JP7093112B2 - Cleaning liquid regeneration device, cleaning device and cleaning liquid regeneration method - Google Patents

Description

The present invention relates to a cleaning liquid regenerating device for regenerating a cleaning liquid of a processed product such as various machine parts, a cleaning device using the cleaning liquid, and a cleaning liquid regenerating method.

Since various processing oils are used for processing machine parts and the like, it is necessary to wash the processed products to remove the processing oils. As the cleaning liquid conventionally used, organic solvents such as alcohol-based and hydrocarbon-based are used.

On the other hand, recently, metal processing using water-soluble processing oil has also been widely performed. Therefore, an aqueous cleaning solution is used to remove so-called water-soluble stains adhering to the processed product. When a non-flammable cleaning liquid containing an organic solvent component such as glycol ethers and water is used as the aqueous cleaning liquid, there is an advantage that the safety is high.

It is preferable to regenerate the aqueous cleaning solution after use and use it repeatedly from the viewpoint of environment and resource saving. In Patent Document 1, after distilling the used cleaning liquid, the organic solvent component in the cleaning liquid is condensed at a cooling temperature higher than the boiling point of water by the first-stage cooling means, and the organic solvent component in the cleaning liquid is condensed by the second-stage cooling means, which is higher than the boiling point of water. A device and a method for condensing water vapor at a low cooling temperature to regenerate the cleaning liquid solvent are described.

By the way, the cleaning device is not continuously in the operating state, but is repeatedly started and stopped. Therefore, while the washing operation is stopped, the regenerating device also stops the operation, but when the operation is restarted, it is necessary to raise the temperature inside the distiller again to stabilize the distillation temperature. This makes it possible to stabilize the composition of the cleaning liquid. However, when the regenerating device is also stopped every time the cleaning device is stopped, there is a problem that it takes time and cost to restart and the efficiency is poor.

Japanese Unexamined Patent Publication No. 2009-172468

An object of the present invention is to provide a cleaning liquid regenerating device, a cleaning device, and a cleaning liquid regenerating method capable of efficiently performing a cleaning operation with a regenerated cleaning liquid.

The cleaning liquid regenerating device of the present invention for solving the above problems is a first recovery tank for collecting used cleaning liquid and a distiller connected to the first recovery tank to send the used cleaning liquid from the first recovery tank. A first condenser that cools the gas distilled from the distiller and condenses the organic solvent component contained in the cleaning liquid, and a second recovery tank that recovers the organic solvent component condensed by the first condenser. The second recovery tank is characterized by having a means for sending the organic solvent component to the first recovery tank during standby for cleaning operation and a means for sending the organic solvent component to the cleaning unit during cleaning operation. ..
The cleaning device of the present invention includes the above-mentioned cleaning liquid regenerating device.
The cleaning liquid regeneration method of the present invention includes a step of collecting used cleaning liquid in a first recovery tank, a step of sending used cleaning liquid from the first recovery tank to a distiller for distillation, and a step of distilling from the distiller. The cleaning operation standby includes a step of sending the gas to the first condenser to condense the organic solvent component contained in the cleaning liquid and a step of recovering the organic solvent component condensed in the first condenser in the second recovery tank. Occasionally, the organic solvent component recovered in the second recovery tank is sent to the first recovery tank, and during the cleaning operation, the organic solvent component is sent from the second recovery tank to the cleaning unit.

According to the present invention, the distillation temperature is stabilized because the distillation and regeneration of the cleaning liquid is performed not only during the cleaning operation but also during the standby operation of the cleaning operation. Further, the organic solvent component condensed by the first condenser has a relatively high temperature. Therefore, when the organic solvent component is sent to the cleaning unit and used for the cleaning operation, the reheating step of the organic solvent component is simplified, the efficiency of the cleaning operation is improved, and energy is saved.

It is a block diagram which shows the cleaning apparatus provided with the cleaning liquid regeneration apparatus which concerns on 1st Embodiment of this invention.

A cleaning device according to an embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, the cleaning device 100 includes a first cleaning tank 1, a second cleaning tank 2, and a drying tank 3. An ultrasonic transducer (US) 6 is installed in the first cleaning tank 1 and the second cleaning tank 2, and the object to be cleaned (hereinafter, may be referred to as a work) 4 such as mechanical parts is the first. The cleaning tank 1 and the second cleaning tank 2 are ultrasonically cleaned in this order, rinsed in the drying tank 3 (steam cleaning), and then dried.

The cleaning liquid is sent in the order of the second cleaning tank 2 and the first cleaning tank 1, contrary to the work 4, and the cleaning liquid discharged from the first cleaning tank 1 is sent to the first distiller 5 to distill the cleaning liquid. Playback takes place. The cleaning liquid from which the dirt components have been separated by the first distiller 5 is circulated in the order of the second cleaning tank 2 and the first cleaning tank 1.

The cleaning liquid used is preferably a non-flammable cleaning liquid containing an organic solvent component. Examples of the non-flammable organic solvent component include organic solvent components including glycol ethers. The cleaning liquid used for cleaning in the first cleaning tank 1 and the second cleaning tank 2 may contain an organic solvent component and water. The content of water is about 5 to 40% by volume, preferably about 10 to 30% by volume, based on the total amount of the cleaning liquid.

Glycol ethers have a boiling point of 120 to 275 ° C., preferably 135 to 230 ° C. under normal pressure. As a result, the organic solvent component can be easily separated from water, and the cleaning liquid is excellent in drying property. That is, if the boiling point of the glycol ethers is less than 120 ° C., it becomes difficult to separate from water during distillation regeneration. Further, when the boiling point of the glycol ethers exceeds 275 ° C., it becomes difficult to dry the work in the drying step.
As described above, the glycol ethers have a boiling point difference with water, so that they can be easily separated from water, and therefore the distillation amount, temperature, and cleaning liquid composition can be stabilized in a short time.

Examples of the glycol ethers that can be used include one or more selected from propylene glycol and ethylene glycol.

Specific examples of propylene glycols include propylene glycol methyl ether, dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether, propylene glycol n-butyl ether, and dipropylene glycol. Examples thereof include n-butyl ether, tripropylene glycol n-butyl ether, propylene glycol methyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol diacetate, and propylene glycol phenyl ether.

Specific examples of ethylene glycols include diethylene glycol methyl ether, triethylene glycol methyl ether, diethylene glycol ethyl ether, triethylene glycol ethyl ether, ethylene glycol n-propyl ether, ethylene glycol n-butyl ether, ethylene glycol tert-butyl ether, and diethylene glycol n. -Butyl ether, triethylene glycol n-butyl ether, ethylene glycol hexyl ether, diethylene glycol hexyl ether, ethylene glycol n-butyl ether acetate, diethylene glycol n-butyl ether acetate, ethylene glycol phenyl ether, ethylene glycol ethyl ether, diethylene glycol monoethyl ether acetate, ethylene glycol Examples thereof include ethyl ether acetate, ethylene glycol methyl ether, 3-methoxy-3-methyl-1-butanol and the like.

Further, propylene glycol and ethylene glycol have a flash point of 30 ° C. or higher, preferably 40 ° C. or higher. Glycol ethers with such a low flash point can be used because they mix with water. This gives a non-flammable cleaning solution. The flash point is measured by a tag sealed flash point measuring instrument (JIS K 2265-1).

In the present invention, it is particularly preferable to use hydrophilic glycol ethers that are effective against water-soluble stains. Examples of such hydrophilic glycol ethers include propylene glycols such as propylene glycol methyl ether, dipropylene glycol methyl ether, propylene glycol n-propyl ether and tripropylene glycol methyl ether; and ethylene glycol n-propyl ether. Ethylene glycol n-butyl ether, ethylene glycol tert-butyl ether, diethylene glycol methyl ether, triethylene glycol methyl ether, diethylene glycol ethyl ether, triethylene glycol ethyl ether, diethylene glycol n-butyl ether, ethylene glycol ethyl ether, diethylene glycol monoethyl ether acetate, ethylene glycol Examples thereof include ethylene glycols such as ethyl ether acetate, ethylene glycol methyl ether and 3-methoxy-3-methyl-1-butanol.

Further, a lipophilic solvent may be mixed to remove oil-soluble stains. The lipophilic solvent preferably has a boiling point under normal pressure higher than that of water, but is not particularly limited. Examples of the lipophilic solvent include hydrocarbon solvents such as hexane and naphtha, alcohol solvents such as methanol, ethanol and isopropanol, and the like, in addition to lipophilic glycol ethers. The amount of the lipophilic solvent added is preferably about 30 to 60% by volume with respect to the total amount of the cleaning liquid composition. Further, an antioxidant or the like can be appropriately added to the cleaning liquid composition.

Returning to FIG. 1, a part of the used cleaning liquid discharged from the first cleaning tank 1 is sent to the cleaning liquid regeneration device 101 by operating the three-way valve 7. The cleaning liquid regenerating device 101 includes a first recovery tank 8 that collects used cleaning liquid sent via the three-way valve 7, a second distiller 9 connected to the first recovery tank 8, and the second distiller 9. It includes a first condenser 10 to which the gas distilled from is sent, and a second condenser 11 connected to the downstream side of the first condenser 10. A vacuum pump 14 is connected to the second condenser 11. That is, the gas distilled from the second distiller 9 is sent to the vacuum pump 14 via the first condenser 10 and the second condenser 11. The vacuum pump 14 maintains the inside of the second distiller 9 in a vacuum atmosphere, and the cleaning liquid is distilled under reduced pressure. The vacuum pump 14 is also connected to the drying tank 3 to reduce the pressure inside the drying tank 3 to improve the efficiency of steam cleaning and drying.

The first condenser 10 condenses the gas (containing an organic solvent component and water) distilled from the second distiller 9 at a cooling temperature higher than the boiling point of water. Since the organic solvent component in the cleaning liquid is higher than the boiling point of water, the organic solvent component is mainly condensed.
Further, the second condenser 11 is set to a cooling temperature lower than the boiling point of water. As a result, water is condensed and removed from the gas discharged from the first condenser 10.

The second recovery tank 12 is housed in the upper part of the first recovery tank 8, and the organic solvent component condensed from the first condenser 10 is recovered in the second recovery tank 12. The second recovery tank 12 is located above the liquid level of the cleaning liquid contained in the first recovery tank 8. The second recovery tank 12 has an overflow portion formed by opening an upper portion or forming a hole or an opening (not shown) in the wall portion. Then, the organic solvent component overflowing from the second recovery tank 12 is housed in the first recovery tank 8. Further, a steam generator 16 is connected to the second recovery tank 12 via a feed pipe 17 having a pump 15. As a result, the organic solvent component recovered in the second recovery tank 12 is sent to the steam generator 16 to heat the organic solvent component to generate steam. The generated steam is sent to the drying tank 3 and used for steam cleaning of the work 4.

The second recovery tank 12 is housed in the first recovery tank 8, but is not limited to this. For example, the second recovery tank 12 may be installed above the first recovery tank 8 and overflow from the overflow portion described above. The organic solvent component may be allowed to fall into the first recovery tank 8. Alternatively, the second recovery tank 12 and the first recovery tank 8 are connected by a feed pipe without providing an overflow portion, and the organic solvent component is sent from the second recovery tank 12 to the first recovery tank 8. May be good. At that time, it is necessary to control the flow path by providing a switching valve (not shown) between the feed pipe 17 provided with the pump 15.

On the other hand, the third recovery tank 13 is connected to the second condenser 11, and the water cooled and condensed by the second condenser 11 is recovered. The recovered water may be discarded as it is, or it may be mixed with an organic solvent component and reused as a cleaning liquid.

Next, a cleaning method of the work 4 and a cleaning liquid regeneration method in the present embodiment will be described. The work 4 is sent in the order of the first cleaning tank 1 and the second cleaning tank 2 for ultrasonic cleaning, then sent to the drying tank 3, steam-cleaned (rinsed) with an organic solvent component, and then dried.

The cleaning liquid is sent in the order of the second cleaning tank 2 and the first cleaning tank 1, contrary to the work 4, and the cleaning liquid discharged from the first cleaning tank 1 is sent to the first distiller 5. In the first distiller 5, distillation regeneration is performed to separate dirt components such as oil from the used cleaning liquid. After the distillation regeneration, the cleaning liquid liquefied by the condenser (not shown) is sent again in the order of the second cleaning tank 2 and the first cleaning tank 1, and the work 4 is washed. The dirt component is discharged from the bottom of the first distiller 5.
The distillation temperature of the first distiller 5 is a temperature sufficiently high for the organic solvent constituting the cleaning liquid and water to volatilize and separate the contaminants. Distillation can be carried out under normal pressure or reduced pressure.

When the amount of cleaning liquid in the first recovery tank 8 becomes small in addition to the start of the cleaning operation, a part of the cleaning liquid discharged from the first and second cleaning tanks 1 and 2 or the first distiller 5 may be used. , The three-way valve 7 is operated and sent to the first recovery tank 8. The cleaning liquid recovered and stored in the first recovery tank 8 is sent to the second distiller 9, distilled in the same manner as in the first distiller 5, the organic solvent component in the cleaning liquid and water evaporate, and the second Distilled from the distiller 9. A sensor 18 for detecting the amount of liquid (for example, a float sensor for detecting the liquid level) is installed in the second distiller 9, and when the amount of liquid is low, the valve 19 opens and the cleaning liquid is second distilled. It is supplied into the vessel 9.

The distilled gas is sent by the vacuum pump 14 in the order of the first condenser 10 and the second condenser 11. In the first condenser 10, the organic solvent component in the cleaning liquid is condensed at a cooling temperature higher than the boiling point of water and separated from water vapor. The organic solvent component cooled and condensed in the first condenser 10 is recovered in the second recovery tank 12. On the other hand, the water vapor discharged from the first condenser 10 is cooled to below the boiling point of water in the second condenser 11, condenses the water, and is recovered in the third recovery tank 13.

At the start of the washing operation, as described above, the gas distilled from the second distiller 9 is sent to the first condenser 10, the organic solvent component is condensed, and the gas is recovered in the second recovery tank 12.
During the cleaning operation (that is, during steam cleaning), the pump 15 is driven to send the organic solvent component recovered in the second recovery tank 12 to the steam generator 16 through the feed pipe 17, and the steam generator is used. It is heated in 16 and the generated steam is sent to the drying tank 3 to perform steam cleaning of the work 4.
At that time, since the organic solvent component condensed in the first condenser 10 is cooled at a cooling temperature higher than the boiling point of water, it is relatively high in temperature, so that it is vaporized in the steam generator 16, that is, reheated. The process can be performed easily and in a short time, the efficiency of the cleaning operation is improved, and energy is saved.

On the other hand, while the washing operation is on standby, the pump 15 is stopped, but the operation of the second distiller 9 is continued. Therefore, in the second recovery tank 12, the organic solvent component cooled and condensed by the first condenser 10 is sent to the second recovery tank 12 in the same manner as in the washing operation, so that the organic contained in the second recovery tank 12 is stored. The amount of solvent component continues to increase. Finally, the organic solvent component overflows from the overflow portion, falls into the first recovery tank 8, and is sent to the second distiller 9 again for distillation. That is, the organic solvent component circulates in the order of the first recovery tank 8, the second distiller 9, the first condenser 10, and the second recovery tank 12.

In this way, since the distillation regeneration of the organic solvent component is continued in the second distiller 9 even while waiting for the washing operation, the distillation temperature of the second distiller 9 is stable and the amount of steam is also stable. The composition of the distillate steam from the distiller 9 is also stable. Therefore, the cleaning liquid can be regenerated and the cleaning operation can be efficiently performed.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various improvements and improvements can be made within the scope of the present invention. For example, in the above embodiment, the cleaning liquid regeneration device and the regeneration method using a non-flammable cleaning liquid containing an organic solvent component and water have been described, but a cleaning liquid containing only the organic solvent component may be used. In that case, the second condenser 11 and the third recovery tank 13 can be omitted. Further, instead of water, other components such as other organic solvent components may be used. At this time, it is desirable that the boiling points of the other components have a boiling point difference that can be separated from the organic solvent component.

1 1st washing tank 2 2nd washing tank 3 Drying tank 4 Work 5 1st distiller 6 Ultrasonic transducer 7 Three-way valve 8 1st recovery tank 9 2nd distiller 10 1st condenser 11 2nd condenser 12th 2 Recovery tank 13 3rd recovery tank 14 Vacuum pump 15 Pump 16 Steam generator 17 Supply pipe 18 Sensor 19 that detects the amount of liquid 19 Valve 100 Cleaning device 101 Cleaning liquid regeneration device

Claims (9)

The first recovery tank that collects the used cleaning liquid,
A distiller connected to the first recovery tank and to which the used cleaning liquid is sent from the first recovery tank.
A first condenser that cools the gas distilled from the distiller and condenses the organic solvent component contained in the cleaning liquid, and the first condenser.
A second recovery tank for recovering the organic solvent component condensed by the first condenser is provided.
The second recovery tank is characterized by having a means for sending the organic solvent component to the first recovery tank during the standby for the washing operation and a means for sending the organic solvent component to the washing unit during the washing operation. .. The second recovery tank is located above the liquid level of the cleaning liquid contained in the first recovery tank.
The means for sending the organic solvent component from the second recovery tank to the first recovery tank is an overflow portion provided in the second recovery tank.
The cleaning liquid regenerating device according to claim 1, wherein the means for sending the organic solvent component from the second recovery tank to the cleaning unit is a supply pipe connected to the second recovery tank. A claim that the cleaning unit includes a steam generating means for heating the organic solvent component sent from the second recovery tank and converting it into a gas, and a drying tank for steam cleaning and drying the object to be cleaned with the gas. Item 2. The cleaning liquid regenerating device according to Item 1 or 2. The cleaning liquid regeneration apparatus according to any one of claims 1 to 3, wherein a second condenser for condensing other components that do not condense at the cooling temperature in the first condenser is provided on the downstream side of the first condenser. The cleaning liquid regenerating device according to claim 4, wherein the other component is water, and the cooling temperature in the first condenser is higher than the boiling point of water. The cleaning liquid regenerating device according to any one of claims 1 to 5, wherein the cleaning liquid is a non-flammable cleaning liquid containing an organic solvent component and water. A cleaning device provided with the cleaning liquid regenerating device according to any one of claims 1 to 6. The process of collecting used cleaning liquid in the first recovery tank and
The process of sending the used cleaning liquid from the first recovery tank to the distiller and distilling it.
The step of sending the gas of the cleaning liquid distilled from the distiller to the first condenser to condense the organic solvent component contained in the cleaning liquid, and
The step of recovering the organic solvent component condensed in the first condenser in the second recovery tank is included.
During the washing operation standby, the organic solvent component recovered in the second recovery tank is sent to the first recovery tank, and during the washing operation, the organic solvent component is sent from the second recovery tank to the washing unit. Cleaning liquid regeneration method. During the washing operation standby, the organic solvent component recovered in the second recovery tank overflows from the second recovery tank and is sent to the first recovery tank.
The cleaning liquid regeneration method according to claim 8 , wherein during the cleaning operation, the organic solvent component is sent from the second recovery tank to the cleaning unit via a supply pipe.

Images