JPH0649118B2 - Method and device for distilling solvent in dry cleaning machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a dry cleaning machine using a solvent, in which a solvent contaminated by washing is distilled again while maintaining a stable state when the solvent is re-refined by distillation. The present invention relates to a distillation method and apparatus capable of

[Conventional technology]

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

In FIG. 2, reference numeral 1 denotes a solvent main tank, and the solvent in the main tank is transferred to a three-way valve 2 → pump 3 → filter 4 →
The automatic open / close valve 5 → the cleaning tank 6 → the automatic open / close valve 7 → the button trap 8 → the method of cleaning while circulating to the main tank 1 and the high liquid float 9 or the low liquid float 10 without flowing into the main tank were set. There is a method of keeping the liquid surface and collecting and washing. In any case, the cleaning process is performed by rotating the inner body of the cleaning tank 6 at a low speed in the forward and reverse directions except for a special case, and after the cleaning process, the solvent contaminated by the cleaning process is sent to the distiller 11 and then automatically opened and closed. The valve 60 is opened to introduce the clean solvent in the clean oil tank 14 into the cleaning tank 6 for rinsing, and the solvent used for rinsing is returned to the main tank 1.

After the cleaning process is completed, the inner body of the cleaning tank 6 is rotated at a high speed to perform the liquid removing process. At that time, the automatic opening / closing valve 1
5, 5 and 16 are in the open state, the dust filter 17 and the fan 1
8. Since the drying system path including the drying condenser 19, the heater 20 and the cleaning tank 6 is in communication with each other, when the fan 18, the heater 20 and the condenser 19 are driven, the air heated by the heater 20 is transferred to the cleaning tank 6 and the cleaning tank 6. The clothes are dried by circulating between them with a drying system path, and the solvent vaporized by this is condensed by the drying condenser 19, and thus the liquefied solvent is collected in the collection tank 21. Then, a cooling step of gradually cooling the inside of the system is performed to complete one cycle of cleaning.

Then, after the washing step, until the slow cooling step ends, the solvent contaminated by the washing step is sent to the distiller 11,
Steam is introduced into the steam jacket 11a at the bottom of the distiller 11 to heat the solvent in the distiller 11, the solvent vaporized by this is condensed by the distillation condenser 12, and the obtained clean solvent is separated into a water separator. A distillation step of storing in a clean oil tank 14 via 13 is performed. The solvent stored in the clean oil tank 14 is used for swishing in the next cleaning.

By the way, the general time required for the series of dry cleaning steps is about 6 minutes for the cleaning step in which the solvent is circulated, about 4 minutes for the scrubbing step, and about 3 minutes for the deliquoring step.
Minutes, about 15 minutes for drying and solvent recovery process, about 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 control of the heat source in the distillation step is performed by a distiller.
A pressure reducing valve 23 on the steam supply pipe 22 leading to the steam jacket 11a of 11
Was arranged, and the pressure reducing valve 23 was manually adjusted so that steam at a desired temperature could be obtained. For example, the pressure reducing valve 23 was operated to distill at 150 ° C. with a vapor pressure of 4 kg / cm ² .

It is also known that the distillation system such as a distiller, a condenser, a water separator, and a clean oil tank is decompressed by a vacuum pump to carry out distillation at a predetermined decompression degree (Japanese Patent Laid-Open No. 61-170492 "Dry"). Vacuum Distillation Method in Cleaning ”) [Problems to be Solved by the Invention] As described above, the conventional distillation method in dry cleaning is controlled only by the vapor pressure (heating temperature) or only the degree of pressure reduction in the distillation system. Therefore, the balance between the evaporation amount on the distiller side and the cooling capacity on the condenser side is lost, and the dirty solvent in the distiller is blown up to the condenser side (this is called bumping), and it is necessary for the next cleaning within a predetermined time. There was a problem that the amount of distillation that could be done was not possible.

That is, the capacity of the condenser of the distillation apparatus is related to the problem of the installation space and the cost, so that the minimum amount of solvent required for one dry cleaning in the dry cleaning apparatus can be distilled within a predetermined time. In general, the temperature control by the pressure reducing valve changes the distillation temperature when the primary pressure changes, and the degree of pressure reduction in the distillation system also changes with time or the distillation temperature. The evaporation amount of the solvent changes depending on both the distillation temperature and the degree of depressurization in the distillation system.Therefore, in the control of only the vapor pressure (distillation temperature) or only the degree of depressurization in the system, the distillation process It is difficult to surely prevent bumping, which tends to occur mainly in the initial stage, and there is a problem that a distillation amount becomes insufficient if conditions are set so that bumping can be surely prevented.

The present invention improves the problems of the prior art as described above, surely prevents bumping, and provides a distillation method and an apparatus thereof in a dry cleaning machine capable of efficiently distilling with a distillation amount commensurate with the cooling capacity of a condenser. The purpose is to provide.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, the present invention reduces the pressure in the distillation system during the distillation step of dry cleaning, and
The decompression degree is controlled so as to maintain the decompression degree within a set specific range, the steam temperature for heating the distiller is directly detected, and the distillation temperature of the distiller is set within the set specific range. It is characterized by controlling so as to maintain the temperature.

Further, according to the present invention, a decompression pipe and an automatic opening / closing valve are arranged in the heating steam supply pipe of the distiller, and a temperature detection sensor is directly arranged in the steam jacket, and the detection value of the temperature detection sensor is within a set temperature range. When the upper limit of is reached, the on-off valve provided in the steam supply pipe is automatically closed to temporarily suspend steam heating, and when the lower limit is reached, a means for automatically opening the on-off valve to continue steam heating is provided, In addition, a vacuum pump is connected to a part of the distillation system via an on-off valve, and a pressure detection sensor that detects the pressure in the distillation system is installed, and the detection value of the pressure detection sensor is set in the decompression range. When the upper limit (vacuum degree) is reached, the on / off valve leading to the vacuum pump is automatically closed to temporarily stop the depressurization by the vacuum pump, and when the lower limit (low vacuum degree) is reached, the on / off valve is opened to vacuum. A means for continuing decompression with a pump was provided. And wherein the door.

[Action]

As described above, the present invention controls both the distillation temperature and the degree of depressurization in the distillation system so as to meet the set conditions. Therefore, the conventional distillation method in which only the distillation temperature is controlled so as to meet the set conditions , Or like the distillation method that controls only the degree of decompression in the system to match the set conditions, the balance between the evaporation amount on the distiller side and the cooling capacity on the condenser side is disturbed, and the dirty solvent in the distiller is removed. When there is no possibility of blowing up to the condenser side and there are upper and lower limits for the distillation temperature and the degree of pressure reduction in the distillation system, if there is a change in temperature or degree of pressure reduction due to a change in secondary pressure due to the pressure reducing valve. In addition, the distillation temperature and the degree of reduced pressure can be adjusted according to the fluctuations to perform smooth and efficient distillation.

〔Example〕

 An embodiment of the present invention will be described below with reference to FIG.

In FIG. 1, 1 is a main tank, 2 is a three-way valve, 3 is a pump, 4 is a filter, 5 is an automatic opening / closing valve, 6 is a washing tank, 8 is a button trap, 11 is a distiller, and 12 is for distillation. A condenser, 13 is a water separator, 14 is a clean oil tank, 15 and 16 are automatic opening / closing valves, 17 is a dust filter, 18 is a fan, 19 is a drying condenser, 20 is a heater, and 21 is a solvent recovery tank during the drying process. In the same manner as described with reference to FIG. 2, the cleaning step, the rinsing step, the drying / solvent recovery step, and the distillation step can be performed.

In the present invention, the temperature detecting sensor 100 is arranged in the steam jacket 11a of the distiller 11, and the manual pressure reducing valve 23 and the automatic opening / closing valve 101 are arranged in the steam supply pipe 22 leading to the steam jacket 11a of the distiller. However, when it is detected that the vapor temperature detected by the temperature detection sensor 100 is the upper limit of the set temperature range, for example, 150 ° C., the automatic opening / closing valve 101 is closed, and the lower limit, for example, 145
When it is detected that the temperature is ° C, the control unit 102 automatically controls to open the automatic opening / closing valve 101.

Further, in the present invention, the distiller 11, the distillation condenser
A vacuum pump 50 is connected to a part of a distillation system path consisting of 12, a water separator 13, a clean oil tank 14, etc., for example, the clean oil tank 14 via an automatic opening / closing valve 51, and a vacuum degree in the distillation system path. (Decompression degree) is detected by the pressure gauge 53, and the decompression degree detected by the pressure gauge 53 is the upper limit of the set range, for example, 20
When it reaches 0 Torr, the automatic open / close valve 51 is closed and the vacuum pump
When the pressure reduction by 50 is interrupted and the lower limit, for example, 210 Torr is detected, the automatic opening / closing valve 51 is opened and the vacuum pump 50 is opened.
The control unit 54 automatically controls to reduce the pressure in the distillation system by.

In addition, during distillation, the inside of the distillation system should be completely blocked from other routes. That is, 57 is a manual on-off valve provided in a pipe line for sending the cleaning solvent from which water has been separated by the water separator 13 to the cleaning oil tank 14, 58, 58 'are water separators 13, 1
Manual open / close valve provided on 3'drain pipe, 52 is clean oil tank 14
Automatic open / close valve installed at the clean solvent inlet of 60, clean oil tank 60
An automatic opening / closing valve provided in a pipe line from 14 to the washing tank 6, 62 is an automatic opening / closing valve provided in a pipe line for transferring the clean solvent obtained by the drying / solvent recovery process to the clean oil tank 14, and at the time of distillation, Close valves 60,62,58,58 'and open valves 57,51,52,
The vacuum pump 50 is driven to carry out distillation.

Since the solvent distillation apparatus in the dry cleaning of the present invention has the above-mentioned configuration, the valves 60, 62, 58 and 5 are used.
When 8'is closed and valves 57, 51, 52 are opened, and the vacuum pump 50 is driven to carry out distillation, the pressure in the distillation system is kept within a set range, for example, 200 Torr to 210 Torr, and at the same time the vapor of the distiller is vaporized. The heating temperature of the jacket 11a is kept in a set range, for example, 150 ° C to 145 ° C, and thus both the distillation temperature and the degree of pressure reduction are controlled, so that the evaporation amount can be efficiently distilled with the evaporation amount corresponding to the cooling capacity of the condenser 12. it can.

In particular, in the present invention, as the temperature control method of the distiller 11, not simply by adjusting the pressure reducing valve 23 as in the conventional case,
When the actual temperature in the steam jacket 11a is detected and the upper limit of the setting range (for example, 150 ° C) is detected, the automatic opening / closing valve 101 is closed to temporarily stop the heating, and the lower limit of the setting range (for example, 14 ° C).
(5 ℃) is detected, the automatic open / close valve is opened and heating is restarted. Therefore, the distillation temperature is adjusted according to fluctuations in the degree of decompression in the distillation system path and fluctuations in the condenser cooling capacity, and the distillation system path is also adjusted. The control of the degree of decompression within the upper limit (eg 200 Tor
r) is detected, the automatic opening / closing valve 51 is closed to stop the pressure reduction, and when the lower limit (for example, 210 Torr) is detected, the automatic opening / closing valve 51 is opened and the pressure reduction is restarted. By adjusting the degree of pressure reduction in the system, it is possible to prevent bumping that tends to occur mainly in the initial stage of the distillation process and to carry out smooth and efficient distillation.

〔The invention's effect〕

As described above, according to the present invention, since both conditions of the distillation temperature and the degree of pressure reduction in the distillation system are controlled so as to be maintained within a set range, bumping that tends to occur at the beginning of the distillation process is prevented. It has the effect of efficiently distilling with an evaporation amount commensurate with the cooling capacity of the condenser.

BRIEF DESCRIPTION OF THE DRAWINGS 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 ... Washing tank, 5,7,15,16,51,52,60,62 ... Automatic open / close valve, 8 ... Button trap, 11 ... Distiller, 11a ...
Distiller steam jacket, 12 ... Distilling condenser, 13
…… Moisture separator, 14 …… Clean oil tank, 17 …… Dust filter, 18 …… Juan, 19 …… Dry condenser, 20 ……
Heater, 22 ... Steam supply pipe, 23 ... Pressure reducing valve, 100 ... Temperature detection sensor, 101 ... Automatic opening / closing valve, 102 ... Control section, 50
...... Vacuum pump, 53 ...... Pressure gauge, 54 ...... Control section.

Claims (2)

[Claims] 1. A cleaning step of supplying a solvent to a cleaning tank rotating at a low speed to clean an object to be cleaned in the cleaning tank, and a cleaning tank rotating at a high speed after completion of the cleaning step to remove liquid from the object to be cleaned. After the liquid process and the dewatering process, the washing tank is connected to the drying system passage to circulate the heated air between the washing tank and the drying system passage, and the vaporized solvent is condensed by the condenser and recovered. In a dry cleaning machine that performs a solvent recovery step and a distillation step for distilling away and purifying the solvent contaminated by the cleaning step after the cleaning step, in the distillation step, the distillation system path is depressurized, and the degree of depressurization is adjusted. ,
It controls so as to maintain the decompression degree within a set specific range, directly detects the steam temperature for heating the distiller, and
A method for distilling a solvent in a dry cleaning machine, characterized in that the distillation temperature of the distiller is controlled so as to maintain a temperature in a set specific range. 2. A cleaning step of supplying a solvent to a cleaning tank rotating at a low speed to clean an object to be cleaned in the cleaning tank, and a cleaning tank rotating at a high speed after completion of the cleaning step to remove liquid from the object to be cleaned. After the liquid process and the dewatering process, the washing tank is connected to the drying system passage to circulate the heated air between the washing tank and the drying system passage, and the vaporized solvent is condensed by the condenser and recovered. In a dry cleaning machine that performs a solvent recovery step and a distillation step for distilling away and purifying the solvent contaminated by the cleaning step after completion of the cleaning step, a pressure reducing valve and an automatic opening / closing valve are provided in a heating vapor supply pipe of the distillation machine. At the same time, a temperature detecting sensor is directly arranged on the steam jacket, and the automatic opening / closing valve is automatically closed when the detected value of the temperature detecting sensor reaches the upper limit of the set temperature, and automatically opened when the lower limit is reached. Provided, A vacuum pump is connected to a part of the distillation system via an automatic opening / closing valve, and a pressure detection sensor that detects the pressure in the distillation system is installed, and the detection value of the pressure detection sensor is set. A device for distilling a solvent in a dry cleaning machine, comprising means for automatically closing the automatic opening / closing valve reaching the vacuum pump when the upper limit of the range is reached, and automatically opening when the lower limit is reached.