Abstract:
A processor and method for treating infectious waste utilizes a processing chamber having an inlet for delivering processing water at an elevated temperature and under pressure into the processing chamber, an opening in the processing chamber for receiving of infectious waste and for removing treated waste, an agitator for opening the waste material to the action of the water at elevated temperature and pressure. A basket and/or a sieve may be carried in the processing chamber to facilitate drainage of spent processing water, and an apparatus may be included for removing neutralized waste through the opening in the processing chamber either by inverting the processor or by removing and inverting the basket and/or sieve.

Description:
TECHNICAL FIELD OF THE INVENTION  
       [0001]     This invention relates to a method useful for treating infectious waste as well as a system and processing apparatuses for carrying out the method.  
       BACKGROUND OF THE INVENTION  
       [0002]     Currently, medical and biological waste, generally referred to herein as “infectious waste,” generated in hospitals and other medical and research related facilities that contain disease-producing organisms or pathological wastes may be disposed through several disposal processes such as steam sterilization, microwave or plasma radiation, or incineration. These processes often require large expensive equipment and can pose environmental problems.  
         [0003]     Systems for using hot liquids to sterilize the infectious waste have also been developed. These systems employ large tanks wherein a pump for chopping and circulating the waste material through the system circuit is contained within the system. These systems required large quantities of fresh liquid that require a long period of time to heat to the desired processing temperature. Further, once the liquid is used to process the infectious waste, the liquid is disposed of. Before the system can be used again, the user must wait for the next batch of fresh process liquid to heated to the desired temperature. Such use of large quantities of liquid is costly not only in the use of the large quantity of liquid, but also through the large expenditure of energy needed to heat each batch of the liquid to the desired temperature.  
         [0004]     Another concern with these hot liquid systems is that the pumps used within the systems are industrial pumps having ridge blades that pulverize waste. The pumps are prone to clogging by flexible waste such as tubing and textile waste that wraps around the blades and are subject to damage by metal objects such as clamps, scalpel blade holders. Therefore, the pumps must be cleaned on a regular basis. Due to the construction of the system, these pumps are hard to access and clean. Further, when the pump inevitably fails, repair is difficult and dangerous because the pump and system are clogged with infectious waste. Further, due to the massive size of these systems it is nearly impossible to remove the system for off-site repair.  
         [0005]     Therefore, a need exists for a process and system for treating infectious waste that can increase the efficiency and safety of treating the waste.  
       SUMMARY OF THE INVENTION  
       [0006]     The present subject matter recognizes and addresses the above briefly discussed drawbacks, and others of above-described processes and systems for treating infectious waste. Accordingly, a general aspect of the present subject matter is to provide a process and a system, as well as different components of the system, that can increase the efficiency and safety of treating infectious waste. Additional aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.  
         [0007]     In an exemplary embodiment, a method for processing infectious waste is provided. Heated water is introduced under pressure into a processing chamber that contains infectious waste. The heated water should be at a temperature that biologically neutralizes the infectious waste. The infectious waste and the heated water are agitated through the action of an agitator to a point where the infectious waste is neutralized by the heated water. The temperature of the water is maintained at a temperature that biologically neutralizes the infectious waste at least until such neutralization occurs.  
         [0008]     The water is then forced from the processing chamber by a pressure differential. During the removal of the water, the water forced from the processing chamber is strained to keep the waste material within the processing chamber. As the water is removed, at least a portion of the water is recycled to be reused in processing further infectious waste. The neutralized waste is then cooled within the processing chamber before being removed from the processing chamber.  
         [0009]     To perform the above-described method, an exemplary embodiment of a system for processing infectious waste to neutralize the waste is provided. The system includes a processing chamber for receiving infectious waste and processing water that is at an elevated temperature sufficient to process said infectious waste. The processing chamber defines an opening through which to receive and remove the waste. A closure member is carried adjacent to the processing chamber. The closure member is positionable over the opening defined in the processing chamber so as to seal the processing chamber closed. Further, the closure member is removable from the opening of the processing chamber to permit receipt of the waste before processing and removal of the waste after the waste has been neutralized.  
         [0010]     A holding tank is connected to the processing chamber. The holding tank supplies the processing water at the elevated temperature sufficient to process the infectious waste in the processing chamber. A filter is disposed between the processing chamber and the holding tank. The filter cleans the processing water that exits the processing chamber and supplies at least a portion of the filtered processing water back to the holding tank to be reused in the processing chamber. In this manner, water can be recycled increasing the efficiency of the processing system.  
         [0011]     An exemplary embodiment of an apparatus for use in a system for processing infectious waste is also provided. The apparatus includes a processing chamber for receiving infectious waste and processing water that is at an elevated temperature sufficient to process the infectious waste. The processing chamber forms an opening through which to receive and remove the waste. A closure member is carried adjacent to said processing chamber. The closure member is positionable over the opening formed in the processing chamber so as to seal the processing chamber closed. Further, the closure member is removable from the opening of the processing chamber to permit receipt of the waste for processing and removal of the waste after said waste has been neutralized.  
         [0012]     An agitator extends within the processing chamber. The agitator has a rotatable internal shaft possessing an axis extending through the process chamber with a tapered blade carrier disposed on a free end of the shaft. A plurality of blades are pivoted about pivot points on the tapered blade carrier. The blades are spring-loaded and are biased upward parallel to the axis of the internal shaft at rest. Upon rotation of the shaft, centrifugal force causes the blades to extend outward from the blade carrier about the pivot points into an angular position as measured from the axis of the internal shaft. The agitator spins the blades within the processing chamber when the processing chamber is filled with heated water and infectious waste, thereby mixing the heated water and infectious waste thoroughly to biologically neutralize the infectious waste by rapidly exposing the waste to the heat in the water.  
         [0013]     An exemplary embodiment of a pressure sealable chamber closure member which is usable in the processing apparatus includes a lid with a rotatable hub located on the lid. A plurality of latch arms is connected to the hub on first ends of the latch arms. The hub is rotatable in a first direction so that the latch arms rotate causing a second end of each of the latch arms to latch the lid onto the processing chamber. When the hub is rotated in a second direction, the latch arms rotate causing the second end of each of the latch arms to unlatch the lid from the processing chamber.  
         [0014]     Within the processing chamber, an exemplary embodiment of a centrifugal agitator may include a rotatable internal shaft having a first end and a second end with an axis that extends vertically therethrough. A rotatable blade carrier is mounted on the first end of the shaft. The blade carrier has a surface tapering inwardly toward a free end of the blade carrier.  
         [0015]     A plurality of blades is pivotally connectable to the tapered blade carrier with the blades being spaced about the free end of the blade carrier. Springs are carried by the blade carrier and in communication with the blades and the blade carrier. The springs bias the blades upward about parallel to the axis of the internal shaft when the blades are in a resting position. The blades are then extendable upon rotation of the shaft to outward positions from the blade carrier about the pivot points as measured from the axis of the internal shaft due to centrifugal force. In this manner, the blades can interact with the processing water and waste without becoming immobilized by the waste.  
         [0016]     All the features of the subject matter will be described in greater detail through the use of the appended figures. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]     A full and enabling disclosure of the present invention, including the best mode thereof, to one of ordinary skill in the art is set forth more particularly in the remainder of the specification, including reference to the accompanying figures, in which:  
         [0018]      FIG. 1  is a schematic view illustrating an exemplary embodiment of a system for processing infectious waste in accordance with the present invention;  
         [0019]      FIG. 2  is a front perspective view illustrating an exemplary embodiment of an apparatus for processing infectious waste constructed in accordance with the present invention;  
         [0020]      FIG. 3  is a cross-sectional view of the processing chamber shown in  FIG. 2 ;  
         [0021]      FIG. 4  is a cross-sectional view illustrating a further exemplary embodiment of a processing chamber in accordance with the present invention;  
         [0022]      FIG. 5  is a cross-sectional view illustrating an exemplary embodiment of an agitator in accordance with the present invention;  
         [0023]      FIG. 6  is a top view illustrating a portion of a sieve in accordance with the present invention;  
         [0024]      FIG. 6A  is a cross-sectional view along lines I of the portion of the sieve as shown in  FIG. 6 ;  
         [0025]      FIG. 7A  is an elevation view illustrating an exemplary embodiment of a chamber closure member in accordance with the present invention;  
         [0026]      FIG. 7B  is a magnified view of section II of the chamber closure member of  FIG. 7 ;  
         [0027]      FIG. 8A  is a top view illustrating a hub and connecting arm of the chamber closure member of  FIG. 7 ;  
         [0028]      FIG. 8B  is a cross-sectional view illustrating the hub and connecting arm of  FIG. 8A ;  
         [0029]      FIG. 9A  is a top view of the chamber closure member of  FIG. 7  with the latch arms in a closed position;  
         [0030]      FIG. 9B  is a top view of the chamber closure member of  FIG. 7  with the latch arms in an opened position;  
         [0031]      FIG. 10  is a schematic side view illustrating an exemplary embodiment of a processing chamber and removal apparatus in accordance with the present invention;  
         [0032]      FIG. 11A  is a schematic side view illustrating another exemplary embodiment of a processing chamber and removal apparatus in accordance with the present invention; and  
         [0033]      FIG. 11B  is another schematic side view illustrating the processing chamber and removal apparatus shown in  FIG. 11A . 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0034]     Reference will now be made in detail to the presently preferred embodiments of the invention, one or more examples of which are shown in the figures. Each example is provided to explain the invention, and not as a limitation of the invention. In fact, features illustrated or described as part of one embodiment can be used with another embodiment to yield still a further embodiment. It is intended that the present invention cover such modifications and variations.  
         [0035]      FIG. 1  illustrates a system, generally  10 , for processing infectious waste to biologically neutralize the waste so that the waste may be safely discarded or recycled. The system  10  includes a processing chamber  20 , a holding tank  30 , a filter  40 , a transfer tank  50  and a heat exchanger  60  that are used to neutralize infectious waste using superheated water, while recycling at least a portion of the water to be reused again in the process. Thereby, efficiency of the processing of infectious waste can be increased and a savings in cost can be realized through the recycling of the heated water.  
         [0036]     In general, the infectious waste is placed into the processing chamber  20  and a closure member  38 , such as a lid, closes the processing chamber  20 . The holding tank  30  supplies superheated process water to the processing chamber  20  to sterilize, or neutralize, the infectious waste contained therein. Once the waste has been neutralized, the process water is run through a filter  40  into a transfer tank  50 . At least a portion of the filtered process water passes through transfer tank  50  and back into the holding tank  30 . The rest of the process water remains in the transfer tank  50  and is run through the heat exchanger  60  to transfer heat from the process water to new water being supplied to the holding tank  30 . The holding tank  50  is used to reheat the process water to a desired temperature for use in processing the next batch of infectious waste. A control and/or monitoring unit can be employed to control the system  10 .  
         [0037]     Before the system  10  can be used, water has to be introduced into the holding tank  30 . The water can be regular tap water supplied by a municipality. To initialize the system, a valve  14  opens to allow water from a supply of water  12  to flow through the heat exchanger  60  and into the holding tank  30 . Valve  16  opens to bypass the flow control valve  18  allowing a faster fill time. A vent valve  22  on top of the holding tank  30  opens to permit air to escape the holding tank  30  as the holding tank  30  fills. The size of the holding tank  30  may vary depending on the amount of waste to be processed which can be used to determine the amount of water needed to neutralize the waste and, in turn, designate the size of the processing chamber  20 . For example, the holding tank  30  may be a 60-gallon tank.  
         [0038]     When the level of water in the holding tank  30  reaches a first specified amount, a lower level sensor  24  activates a valve  26 , causing the valve  26  to open, allowing steam from a supply of steam  28  to enter a sparge pipe  32 , thereby heating the water as it enters the holding tank  30 . For a sixty-gallon holding tank, the first specified amount at which the lower level sensor  24  activates the valve  26  may be twenty gallons. Water continues to flow into the 60-gallon tank until the upper sensor is reached. An upper level sensor  36  is set at a second specified amount of water. When the second specified amount of water has filled the holding tank  30  and the upper level sensor  36  is reached, valve  14  and valve  16  are activated stopping the water flow. For a sixty-gallon holding tank, the second specified amount of water at which the upper level sensor activates the valve  14  and  16  to stop the water flow may be fifty gallons.  
         [0039]     A thermocouple  34  in the holding tank  30  monitors the water temperature. Valve  26  stays open allowing steam to continue to heat the water and vent valve  22  on the holding tank  30  stays open until the water temperature reaches approximately 212° F. for about a minute. This allows all of the air to escape the holding tank  30  and the remainder of the holding tank  30  is filled with steam. Valve  22  then closes and valve J stays open until the water reaches a desired temperature as the pressure in the holding tank  30  builds. Once the temperature reaches the desired level, the valve  26  closes. Valve  26  will reopen if the temperature falls below the desired level. The temperature should be high enough to neutralize the infectious waste. For example, a temperature of approximately 285° F. will more the adequately suffice. Steam pressure at 285 degrees F. is approximately 40 psig.  
         [0040]     Once the holding tank  30  is filled to the desired level and the water is raised to the proper temperature, the processing of waste can begin. Waste is loaded into the processing chamber  20  and the closure member  38  is closed. When the closure member  38  on the processing chamber  20  is closed and locked, valve  42  opens allowing water to flow from the holding tank  30  into the processing chamber  20 . The pressure in the holding tank  30  is greater than the pressure in the processing chamber  20 , so the water flows with a great deal of force. Valve  52  opens allowing air to escape the processing chamber  20  as the water flows from the holding tank  30  into the processing chamber  20 .  
         [0041]     A flow sensor  54  located at the bottom of the processing chamber  20  where the water flows into the chamber  20  senses that the flow of water stops after the second specified amount of water has entered the processing chamber  20 . The flow sensor  54  then activates valves  42  and  52  causing the valves  42  and  52  to close. As the water enters the processing chamber  20 , it heats the processing chamber  20  and the waste in the processing chamber  20  by giving up some of its energy to the chamber  20  and the waste.  
         [0042]     The temperature of the water will drop along with the pressure within the processing chamber  20 . A thermocouple  56  monitors the temperature within the processing chamber  20 . If the temperature drops below a specified level, then valve  58  opens allowing steam to sparge into the processing chamber  20  Thereby raising the pressure within the processing chamber  20  and raising the temperature back up to the desired processing temperature.  
         [0043]     For example, the temperature of the water may drop from 285° F. to approximately 255° F. and the pressure will drop to approximately 18 psig. If the temperature drops below 255°, then valve  58  opens allowing steam to sparge into the processing chamber raising the temperature back up to the desired processing temperature of 255° F. to 256° F.  
         [0044]     Shortly after the water has entered the processing chamber  20 , an agitator located in the bottom of the processing chamber  20  starts to spin. The agitator causes the superheated process water to mix with the infectious waste by opening bags in which the infectious waste is contained and facilitating the exposure of the waste to the superheated water. The temperature of the water thereby biologically neutralizes the waste.  
         [0045]     The waste should be exposed to the process water for a period of time long enough to neutralize the waste. At temperatures above 255° F., the processing time is approximately 10 minutes. When the necessary time has elapsed, the agitator stops, and the valves  62  and  64  open. Due to the pressure differential, the water then flows through the filter  40  and the transfer tank  50  back into the holding tank  60 . At this time, the holding tank  60  is empty and has cooled sufficiently so that the pressure is at or near zero. The vent valve  22  can be opened to assure zero pressure. The 18 psig in the processing chamber  20  forces the water back into the holding tank  30 .  
         [0046]     A flow sensor  78  near the bottom of the holding tank  30  senses when the flow of water stops and closes valves  62  and  64 . A portion of the water is retained in the transfer tank  50 . A check valve  66  at the entry of the transfer tank  50  prevents the back flow of water out of the transfer tank  50 . In this manner, only a part of the original process water is recycled back in the holding tank  30 . For example, when the system uses fifty gallons of process water, only forty gallons of the original 50 gallons of water is returned to a 60-gallon holding tank.  
         [0047]     Valve  14  opens allowing water from a supply of water  12  to flow through the heat exchanger  60  and into the holding tank  30 . A flow control valve  18  controls the flow of water from the supply of water  12  through the heat exchanger  60 . Normally, water from a municipality will flow at a rate of approximately two gallons per minute. Therefore, in an embodiment where ten gallons of water needs to be added to reach fifty gallons in the sixty-gallon tank, the water will be replenished in five minutes.  
         [0048]     At the same time valve  14  opens, valve  68  also opens allowing the water in the transfer tank  50  to flow through the opposite side of the heat exchanger  60 . Valve  70  controls the rate at which this water flows to approximately two gallons per minute for 5 minutes. The heat exchanger  60  is sized to remove a portion of the energy from the used water and return it to the fresh water as it flows into the holding tank  30 . At the same time that valves  14  and  68  open, valve  26  opens to permit steam to sparge into the holding tank  30  in order to bring the water in that holding tank  30  back up to the desired level. In the embodiment using a sixty gallon holding tank, this process takes approximately 10 minutes.  
         [0049]     Also, when valves  62  and  64  close, valve  74  opens momentarily to allow water from the supply of water  12  to spray from the top of the closure member  38  inside the processing chamber  20  in order to cool the waste inside the chamber  20 . At the same time, valve  72  at the base of the processing chamber opens to drain the water sprayed from valve  74  into the processing chamber  20 . When the waste has been cooled by the spray from the top of the processing chamber  20 , valve  74  closes. The cooling water flows through valve  72  to drain. When the cooling water has drained and the waste is cooled, the closure member  38  on the processing chamber  20  unlocks and the closure member  38  rises to its open position. At that time, the waste is removed from the processing chamber  20 . After the waste has been removed, the processing chamber  20  is ready to start the next processing cycle.  
         [0050]     By recycling and reusing the process water, water consumption is kept to a minimum. Reclaiming a large portion of energy from the process water that is drained and not recycled makes for an energy efficient system. At the same time, adding fresh water with each cycle keeps the process water from becoming fouled. The entire system  10  can be drained periodically and refilled to ensure the quality of the process water being used. To ensure the effectiveness of the filter  40 , the filter  40  may be cleaned periodically by back flushing the filter with a momentary burst of water by opening valve  76 .  
         [0051]     The systems  10  for processing infectious waste constructed in accordance with the invention are preferably controlled and monitored by a control system, such as conventional programmable logic controllers (“PLC”), such as suitable PLC&#39;s manufactured by Allen-Bradley, a division of Rockwell Automation based out of Milwaukee, Wis., central processing units (“CPU”), microcomputers, and the like. Through an appropriate set-up of the control system, the valves, agitators and/or closure members can be monitored and controlled separately or in communication with one another. Any conventional suitable control system or systems may be employed.  
         [0052]      FIGS. 2 through 11  illustrate different exemplary embodiments of the processing chambers and related components. In  FIGS. 2 and 3 , a processing chamber  120  that can be used in the exemplary system described above is provided for treating infectious waste. The processing chamber  120  includes walls  124  and a concave bottom  126 . At a top portion of the processing chamber  120 , an opening  122  is defined by the walls  124 . The opening  122  provides unobstructed access to the processing chamber  120  permitting loading of the infectious waste to be neutralized into the processing chamber  120 .  
         [0053]     The processing chamber  120  has a suitable housing  130  having a base  134  and access doors  132 . The housing  130  provides an insulative barrier around the processing chamber  120  to prevent injury to operators due to the temperatures the exterior of processing chamber  120  can reach. The access doors  132  provide access to the processing chamber  120  and other various components to allow activities such as maintenance to be performed. The housing  130  can be easily disassembled for major overhauls.  
         [0054]     A closure member, or lid,  138  is provided adjacent to the processing chamber  120  to sealably cover the opening  122  of the processing chamber  120 . The closure member  138  has a cover top  136  disposed thereon to serve as a cover for the housing  130 . The cover top  136  protects the operator from exposure to the temperatures which the closure member  138  can reach. The closure member  138  have seals along its rim  135  that hermetically seal the processing chamber  120  and closure member  138  when the pressure builds in the processing chamber from the superheated process water.  
         [0055]     As can be seen from the cut away at the bottom of the housing  130 , a line  128  is operably attached to the processing chamber  120  for providing the heated water from a holding tank in the system. The line  128  delivers heated water to the processing chamber  120  and thereafter drains the used water from the processing chamber  120 . An internal shaft  142  of an agitator  140  extends upward through the bottom  126  of the processing chamber  120 . The internal shaft  142  can be driven by a drive unit to spin the agitator  140  to thoroughly mix the process water supplied by line  126  with the infectious waste, thereby neutralizing the waste.  
         [0056]      FIG. 3  shows a cross-sectional view of the processing chamber to better illustrate the relationship of the agitator  140  to the processing chamber  120 . The agitator  140  of this exemplary embodiment is a centrifugal agitator that is located in the bottom  126  of the processing chamber  120  below a water line that the process water will reach when processing the infectious waste. An axis  139  of the agitator is in line with the axis of the processing chamber  120 . The agitator  140  has a plurality of blades  150  disposed on a free end  149  of the agitator  140 . As the internal shaft  142  is rotated, the blades  150  are extended by centrifugal force in a direction F 2  from a resting position  156  to an extended position  158 . The process water within the processing chamber  120  is stirred up by the rotating agitator blades  150  along with the waste that has been placed in the processing chamber  120 .  
         [0057]     The placement of the agitator within the processing chamber is not critical, as long as it allows for proper circulation of the heated water and allows for removal of the waste from the processing chamber. Further, multiple agitators can be employed within a processing chamber to increase the circulation of the waste and heated water in some embodiments.  
         [0058]     As can be seen from  FIGS. 3 and 5 , the internal shaft  142  of the agitator  140  extends vertically through the bottom of the processing chamber  120  and up through a stationary lower agitator housing  148  and a stationary upper agitator housing  146 . The internal shaft  142  is mounted in ball bearings  143  that permit the internal shaft  142  to rotate within the upper agitator housing  146  and the lower agitator housing  148 . Due to the environment in which the agitator  140  operates, the internal shaft  142  is protected with a labyrinth seal  155  and interior seals  157  to prevent fluid from the processing chamber  120  from leaking into the bearings  143  and further, from leaking outside the processing chamber  120 .  
         [0059]     The internal shaft  142  is connected to a rotating tapered blade carrier  144 . The blades  150  of the agitator  140  are affixed to the tapered blade carrier  144 . The blades  150  are attached to the tapered blade carrier  144  so that the blades  150  pivot at the tapered blade carrier  144  about blade pin pivot points  152 . The blades  150  are spring-loaded via torsion springs  154  so that, when not turning, the blades  150  reside in an upward resting position  156 . By having the blades  150  biased upwards in a resting position when the agitator is at rest, better permits removal of the neutralized waste from the processing chamber  120 .  
         [0060]     The agitator blades  150  and the tapered blade carrier  144  are secured to the internal shaft  142  via a retaining cap  153 . The retaining cap  153  can be secured to the internal shaft  142  by screwing the cap  153  into the internal shaft  142  and thereby holding the taper blade carrier  144  to the internal shaft  142  as shown in the illustrated embodiment. The retaining cap  153  may have a threaded member  151  that is inserted through an aperture  145  in the blade carrier  144 . The threaded member can then be screwed into a threaded aperture  141  in the top of the internal shaft  142 . It may be preferable that the retaining cap be screwed into the threaded aperture  141  in a reverse direction to the direction in which the internal shaft  142  spins. The retaining cap used in the agitator  140  may employ some other conventional method to secure the tapered blade carrier  144  to the internal shaft  142  such as an adhesive bonding or a mechanical spring latch.  
         [0061]     To rotate the internal shaft  142  and thus the blades  150 , the bottom of the internal shaft  142  is connected to a drive unit. The drive unit may be any conventionally known drive system. For example, the dive unit may be a motor that drives a belt and pulley system. In such an example, the motor may turn a belt that in turn rotates the internal shaft  142  in a direction F 1  as shown in  FIG. 5 . The internal shaft  142  may also be rotated in a direction counter to direction F 1 .  
         [0062]     As the motor spins the internal shaft  142 , the tapered blade carrier  144  also spins, and as the tapered blade carrier spins, centrifugal force causes the agitator blades  150  to extend to an outward position  158  into the processing chamber  120 . When the agitator blades  150  are fully extended, they remain tilted upward at the free ends  159  so that the ends  159  of the agitator blades  150  are higher than the blade pin pivot point  152  on the tapered blade carrier  144 . These outwardly spinning agitator blades  150  cause the water in the processing chamber  120  to churn and bring the infectious waste contents of the processing chamber  120  into contact with the spinning blades  150 .  
         [0063]     Infectious waste is generally bagged in plastic bags, and as such, will be put into the processing chamber while still in the plastic bags. Much of the waste contained in the plastic bags is plastic tubing, plastic and textile bandages and wound treatment material and paper products. However, the waste often also contains syringes, lancets, and other disposable medical instruments or devices. When these bags come in contact with the spinning agitator blades  150 , the agitator blades  150  rip open the bags and expose the infectious waste contents of the bags to the superheated process water in the processing chamber  120 . At the same time, the fast rotating blades  150  strike the plastic tubing, paper products and plastic and textile wound treatment material, breaking and tearing this waste into small pieces and strands.  
         [0064]     The dissevered infectious waste comprising the stringy textile material, plastic tubing and bags torn apart by the blades  150  has a tendency to wrap around the tapered blade carrier  144  and agitator blades  150 . The waste tends just to wrap around the taper blade carrier  144  and not the stationary upper and agitator housings  148 ,  149  due to the rotation of the tapered blade carrier  144 . The tapered blade carrier  144  is tapered toward the free end  149 . The angle of the taper is such that the pressure generated by the wrapping of material causes the resultant force to push the material upward.  
         [0065]     When the wrapping of waste material generates sufficient force about the tapered blade carrier  144 , the wrapped waste material then pushes upward against the agitator blades  150 . Since the blade pin pivot points  152  of the agitator blades  150  are lower than the blade ends  159 , when the force of the wrapped material overcomes the centrifugal force that extends the agitator blades  150  into outward positions  158 , the agitator blades  150  momentarily retract by pivoting about the blade pin pivot points  152  toward resting blade position  156 . This momentary retraction causes the wrapped material to dislodge and sling upward and off of the agitator blades  150 . As soon as the wrapped waste slings off, the agitator blades  150  again pivot to outward position  158 . To facilitate the dislodging and slinging off of the wrapped material, the agitator blades  150  are also tapered from their pivot point  152  toward the free ends  159  so that the agitator blades  150  are smaller at their extreme ends.  
         [0066]     In this manner, the waste being neutralized can be lessened in volume, while preventing the agitator  140  from being immobilized or rendered inoperable for its intended duty by the waste being neutralized. The blades  150  should be sturdy enough to withstand contact with syringes, lancets or some other hard medical devices disposed in a bag in the processing chamber  120 . The flexibility provided by spring loading the blades  150  allows for the blades  150  to be deflected upward if a hard piece waste such as a disposable medical device comes in contact with one of the blades  150 . Through an appropriate set-up of a control system as described above, the agitator  140  can be monitored and controlled. Any conventional suitable control system or systems may be employed.  
         [0067]     In an exemplary embodiment, a sieve apparatus may be provided within the processing chamber to prevent the waste that has been neutralized from flow with the process water back through system. As shown in  FIGS. 3 , a sieve apparatus  160  is provided in the processing chamber  120 . The sieve apparatus  160  is a sieve basket  162 . The sieve basket  162  fits inside the processing chamber  120  and is equipped with elastomeric seals  170  to seal the sieve/processing chamber interface. The seals  170  help to contain the waste inside the sieve basket  162  and aid in preventing waste material from exiting the processing chamber  120  through the line  128 . The sieve basket  162  is also preferably constructed with an opening  164  in the bottom  168  of the sieve basket  162  to permit the agitator  140  to extend through the bottom  168  of the sieve basket  162 . The opening  164  has a seal  172  around the edges of the opening  164 . The seal  172  interacts with the agitator  140  to prevent waste from exiting through the opening  164  during processing and when the process water is being drained through line  128 .  
         [0068]     The sieve apparatus  160  in the form of the sieve basket  162  define sieve holes  176  as shown in sieve section  174  in the  FIG. 6 . The sieve holes  176  allow the process water to enter through the sieve apparatus  160  so that infectious waste contained by the sieve apparatus  160  can be neutralized. Further, the sieve holes  176  permit the process water to drain from the sieve apparatus  160  while containing the waste within the sieve apparatus  160  and the processing chamber  120 .  
         [0069]     Due to the spinning of the agitator blades  150 , the processed waste often includes fibrous waste material from the shredded waste. It has been found if the sieve holes are too large, the space that separates the holes catches the fibrous waste material near the middle of the waste, the ends of the fibrous waste material pass through the sieve holes and become entangled on the backside of the sieve apparatus. Once the waste becomes entangled in this manner, it is very difficult and time consuming to remove from the sieve apparatus. Once enough fibrous waste material has entangled in this manner, the flow of water will almost completely stop, adversely affecting the neutralization process time.  
         [0070]     It is thus advantageous for the sieve holes  176  to contain the processed fibrous waste material by allowing process water to pass through the sieve, while also rendering the portion of any fibrous material that passes through the sieve holes  176  too short to become entangled on the backside of the sieve apparatus. This may be accomplished by having sieve holes  176  with an appropriate diameter and spaced at an appropriate distance  178 . For example, the sieve holes  176  may have sizes from about 0.020 inch diameter to about 0.078 inch diameter that are spaced from about 0.040 inches apart to about 0.125 inches apart. In some embodiments, it may be preferable to have sieve hole sizes of 0.033 inches in diameter and spaced at distances of 0.055 inches. By employing sieve holes  176  sized at such diameters and spaced at such distances  178 , fibrous waste material will lie across the inner surface of the sieve apparatus and will fall away from the sieve apparatus when the sieve apparatus is emptied.  
         [0071]     The sieve basket  162  possesses loops  166  to aid in the loading of the waste into the processing chamber  120  and unloading of the waste from processing chamber  120 . In the exemplary embodiment shown in  FIGS. 2 and 3 , a removal apparatus  180  is provided to load and remove the waste from the processing chamber. The removal apparatus  180  is a hoist  182  having a hooking device  186  that is extendable and retractable from a hoist arm  188 . The hooking device  186  form hooking arms  184  that are insertable into the loops  166  of the sieve basket  162 . Once the hooking arms are inserted into the loops  166 , the sieve basket  162  can be lifted into or removed from the processing chamber  120 . Due to the upward resting position  156  of the blades  150  of the agitator  140 , the sieve basket  162  can easily be removed and returned to its position in the processing chamber  220  without interference from the agitator  140 . The hoist arm  188  can be rotated about the hoist support  189 . The hoist  182  can thereby facilitate the insertion and extraction of the sieve basket  162  before and after processing.  
         [0072]     In this manner, the sieve basket  162  can be loaded with infectious waste and then can be inserted into the processing chamber  120 , while the sieve basket  162  can then be removed from the processing chamber  120  for dumping or removal of the neutralized waste. The loading of the sieve basket  162  can be done manually or through automation. For example, the sieve basket  162  may be loaded by dumping a container carrying the infectious waste into the sieve basket  162  while the sieve basket  162  is in the processing chamber  120  or while it is outside of the processing chamber  120 . After the processing of the waste, the sieve basket  162  can be removed from the processing chamber  120  by the hoist  182  and then automatically dump the neutralized waste onto a conveyor belt or into a container for disposal by inverting the sieve basket  162 . In this manner, operator contact with the contents of the sieve basket  162  is eliminated. When the sieve basket  162  has been repositioned in the processing chamber  120 , the processing chamber is ready for the next cycle.  
         [0073]      FIG. 4  shows a further embodiment of a processing chamber  220 . This processing chamber  220  has a concave bottom  226  surrounded by walls  224  and employs a different sieve apparatus  260 . The processing chamber  220  is equipped with an integral sieve  262  serving as the sieve apparatus  260 . The integral sieve  262  is placed above the concave bottom  226  of the processing chamber  220 , and is equipped with elastomeric seals  270  to seal the sieve/processing chamber interface. The exemplary integral sieve  262 , as with the sieve basket described above, is constructed with an opening  264  to permit the agitator  140  to extend through the integral sieve  262 . The opening  264  has a seal  272  around the edges of the opening  264 . The seal  272  interacts with the agitator  140  to prevent waste from exiting through the opening  264  during processing and when the process water is being drained through line  228 .  
         [0074]     The purpose of the integral sieve  262  is the same as the sieve basket  162 . The integral sieve  262  allows the process water to drain out of the processing chamber  220  while keeping the neutralized solid waste products in the processing chamber  220 . However, the processing chamber  220  is unloaded in a different manner. Instead of removing the waste by removing the sieve apparatus  260 , the sieve apparatus  260  remains in place while processing chamber  220  can be tilted or inverted along an axis to dump the waste contents out through the opening  222  into a desired container or onto a conveyor system to dispose of the waste.  
         [0075]     A different removal apparatuses may be used to invert processing chambers, like processing chamber  220 . The removal apparatus used to invert the processing chamber may be a manual apparatus or an automated apparatus. The removal apparatus may also incorporate a mechanism to aid in loading the processing chamber.  
         [0076]     For example, in the exemplary embodiment shown in  FIG. 7 , a processing chamber  320  that can be manually inverted is schematically illustrated. Such a processing chamber would be a small processing chamber used in doctor offices, clinics, or other places where a minimal amount of medical/bio waste is created on a daily basis. The processing chamber  320  is attached to a removal apparatus  380 . The removal apparatus  380  in the form of a rotation unit  382  includes chamber supports  325  on either side of the processing chamber  320  with each support  325  having an aperture through which a rotating member  332 . The rotating members  332  are secured to the processing chamber  320  and rotate on within the supports  325  about an axis  386 .  
         [0077]     The process water supply line and the steam supply line (not shown) pass through the rotating member  332  through the use of rotary couplings as shown in  FIG. 1 . The pipes that extend outward from the rotating members  332  on the rotating member side of the rotary couplings and feed the steam and process water to the processing chamber  320  rotate with the processing chamber  320 . In this manner, the process water and steam can be fed into the processing chamber  320  from the bottom, while still permitting the processing chamber to rotate about the axis  386 . At least one handle  384  is connected to at least one rotating member  332  to allow rotation of the processing chamber  320  to an inverted position  320 ′.  
         [0078]     To process the waste, a closure member  338  is positioned in an open position  338 ′ and the waste to be treated is placed in the processing chamber  320  on top of an integral sieve as described above. The closure member  338  is then placed in a closed position along a rim  318  of the process chamber  320 . The process water and steam, as needed, pass through the water and steam supply lines into the processing chamber  320 . An agitator as described above thoroughly mixes the process water and the waste thereby neutralizing the waste.  
         [0079]     Once the waste in neutralized and the process water is drained from the processing chamber  320 , the closure member is reopened to the position  338 ′. The handles  384  can then be used to rotate the processing chamber  320  into an inverted position  320 ′ to dump the neutralized waste into a container  330  for disposal. After the waste is removed from the processing chamber  320  in this manner, it may be rotated back to the processing position to start the process again.  
         [0080]     In this manner, a light weight processing chamber which uses less superheated process water and processes less waste can be manually loaded and unloaded. A system employing the processing chamber  380  allows an expensive alternative to larger system which require mechanical assisted or automated loading and unloading for institutions that create a limited amount of bio waste. Other manual features of this smaller machine may include the manual opening and closing of the closure member  338 .  
         [0081]     In a different exemplary embodiment, as shown in  FIGS. 11A and 11B , a processing chamber  420  may be loaded and unloaded automatically. Such processing chamber  420  can be employed in larger institutions such as hospitals, which create a large amount of medical and bio waste on a daily basis. The processing chamber  420  is positioned in and operably connected to a removal apparatus  480 . The removal apparatus  480  is an automated rotation unit  482  that mechanically rotates the processing chamber  420  about an axis  486 . For example, the rotation unit may employ a hydraulic system to rotate the processing chamber  420 . As with the manual inverting removal apparatus described above, the process water supply line and the steam supply line (not shown) are connected to the process water pipe and steam pipe (not shown) that feed into the processing chamber  420  by rotary couplings to allow the process water pipe and steam pipe to rotate with the processing chamber  420 .  
         [0082]     To process the waste in the processing chamber  420 , a container, or bin,  450  containing bagged infectious waste is placed on a scales platform  460  and weighed to determined the amount of bagged infectious waste to be placed in the processing chamber  420 . Upon the determination of the weight of the waste, a delivery arm  488  lifts the container  450  from the scale platform  460  in front of the processing chamber  420  and rotates it toward the processing chamber  420 . At the same time or at some point earlier, the rotation unit  482  rotates the processing chamber from a processing position to a receiving position  420 ′. The delivery arm  488  rotates the container  450  to a dumping position  450 ′ where the waste contents within the container  450  are dumped into the processing chamber  420  in the receiving position  420 ′. To facilitate loading, a rotation unit  482  is capable of rotating the processing chamber  520  45° to the receiving position  420 ′, and rotating the container  450  135° to the dumping position  450 ′ to load the contents of the container  450  into the processing chamber  520 .  
         [0083]     Once the delivery arm  488  returns the container  450  back to the scales platform  460  and the processing chamber  420  is rotated back to the upright processing position, a closure member  438  is lowered into a closed position against the process chamber  420 . The process water and steam, as needed, pass through the water and steam supply lines and pipes into the processing chamber  420 . An agitator  440  is rotated by a drive unit  441  to thoroughly mix the process water and the waste thereby neutralizing the waste. As with the process water and steam pipes, the drive unit  441  rotates with the processing chamber  420  about the axis  486 .  
         [0084]     Once the waste in neutralized, the process water is drained from the processing chamber  420  while an integral sieve as described above retains the processed waste within the processing chamber  420 . The closure member  438  can then be reopened. The closure member should be raised far enough above the processing chamber  420  to allow the rotation unit  482  to rotate the processing chamber  420  to an ejection position  420 ″. In this position  420 ″, the waste is dumped from the processing chamber  420  onto a conveyor belt  492  of a conveyor system  490 . The conveyor system  490  was walls  494  to help keep the waste on the conveyor belt. The waste material is then carried by the conveyor system  490  to an on-site shredder and/or compactor before being removed from the facility.  
         [0085]     Through an appropriate set-up of a control system as described above, the removal apparatus  180 ,  380 ,  480  can be monitored and controlled. Any conventional suitable control system or systems may be employed.  
         [0086]     The processing chambers are equipped with a chamber closure members, or tops, that hermetically seal the unobstructed openings in the processing chambers to allow pressure to build within the processing chambers without allowing the pressure to escape. These closure members can be of different construction, depending on the size and type of processing chambers. Further, different types of latching systems may be used to secure the closure member to the processing chamber.  
         [0087]      FIGS. 7, 7B ,  8 A,  8 B,  9 A and  9 B illustrate an exemplary embodiment of a closure member  538  which is used to seal the processing chamber  520 . The closure member  538  includes a lid  537  is lowered onto the processing chamber  520  and secured into position against a chamber flange  518  of the processing chamber  520  by a latching system  525  positioned on the lid  537 . In the exemplary embodiment, the latching system  525  includes a rotatable multi-fingered hub  530  connected to latch arms  540  by connecting rods  550 . The multi-fingered hub  530  may be rotated in a first direction to cause the latch arms  540  to secure the closure member  538  to the processing chamber  520  and may be rotated in a second direction to release the latch arms  540  and the closure member from the processing chamber  520 .  
         [0088]     The multi-fingered hub  530  is centrally located on the lid  537  of the closure member  538 . The lid  537  of the closure member  538  has a rim  516  around its lower edge which is contactable with the chamber flange  518  around the opening at the top of the walls  524  of the processing chamber  520 . The rim  516  has mounting brackets  542  mounted thereto. Each of the latch arms  540  is pivotally connected to a corresponding mounting bracket  542  by a pivot pin  545 , which is positioned through alignable apertures in both the mounting brackets and the latch arms  540 .  
         [0089]     A connecting rod is run between the multi-fingered hub  538  and each latch arm  540 . At one end of the connecting rods  550  as shown in  FIGS. 8A and 8B , the connecting rods  550  each include a rod body  553 , a ball rod end  562  and a rod end  554 . Each connecting rod  550  is attached to the multi-fingered hub  530  by a corresponding ball rod end  562  with a bolt  563  and nut  561 . Each finger  529  of the multi-fingered hub  530  defines a receiving aperture  531  through which the bolt  563  of the ball rod end  562  passes. The nut  561  is tightened onto the bolt  563  of the ball rod end  562  on the opposite side of the finger  529  of the multi-fingered hub  530 . The ball rod end  562  is rotatable about the bolt  563 .  
         [0090]     At the opposing end of the connecting rods  550  as shown  FIGS. 7B, 8A , and  8 B, the connecting rods  550  are attached to the latch arms  540  by a rod ends  554 . The rod ends  554  are connected to a swivel brackets, or clevises,  552  by pins  556  that are secured by cotter pins  557 . The swivel brackets  552  allow the rod ends  554  to rotate about the pins  556 . Each swivel bracket  552  is, in turn, connected to a corresponding latch arm  540  by a pin  548 . The body  553  of each connecting-rod  550  has a threaded hole  551 ,  568  at each end  558 ,  566 . The rod ends  554  have right-handed threads  555  which allow the rod ends  554  to be screwable into the threaded holes  551  at the latch end  558  of the body  553  of the connecting rods  550 . Conversely, the ball rod ends  562  have left-handed threads  564 , which allow the ball rod ends  562  to be screwable into the threaded holes  568  at the hub end  566  of the body  553  of the connecting rods  550 . In this manner, the length of the connecting rods  550  can be adjusted. In particular, by rotating the body  553  in one direction or the other, the connecting rod  550  may be lengthened or shortened due to the orientation of the threads  555 ,  564  on the respective ball rod end  563  and rod end  554 . Other conventional methods and configurations may also be used to make the lengths of the connecting rods  550  adjustable.  
         [0091]     Different drive mechanisms can be used to rotate the multi-fingered hub  525 , for example a hydraulic drive system. In the exemplary embodiment, a hydraulic cylinder  534 , which is operated in a conventional manner by a hydraulic system, is attached to a support arm  535  to stabilize the cylinder  534 . The piston arm  536  of the cylinder  534  with a cylinder bracket  533  on its free end is connected to a hub lever  532  by the cylinder bracket  533 . The hub lever  532  is attached to the multi-fingered hub  530 .  
         [0092]     When the piston arm  536  of the cylinder  534  is in a retracted position as shown in  FIGS. 7 and 9 A, the closure member  538  is in a closed and sealed position against the chamber flanges  518  of the processing chamber  520 . In the closed position, each of the connecting rods is in an aligned position  550 ′ in line with the corresponding latch arm  540 . The latch arms  540  have been rotated about the mounting brackets  542  at the axes  544  so that rollers  546  held at the ends of the latch arms  540  distal from the end carrying the swivel bracket  552  reside under the chamber flange  518  of the processing chamber  520 .  
         [0093]     As the piston arm  536  is extended from the cylinder, the hub lever  532  rotates the hub  530  about the hub axis  528  in a direction V 1 . The rotating hub  530  pulls the connecting rods  550  in the direction the hub  530  is rotating. As the connecting rods  550  are pulled, the swivel brackets  552  pull on the latch arms  540  causing them to rotate upward about the mounting brackets at the axes  544 . In this manner, the rollers  546  dislodge from under the chamber flange  518  and the latch arms  540  are raised as shown in  FIG. 9B . The closure member  538  can then be lifted from the processing chamber  520 .  
         [0094]     In the opened position of the closure member  538  as shown in  FIG. 9B , each of the connecting rods are in a slanted position  550 ″ in line with the corresponding latch arm  540 . The latch arms  540  have been rotated about the mounting brackets  542  at the axes  544  so that the end of the latch arms  554  carrying the rollers  546  are extended in an outward position.  
         [0095]     Once the processing chamber  520  is loaded again and it is ready to be closed, the closure member  538  is placed in a closed position and the latch system  525  is activated again. As the piston arm  536  is retracted back into the cylinder  534 , the hub lever  532  rotates the hub  530  in a direction V 2 . The connecting rods  550  are pushed from the slanting position  550 ″ to the aligned position  550 ′. As the connecting rods  550  are pushed, the swivel brackets  552  push the latch arms  540  causing them to rotate downward about the mounting brackets at the axes  544 . In this manner, the rollers  546  roll under the chamber flange  518  and the latch arms  540  are placed in a closed position as shown in  FIGS. 7 and 9 A.  
         [0096]     A seal is carried in the closure member  538  that interacts with the processing chamber  520  to ensure the pressurized closing of the processing chamber  520 . The seal can be designed to increase its sealing effective as the pressure builds in the processing chamber  520 . In such a manner, the closure member  538  and latching system  525  can hermetically seal the processing chamber  520 .  
         [0097]     The chamber flange  518  may define a slightly raised portion on the bottom of chamber flange  518 . As the rollers  546  on the latch arms  540  move under the chamber flange  518  on the processing chamber  520 , the rollers  546  travel over the slight raised portion on the bottom of the chamber flange  58 . As pressure builds in the processing chamber  520 , the closure member  538  is pushed upward by the pressure, which makes it more difficult for the rollers  56  to travel back over the raised portion on the bottom of the chamber flange  518 . The sealing member that prevents leakage between the processing chamber  520  and the closure member  538  may be a lip type, with the lip pointed inward so that as pressure builds in the processing chamber  520 , the pressure on the seal exerts more force on the chamber flange  518 . Such a construction also allows for a slight upward movement of the closure member  538  without causing a leak and locks the rollers  546  on the latch arm  540  in place.  
         [0098]     The number of latch arms  540  used in the latch system  525  may vary. However, it is preferable that at least two latch arms are employed to facilitate sealing of the closure member  538  to the processing chamber  520 .  
         [0099]     The latching system  525  creates an “over-the-center” type fastening between the closure member  538  and the processing chamber  520 . The aligning of the fingers  529  of the hub  530 , the connecting rods  550  and the latch arms  554  when the connecting rods are in the aligned position  550 ′ in the closed position of the latching system  525  creates a more stable fastening of the closure member  538  to the processing chamber  520 . Simultaneously, the alignment of each of the latch arms  554  so that the corresponding swivel brackets  552 , axes  544  and the rollers  546  are at least proximally in a straight line also creates a more stable fastening of the closure member  538  to the processing chamber  520 .  
         [0100]     Through an appropriate set-up of a control system as described above, the closure member  38 ,  138 ,  338   438 ,  538  and/or latch system  525  can be monitored and controlled. Any conventional suitable control system or systems may be employed.  
         [0101]     It would be appreciated by those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope of the invention. It is intended that the present invention include such modifications and variations as come within the scope of the appending claims and their equivalents.