JPS6038624B2 - Ice slurry manufacturing equipment, ice blasting equipment and pipe cleaning equipment using this equipment - Google Patents

Description

[Detailed Description of the Invention] This invention provides a novel device for producing ice grains used in place of solids such as sand used in surface polishing operations such as liquid honing, sandblasting, and shot blasting, and a novel device using the same. In particular, ice slurry manufacturing equipment that can blow out liquid nitrogen into cold water, grow ice grains and float them to the surface, and continuously take out the ice grains without crushing them; and This obtained ice slurry is injected or sent to the object to be polished or the green pipe to be washed, and the used ice slurry is returned to the ice slurry manufacturing equipment again, creating a closed cycle system that does not allow foreign matter to enter from the outside. This invention relates to an ice brite device and pipe cleaning equipment that can save resources.

Generally speaking, liquid honing,
Sandblasting, shotblasting, etc. are used. Both of these methods spray solid materials such as abrasives, sand, and steel balls together with compressed air or high-pressure water to polish the surface of a steel plate or the like. However, these methods, typified by sandblasting, have various problems. In other words, dust pollution occurs and the cost of countermeasures is quite high, and it is difficult to implement in urban areas. Additionally, there is a shortage of waste sand disposal sites in the Tokyo metropolitan area, and disposal costs are rising every year. Furthermore, sand resources are becoming scarce and expensive, and high-quality sand is almost running out. In particular, depending on the construction location, transportation and supply of sand was hindered, making construction almost impossible. In addition, chemical cleaning methods or physical cleaning methods using air tools are employed as methods for cleaning special piping in nuclear power plants and the like. However, in the case of chemical cleaning, since chemicals enter the system, it is necessary to perform complete flushing, which not only increases time and cost, but also requires large-scale equipment, which poses a big problem along with the cost of processing waste liquid. On the other hand, in the case of air tool cleaning, there are restrictions on pipe diameter and pipe length, and furthermore, a flushing step after cleaning is essential, so the scope of its use is narrow. By the way, in recent years, ice blasting method (Special Publication No. 38713/1989) using dry ice grains or ice grains instead of the abrasive material, sand, etc. mentioned above has been developed.
and a pipe cleaning method (Special Publication No. 53-80) have been proposed. Both of these are designed to reduce waste by utilizing the vaporization or liquefaction of sprayed particles, and their usefulness is highly evaluated. However, because conventional manufacturing methods are used to produce dry ice grains and ice grains, their useful value has been halved. In this method, typified by the Ice Plast method, large blocks of ice are made at an ice factory and then mechanically crushed to obtain ice particles. For this reason, it is difficult to obtain uniform ice particles, and there is a large loss due to crushing, and in particular, when trying to make the particle size uniform, the recovery rate is drastically reduced. In addition, since ice cubes are usually produced in a remote location, transportation and storage are difficult and there are constraints on the construction site, and temporary storage in particular requires a considerable amount of cost. Furthermore, since the ice grain production system and the injection system are separate systems, the injected ice cannot be recovered and reused, making it impossible to conserve water and cold energy resources. There was a problem. Therefore, in view of the problems in the conventional ice grain grinding apparatus, the present inventors aimed to solve the problems effectively and came up with the present invention.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an ice slurry production apparatus capable of continuously producing ice grains and ice slurry by effectively exchanging heat between an ultra-low temperature liquid cryogen and cold water.

Another purpose is to configure an open cycle system with the ice slurry production equipment and ice injection equipment, to effectively clean steel plates and equipment without introducing foreign matter from the outside, and to conserve cold, heat, and water resources. To provide an ice blasting device that can be recovered and reused. Yet another purpose is to guide the ice grains or ice slurry IJ obtained by the ice slurry production apparatus to the piping to be cleaned, and to effectively return the ice slurry that flows out to the ice slurry production apparatus again to form a closed cycle. The present invention also provides a pipe cleaning device that can prevent pollution and save resources by making all routes sealed. Preferred embodiments of each device according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an embodiment of the ice slurry production apparatus of the present invention, and as shown in the figure, 1 is a cold water tank that stores cold water that has been cooled in advance to 0 DEG C. to 4 DEG C.

A constant water level is maintained by the detector 2, and when the constant water level is broken, the make-up water at room temperature stored in the make-up water tank 3 is sent to the cooling device 5 by the pump 4 and cooled, and becomes cold water at the above temperature and is automatically supplied. It is set up so that Reference numeral 6 denotes a small chamber which serves as an ice-making chamber provided at the lower part of the cold water tank 1, and is formed so that the cold water tank 1 is connected to the lower part and the upper part thereof so that cold water can freely enter and exit.

These chambers 4 and 6 are provided so that a liquid cryogen having an ultra-bottom temperature, such as liquid nitrogen, filled in a tank 7 or the like is continuously injected from the bottom. In addition, a strong boundary azusa wing 8 is provided inside the small chamber 6 as a rapid boundary means, and the injected liquid nitrogen is sufficiently mixed with the cold water 9, and nitrogen particles can be added to the cold water in order to improve heat exchange between the two. It is designed to disperse as many ice particles as possible and generate a large number of ice particles. Above the small chamber 6, that is, in the middle of the cold water tank 1, a weak boundary frame wing 10, which is a traverse speed concentration means, is provided with its blade extending from the upper lotus passage of the small chamber 6.

Reference numeral 11 denotes a middle chamber, which is provided so as to surround chambers 4 and 6 so that the weak border azusa wing 10 is exactly in the center, and whose bottom and upper part communicate with the cold water tank 1 in the same manner as the small chamber 6. is formed.

The cold water in the middle chamber 11 is generated by the weak boundary azusa blade 10 that promotes the vaporization of the liquid nitrogen particles formed in the small chamber, rapidly cooling the cold water around the particles and freezing them, thereby inhibiting the growth of ice particles. The acceleration replaces ice particles with the desired uniform size.・12 is a guide passage provided at the upper part of the cold water tank 1, which separates the ice grains 13 grown in the middle chamber 11 from the surrounding cold water and guides them upward through a small diameter guide passage from the upper part of the middle chamber 11. It becomes a pipe and extends above the water surface of the cold water tank 1. Reference numeral 14 denotes a take-out pipe arranged above the guide passage 12 so that the ice particles 13 or ice slurry floating in the guide passage 12 can be taken out continuously to the outside.

The operation of this device having the above configuration will now be described.

First, the liquid nitrogen injected from the liquid nitrogen tank 7 is poured into a barrel and mixed with the cold water that has been pre-cooled to 0 to 4 degrees Celsius and filled in the chamber 6 by the rapid rotation of the strong pestle blades 8. Ru. This mixing is sufficiently effective because the cold water in the chamber is separated from the cold water tank 1 by the partition wall, and causes fine particles of liquid nitrogen to be dispersed in the cold water and generate fine particles of ice due to heat exchange. These are the middle chamber 1 from above the small chamber 6.
1, but as long as liquid nitrogen is continuously injected, new cold water is constantly supplied from below the small chamber 6, so it is continuously generated and does not get stuck. The fine particles that have entered the middle chamber 11 are gently crushed by the weak crushing blades 10, so that the liquid nitrogen fine particles are promoted to vaporize and freeze the cold water around them, and the growth of ice particles is promoted to form ice. Becomes grains. Here, as in the small chamber 6, it is partitioned by a partition wall, so that the above-mentioned aphrodisiac effect is uniformly applied to the cold water in the middle chamber 11, and the particle size of the ice particles obtained thereby is also made uniform. Also, new cold water necessary for these ice particles is constantly supplied from below the middle chamber 11.

Therefore, the ice-making process requires only an extremely simple reaction process of simply bringing liquid nitrogen into contact with water, and since there is no complicated mechanism involved in the process, such as ice crushing or ice cutting, maintenance of the equipment is easy. Become.

Furthermore, it is possible to obtain ice grains having an appropriate particle size by adjusting the rotational speed of the cicada leaves 8, 10 and the injection speed of liquid nitrogen. Next, the ice grains 13 formed in the middle chamber 11 rise within the middle chamber 11 due to the difference in specific gravity, pass through the guide passage 12, and float and stack on the upper part thereof.

On the other hand, the nitrogen gas vaporized in the middle chamber 11 also rises and is exhausted from the upper end opening □ of the guide passage 12. Since the diameter of the guide passage 12 is smaller than that of the middle chamber 11, most of the cold water in the passage 12 is removed and replaced with ice particles, resulting in a dense ice slurry. The above nitrogen gas is the passage 1 where the ice grains are piled up.
2, which constantly rises and escapes from the ice slurry, prevents the bridging phenomenon of the ice slurry, and at the same time imparts its buoyancy to the ice particles, thereby having the effect of helping the ice particles rise. In addition, the guide passage 12
In order to prevent the ice particles inside from melting, it would be more effective if the walls of the passage 12 were preferably covered with a heat insulating layer, and a thawing heater was provided to eliminate the unstoppable bridging phenomenon. . Further, the floating ice grains 13 are taken out as ice grains or as ice slurry by the take-out pipe 14.

At this time, it is undesirable for nitrogen gas to get mixed into the take-out pipe 14, so it is preferable to provide a gas vent hole near the inlet. The decreased amount of cold water in the cold water tank 1 is immediately replenished by the make-up water tank 3 via the cooler 5, and is monitored by the detector 2 to maintain a constant water level at all times, and liquid nitrogen can also be continuously injected. Continuous operation of ice making is possible. Therefore, if an open cycle system is constructed to collect and reuse the water and cold energy without discarding the used ice slurry taken out from the take-out pipe 14, the small amount of cold energy and water that is actually lost can be replenished. Continuous operation is possible with just one step, saving resources and energy. Such an effect is possible because the target is ice, and cannot be achieved with something that vaporizes like dry ice. Also, pollution can be naturally prevented compared to using sand or the like. FIG. 2 shows an embodiment of the ice blasting device of the present invention using the ice slurry manufacturing device described above. As shown in the figure, 21 is a cold water tank, which is a modified form of the cold water tank 1 described above, but is essentially the same. It is.

That is, the inverted funnel-shaped internal shape consisting of the middle chamber 22 and the guide passage 23 is used as the external shape of the cold water tank 21, and the outside of the cold water tank 1 described above is removed to simplify the design. However, in order to separate the make-up water supply port and the ice slurry take-out port at the top, the guide path 23 is divided into two by a partition wall, and the guide path 2
One end extending on the vertical line of 3 is defined as an outlet path 24, and the other end extending from the vertically angled bridge and branching off is defined as a replenishment channel 25. 26 is a pressure feeding device such as an air compressor or a high pressure pump, and is provided to discharge compressed air or high pressure water to a pressure feeding pipe 27 extending from this device.

A take-out pipe 28 extending from the take-out passage 24 of the ice slurry manufacturing device is connected to the middle of the pressure feed pipe 27, so that the taken-out ice slurry is made to join the pressure feed pipe 27. 29
An ice slurry injection nozzle is attached to the tip of the pressure feed pipe 27, and is provided to spray the knitted material 301 such as a steel plate at high pressure.

Reference numeral 31 denotes a collection tank, which is provided to collect used ice and water that have been projected onto the object to be polished 30 and fallen and scattered as cold water.

Reference numeral 32 denotes a water treatment device which pumps up the collected cold water with a cold water pump 33 and passes it through a washing filter, and is provided as a known treatment device including a filter, a cyclone, etc. as an element.

The cold water after such treatment is returned to the supply path 25 of the ice slurry manufacturing apparatus by a pump 34. In addition, the recovery tank 31
The collected water and ice are separated using a sieve or the like, and the water is returned to the raw water tank, that is, the make-up water tank 3, via the water treatment device 32, and the ice is cleaned of waste by a known cleaning method and then sent to the make-up path of the ice slurry manufacturing device. 25 or the extraction path 24 for direct collection. Next, the operation of this embodiment of the ice blasting device will be explained.

In FIG. 2, the ice slurry 35 obtained from the ice slurry manufacturing device is automatically sucked into the take-out pipe 28 by operation of the pressure feeding device 26, and flows into the pressure feeding pipe 27 where it merges with compressed air or high pressure water. , is injected from the injection nozzle 29 at high pressure. In this jetting, the ice grains have hardness and weight, so when they collide with the object to be polished 30, they peel off dirt due to the friction and impact effect, and the water has a cleaning effect that washes away these dirt. Demonstrate a synergistic effect. Moreover, all ice grains have a uniform particle size, so they are not inferior to sand or steel grains. The used water and ice are collected as they are along with the waste, cleaned by the water treatment device 32, and then returned to the ice slurry device. This feedback allows the ice blasting device to operate as a nearly closed cycle system. In other words, with the exception of cold heat (liquid nitrogen), which must be constantly supplied, almost complete recovery of water and ice is possible even in the grinding section, which is the only barrier in this device. This is because the removed cold heat is replenished by the cooling device 5 (see FIG. 1) of the automatic cold water supply element in the system and by liquid nitrogen. This is the same whether an air compressor or a high-pressure pump is used as the pressure feeding device 26, and both can form an open cycle. Therefore, there is no possibility of foreign matter entering the system from outside the system, and only dirt on the object to be polished is generated by the cleaning staff, and only a small amount of waste is discharged, making it ideal for nuclear power plants, special chemical plants, etc. It can be suitably used for cleaning equipment where dust and foreign matter should not be mixed in.

In addition, unlike sandblasting, which generates almost no dust, it can be widely applied to cleaning street structures and walls of densely packed pillars, and there is no need to place restrictions on where it can be applied. Furthermore, since ice and cold water are reused after use, replenishment from outside the system is only necessary to supply cold heat and water equivalent to the amount consumed within the system, and the amount is extremely small, reducing the amount of waste. At the same time, it is possible to save resources.

Additionally, the device can be configured as an independent device with power, water, and liquid cryogen supplies that are not bulky, complicated, or difficult to obtain, and are generally easily procured anywhere. Since it can be used anywhere, it can be used in any place, and since it can be operated continuously, it can be used as a system and has a wide range of applications.

FIG. 3 shows an embodiment of the pipe cleaning device of the present invention using the ice slurry manufacturing device described above. As shown in the figure, 41 is a cold water tank, which is similar to the cold water tank 21 shown in FIG. It's the same thing.

Reference numeral 42 designates a pump, which connects a take-out pipe 44 extending from a take-out device 43 to its inlet, and supplies ice particles or ice slurry to the pipe to be cleaned 45 directly or via a bypass pipe from its discharge port.
It is set up to be sent to.

A filth removal tank 46 is provided to collect ice and water discharged from the pipe to be cleaned 45 either directly or via a bypass pipe, and filth is removed here to purify the ice slurry.

A pump 47 is provided to return the ice slurry purified in the dirt removal tank 46 to the supply path 46 of the ice slurry manufacturing apparatus.

Incidentally, in this apparatus, elements for automatically supplying cold water from the ice slurry manufacturing apparatus, that is, the make-up water tank 3, the pump 4, and the cooling device 5 are removed. However, to explain the effect of the above configuration,
The ice grains or ice slurry that has passed through the take-out pipe 44 is passed through the pump 42
The pipe 45 to be cleaned is directly cleaned from the outlet port without contacting the outside air.
sent to.

As a result of this delivery, the ice or ice slurry flows in the pipe 45 to be cleaned as a turbulent flow at a high flow rate, and as a result, the impact effect of the ice particles, the cleaning effect of the water, and the synergistic effect of the two are exerted, and the inner wall of the pipe is Perform cleaning. The ice slurry mixed with dirt discharged from the pipe to be cleaned 45 is also taken out without coming into contact with the outside air and collected in the dirt removal tank 46. The purified ice slurry is then returned to the supply path 48 of the ice slurry production device and used for ice production again. This process shows that the ice particles or ice slurry always pass through the conduit or similar sealed channel without ever being exposed to the outside air. This means that if the pipes etc. are designed so that no heat can pass in or out through heat exchange, or if there is heat loss, unless it is actively done, the loss of cold heat will be quite small. And it means that. Therefore, it is only necessary to replenish cold heat corresponding to this loss using the liquid nitrogen tank 7, and this replenishment forms the only open loop of this system. This is because the amount of ice grains or ice slurry taken out from the ice slurry manufacturing device is the same as the amount of ice slurry collected and returned, and the water and cold heat (water) in the cold water tank 41 are not lost during the process. This is because there is no need to supply it from outside the system.
In other words, this device can be said to constitute a completely open cycle system, except for the replenishment of cold energy (liquid nitrogen). In addition, in order to smooth the initial operation or to make the particle size uniform, a cold water tank 4 is installed.
It is desirable that the water in step 1 is not room temperature water but cold water of 0 to 4 degrees Celsius, but since the water temperature in the cold water tank 41 will be sufficiently cooled by the circulation action of the system itself and settle to 0 to 4 degrees Celsius, from the beginning. Room temperature water may be used, and in this case, the cooler 5 is not required.

Therefore, high-speed circulation of ice slurry is possible, and a continuous cycle can be established simply by replenishing cold energy (liquid nitrogen).
On the other hand, not only is there no contamination of foreign substances from outside the system, but also the filth generated within the system is the same as the one that existed in the original pot system, so even if the filth cannot be completely removed in the filth removal tank 46,
Or, even if the water treatment is incomplete, the system will not be affected and no inconvenience will occur. In addition, since this device turns water into ice particles, if the system in which the pipe 45 to be cleaned is a component uses water, the water can be used as is to make ice slurry. Furthermore, once the ice has melted, the equipment for the piping system to be cleaned can be put into operation again without having to dispose of it.

Furthermore, even if it is desired to locally clean the plant piping, it can be easily cleaned by operating the valve and using the bypass piping, and since there is no contamination of foreign matter, there is no need for flushing, and work efficiency can be improved.

In summary, the present invention exhibits the following excellent effects.

'1} Ice grains and ice slurry can be continuously produced with a simple structure, and uniform ice grains or ice slurry with uniform particle size can be extracted economically.

{2'Cold heat and water resources can be recovered and reused, and the amount of waste generated is extremely small, so there is no waste from dust pollution, and there are no restrictions on construction locations.

{3' It is possible to continuously produce ice or ice slurry only by replenishing cold heat, and there is no need to replenish water, which saves resources, and it is a completely closed cycle system that does not allow foreign matter to enter from the outside. This makes it particularly useful for cleaning piping that contains radioactive materials, such as those in nuclear power plants, where it is difficult to use chemical cleaning chemicals, and can help prevent pollution.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view schematically showing a preferred embodiment of the ice slurry production apparatus according to the present invention, and FIG. 2 is a sectional view schematically showing a preferred embodiment of the ice blasting apparatus according to the present invention. FIG. 3 is a sectional view schematically showing a preferred embodiment of the pipe cleaning device according to the present invention.

In the figure, 1, 21, 41 are cold water tanks, 6 is a small chamber, 8 is a rapid barrel throwing means, 9 is cold water, 10 is a cold water throwing means 12, 13 is a guide passage, 13 is ice grains, and 26 is a pressure feeding device , 30 is a bridge object to be polished, 31 is a collection tank, 32 is a water treatment device, 42 is a pump, 4
5 is a pipe to be cleaned, and 46 is a filth removal tank.

Multi-7 diagrams Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. A cold water tank to which cold water is automatically supplied; a small chamber provided in the lower part of the tank so as to communicate with the cold water tank and into which a liquid cryogen such as liquid nitrogen is continuously injected; a rapid stirring means for uniformly dispersing a liquid cryogen in cold water to form ice particles; a slow stirring means provided in the middle of the cold water tank for promoting the growth of ice particles obtained from the small chamber; and a slow stirring means provided in the upper part of the cold water tank. 1. An ice slurry manufacturing apparatus, comprising: a guide path for separating the grown ice particles from the cold water and guiding the grown ice particles upward, and configured such that ice particles or ice slurry can be continuously taken out from the guide path. 2. A cold water tank to which cold water is automatically supplied, a small chamber provided below this so as to communicate with the cold water tank and into which a liquid cryogen such as liquid nitrogen is continuously injected, and a small chamber provided in this small chamber to uniformly distribute the liquid cryogen into the cold water. a rapid stirring means for dispersing and forming ice particles; a slow stirring means provided in the middle of the cold water tank to promote the growth of ice particles obtained from the small chamber; and a slow stirring means provided in the upper part of the cold water tank to separate it from the cold water. A guide passage that guides the grown ice grains upward, a pumping device that pumps the ice grains or ice slurry taken out from the guide passage, and an injection nozzle that sprays the pumped ice grains or ice slurry onto the object to be polished. and a collection tank for collecting the injected ice slurry, and a water treatment device for purifying the ice slurry in the collection tank, and configured to return the purified ice slurry to the cold water tank. Features an ice blast device. 3. A cold water tank for storing cold water, a small chamber provided at the bottom of this tank in communication with the cold water tank and into which a liquid cryogen such as liquid nitrogen is continuously injected, and a small chamber provided in this small chamber to uniformly disperse the liquid cryogen in the cold water to form ice. rapid stirring means for forming particles; slow stirring means provided in the middle of the cold water tank to promote the growth of ice particles obtained from the small chamber; and ice grown separated from the cold water provided in the upper part of the cold water tank. It is equipped with a guide passage that guides the ice particles upward, a pump that sends the ice particles or ice slurry taken out from the guide passage to the piping to be cleaned, and a waste removal tank that collects the ice slurry discharged from the piping to be cleaned. A pipe cleaning device characterized in that it is configured to return purified ice slurry to the cold water tank.