Abstract:
The invention relates to a control system for processing waste. The system controls pressure and temperature in a treatment vessel to provide a more efficient process. A system for shredding the waste in the vessel is used to improve process efficiency and provides a more compact waste product.

Description:
RELATED APPLICATION(S) 
     This application is a Continuation-In-Part of U.S. patent application Ser. No. 08/924,614 filed on Sep. 5, 1997 now U.S. Pat. No. 6,139,793, the entire teachings of which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Studies conducted in hospitals in the United States and Canada indicate that about 1.5 to 7.5 kg of biomedical waste is generated per bed per day (Ontario Ministry of the Environment “Biomedical Waste Incinerators” Incinerator Design and Operating Criteria Vol. II, October, 1986). Biomedical waste includes used syringes, gowns, bedding, containers, bandages, dressings, used disposable gloves, human waste and other liquid and solid waste materials which may be contaminated with, for example, infectious bacteria and viruses. 
     Incineration is presently a method of treating the biomedical waste. There are, however, concerns about the environmental impact of incineration, especially with respect to airborne emissions from incineration plants. Accordingly, incinerators must now be equipped with sophisticated emission quality control devices. Such devices are expensive, thereby providing a financial obstacle to the upgrading and/or building of incinerators. 
     Alternatives to incineration include autoclaves, chemical treatment, microwave and microwave technologies. The most common alternative, is sterilization by steam in an autoclave. The process uses hot steam under pressure to kill bacteria, viruses, parasites and heat-resistant spores and is used extensively in a non-waste treatment manner in laboratories to sterilize equipment, media for bacterial growth and pathogenic cultures. 
     Sterilization of biomedical waste is achieved by exposing all portions of the waste to a temperature and pressure for a time sufficient to kill bacteria, viruses, parasites and heat-resistant spores. However, since biomedical waste is segregated and packaged in leak-proof, color designed plastic bags (red is the designated color in the United States and yellow is the designated colour in Canada) contained in sealed boxes, heat transfer must often be effected through tightly wrapped packages and plastic bags containing the waste material. The sterilization cycle must then be extended to ensure that all portions of the waste material have been subjected to the desired conditions of temperature and pressure for the appropriate length of time. Accordingly, the time required to achieve sterilization depends on the efficiency of heat transfer which in turn depends on the type of material, density of the material, batch volume and how full the autoclave is loaded. Heat transfer is even further inhibited by entrained air inside the package resulting in cold spots which can interfere with sterilization unless the cycle is sufficiently extended to ensure complete sterility. 
     Another difficulty is the inability to control internal pressure of the sealed bags and boxes. In particular, bags and packages can explode during the process inside the vessel, making unloading very messy despite the elimination of infectious hazards. The degree to which the contents of the autoclave will explode is somewhat dependent on the length of the cooling cycle after the desired sterilization cycle. This cooling cycle can extend the time in the autoclave by 100% or more. 
     Sterilization in an autoclave relies on injection of steam directly into the autoclave. Injected steam condenses on the walls of the autoclave and on the outer surfaces of the waste and containers thereof or is absorbed by the waste. The steam condensate is then drained from the autoclave for subsequent disposal. It will be appreciated by those skilled in the art that the steam condensate is generally unsuitable for reuse and represents a significant energy loss as the hot water is drained. Furthermore, the moisture absorbed by the waste can substantially increase the weight of the packages, for example, by about 50%. Accordingly, the moist packages are heavier, more difficult to handle and make unloading cumbersome. Moreover, since dumping costs at landfill sites are typically set on a per ton basis, the increased weight due to moisture retention represents substantial increases in dumping costs. 
     An alternative to conventional autoclaves is a process for the disposal of medical waste in a pressure vessel fitted with high-speed blades. The blades are provided at the base of the vessel and operate at high rotational speeds (900-3500 rpm). An internal mixer is provided on the lid to direct the waste towards the blades. Steam is injected directly into the vessel for heat transfer. At the end of the sterilization process, the vessel is vented to vacuum to flash off moisture. 
     Another alternative to the conventional autoclave, is a cylindrical pressure vessel with an elongated cylindrical drum located in the pressure vessel for receiving the waste to be treated. The pressure vessel and the drum are set at an angle, such that the end where the drum is open and the door of the pressure vessel is located is elevated relative to the other end. The drum has a series of lifting paddles on the wall for agitation of the waste material in the drum as the drum is rotated within the pressure vessel. In addition, the drum has a helical flight which work in a counter-current manner with the lifting paddles to mix the waste and when the drum is rotated in the other direction moves the waste out of the drum for removal through the door of the pressure vessel. Water is added to the waste to attempt to receive a content of 75% moisture in the waste. Steam is injected directly into the pressure vessel for heat transfer. 
     SUMMARY OF THE INVENTION 
     A preferred embodiment of the invention relates to a control system for a waste treatment processing apparatus. The control system provides a computer automated system that controls operation of the process including the values, monitors pressure and/or temperature, speed and other parameters to increase capacity and improve operating efficiency. The system also records data relating to each processing cycle. 
     The invention further includes a cutting system to shred the contents during operation. This improves heat transfer to the waste, produces a more compact product and is better suited for recycling of waste product. 
     In the preferred embodiment the waste does not need to be pre-treated prior to being placed in the pressure vessel. Moisture in the form of water or steam does not need to be added to the pressure vessel for it to work efficiently in most waste composition make-ups. The waste is dried after sterilization to reduce both volume and the weight of the treated waste, therein making it more cost effective for disposal. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. 
     FIG. 1 is a schematic drawing of a process of the present invention; 
     FIG. 2 is a schematic drawing of a material flow in a treatment facility equipped to carry out the process of the present invention; 
     FIG. 3 is a schematic of a processing apparatus according to the invention; 
     FIG. 4 is a side view of a pressure vessel according to the invention with portions shown in section; 
     FIG. 5 is an enlarged view of the temperature sensor; 
     FIG. 6 is an end view of the pressure vessel with a portion broken away showing the interior including paddles; 
     FIG. 7 is an enlarged view of a paddle interacting with the wall of the pressure vessel taken along line  7 — 7  of FIG. 6; 
     FIG. 8 is a perspective view of a paddle interacting with the wall of the pressure vessel; 
     FIG. 9 is enlarged view of a seal for the shaft of the agitating mechanism; 
     FIG. 10 is enlarged view of the vent; 
     FIGS. 11A-11C is a flow chart of a control process; 
     FIG. 12 is a schematic of a control panel; 
     FIG. 13 is a chart of an example of temperature and pressure relative to time in the pressure vessel and symbolic of the output from the controller; 
     FIG. 14 is a schematic view of an alternative apparatus having a carcass loading door; 
     FIG. 15 is another alternative embodiment with a mobile apparatus; 
     FIG. 16 is an end view of an alternative pressure vessel with a portion broken away showing the interior including paddles; 
     FIG. 17 is a side view of alternative pressure vessel according to the invention with portions shown in section; and 
     FIG. 18 is a front view of an eccentric rotor with horizontal arm and blades. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A description of preferred embodiments of the invention follows. 
     Referring now to FIG. 1, a pressure vessel  10  is a horizontally disposed cylindrical vessel with an inlet port  12  and an outlet port  14 . The pressure vessel  10  is sometimes referred to as a hydrolysis vessel since biological waste, such as tissue, is broken down in the vessel, however the element of water need not be added to the vessel as explained below. 
     The pressure vessel  10  is jacketed with a steam jacket  16 . The inlet and outlet ports  12 ,  14  are capable of being hermetically sealed. In the embodiment depicted in FIG. 1, the inlet port  12  is provided with a pressure vessel lid. It will be appreciated by those skilled in the art that other means for obtaining a hermetic seal, for example a knife-gate closure, may be used without departing from the scope of the present invention. In the embodiment shown in FIGS. 1 and 2, the inlet port  12  is positioned at the top of the pressure vessel  10 , thereby facilitating loading by means of a conveyor belt. Preferably, the inlet port  12  is provided with an extended neck  18  to prevent liquids from splashing out of the pressure vessel  10  during the loading step. Advantageously, a substantially downward flow of air is induced in the inlet port  12  to prevent the escape of any airborne emissions during loading. The downward flow of air may be induced, for example, by applying a negative pressure in the inlet port  12 . 
     The pressure vessel  10  is provided with a shaft  20  which extends axially along the full length of the vessel  10 . The shaft  20  is powered by a drive mechanism  22 . 
     The shaft  20  is also provided with mixing paddles  24  to tumble the waste against the heated walls of the pressure vessel  10  thereby facilitating uniform heating of the waste. In the embodiment shown in FIG. 1, the mixing paddles  24  are depicted as directional scoop blades. The directional scoop blades serve to mechanically break the waste into smaller components and to tumble the waste against the walls of the pressure vessel  10  when rotated in one direction and to direct the waste towards the outlet port  14  during an unloading step when rotated in the opposite direction. Rotation of the mixing paddles  24  during loading of the pressure vessel  10  allows the vessel  10  to be tightly loaded with waste. The mixing paddles  24  may be provided with a mechanism to adjust the tolerance between the mixing paddles  24  and the wall of the pressure vessel  10 . As shown in FIG. 1, the mixing paddles  24  at both ends of the pressure vessel  10  may also be provided with a scraper  26  to facilitate removal of the waste during the unloading step. In the embodiment shown in FIG. 1, the mixing paddles  24  are arranged about the shaft  20  at an angle of 180 relative to one another. However, the mixing paddles  24  may be arranged at angles of 120 or 90 relative to each other, such that efficient mixing of the waste is provided during sterilization. Two or more mixing paddles  24  may extend from the same point on the shaft  20  or may be spaced radially along the shaft  20  as shown in FIG.  1 . 
     The pressure vessel  10  is heated by pressurizing the steam jacket  16  with steam. The steam is not in direct contact with the waste being treated and any steam which condenses inside the steam jacket  16  is drained via a trap  28  for reheating in a boiler before being returned to the steam jacket  16 . This is particularly advantageous as compared to a conventional autoclave wherein steam condensate represents an energy loss of approximately 18%. Furthermore, the steam condensate increases the moisture content of the waste which corresponds to increased weight and problems with handling after the sterilization cycle. In accordance with the present invention, the steam does not directly contact the waste so that substantially all of the condensate may be recovered and recycled. Moreover, the waste does not pick up any excess moisture. 
     The heating cycle may be further enhanced by providing heat to the interior of the shaft  20 . This may be accomplished by providing a steam line through the drive mechanism  22  to the interior of a hollow shaft  20 . The condensate may be directed to the condensate line connected to the trap  28 . 
     In operation, biomedical and/or other hazardous waste material is loaded into the pressure vessel  10  through the inlet port  12 . Preferably, the mixing paddles  24  of the shaft  20  are rotated by activating the drive mechanism  22  to enable the pressure vessel  10  to be loaded to a greater capacity. The shaft  20  is preferably rotated at a low rotational speed, for example at about 5 rpm, to reduce splashing of liquids through the inlet port  12  while the waste is being loaded. A downward flow of air is advantageously induced in the inlet port  12  to prevent the escape of airborne emissions through the inlet port  12  during loading. The plastic bags and boxes in which the waste is stored are broken by the action of the rotating mixing paddles  24  and the waste is broken into smaller components. 
     The inlet port  12  is then hermetically sealed and the integrity of the seal between the pressure vessel  10  and the inlet and outlet ports  12 ,  14 , respectively, is confirmed by conventional electrical interlocks. 
     Steam is fed into the steam jacket  16  while the shaft  20  and the mixing paddles  24  are rotated. The shaft  20  is suitably rotated at a speed of from about 5 to 50 rpm so that successive portions of the waste material contact the walls of the pressure vessel  10  whereby the contents of the vessel  10  are heated substantially uniformly. The heating cycle may be further enhanced by the provision of steam to the interior of the shaft  20 . 
     When the interior of the pressure vessel  10  and the waste material contained therein reaches a temperature of 100° C. (212 F.), moisture in the waste material is converted to steam, thereby increasing the pressure within the pressure vessel  10 . Heating is continued until a pressure in the range of from about 15 to 100 psig, corresponding to a temperature in the range of from about 121° to 170° C. (250 to 338 F.), is achieved. Preferably, the pressure inside the pressure vessel  10  is regulated so that the temperature is not so high that plastic wastes chemically degrade. 
     The combined action of the mixing paddles  24  and the heat supplied by the steam jacket  16  cause the waste inside the pressure vessel  10  to further break down into smaller pieces. As bags and other containers are broken, any entrained air is released inside the pressure vessel  10 . Accordingly, cold spots are substantially eliminated. Furthermore, the effects of the type of material, density of the material, batch volume and the degree to which the vessel is loaded are substantially reduced in the pressure vessel  10  and process of the present invention, especially as compared to a conventional autoclave. 
     Circulation of the smaller portions of waste material within the pressure vessel  10  allows for a more even heat distribution and a reduction of temperature gradients throughout the waste contained therein, ensuring that all portions of the waste material are exposed to the appropriate temperature and pressure for a period of time sufficient to achieve sterilization of the material. It will be appreciated by those skilled in the art that the time required to achieve sterilization is substantially reduced as compared to the time required in a conventional autoclave wherein the heat must penetrate the relatively large pieces of waste material, especially waste contained in plastic bags and other containers. 
     There is generally sufficient moisture in biomedical waste to pressurize the pressure vessel  10  to the desired operating pressure and temperature. However, if the moisture content of the waste material is unusually low, for example less than 10%, there may be insufficient moisture to pressurize the pressure vessel  10 . A situation wherein the moisture content is insufficient can be detected by monitoring pressure and temperature gauges. If there is insufficient moisture, the pressure inside the pressure vessel  10  does not increase with an increase in temperature and the desired combination of temperature and pressure to effect sterilization may not be realized. This may be overcome by injecting high pressure steam, which may be tapped off the jacket supply steam line at 40 to 150 psig, directly into the pressure vessel  10  to increase the moisture content therein. In this way, the moisture content inside the pressure vessel  10  is not unduly increased. Alternatively, water may be added to the pressure vessel  10  during the loading step. However, this method is not as efficient and not as easy to monitor. 
     A thermocouple and temperature controller can be used in a preferred embodiment, however, in certain embodiments it is not necessary to monitor or control the temperature of the waste contained in the pressure vessel  10 , since pressure regulation will achieve the desired temperature control and reference may be made to standard steam tables to automatically determine the temperature which corresponds to an actual measured pressure, if desired. A low moisture condition can be sensed by monitoring pressure increases and the rate thereof. An operator can thus determine, after a period of heating, whether there is a sufficient increase in pressure to indicate sufficient moisture. 
     After the desired treatment time, the pressure vessel  10  is de-pressurized to atmospheric pressure. Preferably, the pressure vessel  10  is vented through a vent  30  at a controlled rate to a condenser  32 . The condenser  32  cools the gases from the pressure vessel  10 , for example, to a temperature of about 140 F., thereby condensing the moisture in the gas into the water contained in the condenser  32 . Any particulates present in the gas will be removed in the condenser  32 . 
     In the case where the waste material contains polyvinyl chloride, the gases from the pressure vessel  10  and, therefore, the condenser  32 , may contain hydrochloric acid. Accordingly, the water in the condenser  32  is preferably neutralized with a caustic feed prior to being drained to a sanitary sewer. 
     The cooled gases from the condenser  32  are nontoxic but may have an odor. Accordingly, the cooled gases are preferably subsequently passed through an air scrubber  34  for the appropriate heat, chemical and/or mechanical treatment which may dictated by local regulatory authorities. For example, with respect to heat treatment of gases, authorities in Ontario regulate that the gases be treated at 1800 F. with a residence time of 0.75 second before being discharged to the environment. 
     Preferably, the pressure vessel  10  is depressurized while heating is continued by maintaining steam input to the steam jacket  16 . In this way, substantially all of the moisture in the waste material will evaporate. While the volume of the waste is reduced during the entire process of the present invention, the reduced water content and mechanical agitation act during the de-pressurization step act to further reduce the volume of the treated waste. Depending on the moisture content, density and other characteristics of the waste, it is possible to reduce the volume to about one-fifth of the original volume of waste material. The reduced moisture content represents a decrease in the weight of the treated waste in addition to reduced landfill and transportation costs. 
     The outlet port  14  is then opened and the shaft  20  and mixing paddles  24  are rotated in a direction to cause the treated waste to move toward the outlet port  14 . The scrapers  21  assist in removing the waste from the end walls of the pressure vessel  10 . The hydrolysed waste material is thus emitted from the vessel  10 . 
     The entire process can, of course, be accurately controlled in terms of time, temperature, pressure and flow. For example, during de-pressurization of the pressure vessel  10 , the gas flow can be controlled, or shut off, if the operating parameters of the condenser  32  and the air scrubber  34  deviate from normal values to an unsafe level. Similarly, the operating time, temperature and pressure of the pressure vessel  10  can be interlocked with the vent  30  to prevent gases from escaping prior to sufficient sterilization of the waste. These indicators can be recorded on a strip or circular graph, as is commonly used in conventional autoclaves. The control system could also be adapted to include information on waste classification and waste origin on the graph. 
     In accordance with the present invention, it is possible to provide economic and effective waste treatment at individual medical treatment facilities. It may be feasible to utilize existing steam plants at these medical treatment facilities as an energy source. Furthermore, the cost and potential hazards associated with the transport of biomedical waste would be eliminated. 
     While it is preferable to avoid transport of untreated biomedical waste, a central waste treatment facility based on the process of the present invention could be used to serve a number of medical treatment facilities. The latter waste treatment facility may be constructed as illustrated in FIG.  2 . 
     In the case where biomedical and/or other hazardous waste must be transported to a central waste treatment facility, the waste is preferably transported in a refrigerated truck  38  to a collection area  40 . The waste material is conveyed to a treatment area  42 , for example, via a belt conveyor  44 . The waste material is then loaded into the pressure vessel  10  in the treatment area  42 . After the waste has been sufficiently sterilized, the pressure vessel  10  is de-pressurized by venting the gases to the condenser  32 . The cooled gases which have not condensed in the condenser  32  are treated in the air scrubber  34  and vented to the atmosphere through an air scrubber stack  46 . The de-watered waste material is unloaded from the pressure vessel  10  and conveyed to a loading area  48 , for example, via a screw conveyor  50 . The treated waste is then transported to a landfill site by a truck  52 . 
     The treatment facility illustrated in FIG. 2 is significantly less expensive to construct and operate than an incinerator facility of equal capacity. 
     A waste treatment plant, constructed as illustrated in FIG. 2, can include one or two boiler stacks and a small fume incinerator stack protruding above the roof. Furthermore, the plant does not emit any discernible odors or display large visible plumes of smoke from the stacks. 
     A schematic of an alternative embodiment of a processing apparatus  60  is shown in FIG.  3 . The processing apparatus  60  has a pressure vessel  62 , a heating jacket  64  substantially surrounding the pressure vessel  62 , a shredder  66 , an agitating mechanism  68  with a driver  70 , a vapor condensing system  72  and a controller  74 . The pressure vessel  62  has an inlet port, a loading door  76 , and an outlet port, an unloading door  78 . The loading door  76  is for receiving the untreated waste. The waste does not require any pre-processing treatment. 
     The pressure vessel  62  is substantially a cylindrical tube with a domed end. The pressure vessel  62  is surrounded by the heating jacket  64  which is capable of transferring heat to the exterior walls  82  of the pressure vessel  62 . One embodiment of the heating jacket  64  is a space  84  defined by the exterior walls  82  of the pressure vessel  62  and an outer exterior wall  86 ; this double walled vessel is capable of containing a heated liquid or gas. An alternative embodiment of the heating jacket  64  is heated elements embedded in a material, such as heating wires in an electrically insulative but thermally conductive material. The heating jacket  64  is covered with an insulating material such that the heat is directed towards the pressure vessel and not to the surrounding environment, such as a waste treatment room. 
     In a preferred embodiment, the heating jacket  64  is a steam jacket. The steam flows from a boiler in a steam line  88  through a first steam valve  90  and a second steam valve  92 , which can operate manually and be connected to the controller  74  to operate automatically, into the space, volume,  84  of the steam jacket  64 . The steam in the steam jacket  64  is not in direct contact with the waste being treated in the pressure vessel  62 . Any steam which condenses inside the steam jacket  64  is drained via a steam trap  94  for reheating in the boiler before being returned to the steam jacket  64 . This is particularly advantageous as compared to a conventional autoclave wherein steam condensate represents an energy loss of approximately 18%. 
     The steam line  88  is in addition connected to the pressure vessel  62  via a third steam valve  96  to allow the addition of steam to the pressure vessel  62  if needed, as described below. The pressure vessel  62  is also connected to the vapor condensing system  72  through a vapor exhaust line  97  and a fourth steam valve  98 . The steam valves  90 ,  92 ,  96 , and  98  are controlled by the controller  74  as explained below. 
     It is recognized that the third steam valve  96  and the fourth steam valve  98  could be combined into one three-way valve having the positions of off; steam from the boiler to the pressure vessel; and steam/vapor from the pressure vessel to the vapor condensing system. Steam from the boiler is not fed directly to the vapor condensing system. 
     The steam line  88  is connected to the pressure vessel  62 , in addition to through the third steam valve  96 , through a venting/filter system  100  attached to the pressure vessel. The venting/filter system  100  limits what particles leave the pressure vessel towards the vapor condensing system  72 . The venting/filter system  100  will be described in detail below in reference to FIG.  10 . 
     In addition to the vapor exhaust line  97  that carries vapor from the pressure vessel  62  to the vapor condensing system  72  of the vented emission treatment system  101 , a second line extends from the venting/filter system  100  to a gas portion  118  of the vented emission treatment system  101 . The line is part of a negative air pressure device  102  and has a fan  104  for creating a low pressure to draw air into the pressure vessel  62  through the loading door when loading to prevent the escape of any airborne emission during loading during filing. 
     The vapor condensing system  72  receives the steam, moisture or gas that is drawn away or forced away from the pressure vessel through the venting/filter system  100 , as described below. The vapor condensing system  72  has a cooling system  108 , which, in a preferred embodiment, is connected to a water system  110  such a city potable system, a fire drain pipe system, or other water source including gray water. The steam, moisture or gas which leaves the pressure vessel  62  is cooled and turned back into a liquid by the vapor condensing system  72  by the water from the water system  110  flashing the steam into liquid in the cooling system  108  prior to placing the steam, which is now a liquid, into a sewer system. The vapor condensing system  72  has a temperature sensor  112  which monitors the temperature of the water leaving the cooling system  108  and entering the sewer system. The temperature sensor  112  is connected to a valve  114  in the line from the pressure vessel through a controller  116 . The valve  114  limits the flow of steam into the cooling system  108  so that the water from the water system  110  is capable of keeping the temperature of the liquid entering the sewer system below 65.5° C. (150° F.), as explained below. The controller  116  for monitoring the temperature can be a portion of the controller  74 . 
     Those gases in the vapor condensing system  72  which are not condensible are vented through the gas portion  118  of the vented emission treatment system  101 . The gas portion  118  is connected to the cooling system  108  through a vent pipe  120 , similar in concept to a vent stack in a normal sewer system. The gas portion  118  has an active charcoal filter or a HEPA filter at the top of the stack through which the gases pass in order to remove odor. All the steam, moisture or gas has been retained in the pressure vessel for the designated temperature and time period and therefore can be treated prior to discharging and can be treated as normal waste. 
     The agitating mechanism  68  has a shaft  120  which extends longitudinally through the pressure vessel  62  and is connected to the driver  70 . The driver  70  in a preferred embodiment has an electric motor  122  which rotates the shaft  120  via a transmission mechanism  124 , such as a gear box, a chain, or a belt, as best seen in FIG.  4 . The agitating mechanism  68  has a plurality of paddles  126  which are located in proximity to the walls  82  of the pressure vessel  62  and spaced from the shaft  120  each by an arm  128 . The paddles are directional scoop blades which serve to mechanically break the waste into smaller components and to tumble the waste against the walls  82  of the pressure vessel  62  when rotated in one direction, thereby facilitating uniform heating of the waste. The paddles  126  direct the waste towards the outlet port, unloading door,  78  when rotated in the opposite direction. Rotation of the mixing paddles  126  during loading of the pressure vessel  62  allows the pressure vessel  62  to be tightly loaded with waste. 
     The shredder  66  is located in proximity to the unloading door  78  of the pressure vessel  62 . The shredder  66  takes the waste which has been treated in the pressure vessel  62 , as explained below, and further breaks up and shreds the waste into smaller pieces. The shredder  66  is not required to process the biomedical waste to result in sterile waste. The shredder  66  is desired to take the treated waste and further shred it so that the waste no longer has the look of medical waste and makes apparent to medical waste handlers that the waste has been treated. 
     The entire processing apparatus is controlled by the controller  74 . The controller  74  takes inputs from monitors and sensors, and the controller  74  administers the process and records data. The controller  74  will be explained in greater detail below. 
     Referring to FIG. 4, the pressure vessel  62  is substantially a cylindrical shell with domed ends to create the closed vessel. While the operating pressure is not considered extremely high pressure, it is desired in the preferred embodiment to minimize the openings in the pressure vessel  62 . In a preferred embodiment, the pressure vessel is made from 1 inch thick steel. In addition to the inlet port  76 , seen in FIGS. 3 and 6, and the outlet port  78 , the pressure vessel has a pair of openings  130  for receiving the shaft  120  of the agitating mechanism  68 . Each end of the shaft  120  extends through a seal  132  in the opening  130 . The seal  132  prevents the seepage of waste out of the pressure vessel  62 , as explained below. The shaft  120  is supported at each end by a bearing  134 , located outside of the pressure vessel  62 . The pressure vessel  62  also has a hole  136 , as seen in FIG. 6, to which the venting/filter system  100  is connected. In a preferred embodiment, the hole has a 4 inch diameter. The pressure vessel  62  in addition has two openings for monitors or sensors. 
     A pressure sensor  138 , as seen in FIG. 6, monitors the pressures and in a preferred embodiment is located in the upper portion of the pressure vessel  62 . A temperature sensor  140  measures the temperature within the pressure vessel  62 . In a preferred embodiment, the temperature sensor  140  is located in the lowest portion of the pressure vessel  62 . While the pressure of the pressure vessel  62  is generally uniform throughout, the temperature is more likely to vary in the pressure vessel  62 , at least initially. The temperature is the lowest generally at the bottom initially as explained below. The temperature sensor  140 , a thermocouple, has an iron-constantan tip. The temperature sensor, such as the one described above, is sold by Honeywell. The outer wall  86  of the heating jacket  64  is formed such that there is an opening around the temperature sensor  140 . An insulating plug or ring  142  is located between the temperature sensor  140  and the wall  82  of the pressure vessel  62  as seen in FIG. 5 so that the outer wall  82  of the pressure vessel  62  and the heating jacket  64  do not influence the reading of the temperature sensor  140 . Both the temperature sensor  140  and the pressure sensor  138  are connected to the controller  74  shown in FIG.  3 . 
     Still referring to FIG. 4, the heating jacket  64  in a preferred embodiment is a steam jacket and is defined by the wall  82  of the pressure vessel  62  and the outer exterior wall  86 . In a preferred embodiment the outer exterior wall  86  is ⅜ to ½ inch thick steel and has a 2 inch thick insulating layer of glass fiber or mineral wool on the outside and an outer layer of stainless steel covering the insulating layer. In addition to opening to allow access to openings in the wall  82  of the pressure vessel, the outer exterior wall  86  has three additional openings: an opening  144  for allowing steam from the steam line  88  into the space  84  in the steam jacket  64 , an opening  146  to the steam trap  94 , as seen in FIG. 3, for the collection of condensed steam; and an opening  148  for the removal of trapped air in the steam jacket  64 . 
     The inlet port, a loading door,  76  of the pressure vessel  62  is located 45° from the top on one side in a preferred embodiment, as shown in FIG. 6, for facilities where the waste is placed in the processing apparatus  60  from within the same waste treatment area, in contrast to from a room above as in the first embodiment. The loading door  76  is located generally at the opposite end of the pressure vessel  62  from the outlet port, an unloading door  76 , as best seen in FIG.  3 . The unloading door  78  is located at one end of the pressure vessel  62  at the lowest level of the pressure vessel  62  so that the agitating mechanism  68  can push the waste out after treating. The loading door  76  is for receiving the untreated waste. The waste does not require any preprocessing treatment prior to being placed through the loading door  76  into the pressure vessel  62 . 
     Referring to FIGS. 4 and 6, the shaft  120  of the agitating mechanism  68  extends longitudinally through the pressure vessel  62  and is connected to the driver  70 , the electric motor  122  in preferred embodiment via a gear drive  124 . Located at the other end of the pressure vessel from the electric motor  122  is a bearing  134 , a pillow block bearing, for rotatably receiving the other end of the shaft  120 . The plurality of paddles  126  are mounted to the shaft  120  by the arm or rod  128  extending from a clamp  150  bolted to the shaft  120  to the paddle  126 . Each paddle  126  has a pair of blades  152  and  154 . The blades  152  and  154  are joined at one edge  156 . One blade  152  is parallel to the shaft  120  and generally moves the waste in a series of planes perpendicular to the shaft  120  as the shaft  120  rotates in one direction, for example clockwise as shown in FIG.  6 . The other blade  154  is angled relative to the shaft  120  such that the face of the blade opens towards the end of the pressure vessel  62  that has the unloading door  78 . Therefore when the shaft  120  is rotated in the opposite direction, for example counter-clockwise in FIG. 6, the waste is moved towards the unloading door  78 . 
     The pressure vessel  62  has a series of knife edges  158  that interact with the blades  152  and  154  of the paddles  126  to reduce or eliminate tangling of waste on the paddles  126 . The knife edges  156  are located on the walls  82  of the pressure vessel  62 , and on the upper half of the pressure vessel  62  in a preferred embodiment. 
     An enlarged view of the interaction of the blades  152  and  154  of a paddle  126  and the knife edge  158  mounted on the wall  82  of the pressure vessel  62  is shown in FIGS. 7 and 8. FIG. 7 is a sectional view through the arm or rod  128  of the paddle  126 . The blade  152  which is parallel to the shaft  120  is shown below and the blade  154  which is angled is shown on the top, therefore if the paddle  126  is rotating downward in this FIG. the waste would be rotated in planes parallel to the shaft  120  and if the paddle is rotating upward as seen in this FIG., the waste would be moved to the right, towards the end of the pressure vessel  62  that has the unloading door  78 . 
     The blades  152  and  154  each have a slot  160 , shown in hidden line, which is aligned with the knife edge  158  mounted on the wall  82  of the pressure vessel  62 . The paddle  126  as it rotates may pick up waste which gets tied up or wound around the paddle  126  and does not drop back into the accumulation of waste located in the lower portion of the pressure vessel  62  as the paddle  126 , or at least the blades  152  and  154 , rises above the top of the accumulation of waste in the pressure vessel  62 . Typically waste that would get wound around the paddle  126  includes cloth bandages, sheets, large plastic bags, rubber hoses and other fibrous material or plastic material items that are flexible and are large enough to wrap around. The knife edges  158  cut or tear those items that are caught on the blades  152  and  154  of the paddle  126  and are brought into engagement with the knife edge  158 . In a preferred embodiment, the knife edges  158  are located on the upper portion of the pressure vessel  62 , so that the likelihood of damage to the knife edges  158  by large heavy objects, such as metal bars and toilet seats is minimized. It is recognized that even when treating medical waste, the processing apparatus  60  will receive items that are not considered medical waste, but nonetheless must be handled by the apparatus  60 . 
     A perspective view of the knife edge  158  as the slot  160  in the blades  152  and  154  of the paddle  126  pass over is shown in FIG.  8 . The knife edge  158  is triangular in cross section and trapezoid shape with the largest edge spaced from the wall  82  of the pressure vessel  62 . The ends are triangular in shape with the apex of each end projected outward from the base and spaced from the wall  82  of the pressure vessel  62 . The knife edge  158  is secured to the wall  82  of the pressure vessel  62  by a series of bolts in a preferred embodiment. If a knife edge  158  is damaged, it can be replaced by unbolting the damaged knife edge  158  and installing a new knife edge. The paddles  126  which are adjacent to the domed ends, especially the end having the unloading door  78 , are preferred to have a series of knife edges  158  as best seen in FIG.  4 . While the knife edge  158  is shown as a solid bar in FIGS. 7 and 8, it is recognized that the knife edge  158  could take other forms including a right angle bar with the long edges engaging the wall of the pressure vessel. 
     One of the seals  132  for the shaft  120  of the agitating mechanism  68  is shown in FIG.  9 . It is not desired for the biomedical waste including liquid and gas to leave the pressure vessel  62  prior to the completion of the sterilization of the waste. With a pressure differential between the pressure vessel  62  and the outside and the shaft  120  extending through an opening  130  in the pressure vessel  62  and the shaft  120  rotating, there would be a tendency for gas or liquid to escape from the pressure vessel. The seals  132  prevent the escape of fluid and gas from the pressure vessel  62 . 
     The seal  132  has a sleeve  164  which in a preferred embodiment is made of stainless steel and is retained in the opening  130  in the pressure vessel by bolts. The seal  132  has a packing gland  166  for retaining a pair of shaft packings  168  in a channel  170  defined by the sleeve  164 . A lantern ring  172  is interposed between the shaft packings  168  in the channel  170 . 
     The seal  132  has a differential pressure controller  174 , a mechanical device. The differential pressure controller  174  is connected to a pressure sensing line  176  which opens onto the pressure vessel  62  for sensing the pressure in the vessel  62 . The differential pressure controller  174  in addition has a line  178  connected to a pressurized water source such as a city water system. The pressurized water source has to have a pressure higher than the pressure in the pressure vessel  62 . The differential pressure controller  174  compares the pressure from line  178 , the city water system, and the pressure sensing line  176 . By varying the pressure from line  178 , the differential pressure controller  174  applies a pressure through a line  180  to the lantern ring  172  using the city water which is 1-5 psi higher than the pressure sensed in the pressure sensing line  176 . 
     The pressures on the shaft packing  168  between the opening to the pressure vessel  62  and the lantern ring  172  are therefore 1-5 psi higher than the pressure in the pressure vessel  62 . If the shaft packing  168  becomes worn, there is a tendency for liquid or steam to leak past the shaft  120 , the pressurized water, city water, will flow into the vessel  62 , rather than the medical waste liquid and gases flowing out of the pressure vessel  62 . A flow meter located on the line  180  to the lantern ring  172  can detect if the shaft packings  168  are worn by the flow of water. The packing gland  166  is tightened periodically to maintain the appropriate tension on the shaft packings  168  and the lantern ring  172 . In the alternative, springs can be used to maintain the appropriate tension. 
     The venting/filter system  100  has a venting bottle  182  which is connected to the pressure vessel  62  through a line  184  as seen in FIG.  10 . The venting bottle  182  is also connected to a line  186  which is connected to the boiler through a steam line  88  and through two steam valves  90  and  96 , as seen in FIG. 3, and connected to the vapor condensing system  72  through another steam valve  98 , as seen in FIG.  3 . Still referring to FIG. 10, the venting/filter system  100  has a narrow neck portion  188 , which is connected to line  184 , and an enlarged area  190 . The velocity of the steam/gas is reduced when it enters the enlarged area  190  as explained below. Located within the enlarged area  190  is a cylindrical mesh  192  having a solid base  194  and an annular ring top  196  with an opening  198  to allow steam/gas to pass into the line  186 . The cylindrical mesh  192  prevents small and lighter waste particles from entering the line to the vapor condensing system  72  and the steam valve  98 . The concern is not with the particles being infectious medical waste, but with clogging the system. 
     The venting/filter system  100  has a flow measuring device or a pressure sensor device  200  upstream of the cylindrical mesh  192 . In a preferred embodiment, the device is a pressure sensor device  200  located in the line  186 . The device  200  is connected to the controller  74 , as seen in FIG. 3, in order to sense when the mesh  192  has become clogged. 
     The venting bottle  182  of the venting/filter system  100  has an additional opening  204  for the negative air pressure device line  102 . The line of the negative air pressure device  102  has a valve  206 , as seen in FIG. 3, for limiting the flow through the line when it is not desired to create a back flow when loading. The opening  204  at the venting bottle  182  has a screen  208  to prevent small and lighter waste particles from settling in the line for the negative air pressure device  102  even though the line is closed when particles are typically in the venting bottle  182 . 
     The operation of the processing apparatus  60  will be described with respect to FIG.  11 . The waste, be it biomedical, another type of hazardous waste material or other waste where treatment is desired, is loaded into the pressure vessel  62  through the inlet port  76 . In a preferred mode, a downward flow of air is induced in the inlet port  76  to prevent the escape of airborne emissions through the inlet port  76  during loading. The downward flow of air is created by the negative air pressure device  102 . The controller  74  opens the valve  206  and turns on the fan  104  in the negative air pressure device  102  to pull air from the pressure vessel  62 , therein creating a downward flow of air in the inlet port  76 . The air pulled from the pressure vessel  62  is sent through the active charcoal filter or HEPA filter of the gas portion  118  of the vented emission treatment system  101 , as seen in FIG. 3, to remove particles. A monitor can be located in the negative air pressure device  102  to ensure a low pressure is being created in the pressure vessel  62 . An alarm located on the controller  74  can indicate when there is not a proper flow through the negative air pressure device  102 . 
     In a preferred mode of operation, the agitating mechanism  68  is rotated by the driver  70  to enable the pressure vessel  62  to be loaded to a greater capacity. The shaft  120  in this preferred mode is rotated at a low rotational speed, for example at about 5 rpm, to reduce splashing of liquids through the inlet port  76  while the waste is being loaded. The waste, including the plastic bags and boxes in which other waste is stored, is broken into smaller components by the action of the rotating paddles  126 . 
     The inlet port  76  is then hermetically sealed and the integrity of the seal between the pressure vessel  62  and the inlet port  76  and the outlet ports  78  is confirmed by conventional electrical interlocks. The negative air pressure device  102  is connected via the controller  74  to the loading door  76 , such that the fan  104  is shut off and the valve  206  is closed when the loading door  76  is closed. With the pressure vessel  62  loaded and a start button, as seen in FIG. 12, pushed when in an automatic mode, the controller  74  has confirmed that the inlet port  76  and the outlet port  78  are closed and begins the sterilization process. A printer/recorder  212 , as seen in FIG. 12, on the controller  74  is activated for a permanent recorder of the process. The first steam valve  90  and the second steam valve  92  are opened to allow steam to flow from the boiler to the space  84  of the steam jacket  64 . The opening  148  allows trapped air to be bled. In a preferred embodiment, the steam is produced by a boiler not controlled by the controller  72  of the processing apparatus  60 . 
     The controller  74  monitors the pressure through the pressure sensor  138  and the temperature through the temperature sensor  140 . While the controller  74  is monitoring parameters and steam is entering the steam jacket  64 , the shaft  120  and the paddles  126  of the agitating mechanism are rotated. In a preferred embodiment, the shaft  120  is suitably rotated at a speed of from about 5 to 50 rpm so that successive portions of the waste material contact the walls  82  of the pressure vessel  62  whereby the contents of the vessel  62  are heated substantially uniformly. Similar to the first embodiment, the heating cycle may be further enhanced by the provision of steam to the interior of the shaft  120 . 
     The temperature is measured at the bottom of the pressure vessel  62 , since any fluid located in the waste will drain to the bottom of the pressure vessel  62  when freed from the vial, box, bag or other container which contained it on entry into the pressure vessel  62 . The fluid is not lifted by the paddles  126  of the agitating mechanism  68  and forms a large mass of liquid to heat at the bottom of vessel  62 . This mass of fluid typically will take the longest to heat. Therefore the temperature sensor, thermocouple  140 , typically measures the lowest temperature in the pressure vessel  62 . 
     When the interior of the pressure vessel  10  and the waste material contained therein reaches a temperature of 100° C. (212 F.), moisture in the waste material is converted to steam, thereby increasing the pressure within the pressure vessel  62 . Heating is continued until the temperature is in the range of from about 121° to 170° C. (250 to 338 F.) and a pressure in the range of from about 15 to 100 psig. It is not desired to raise the temperature so high as to chemically degrade the plastic. Therefore when certain plastics are contained in the waste, the temperature of the pressure vessel  62  should be limited to 132° C. (270° F.). 
     The combined action of the paddles  126  of the agitating mechanism  68  and the heat supplied by the steam jacket  64  cause the waste inside the pressure vessel  62  to further break down into smaller pieces. As bags and other containers are broken, any entrained air is released inside the pressure vessel  62 . Accordingly, cold spots are substantially eliminated. Furthermore, the effects of the type of material, density of the material, batch volume and the degree to which the vessel is loaded are substantially reduced in the pressure vessel  62  and process of the present invention, especially as compared to a conventional autoclave. 
     Circulation of the smaller portions of waste material within the pressure vessel  62  allows for a more even heat distribution and a reduction of temperature gradients throughout the waste contained therein, ensuring that all portions of the waste material are exposed to the appropriate temperature and pressure for a period of time sufficient to achieve sterilization of the material. 
     There is generally sufficient moisture in biomedical waste to pressurize the pressure vessel  62  to the desired operating pressure and temperature. However, if the moisture content of the waste material is unusually low, for example less than 10%, there may be insufficient moisture to pressurize the pressure vessel  10 . A situation wherein the moisture content is insufficient is detected by the controller  74  by monitoring the pressure sensor  138  and the temperature sensor  140 . If there is insufficient moisture, the pressure inside the pressure vessel  62  does not increase proportional with an increase in temperature and the desired combination of temperature and pressure to effect sterilization may not be realized. This may be overcome by injecting high pressure steam. The controller  74  opens the steam valves  90  and  96  so that the steam from the boiler, the jacket supply steam, is placed directly into the pressure vessel  62  through the venting/filter system  100  to increase the moisture content of the pressure vessel  62  and the waste. In this way, the moisture content inside the pressure vessel  62  is not unduly increased. Alternatively, water may be added to the pressure vessel  10  during the loading step. However, this method is not as efficient and not as easy to monitor. 
     After the desired treatment time at proper pressure and temperature, the pressure vessel  62  is de-pressurized to atmospheric pressure by the controller  74 . The desired treatment time is dependent on the temperature and pressure in the pressure vessel  62 . The following is a table of times for a preferred embodiment for the temperature and pressure given. The temperature of 170° C. is typically used for large animals such as described in the next embodiment. FIG. 13 shows an example of temperature and pressure in the pressure vessel  62  during the various stages of the sterilization process and a typical time of each process. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                   
               
               
                   
                   
                 Time (Minutes) 
               
               
                 Temperature (° C.) 
                 Pressure (PSI) 
                 (Sterilization Stage) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 121 
                 15 
                 30 
               
               
                 132 
                 38 
                 15 
               
               
                 170 
                 100 
                 ≦15 
               
               
                   
               
             
          
         
       
     
     The controller  74  de-pressurizes the pressure vessel  62  by opening the steam valve  98  which vents the steam and gas from the pressure vessel  62  through the venting/filter system  100  to the vapor condensing system  72 . The controller  74  turns on the flow of water in the cooling system  108  and regulates the valve  114  through the controller  116  allowing only enough steam and gas from the pressure vessel  62  as the cooling system  108  can cool. The output temperature, as monitored by the temperature sensor  112 , determines how much steam and gas the cooling system  108  can cool. Those gases in the vapor condensing system  72  which are not condensible are vented through the gas portion  118  of the vapor condensing system  72 . The gas portion  118  has an active charcoal filter or a HEPA filter at the top of the stack through which the gases pass in order to remove odor. All the steam, moisture or gas has been retained in the pressure vessel for the designated temperature and time period and therefore is treated prior to discharging and can be treated as normal waste. 
     The temperature in the pressure vessel  62  is kept in the range of 121° to 132° C. (250° to 270° F.) to achieve sterilization without having chemical breakdown of the plastics. Certain plastics such as polyvinyl chloride can give out a hazardous gas if heated to a high temperature. 
     While the pressure vessel  62  is being depressurized, the venting/filtering system is ensuring that no small or lighter waste particles enter the line to the vapor condensing system  72  and the steam valve  98 . The concern is not with the particles being medical waste, but that the particles may clog the system. On initiating the venting, there will be a strong velocity through the line  184  from the pressure vessel  62  to the venting bottle  182 , because of the increased pressure in the pressure vessel  62 . Any waste particles that are lifted by the increased velocity will be slowed down in the enlarged area  190  of the venting bottle  182 . Most waste particles will gravitate back through the line  184  into the pressure vessel  62 . Smaller and lighter waste particles will be prevented from exiting the venting bottle  182  by the cylindrical mesh  192 . Therefore, only clean steam and gases will exit through the opening  198  and into the line  186 . The controller  74  will be monitoring to determine if the cylindrical mesh  192  is clogged. In a preferred embodiment, the controller  74  monitors by comparing the pressure in the line  186  to the pressure in the pressure vessel  62  by comparing the pressure sensor  200  to the pressure sensor  138 . When the controller  74  determines that the flow is being blocked through the mesh, by a large pressure differential between the pressure in the line  186  and the pressure in the pressure vessel  62 , the controller  74  opens the steam valve  96  so that a shot of live steam is sent into the pressure vessel  62 . The force of the steam is sufficient to clean the particles off of the cylindrical mesh  192 . The steam valve  90  should already be open, but if not the controller  74  will also open that valve. 
     Preferably, the pressure vessel  10  is depressurized while heating is continued by maintaining steam input to the steam jacket  16 . In this way, substantially all of the moisture in the waste material will evaporate. The decrease in pressure results in flashing a large portion of liquid to vapor. While the volume of the waste is reduced during the entire process of the present invention, the reduced water content during the de-pressurization step act to further reduce the volume of the treated waste. Depending on the moisture content, density and other characteristics of the waste, it is possible to reduce the volume to about one-fifth of the original volume of waste material. The reduced moisture content represents a decrease in the weight of the treated waste in addition to reduced landfill and transportation costs. 
     Both during the sterilization, and the dehydration stages, the agitating mechanism  68  is moving the waste. During the de-pressurization stage, the controller  74  stops the agitating mechanism  68  in order to minimize the amount of particles that are pulled into the venting bottle  182  of the venting/filter system  100 . When the pressure in the pressure vessel  62  gets down to 2 psig, in a preferred embodiment, the controller  74  starts the shaft  120  of the agitating mechanism  68  by powering the electric motor  122 . The blade  152  is the front facing blade on each of the paddles  126  as the shaft rotates in the mixing direction, the clockwise direction as shown in FIG. 6, to move the waste in a series of planes perpendicular to the shaft  120 . The agitating mechanism  68  is mechanically breaking the waste into smaller components and facilitating uniform heating of the waste. 
     The knife edges  158  mounted on the upper half of the wall  82  of the pressure vessels interact with the blades  152  and  154  of the paddles  126  to reduce or eliminate tangling of waste on the paddles  126 . As the paddle  126  rotates it may pick up waste which gets tied up or wound around the paddle  126  and does not drop back into the accumulation of waste located in the lower portion of the pressure vessel  62  as the paddle  126 , or at least the blades  152  and  154 , rises above the top of the accumulation of waste in the pressure vessel  62 . Typical waste that would get wound around the paddle  126  includes cloth bandages, sheets, rubber hoses and other items that are flexible and of large length to width ratio. The knife edge  158  cut those items that are caught on the blades  152  and  154  of the paddle  126  and are brought into engagement with the knife edge  158 . 
     When the controller  74  determines that the de-hydration stage is completed either by a timer or in a preferred embodiment by monitoring the temperature in the pressure vessel  62  and noting an upswing in temperature, the controller  74  will stop the agitating mechanism  68  and closes the valves  90  and  92  to shut the steam to the steam jacket  64 . The controller  74  then will signal to the user that the unloading door  78  can be opened. With the outlet port, unloading door  78  opened, the controller  74  will initiate the agitating mechanism  68  in the opposite direction. The other blade  154 , which is angled relative to the shaft  120 , is the facing blade and engages the waste as the shaft  120  rotates in a counter-clockwise direction as seen in FIG. 6, therein moving the waste towards the unloading door  78 . 
     The knife edges  158  likewise interact with the blades  152  and  154  of the paddles  126  to reduce or eliminate tangling of waste on the paddles  126 . In that the waste is being moved to one end of the pressure vessel  62  there is an increased likelihood of tangling. Therefore, the paddles  126  which are near the ends of the pressure vessel  62  are adapted to interact with a multiplicity of knife edges  158 . The scrapers assist in removing the waste from the end walls of the pressure vessel  10 . The treated waste material is thus emitted from the vessel  10 . 
     The waste drops from the pressure vessel  62  into the shredder  66 , where it is further broken up and shredded. The treated shredded waste can be shipped away as declassified municipal waste. The controller  74  has produced a chart indicating parameters including pressure and temperature in the pressure vessel versus time. The temperatures and pressures given in FIGS. 11A-C are nominal ideal for a particular preferred embodiment. It is recognized that the temperature, pressure and revolutions per minute could vary. 
     While generally transparent to the user, the controller  74  is monitoring the seal  132  to ensure that there is no leakage. The seals  132  have the differential pressure controllers  174  which compare the pressure from line  178  and the pressure sensing line  176  and applies a pressure through a line  180  to the lantern ring  172  using the city water which is 1-5 psi higher than the pressure sensed in the pressure sensing line  176 . The pressures on the shaft packing  168  between the opening to the pressure vessel  62  and the lantern ring  172  are therefore 1-5 psi higher than the pressure in the pressure vessel  62 . 
     An alternative embodiment of a processing apparatus  260  is shown in FIG.  14 . The processing apparatus  260 , similar to the previous embodiment, has a pressure vessel  262 , a heating jacket  264  substantially surrounding the pressure vessel  262 , a shredder  266 , an agitating mechanism  268  with a driver  270 , a vapor condensing system, not seen in FIG. 14, and a controller  274 . The pressure vessel  262  has an inlet port, a loading door  276 , and an outlet port, an unloading door  278 . 
     Similar to the previous embodiment, the loading door  276  is for receiving the untreated waste. However, in contrast to the previous embodiment, the loading door  276  is spaced from the cylindrical pressure vessel  262  by an extended neck  280 . In addition, the loading door  276  is of the size that a carcass of an animal, such as a horse, can be placed in the extended neck. The extended neck  250  has a grinder  252  with a driver  254 . The waste does not require any pre-processing treatment prior to placing through the loading door  276 . 
     The pressure vessel  262  is substantially similar to the previous embodiment with the addition of the extended neck  250 . The heating jacket  264  surrounds the pressure vessel  262  and can also surround the extended neck  250 . The heating jacket  264  is capable of transferring heat to the exterior walls  282  of the pressure vessel  262 , including the extended neck  250  if desired. In a preferred embodiment, the heating jacket  264  is a steam jacket. The heating jacket  264  is covered with an insulating material such that the heat is direct to the pressure vessel and not to the surrounding environment, such as a waste treatment room. 
     The steam flows from a boiler in a steam line  288  through a first steam valve  290  and a second steam valve  292 , which can operate manually and connect to the controller  274  to operate automatically, into the jacket. The steam is not in direct contact with the waste being treated in the pressure vessel  262 . Any steam which condenses inside the steam jacket  264  is drained via a steam trap  294  for reheating in the boiler before being returned to the steam jacket  264 . 
     In addition, the steam line  288  is connected to the pressure vessel  262  via a third steam valve  296  to allow the addition of steam to the pressure vessel  262  if needed, for reasons given above in the previous embodiment. It is not likely that moisture will need to be added when the waste consists of a large animal in excess of 100 lbs and in many applications over 500 lbs. The pressure vessel  262  is also connected to the liquid/vapor handling system through a fourth steam valve  298 . As in the previous embodiment, the steam valves are controlled by the controller  274 . 
     The steam line  288  is connected to the pressure vessel  262 , in addition to through the third steam valve  296 , through a venting/filter system  300  attached to the pressure vessel. The venting/filter system  300  limits what particles leave the pressure vessel towards the vapor condensing system, similar to the previous embodiment. 
     In addition to the line that carries vapor from the pressure vessel  262  to the vapor condensing system  272 , a line for the negative air pressure device  302  extends from the venting/filter system  300  to a vapor portion of a vented emission treatment system  301 . 
     The vented emission treatment system, while not shown in FIG. 14, is similar to that described with respect to FIG. 3 in the previous embodiments. 
     The agitating mechanism  268  has a shaft  320  which extends longitudinally through the pressure vessel  262  and is connected to the driver  270 , an electric motor in a preferred embodiment. The agitating mechanism  268  has a plurality of paddles  226  which are located in proximity to the walls  382  of the pressure vessel  262  and spaced from the shaft  220  each by an arm  228 . The paddles are directional scoop blades as in the previous embodiment. The agitating mechanism  268  has a seal similar to that described in FIG. 9 with the previous embodiment. 
     The grinder  252  is located in the extended neck  250  of the pressure vessel  262 . The grinder  252  has a series of shafts  256  which extend longitudinally through the extended neck  250  and are connected to the driver  254  through a gearing arrangement  258 . The grinder  252  has a plurality of teeth  259  which intermesh to roughly grind the waste. By breaking down the carcass, the process is sped up by allowing the temperature in the pressure vessel  262  to achieve the uniform desired temperature more quickly. The grinder  252  has seals similar to those described with respect to the agitating mechanisms  68  and  268 . In loads which contains only a carcass(es) it may be desirable to have the pressure vessel  262  at temperature of 170° C. to speed the breakdown of the carcass. 
     The shredder  266  is located in proximity to the unloading door  278  of the pressure vessel  262 . The shredder  266  takes the waste which has been treated in the pressure vessel  262 , and further breaks up and shreds the waste into smaller pieces. The shredder  266  is not required to process the biomedical waste to result in sterile waste. 
     The entire processing apparatus is controlled by the controller  274 . The controller  274  takes inputs from monitors and sensors, and the controller  274  administers the process and records data. The controller  274  is similar to the previous embodiment, but in addition, it can control the grinder  252 . 
     In situations where untreated biomedical waste is located distant from a waste treatment or processing facility, a mobile processing apparatus  360 , as seen in FIG. 15 could be brought to the location. The mobile processing apparatus  360  could also be useful in cleaning up accidental spills on highways, at industrial and/or commercial sites, or at medical treatment facilities. The mobile processing apparatus  360  is a vehicle equipped with a pressure vessel  362 , a heating jacket  364  substantially surrounding the pressure vessel  362 , a shredder  366 , an agitating mechanism  368  with a driver  370 , a vapor condensing system  372 , a heat generator  380  and a controller  374 . The pressure vessel  362  has an inlet port, a loading door  376 , and an outlet port, an unloading door, located above a portion of the shredder  366 . The loading door  376  is for receiving the untreated waste. The waste does not require any pre-processing treatment. 
     The pressure vessel  362  is substantially a cylindrical tube with a domed ends. The pressure vessel  362  is surrounded by the heating jacket  364  which is capable of transferring heat to the exterior walls  382  of the pressure vessel  362 . The heating jacket  364  can be a space defined by the exterior walls of the pressure vessel  362  and an outer exterior wall; this double walled vessel is capable of containing a heated liquid or gas An alternative embodiment of the heating jacket  364  is heated elements embedded in a material, such as heating wires in an electrically insulative but thermally conductive material. The heating jacket  364  can be covered with an insulating material such that the heat is direct to the pressure vessel. 
     In a preferred embodiment, the heating jacket  364  is a steam jacket and the heat generator  380  is a boiler. The steam flows from the boiler  380  in a steam line  388  through a first steam valve and a second steam valve, which can operate manually and is connected to the controller  374  to operate automatically, into the jacket. The steam is not in direct contact with the waste being treated in the pressure vessel  362 . Any steam which condenses inside the steam jacket  364  is drained via a steam trap  394  for reheating in the boiler before being returned to the steam jacket  364 . 
     The steam line  388  is in addition connected to the pressure vessel  362  via a third steam valve to allow the addition of steam to the pressure vessel  362  if needed, similar to that described in the previous embodiments. The pressure vessel  362  is also, connected to the liquid/vapor handling system  372  through a fourth steam valve. The steam valves are controlled by the controller  374 . 
     The steam line is connected to the pressure vessel  362 , in addition to through the third steam valve, through a venting/filter system  390  attached to the pressure vessel  362 . The venting/filter system  390  limits what particles leave the pressure vessel towards the vapor condensing system  372 , as described above with respect to previous embodiments and FIG.  10 . 
     In addition to the line that carries vapor from the pressure vessel  362  to the vapor condensing system  372 , a second line extends from the venting/filter system  390  to the vapor condensing system  372 . The line is part of a negative air pressure device for creating a low pressure to draw air into the pressure vessel  362  during filling. 
     The vapor condensing system  372  receives the steam, moisture or gas that is drawn away or forced away from the pressure vessel through the venting/filter system  390 . The vapor condensing system  372  has a cooling system which in a preferred embodiment is connected to a water system. The steam, moisture or gas which leaves the pressure vessel  362  is cooled and turned back into a liquid by the vapor condensing system  372  by the water from the water system flashing the steam into liquid in the cooling system prior to placing the steam, which is now liquid, into a sewer system or holding tank. The vapor condensing system  372  can have a temperature sensor which monitors the temperature of the water leaving the cooling system. The temperature sensor is connected to a valve in the line from the pressure vessel through a controller. The valve limits the flow of steam into the cooling system so that the water from the water system is capable of keeping the temperature of the liquid entering the sewer system below 65.5° C. (150° F.). The controller can be a portion of the controller  374 . 
     Those gases in the vapor condensing system  372  which are not compressible are vented through a vapor portion of the vapor condensing system  372 . The vapor portion is connected to the cooling system through a vent pipe. The vapor portion has an active charcoal filter or a HEPA filter at the top of the stack through which the gases pass in order to remove odor. All the steam, moisture or gas has been retained in the pressure vessel for the designated temperature and time period and therefore treated prior to discharging and can be treated as normal waste. 
     The agitating mechanism  368  has a shaft  392  which extends longitudinally through the pressure vessel  362  and is connected to the driver  370 . The driver  370  in a preferred embodiment has a diesel engine which rotates the shaft  392  via a belt. The agitating mechanism  368  has a plurality of paddles which are located in proximity to the walls of the pressure vessel and spaced from the shaft each by an arm. 
     The shredder  366  is located in proximity to the unloading door of the pressure vessel  362 . The shredder  366  takes the waste which has been treated in the pressure vessel  362 , and further breaks up and shreds the waste into smaller pieces. 
     The entire processing apparatus is controlled by the controller  374  which takes inputs from monitors and sensors, and the controller  374  administers the process and records data. The controller  374  is similar to those explained above, but in addition controls the heat generator  380 . 
     In accordance with the present invention, it is possible to provide economic and effective waste treatment at individual medical treatment facilities. It may be feasible to utilize existing steam plants at these medical treatment facilities as an energy source. Furthermore, the cost and potential hazards associated with the transport of biomedical waste would be eliminated. The waste treatment process and apparatus of the present invention provides economic and effective treatment of biomedical and/or other hazardous waste. The waste is broken down and tumbled against the heated walls of the pressure vessel thereby maximizing heat transfer to the waste, especially as compared to conventional treatment in an autoclave. There are substantially no toxic or odorous gas emissions and only sterile treated water is released to sanitary sewers. Furthermore, energy consumption is reduced and treatment facilities are relatively inexpensive to construct and operate. 
     Referring to FIG. 16, an alternative pressure vessel  400  is shown with a cylindrical shell with domed ends to create the closed vessel. Similar to the previous pressure vessel, the pressure vessel  400  has a shaft  120  of an agitating mechanism  68  extending along vessel  400 . A plurality of paddles  126  are mounted to the shaft  120  by an arm or rod  128  extending from a clamp  150  bolted to the shaft  120  to the paddle  126 . Each paddle  126  has at least one blade  402 . In one embodiment, the paddle has a pair of blades. The blades are joined at one edge  404 . One blade is parallel to the shaft  120  and generally moves the waste in a series of planes perpendicular to the shaft  120  as the shaft  120  rotates in one direction. The other blade is angled relative to the shaft  120  such that the face of the blade opens towards the end of the pressure vessel  400  that has the unloading door  78 . Therefore when the shaft  120  is rotated in the opposite direction, for example counter-clockwise in FIG. 16, the waste is moved towards the unloading door  78 . 
     The blades have a knife edge  406  on their edges. The knife edge  406  interacts with a series of blocks  408  carried on the walls  82  of the pressure vessel  400 , and on the upper half of the pressure vessel  400  in one embodiment. The blocks  408  hinder rotation of the waste to allow the blades to cut the waste. 
     Referring to FIG. 17, an alternative pressure vessel  420  is substantially a cylindrical shell with domed ends to create the closed vessel. While the operating pressure is not considered extremely high pressure, it is desired in the preferred embodiment to minimize the openings in the pressure vessel  420 . In the embodiment, the pressure vessel  420  has a single port  422  for loading and unloading of waste. The shaft  424  of the agitating mechanism  426  extends through a single opening  428 . The shaft  424  extends through a seal  132  in the opening  428  which prevents the seepage of waste out of the pressure vessel  420 . The shaft  424  is supported at one end by a bearing  134 , located outside of the pressure vessel  420 . The shaft  120  of the agitating mechanism  68 , which connects to an eccentric rotating arm  430  in the pressure vessel  420 , is connected to the driver  70 , the electric motor  122  in preferred embodiment via a gear drive  124 . 
     Referring to FIGS. 17 and 18, the agitating mechanism  426  includes the shaft  120 , the eccentric rotating arm  430 , a horizontal arm  431 , and a plurality of paddles  433  each having a blade  434 . The eccentric rotating arm  430  extends from the shaft  424  towards the wall  82  and receives the horizontal arm  431   
     The paddle  433  of the agitating mechanism  68 , which each have a blade  434 , are connected to the horizontal arm  431 . The blades  434  are generally cylindrical in shape and are angle such that one side generally moves the waste in a series of planes perpendicular to the eccentric rotating arm  430  as the shaft  120  rotates in one direction. The other side of the blade are faced such that the waste is moved towards the end of the pressure vessel  420  that has the single port  422  when the shaft  120  is rotated in the opposite direction. 
     The pressure vessel  420  also has a hole  432 , as seen in FIG. 17, to which the venting/filter system  100  is connected. The pressure vessel  420  in addition has a minimum of other smaller openings for monitors or sensors, such as a pressure sensor and a temperature sensor. 
     Still referring to FIG. 17, similar to the embodiments discussed above, a heating jacket  64  in a preferred embodiment is a steam jacket and is defined by the wall  82  of the pressure vessel  420  and the outer exterior wall  86 . In addition to opening to allow access to openings in the wall  82  of the pressure vessel  420 , the outer exterior wall  86  has additional openings for allowing steam from the steam line into the space  84  in the steam jacket  64 , an opening to the steam trap for the collection of condensed steam; and an opening for the removal of trapped air in the steam jacket  64 . 
     The pressure vessel  420  has a knife edge  436  on the edge the blades  434 . The knife edge  436  interacts with a series of blocks  438  carried on the walls  82  of the pressure vessel  420 , and on the upper half of the pressure vessel  420  in one embodiment. The blocks  438  hinder rotation of the waste to allow the blades to cut the waste. 
     While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.