JP7487912B2 - How to remove stuck-on material - Google Patents

Description

The present invention relates to a method for removing stuck-on matter.

As a method for removing material stuck to the surface of an object, for example, a method is known in which the material is burned by heating the object, but such a method often causes damage to the object. Another method is known in which a flow of granular dry ice is collided with the material stuck to the surface of the object, but such a method has problems such as high processing costs and also has the risk of causing damage to the object.

A cleaning device that cleans an object with a cleaning liquid containing air bubbles is known from JP 2016-209807 A.

JP 2016-209807 A

The cleaning device disclosed in the above patent publication is an extremely effective device. However, it can be difficult to remove solid matter that has firmly adhered to an article. For example, it takes a very long time and a huge amount of effort to remove plastic material that has welded to the surface of a screw built into a heating cylinder installed in an injection molding machine, or solid matter that has adhered to the kneading blades of a kneader or the mixing blades of a mixer.

SUMMARY OF THE PRESENT DISCLOSURE ... An object of the present invention is to provide a method for removing adherent matter, which can reliably, quickly and easily remove adherent matter adhered to the surface of an article.

In order to achieve the above object, the method for removing a stuck-on substance of the present invention is a method for removing a stuck-on substance stuck to a surface of an article, comprising the steps of:
After cracks are formed in the adherent material, a flow of the remover liquid containing air bubbles is collided with the adherent material, causing the adherent material to peel off from the surface of the article.

In order to achieve the above object, the present invention provides an apparatus for removing stuck matter that has adhered to a surface of an article, the apparatus comprising:
(A) a storage tank for storing the removal solution;
(B) a pump;
(C) a removal container in which the removal nozzle is disposed and which stores the object; and
(D) a removal liquid supply system connecting the pump and the removal nozzle;
Equipped with
The pump is
(B-1) a suction section for sucking the removal liquid stored in the storage tank;
(B-2) a gas suction part attached to the suction part for taking in gas into the suction part; and
(B-3) a delivery unit connected to a removal liquid supply system for delivering the removal liquid to the removal nozzle;
Equipped with
The pump mixes the gas taken in through the gas suction unit with the removal liquid from the storage tank to make the removal liquid contain air bubbles, and delivers the removal liquid to the removal nozzle through the delivery unit.
The removal nozzle causes a flow of removal liquid containing air bubbles to collide with the adherent material.

In the method for removing the adherent matter of the present invention, by maintaining the adherent matter and the part of the article to which the adherent matter is adhered at a desired temperature, it is possible to form a crack (low-temperature brittle crack) in the adherent matter due to the difference between the linear expansion coefficient of the adherent matter and the linear expansion coefficient of the part of the article to which the adherent matter is adhered. In this case, the desired temperature is preferably a temperature of 0 degrees or lower, and further, the desired temperature can be achieved by immersing the adherent matter and the part of the article to which the adherent matter is adhered in a liquid, and further, in some cases, the liquid can have the same components as the main components of the removal liquid. In some cases, the desired temperature can be achieved by spraying a gas (air) onto the adherent matter and the part of the article to which the adherent matter is adhered.

Alternatively, the method for removing adherent material of the present invention can be configured to generate cracks in the adherent material by immersing the adherent material and the part of the article to which the adherent material is adhered in a chemical, in which case the chemical can be configured to contain ozone or hydrogen peroxide.

Furthermore, in the method for removing stuck-on material of the present invention including the preferred embodiment described above,
A suction section for sucking up the removal liquid;
A gas suction portion attached to the suction portion for taking in gas into the suction portion; and
A delivery section for discharging the removal solution;
A pump having
The pump can mix gas taken in through the gas suction section with the removal liquid to make the removal liquid contain air bubbles, and then the removal liquid can be delivered through the delivery section, so that the flow of the removal liquid containing the air bubbles collides with the solidified material.

The removal liquid circulation system includes a gas suction unit that connects the storage tank and the suction unit of the pump, and also connects the delivery unit of the pump and the storage tank, and is disposed near the suction unit of the pump. The gas suction unit disposed near the suction unit of the pump can be composed of, for example, a pipe attached to the removal liquid circulation system near the suction unit of the pump, and a valve (specifically, for example, an electromagnetic valve). With the valve in an open state, gas (specifically, for example, air) can be introduced or injected from the pipe into the removal liquid circulation system. Bubbles can be formed in the removal liquid simply by driving the pump. As an example of the pump, a centrifugal pump that has few malfunctions and can easily form bubbles in the removal liquid can be exemplified, but is not limited to this, and for example, a cyclone type pump can be exemplified. In short, any type of pump can be used as long as it can reliably form bubbles in the removal liquid.

Alternatively, the liquid may be a chemical for generating cracks in the bond, in which case the chemical may include ozone or hydrogen peroxide. Alternatively, liquid nitrogen may be used to cool the article, generating cracks in the bond based on low-temperature brittleness.

Furthermore, in the method for removing adherent material of the present invention including the preferred embodiment described above , the remover may be in a form containing water or ethyl alcohol. Water containing 30% ethyl alcohol is at -14°C to -15°C, and water containing 99% ethyl alcohol is at approximately -50°C, so the amount of ethyl alcohol to be mixed with water may be determined based on the desired temperature. The remover may contain, for example, ozone or hydrogen peroxide, or may contain citric acid, oxalic acid, sodium bicarbonate (sodium bicarbonate), acetic acid, sodium hydroxide, or hypochlorous acid. In some cases, the remover may contain, for example, a rust-preventive treatment agent mainly composed of nitrous acid and an organic carboxylic acid azole compound, or a desired treatment agent.

The removal nozzle can be composed of an ejector. The ejector has a drive port, a suction port, and a discharge port, and the drive port and the suction port are connected to the delivery section of the pump. Based on the suction force generated in the ejector by the removal liquid containing air bubbles that is pumped from the delivery section of the pump to the drive port of the ejector, the removal liquid containing air bubbles is sucked into the suction port from the delivery section of the pump, and is discharged from the drive port of the ejector together with the removal liquid that is pumped to the drive port of the ejector, colliding with the solidified material.

In the method for removing a solidified material of the present invention including the various preferred forms and configurations described above, the diameter of the bubbles is preferably 50 μm or less. Here, the diameter of the bubbles is an average diameter, and includes cases where the diameter is strictly 50 μm or less, as well as cases where the diameter is substantially 50 μm or less, and the presence of variations caused by various factors is allowed. The diameter of the bubbles is the value in the removal liquid discharged from the delivery part of the pump. Bubbles with a diameter of 50 μm or less are also called "microbubbles", and they gradually become smaller in the process of being crushed, and penetrate into cracks generated in the solidified material, so that the solidified material can be destroyed from the inside.

The removal container may be provided with a removal liquid discharge section for discharging the removal liquid from the removal container, or may be provided with a liquid/chemical discharge section for discharging the liquid/chemical from the removal container.

The removal liquid recovery system can be configured to include a filter section. If the removal liquid discharged from the removal container is filtered by the filter section and then returned to the storage tank, the filter section can remove the stuck-on materials, making it possible to reuse the removal liquid and reducing the cost (processing cost) of removing the stuck-on materials from the articles. The filter section can be a filter of known configuration and structure.

The liquid/chemical supply system includes a liquid/chemical storage tank and a liquid/chemical inlet section. The liquid/chemical inlet section for introducing the liquid or chemicals supplied from the liquid/chemical storage tank into the removal container is connected midway through the removal liquid supply system. If the liquid or chemicals discharged from the removal container are filtered by the filter section and then returned to the liquid/chemical storage tank, the filter section can remove any stuck-on material, making it possible to reuse the liquid or chemicals and reducing the cost (processing cost) of removing stuck-on material from the object. The filter section can be a filter of known configuration and structure.

It is preferable that each of the storage tank, removal container, and liquid/chemical storage tank is equipped with a temperature control device to control the temperature of the removal liquid, liquid, and chemicals. Examples of temperature control devices include a temperature regulator, chiller, cooling device, refrigeration device, and boiler.

The storage tank and the liquid/chemical storage tank can be made from metal, alloy, or plastic materials. The storage tank and the liquid/chemical storage tank can be open to the atmosphere. Parts of the removal liquid supply system, removal liquid recovery system, removal liquid circulation system, liquid/chemical supply system, and liquid/chemical recovery system can be composed of piping (pipes) made of, for example, metal, alloy, or plastic.

Examples of combinations of articles and stuck-on materials include (a screw built into the heating cylinder of an injection molding machine used for injection molding, etc., thermoplastic resin), (containers and conveying devices in the food manufacturing field, mixing devices, starch). The stuck-on material removal method and stuck-on material removal device of the present invention can also be applied to removing stuck-on materials from various filters used in various fields, removing stuck-on materials from mirror-finished surfaces of mirror-finished metal or alloy articles used in various fields, and removing stuck-on materials in pores (e.g., pores with a diameter of 0.3 mm or less) opened in articles used in various fields. Examples of articles include kneading blades of a kneader and mixing blades of a mixer.

In the method for removing a solid object of the present invention, after a crack is generated in the solid object, a flow of a removal liquid containing air bubbles is collided with the solid object, and the solid object is peeled off from the crack from the surface of the object, so that the solid object adhered to the surface of the object can be reliably, quickly, and easily removed without damaging the object. In addition, since the method does not cause corrosion on the surface of the object and only removes the solid object adhered to the surface of the object, it does not create a breeding ground for germs or bacteria on the surface of the object. Note that the effects are not necessarily limited to those described here, and any of the effects described in this specification may be used. In addition, the effects described in this specification are merely examples, and are not limited thereto, and additional effects may be used.

FIG. 1 is a conceptual diagram of a solid matter removal device used in the solid matter removal method of the first embodiment of the present invention. FIG. 2 is a conceptual diagram of a modified example of the adherent material removal device used in the adherent material removal method of the invention according to the first embodiment. FIG. 3A is a diagram showing a process in which the removal liquid becomes bubbles by the action of a pump, and FIG. 3B is a diagram showing the principle of an ejector. FIG. 4 is a schematic diagram showing how the internal pressure of a minute bubble gradually increases as the volume of the bubble decreases, and finally, when the internal pressure reaches a maximum, the bubble collapses and disappears. 5A, 5B, 5C, and 5D are schematic partial cross-sectional views of an article, a fixed object, and the like, illustrating the fixed object removal method of the first embodiment. FIG. 6 is a conceptual diagram of a slurry ice production apparatus according to the second embodiment, including a conceptual diagram of a pressure reducing device. FIG. 7 is a schematic cross-sectional view of an air bubble generation chamber provided in the slurry ice production apparatus of the second embodiment. FIG. 8 is a diagram showing the state of plastic material (adhered matter) that has adhered (welded) to the surface of a screw (article) built into a heating cylinder provided in an injection molding device, and a diagram showing the state after the plastic material (adhered matter) has been removed from the surface of the screw (article) by the adhered matter removal method of Example 1.

The present invention will be described below based on examples with reference to the drawings, but the present invention is not limited to the examples, and the various numerical values and materials in the examples are merely examples. In the following description, the same elements or elements having the same functions will be designated by the same reference numerals, and duplicate descriptions will be omitted.

Example 1 relates to a method for removing stuck-on material of the present invention. In Example 1, the article is composed of a screw built into the heating cylinder of an injection molding machine used for injection molding and the like. Note that, when removing the stuck-on material, the screw is removed from the heating cylinder. Thermoplastic resin used in injection molding, for example, polycarbonate resin, is stuck to the surface of the screw (part of which is shown) as stuck-on material (see the left hand portion of FIG. 8). The stuck-on material removal device removes the stuck-on material stuck to the article (see the right hand portion of FIG. 8). Note that, in FIG. 1, the article is shown as a flat plate for the sake of simplicity.

A conceptual diagram of the adhesion removal device of Example 1 is shown in Figure 1. Figure 3A shows the process in which the removal liquid turns into bubbles by the action of the pump. Furthermore, Figure 4 shows a schematic diagram of how the internal pressure of the bubbles gradually increases as the volume of the fine bubbles decreases, and how the bubbles finally collapse and disappear when the pressure reaches a maximum. Figures 5A, 5B, 5C, and 5D show a schematic diagram of how the fine bubbles diffuse and penetrate into the cracks, peeling off the adhesions from the surface of the article.

The adherent substance removal device 10 used in the adherent substance removal method of the first embodiment is a adherent substance removal device that removes adherent substances (or contaminants) 81 adhered to the surface of an article (object) 80,
(A) a storage tank 11 for storing a removal solution 12;
(B) pump 21,
(C) a removal container 41 in which the removal nozzle 50 is disposed and which stores an item (object) 80; and
(D) a removal liquid supply system 30 connecting the pump 21 and the removal nozzle 50;
Equipped with
The pump 21 is
(B-1) a suction unit 21A that sucks the removal liquid 12 stored in the storage tank 11;
(B-2) a gas suction part 22 attached to the suction part 21A for taking in gas (specifically, air) into the suction part 21A; and
(B-3) a delivery unit 21B connected to the removal liquid supply system 30 to deliver the removal liquid 12 to the removal nozzle 50;
It is equipped with:

The removal liquid circulation system 20 connects the storage tank 11 to the suction part 21A of the pump 21, and also connects the delivery part 21B of the pump 21 to the storage tank 11, and is equipped with a gas suction part 22 arranged near the suction part 21A of the pump 21. The pump 21 mixes the gas (specifically, for example, air) taken in through the gas suction part 22 with the removal liquid 12 from the storage tank 11 to make the removal liquid 12 contain air bubbles, and delivers the removal liquid 12 to the removal nozzle 50 through the delivery part 21B. That is, air bubbles are formed in the removal liquid 12 in the pump 21. The removal nozzle 50, which has a known configuration and structure, causes the flow of the removal liquid 12 containing air bubbles (indicated by arrows in FIG. 1) to collide with the solidified material 81. In this way, by performing the stripping operation with the removal liquid 12 containing fine air bubbles, a greater stripping effect can be obtained than when performing the stripping operation with a removal liquid that is only liquid.

Specifically, the pump 21 functions to mix gas into the removal liquid 12 in the storage tank 11 to form bubbles, and then to repeat the circulation process of returning the liquid to the storage tank 11 under pressure, thereby causing the removal liquid 12 in the storage tank 11 to contain fine bubbles (microbubbles). By repeating the circulation process, the bubbles become finer (microbubbles).

That is, the pump 21, which is a centrifugal pump, has a stirring action of sucking the removal liquid 12 from the storage tank 11 and mixing (injecting) the gas (air) taken in through the gas suction part 22 into the sucked removal liquid 12. The gas suction part 22 is disposed in the front part of the removal liquid circulation system 20 that connects the storage tank 11 and the suction part 21A of the pump 21. Specifically, the gas suction part 22 is disposed near the suction part 21A of the pump 21. More specifically, the gas suction part 22 is composed of a pipe 23A attached to the removal liquid circulation system 20 near the suction part 21A of the pump 21, and a valve (specifically, for example, an electromagnetic valve 23B). The amount of gas mixed in (injected) can be adjusted based on the opening and closing degree of the electromagnetic valve 23B. The electromagnetic valve 23B is appropriately opened, gas (specifically, air) is introduced and injected into the removal liquid circulation system 20 from the pipe 23A, and the pump 21 is driven to form bubbles in the removal liquid 12. A shutoff valve 26 is provided in the removal liquid circulation system 20 (the latter part of the removal liquid circulation system 20) connecting the delivery part 21B of the pump 21 and the storage tank 11, and the flow of the removal liquid 12 from the delivery part 21B of the pump 21 to the storage tank 11 can be shut off as desired. In addition, a bypass path 24 is provided between the delivery part 21B of the pump 21 and the removal liquid supply system 30, and an auxiliary valve 25 is provided in the bypass path 24. A part of the removal liquid 12 containing bubbles discharged from the delivery part 21B is returned to the storage tank 11, and the remainder is sent to the removal nozzle 50.

Here, the diameter of the bubbles is preferably 50 μm or less. The pressure of the removal liquid 12 discharged from the removal nozzle 50 can be, for example, 0.2 MPa to 0.8 MPa in terms of gauge pressure. The temperature of the removal liquid 12 may be, for example, 0 degrees or less. Specifically, the pressure of the removal liquid 12 discharged from the removal nozzle 50 is set to 0.5 MPa in terms of gauge pressure.

Ethyl alcohol cooled to -14°C to -15°C was used as the removal solution 12.

The removal liquid supply system 30 is composed of piping 31, which is provided with a flow control valve 33 that controls the flow rate of the removal liquid 12.

The device 10 used in the method for removing a fixed object according to the first embodiment further includes a liquid supply system 70 for supplying a liquid (or a chemical) 72 to the removal container 41 in order to cause a crack 82 in the fixed object 81. The liquid/chemical supply system 70 includes a liquid/chemical storage tank 71, a liquid/chemical inlet 73, and a valve 74. The liquid/chemical inlet 73 for introducing the liquid (or chemical) supplied from the liquid/chemical storage tank 71 via a pump (not shown) into the removal container 41 is connected to the middle of the removal liquid supply system 30. In order to cause a crack 82 in the fixed object 81, the liquid 72 adjusts the temperature of the fixed object 81 and the part of the article 80 to which the fixed object 81 is attached in the removal container 41 to a desired temperature. Here, the desired temperature is a temperature at which the crack 82 occurs in the fixed object 81 due to the difference between the linear expansion coefficient of the fixed object 81 and the linear expansion coefficient of the part of the article 80 to which the fixed object 81 is attached. The desired temperature may be a temperature below 0 degrees.

The removal container 41 is provided with a liquid/chemical discharge section 75 and a valve 76 for discharging the liquid (or chemical) 72 from the removal container 41, and the liquid (or chemical) 72 is returned to the liquid/chemical storage tank 71. The liquid/chemical storage tank 71 is provided with a temperature control device (not shown), which can control the temperature of the liquid 72 to a desired temperature. Ethyl alcohol cooled to -14°C to -15°C was used as the liquid 72 for temperature control. That is, in Example 1, the liquid and chemicals are configured to have the same components as the main components of the removal liquid. The temperature of the liquid 72 can be controlled by measuring the temperature of the liquid 72 in the liquid/chemical storage tank 71 with a temperature sensor and controlling it to the set temperature with a refrigerator, chiller, etc. (not shown).

The removal liquid recovery system 60 is composed of a removal liquid discharge section 61, a valve 62, and a filter section 63. The removal liquid discharge section 61, which discharges the used removal liquid 12 from the removal container 41, is attached to the removal container 41, and a valve 62 is attached to the removal liquid discharge section 61. The filter section 63, which filters the removal liquid 12, removes the stuck-on substances and the like contained in the used removal liquid 12. If the removal liquid 12 discharged from the removal container 41 is filtered by the filter section 63 and then returned to the storage tank 11, the stuck-on substances 81 and the like can be removed by the filter section 63, making it possible to reuse the removal liquid 12 and reducing the cost (processing cost) of removing the stuck-on substances 81 from the item 80.

The removal container 41 is fitted with a temperature control device 42 for maintaining the liquid 72 in the removal container 41 at a desired temperature (e.g., -14°C to -15°C).

The method for removing the adherent matter in Example 1 is a method for removing the adherent matter adhered to the surface of an article (object) 80, in which a crack 82 is generated in the adherent matter 81, and then a flow of the removal liquid 12 containing air bubbles is collided with the adherent matter 81, thereby peeling the adherent matter 81 from the surface of the article (object) 80.

Specifically, by maintaining the adhesion 81 and the part of the article 80 to which the adhesion 81 is adhered at a desired temperature, or more specifically, by cooling the adhesion 81 and the part of the article 80 to which the adhesion 81 is adhered, a crack 82 is generated in the adhesion 81 due to the difference between the linear expansion coefficient of the adhesion 81 and the linear expansion coefficient of the part of the article 80 to which the adhesion 81 is adhered. The desired temperature is a temperature below 0 degrees. The adhesion 81 and the part of the article 80 to which the adhesion 81 is adhered are immersed in the liquid 72 to bring them to the desired temperature.

More specifically, an object 80 is placed in a removal container 41 (see FIG. 5A). Then, a liquid 72 is introduced into the removal container 41 from a liquid/chemical storage tank 71 via a pump (not shown) through a liquid/chemical inlet 73, a valve 74, and the removal liquid supply system 30 (see FIG. 5B). As described above, the temperature of the liquid 72 is −14° C. to −15° C. As a result, due to the difference between the iron screw (linear expansion coefficient 11.7×10 ⁻⁶ /K) and the polycarbonate resin (linear expansion coefficient 70×10 ⁻⁶ /K), the polycarbonate resin shrinks, and a crack 82 occurs in the adherent 81 (see FIG. 5C).

Then, the liquid 72 in the removal container 41 is returned to the liquid/chemical storage tank 71 via the liquid/chemical discharge section 75 and the valve 76. In this state, the flow of the removal liquid 12 containing air bubbles is collided with the solidified matter 81. Specifically, the pump 21 is operated to mix gas into the removal liquid 12 in the storage tank 11 to form air bubbles, and the circulation process of returning the liquid to the storage tank 11 in a pressurized state is repeated, so that the removal liquid 12 in the storage tank 11 contains fine air bubbles (microbubbles). The air bubbles are made fine (microbubbled) by repeating the circulation process. Here, the diameter of the air bubbles is preferably 50 μm or less. The removal liquid 12 containing air bubbles is then sent from the delivery section 21B to the removal nozzle 50 via the bypass path 24, the auxiliary valve 25, and the removal liquid supply system 30, and the flow of the removal liquid 12 containing air bubbles is caused to collide with the solidified matter 81 (see FIG. 5D).

More specifically, as shown in FIG. 3A, air is mixed into the removal liquid 12 sucked from the storage tank 11 by the pump 21, so that the removal liquid 12 contains air bubbles. The removal liquid 12 containing air bubbles is then returned to the storage tank 11. In this way, by repeating the circulation process of mixing air into the removal liquid 12 sucked from the storage tank 11 by the pump 21 and returning it to the storage tank 11 in a pressurized state, the removal liquid 12 in the storage tank 11 is maintained in a state containing air bubbles (microbubbles).

The peeling effect of fine bubbles (microbubbles) will be specifically described below. That is, fine bubbles have the property of changing their volume to a minimum due to surface tension (self-pressurizing). The pressure inside the bubbles increases as the bubble diameter becomes smaller. As shown in FIG. 4, the internal pressure gradually increases as the volume of the fine bubbles becomes smaller, and finally the pressure reaches a maximum and the bubbles collapse and disappear. By utilizing the energy of the shock wave generated at this time, it is possible to peel off the adhered object 81 from the object 80 while applying an impact to the adhered object 81 adhered to the object 80, more specifically, while applying an impact to the interface between the object 80 and the adhered object 81 through the crack portion 82.

Also, the fine bubbles have an aspect of being negative colloids and are negatively charged. And the fine bubbles are attracted to positively charged organic and inorganic matter. Therefore, the fine bubbles bond (attach) to the surface of the adherent, and then the fine bubbles diffuse and penetrate into the cracks generated in the adherent, destroying the adherent 81 from the cracks 82. And, because of this action, the peelability of the adherent 81 from the adhesion surface (interface) is increased, so that the adherent 81 adhered to the object 80 can be peeled off more reliably. Also, because the fine bubbles are negatively charged, the removing liquid 12 does not stick to the adherent 81, and because the removing liquid 12 has a smooth slurry-like fluidity, it is easy to blend with the object 80 and the adherent 81, and the peeling effect of the adherent 81 from the object 80 can be increased. Furthermore, the presence of air bubbles provides uniformity in the temperature of the removal liquid 12 and also has the effect of suspending objects in the removal container.

As described above, in the method for removing stuck-on material in Example 1, after a crack is created in the stuck-on material, a flow of removal liquid containing air bubbles is collided with the stuck-on material, causing the stuck-on material to peel off from the surface of the article. Therefore, the stuck-on material adhered to the surface of the article can be reliably, quickly, and easily removed without damaging the article.

In addition, if ethyl alcohol is used for the removal liquid 12 or liquid 72, a sterilizing effect can be expected, which is effective in removing stuck-on materials from containers, conveying devices (e.g., screw conveyors), and mixing devices (mixing fins) in the food manufacturing, medical, and cosmetic manufacturing fields.

The left side of Figure 8 shows the state of the plastic material (adhered matter) that has adhered (melted) to the surface of the screw (article) built into the heating cylinder of the injection molding device, and the right side of Figure 8 shows the state after the plastic material (adhered matter) has been removed from the surface of the screw (article) using the method for removing adhered matter of Example 1. It can be seen from Figure 8 that the adhered matter has been removed from the surface of the article.

Instead of the removal nozzle 50 having a known configuration and structure, an ejector 51 can also be used. A conceptual diagram of the adhesion removal device of Example 1 is shown in Figure 2, and a principle diagram of the ejector 51 is shown in Figure 3B.

The ejector 51 has a drive port 52, a suction port 53, and a discharge port 54. The drive port 52 is connected to the delivery section 21B of the pump 21 via pipes 31 and 32B, and the suction port 53 is connected to the delivery section 21B of the pump 21 via pipes 31 and 32A. A shutoff valve 56 is provided midway along the pipe 32B.

The inside of the drive port 52 is shaped like a nozzle, with the inner diameter gradually decreasing from the open end 52A to the end 52B, reaching a minimum diameter at the end 52B. The reduced diameter section 55 has the same inner diameter as the end 52B of the drive port 52. The discharge port 54 has the opposite shape to the drive port 52, that is, the inner diameter gradually increases from the end 54B on the reduced diameter section side of the discharge port 54 to the open end 54A.

The removal liquid 12 containing bubbles is pumped from the delivery section 21B of the pump 21 to the drive port 52 of the ejector 51 through the pipes 31, 32B and the shutoff valve 56. The suction port 53 opens to the narrowed section 55. In the ejector 51, the removal liquid introduced from the drive port 52 heads toward the narrowed section 55. Since the inner diameter of the narrowed section 55 is narrowed, the flow rate of the removal liquid in the narrowed section 55 increases. Then, as the flow rate increases, the pressure in the narrowed section 55 decreases based on Bernoulli's theorem, so the pressure in the suction port 53 opening into the narrowed section 55 decreases, and the removal liquid that has passed through the pipes 31, 32A is sucked in. This sucked removal liquid is discharged from the discharge port 54 together with the removal liquid supplied to the drive port 52, and collides with the solidified material. In order to increase the impact force that the removal liquid 12 exerts on the stuck-on material when peeling it off from the object, the shutoff valve 56 may be operated to perform intermittent suction by the ejector. By performing intermittent negative pressure suction by the ejector, the impact force that is exerted on the stuck-on material can be increased, so that the stuck-on material can be more reliably peeled off from the object.

When such an ejector 51 is used, the pump 21 performs the following two functions. That is, as described above, the first function of the pump 21 is to mix air into the removal liquid 12 in the storage tank 11 to form bubbles, and to repeat the circulation process of returning the liquid to the storage tank 11 in a pressurized state, thereby causing the removal liquid in the storage tank 11 to contain fine bubbles (microbubbles). By using the removal liquid 12 containing fine bubbles, the adherent matter 81 can be reliably peeled off from the object 80. The second function of the pump 21 is to supply the removal liquid from the storage tank 11 in a pressurized state to the drive port 52 of the ejector 51, and to suck the removal liquid 12 in the storage tank 11 through the pipes 31 and 32A based on the Venturi effect.

The ejector 51 has no moving parts, so it is not damaged and is easy to maintain. Furthermore, because the removal liquid is used to suck the removal liquid, the removal liquid is not diluted and the concentration of the removal liquid can be kept constant.

In some cases, the ejector may be disposed independently of the removal liquid circulation system 20. In this case, the system is composed of a pipe connecting the storage tank 11 that stores the removal liquid 12 and the drive port 52 of the ejector 51, and a pump (a pump separate from the pump 21) that is disposed midway along the pipe and pressure-feeds the removal liquid 12 to the drive port 52 of the ejector 51.

To remove material that has adhered to the inner walls of a pipe, a removal nozzle 50 or ejector 51 that can be inserted into the pipe can be used.

Example 2 is a modification of Example 1. In Example 2, water containing ice particles (slurry ice) is used as the liquid, and slurry ice is produced based on the slurry ice production method using a slurry ice production device described below. Then, instead of ethyl alcohol at -14°C to -15°C, which is the liquid in Example 1, slurry ice is used to cool the item 80. Specifically, by cooling the adherent matter 81 and the part of the item 80 to which the adherent matter 81 is adhered with slurry ice, cracks 82 are generated in the adherent matter 81 due to the difference between the linear expansion coefficient of the adherent matter 81 and the linear expansion coefficient of the part of the item 80 to which the adherent matter 81 is adhered.

As shown in the conceptual diagram of FIG. 6, the slurry ice making apparatus of the second embodiment has the following features:
A chamber 110 for storing salt water;
A refrigerator 120 for cooling the salt water;
a saltwater circulation pipe for supplying saltwater to the chamber 110 and discharging saltwater from the chamber 110;
A pump 130 for circulating salt water, the pump 130 being disposed midway through the salt water circulation pipe and having a suction portion connected to the chamber 110 via the salt water circulation pipe; and
An air bubble supplying device 140 that is attached to the saltwater circulation pipe on the delivery section side of the pump 130 and adds bubbles mainly composed of nitrogen gas to the saltwater;
It is equipped with:

The salt water circulation pipe from the chamber 110 to the pump 130 (upstream salt water circulation pipe) is indicated by salt water circulation pipe 161, and the salt water circulation pipe on the suction side of the pump 130 (downstream salt water circulation pipe) is indicated by salt water circulation pipe 162. The salt water circulation pipe 162 branches into a first pipe 181, a third pipe 183, and a fourth pipe 184. The first pipe 181 is connected to the refrigerator 120 as described below, and salt water is supplied into the chamber 110 via the third pipe 183. The fourth pipe 184 is connected to the drive port 152 of the ejector 151 described later.

Furthermore, the slurry ice production apparatus of the second embodiment is
a first pipe 181 that branches off from the salt water circulation pipe 162 downstream of the air bubble supply device 140 and supplies salt water to the refrigerator 120; and
A second pipe 182 supplies salt water, which is supplied via the first pipe 181 and cooled by the refrigerator 120, to the chamber 110;
It further comprises:

The slurry ice production apparatus of Example 2 further includes an agitator 170 for agitating the salt water in the chamber 110, and a pressure reducing device 150 for reducing the pressure in the upper space 111 of the chamber 110.

Here, as shown in the conceptual diagram in Fig. 6, the pressure reducing device 150 is composed of an ejector (aspirator) 151 having a driving port (primary side) 152, a suction port (secondary side) 153, and a discharge port (suction side) 154. As described above, the driving port 152 is branched from the salt water circulation pipe 162 downstream of the air bubble supply device 140 and is connected to a fourth pipe 184 that supplies salt water to the driving port 152, and the suction port 153 is connected to the upper space 111 of the chamber 110 via a fifth pipe 185 (shown by a dotted line in Fig. 6). The discharge port 154 is connected to the salt water circulation pipe 161 on the suction part side of the pump 130 via a sixth pipe 186. The pressure in the upper space 111 of the chamber 110 may be lower than atmospheric pressure, and is preferably as lower than atmospheric pressure as possible. The pressure of the salt water discharged from the pump 130 is in the range of 0.2×10 ⁶ Pa to 0.6×10 ⁶ Pa, specifically, 0.4×10 ⁶ Pa, for example.

In the slurry ice production apparatus of the second embodiment, the air bubble supply device 140 is
A nitrogen gas source 141 including a nitrogen gas separation device having a nitrogen gas separation membrane for separating nitrogen gas from air; and
a bubble generation chamber 142 for mixing nitrogen gas from a nitrogen gas source 141 with salt water discharged from a pump 130 to generate bubbles in the salt water;
As shown in a schematic cross-sectional view of FIG. 7, the air bubble generation chamber 142 includes:
Nitrogen gas supply port 143,
Salt water inlet 144,
a first chamber 145 for mixing nitrogen gas and salt water;
A second chamber 146 having a plurality of suction side openings 147A and a plurality of discharge side openings 147B and communicating with the first chamber 145 via the suction side openings 147A; and
a third chamber 148 communicating with the second chamber 146 via the discharge side opening 147B and having a discharge portion 149;
It is composed of:

The nitrogen gas and salt water sent into the first chamber 145 from the nitrogen gas supply port 143 and the salt water supply port 144 swirl and mix in the first chamber 145, and enter the second chamber 146 that communicates with the first chamber 145 through the suction side opening 147A. The nitrogen gas and salt water are then mixed evenly in the second chamber 146, and enter the third chamber 148 that communicates with the second chamber 146 through the discharge side opening 147B. At the moment of entering the third chamber 148, fine bubbles mainly composed of nitrogen gas, for example, bubbles with a diameter of 2 μm, are generated in the third chamber 148 due to a sudden change in gas pressure. The nitrogen gas and salt water are then sent from the discharge port 149 to the salt water circulation pipe 162.

The sealed chamber 110 is made of, for example, stainless steel, the refrigerator 120 is a known refrigerator, the pipes 161, 162, 181, 182, 183, 184, 185, and 186 are made of, for example, stainless steel pipes, the pump 130 is made of, for example, a centrifugal pump, and the pressure reducing device 150 and the bubble generating chamber 142 are also made of stainless steel.

In the slurry ice production method of Example 2, the saltwater is cooled while air bubbles mainly composed of nitrogen gas are added to the saltwater in a circulating state.

That is, the slurry ice production method of Example 2 is as follows:
[First Stage]
Nitrogen gas-based bubbles are added to circulating salt water.
[Second Stage]
After the [first stage], the salt water is further cooled while continuing to circulate and continuing to add bubbles mainly composed of nitrogen gas, and maintaining this state.
The process includes the following steps.

In the slurry ice production method of Example 2, the atmosphere is reduced pressure in the circulating saltwater, and the saltwater is cooled while air bubbles mainly composed of nitrogen gas are added. Furthermore, the atmosphere is reduced pressure even before the air bubbles mainly composed of nitrogen gas are added. Also, the saltwater is continuously stirred while the saltwater is cooled while air bubbles mainly composed of nitrogen gas are added to the circulating saltwater.

Specifically, first, salt water in which a predetermined amount of sodium chloride is dissolved in drinking water is prepared and poured into the chamber 110. Also, valves 191, 192, 193, 194, 195, and 196 are closed. Then, the closed valves 191, 192, 193, 194, and 195 are opened, and the pump 130 is operated to start circulating salt water in the circulation path including the salt water circulation pipe 162, the third pipe 183, the chamber 110, and the salt water circulation pipe 161. At the same time, pressurized salt water is supplied from the salt water circulation pipe 162 to the drive port 152 of the ejector 151 constituting the pressure reducing device 150 via the fourth pipe 184, discharged from the discharge port 154, and sent back to the salt water circulation pipe 161 via the sixth pipe 186. In this way, the upper space 111 of the chamber 110 connected to the suction port (secondary side) 153 via the fifth pipe 185 is depressurized.

When the upper space 111 has reached the desired reduced pressure state, bubbles mainly composed of nitrogen gas are added to the salt water while continuing to reduce the pressure in the upper space 111. That is, the bubble supplying device 140 is operated to generate fine bubbles mainly composed of nitrogen gas in the bubble generating chamber 142, which are sent to the salt water circulation pipe 162, and the fine bubbles mainly composed of nitrogen gas are added to the salt water in the chamber 110 via the salt water circulation pipe 162 and the third pipe 183. The pressure of the salt water in the chamber 110 is 0.2×10 ⁶ Pa to 0.6×10 ⁶ Pa, specifically, for example, about 0.4×10 ⁶ Pa.

After continuing this operation for a desired time, i.e., after the desired time has elapsed in the [first stage], the [second stage] is executed. That is, while continuing to circulate the saltwater and continuing to add bubbles mainly composed of nitrogen gas, and while maintaining this state, the valve 196, which was in a closed state, is opened, the refrigerator 120 is operated, and the saltwater is cooled and supplied to the chamber 110 via the saltwater circulation pipe 162, the first pipe 181, the refrigerator 120, and the second pipe 182, and the saltwater in the chamber 110 is cooled, and the saltwater becomes slurry ice. Note that, as time passes, ice particles may begin to form in the saltwater. Even in such a case, by continuing to circulate the saltwater and continuing to add bubbles mainly composed of nitrogen gas, and maintaining this state, the generation of ice particles in the saltwater can be suppressed.

Here, it is preferable that the size of the bubbles is 50 μm or less. In addition, it is preferable that the nitrogen gas dissolution rate in the slurry ice is at least twice the nitrogen gas dissolution rate in the salt water before the nitrogen gas-based bubbles are added.

In this way, in the slurry ice production method of Example 2, the salt water is cooled while air bubbles mainly composed of nitrogen gas are added to the salt water in a circulating state. Therefore, the freezing point of the salt water is further lowered, the salt water is not frozen, and the water in the salt water is in a supercooled state. As a result, no ice particles are formed, and the slurry ice finally obtained is in a state similar to konjac (i.e., a viscous state or a thick viscous state) and does not contain ice particles. Therefore, it is possible to provide slurry ice that is less likely to damage the object to be cooled. Furthermore, the slurry ice production device of Example 2 is an apparatus that is extremely suitable for producing such slurry ice. The air bubble supply device 140 can also be applied to the solid matter removal device of Example 1.

Example 3 is also a modification of Example 1. In Example 3, a liquid, a chemical, is used to create cracks 82 in the adherent material 81. The chemical is water containing ozone or hydrogen peroxide. In the method for removing the adherent material of Example 3, the adherent material 81 and the part of the article 80 to which the adherent material 81 is attached are immersed in the chemical, thereby creating cracks 82 in the adherent material 81.

The removal liquid is mainly composed of _citric acid ( _C6H8O7 ). _That is, the removal liquid is obtained by dissolving citric acid or the like in water. In the solid matter removal device 10 of the third embodiment, by using citric acid as the main component of the removal liquid, the temperature of the removal liquid is raised by the circulation process, and as a result, the density of the removal liquid is increased. As a result, the removal liquid can be kept in a state containing air bubbles for a long time, and the amount of air bubbles generated is also increased. Furthermore, the air bubbles are made finer (microbubbles) by repeating the circulation process.

Apart from the above, the method for removing the stuck-on material in Example 3 can be substantially the same as the method for removing the stuck-on material in Example 1, so a detailed description will be omitted.

The present invention has been described above based on preferred embodiments, but the present invention is not limited to these embodiments. The configuration and structure of the adhesion removal device described in the embodiments are examples, and the removal solution, liquid, and chemicals are also examples and can be changed as appropriate, and the object and adhesion are also examples. In Example 1, the cracks were generated in the adhesion by cooling the object and adhesion, but it is also possible to generate cracks in the adhesion by heating the object and adhesion.

In the embodiment, the object with the adhered matter was stored in the removal container, but the removal container can be composed of a chamber (preferably equipped with a seal portion to prevent the removal liquid, liquid, or chemical from leaking from the object) that surrounds the object with the adhered matter, and after the liquid or chemical is pumped into the chamber and a crack is formed in the adhered matter, an ejector attached to the chamber can be used, for example, to collide a flow of the removal liquid containing air bubbles against the adhered matter, thereby peeling the adhered matter off from the surface of the object. If the chamber can be moved relative to the object with the adhered matter, it becomes possible to remove the adhered matter from a large object using a small chamber.

In some cases, the liquid or chemical may be configured to have the same main component as the removal liquid. Specifically, the liquid or removal liquid may be configured to have, for example, citric acid, baking soda, acetic acid, 5% or less sodium hydroxide aqueous solution, 5% or less hydrogen peroxide solution, and hypochlorous acid.

10: Adherent matter removal device, 11: Storage tank, 12: Removal liquid, 20: Removal liquid circulation system, 21: Pump, 21A: Suction section, 21B: Delivery section, 22: Gas suction section, 23A: Pipe, 23B: Valve (electromagnetic valve), 24: Bypass path, 25: Auxiliary valve, 30: Removal liquid supply system, 31, 32: Pipe, 33: Flow control valve, 41: Removal container, 42: Temperature control device, 50: Removal nozzle, 51: Edge vector, 52...drive port, 53...suction port, 54...discharge port, 55...reduced diameter section, 56...shutoff valve, 60...removed liquid recovery system, 61...removed liquid discharge section, 62...valve, 63...filter section, 70...liquid supply system (liquid/chemical supply device), 71...liquid/chemical storage tank, 72...liquid, 73...liquid/chemical inlet section, 74...valve, 75...liquid/chemical outlet section, 76...valve, 80...article (object), 81...adhered matter, 82...crack 1. A pump for supplying a gas bubble to a gas supplying chamber, comprising: a gas supplying portion for supplying a gas to the gas supplying portion; a cooling device for cooling the gas supplying portion; a nitrogen gas source for supplying a gas bubble to the gas supplying portion; a salt water supplying port for supplying salt water to the gas supplying portion; a pressure reducing device for reducing the pressure in the gas supplying portion; a pressure reducing device for reducing the pressure in the gas supplying portion; 152: Drive port (primary side), 153: Suction port (secondary side), 154: Discharge port (suction side), 161: Salt water circulation piping from the chamber to the pump, 162: Salt water circulation piping on the suction side of the pump, 170: Agitator, 181: First pipe, 182: Second pipe, 183: Third pipe, 184: Fourth pipe, 185: Fifth pipe, 186: Sixth pipe, 191, 192, 193, 194, 195, 196: Valves

Claims (5)

A method for removing a substance adhered to a surface of an article, comprising the steps of:
a step of immersing the adherent and the part of the article to which the adherent is adhered in a liquid maintained at a desired temperature in a container and maintaining the adherent and the part of the article to which the adherent is adhered at the desired temperature, thereby generating a crack in the adherent due to the difference between the linear expansion coefficient of the adherent and the linear expansion coefficient of the part of the article to which the adherent is adhered;
a step of causing a flow of the removal liquid containing negatively charged micro bubbles generated in a removal liquid supply system to collide with a positively charged adherent object, so that the micro bubbles adhere to the surface of the adherent object and diffuse and penetrate into the cracks generated in the adherent object;
a step of applying an impact generated by microscopic bubbles self-collapsed within the crack to the adherent material, thereby destroying the adherent material from the crack , and peeling the adherent material from the surface of the article. The method for removing a solid object according to claim 1 , wherein the liquid has the same main component as the removing liquid. 3. The method for removing stuck-on material according to claim 1, wherein the liquid contains ethyl alcohol maintained at a temperature of -14°C to -15°C. 2. The method for removing stuck matter according to claim 1, wherein the fine bubbles have a diameter of 50 μm or less. A suction portion that sucks the removal liquid;
A gas suction unit attached to the suction unit for taking in gas into the suction unit; and
A delivery unit that discharges the removal liquid;
A pump having
2. The method for removing a solid object according to claim 1, further comprising the steps of: mixing the gas taken in through the gas suction section with the removal liquid by the pump to cause the removal liquid to contain the microscopic bubbles; delivering the removal liquid through the delivery section; and colliding the flow of the removal liquid containing the microscopic bubbles with the solid object.

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