JP2017217586A - Mixing system, washing equipment of mixing tank, and manufacturing method of slurry - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mixing system capable of suppressing clogging of a nozzle without changing a concentration of slurry.SOLUTION: A mixing system 10 including a mixing tank 20 and an agitator 30, for manufacturing slurry, includes a nozzle 51 provided in the mixing tank 20 so as to jet out water toward the inner surface of the mixing tank 20, a water supply part 52 for supplying high pressure water to the nozzle 51, and a gas supply part 53 for supplying gas to the nozzle 51 so as to prevent clogging of the nozzle 51.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a mixing system for producing a slurry by stirring water and cement.

  Conventionally, a mixing system for kneading water and a slurry material such as cement is known. In this type of mixing system, a solidified product obtained by solidifying the slurry adheres to the inner surface of the mixing tank. For this reason, it is necessary to remove the solidified product, and much effort is required for the work of removing the solidified product.

  Patent Document 1 describes a cleaning device for a kneading container such as cement milk. In this cleaning apparatus, a base of a swinging rod is pivotally mounted on the upper side of the drive shaft so as to swing up and down, a float is provided on the swinging rod, and a nozzle is provided on the upper surface of the swinging rod. Is. The hose connected to the nozzle is connected to a drive shaft water channel provided in a hollow portion of the drive shaft. Further, the drive shaft water channel is connected to a water supply pipe led out from a pressure water source via a rotating part water supply mechanism. The water jetted from the nozzle collides from the center of the cover plate to the upper part of the container side wall as the float moves up and down. Further, in this cleaning device, a small amount of water is discharged so that the nozzle hole is not clogged even if the sprayed droplets of cement milk are applied to the nozzle hole.

JP-A-4-161303

  By the way, the prior art employs a complicated structure in which the rocking rod is floated by a float. Further, in a construction site where a mixing system is used, there is a case where the supply of slurry from the mixing tank to the slurry supply place is temporarily stopped and waited. In such a case, even if the amount is small, when water is discharged from the nozzle, the concentration of the slurry changes. Therefore, water may not be discharged from the nozzle, and the nozzle may be clogged.

  This invention is made | formed in view of such a situation, and it aims at providing the mixing system which can suppress clogging of a nozzle, without changing the density | concentration of a slurry.

  In order to solve the above-described problems, the first invention includes a mixing tank for mixing liquids and a stirring device for stirring the liquid in the mixing tank, and the water and cement in the mixing tank are stirred by the stirring device. A mixing system for producing slurry by performing a nozzle, a nozzle provided in the mixing tank so as to inject water toward the inner surface of the mixing tank, a water supply unit for supplying high-pressure water to the nozzle, and a nozzle A gas supply unit for supplying gas to the nozzle to prevent clogging

  According to a second aspect, in the first aspect, in the mixing tank, gas is supplied to the nozzle after the period when the high-pressure water sprayed from the nozzle is accumulated as a slurry material until the slurry is discharged. A control unit for controlling the gas supply unit is further provided.

  According to a third aspect of the present invention, in the first or second aspect, the mixing tank has an upper surface portion that closes the upper side formed in a dome shape, and the mixing tank is provided with a plurality of nozzles, and the plurality of nozzles are formed on the upper surface portion. The nozzle arrange | positioned in the position lower than a lower end and the nozzle arrange | positioned in the position higher than the lower end of an upper surface part are included.

  According to a fourth invention, in the first or second invention, the mixing tank is provided with a plurality of nozzles, and the plurality of nozzles are arranged at a lower portion of the indoor space of the mixing tank, and at an upper portion of the indoor space. Arranged nozzles.

  According to a fifth invention, in any one of the first to fourth inventions, a second water supply unit that supplies water as a slurry material to the mixing tank through a pipe that opens to the mixing tank is further provided. .

  A sixth invention is a cleaning device for a mixing tank that cleans the inside of a mixing tank in which slurry is produced by stirring water and cement, and jets water toward the inner surface of the mixing tank. High pressure water sprayed from the nozzle, provided with a nozzle provided in the mixing tank, a water supply part for supplying high pressure water to the nozzle, and a gas supply part for supplying gas to the nozzle to prevent clogging of the nozzle To clean the inside of the mixing tank.

  A seventh invention is a slurry production method for producing a slurry by stirring water and cement, and high pressure water is used as a slurry material from a nozzle provided in the mixing tank toward the inner surface of the mixing tank. A water storage step for injecting and storing the injected water in the mixing tank; a material supply step for supplying a slurry material other than water to the mixing tank; and a liquid in the mixing tank after the water storage step and the material supply step. A stirring step of stirring the gas, and supplying gas to the nozzle in the stirring step

  In 1st invention, in order to prevent clogging of a nozzle, the gas supply part which supplies gas to a nozzle is provided. Therefore, by supplying gas to the nozzle when the slurry is accumulated in the mixing tank, the slurry can be prevented from flowing into (intruding into) the nozzle without changing the concentration of the slurry. The gas supply unit that does not change the concentration of the slurry can be used even in a state where the supply of the slurry from the mixing tank to the slurry supply place is temporarily stopped and waiting, and clogging of the nozzle can be suppressed.

  In the second invention, the high-pressure water sprayed from the nozzle is stored in the mixing tank as a slurry material. That is, the inside of the mixing tank is washed during the slurry production process during a period in which water is accumulated in the mixing tank. Then, gas is supplied to the nozzle until the slurry is discharged after the period of storing water in the mixing tank is completed. Therefore, the inside of the mixing tank can be cleaned using the slurry production process while suppressing the slurry from flowing into the nozzle.

  In 3rd invention, the nozzle is arrange | positioned in the position higher than the lower end of an upper surface part. Here, conventionally, the upper surface of the mixing tank has a flat plate shape, and the space on the liquid surface has been narrowed. A large amount of solidified solidified slurry adheres to the vicinity of the outer periphery of the inner surface of the upper surface portion. In the third aspect of the invention, the upper surface portion is formed in a dome shape so that the space on the liquid surface is widened, and the nozzle is present on the liquid surface, so that the vicinity of the outer periphery on the inner surface of the upper surface portion ) Is easy to clean. In addition, since the nozzle is arranged at a position lower than the lower end of the upper surface portion, the inner surface of the mixing tank can be extensively cleaned in the height direction. According to the third aspect of the invention, the inner surface of the mixing tank can be cleaned over a wide range in the height direction, and a region where a large amount of fixed matter is attached can be reliably cleaned.

  In the fourth aspect of the invention, the nozzles are present in the upper and lower portions of the indoor space of the mixing tank. Therefore, the inner surface of the mixing tank can be cleaned over a wide range in the height direction. The “upper part” is an upper part from the middle in the height direction, and the “lower part” is a lower part from the middle in the height direction.

  In 5th invention, in addition to the water sprayed from a nozzle, water is supplied as a material of a slurry from the piping opened to a mixing tank. Therefore, the amount of water necessary for the production of the slurry can be supplied in a short time.

  In the sixth aspect, similarly to the first aspect, the slurry can be prevented from flowing into the nozzle without changing the concentration of the slurry, and clogging of the nozzle can be suppressed.

  In 7th invention, gas is supplied to a nozzle in a stirring step. Therefore, similarly to the first invention, the slurry can be prevented from flowing into the nozzle without changing the slurry concentration, and the nozzle can be prevented from being clogged.

Schematic configuration diagram of a mixing system according to an embodiment Block diagram of control system of mixing system Flow chart of system control processing executed by control unit Schematic diagram for explaining system control processing

  Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. The following embodiment is an example of the present invention, and is not intended to limit the scope of the present invention, its application, or its use.

[1. About the configuration of the mixing system]
The mixing system 10 is, for example, a mixing plant that produces cement milk (slurry). As shown in FIG. 1, the mixing system 10 includes a mixing tank 20, a stirring device 30, and a storage tank (agitator) 40. In FIG. 1, the inside of the mixing tank 20 is shown. The mixing tank 20 and the stirring device 30 constitute a mixer. In this embodiment, water, cement, bentonite and an admixture are used as the slurry material. However, the slurry material may be only water and cement, or other materials may be added to the water and cement. Also good.

  The mixing tank 20 includes a cylindrical main body portion 21, an upper surface portion 22 that closes the upper side of the main body portion 21, and a bottom surface portion 23 that closes the lower side of the main body portion 21. The outer periphery of the upper surface part 22 is connected to the outer periphery of the upper end of the main body part 21. The upper surface portion 22 is formed in a dome shape that swells upward. In the upper surface portion 22, an insertion hole 24 through which the shaft 31 of the stirring device 30 is inserted is formed in the center portion, and a cement charging port 25 is formed outside the insertion hole 24. A hopper 28 (see FIG. 2) is connected to the cement insertion port 25. In addition, a water supply pipe 82 provided with a water supply pump 81 is opened on the upper surface portion 22. Water from the fresh water tank 80 is supplied to the mixing tank 20 by a water supply pump 81 through a water supply pipe 82. Further, the upper end of the discharge pipe 26 provided with the discharge valve 29 is connected to the bottom surface portion 23. The lower end of the discharge pipe 26 opens to the upper space of the storage tank 40. Further, the bottom surface portion 23 is inclined so that the cement milk flows toward the discharge pipe 26. Although not shown, the mixing tank 20 is connected to a bentonite supply unit that supplies bentonite to the mixing tank 20 and an admixture supply unit that supplies the admixture to the mixing tank 20.

  The mixing tank 20 is in a state where the amount of cement milk is maximized (a state where the cement milk material has been charged), and the liquid level is below the upper end of the main body 21 (substantially lower end of the upper surface portion 22). As used. The main body 21 has a constant diameter over the height direction. In the mixing tank 20, the height at which the diameter starts to decrease is the boundary between the main body portion 21 and the upper surface portion 22.

  The stirring device 30 includes a cylindrical shaft 31, a plurality of blades 32 attached to the lower end portion of the shaft 31, and a drive device 33 that rotates the shaft 31. The shaft 31 extends in the vertical direction and is disposed at the center of the mixing tank 20. The shaft 31 protrudes upward from the upper surface portion 22 of the mixing tank 20 through the insertion hole 24 from the vicinity of the bottom surface portion 23 of the mixing tank 20. A plurality of nozzles 51 a, 51 b, 51 c are attached to the shaft 31. In addition, an in-shaft channel 31 a is formed along the axis inside the shaft 31. The plurality of blades 32 extend radially outward from the lower end of the shaft 31.

  The driving device 33 is disposed in a storage box 15 formed on the upper side of the mixing tank 20. The driving device 33 includes a motor 33 a and the like, and is configured to transmit the driving force of the motor 33 a to the upper portion of the shaft 31.

  The storage tank 40 is provided with a stirring device 41 separately from the mixing tank 20. The stirring device 41 includes a motor provided on the top plate of the storage tank 40, a shaft rotated by the motor, and a plurality of blades provided at the lower portion of the shaft.

[2. About cleaning equipment]
As shown in FIG. 1, the mixing system 10 further includes a cleaning device 50 for a mixing tank. The cleaning device 50 includes a plurality of nozzles 51 a, 51 b, 51 c that inject water, a first pump 52 that supplies high-pressure water to the nozzles 51 a to 51 c, and a first unit that supplies air (gas) to the nozzles 51 a to 51 c. 2, a connection channel 54 that connects the first pump 52 and the second pump 53 to the nozzles 51 a to 51 c, respectively, and a controller 55 (see FIG. 2) that controls the cleaning operation and the like . The control unit 55 controls not only the cleaning device 50 but the entire mixing system 10.

  The connection flow path 54 includes an in-shaft flow path 31a and a connection pipe 60 that forms an out-shaft flow path. The connection pipe 60 is connected to the in-shaft channel 31 a via a swivel joint 56 attached to the upper part of the shaft 31. The connection pipe 60 is a high-pressure in-line check valve 57 connected in the middle, and branches into two hands, a first branch pipe 61 and a second branch pipe 62. The first branch pipe 61 is connected to the discharge port of the first pump 52, and the second branch pipe 62 is connected to the discharge port of the second pump 53. The first branch pipe 61 is provided with a first electromagnetic valve 71, and the second branch pipe 62 is provided with a second electromagnetic valve 72. The suction port of the first pump 52 is connected to a water suction pipe 73 for sucking water from the fresh water tank 70. The fresh water tank 70 and the fresh water tank 80 may be combined into one.

  The plurality of nozzles 51 a to 51 c are directly attached to the shaft 31. In the present embodiment, the first nozzle 51a, the second nozzle 51b, and the third nozzle 51c are attached in order from the upper side. The number of nozzles 51a to 51c is not limited to three, and may be one, or two or four or more. Moreover, in this Embodiment, the nozzles 51a-51c which inject water into a fan shape are used, and each nozzle 51a-51c is provided so that a fan-shaped water injection surface may become vertical (refer FIG. 4). However, other types of nozzles such as nozzles that spray water in a conical shape may be used.

  The plurality of nozzles 51a to 51c are arranged at substantially equal intervals in the height direction. The plurality of nozzles 51 a to 51 c are respectively provided on the upper portion, the center portion, and the lower portion of the shaft 31 in the mixing tank 20. The inlets of the nozzles 51a to 51c are connected to the in-shaft channel 31a. The in-shaft channel 31a extends at least from the vicinity of the upper end of the shaft 31 downward to the height of the third nozzle 51c.

  The first nozzle 51a is positioned above the height of the upper end of the main body portion 21 of the mixing tank 20 so that the first nozzle 51a is not immersed in the cement milk even in the charged state (that is, positioned on the liquid surface). ing. The second nozzle 51 b and the third nozzle 51 c are located below the height of the upper end of the main body 21. In addition, the first nozzle 51a and the second nozzle 51b have tip portions that are substantially horizontal so as to eject water in a substantially horizontal direction. The tip of the third nozzle 51c faces obliquely downward so as to inject water obliquely downward. In the third nozzle 51c, the position of the shaft 31 in the circumferential direction is shifted from any blade 32 so that water hits the bottom surface portion 23. In addition, the direction of each nozzle 51a-51c is not limited to this Embodiment. For example, the tip portions of all the nozzles 51a to 51c may be substantially horizontal, the tip portion of the first nozzle 51a faces obliquely upward (for example, 45 degrees), and the tip portions of the other nozzles 51b and 51c You may face substantially horizontal. Moreover, you may enable it to adjust direction for each nozzle 51a-51c manually.

  The control unit 55 controls a main operation of producing cement milk in the mixing tank 20 and discharging it to the storage tank 40 and a cleaning operation of cleaning the inner surface of the mixing tank 20 by the cleaning device 50. Specifically, the control unit 55 is configured by a control board. The control board is provided with a power switch of the mixing system 10 and a weight input unit (not shown) that can input a set weight of each material of cement milk. As shown in FIG. 2, the control unit 55 includes a mixing system such as a drive device 33, a hopper 28, a discharge valve 29, a first pump 52, a second pump 53, a first electromagnetic valve 71, and a second electromagnetic valve 72. Connected to 10 components and controls each of these components.

  The control unit 55 is connected to a load sensor 58 (load cell) that detects the load of the mixing tank 20. The load sensor 58 detects the amount of change in the load of the mixing tank 20 and is used for weighing each material of cement milk. Note that the weighing of each material by the load sensor 58 is not limited to the method using the load sensor 58, and for example, a flow meter can be used for weighing water.

  In addition, the washing | cleaning apparatus 50 can be retrofitted not only to the new mixing system 10 but to the existing mixing system. In that case, the shaft originally used for the mixing tank 20 of the existing mixing system is replaced with the shaft 31 with the nozzles 51 a to 51 c, and the connection pipe 60 is connected to the in-shaft channel 31 a of the shaft 31. By performing the work, it can be attached to an existing mixing system.

[3. Control action by control unit]
With reference to FIG.3 and FIG.4, the system control process which the control part 55 performs including the manufacturing method of cement milk is demonstrated. The system control process is performed by the processor reading, executing, and interpreting the program stored in the memory. However, some or all of the functions of the system control process may be realized by a dedicated LSI such as an FPGA. In addition, in FIG.4 (c) and (d), description of the water supply pump 81, the water supply pipe | tube 82, and the fresh water tank 80 is abbreviate | omitted.

  In the initial state in which the power switch is OFF, the mixing tank 20 is empty as shown in FIG. Further, the hopper 28, the discharge valve 29, the first electromagnetic valve 71, and the second electromagnetic valve 72 are all closed. When the operator switches the power switch to ON in the initial state, the control unit 55 activates the motor 33a of the drive device 33 in step ST1. Subsequently, in step ST2, the control unit 55 activates the water supply pump 81 and the first pump 52 to start water supply. Specifically, the control unit 55 activates the water supply pump 81, switches the first electromagnetic valve 71 to the open state as a cleaning operation, and activates the first pump 52 immediately thereafter. Step ST1 and step ST2 are performed almost simultaneously.

  Thus, the water supply pump 81 sucks water from the fresh water tank 80 and discharges the water, whereby water is supplied to the mixing tank 20 via the water supply pipe 82. The first pump 52 sucks water from the fresh water tank 70 and discharges high-pressure water. As shown in FIG. 4B, the discharged high-pressure water sequentially flows through the first branch pipe 61, the downstream portion of the branch portion of the connection pipe 60, and the in-shaft flow path 31a, and the nozzles 51a to 51c. Distributed to. Each nozzle 51 a to 51 c sprays high-pressure water while rotating together with the shaft 31. In the present embodiment, a water supply unit that supplies high-pressure water to the nozzles 51a to 51c by the first pump 52, the first branch pipe 61, the downstream portion of the branching portion of the connection pipe 60, and the in-shaft channel 31a. Is configured. Further, the water supply pump 81 and the water supply pipe 82 constitute a second water supply unit that supplies water as a slurry material to the mixing tank 20 through a pipe that opens to the mixing tank 20.

  High pressure water sprayed from the first nozzle 51a or the second nozzle 51b hits the inner surface of the upper surface portion 22 and the inner surface of the main body portion 21 in the circumferential direction, and the fixed matter is peeled off. Also, the high-pressure water sprayed from the third nozzle 51c hits the bottom surface portion 23, and the fixed matter is peeled off. In this way, the inside of the mixing tank 20 is cleaned by removing the fixed matter. Moreover, after the high pressure water sprayed from each nozzle 51a-51c is utilized for washing | cleaning, it accumulates in the mixing tank 20 with the water supplied by the water supply pump 81, and a water level rises gradually (water Storage step). On the liquid surface, the cleaning in the mixing tank 20 is continued. Note that high-pressure water continues to be ejected from the nozzle 51 even under the liquid level. In the present embodiment, the inner surface of the mixing tank 20 is washed while supplying water used for producing cement milk to the mixing tank 20.

  In step ST3, the control unit 55 measures the water in the mixing tank 20 based on the output signal of the load sensor 58, and determines whether or not the weight of the water has reached the set weight (the liquid level has reached a predetermined water level). Whether or not). Step ST3 is repeated until it is determined that the weight of water has reached the set weight. When it is determined that the weight of water has reached the set weight, the control unit 55 stops the water supply pump 81 and the first pump 52 in step ST4, and immediately after that, closes the first electromagnetic valve 71. Switch. Thereby, the supply of water from the water supply pipe 82 and the injection of high-pressure water (that is, the cleaning operation) by the nozzles 51a to 51c are stopped, and the supply of water to the mixing tank 20 is completed. In the mixing tank 20, as shown in FIG.4 (c), the water has accumulated to the upper end of the main-body part 21. As shown in FIG.

  Moreover, the control part 55 performs step ST5 immediately after step ST4, switches the 2nd solenoid valve 72 to an open state, and starts the 2nd pump 53 immediately after that. Thereby, the 2nd pump 53 discharges the air suck | inhaled from the circumference | surroundings. As shown in FIG. 4C, the discharged air sequentially flows through the second branch pipe 62, the downstream portion of the branch portion of the connection pipe 60, and the in-shaft channel 31a, and enters each nozzle 51a to 51c. Distributed. Each nozzle 51a-51c injects air. Therefore, the water accumulated in the mixing tank 20 does not flow into the nozzles 51a to 51c. In the present embodiment, a gas supply unit that supplies gas to each of the nozzles 51a to 51c is provided by the second pump 53, the second branch pipe 62, the downstream portion of the branch portion of the connection pipe 60, and the in-shaft channel 31a. It is configured.

  Subsequently, in step ST6, the control unit 55 sequentially inputs an admixture, bentonite, and cement to the mixing tank 20 as cement milk materials other than water. Each of these materials is charged by a set weight based on the output signal of the load sensor 58 (material supply step). In the material supply step, the control unit 55 sequentially controls the admixture supply unit, the bentonite supply unit, and the hopper 28. Since the blade 32 is rotated together with the shaft 31 by the motor 33a, water, cement, bentonite and admixture are stirred by the blade 32 (stirring step). In the stirring step, air is supplied to the nozzles 51a to 51c. In addition, the control part 55 switches the hopper 28 to a closed state, after throwing in all the cement. Moreover, the control part 55 starts the timer which measures stirring time after completion | finish of injection | throwing-in of all the materials.

  Subsequently, in step ST7, the control unit 55 sets the condition that the above-mentioned timer has expired as the discharge condition for discharging cement milk from the mixing tank 20, and the water level below which the storage tank 40 can input cement milk. It is determined whether or not both of the conditions are satisfied. An output signal of the water level sensor of the storage tank 40 is input to the control unit 55. Step ST7 is repeated until it is determined that the discharge condition is satisfied. When it is determined that the discharge condition is satisfied, the control unit 55 switches the discharge valve 29 to the open state in step ST8, and the mixing tank 20 moves to the storage tank 40 as shown in FIG. Drain the cement milk. Further, the motor 33a of the driving device 33 is stopped.

  Subsequently, the control unit 55 waits for a predetermined time (time required for all cement milk to be discharged from the mixing tank 20) from the execution of step ST8, performs step ST9, and stops the second pump 53. Immediately thereafter, the second electromagnetic valve 72 is switched to the closed state, and the discharge valve 29 is also switched to the closed state.

  Subsequently, in step ST10, the control unit 55 determines whether or not there is a stop operation for stopping the mixing system 10. If it is determined that there is a stop operation, the control unit 55 ends the system control process. On the other hand, if it determines with there being no stop operation, the control part 55 will return to step ST1. In the system control process, steps ST1 to ST10 are repeated until it is determined in step ST10 that there is a stop operation. Thereby, the cement milk is repeatedly manufactured in the mixing tank 20. According to the mixing system 10, the production of cement milk and the cleaning of the mixing tank 20 can be performed fully automatically. In the present embodiment, the operations of the first pump 52 and the second pump 53 are performed alternately without leaving time. And

[4. Effects of embodiment, etc.]
In the present embodiment, a gas supply unit that supplies air to the nozzles 51a to 51c is provided in order to prevent clogging of the nozzles 51a to 51c. And in the mixing tank 20, the control part 55 is each between the end time of the period which accumulate | stores the high pressure water injected from each nozzle 51a-51c as a material of cement milk, and the discharge completion time of cement milk. The second pump 53 is controlled so that air is supplied to the nozzles 51a to 51c. Therefore, it is possible to suppress the cement milk from flowing into the nozzles 51a to 51c without changing the concentration of the cement milk in a state where the cement milk is accumulated in the mixing tank 20. The gas supply unit that does not change the concentration of cement milk can be used even in a state where the supply of cement milk from the mixing tank 20 to the cement milk supply place is temporarily stopped and waits, and the eyes of the nozzles 51a to 51c. Clogging can be suppressed.

  Moreover, in this Embodiment, the high pressure water injected from the nozzles 51a-51c is stored in the mixing tank 20 as a material of cement milk. Therefore, the mixing tank 20 can be cleaned using the manufacturing process of the cement milk while suppressing the cement milk from flowing into the nozzles 51a to 51c.

  Further, in the present embodiment, the upper surface portion 22 is formed in a dome shape so that the space on the liquid surface is widened, and the first nozzle 51a exists on the liquid surface so that the vicinity of the outer periphery on the inner surface of the upper surface portion 22 (many It is easy to clean the area where the sticking material adheres. In addition, since the second and third nozzles 51b and 51c are arranged at a position lower than the lower end of the upper surface portion 22, the inner surface of the mixing tank 20 can be cleaned in a wide range in the height direction. According to the present embodiment, it is possible to clean the inner surface of the mixing tank 20 over a wide range in the height direction, and it is possible to reliably clean a region where a large amount of fixed matter adheres.

  Moreover, in this Embodiment, in addition to the water injected from the nozzles 51a-51c, water is supplied as a material of cement milk from the water supply pipe 82 connected to the mixing tank 20. Therefore, it is possible to supply a quantity of water necessary for producing cement milk in a short time.

[5. Other variations]
In the above-described embodiment, cement or the like is added after the supply of water to the mixing tank 20 is completed. However, even if cement or the like is added before the water or during the period when the water is being supplied. Good. That is, the material supply step may be performed before the water storage step, or the material supply step may be performed during the water storage step.

  In the above-described embodiment, the nozzle 51 is directly attached to the shaft 31, but the nozzle 51 may be attached to the shaft 31 via an attachment member, or the nozzle 51 may be attached to a place other than the shaft 31. Good. For example, the nozzle 51 may be attached to the main body portion 21 of the mixing tank 20 or may be attached to the upper surface portion 22. In this case, the direction of the nozzle 51 may be changed automatically.

  In the above-described embodiment, the cleaning operation for cleaning the inner surface of the mixing tank 20 is performed in the process of manufacturing cement milk. However, the cleaning operation may be performed when cement milk is not manufactured.

  In the above-described embodiment, the upper surface portion 22 of the mixing tank 20 has a dome shape, but the upper surface portion 22 may have a flat plate shape.

  The present invention can be applied to a mixing system for producing cement milk by stirring water and cement.

DESCRIPTION OF SYMBOLS 10 Mixing system 20 Mixing tank 30 Stirrer 31 Shaft 31a Flow path in shaft (water supply part, gas supply part)
51 Nozzle 51a 1st nozzle 51b 2nd nozzle 51c 3rd nozzle 52 1st pump (water supply part)
53 Second pump (gas supply part)
55 Control unit 60 Connection piping (water supply unit, gas supply unit)
61 First branch pipe (water supply section)
62 Second branch pipe (gas supply part)

Claims (7)

A mixing tank for mixing liquids;
A stirring device for stirring the liquid in the mixing tank;
A mixing system for producing a slurry by stirring water and cement in the mixing tank by the stirring device,
A nozzle provided in the mixing tank so as to spray water toward the inner surface of the mixing tank;
A water supply section for supplying high-pressure water to the nozzle;
A mixing system comprising: a gas supply unit that supplies gas to the nozzle in order to prevent clogging of the nozzle.   In the mixing tank, the gas supply unit is configured so that gas is supplied to the nozzle after the period in which the high-pressure water sprayed from the nozzle is accumulated as the material of the slurry ends until the slurry is discharged. The mixing system according to claim 1, further comprising a control unit that controls. The mixing tank is formed in a dome shape on the upper surface portion that closes the upper side,
In the mixing tank, a plurality of nozzles are provided,
The plurality of nozzles include a nozzle disposed at a position lower than a lower end of the upper surface portion, and a nozzle disposed at a position higher than the lower end of the upper surface portion. As described in the mixing system. In the mixing tank, a plurality of nozzles are provided,
3. The mixing system according to claim 1, wherein the plurality of nozzles include a nozzle disposed in a lower portion of an indoor space of the mixing tank and a nozzle disposed in an upper portion of the indoor space. .   5. The apparatus according to claim 1, further comprising a second water supply unit that supplies water as a material of the slurry to the mixing tank through a pipe that opens to the mixing tank. The described mixing system. A mixing tank cleaning device for cleaning the inside of a mixing tank in which slurry is produced by stirring water and cement,
A nozzle provided in the mixing tank so as to spray water toward the inner surface of the mixing tank;
A water supply section for supplying high-pressure water to the nozzle;
A gas supply unit that supplies gas to the nozzle to prevent clogging of the nozzle;
A mixing tank cleaning apparatus, wherein the mixing tank is cleaned with high-pressure water sprayed from the nozzle. A slurry production method for producing a slurry by stirring water and cement,
A water storage step of injecting high-pressure water as a slurry material from a nozzle provided in the mixing tank toward the inner surface of the mixing tank, and storing the injected water in the mixing tank;
A material supplying step of supplying a slurry material other than water to the mixing tank;
After the water storage step and the material supply step, perform a stirring step of stirring the liquid in the mixing tank,
In the stirring step, a gas is supplied to the nozzle.

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