JPS6240144B2 - - Google Patents

Description

Detailed Description of the Invention Technical Field The present invention is a method for removing dirt, oil, rust, etc. attached to an object to be processed, such as machine parts, by spraying a liquid mixture containing abrasive grains, which is an abrasive, onto the object to be processed, such as mechanical parts. The present invention relates to a wet blasting device that performs grinding of surface-fixed substances, surface hardening, etc.

BACKGROUND ART Conventionally, this type of wet blasting apparatus has a structure in which a liquid mixture of water and an abrasive material such as alumina or glass beads is injected from a nozzle together with compressed air. By spraying the mixed liquid, dirt and other adhered substances adhering to the surface and gaps of the object to be treated are removed, and the surface is finished.

However, in the above-mentioned conventional wet blasting equipment, since water is used as the injection liquid, a sufficient cleaning and degreasing effect cannot be obtained, it takes time to process the workpiece, and the workpiece after grinding is It takes time to dry. In addition, since it contains water, it is difficult to collect used abrasive materials, and it is troublesome to dispose of dirt made up of adhered substances removed by grinding.

Purpose of the Invention The present invention was made in view of the problems of conventional wet blasting equipment as described above.
The purpose is to provide a wet blasting device that can provide extremely good cleaning and degreasing effects, can perform rapid processing, and can dry objects to be treated in a short time by using a low boiling point solvent. There is a particular thing.

Another object of the present invention is to provide a wet blasting apparatus that can shorten the drying time of cleaning dirt and abrasive material by using a low boiling point solvent.

Embodiment Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the drawings.

In a diagram showing the basic configuration of a wet blasting apparatus according to an embodiment of the present invention, reference number 1 indicates a workpiece (not shown) such as a contaminated tool in a nuclear power plant.
It is a processing container that performs processing, and has a highly airtight structure. In a tank 3 provided at the bottom of the processing container 1, a mixed liquid 2 made by mixing Freon, which is a low boiling point solvent, and an abrasive material such as alumina or glass beads is stored. 4 is an injection nozzle. The mixed liquid 2 in the tank 3 is sent by the pump 6 through a line 30 and a valve V8, and is ejected from the injection nozzle 4 onto the object to be processed disposed in the processing container 1 together with fluorocarbon gas, which will be described later.

The spouted mixed liquid 2 returns to the tank 3 together with the solid matter removed from the object to be processed, but some of the fluorocarbon liquid is vaporized and flows from the exhaust pipe at the top of the processing container 1 to the line 31 where the filter 7 and valve V2 are located. and is sent to the compressor 8. The filter 7 is for removing particulates such as abrasives contained in the fluorocarbon gas. The fluorocarbon gas sent to the compressor 8 via the line 31 is compressed and becomes a high-pressure gas, which passes through the oil separator 9 and the dryer 10, passes through the line 32, and the valve V1, and is sucked up by the pump 6 as a liquid mixture. It is injected as a pressure source of 2. During operation, a continuous equilibrium state is maintained by the above circulation system.
Here, since the lubricating oil in the compressor 8 mixes with the freon gas, the oil separator 9 removes this and returns it to the compressor 8 via lines 33 and 34. This reduces lubricant consumption. The dryer 10 removes moisture contained in the air since residual air in the processing container 1 mixes with the fluorocarbon gas.

Note that a part of the mixed liquid 2 that is circulated at high speed through the line 30, the injection nozzle 4, and the tank 3 by the pump 6 described above is diverted to the stirring line 35 and directly returned to the tank 3. By this return from the stirring line 35, the mixed liquid 2 in the tank 3 is stirred, the mixed state of the Freon liquid and the abrasive particles is maintained uniformly, and only the abrasive is prevented from settling.

Now, since the mixed liquid 2 and the fluorocarbon gas injected from the injection nozzle 4 are suddenly released from the high pressure state, the self-cooling action of the fluorocarbon gas acts and the temperature decreases. On the other hand, the temperature of the mixed liquid 2 that is circulated at high speed by the pump 6 increases due to the heat generated by the above-mentioned stirring, but in order to balance this temperature drop, the temperature in the processing container 1 and the mixed liquid 2 in the tank 3 increase. The temperature is kept below the boiling point of Freon at atmospheric pressure. Therefore, even if the opening/closing door is opened when the object to be processed is taken into or taken out of the processing container 1, consumption of fluorocarbon by vapor can be suppressed to a minimum. In addition, by increasing the amount of fluorocarbon gas suctioned by the compressor 8 than the amount ejected from the nozzle 4 to maintain the inside of the processing container at a negative pressure compared to the outside air at all times during operation, gas leakage is prevented and contaminants are leaked to the outside. is prevented.

A part of the high-pressure fluorocarbon gas discharged from the compressor 8 is divided into lines 36 and sent to the liquefier 12 via the pressure valve 11. The pressure valve 11 is used to adjust suction and discharge by the compressor 8, and is used to drain excess gas to the liquefier 12 so that the flow of fluorocarbon gas from the processing container 1 to the processing container 1 via the lines 31 and 32 maintains an equilibrium state. lead to. The liquefier 12 can liquefy the sent Freon gas by the cooler 12-1 and separate and remove residual air mixed in the Freon gas from the exhaust pipe 12-1.
Furthermore, the liquefied Freon is transferred from the liquefier 12 to the line 3.
7. It is sent to the distiller 13 via valve V3. The freon sent to the distiller 13 is recondensed by steam heated by the heater 14 and liquefied by the cooler 13-1 from the refrigerator 19, and sent to the next liquid storage tank 16 via the line 38. . Note that 15 is a water separator, which removes residual moisture in the distiller 13. In addition, the oil separated from the fluorocarbons by the distillation and accumulated at the bottom of the distiller 13 (the lubricating oil of the compressor 8 that could not be removed by the oil separator 9) is transferred to the compressor 8 via a line 39. be returned.

The liquid reservoir 16 is equipped with a cooler 16-1 including a refrigerator 19 for storing distilled clean fluorocarbon. It also includes a liquid supply port 17 for supplying new liquid. A liquid supply pump 18 connected to the liquid storage device 16 supplies the stored fluorocarbon to the tank 3 in the processing container 1 through a line 40, and also performs the final cleaning of the processed material after the treatment by the injection nozzle 4. Refill cleaning nozzle 5
send to The fluorocarbon liquid is supplied to the cleaning nozzle 5 via a line 41 that branches off from a line 40. Further, the supply to the tank 3 and the cleaning nozzle 5 is performed simultaneously or only to one side as necessary by opening and closing the valves 10 and 11, and the supply amount is adjusted. A liquid level gauge 20 attached to the tank 3 detects the decrease and operates a liquid supply pump to keep the liquid level constant so as to maintain an appropriate liquid level at all times.

Next, as described above, a part of the mixed liquid 2 sucked up by the pump 6 is sent to the two cyclones 21 through the line 42 and the valve V7. Fine abrasives crushed by the cyclone 21 for grinding by jetting from the jetting nozzle 4 contained in the liquid mixture 2 and surface-fixed matter (cleaning dirt) removed from the object to be processed.
is separated and removed and dropped into a sludge tank 22 connected to the bottom. With this system, tank 3
It is possible to prevent fine dust such as abrasive materials and cleaning dirt from accumulating inside the body. The remaining fluorocarbons after separation and removal by the cyclone 21 are recovered into the tank 3 via the line 43 and the valve V6. Furthermore, the fluorocarbon liquid mixed into the tank 22 together with the cleaning waste is transferred to the tank 3 via the line 49 and the valve V9.
Return to

23 is a wet cyclone for recovering the abrasive material in the tank 3 to the outside. The wet cyclone 23 is connected to the tank 3 via a line 44 connected at A and A' in the figure.
The abrasive material is separated from the mixed liquid 2 sent from inside.
The separated abrasive material is stored in a recovery tank 24. Further, the remaining fluorocarbon is returned to the tank 3 via the line 45.

Note that the cleaning filth and abrasive material stored in the sludge tank 22 and recovery tank 24 contain fluorocarbons, but in this case, by operating valves V5, V9, valve V13, etc., the line 46 of the sludge tank 22 and the recovery If the line 47 of the tank 24 (connected at B and B') is communicated with the lines 31 and 48 on the suction side of the compressor 8,
The fluorocarbons in the sludge tank 22 and the recovery tank 24 are vaporized and recovered by the suction of the compressor 8, and the fluorocarbons are recovered in the tank 2.
Cleaning dirt and abrasive material remaining in the cleaning parts 2 and 24 become dry in a short period of time. This makes it extremely easy to dispose of the washed dirt and recovered abrasive material. Also,
Tank 3 after collecting the abrasive material through the above operations
The fluorocarbons in the tank are removed by operating only the compressor 8 with valve V2 open and valve V1 closed.
6 can be vaporized and recovered. In this case, heating is performed by the heater 25 in order to prevent a temperature drop due to heat of vaporization and to promote vaporization.

Further, 50 is a suction line for sucking up the mixed liquid 2 in the tank 3 and ejecting it from the injection nozzle 4 by using the bench-lily effect caused by the airflow of high-pressure freon gas instead of the pump 6 described above. When sucking up the mixed liquid 2 through the suction line 50, the valve V8 is closed and the valve V12 is opened. When high-pressure fluorocarbon gas is fed from the line 32 through the valve V1, it becomes a negative pressure state at the outlet of the injection nozzle 4, so it is transferred to the tank 3 due to the vent lily effect.
The mixed liquid 2 inside is sucked up to the injection nozzle 4 via the suction line 50, and is injected from the injection nozzle 4 together with the fluorocarbon gas. When the mixed liquid 2 is sucked up using this bench-lily effect, the cleaning and grinding effects are lowered because the suction force is weaker and the injection flow rate is lower than when the pump 6 is used to suck up the mixed liquid 2. In minor cases, sufficient effects can be obtained. Further, compared to the case where the pump 6 is used, there is an advantage that the power consumption is lower and the device can be simplified.

In the above, since the pump 6 and the suction line 50 are installed together, by adjusting the valves V8 and V12, either suction by the pump 6 or suction by the line 50 can be selected as appropriate depending on the degree of contamination of the object to be treated. This makes cleaning and grinding more efficient and extremely convenient. Note that the pump 6 and the suction line 50 do not necessarily need to be installed together, and only one of the suction means may be provided depending on the application of the device.

The wet blasting device according to an embodiment of the present invention is constructed and operates as described above, and uses Freon, which is a low boiling point solvent that is easily lost due to vaporization but has excellent cleaning and degreasing effects, to minimize loss. It is intended to be used in a controlled and efficient manner.

According to this device, good cleaning of Freon,
Due to the degreasing effect, it is possible to quickly process the object to be processed, and the fluorocarbon can be circulated and used without loss. Further, due to the low boiling point of fluorocarbons, the object to be treated can be dried in a short time, and cleaning dirt and abrasive material can be dried and recovered in a short time. Furthermore, since the vaporized fluorocarbon gas is pressurized and used for injection, it is possible to
There is no need to provide a separate compressed air supply device unlike a wet blasting device that injects the air with compressed air.

Further, in the above embodiment, a case was shown in which a mixture 2 of a low-boiling point solvent, fluorocarbon, and an abrasive was used as the cleaning liquid, but fluorocarbon alone may be used as the cleaning liquid without mixing an abrasive. If the amount of dirt, oil, etc. adhering to the object to be treated is light, a sufficient cleaning effect can be obtained just by spraying Freon. In this case, the cost required for cleaning will be reduced by the amount of the abrasive material, and the entire apparatus will be simplified because the wet cyclone 23 and recovery tank 24 for separating and recovering the used abrasive material are no longer required. Further, although an example using fluorocarbon as a low-boiling point solvent has been shown, the same effect as the above-mentioned fluorocarbon solution can be obtained by using other low-boiling point solvents such as trichlorethylene and perchlorethylene. However, it is non-flammable, non-toxic,
Freon liquid is probably the best because it is odorless.

Further, in the above embodiment, the distillation system consisting of the distiller 13, the heater 14, the liquid reservoir 16, the refrigerator 19, etc. is built into the apparatus, but if the same effect as described above can be obtained. It is okay to set it up separately.

Effects According to the present invention, since a low boiling point solvent with excellent cleaning and degreasing effects is used, the cleaning and grinding of the workpiece can be performed effectively and quickly. Since the low boiling point solvent easily vaporizes, the object to be treated can be dried in a short time. In addition, the time taken to dry the objects to be treated, the cleaning dirt, and the abrasive material is shortened, making recovery processing easier.

In addition, it is possible to recover the highly volatile low boiling point solvent by the recovery means and reuse the recovered gas, thereby enabling efficient operation.

The wet blasting apparatus according to the present invention is most effective for decontamination work performed during the disposal of radioactively contaminated materials in nuclear facilities. In this application, it is impossible to scatter contaminants, so
It is important to have a completely closed system. It is also equipped with a cyclone device that separates and removes dirt and abrasive particles after cleaning.
The ability to separate and collect containers and collect contaminated residue in a dry state is extremely useful in terms of minimizing waste and facilitating recovery.

[Brief explanation of the drawing]

The figure is a basic configuration diagram of a wet blasting device according to an embodiment of the present invention. Here, 1... processing container, 2... mixed liquid, 3... tank, 4... injection nozzle, 6... pump, 8... compressor,
12... liquefier, 13 distiller, 16... liquid reservoir, 21
...cyclone, 22...sludge tank, 23...wet cyclone, 24...recovery tank, 50...suction line.

Claims (1)

[Scope of Claims] 1. In a wet blasting device that cleans or grinds the surface of a workpiece by spraying a liquid onto the workpiece, a low boiling point solvent is used as the liquid, and the low boiling point solvent is stored in a closed tank. A wet blasting apparatus comprising: an injection means for injecting the low boiling point solvent; and a recovery means for recovering the low boiling point solvent injected in the closed tank. 2. The wet blasting device according to claim 1, wherein the low boiling point solvent is fluorocarbon.