Abstract:
The object is to avoid contaminating the washing conversely by contaminated detergent and provide a dry cleaning machine and dry cleaning method, solving hygienic issues.  
     In a dry cleaning machine which supplies detergent from a detergent tank  11  to a washing tank  10  and washes the washing in the washing tank  10  and treats detergent used in the washing tank  10  by a filtering tank  16  and sends the treated detergent to the washing tank  10  to use detergent cyclically, wherein contaminating the washing conversely by washing can be prevented, as detecting contamination level of detergent discharged from the washing tank  10  while supplying detergent to the washing tank  10  and washing the washing, and when the detergent contamination level reached a prescribed threshold level, storing the detergent discharged from the washing tank  10  temporarily and sending the detergent to a distiller  14  and supplying fresh detergent from the detergent tank  11  to the washing tank  10.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     This invention relates to a dry cleaning machine using a solvent as a detergent and preventing contamination of the washing caused conversely by washing.  
         [0003]     2. Description of the Related Art  
         [0004]      FIG. 5  is showing a constitutional block diagram of a dry cleaning machine by prior art.  
         [0005]     In  FIG. 5 , a drum-formed washing tank  1  is for washing the washing by rotating drum, throwing the washing into the drum tank, supplying a detergent (tetrachloroethylene or the like). The contaminated detergent after using is stored in a lower tank  2 . This detergent is sent into a filtering tank  4  and forwarded to a refining tank  5  by a pressure pump  3 . In the refining tank  5 , the detergent is refined to remove odors, acids and colors with filters, activated carbon and the like and then returned into the drum tank  1  to be reused.  
         [0006]     In the dry cleaning machine shown in  FIG. 5 , washing power of the detergent is remarkably sunk by cyclical use, even though the contaminated detergent is refined in the refining tank. Therefore, in a conventional dry cleaning machine, a detergent collecting unit as shown in  FIG. 6  is appended. In this detergent  25  collection unit, the heavy contaminated detergent in the washing tank  1  is sent into a distiller  6 . The contaminated detergent in the distiller  6  is heated to vaporize the detergent and other moisture and the vaporized gas is forwarded to a condenser  7 . The vaporized gas in the condenser  7  is liquefied by chiller water and is separated to detergent and water through a water separator  8 . The detergent is sent to a collection tank  9  and the separated water is sent to a separated water tank  10 . The detergent collected in the collection tank  9  is forwarded to the washing tank  1  to be used.  
         [0007]     On the other hand, a dry cleaning machine has washing property as shown in  FIG. 7 . The washing property in  FIG. 7  shows phenomena of contaminator dissolving into the detergent and the washing property curve (a) shows contamination is maximized in a short time and is going down slowly after the peak. Thus, in the washing property, the detergent contamination becomes the maximum roughly at one minute and 30 seconds after starting, slightly depending on the washing type or contaminator type. In  FIG. 7 , the vertical axis indicates detergent contamination and the horizontal axis indicates washing time.  
         [0008]     The dry cleaning machine, shown in  FIG. 5 , uses cyclically refined detergent to send the contaminated detergent through a filtering tank and a refining tank. Owing to the detergent contamination becomes the maximum in a short time, shown in  FIG. 7 , there is apprehension to contaminate the washing conversely by washing. In addition, the detergent filtering in the filtering tank works well just after the dry cleaning machine running, but, as increasing washing cycle number, some waste threads, dirty oil or other dirt in the detergent stick on a filter and clog up the filter. When clogging up the filter, filtering efficiency is rapidly sinking and a volume of detergent flowing is going down. As washing performance cannot be kept if the volume of detergent flowing goes down, in general, increasing the detergent pressure in the filtering tank to keep the volume of detergent flowing maintains the washing performance of the dry cleaning machine. That, however, cannot solve the issue of contaminating the washing conversely by washing. Furthermore, there is apprehension that increasing detergent pressure in the filtering tank damages the filtering tank or the refining tank easily and then it possibly contaminates the washing by supplying contaminated detergent to the washing tank  
         [0009]     Even if reusing detergent distilled by the distiller shown in  FIG. 6 , the detergent contamination becomes the maximum in a short time after washing starting because of no deference on washing property of the dry cleaning machine shown in  FIG. 7 . There are still issues of contaminating the washing conversely by washing and bad hygiene.  
       SUMMARY OF THE INVENTION  
       [0010]     This invention has been accomplished to overcome the above drawbacks and an object of this invention is to avoid contaminating the washing conversely by contaminated detergent and provide a dry cleaning machine and method of dry cleaning, solving hygienic issues.  
         [0011]     In order to attain the objects, according to an aspect of this invention, in a dry cleaning machine including a detergent tank to store detergent, a washing tank and a filtering tank to treat used detergent, wherein the treated detergent is sent back to the washing tank for cyclical use, there is provided the dry cleaning machine comprising of detecting means for detecting contamination level of the detergent discharged from the washing tank while washing, storing means for storing the used detergent when the contamination level of detergent reaches prescribed threshold level and distilling means for distilling the used detergent, whereby fresh detergent is supplied from the detergent tank to the washing tank.  
         [0012]     In the dry cleaning machine mentioned above, before the detergent contamination becomes the maximum in a short time from starting washing the washing, the detergent channel is switched from washing tank-to-filtering tank to washing tank-to-contaminated detergent tank. During switching the detergent channel as mentioned above, fresh detergent is supplied to the washing tank and it can solves an issue to contaminate the washing conversely by contaminated detergent.  
         [0013]     Advantageously, in the above machine, wherein detecting the contamination level of the detergent in a channel from the filtering tank to the washing tank, when the contamination level indicate an abnormal value, shutting the channel and storing temporarily the detergent from the filtering tank and distilling the detergent by the distiller.  
         [0014]     In the machine, when detecting an abnormal value of contamination level of the detergent passed through the filtering tank, the detergent is distilled in the distiller after stored temporarily and reused. Then, rapid clogging up the filtering tank can be solved and cyclically use of the detergent can be worked.  
         [0015]     Preferably, a dry cleaning machine, comprising of a washing tank for washing the washing by detergent supplied from a detergent tank, a filtering tank for refining contaminated detergent discharged from the washing tank and supplying the refined detergent to the washing tank, a contamination detector for detecting contamination level of detergent after used in the washing tank, a contaminated detergent tank for storing contaminated detergent temporarily while shutting detergent supplying channel from the washing tank to the filtering tank when the contamination level is over prescribed threshold level, a distiller to distill the contaminated detergent from the contaminated detergent tank and a condenser for condensing vaporized contaminated detergent in the distiller and sending the condensed detergent to the detergent tank.  
         [0016]     In the dry cleaning machine mentioned above, by detecting contamination level of the detergent discharged from the washing tank with the contamination detector, the detergent channel from the washing tank to the filtering tank is switched to the contaminated detergent tank and the detergent is stored there, before the detergent contamination becomes the maximum in a short time after starting washing. After that, the contaminated detergent is sent to the distiller and vaporized in the distiller. The vaporized gas is forwarded to the condenser and condensed by chiller water and reused as refined detergent.  
         [0017]     Advantageously, the dry cleaning machine mentioned above, wherein the second detector is mounted in a channel to supply detergent from the filtering tank to the washing tank for detecting the detergent contamination level in the channel.  
         [0018]     In this dry cleaning machine, the detergent contamination, after the filtering tank, can be detected by the second detector mounted there. In the other word, when the detergent contamination after the filtering tank increasing, it makes definition of some damages in the filter occurred and supplying the detergent from the filtering tank to the washing tank can be stopped and then contaminating the washing conversely by washing can be prevented.  
         [0019]     Advantageously, the all dry cleaning machines mention above, wherein the detector for detergent contamination level is of an image processing means, such a CCD camera or the like, to sense the detergent contamination level.  
         [0020]     In these all dry cleaning machines, as the detector for detergent contamination is a CCD camera, it cannot sense only the detergent contamination but also a lot of waste threads mixed in the detergent. Therefore, it can prevent rapid clogging up the filtering tank.  
         [0021]     In order to attain the objects, according to an aspect of this invention, there is provided a method of dry cleaning comprising the steps of supplying the washing and detergent to wash the washing in a washing tank, detecting detergent contamination level just after washing while treating used detergent in a filtering tank and reusing the detergent in the washing tank and shutting the detergent supply to the filtering tank and supplying fresh detergent to the washing tank to prevent the detergent contamination level is over prescribed threshold level when the detergent contamination level reaches prescribed threshold level.  
         [0022]     In this cleaning method, contaminating the washing conversely by washing can be prevented as detecting the detergent contamination level discharged from the washing tank during washing. Then, the detergent can be used by circulating and also reused by distiller.  
         [0023]     Advantageously, the cleaning method mentioned above, wherein the contamination level of detergent, supplied from the filtering tank to the washing tank, is detected and above channel from the filtering tank to the washing tank is closed to shut the detergent supply when the contamination level indicates an abnormal value.  
         [0024]     In the cleaning method, contaminating the washing conversely by washing can be prevented and also the filtering tank damage can be detected because contamination level of the detergent transmitted from the filtering tank to the washing tank is detected. As a matter of course, when detecting rapidly increased contamination of the detergent, it is defined to occur some damages on the filter and then indicating or warning of the filter damage can urge to replace filter of the filtering tank.  
       EFFECT OF INVENTION  
       [0025]     As mentioned above, according to this invention, the dry cleaning machine detects detergent contamination discharged from a washing tank then if the contamination level goes over prescribed value, stores the contaminated detergent in a contaminated detergent tank temporarily and supplies fresh detergent to the washing tank to prevent contaminating the washing conversely by washing. Therefore, the dry cleaning machine can use circulating detergent and clean the washing to supply clean detergent always not contaminating the washing to the washing tank.  
         [0026]     According to this invention, the dry cleaning machine can prevent to contaminate the washing conversely by washing as cutting off the line to supply detergent from a filtering tank to a washing tank and supplying fresh detergent to the washing tank when detecting the contamination of detergent supplied from the filtering tank to the washing tank. Then, this is an excellent hygienic cleaning method.  
         [0027]     According to this invention, the dry cleaning machine can detect reducing the light transmittance caused by darkened detergent with contamination as taking images of the detergent discharged from the washing tank by CCD camera. Moreover, advantageously the dry cleaning machine can prevent immoderate clogging of the filtering tank as judging abnormal condition by processing the image data even if a lot of waste thread or down mix into the detergent. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0028]      FIG. 1  is a constitutional block diagram, showing one embodiment of a dry cleaning machine according to this invention;  
         [0029]      FIG. 2A, 2B  are sectional views of examples of contamination detectors;  
         [0030]      FIG. 3  is a graph and timing charts to explain the cleaning method which prevents contaminating the washing conversely by washing to detect detergent contamination in a dry cleaning machine according to this invention;  
         [0031]      FIG. 4  is a graph and timing charts to explain the cleaning method which prevents contaminating the washing conversely by washing to detect detergent contamination supplied from the filtering tank in a dry cleaning machine according to this invention;  
         [0032]      FIG. 5  is a block diagram to explain a dry cleaning machine by prior art;  
         [0033]      FIG. 6  is a block diagram to explain a dry cleaning machine by prior art;  
         [0034]      FIG. 7  is a graph to explain washing property of a dry cleaning machine; 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0035]     Some embodiments of dry cleaning machines and cleaning methods according to this invention will now be described with reference to the attached drawings.  
         [0036]      FIG. 1  is showing a block diagram of one embodiment of a dry cleaning machine according to this invention. In  FIG. 1 , a washing tank  10  is a shower drum type for washing the washing and preferably soaking type, shower type or jet type is effective and also combination type of these types is effective. A detergent tank  11  stores detergent and a rinse tank  12  stores rinse. Washing is done after inputting the washing and detergent (tetrachloroethylene or the like) into the washing tank  10 . The detergent for initial use can be supplied directly through fresh detergent line L 1  to the washing tank  10  or can also be supplied through circulating line L 3 , L 4 .  
         [0037]     The detergent, discharged from the washing tank  10 , is sent by pressure to the filtering tank  16  through a detergent discharging line L 2 , next a button trap  13  and next a circulating line L 3  having a circulation pump P 1  in the line. The detergent after the filtering tank  16  is supplied to the washing tank  10  through a circulating line  4 . The detergent, discharged from the washing tank  10 , is monitored on contamination level by a contamination detector D 1 , mounted in the detergent discharging line L 2 . The detergent, supplied from the filtering tank  16  to the washing tank  10 , is monitored by a contamination detector D 2 , mounted in the circulating line L 4 . By way of the contamination detectors D 1 , D 2 , a CCD camera, a couple of light emitting elements and light receiving elements or a module of reflective millers and a couple of light emitting elements and light receiving elements or the like is used.  
         [0038]     This dry cleaning machine includes of a distiller  14  for distilling contaminated detergent to reuse the detergent, a condenser  15  for condensing gas vaporized in the distiller  14  and a contaminated detergent tank  17  for storing the contaminated detergent temporarily. The detergent to the distiller  14  is supplied through the button strap  13  or the contaminated detergent tank  17 .  
         [0039]     Switch valves V 3 , V 6  are mounted in the circulating line L 3 , wherein a contaminated detergent returning line L 5  is branched off. The contaminated detergent returning line L 5 , wherein switching valves V 8 , V 9  are mounted, is connected to the contaminated detergent tank  17 . The contaminated detergent tank  17  is connected to the distiller  14  by the contaminated detergent returning line L 6 , wherein a switching valve V 10  is mounted. Furthermore, the distiller  14  is connected to the condenser  15  by a vaporized gas sending line L 7 . The condenser  15  is connected to the detergent tank  11  by a condensed liquid sending line L 8 , for supplying condensed and liquefied detergent in the condenser  15  to the detergent tank  11 .  
         [0040]     A control unit  20  including CPU, provided in the dry cleaning machine, receives data output from the contamination detectors D 1 , D 2  and controls the switching valves V 1  to V 10  with processing the data from the contamination detectors D 1 , D 2 .  
         [0041]     In the next, the contamination detectors D 1 , D 2  will be described with reference to  FIGS. 2A and 2B . As the contamination detectors D 1  D 2  have the same structure, only the, contamination detector D 1  will be described herein. In  FIG. 2A , the contamination detector D 1  is mounted in the detergent discharging line L 2  or the circulating line L 4 . A CCD camera  23  and a light emitting element  21 , as the contamination detector D 1 , are placed opposite to each other sandwiching a transparent pipe  22  in the middle. The light emitting element  21 , the transparent pipe  22  and the light receiving section of the CCD camera  23  are covered with a shade material  24  to cut off external light into the transparent pipe  22 . Further, in  FIG. 2B , the contamination detector D 1  is mounted in the detergent discharging line L 2  or the circulating line L 4 . The light emitting element  21  and a light receiving element  25 , as the contamination detector D 1 , are placed opposite to each other sandwiching a transparent pipe  22  in the middle. The light emitting element  21 , the transparent pipe  22  and the light receiving element  25  are covered with a shade material  24  to cut off external light into the transparent pipe  22 . The contamination detector D 1  is mounted by connecting the detergent discharging line L 2  or the circulating line L 4  on the both end of the contamination detector D 1 .  
         [0042]     Preferably, the light emitting element  21  is placed at the same side of the CCD camera  23  or the light receiving element  25  to detect the detergent contamination by taking a image of the reflective light or receiving the reflective light, instead of placing the light emitting element  21  opposite to the CCD camera  23  or the light receiving element  25 .  
         [0043]     In the next, working of the contamination detectors D 1 , D 2  in  FIG. 2A  will be described with reference to  FIGS. 1, 2A . The light, radiated from the light emitting element  21 , irradiates the detergent flowing in the transparent pipe  22  through the transparent pipe  22 . The light, passing the detergent, is sensed by the CCD camera  23 . The image data from the CCD camera  23  is inputted to the control unit  20  and judged whether over or under the prescribed threshold level on each pixel. The image data on each pixel is defined as digital signal “ 1 ” for over the prescribed threshold level and digital signal “ 0 ” for under the prescribed threshold level. And then, judgement whether over the threshold level or not is done by total sum of all digital signals of each pixel of the image and defines “1” for over the threshold level and “0” for under the threshold level. When the judgement of total sum is “1”, the detergent contamination is defined to reaches the prescribed level. Thus, as the detergent contamination is defined numerically and the contamination is detected by total sum of each pixel digital signals, on the situation of detergent contamination mixed with a lot of waste thread or down waste the detection can be done.  
         [0044]     The contamination detectors D 1 , D 2  in  FIG. 2B  will be described here. The contamination detectors D 1 , D 2  are mounted in the detergent discharging line L 2  or the circulating line L 4 . The light from the light emitting element  21  is received by the light receiving element  25  through the transparent pipe  22 . The output of the light receiving element  25  depends on light transmittance changing caused by the detergent contamination level and indicates the smaller transmitted light power the more detergent contamination. Then, the control unit  20  judges “1” by output from the contamination detectors D 1 , D 2  when the output of the light receiving element  25  reaches the prescribed level.  
         [0045]     If the contamination detectors D 1 , D 2  in  FIG. 2B  are mounted in the circulation line L 4 , it can detect to supply the contaminated detergent to the washing tank  10  or can judge to occur the filter damage in the filtering tank  16 . Setting low detecting level (threshold level) for detergent contamination, damage of the filtering tank can be detected earlier and contaminating the washing conversely by washing can be solved. Preferably, inputting the output of the contamination detector D 2  into the control unit  20  and monitoring time-dependent change of detergent contamination change, the filter damage of the filtering tank  16  can be detected by rapid change of the detergent contamination.  
         [0046]     In the next, a dry cleaning method to prevent contaminating the washing conversely by washing in a dry cleaning machine according to this invention will be described with reference to  FIGS. 1, 3  and  4 . In  FIG. 3 -A shows washing property curves (a), (b) and  FIG. 3 -B shows working condition of the circulating pump P 1  and FIGS.  3 -C, D, E and F show each working condition of switching valves V 3 , V 6  and V 7 , V 8  and V 9 , V 2  and V 2 .  
         [0047]     On this embodiment of dry cleaning machines, the switching valves V 3 , V 6 , V 7  are opened and the switching valves V 8 , V 9  are closed in starting operation. As the switching valves V 4 , V 5  are opened in certain level, the detergent and rinse are mixed to be usable. The mixed detergent is supplied from the filtering tank  16  to the washing tank  10  through the circulating line L 3  by operating the circulating pump P 1 . By rotating the drum of the washing tank  10 , washing the washing is started. The contamination level of the detergent, discharged from the washing tank  10 , is detected by the contamination detector D 1 . The output of the contamination detector D 1  is inputted into the control unit  20 . As shown in  FIG. 3 -A, the property shows the detergent contamination becomes the maximum in a short time (time T 2 ) after starting washing. Therefore, eliminating the maximum peak, when the output of the contamination detector D 1  goes over the prescribed threshold level (time T 1 ), the switching valves V 6 , V 7  are closed as shown in  FIG. 3D  to cut off the circulating line L 3  from the washing tank  10  to the filtering tank  16  and the circulating line L 4  from the filtering tank  16  to the washing tank  10 . In the other hand, the switching valves V 8 , V 9  in the detergent returning line L 5  are opened as shown in  FIG. 3 -E.  
         [0048]     In the next, when the switching valves V 6 , V 7  are closed and the switching valves V 8 , V 9  in the contaminated detergent return line L 5  are opened, the contaminated detergent is supplied to the contaminated detergent tank  17  through the contaminated detergent return line L 5 . In the meantime, the switching valves V 1 , V 2  is opened and detergent, mixed by the detergent and rinse from the detergent tank  11  and the rinse tank  12 , is supplied directly to the washing tank and the washing is washed. After passing the prescribed time (the time between T 1  and T 2  in  FIG. 3 -A is required time that detergent contamination is changing from the prescribed threshold level to the maximum), the switching valves V 6 , V 7  are opened and the switching vales V 8 , V 9  and V 1 , V 2  are closed. Then the initial condition is set again. The contaminated detergent, sent to the contaminated detergent tank  17 , is forwarded at suitable intervals to the distiller  14  through the contaminated detergent return line L 6 . The contaminated detergent is heated and vaporized in the distiller  14  and the vaporized gas of the contaminated detergent is forwarded to the condenser  15  to be condensed and liquefied by chiller water. The liquefied detergent is sent to the detergent tank  11  through the condensed detergent transport line L 8 .  
         [0049]     Thus, the control unit  20  can improve the washing property like Washing property curve as shown in  FIG. 3 -B, for supplying fresh detergent directly to the washing tank by controlling each switching vales, sending control signals to each switching valve before the detergent contamination becomes the maximum. Then, contaminating the washing conversely by washing can be solved and cyclically use of the detergent can be worked.  
         [0050]     In the next, prevention to contaminate the washing conversely caused by filer damage of the filtering tank in a dry cleaning machine will be described with reference to  FIG. 4 . The curve (b) in  FIG. 4 -A shows the washing property curve by the operation method to prevent above conversely contamination. The curve (c) in  FIG. 4 -A shows contaminated detergent leaking when the filter of the filtering tank is damaged. Solving to contaminate the washing conversely by such filter damage, the contamination detector D 2  is mounted in the circulating line L 4  from the filtering tank  16  to the washing tank  10 .  
         [0051]     The contamination detector D 2  is detecting the contamination level of detergent flowing in the circulating line L 4 . When the output of the contamination detector D 2  is over the prescribed threshold level (in the condition as shown in FIGS.  4 -A, C), the switching valve V 7  is closed and the switching valve V 9  is opened as shown in FIGS.  4 -D, F. Then, the detergent passed through the filtering tank  16  is sent to the contaminated detergent tank  17 . In the meantime, the switching valves V 1 , V 2  are opened as shown in  FIG. 4 -G and fresh detergent is supplied to the washing tank  10  through fresh detergent line L 1  and this condition is kept until washing finished. The switching valves V 6 , V 8  are kept as shown in FIGS.  4 -C, E. The contamination level of the detergent, discharged from the washing tank  10 , is detected by the contamination detector D 1  as shown in  FIG. 3 -A. When the detergent contamination level is over the prescribed threshold level, the switching valves V 6 , V 7  is closed to cut off the circulating line L 4  from the washing tank  10  to the filtering tank  16  and the switching valves V 8 , V 9 , mounted in the contaminated detergent return line L 5 , are opened to send the contaminated detergent to the contaminated detergent tank  17 .  
         [0052]     On the other hand, the switching valve V 10 , mounted in the contaminated detergent return line L 6 , is opened and the contaminated detergent in the contaminated detergent tank  17  is forwarded to the distiller  14 . The vaporized gas by heating and vaporizing the contaminated detergent in the distiller  14  is sent through the vaporized gas transport line L 7  to the condenser  15  to be condensed and liquefied by chiller water. The liquefied detergent is returned to the detergent tank  11  through the condensed detergent transport line L 8 .  
         [0053]     Detecting the contamination of the detergent from the filtering tank  16  and controlling as mentioned above can give the washing property as shown in  FIG. 4 -D. In addition, as the filter in the filtering tank  16  can be exchanged after washing the washing finished, the maintenance of the filtering tank is made easy. Preferably, in case of detecting abnormal condition by the contamination detector D 2 , indicating or alarming filter damage, then stopping operation temporarily, then exchanging filter in the filtering tank  16 , then restarting operation is effective.  
         [0054]     Preferably, instead of detecting the detergent contamination by inputting image data by a CCD camera continuously to the control unit, detecting both of image data by a CCD camera and output signal by a light receiving element and inputting the data and the signal to the control unit to sense the detergent contamination is also effective.  
         [0055]     Advantageously, a dry cleaning machine having only one contamination detector D 1  can solve issue to contaminate the washing conversely by washing. Mounting the second contamination detector D 2  in the dry cleaning machine can prevent more effectively contaminating the washing conversely by washing.