JPH0475694A - Method and device for distilling solvent in dry cleaning machine - Google Patents

Abstract

PURPOSE:To efficiently execute the distillation by the distillation quantity corresponding to the cooling capacity by decompressing a washing path at the time of a washing process, and also, controlling its decompression degree so as to maintain the decompression degree of a set specific range, and moreover, detecting directly the heating evaporation temperature of a distiller, and furthermore, controlling its vapor temperature so as to maintain the temperature of the set specific range. CONSTITUTION:When distillation is executed by driving a vacuum pump 50, the inside of a distillation path holds the decompression degree of a set range, for instance, 200Torr-210Torr. Simultaneously, the heating temperature of a vapor jacket 11a of a distiller holds a set range, for instance, at 150 deg.C-145 deg.C, and controls both of the distillation temperature and the decompression degree, therefore, distillation can be executed efficiently by the evaporation quantity corresponding to the cooling capacity of a condenser 12. Also, in accordance with a fluctuation of the decompression degree in the distillation path and a fluctuation of the cooling capacity of the capacity, etc., the distillation temperature is adjusted, and also, the decompression degree in the distillation path can be controlled. In such a way, while preventing bumping, distillation can be executed efficiently by the evaporation quantity corresponding to the cooling capacity of the condenser.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a dry cleaning machine that uses a solvent, and when repurifying the solvent contaminated by washing by distillation, distillation is performed while maintaining a stable state. The present invention relates to a distillation method and apparatus that can perform the following steps.

[Conventional technology]

A conventional dry cleaning machine will be described with reference to FIG.

In Figure 2, 1 is the main tank for solvent, and the solvent in the main tank is pumped through three-way valve 2 → pump 3 → filter 4 →
The liquid is circulated from automatic opening/closing valve 5 → washing tank 6 → automatic opening/closing valve 7 → button trap 8 → main tank 1, and the liquid level in that case is set by high liquid float 9 or low liquid float IO,
The inner shell of the cleaning tank 6 is rotated forward and backward at low speed to perform the cleaning process of the clothes in the cleaning tank, and the solvent contaminated by this cleaning process is sent to the distiller 11, and then the automatic opening/closing valve 60 is opened to remove clean oil. The cleaning solvent in the tank 14 is introduced into the cleaning tank 6 for rinsing, and the solvent used for the rinsing is returned to the main tank 1.

After the above-mentioned cleaning process is completed, the inner shell of the cleaning tank 6 is rotated at high speed to perform a liquid removal process, and thereafter.

The automatic opening/closing valves 15 and 16 are opened to communicate the drying system path consisting of the dust filter 17, fan 18, drying condenser 19, and heater 20 with the cleaning tank 6, and the fan 18, heater 20, and condenser 19 are driven to operate the heater. 20 is circulated between the washing tank 6 and the drying system to dry the clothes, and the vaporized solvent is condensed by the drying condenser 19, and the liquefied solvent is transferred to the recovery tank 21. One cycle of cleaning is completed by performing a drying/solvent recovery process to recover the solvent, and then a cooling process to gradually cool the inside of the system.

After the cleaning process is completed and before the slow cooling process is completed, the solvent contaminated by the cleaning process is sent to the distiller 11, and steam is introduced into the steam jacket lla at the bottom of the distiller 11, and the distiller A distillation process is performed in which the solvent in 11 is heated, the vaporized solvent is condensed in a condenser 12 for distillation, and the resulting clean solvent is stored in a clean oil tank 14 via a water separator 13. Note that the solvent stored in the clean oil tank 14 is used for rinsing during the next cleaning.

By the way, the general time required for the above series of dry cleaning processes is approximately 6 minutes for the cleaning process in which the solvent is circulated, approximately 4 minutes for the rinsing process, approximately 3 minutes for the dewatering process, and approximately 3 minutes for the drying process.・Approximately 15 minutes for solvent recovery process, approximately 3 minutes for slow cooling process,
A total of 31 minutes, therefore, the distillation step must be completed within 25 minutes.

By the way, the heat source in the distillation process is controlled by disposing a pressure reducing valve 23 in the steam supply pipe 22 leading to the steam jacket lla of the distiller 11, and manually adjusting the pressure reducing valve 23 to obtain steam at a desired temperature. That's what I was doing.

For example, distillation was carried out at 150° C. by operating the pressure reducing valve 23 and setting the vapor pressure to 4) cg/cJ.

It is also known to reduce the pressure in the distillation system such as a distiller, condenser, water separator, clean oil tank, etc. using a vacuum pump, and perform distillation at a predetermined degree of pressure reduction (Japanese Patent Application Laid-Open No. 61-170492, "Dry Oil Tank"). (Refer to "Reduced Pressure Distillation Method in Cleaning") [Problem to be Solved by the Invention] As mentioned above, the conventional distillation method in dry cleaning is controlled only by the steam pressure (heating temperature) or the degree of vacuum in the distillation system. As a result, the balance between the amount of evaporation on the distiller side and the cooling capacity on the condenser side is disrupted, causing dirty solvent in the distiller to blow up into the condenser side (this is called bumping), or cause the solvent to be used for the next cleaning within a predetermined period of time. There was a problem that it was not possible to distill the amount required.

In other words, the capacity of the condenser of a distillation device is determined by the minimum necessary capacity to distill the amount of solvent required for one dry cleaning in the try-cleaning device within a predetermined amount of time due to installation space issues and cost considerations. In addition, temperature control using a pressure reducing valve generally causes the distillation temperature to fluctuate as the primary pressure fluctuates, and the degree of pressure reduction within the distillation system also changes with the passage of time and changes in the distillation temperature. The amount of evaporation of the solvent changes depending on both the distillation temperature and the degree of vacuum in the distillation system. Therefore, controlling only the steam pressure (still) or the degree of vacuum in the system is not enough to control the distillation process. The main objective of reliably preventing bumping which tends to occur initially is the solid phase, and if conditions are set to ensure that bumping can be prevented, there is a problem in that an insufficient amount of distillation will occur.

The present invention improves the problems of the prior art as described above, reliably prevents bumping, and provides a distillation method and apparatus for a dry cleaning machine that can efficiently distill the amount of distillation commensurate with the cooling capacity of the condenser. The purpose is to provide.

[Means to solve the problem]

In order to achieve the above objects, the present invention reduces the pressure in the distillation system during the distillation process of try cleaning, and
The degree of reduced pressure is controlled to maintain the degree of reduced pressure within a specific set range, and the temperature of the heating steam of the distiller is directly detected, and the steam temperature is maintained within the set specific range. It is characterized by being controlled so that

Furthermore, the present invention provides a pressure reducing valve and an automatic opening/closing valve in the heated steam supply pipe of the distiller, and also provides a temperature detection sensor directly in the steam jacket, so that the detected value of the temperature detection sensor is within the set temperature range. When the upper limit is reached, an on-off valve provided in the steam supply pipe is automatically closed to temporarily interrupt the steam heating, and when the lower limit is reached, the on-off valve is automatically opened to continue the steam heating, In addition, a vacuum pump is connected to a part of the distillation system via an on-off valve, and a pressure detection sensor is installed to detect the pressure in the distillation system, and the detected value of the pressure detection sensor is within the set pressure reduction range. When the upper limit (vacuum of Keio University) is reached, the on-off valve leading to the vacuum pump is automatically closed and pressure reduction by the vacuum pump is temporarily interrupted, and when the lower limit (vacuum coal car) is reached, the on-off valve is opened and the vacuum pump is switched off. The invention is characterized by the provision of means for continuing the depressurization.

[Effect]

As described above, the present invention controls the distillation temperature according to the conditions of both the distillation temperature and the degree of vacuum in the distillation system, so it is possible to efficiently distill with an amount of evaporation commensurate with the cooling capacity of the condenser, and also to control the distillation temperature and the degree of vacuum in the distillation system. We have set upper and lower limits for the degree of pressure reduction in the distillation system, so if there is a change in temperature or degree of pressure reduction due to fluctuations in the secondary pressure caused by the pressure reducing valve, the distillation temperature will be adjusted accordingly. By adjusting the degree of vacuum and pressure reduction, smooth and efficient distillation can be carried out.

〔Example〕

Hereinafter, the present invention will be explained in detail based on FIG.

In Figure 1, 1 is the main tank, 2 is a three-way valve, 3 is a pump, 4 is a filter, 5 and 7 are automatic on-off valves, 6 is a washing tank, 8 is a button trap, 11 is a distiller, and 12 is for distillation. Condenser, 13 is a water separator, 14 is a clean oil tank,
15.16 is automatic opening/closing valve, 17 is dust filter, 18
is a fan, 19 is a drying capacitor, 20 is a heater, 2
Reference numeral 1 designates a solvent recovery tank during the drying process, which is configured to perform the washing process, rinsing, drying/solvent recovery process, and distillation process in the same manner as described with reference to FIG.

In the present invention, the steam jacket 11a of the distiller 11
A temperature detection sensor 100 is disposed inside, and a manual pressure reducing valve 23 and an automatic opening/closing valve 101 are disposed in the steam supply pipe 22 leading to the steam jacket lla of the distiller.
When it is detected that the steam temperature detected by 0 is at the upper limit of the set temperature range, for example 150°C, the automatic opening/closing valve 10
1 is closed, and when a lower limit, for example, 145° C. is detected, the control unit 102 automatically opens the automatic on-off valve 101.

Further, in the present invention, the distiller 11. Distillation condenser 12. Moisture separator 13. A vacuum pump 50 is connected to a part of the distillation system such as the clean oil tank 14, for example, through an automatic on-off valve 51, and the degree of vacuum (degree of reduced pressure) in the distillation system is measured using a pressure gauge. 53, and when the pressure change detected by the pressure gauge 53 reaches the upper limit of the set range, for example 560wnHg, the automatic opening/closing valve 51
When the lower limit is detected, for example, 550 mmHg, the automatic opening/closing valve 5 is closed.
1 is opened and the pressure inside the distillation system is reduced by the vacuum pump 50, which is automatically controlled by the control unit 54.

During distillation, the inside of the distillation system should be completely isolated from other routes. That is, 57 is a manual on-off valve provided in a pipe line that sends the clean solvent from which water has been separated by the water separator 13 to the clean oil tank 14, 58 is a manual on-off valve provided on the drain pipe of the water separator 13, and 52 is a clean solvent valve. Automatic opening/closing valve provided at the clean solvent inlet of the oil tank 14, 60 is the clean oil tank 14
An automatic opening/closing valve 62 is installed in the pipeline that transfers the clean solvent obtained from the drying/solvent recovery process to the clean oil tank 14. During distillation, the valve 62 60, 62° 58 is closed, valves 57, 51, and 52 are opened, and the vacuum pump 50 is driven to carry out distillation.

The solvent distillation apparatus for dry cleaning of the present invention has the configuration as described above, so that the valves 60, 62, and 58 are closed, the valves 57, 51, and 52 are opened, and the vacuum pump 5 is closed.
When distillation is performed by driving 0, the degree of vacuum in the distillation system is within a set range, for example, 560 m+Hg to 550 mu Hg.
At the same time, the heating temperature of the steam jacket 11a of the distiller is maintained within a set range, for example, 150°C to 145°C,
Since both the distillation temperature and the degree of reduced pressure are controlled in this way, efficient distillation can be performed with an amount of evaporation commensurate with the cooling capacity of the condenser 12.

In particular, in the present invention, the temperature control method of the distiller 11 is not simply by adjusting the pressure reducing valve 23 as in the past, but by detecting the actual temperature in the steam jacket lla, and detecting the upper limit of the setting range (for example, 150 ° C. ) is detected, the automatic on-off valve 101 is closed and heating is temporarily interrupted, and when the lower limit of the setting range (for example, 145° C.) is detected, the automatic on-off valve is opened and heating is resumed.

The distillation temperature is adjusted in response to fluctuations in the degree of reduced pressure in the distillation system and fluctuations in the cooling capacity of the condenser.

The degree of reduced pressure in the distillation system can also be controlled by setting an upper limit (for example, 560 mn).
When it is detected that the pressure has reached 145m+Hg, the automatic on-off valve 51 is closed and pressure reduction is interrupted, and when the lower limit (for example, 145m+Hg) is detected, the automatic on-off valve 51 is opened and pressure reduction is resumed, so it can cope with fluctuations in heating temperature, etc. By adjusting the degree of vacuum in the system, it is possible to prevent bumping, which tends to occur mainly at the beginning of the distillation process, and to perform distillation smoothly and efficiently.

〔Effect of the invention〕

As described above, according to the present invention, the conditions of both the distillation temperature and the degree of vacuum in the distillation system are controlled to be maintained within the set ranges, thereby preventing bumping that tends to occur at the beginning of the distillation process. This has the effect of efficiently distilling the amount of evaporation commensurate with the cooling capacity of the condenser.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a dry cleaning machine equipped with a distillation apparatus according to the present invention, and FIG. 2 is a block diagram of a conventional dry cleaning machine. 1... Main tank, 3... Pump, 4... Filter, 6... Cleaning tank, 5, 7, 15.16.51
．． 52.60.62 Automatic opening/closing valve, 8 Button trap, 11 Distiller, 11a Distiller steam jacket, 12 Distillation condenser, 13...
- Moisture separator, 14...Clean oil tank, 17...Dust filter, 18...Fan, 19...Dry condenser, 20...Heater, 22...Steam supply pipe, 23
...Pressure reducing valve, 100...Temperature detection sensor, 101.
...Automatic opening/closing valve, 102...Control unit, 50...Vacuum pump, 53...Pressure gauge, 54...Control unit 6 Patent applicant: Tokyo Washing Machine Manufacturing Co., Ltd. Patent attorney Akimoto True truth

Claims (1)

[Claims] 1. A washing process in which a solvent is supplied into a washing tank rotating at a low speed to wash the clothes in the washing tank, and after the washing process is completed, the washing tank is rotated at a high speed to remove liquid from the clothes. The deliquification process and the drying process, in which after the deliquification process is completed, the cleaning tank is communicated with the drying system, heated air is circulated between the cleaning tank and the drying system, and the vaporized solvent is condensed and recovered by a condenser. - In a dry cleaning machine that performs a solvent recovery process and a distillation process that distills and purifies the solvent contaminated by the cleaning process after the cleaning process, the cleaning system is depressurized during the cleaning process, and the degree of pressure reduction is is controlled so as to maintain the degree of reduced pressure within a set specific range, and also directly detects the heating steam temperature of the distiller, and maintains the steam temperature within a set specific range. A method for distilling a solvent in a dry cleaning machine, characterized in that: 2. A washing process in which a solvent is supplied into a washing tank that rotates at a low speed to wash the clothes in the washing tank, a dehydration process in which the washing tank is rotated at a high speed to remove liquid from the clothes after the washing process is finished; a drying/solvent recovery step in which the cleaning tank is communicated with the drying system after the completion of the liquid process, heated air is circulated between the cleaning tank and the drying system, and the vaporized solvent is condensed and recovered by a condenser; In a dry cleaning machine that performs a distillation process in which the solvent contaminated by the cleaning process is distilled and purified after the cleaning process is completed, a pressure reducing valve and an automatic opening/closing valve are installed in the heated steam supply pipe of the distiller, and a steam jacket is installed. A temperature detection sensor is directly disposed in the distillation valve, and a means is provided for automatically closing the automatic opening/closing valve when the detected value of the temperature detection sensor reaches the upper limit of the set temperature, and automatically opening the valve when the lower limit is reached. A vacuum pump is connected to a part of the system through an automatic on-off valve, and a pressure detection sensor is installed to detect the pressure in the distillation system, and the detected value of the pressure sensor is the upper limit of the set pressure reduction range. A solvent distillation apparatus for a dry cleaning machine, characterized in that the automatic on-off valve connected to the vacuum pump is provided with means for automatically closing the automatic on-off valve connected to the vacuum pump when the lower limit is reached, and automatically opening the valve when the lower limit is reached.