JP2020159640A - Ice making system, ice making method, and pipeline cleaning method using sherbet-like fluid generated by ice making system - Google Patents

Abstract

To provide an ice making system and an ice making method capable of generating sherbet-like fluid high in water content of ice particles of small particle diameter without upsizing a facility, and a pipeline cleaning method using sherbet-like fluid.SOLUTION: An ice making system 10 includes: an ice making device 20 generating sherbet-like fluid 12 containing ice particles 14 by cooling salt water; a storage tank 30 storing the generated sherbet-like fluid 12; a stirring device 35 stirring fluid in the storage tank 30; and a circulation line 40 circulating fluid discharged from the storage tank 30 back to the storage tank 30 via the ice making device 29. The circulation line 40 is provided with: a separation filter 44 which separates the ice particles 14 from the fluid discharged from the storage tank 30 and extracts salt water; and a pump 43 feeding the extracted salt water to the ice making device 20. By repeatedly circulating the salt water by the circulation line 40, the sherbet-like fluid of high ice content suited to pipeline cleaning can be generated.SELECTED DRAWING: Figure 1

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 that produces 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 flow fluids, such as water supply pipes and sewer pipes, transport pipes that send raw materials and fuel in factories, and drainage pipes in homes, are deposited in the pipes after long-term use. Etc. adhere. In such a pipeline, it is necessary to perform regular cleaning in order to prevent problems such as clogging due to adhesion of sediment.

For example, in sewer pipes, domestic wastewater discharged into the pipes and filth contained in industrial wastewater adhere to and accumulate on the inner wall of the pipes, and in water pipes, minerals and filters contained in tap water pass through. Due to fine foreign matter and organic substances, slime and rust adhere to the inner wall of the pipeline and accumulate over time.

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

Various forms of the pipeline through which the fluid flows are adopted according to various uses. For example, it is difficult to clean a bent portion or a narrowed portion of the pipeline. The cleaning method using a sherbet-like fluid can be easily adapted to various pipeline shapes, and deposits can be appropriately removed. The ice particles constituting the fluid are set to a small particle size of 0.5 mm or less in order to maintain the fluidity in the pipeline.

As an ice making system for producing a sherbet-like fluid from salt water, for example, Patent Document 2 describes an ice making device for producing a sherbet-like fluid, a storage tank for storing the fluid generated by the ice making device, and a storage tank. A system including a stirrer for agitating the fluid inside and a recirculation path connecting a discharge port provided at the bottom of a storage tank and a salt water supply port of an ice making device is described.

In the ice making system described in Patent Document 2, first, salt water is put into a storage tank, and a part of the salt water is supplied from this storage tank to the ice making device by a reflux route. The sherbet-like fluid generated by the ice making device is stored in a storage tank, ice particles having a specific gravity smaller than that of salt water are floated in salt water, and salt water is accumulated at the bottom of the storage tank. By repeating 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 proportion of ice particles in the storage tank increases, and the ice content of the sherbet-like fluid in the storage tank increases. (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 the stirring device, it is possible to prevent the ice particles from binding to each other.

Japanese Patent No. 4653921 Japanese Unexamined Patent Publication No. 2010-71484

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

However, in the ice making system described in Cited Document 2, when the ice content becomes high, the ice particles agitated by the agitator flow into the ice making device together with the salt water and enter the ice making device, resulting in a problem such as clogging in the piping. May occur.

In order to avoid such a situation, when the ice content becomes high, if the stirring of the sherbet-like fluid is stopped and the ice particles and the salt water are sufficiently separated in the storage tank, the ice The particles are bonded to each other and the particle size of the ice particles cannot be kept small. Therefore, it is necessary to separately prepare a tank equipped with a stirring device and transfer a sherbet-like fluid having a high ice content to this tank for stirring, resulting in an increase in 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 having a high ice content without enlarging the equipment, and the sherbet-like fluid. The purpose is to provide the pipeline cleaning method used.

The invention according to claim 1 for achieving the above object
An ice maker that cools salt water to produce sherbet-like fluid containing ice particles,
A storage tank for storing the sherbet-like fluid generated by the ice making device, and
A stirring device that stirs the sherbet-like fluid in the storage tank,
In an ice making system provided with a reflux path for refluxing the fluid discharged from the storage tank to the storage tank via the ice making device.
The reflux path includes an ice particle separation mechanism that separates ice particles from the fluid discharged from the storage tank to extract salt water, and a pumping means that sends the extracted salt water to the ice making apparatus. It is a feature.

According to this configuration, a sherbet-like fluid having a high ice content can be produced by repeatedly refluxing the stored salt water in the storage tank using a 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 agitated by a stirrer to prevent the ice particles from binding to each other and to enter the recirculation path. The provided ice particle separation mechanism can separate ice particles from the sherbet-like fluid discharged from the storage tank and supply the extracted salt water to the ice making apparatus. As a result, the ice content of the sherbet-like fluid stored in this storage tank can be increased while stirring the sherbet-like fluid in one storage tank, so that the sherbet-like fluid can be contained without increasing the size of the equipment. A sherbet-like fluid with a high ice content can be produced.

The invention according to claim 2 is the ice making system according to claim 1.
The reflux pathway is
It is characterized by having an ice particle return mechanism for returning ice particles separated by the ice particle separation mechanism into the storage tank.

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

The invention according to claim 3 is the ice making system according to claim 2.
The ice particle separation mechanism is provided at or near the fluid discharge port of the storage tank, and has a separation filter that separates ice particles from the sherbet-like fluid.
The ice particle return mechanism is characterized by comprising a pressure applying means for applying a fluid pressure to the ice particles deposited on the separation filter in a direction opposite to the flow direction of the reflux path.

According to this configuration, the ice particles accumulated on the separation filter can be removed by the pressure applying means and returned to the storage tank, so that a sherbet-like fluid having a simple structure and a high ice content can be efficiently generated. Can be done.

The invention according to claim 4 is the ice making system according to any one of claims 1 to 3.
A circulation pipe that connects the outlet and the inlet formed in the storage tank without using the ice making device, and a pressure feed that pumps the fluid in the circulation pipe from the outlet to the inlet. It is characterized by having a circulation path having means and.

According to this configuration, when the ice content of the sherbet-like fluid in the storage tank becomes high, the sherbet-like fluid can be circulated by the circulation path as well as being stirred by the stirring device. When maintaining the fluidity of a sherbet-like fluid having a high ice content only with a stirrer, it is necessary to sufficiently increase the stirring speed in order to eliminate the non-stirred region, but this causes ice particles in the region close to the stirring portion. May melt. By circulating the sherbet-like fluid through the circulation path together with the stirring, it is possible to maintain the fluidity of the sherbet-like fluid while suppressing an increase in the stirring speed and preventing the melting of ice particles.

The invention according to claim 5 is the ice making system according to any one of claims 1 to 4.
The final ice content of the sherbet-like fluid in the storage tank is 70% or more.

According to this configuration, the fluid in the storage tank can be a sherbet-like fluid suitable for pipeline cleaning.

The invention according to claim 6 is the ice making system according to any one of claims 1 to 5.
The ice making device
A cylindrical cooling drum whose inner peripheral surface is cooled by a heat exchange medium,
An August cru, which is arranged inside the cooling drum and has a cylindrical outer peripheral surface having a spiral blade 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 and for injecting salt water between the inner peripheral surface of the cooling drum and the outer peripheral surface of the August cru.
A discharge port provided at the other end of the cooling drum and discharging a sherbet-like fluid containing ice particles conveyed by the August cru.
It is characterized by being equipped with.

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

The invention according to claim 7
An ice making method for producing a sherbet-like fluid containing ice particles by using the ice making system according to any one of claims 1 to 6.
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 by the stirring device, and
Including
By repeating the reflux step a plurality of times while performing the stirring step, the ice content of the sherbet-like fluid in the storage tank is increased to 70% or more.

According to this configuration, when the ice content of the sherbet-like fluid in the storage tank becomes high, the sherbet-like fluid in the storage tank is agitated by the stirring device to prevent the ice particles from binding to each other. The ice particle separation mechanism provided in the recirculation 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 apparatus. As a result, a sherbet-like fluid having an ice content of 70% or more can be generated while preventing problems due to clogging of ice particles and the like.

The invention according to claim 8 is a method for cleaning a pipeline using a sherbet-like fluid produced by the ice making system according to any one of claims 1 to 6.
A step of taking out a part of the fluid from the tank containing the sherbet-like fluid and measuring the ice content, and
Based on the measurement results, the ice content of the sherbet-like fluid is adjusted as necessary so that the ice content of the sherbet-like fluid in the tank is within a predetermined target ice content range. Process and
It is characterized by including a step of cleaning a 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 kept within the target ice content range, which is more suitable for cleaning. It can be a sherbet-like fluid.

According to the ice making system and the ice making method of the present invention, a sherbet-like fluid having a high ice content can be produced by repeatedly refluxing the stored salt water in the storage tank using a reflux path. Further, by separating ice particles from the sherbet-like fluid by an ice particle separation mechanism provided in the reflux path and extracting salt water, this storage tank is used while stirring the sherbet-like fluid in one storage tank. Since the ice content of the sherbet-like fluid stored in the container can be increased, a sherbet-like fluid having a high ice content can be produced without increasing the size of 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.

The block diagram of the ice making system according to the embodiment of this invention. A partial cross-sectional view schematically showing a part of an ice making device. Partial sectional view schematically showing another example of an ice making apparatus. Explanatory drawing which shows the ice particle separation mechanism and the ice particle return mechanism in an ice making system. Explanatory drawing which shows another example of an ice particle separation mechanism and an ice particle return mechanism in an ice making system. FIG. 5 is a cross-sectional view schematically showing another embodiment of a storage tank and a stirrer. Explanatory drawing of means for measuring the ice content of a sherbet-like fluid. FIG. 5 is a cross-sectional view schematically showing a pipeline cleaning system using a sherbet-like fluid.

It is a block diagram of the ice making system which is the embodiment of this invention of FIG. 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, a stirring device 35, and a third. The first recirculation pipe 41, the second recirculation pipe 42, and the circulation pipe 52 are provided. The first reflux pipe 41 and the second reflux pipe 42 are pipes connecting the ice making device 20 and the storage tank 30, respectively, and the storage tank 30, the first reflux pipe 41, the ice making device 20, and the second reflux pipe 42 are stored. It constitutes a reflux path 40 through which the salt water stored in the tank 30 returns. The reflux path 40 is provided with a separation filter (ice particle separation mechanism) 44, an ice particle return mechanism 46, and a pump (pumping means) 43.

As shown in FIGS. 1 and 2, the ice making device 20 includes a refrigerating circuit 21, a cooling drum 22, and an August cru 26 arranged inside the cooling drum 22.

The refrigeration circuit 21 includes a compressor that compresses the refrigerant, a condenser, an expansion valve that expands the refrigerant, an evaporator, and a refrigerant pipe 28 through which the refrigerant that circulates the refrigerant flows. The refrigerant circulates in the refrigerant pipe 28 forming a closed loop in the refrigeration circuit 21 and undergoes a thermal cycle 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 integrally formed with the inner cylinder 22A. A part of the refrigerant pipe 28 (hereinafter, referred to as a cooling pipe 24) constituting 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 having a high thermal conductivity, and the outer cylinder 22B is made of a material having a low thermal conductivity. An injection port 23a for injecting salt water is formed inside the inner cylinder 22A at one end of the cooling drum 22 (the lower end of the cooling drum 22 extending in the vertical direction in the illustrated example), and the other end (illustrated example). The discharge port 23b is formed at the upper end portion).

The August cru 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 August cru 26 is rotationally driven in the cooling drum 22 by a drive mechanism 27 provided on one end side, scrapes ice adhering to the inner peripheral surface 23c of the cooling drum 22, and conveys it to the discharge port 23b. In the present embodiment, the injection port 23a and the discharge port 23b of the cooling drum 22 are provided in the region where the rotary blade 26b of the August cru 26 is arranged.

In this ice making device 20, in the cooling drum 22, heat is exchanged between the salt water injected into the cooling drum 22 from the injection port 23a and the refrigerant flowing through the cooling pipe 24, so that the salt water is cooled and becomes ice-like. And adheres to the inner peripheral surface 23c of the cooling drum 22. The attached ice is scraped off by the rotary blade 26b of the August cru 26, becomes a sherbet-like fluid 12 containing ice particles 14, and is discharged from the discharge port 23b.

The particle size (major axis) of the ice particles 14 constituting the sherbet-like fluid 12 is 5 mm or less, and the average particle size is preferably 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. The ice making device 20 includes a cooling drum 62 in which the inner peripheral surface 63 is cooled by the refrigerant circulating in the refrigeration circuit, and a sealing member 61 for sealing one end (upper end in FIG. 3) of the cooling drum 62. A rotating shaft 65, which is pivotally supported by the member 61 and arranged on the central axis of the cooling drum 62, is provided.

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

The rotating shaft 65 penetrates the sealing member 61 and is rotatably supported by the sealing member 61 by a bearing member 61a fitted between the rotating shaft 65. The rotating shaft 65 is rotated about an axis by a geared motor (not shown) installed above the sealing member 61. The rotating shaft 65 in the cooling drum 62 includes a plurality of pipes 66 having injection holes 66a at the tip thereof, which rotate together with the rotating shaft 65 and inject salt water toward the inner peripheral surface 63 of the cooling drum 62, and the rotating shaft 65. A rotary blade 67 that rotates with the rotary blade 67 is attached. The plurality of pipes 66 are arranged on the outer peripheral surface of the rotating shaft 65 at substantially equal intervals, and extend radially 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 salt water is sprayed toward the upper portion 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 scrapes the sherbet-like ice formed on the inner peripheral surface 63 of the cooling drum 62, which is formed on the arm portion extending radially outward from the rotary shaft 65 and the tip of the arm portion. 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 extending in the rotation shaft 65 in the axial direction and communicating with each pipe 66 is formed in the upper portion of the rotation shaft 65. The top of the rotating shaft 12 is connected to the first recirculation pipe 41 by a joint member (not shown), and the salt water supplied from the first recirculation 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 injected into the cooling drum 22 from each pipe 66 rotating together with the rotating shaft 65 is cooled and ice is passed through the communication hole 67 of the rotating shaft 65 rotated by the geared motor. It becomes shaped and adheres to the inner peripheral surface 63 of the cooling drum 62. The attached ice is scraped off by the blade portion of the rotary blade 67, becomes a sherbet-like fluid 12 containing ice particles 14, is discharged from the lower surface side of the cooling drum 62, and is stored in the storage tank 30. Such an ice making device 20 can be manufactured by referring to, for example, the device described in JP-A-2017-72358. In such an ice making device 20, the ice content can be increased as compared with the auger type ice making device shown in FIG.

In the ice making apparatus 20 shown in FIGS. 2 and 3, the temperature of the inner peripheral surface of the cooling drum can be, for example, −30 ° C. to −60 ° C. Further, since the salt concentration of the ice particles 14 generated by the ice making device 20 is lower than that of the salt water around the ice particles 14, 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 a sherbet-like fluid 12 having an ice content of about 80% is produced by a method described later using salt water having a salinity of 5% by mass, the salt concentration in the salt water becomes 8 to 10% by mass, which is a part. The salt content of the above can be in a state of being contained in the ice particles 14.

The storage tank 30 stores salt water and the sherbet-like fluid 12 generated 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 the present 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. Further, the storage tank 30 has a salt inlet (not shown) at the top.

The stirring device 35 has a stirring blade 37 arranged in the storage tank 30, and the fluid in the storage tank 30 is stirred by driving the stirring blade 37 by the motor 36.

One end of the first reflux pipe 41 is connected to the fluid discharge port 31a of the storage tank 30, and the other end is connected to the injection port 23a of the cooling drum 22 of the ice making device 20. The first outlet 31a is formed at or near the bottom of the storage tank 30. The first reflux pipe 41 is provided with a pump 43 for flowing the fluid in the pipeline from the storage tank 30 side toward the ice making device 20 side, and a control valve 49 for opening and closing the flow path of the first reflux pipe 41. ing. The control valve 49 is arranged on the upstream side 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 that separates ice particles 14 from the sherbet-like fluid 12 to extract salt water. The separation filter 44 has a size smaller than the average particle size of the ice particles 14, and is formed in a tubular shape in the present embodiment. As shown in FIG. 4, by providing the separation filter 44 in almost the entire height direction of the hopper type discharge unit 33, it is possible to make the separation filter 44 less susceptible to the influence of stirring and to prevent the separation filter 44 from being clogged. The ice particles 14 can be properly separated.

The fluid (that is, salt water) from which the ice particles 14 have been separated by the separation filter 44 is sent to the ice making device 20 by the pump 43 arranged in the first reflux 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 in the vicinity of the downstream of the fluid discharge port 31a. The shape of the separation filter 44 is not limited to this, and may be, for example, a sheet having a required thickness. Further, instead of the separation filter 44, for example, an ice particle separation mechanism for separating ice particles 14 and salt water by centrifugation may be arranged in the reflux path 40.

An ice particle return mechanism 46 is provided in the vicinity of the separation filter 44. The ice particle return mechanism 46 returns the ice particles 14 separated by the separation filter 44 into the storage tank 30, and in the present embodiment, the branch pipe 47 branched from the first recirculation pipe 41 and the separation pipe 47. A pump (pressure applying means) 48 arranged in the above and a fluid supply control valve 45 are provided.

The upstream end of the branch pipe 47 is connected to the first reflux pipe 41 on the downstream side of the ice particle separation mechanism 44, and the downstream end of the other end is connected to the reflux path 40 near the ice particle separation mechanism 44. Will be done. In the present 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, when the flow path of the first recirculation pipe 41 is closed by the control valve 49, the opening and closing control of the valves 45 and 49 is performed so as to open the fluid supply control valve 45. The pump 48 pumps the fluid flowing through the branch pipe 47 from the upstream end side to the downstream end side with the fluid supply valve 45 open.

In the ice particle return mechanism 46 described above, the control valve 49 is closed, the fluid supply control valve 45 is open, and the pump 48 is driven to allow the salt water discharged from the fluid discharge port 31a to pass through the branch pipe 47. And jets toward the ice particles 14 deposited on the separation filter 44. As a result, the ice particles 14 deposited on the separation filter 44 are given a fluid pressure in the direction opposite to the flow direction of the reflux path 40, and the ice particles 14 removed from the separation filter 44 are returned to the storage tank 30. The ice particle return mechanism 46 separates the downstream end of the branch pipe 47 so as to reversely inject salt water from the downstream side (ice making device 20 side) to the upstream side (storage tank 30 side) of the separation filter 44. It may be arranged on the downstream side of 44.

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

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

The ice particle return mechanism 46 includes a pipe 72 that connects the downstream end of the separation filter 44 and the storage tank 30, and a pump 73 provided in the pipe 72. One end of the pipe 72 is connected to a through hole 38 formed at the bottom of the storage tank 30. In the 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 reverse-injected into the separation filter 44 to deposit on the separation filter 44. The ice particles 14 can be returned to the storage tank 30.

One end of the second reflux pipe 42 is connected to the discharge port 23b of the cooling drum 22, and the other end is connected to the fluid storage port 31b of the storage tank 30. The fluid storage port 31b is provided above the storage tank 30. The sherbet-like fluid generated by the ice making device 20 is stored in the storage tank 30 by the second reflux pipe 42. Although not shown, the second reflux pipe 42 may be provided with a pumping means such as a pump for pumping 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 using the ice making device 20, and a pump (pumping means) 53 is arranged in the flow path thereof. .. The circulation pipe 52 and the pump 53 form a circulation path 50 for circulating and moving the sherbet-like fluid 12 in the storage tank 30. The circulation path 50 may be configured to be provided with a screw pump as a pumping means instead of the pump 53.

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

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

First, water is stored in the storage tank 30, salt is charged from the salt inlet, and the stirring device 35 is driven to stir to generate salt water (salt water generation step). The proportion of salt in the 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 open. As a result, salt water having a uniform salt concentration can be produced at an early stage. In the salt water generation step, the reflux path 40 is in a reflux stopped 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 step, the flow path of the reflux path 40 is put into a flow state, and a pump 43 is driven to supply a part of the salt water in the storage tank 30 to the ice making device 20 to generate a sherbet-like fluid 12. , The stirring step of driving the stirring device 35 to stir the fluid in the storage tank 30 is performed at the same time.

In the reflux step, the salt water supplied to the ice making device 20 is cooled as it passes 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 August cru 26. The sherbet-like fluid 12 containing the ice particles 14 is discharged from the discharge port 23b of the cooling drum 22, and is stored in the storage tank 30 through the second reflux pipe 42. The ice-making rate of the sherbet-like fluid 12 generated from the salt water by the ice-making device 20 (that is, the ice-making rate when the salt water containing no ice particles 14 passes through the ice-making device 20 once) is, for example, about 30 to. It is 60%, preferably about 50-60%.

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

In the reflux step, 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 operating the ice particle return mechanism 46 and causing the separation filter 44 to reversely inject salt water under the pressure of the pump 48 via the branch pipe 47. be able to. By this reverse injection, the ice particles 14 adhering to the separation filter 44 are returned to the storage tank 30. The timing at which the ice particle return mechanism 46 is operated can be appropriately set. 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. Further, 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 a set value or more. When operating the ice particle return mechanism 46, the reflux through the reflux path 40 can be suspended.

In the ice making step, the circulation path 50 may circulate and move the fluid in the storage tank 30 continuously from the salt water generation step, but the pump 53 may be stopped after the salt water generation step to stop the distribution. .. In such a case, in the initial stage of the ice making process in which the ice content in the storage tank 30 is low, the distribution of the circulation path 50 is stopped, and the ice content in the storage tank 30 becomes a predetermined value or more (for example, 40% or more). At that time, the pump 53 is driven to bring it into a distribution state, and the sherbet-like fluid 12 is circulated and moved while performing the stirring step.

As described above, in the ice making step, the ice content is high in the storage tank 30 by repeating the recirculation step while simultaneously performing the recirculation step, the stirring step and the circulation step of moving the sherbet-like fluid 12 by the circulation path 50. A sherbet-like fluid 12 is produced, specifically, a sherbet-like fluid 12 having an ice content of 70% or more, preferably an ice content of 75 to 90%, more preferably 80 to 85%.

The particle size (major axis) of the ice particles constituting the sherbet-like fluid 12 is 5 mm or less, and the average particle size is preferably 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 step is completed, the flow state of the sherbet-like fluid 12 is maintained by stirring by the stirring device 35 and circulation by the circulation path 50.

According to the ice making system 10 described above, the sherbet-like fluid 12 having a high ice content can be produced by repeatedly refluxing the stored salt water 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 flow in the storage tank 30 is performed by circulating the sherbet-like fluid 12 through the circulation path 50 together with stirring by the stirring device 35. It is possible to prevent the ice particles 14 of the body 12 from binding to each other.

In general, when maintaining the fluidity of the sherbet-like fluid 12 having a high ice content only with the stirring device 35, it is necessary to sufficiently increase the stirring speed, and 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 together with stirring, the fluidity of the sherbet-like fluid 12 can be improved while suppressing an increase in the stirring speed and preventing the ice particles 14 from melting. Can be maintained.

Further, 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 by the separation filter 44 provided in the reflux path 40 is supplied to the ice making device 20. Therefore, it is possible to increase the ice content of the sherbet-like fluid 12 stored in the storage tank 30 while stirring the sherbet-like fluid 12 in one storage tank 30. As a result, the sherbet-like fluid 12 having a high ice content can be produced without increasing the size of the equipment.

Further, the ice particle return mechanism 46 can remove the ice particles 14 deposited on the separation filter 44 by using the fluid pressure and return them to the storage tank 30, so that the sherbet has a simple structure and an efficient high ice content. The state fluid 12 can be produced.

In the salt water generation step, the salt water stored in the storage tank 30 can have a temperature higher than 0 ° C., for example, room temperature. After the salt water generation step, by continuing the ice making step using the reflux path 40, 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 becomes a supercooled state in which the temperature becomes lower than 0 ° C. (for example, −5 ° C., etc.). As described above, when the liquid in the storage tank 30 is in the supercooled state, the sherbet flow state 12 in the storage tank 30 can maintain the ice particles 14 without melting.

The sherbet-like fluid 12 generated by using the ice making system 10 is 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, if necessary. It is transferred to the tank 58 and transported to the cleaning site by a construction vehicle equipped with the utilization tank 58. The utilization tank 58 is provided with a stirring device 58a, and constantly agitates the sherbet-like fluid 12 in the utilization tank 58. Further, 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 the construction vehicle and transported to the pipeline cleaning site. It can be configured. Further, the construction vehicle equipped with the ice making system 10 can be configured to be able to transport the entire ice making system 10 to the pipeline cleaning site, and in such a case, the structure can be such that the utilization tank 58 is not provided. The sherbet-like fluid 12 having an ice content of 70% or more is preferably always stirred until the washing operation is performed, and the stirring device 35 does not stop stirring for at least 15 minutes or more. It is controlled so as not to rest for 5 minutes or more, more preferably 1 minute or more.

FIG. 6 is a diagram showing another embodiment of the storage tank 30 and the agitator 35 used in the ice making system 10. 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 entire storage tank 30 is formed in a substantially cylindrical shape, and a fluid storage port 31b, an inflow port 32b, and a salt inlet 34 are provided at the upper part of the storage tank 30 in the installed state, and the fluid at the bottom. A discharge port 31a and an outlet 32a are provided. In FIG. 7, the description of the fluid discharge port 31a is omitted.

A hopper 32 is connected to the outflow port 32a, a circulation pipe 52 is connected to the downstream end of the hopper 32, and a screw pump 54 as a pumping means is provided inside the circulation pipe 52. When the drive device 56 connected to the screw 54 is turned on, the screw pump 54 rotates and pumps the fluid flowing into the hopper 32 to the inflow port 32b via the circulation pipe 52.

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

The representative speed of stirring of the stirring device 35 used in the storage tank 30 (the speed of the portion where the stirring speed is the fastest, that is, the outermost speed in the radial direction of the stirring blade) is about 0.1 to 0.2 m / s. Is preferable.

Further, the pipe 50A on the downstream side of the screw pump 54 is provided with an ice content measuring means 74 for measuring the ice content of the sherbet-like fluid 12. As shown in FIG. 7, the ice content measuring means 74 of the present embodiment is provided at the bypass pipe 76 connected to the pipe 50A and the upstream end and the downstream end of the bypass pipe 76 to open and close the pipeline. It includes valves 75B and 75C and a piston-shaped movable member 77 that changes the volume of the bypass pipe 76. In FIG. 7, only the sherbet-like fluid 12 in the region 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 cylindrical filter portion 77a that can slide on the inner peripheral surface of the bypass pipe 76, and a rod-shaped portion 77b for moving the filter portion 77a. The filter unit 77a is configured to allow passage of only salt water by setting the mesh size to be smaller than the average particle size of the ice particles 14.

In the ice content measuring means 74, as shown in FIG. 7A, the 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. Close. Next, as shown in FIG. 7B, by moving the movable member 77, one region partitioned by the filter portion 77a is filled with only the ice particles 14, and salt water is discharged to the other region. By measuring the amount of movement of the movable member 77 at this time, the ice content is indirectly measured. The relationship between the amount of movement of the movable member 77 in the bypass pipe 76 and the ice content can be set from the results of experiments conducted in advance. Further, by making the bypass pipe 76 a transparent pipe and providing a visible scale, it is possible to make it easier to visually recognize the amount of movement of the filter 77a that has moved in the pipe.

As an example, when the target ice content (predetermined target ice content) of the sherbet-like fluid is set to 80 to 85%, and the measurement result shows that the ice content is lower than the target value, the ice making device 20 The ice content can be further increased. When the measured ice content is higher than the target value, salt water can be supplied into the storage tank 30 from the salt water pipe 78 connected to the storage tank 30 to reduce the ice content. Instead of or at the same time, the ice content may be lowered 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 pipeline cleaning system 80. The pipeline cleaning system 80 includes a water supply main 82, which is an example of a pipeline to be cleaned, a plurality of branch pipes 84, 85 connecting the water supply main 82 and the outside, and an upstream section of the water supply main 82 to be cleaned. Water control valves 86a and 86b that close the open ends on the side and downstream sides, a fluid injection device 88 that pressurizes and injects the fluid 12 into the water supply main 82, and a recovery tank 89 that collects the fluid 12. And.

The water supply main 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. At the time of cleaning, the flow of clean water 98 of the section 90 to be cleaned can be stopped by closing the water control valves 86a and 86b located at both ends of the section 90 to be cleaned of the water supply main 82.

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

Of the branch pipes 84 and 85, the branch pipe 84 located 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 located on the other end side is , Used as a discharge pipe for discharging the sherbet-like fluid 12. In the example shown in FIG. 8, the branch pipes 84, 85 project from the ground into the recesses 94, 95 dug to a predetermined depth, and are interposed through the water stop valves 91, 92 attached to the branch pipes 84, 85. , It is connected to the connection pipe 96 which is an injection pipe and the connection pipe 97 which is a discharge pipe.

The fluid injection device 88 includes a storage tank 30 or a utilization tank 58 accommodating the sherbet-like fluid 12, and a pumping means (for example, a screw pump or the like) for pumping the fluid 12 in the tank into the injection communication pipe. Be prepared. In the present embodiment, the ice making system 10 is mounted on the 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 is composed of a tank system. The fluid injection device 88 is arranged 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 20 via the connecting pipe 96 and the branch pipe 84. In the present embodiment, as shown in FIG. 6, the flow path is switched by the three-way valve 55A provided in the circulation pipe 52, and the sherbet-like fluid 12 pumped by the screw pump 54 is connected via the three-way valve 55A. It can be injected into the connecting pipe 96.

The recovery tank 89 is a tank for recovering the sherbet-like fluid 12 after cleaning, and is installed at the downstream end of the connection pipe 97 which is a discharge pipe.

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

First, as shown in FIGS. 6 and 7, the ice content of the sherbet-like fluid 12 in the storage tank 30 is measured by the ice content measuring means 74 provided with the fluid injection device 88 arranged on the ground. .. If it is determined from the measurement results that the ice content exceeds the target ice content range, 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 contained in the storage tank 30 from the salt water pipe 78. The sherbet-like fluid 12 is adjusted within the range of the target ice content by supplying water to reduce the 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. Further, 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 out to the downstream side 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 pipeline cross section in a small part of the section 90 to be cleaned. In the present embodiment, the sherbet-like fluid 12 is filled over the entire area of the section 90 to be cleaned, and is pressurized so as to move in the section 90 to be cleaned 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. Sediments adhere to the inner wall of the water supply main 82 that has been used for many years, and the sherbet-like fluid 12 moves to scrape off the adhered deposits and clean the inside of the pipeline. Will 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 a long-distance pipeline while scraping off the deposits. In the water supply main 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 deposits and the like are discharged into the recovery tank 89 via the branch pipe 85 and the connecting pipe 97. Although not shown, a water quality monitoring device is connected to the discharge pipe, and the turbidity, temperature, pressure in the pipeline, etc. of the sherbet-like fluid 12 discharged by the water quality monitoring device are monitored.

When the injection of the sherbet-like fluid 12 in the amount required for cleaning is completed, the water stop valve 91 is closed. Next, by opening the water control valve 86a on the upstream side and flowing the clean water 98 to the section 90 to be cleaned, the sherbet-like fluid 12 in the water supply main 82 is flushed and discharged from the branch pipe 85 to the outside. .. Such flushing of the section 90 to be washed 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 attached deposits are removed by the sherbet-like fluid 12 and discharged together with the sherbet-like fluid 12 so that the pipeline can be appropriately cleaned. By using the sherbet-like fluid 12 having a high ice content, the force for scraping off the deposits is increased to enhance the detergency, and the removed deposits are appropriately maintained by the solid ice particles 14 without being retained in the pipeline. Can be discharged to.

Further, the cleaning effect can be enhanced by measuring the ice content before injecting the sherbet-like fluid 12 into the water supply main 82 and adjusting the ice content so as to reach the target ice content.

For example, if the place where the sherbet-like fluid 12 is generated is far 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, so that the ice content may decrease during ice making. , A 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 when the ice content is still higher than the target value, salt water is supplied to keep the ice content within the target range, so that the sherbet-like fluid 12 Liquidity can be ensured.

The pipeline to be cleaned is not limited to the water supply pipe, but may be a sewer pipe, an industrial / farm pipe, or the like. When cleaning the sewer pipe, for example, the section to be cleaned can be set to about 15 to 300 m with respect to the sewer pipe having an inner diameter of about 150 to 600 mm, and the ice content of the sherbet-like fluid 12 is set to 70% or more. As a result, it is possible to appropriately transport and discharge the removed sediment while maintaining the scraping performance of ice particles in the section to be cleaned.

The present invention is not limited to the above-described embodiments and modifications, and various modifications can be made without departing from the spirit of the invention.

10 Ice making system 20 Ice making device 21 Refrigeration circuit 22 Cooling drum 24 Cooling pipe 26 August cru 28 Refrigerant pipe 30 Storage tank 35 Stirrer 40 Reflux path 41 1st reflux pipe 42 2nd reflux pipe 44 Ice particle separation mechanism 46 Ice particle return mechanism 48 Pump (pressure applying means)
50 Circulation route 52 Circulation piping 58 Utilization tank 80 Pipeline cleaning system

Claims (8)

An ice maker that cools salt water to produce sherbet-like fluid containing ice particles,
A storage tank for storing the sherbet-like fluid generated by the ice making device, and
A stirring device that stirs the sherbet-like fluid in the storage tank,
In an ice making system provided with a reflux path for refluxing the fluid discharged from the storage tank to the storage tank via the ice making device.
The reflux path includes an ice particle separation mechanism that separates ice particles from the fluid discharged from the storage tank to extract salt water, and a pumping means that sends the extracted salt water to the ice making apparatus. The featured ice making system. The reflux pathway is
The ice making system according to claim 1, further comprising an ice particle return mechanism for returning ice particles separated by the ice particle separation mechanism into the storage tank. The ice particle separation mechanism is provided at or near the fluid discharge port of the storage tank, and has a separation filter that separates ice particles from the sherbet-like fluid.
2. The ice particle return mechanism according to claim 2, further comprising a pressure applying means for applying a fluid pressure to the ice particles deposited on the separation filter in a direction opposite to the flow direction of the reflux path. Ice making system. A circulation pipe that connects the outlet and the inlet formed in the storage tank without using the ice making device, and a pressure feed that pumps the fluid in the circulation pipe from the outlet to the inlet. The ice making system according to any one of claims 1 to 3, further comprising a circulation path having the means. The ice making system according to any one of claims 1 to 4, wherein the final ice content of the sherbet-like fluid in the storage tank is 70% or more. The ice making device
A cylindrical cooling drum whose inner peripheral surface is cooled by a heat exchange medium,
An August cru, which is arranged inside the cooling drum and has a cylindrical outer peripheral surface having a spiral blade 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 and for injecting salt water between the inner peripheral surface of the cooling drum and the outer peripheral surface of the August cru.
A discharge port provided at the other end of the cooling drum and discharging a sherbet-like fluid containing ice particles conveyed by the August cru.
The ice making system according to any one of claims 1 to 5, wherein the ice making system is provided. An ice making method for producing a sherbet-like fluid containing ice particles by using the ice making system according to any one of claims 1 to 6.
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 by the stirring device, and
Including
An ice making method, characterized in that the ice content of the sherbet-like fluid in the storage tank is increased to 70% or more by repeating the reflux step a plurality of times while performing the stirring step. A method for cleaning a pipeline using a sherbet-like fluid produced by the ice making system according to any one of claims 1 to 6.
A step of taking out a part of the fluid from the tank containing the sherbet-like fluid and measuring the ice content, and
Based on the measurement results, the ice content of the sherbet-like fluid is adjusted as necessary so that the ice content of the sherbet-like fluid in the tank is within a predetermined target ice content range. Process and
A method for cleaning a pipeline, which comprises a step of cleaning the pipeline using a sherbet-like fluid having a target ice content.

Images