipe 52 and the pump 53 constitute a circulation path 50 for circulating the sherbet-like fluid 12 in the storage tank 30 . It should be noted that the circulation path 50 can be configured to be provided with a screw pump, which is pressure-feeding means, instead of the pump 53 .

Furthermore, in the present embodiment, a branch pipe 57 extends from the circulation pipe 52 and is connected to a utilization tank 58 . The branch pipe 57 is provided with a valve 59 for opening and closing the flow path. A valve 55 that opens and closes the flow path of the circulation pipe 52 is provided downstream of the connecting portion of the branch pipe 57 in the circulation pipe 52 .

Next, a method for producing the sherbet-like fluid 12 used for cleaning the pipeline using the ice-making system 10 described above will be described.

First, water is stored in the storage tank 30, salt is introduced from the salt inlet, and salt water is produced by driving the stirring device 35 and stirring (salt water producing step). The salt content in this salt water can be, for example, 3 to 7% by mass. In the salt water generation step, in addition to stirring by the stirring device 35, the salt water in the storage tank 30 is circulated using the circulation path 50 with the valve 59 of the branch pipe 57 closed and the valve 55 of the circulation pipe 52 opened. Thereby, salt water having a uniform salt concentration can be generated early. In addition, in the salt water generation step, the reflux path 40 is in a reflux stop state by closing the fluid discharge port 31a and the valve 49 .

After the salt water is produced, the sherbet-like fluid 12 is produced by the ice making device 20 (ice making step). In this ice-making process, the flow path of the reflux path 40 is set in a flowing state, and a part of the salt water in the storage tank 30 is supplied to the ice-making device 20 by driving the pump 43 to generate the sherbet-like fluid 12. , and the stirring step of driving the stirring device 35 to stir the fluid in the storage tank 30 are performed at the same time.

In the reflux process, the salt water supplied to the ice-making device 20 is cooled while passing through the cooling drum 22, becomes ice-like, adheres to the inner peripheral surface 23c of the cooling drum 22, and is scraped off by the auger screw 26. The sherbet-like fluid 12 containing the ice particles 14 is discharged from the discharge port 23 b of the cooling drum 22 and stored in the storage tank 30 through the second reflux pipe 42 . The ice-making rate of the sherbet-like fluid 12 produced from salt water by the ice-making device 20 (that is, the ice content when salt water containing no ice particles 14 passes through the ice-making device 20 once) is, for example, about 30 to 30%. 60%, preferably about 50-60%.

During the reflux process, in the storage tank 30, the stirring device 35 is driven to stir the sherbet-like fluid 12 in the storage tank 30 (stirring process). By repeating the reflux process a plurality of times while performing the stirring process, the ice content of the sherbet-like fluid 12 in the storage tank 30 gradually increases. At the beginning of the ice-making process, the ice particles 14 float upward in the fluid in the storage tank 30, and salt water accumulates at the bottom. It will be in a state of being accumulated at the bottom of 30 .

In the reflux process, the ice particles 14 mixed in the fluid discharged from the storage tank 30 are separated from the salt water by the separation filter 44 . The salt water that has passed through the separation filter 44 is supplied to the ice making device through the first reflux pipe 41 .

The ice particles 14 deposited on the separation filter 44 are removed from the separation filter 44 by activating the ice particle return mechanism 46 and injecting salt water back into the separation filter 44 via the branch pipe 47 by the pressure of the pump 48. be able to. This reverse injection returns the ice particles 14 adhering to the separation filter 44 into the storage tank 30 . The timing for operating the ice particle return mechanism 46 can be set as appropriate. For example, the amount of ice particles 14 deposited on the separation filter 44 may be detected by a detector (not shown), and the ice particle return mechanism 46 may be activated when the ice particles 14 are deposited in a predetermined amount or more. As another example, the ice particle return mechanism 46 may be operated at predetermined time intervals after the ice content in the storage tank 30 reaches or exceeds a set value. When operating the ice particle return mechanism 46, the circulation through the circulation path 40 can be temporarily stopped.

In the ice-making process, the circulation path 50 may continue to circulate the fluid in the storage tank 30 from the salt water generation process, but after the salt water generation process, the pump 53 may be stopped to stop the flow. . In this case, at the beginning of the ice-making process when the ice content in the storage tank 30 is low, the circulation path 50 is kept in a stopped state, and the ice content in the storage tank 30 reaches a predetermined value or more (for example, 40% or more). At this time, the pump 53 is driven to bring it into circulation, and the sherbet-like fluid 12 is circulated while performing the stirring process.

In this way, in the ice making process, the reflux process, the stirring process, and the circulation process of moving the sherbet-like fluid 12 through the circulation path 50 are simultaneously performed, and by repeating the reflux process, the ice content in the storage tank 30 is increased. The sherbet-like fluid 12, specifically, the sherbet-like fluid 12 having an ice content of 70% or more, preferably 75 to 90%, more preferably 80 to 85%, is produced.

The particle size (major axis) of the ice particles forming the sherbet-like fluid 12 is 5 mm or less, and preferably the average particle size is about 100 μm to 300 μm. Here, the average particle size of about 100 μm to 300 μm means that the particle size of the ice particles, which accounts for at least 70 to 80% of the total mass of the ice particles, is in the range of about 100 μm to 300 μm.

After the ice-making process is finished, the sherbet-like fluid 12 is maintained in a fluid state by agitation by the agitator 35 and circulation by the circulation path 50 .

According to the ice making system 10 described above, the sherbet-like fluid 12 with a high ice content can be produced by repeatedly refluxing the salt water stored in the storage tank 30 using the reflux path 40 . Further, when the ice content of the sherbet-like fluid 12 becomes high, the sherbet-like fluid in the storage tank 30 is agitated by the agitator 35 and circulated through the circulation path 50 to prevent the sherbet-like flow in the storage tank 30. Bonding between ice particles 14 of body 12 can be prevented.

In general, when maintaining the fluidity of the sherbet-like fluid 12 with a high ice content only by the stirring device 35, it is necessary to sufficiently increase the stirring speed. As a result, the temperature of the fluid rises and the ice particles 14 melt. However, by circulating the sherbet-like fluid 12 through the circulation path 50 along with stirring, the fluidity of the sherbet-like fluid 12 is improved while suppressing the increase in stirring speed and preventing the ice particles 14 from melting. can be maintained.

In the ice-making system 10 described above, the salt water extracted by separating the ice particles 14 from the sherbet-like fluid 12 discharged from the storage tank is supplied to the ice-making device 20 by the separation filter 44 provided in the return path 40 . Therefore, while the sherbet-like fluid 12 is stirred in one storage tank 30, the ice content of the sherbet-like fluid 12 stored in this storage tank 30 can be increased. As a result, the sherbet-like fluid 12 with a high ice content can be produced without enlarging the equipment.

Furthermore, the ice particle return mechanism 46 removes the ice particles 14 deposited on the separation filter 44 using fluid pressure and returns it to the storage tank 30, so that sherbet with a simple structure and high ice content can be efficiently obtained. shaped fluid 12 can be generated.

In addition, in the salt water generation step, the salt water stored in the storage tank 30 can be at a temperature higher than 0° C., such as room temperature. By continuing the ice-making process using the reflux path 40 after the salt water generation process, the produced sherbet-like fluid 12 is supplied into the storage tank 30, and the liquid in the storage tank 30 is gradually cooled. By repeating this, the liquid in the storage tank 30 containing salt enters a supercooled state in which the temperature is lower than 0° C. (for example, −5° C.). In this way, the liquid in the storage tank 30 is in a supercooled state, so that the sherbet flow state 12 in the storage tank 30 can maintain the ice particles 14 without melting.

The sherbet-like fluid 12 produced using the ice-making system 10 can be used via the branch pipe 57 by closing the valve 55 of the circulation pipe 52 and opening the valve 59 of the branch pipe 57 as necessary. It is transferred to a tank 58 and transported to a cleaning site by a construction vehicle equipped with this utilization tank 58 . The utilization tank 58 is provided with a stirrer 58a for constantly stirring the sherbet-like fluid 12 in the utilization tank 58 . Furthermore, without using the branch pipe 57 and the utilization tank 58, the storage tank 30 including the stirring device 35 and the circulation path 50 are separated from the ice making system 10, and these are mounted on a construction vehicle and transported to the pipeline cleaning site. can be configured. In addition, a construction vehicle equipped with the ice making system 10 can be used to transport the entire ice making system 10 to the pipeline cleaning site. The sherbet-like fluid 12 with an ice content of 70% or more is preferably constantly stirred until the cleaning operation is performed, and the stirring device 35 is kept stirring for at least 15 minutes or more so as not to stop stirring. more preferably 5 minutes or longer, more preferably 1 minute or longer.

FIG. 6 shows another embodiment of the storage tank 30 and agitator 35 used in the ice making system 10. As shown in FIG. The storage tank 30 constitutes a tank system capable of storing the sherbet-like fluid 12 together with the stirring device 35 and the ice content measuring means 74 described later.

The storage tank 30 is formed in a substantially cylindrical shape as a whole, and is provided with a fluid storage port 31b, an inflow port 32b, and a salt inlet 34 at the top of the storage tank 30 in the installed state, and a fluid storage port 31b at the bottom. An outlet 31a and an outlet 32a are provided. Note that the illustration of the fluid discharge port 31a is omitted in FIG.

A hopper 32 is connected to the outflow port 32a, and a circulation pipe 52 is connected to the downstream end of the hopper 32. Inside the circulation pipe 52, a screw pump 54 is provided as pressure feeding means. When the driving device 56 connected to the screw 54 is turned on, the screw pump 54 rotates and pressure-feeds the fluid flowing into the hopper 32 through the circulation pipe 52 to the inlet 32b.

By configuring the circulation path 50 using the hopper 32 and the screw pump 54 as in the example shown in FIG. 6, the sherbet-like fluid 12 with a high ice content can be circulated more appropriately. Further, by mounting the screw pump 54 on the fluid injection device 88 together with the storage tank 30, the screw pump 54 can be used as a pumping means for pumping the sherbet-like fluid 12 into the injection communicating pipe in the pipeline cleaning work. can be used as

In addition, the representative speed of stirring of the stirring device 35 used in the storage tank 30 (the speed of the part where the stirring speed is the fastest, that is, the speed of the outermost radial direction of the stirring blade) is about 0.1 to 0.2 m / s. is preferably

An ice content measuring means 74 for measuring the ice content of the sherbet-like fluid 12 is provided in the pipe 50A on the downstream side of the screw pump 54 . As shown in FIG. 7, the ice content measuring means 74 of the present embodiment includes a bypass pipe 76 connected to the pipe 50A, and an upstream end and a downstream end of the bypass pipe 76 that can open and close the pipe. It has valves 75B and 75C and a piston-like movable member 77 that changes the volume of the bypass pipe 76 . 7, only the sherbet-like fluid 12 in the area between the two valves 75B and 75C of the bypass pipe 76 is shown for easy understanding.

The movable member 77 is arranged between the valves 75B and 75C, and has a columnar filter portion 77a that can slide on the inner peripheral surface of the bypass pipe 76 and a rod-like portion 77b for moving the columnar filter portion 77a. The filter portion 77a is set to have a mesh size smaller than the average particle diameter of the ice particles 14, so that only salt water can pass through.

In this ice content measuring means 74, as shown in FIG. 7A, a valve 75A provided in the pipe 50A is closed to fill the bypass pipe 76 with the sherbet-like fluid 12, and then the valves 75B and 75C are closed. close. Next, as shown in FIG. 7B, by moving the movable member 77, one area partitioned by the filter portion 77a is filled only with the ice particles 14, and salt water is discharged to the other area. By measuring the amount of movement of the movable member 77 at this time, the ice content is indirectly measured. Note that the relationship between the amount of movement of the movable member 77 in the bypass pipe 76 and the ice content can be set based on the results of experiments performed in advance. Further, by making the bypass pipe 76 a transparent pipe and attaching a visible scale, it is possible to easily visually recognize the amount of movement of the filter 77a that has moved in this pipe.

As an example, when the target ice content rate (predetermined target ice content rate) of the sherbet-like fluid is set to 80 to 85%, the ice making device 20 The ice content can be further increased by Further, when the measured ice content is higher than the target value, salt water is supplied into the storage tank 30 from the salt water pipe 78 connected to the storage tank 30 to lower the ice content. Alternatively or simultaneously, the ice content may be reduced by increasing the stirring speed of the stirring device 35 to melt the ice particles 14 .

Next, a pipeline cleaning system 80 that cleans the inside of the pipeline using the sherbet-like fluid 12 generated by the ice making system 10 will be described.

FIG. 8 is a cross-sectional view schematically showing an example of the channel cleaning system 80. As shown in FIG. The pipe cleaning system 80 includes a water main pipe 82, which is an example of a pipe to be cleaned, a plurality of branch pipes 84 and 85 communicating between the water main pipe 82 and the outside, and a section upstream of the water main pipe 82 to be cleaned. Water control valves 86a and 86b for closing the side and downstream opening ends, respectively, a fluid injection device 88 for pressurizing and injecting the fluid 12 into the water supply main pipe 82, and a recovery tank 89 for recovering the fluid 12. and

The water supply main pipe 82 is buried at a predetermined depth from the ground, and a plurality of water control valves 86a and 86b are installed in the middle of the pipeline. During cleaning, by closing the water control valves 86a and 86b located at both ends of the cleaning target section 90 of the water main pipe 82, the flow of clean water 98 in the cleaning target section 90 can be stopped.

The branch pipes 84 and 85 are pipelines branching from the water main pipe 82 and extending to the ground, and are provided in plurality at predetermined intervals in the extending direction of the water main pipe 82 . The branch pipes 84 and 85 are used for inspection of the main water supply pipe 82, etc., and a fire hydrant or mud drain pipe (not shown) is attached through water stop valves 91 and 92.

Of the branch pipes 84 and 85, the branch pipe 84 positioned on one end side of the section 90 to be cleaned is used as an injection pipe for injecting the sherbet-like fluid 12, and the branch pipe 85 positioned on the other end side is , is used as a discharge pipe for discharging the sherbet-like fluid 12 . In the example shown in FIG. 8, branch pipes 84 and 85 protrude into recesses 94 and 95 dug from the ground to a predetermined depth. , a connection pipe 96 for injection and a connection pipe 97 for discharge.

The fluid injection device 88 includes a storage tank 30 or a utilization tank 58 for containing the sherbet-like fluid 12, and pressure-feeding means (for example, a screw pump, etc.) for pressure-feeding the fluid 12 in the tank into the injection communication pipe. Prepare. In this embodiment, the ice making system 10 is mounted on a construction vehicle for cleaning, and the fluid injection device 88 includes the storage tank 30, the screw pump 54, the ice content measuring means 74, and the like shown in FIG. It consists of a tank system with The fluid injection device 88 is disposed on the ground, and the sherbet-like fluid 12 discharged from the fluid injection device 88 is pressurized and injected into the water supply main pipe 20 via the connecting pipe 96 and the branch pipe 84 . In this embodiment, as shown in FIG. 6, the flow path is switched by a three-way valve 55A provided in the circulation pipe 52, and the sherbet-like fluid 12 pressure-fed by the screw pump 54 is connected via the three-way valve 55A. can be injected into the connected tube 96 .

The collection tank 89 is a tank for collecting the washed sherbet-like fluid 12, and is installed at the downstream end of the connection pipe 97, which is a pipe for discharge.

In the pipeline cleaning system 80 described above, the water main 82 is cleaned by the following method.

First, as shown in FIGS. 6 and 7, the ice content rate of the sherbet-like fluid 12 in the storage tank 30 is measured by the ice content rate measuring means 74 provided with the fluid injection device 88 arranged on the ground. . If it is judged from the measurement result that the ice content exceeds the range of the target ice content, the ice content is adjusted. For example, when the ice content is low, the ice making device 20 is operated to increase the ice content in the storage tank 30, and when the ice content is high, salt water is supplied from the salt water pipe 78 to the storage tank 30. is supplied to lower the ice content, the sherbet-like fluid 12 is adjusted within the range of the target ice content.

Next, the fluid injection device 88 is connected to the branch pipe 84 via the water stop valve 91 and the connection pipe 96, and the recovery tank 89 is connected to the branch pipe 85 via the water stop valve 92 and the connection pipe 97. Connecting. Also, the water control valves 86a and 86b are closed to stop the flow of clean water 98 in the section 90 to be cleaned. When adjusting the ice content of the sherbet-like fluid 12, these operations can be performed in parallel.

Next, the water stop valves 91 and 92 are opened, the fluid injection device 88 is operated, and the sherbet-like fluid 12 is pressurized and injected into the section 90 to be cleaned. At this time, the clean water 98 remaining in the section 20 to be cleaned is pushed downstream by the injection of the sherbet-like fluid 12 and discharged.

The sherbet-like fluid 12 is pressurized and injected so as to fill the cross section of the pipeline in at least a part of the section 90 to be cleaned. In the present embodiment, the sherbet-like fluid 12 is filled over the entire area to be cleaned 90 and pressurized so as to move in the area to be cleaned 90 at a speed of, for example, about 0.3 to 1.0 m/s. injecting. The moving speed may be constant, or may be changed within a predetermined range. Deposits adhere to the inner wall of the water supply main pipe 82 that has been used for many years, and the movement of the sherbet-like fluid 12 scrapes off the adhered deposits and cleans the inside of the pipe. be done. By setting the ice content of the sherbet-like fluid 12 to 70% to 90%, it is possible to clean the inside of the long-distance pipeline while scraping off deposits. For the water main pipe 82, for example, when the inner diameter is about 100 to 400 mm, the length of the cleaning target section 16 can be about 300 to 4000 m.

The sherbet-like fluid 12 that has passed through the section 90 to be cleaned and the removed sediments and the like are discharged into the collection tank 89 via the branch pipe 85 and the connecting pipe 97 . Although not shown, a water quality monitor is connected to the discharge pipe, and the water quality monitor monitors the turbidity, temperature, and internal pressure of the discharged sherbet-like fluid 12 .

When the injection of the sherbet-like fluid 12 necessary for washing is completed, the water stop valve 91 is closed. Next, by opening the water control valve 86a on the upstream side and allowing the clean water 98 to flow into the cleaning target section 90, the sherbet-like fluid 12 in the clean water main pipe 82 is washed away and discharged from the branch pipe 85 to the outside. . Such flushing of the cleaning target section 90 with clean water 98 is performed until a predetermined water quality is obtained by the water quality monitoring device. After the predetermined water quality is confirmed, the water stop valve 92 is closed and the water control valve 86b is opened.

In this pipeline cleaning system 80 , the sherbet-like fluid 12 removes the attached deposits and discharges them together with the sherbet-like fluid 12 , thereby appropriately cleaning. By using the sherbet-like fluid 12 with a high ice content, the force to scrape off the sediment is increased to enhance the cleaning power, and the removed sediment is properly removed by the solid ice particles 14 without being retained in the pipeline. can be discharged to

In addition, before pouring the sherbet-like fluid 12 into the water supply main pipe 82, the ice content is measured, and the cleaning effect can be enhanced by adjusting the target ice content.

For example, if the place where the sherbet-like fluid 12 is generated is away from the washing site, the ice particles 14 may melt while the sherbet-like fluid 12 is being conveyed, and the ice content may decrease. , the sherbet-like fluid 12 having an ice content higher than the target value may be generated. In such a case, the ice content is measured at the washing site, and if the ice content is still higher than the target value, salt water is supplied to bring it within the target range, so that the sherbet-like fluid 12 liquidity can be secured.

In addition, the pipeline to be cleaned is not limited to the water supply pipe, and may be a sewage pipe, an industrial/farm pipe, or the like. When cleaning a sewer pipe, for example, for a sewer pipe with an inner diameter of about 150 to 600 mm, the section to be cleaned can be about 15 to 300 m, and the sherbet-like fluid 12 has an ice content of 70% or more. As a result, it is possible to appropriately transport and discharge the removed deposits while maintaining the ability to scrape off the ice particles in the section to be cleaned.

It should be noted that the present invention is not limited to the above-described embodiments and modifications, and various modifications can be made without departing from the scope of the invention.

REFERENCE SIGNS LIST 10 ice-making system 20 ice-making device 21 refrigerating circuit 22 cooling drum 24 cooling pipe 26 auger screw 28 refrigerant pipe 30 storage tank 35 stirring device 40 reflux path 41 first reflux pipe 42 second reflux pipe 44 ice particle separation mechanism 46 ice particle return mechanism 48 pump (pressure applying means)
50 circulation path 52 circulation pipe 58 utilization tank 80 pipe cleaning system

Claims (6)

an ice-making device for cooling salt water to produce a sherbet-like fluid containing ice particles;
a storage tank for storing the sherbet-like fluid produced by the ice making device;
a stirring device for stirring the sherbet-like fluid in the storage tank;
an ice making system comprising a reflux path for returning the fluid discharged from the storage tank to the storage tank via the ice making device,
The return path includes an ice particle separation mechanism for separating ice particles from the fluid discharged from the storage tank and extracting salt water, pressure-feeding means for sending the extracted salt water to the ice making device, and the ice particle separation mechanism. an ice particle return mechanism that returns the ice particles separated by the storage tank ,
The ice particle separation mechanism has a separation filter that is provided at or near the fluid discharge port of the storage tank and separates the ice particles from the sherbet-like fluid,
The ice particle return mechanism includes pressure applying means for applying fluid pressure in a direction opposite to the flow direction of the return path to the ice particles deposited on the separation filter,
The separation filter has a cylindrical shape and is provided in a hopper-type discharge portion that is formed in the storage tank and protrudes downward so that ice particles adhere to the outer peripheral surface,
An ice making system , wherein the final ice content of the sherbet-like fluid in the storage tank is 70% or more . an ice-making device for cooling salt water to produce a sherbet-like fluid containing ice particles;
a storage tank for storing the sherbet-like fluid produced by the ice making device;
a stirring device for stirring the sherbet-like fluid in the storage tank;
an ice making system comprising a reflux path for returning the fluid discharged from the storage tank to the storage tank via the ice making device,
The return path includes an ice particle separation mechanism for separating ice particles from the fluid discharged from the storage tank and extracting salt water, pressure-feeding means for sending the extracted salt water to the ice making device, and the ice particle separation mechanism. an ice particle return mechanism that returns the ice particles separated by the storage tank ,
The ice particle separation mechanism has a separation filter that is provided at or near the fluid discharge port of the storage tank and separates the ice particles from the sherbet-like fluid,
The separation filter has a substantially truncated cone shape or a columnar shape, and is provided to protrude downward from a discharge portion formed at the bottom of the storage tank, and the extracted salt water is provided around the separation filter. A pipeline is provided to circulate,
The ice particle return mechanism includes a pipe that connects the downstream end of the separation filter and the bottom of the storage tank, and pressure applying means that is provided in the pipe and injects the fluid in the storage tank toward the separation filter. and
An ice making system , wherein the final ice content of the sherbet-like fluid in the storage tank is 70% or more . a circulation pipe that connects an outlet and an inlet formed in the storage tank without passing through the ice-making device; 3. An ice making system according to claim 1 or 2 , characterized by comprising a circulation path having means. The ice making device
a cylindrical cooling drum whose inner peripheral surface is cooled by a heat exchange medium;
an auger screw disposed inside the cooling drum and having a helical blade on the cylindrical outer peripheral surface for scraping off ice adhering to the inner peripheral surface of the cooling drum;
an injection port provided at one end of the cooling drum for injecting salt water between the inner peripheral surface of the cooling drum and the outer peripheral surface of the auger screw;
a discharge port provided at the other end of the cooling drum for discharging a sherbet-like fluid containing ice particles conveyed by the auger screw;
The ice making system according to any one of claims 1 to 3 , characterized by comprising: An ice-making method for producing a sherbet-like fluid containing ice particles using the ice-making system according to any one of claims 1 to 4 ,
a reflux step of repeatedly refluxing the salt water stored in the storage tank using the reflux path;
a stirring step of stirring the sherbet-like fluid in the storage tank with the stirring device;
including
An ice making method, wherein the ice content of the sherbet-like fluid in the storage tank is increased to 70% or more by repeating the refluxing step a plurality of times while performing the stirring step. A pipeline cleaning method using the sherbet-like fluid produced by the ice making system according to any one of claims 1 to 4 ,
a step of taking out a part of the sherbet-like fluid from a tank containing the fluid and measuring the ice content;
Based on the measurement results, the ice content of the sherbet-like fluid in the tank is adjusted as necessary so that the ice content of the sherbet-like fluid is within a predetermined target ice content range. process and
and a step of cleaning the pipeline using a sherbet-like fluid within the range of the target ice content.

Images