Abstract:
A vacuum clean-out system including a separator chamber and associated collection chamber for removing liquid material and debris from a vacuum output and providing a vacuum return line free of contaminants. A vacuum exhaust line is coupled to a cyclonic separator chamber that induces a circular rotation within the incoming vacuum stream, causing the liquid and debris to impinge the chamber&#39;s surfaces and fall to the bottom thereof while the “clean” vacuum is drawn upwards into a return line. The collection chamber is maintained at the same negative pressure as the separator chamber so that the accumulating liquid and debris easily drains into the collection chamber. A sensor associated with the collection chamber may be used to determine when the collection chamber is full and needs to be discharged. At that point, the separator chamber is isolated from the collection chamber, the collection chamber is vented and the accumulated material is discharged and/or analyzed. Advantageously, the separator chamber remains under negative pressure and continues the vacuum clean-out process uninterrupted.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims the benefit of U.S. Provisional Application No. 60/849,896, filed Oct. 7, 2006. 
     
    
     TECHNICAL FIELD  
       [0002]     The present invention relates to a vacuum clean-out system and, more particularly, to a vacuum clean-out system including a multi-chamber arrangement for separating waste material from the vacuum stream and isolating the collected waste material from the vacuum flow, providing an uninterrupted vacuum return line free of contaminants.  
       BACKGROUND OF THE INVENTION  
       [0003]     There are many applications, primarily industrial applications, where a vacuum system is used to hold semiconductor wafers in a fixture, create a controlled environment and/or remove various types of unwanted material. It is preferable to utilize a closed system where the negative pressure is constantly maintained and the removed material is separated out from the return vacuum flow so that the vacuum line returns to operation free from any contaminants which could otherwise cause problems with the vacuum pump.  
         [0004]     Many appropriate vacuum systems are well known and used in the art, where such systems may be used in either a “dry” vacuum environment or a “wet” vacuum environment. A common problem with all systems, however, is the need to periodically clean the vacuum removal system to eliminate the particulate matter that has accumulated over time. In systems utilizing a separator as a holding tank for the particulate, the separator itself needs to be periodically cleaned, or the vacuum efficiency will begin to decrease and/or some of the particulate matter will pass through the separator and may re-enter the system.  
         [0005]     Such periodic cleaning has previously been done by so-called “backflow” methods where a blast of pressure is directed in a reverse direction to unclog dry separators of any particulate matter. Such a system when used with a dry-type separator causes unnecessary mess due to particles or contaminants being blown out of the device into the environment or into a special receptacle. Such a system will still clog after a period of time and requires a manual teardown and reassembly of the separator to restore the proper vacuum flow through the system. Wet separators also require periodic shutdown of the system to drain and clean the separator and then replenish the separator material.  
         [0006]     Thus, it would be desirable to develop a vacuum system that provides automatic, periodic cleaning of the accumulating waste in such a manner that the system does not need to be shut down, manually cleaned and then re-charged.  
       SUMMARY OF THE INVENTION  
       [0007]     The need remaining in the art is addressed by the present invention which relates to a vacuum clean-out system and, more particularly, to a vacuum clean-out system including an arrangement for separating waste material from the vacuum stream and isolating the collected waste material from the vacuum flow, providing a vacuum return line of constant pressure and free of contaminants, and permitting the discharge of isolated waste material without interrupting the vacuum flow.  
         [0008]     In accordance with the present invention, a vacuum line clean-out system comprises a first, separator chamber and a second, collection chamber coupled to the separator chamber, where the collection chamber can be periodically isolated from the separator chamber to discharge accumulated waste material without interrupting the vacuum clean-out process within the separator chamber.  
         [0009]     In one embodiment of the present invention, the separator chamber is configured to induce a cyclonic flow within the incoming vacuum waste stream, causing the liquid and debris within the stream to impinge the chamber&#39;s surfaces and fall towards the bottom of the chamber, while the “clean” vacuum flow is drawn upwards into a clean vacuum return line. The collection chamber is connected to a drain output of the separator chamber and receives the liquid/debris as it moves downward out of the separator chamber. The collection chamber is also coupled to the vacuum return line to maintain the same negative pressure as the separator chamber, allowing the liquid/debris to easily drain.  
         [0010]     A sensor may be used in association with the collection chamber to indicate when then collection chamber needs to be emptied (referred to as a discharge process). Alternatively, the discharge of the collection chamber may be manually controlled, or configured to occur on a periodic basis regardless of the volume of accumulated waste material.  
         [0011]     It is an aspect of the present invention that the separator chamber is isolated from the collection chamber during the discharge process, thus allowing for the vacuum clean-out process to continue within the separator chamber during discharge. Any liquid/debris that accumulates during the discharge process will thus collect at the bottom of the separator chamber and be transferred to the collection chamber once the discharge process is completed, the negative pressure is re-established in the collection chamber and the connection between the two chambers is re-opened.  
         [0012]     In one embodiment of the present invention, the vacuum return line within the separator chamber may further include a filtering element, pressure reducing orifice, and/or condensing elements to further ensure that any liquid and/or debris within the separator chamber is not permitted to enter the vacuum return line.  
         [0013]     Various arrangements for introducing cyclonic flow into the inventive system may be used including, but not limited to, tapered inner walls within the separator chamber itself, or the inclusion of a diverter within the separator chamber for initiating the cyclonic action.  
         [0014]     Other and further embodiments and features of the present invention will become apparent during the course of the following discussion and by reference to the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]     Referring now to the drawings,  
         [0016]      FIG. 1  shows, in detail, an exemplary vacuum line clean-out separator system formed in accordance with the present invention;  
         [0017]      FIG. 2  illustrates the system of  FIG. 1  at a point in time when the process of discharging the accumulated waste material from the collection chamber is initiated;  
         [0018]      FIG. 3  illustrates an alternative embodiment of the present invention, including a discharge analysis system for evaluating the discharged waste material and utilizing the evaluation to control various aspects of the industrial application associated with the vacuum removal system; and  
         [0019]      FIG. 4  illustrates an alternative embodiment of a vacuum line clean-out separator system of the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0020]      FIG. 1  illustrates an exemplary vacuum line clean-out separator system  10  formed in accordance with the present invention. System  10  is used to remove liquid waste material and debris from an associated industrial application (not shown), using a process vacuum line, such as vacuum line  19  shown in  FIG. 1 . System  10  functions in a manner that first separates out the liquid material and debris from the incoming vacuum flow within a separator chamber, then allows the liquid/debris to drain into an associated collection chamber while the “clean” vacuum is returned to the system via a clean vacuum return line. It is an important aspect of the present invention that system  10  is controlled by a number of valves and maintained under negative pressure (in both the separator and collection chambers) to ensure that the return vacuum line remains free of contaminants. Additionally, the valve controls of the system allow for the collection chamber to be periodically isolated from the separator chamber to permit the discharge of collected waste material without needing to shut down the vacuum clean-out process within the separator chamber.  
         [0021]     Referring to  FIG. 1 , a first vacuum supply line  12 , as controlled by a first valve  14 , is used to draw the vacuum output from an associated application, such as any industrial application that utilizes a vacuum cleaning system. The vacuum output inevitably comprises fluids and/or debris that must be removed prior to recycling the vacuum flow back to the associated application. When first valve  14  is in the “open” position, the vacuum flowing along supply line  12  will be introduced through an input port  16  into a separator chamber  18 . The various valves depicted in the associated drawings are shown in outline form to define an “open” valve, and shown in darkened form to define a “closed” valve.  
         [0022]     In accordance with the teachings of the present invention, separator chamber  18  is formed to induce a cyclonic vacuum flow to efficiently remove the waste material from the vacuum. In this particular embodiment, separator chamber  18  is formed to include tapered walls, denoted by wall area  20  in  FIG. 1 . Therefore, when the vacuum flow enters separator chamber  18 , tapered walls  20  will divert the flow of the vacuum into a cyclonic form. Other cyclonic flow configurations may be used, one alternative arrangement being illustrated in the alternative embodiment of  FIG. 4 .  
         [0023]     Referring again to  FIG. 1 , as the vacuum input flow repeatedly circles within separator chamber  18 , liquid material and debris will be forced against tapered wall area  20 , and travel downward toward apex  22  of separator chamber  18 . While the liquid material and debris are drawn towards apex  22 , the filtered vacuum flow will be directed upward through an outlet port  24  and into a clean vacuum return line  26 . To further ensure that the filtered vacuum flow is completely free of contaminants, a filter element  28  may be disposed to surround outlet port  24  and trap any remaining particulate debris.  
         [0024]     In further accordance with the present invention, a second valve  30  is coupled to apex  22  of separator chamber  18  and is used to control the transfer of the accumulating liquid and debris into a connected collection chamber  32 . In operation, second valve  30  will normally remain “opened”, and only “close” when collection chamber  32  is full (determined in various ways, as described below). A third valve  34  is used to connect collection chamber to a vacuum line  36  that is coupled to clean vacuum return line  26  in the manner shown in  FIG. 1 . Vacuum line valve  34  is normally in the “open” position so that vacuum line  36  is coupled to collection chamber  32  and maintains a negative pressure within chamber  32 . The presence of the negative pressure within collection chamber  32  allows for the waste material to quickly and efficiently drain from separator chamber  18  into collection chamber  32 .  
         [0025]     In order to prevent the accumulating waste material from overfilling collection chamber  32  and contaminating the return vacuum being drawn through vacuum line  36 , a discharge process is periodically used to empty collection chamber  32 . It is a significant aspect of the present invention that this discharge process occurs without needing to shut down the vacuum line clean-out process within separation chamber  18 .  FIG. 2  illustrates system  10  during the discharge process, particularly illustrating the settings of the various valves used to control the isolation between chambers  18  and  32 . As shown, second valve  30  is actuated to close during the discharge process, isolating separator chamber  18  from collection chamber  32  while maintaining a vacuum (negative pressure) within separator chamber  18 . Vacuum line valve  34  is also closed to prevent the accumulated waste from entering the return vacuum line. A vent valve  33  is opened to release the negative pressure and/or apply a positive pressure within collection chamber  32 , and a drain valve  38  is opened to discharge the accumulated waste material from collection chamber  32 .  
         [0026]     Advantageously, the vacuum line clean-out process continues within separation chamber  18  uninterrupted while the discharge process is underway since the chambers have been isolated and a negative pressure is maintained in separator chamber  18 . Therefore, the inventive system may be periodically cleaned while not requiring the vacuum process itself to be shut down, realizing a significant savings in terms of time and expense.  
         [0027]     The discharge process may be manually controlled or provided under the control of a timer (for example, to initiate the discharge process every thirty minutes). Various other procedures for initiating and controlling the discharge process are possible and are considered to fall within the spirit and scope of the present invention.  
         [0028]     Indeed, as shown in  FIGS. 1 and 2 , one alternative method of controlling the discharge process in accordance with the present invention utilizes a high level sensor  40  disposed along the sidewall of collection chamber  32 . High level sensor  40  is utilized to monitor the rising level of liquid/debris as the vacuum system is in operation and trigger the initiation of the discharge process. Rather than sensing the “level” of the collecting liquid, other sensing arrangements may be used and are considered to fall within the scope of the present invention (for example, monitoring the weight of the collecting liquid). In any circumstance, however, sensor  40  is preferably configured to initiate the discharge process before the accumulating waste material nears the intake of vacuum line  36 , thus preventing the intrusion of any debris into the return vacuum flow.  
         [0029]     Additionally, as shown in  FIGS. 1 and 2 , an emergency shut-off sensor  42  may also be utilized in inventive system  10 . In particular, emergency shut-off sensor  42  is coupled to separation chamber  18  and utilized to shut down the entire system should there be a breakdown such that the waste material accumulates within separator chamber  18  to an undesirable or dangerous level. System  10  may further include a rinse application, periodically used to wash off the walls of separator chamber  18  and collection chamber  32 , to insure that all accumulated material is removed from the system. Referring to  FIG. 1 , one exemplary rinse application is shown as comprising a rinse water intake line  21 , controlled by a rinse valve  23  and a vent valve  25 . The rinse application is considered to improve the transport of the material through the system, where the rinse application may be controlled either manually or automatically, in a manner similar to the discharge process  
         [0030]      FIG. 3  illustrates an alternative embodiment of the present invention where a discharge analysis unit  44  is coupled to collection chamber  32  through drain valve  38 . In this embodiment, analysis unit  44  functions to sample and evaluate the liquid waste and contaminant debris. Various chemical and physical properties of the material may, for example, provide indications associated with the specific industrial application that would be useful in a feedback system to control the application. Alternatively, the specific properties of the waste material may be evaluated to determine the best disposal mechanism from an environmental point of view. The particular/specific uses of the waste analysis are considered to be ancillary to the subject matter of the present invention, which is directed to accumulating the waste material in a controlled fashion so that it can likewise be analyzed in a controlled system.  
         [0031]     It is to be understood that the clean-out and separator system of the present invention may also be utilized in a positive pressure environment instead of the negative pressure (vacuum) environment discussed above. A key aspect of the present invention is the automated, contained and isolated arrangement as shown in  FIGS. 1-3 , where the use of a separate collection chamber (maintained under essentially the same pressure as the separator chamber) allows for the removal and disposal of waste material without interrupting the clean-out process.  
         [0032]      FIG. 4  illustrates an alternative vacuum line clean-out system  50  formed in accordance with the present invention. As with the embodiment discussed above, system  50  includes a separator chamber  52  and a collection chamber  54 . An incoming vacuum line  56  from an industrial application (not shown) is controlled via a first valve  58  to enter separator chamber  52 . In accordance with this embodiment of the present invention, a separate diverter element  60  is disposed at the intake area of separator chamber  52  and functions to induce the cyclonic flow of the incoming vacuum stream. As with the embodiment described above, the cyclonic flow of the incoming vacuum flow will force the liquid and any particulate debris against the sidewalls  62  of separator chamber  52 , then fall towards the bottom thereof. The clean vacuum flow is drawn upward (e.g., through an opening  63  in diverter  60 ) into a clean vacuum return line  55  of system  50 . As with the arrangement described above, an additional filtering element  61  may be disposed along the outlet path to ensure that any particulate remaining in the vacuum flow is prevented from entering clean vacuum return line  55 .  
         [0033]     The accumulating liquid/debris thereafter drains into the connected collection chamber  54 . As with the embodiment described above, collection chamber  54  is maintained at essentially the same pressure as separator chamber  52  via a vacuum line  66  that is coupled to “clean” vacuum return line  55 .  
         [0034]     An in-situ sensing element  64  is shown in  FIG. 4  as disposed between separator chamber  52  and collection chamber  54 , and used to determine when a predetermined amount of debris has accumulated within collection chamber  54  and needs to be discharged. When collection chamber  54  is sufficiently “full” (as determined by sensing element  64 ), sensing element  64  closes the connection between separator chamber  52  and collection chamber  54 , isolating the vacuum clean-out process from collection chamber  54  and allowing the accumulated waste material to be removed from collection chamber  54 . As described above, a vent  66  is opened at collection chamber  54  to relieve the negative pressure and allow the waste to be discharged through a drain  68 . During discharge, separator chamber  52  remains under negative pressure (by virtue of being isolated from collection chamber  54 ) and continues to filter the incoming waste vacuum line and return a ‘clean’ vacuum flow to return line  55 .  
         [0035]     Again, system  50  may be configured in a manner similar to the previously-described embodiment, including the use of manual controls in place of in-situ sensing element  64 . Alternatively, a periodic discharge system may be employed that automatically drains the collected material in periodic time intervals. Regardless of the specific arrangement used to initiate the discharge procedure, it is a significant aspect of the present invention that the collection chamber is isolated from the separator chamber during discharge to allow for the vacuum line clean-out process to continue uninterrupted.  
         [0036]     While the invention has been described with regard to the preferred embodiments, it is to be understood by those skilled in the art that the invention is not limited thereof, and that changes and modifications may be made thereto without departing from the spirit and scope of the present invention as defined by the following claims.