MXPA00011846A - Apparatus and method for the disinfection of medical waste in a continuous manner - Google Patents

Abstract

An apparatus (12) and method for processing medical wastes are disclosed. Medical waste are disintegrated or shredded, disinfected with radio-frequency electromagnetic radiation and then transformed into useful material. The transformation includes the steps of continuously feeding medical waste, via a conveyor (36) into a tube (240) and heating the medical waste passing through an extruding tube (238, 242) with electromagnetic radiation (239) so as to heat and disinfect the medical waste.

Description

APPARATUS AND METHOD FOR THE DISINFECTION OF MEDICAL WASTE IN CONTINUOUS FORM BACKGROUND OF THE INVENTION The disposal of medical waste is of pressing interest because the waste can cause infection. Such infectious waste is a byproduct of medical and veterinary care. For example, regulated medical waste consists of the following categories: 1. Crops and supply materials for infectious agents and associated biological agents; 2. Pathological waste; 3. Human blood and blood products; 4. "Contaminated edged articles", including needles, syringes, razors, scalpels and broken glass; 5. Waste of animals; 6. Waste for insulation, including gloves and other disposable products used in the care of patients with serious infections; and 7. "Unfinished items". Hospitals typically segregate these categories of waste into three general groups: a) general medical waste, including the wastes mentioned above in categories 1, 2 and 3; b) veterinary waste, or category 5; and c) wastes that are predominantly plastics, including categories 4 and 6. Contaminated edged articles and waste for isolation are categories of special interest, since these wastes may have been exposed to 5 highly dangerous infections such as AIDS or hepatitis. In particular, articles with edge have aroused great public interest, when observed on beaches and other public areas. Hospitals and other generators of medical and veterinary waste use three main methods for waste management: 1) incineration of waste on site, 2) boiling of waste in steam autoclave and subsequent shipment to a landfill, and 3) processing not in situ before transporting the waste to a waste hauler. Predominantly located in urban areas, many hospital incinerators emit pollutants with a frequency relatively high. In emissions from hospital incinerators, the Environmental Protection Agency (EPA) has identified hazardous substances, including metals such as arsenic, cadmium and lead; dioxins and furans; organic compounds such as ethylene, acid gases and carbon mode; and soot, viruses and pathogens. The emissions of these incinerators may be a greater threat to public health than inadequate discharge (Stephen K.). Although boiling in a steam autoclave can be used to disinfect waste before further processing, it is expensive and tea . • J consumes time. Heat quickly inactivates viruses; however, bacteria survive a little longer than viruses. Spores of bacteria can be highly resistant to heat sterilization. To ensure effective disinfection, temperature monitoring devices, such as thermocouples and biological indicators such as the heat-resistant spores of Bacillus stearothermophilus, can be used. The patent of E.U.A. No. 2,731, 208 to Dodd discloses a steam sterilization apparatus for the disposal of contaminated waste, which crumbles the waste ("including paper containers such as spent sputum bottles", column 1, lines 28 to 29), blow steam into a container filled with shredded waste, and pour the disinfected waste into a sewer system. This procedure has several drawbacks, including the processing of only limited types of articles and disposition of the processed waste in a culvert (column 4, line 49). Certificate No. 1, 123,703 of the Soviet inventor also describes a method for sterilizing medical instruments for reuse by UHF treatment. In the case of needles for injection, it describes a final temperature of 160 ° C to 470 ° C, and in the case of acupuncture needles, it describes a final temperature of 160 ° C to 270 ° C. The patent of E.U.A. No. 3,958,936 to Knight describes the compaction of hospital waste for a more efficient disposal in landfills. Specifically, this reference describes the application of heat on the scale of approximately 204.4 ° C to 315.5 ° C to hospital and other waste to melt the plastic and convert it into a compact and hard block for a safer disposal in landfills. . The waste is disinfected, and the needles are contained in the plastic. This method has the disadvantages of requiring high energy cost to reach high temperatures and disposal in landfills. The patent of E.U.A. No. 3,547,577 to Lovercheck discloses a portable device for treating waste such as garbage, household waste and the like (column 1, lines 13 to 19). The machine crumbles waste, compresses the crumbled waste into briquettes, and sterilizes the briquettes with gaseous ethylene oxide (column 1, lines 15 to 19). After crumbling, the waste can be separated into magnetic and non-magnetic portions (column 2, lines 13 to 23). After the waste is separated in this way, only the non-magnetic portion is compressed into briquettes and sterilized (column 2, lines 23 to 25). The sterilization step uses gaseous ethylene oxide, which requires temperature control (column 2, lines 30 to 57). In this way, the briquettes are maintained at a temperature of approximately 54 ° C (column 2, line 51). One drawback of this system is that heat and poisonous gas are required to disinfect the waste. Another drawback is that when the waste stream is divided into metal, water and briquettes, only part of the waste stream (briquettes without metal or water) is disinfected. A further disadvantage is that the volume of the waste stream is limited because only one briquette is formed at a time. Another drawback is that the material is disposed in a landfill or by incineration. Although its use as a fertilizer is suggested (column 1, line 47), there is no teaching that the briquettes are really suitable for that use, or how the briquettes could be further processed for that use. Several energy sources are being considered as potential sterilants. Microwaves are increasingly being investigated for rapid sterilization of individual medical devices and shredded medical waste. Recently, an experiment showed that medical instruments could be disinfected in only 30 seconds in a microwave chamber (N.Y. Times, "Science Watch: Microwave Sterilizer is Developed" Jun. 20, 1989). One problem is that this particular method can handle only a few instruments at a time. According to a publication, a medical waste disposal system using microwaves has apparently been developed. This system shreds medical waste first, sprays it with water and spreads the small pieces in a thin layer on a conveyor belt. Then, the conveyor belt carries the mixture through a microwave chamber that heats the mixture to approximately 96 ° C.

The waste can be sent to a vaporization station, where steam is applied to inactivate the surviving microorganisms. After the disinfection step, the waste is packaged for shipment to landfills or incinerators (The Wall Street Journal, page B3, Apr. 10, 1989). In addition, microwaves show limited penetration. If they are applied to large-scale medical wastes, microwaves alone do not heat very effectively. In contrast, radio frequency (RF) waves are relatively low frequency waves that penetrate more effectively. RF waves have been used directly and indirectly for sterilization. The patent of E.U.A. No. 3,948,601 to Fraser et al, describes the indirect use of RF waves in the disinfection of a wide variety of medical equipment and hospitals, as well as human waste. This reference describes the use of RF waves to heat certain gases (particularly argon) to ionize in gaseous plasma at approximately 100 ° to 500 ° C. This reference describes that "cold" plasma (column 1, line 12), effectively sterilizes an article at a temperature of only 25 ° C to 50 ° C, and very low pressure. However, sterilization by gas plasma does not suggest the direct use of RF waves in sterilization. If the hospital first subjects or does not autoclave your medical waste, including needles and broken glass, the waste is then taken to a waste handler for transport to a land fill or other deposit. There are several problems with this disposal method. First, landfills, particularly in many urban areas, are becoming saturated. In addition, older landfills can release toxic chemical compounds into the surrounding land and contaminate the water supply. In this way, burying waste is becoming important. Likewise, unauthorized downloading may occur.

BRIEF DESCRIPTION OF THE INVENTION One aspect of the present invention relates to a method for processing medical waste, which includes the steps of continually feeding medical waste into a tube and exposing the medical waste that passes through the tube, to electromagnetic radiation to heat and disinfect the same. . A second aspect of the present invention relates to an apparatus for processing medical waste with an extruder that receives medical waste and forms a continuous tube of medical waste for feeding through a source of electromagnetic radiation. The source of electromagnetic radiation receives the continuous tube of medical waste and generates electromagnetic radiation that heats and disinfects the continuous tube to produce a continuous disinfected tube of medical waste.

A third aspect of the present invention relates to a method for reducing the ignition potential of a fire of a material that will be disinfected by radiofrequency radiation, providing a material that will be disinfected, and continuously feeding the material into a tube, where A portion of the tube is located in a radiofrequency radiation field. The material that passes through the tube is exposed to radiofrequency radiation to heat and disinfect it. Each aspect of the present invention provides an efficient apparatus and method for reducing the infectious potential of medical waste, and for transforming it into material which would not adversely impact the environment in general. The present invention provides the improved performance of medical waste per unit volume, in addition to the improved reduction of electric arc formation, ignition of fires and improvements of the radiofrequency field. Each aspect of the present invention also provides improved thermal performance by creating steam, thus preheating the material, which helps to sustain the temperature of the material. further, a preferred embodiment of the present invention allows the further processing of preselected medical and veterinary waste in recirculated plastic or waste derived fuel. Other advantages and novel features of the invention will be described in part in the following description, and in part will be apparent to those skilled in the art upon examination of the following, or may be learned by putting the present invention into practice.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a plan view diagram of a first embodiment of an apparatus for handling and processing medical and veterinary waste; Figure 2 shows a plan view diagram of a second embodiment of an apparatus for handling and processing medical and veterinary waste according to the present invention; Figure 2A shows a plan view of an alternative waste feeding system for use in the apparatus of Figure 2; Figure 3 shows schematically one embodiment of a pre-processing apparatus to be used with the apparatuses of Figures 1 and 2; Fig. 4 schematically shows one embodiment of a radio frequency heater to be used with the apparatuses of Figs. 1 and 2; Fig. 5 schematically shows one embodiment of a waste-derived fuel apparatus to be used with the apparatuses of Figs. 1 and 2; Figure 6 schematically shows one embodiment of a plastics claiming apparatus to be used with the apparatuses of Figures 1 and 2; Fig. 7 is a front view of an embodiment of an extruder to be used with the apparatus of Fig. 2; and Figure 8 is a side view of the extruder of Figure 7.

DETAILED DESCRIPTION OF THE MODALITIES CURRENTLY PREFERRED Disintegration and crushing of waste As shown in Figure 1, medical waste in sealed boxes 10 arrives at the medical waste processing facility 12, and is discharged onto a conveyor belt 14, where all the boxes 10 in each load They are segregated and counted. The conveyor belt 16 of the shredder carries the boxes 10 in the pre-processing area 18. The pre-processing area 18 contains a shredder 20 and an endless conveyor 22, which are designed to disintegrate medical waste into fragments , and move the fragments to other containers 34 for disinfection. As defined herein, "disintegration" refers to the fragmentation or comminution of materials to a relatively uniform size, which is not greater than about 3.81 cm.

As shown schematically in Figure 3, the pre-processing area 18 has several characteristics to prevent the escape of contamination from the area 18. First, the entry and exit of the medical waste in the pre-processing area 18 it is controlled by two series of air locks, inlet air locks 28 and outlet air locks 26. Each series of air locks consists of two series of doors 28, 30 and 32, 33, respectively. To enter the pre-processing area 18, the medical waste boxes 10 pass through the first series of doors 28, which are closed behind the boxes 10. After the first series of doors 28 is closed, the second series of doors 30 opens and allows the boxes 10 to enter the pre-processing area 18. The exit doors 32, 33 function in a manner similar to the entry doors 28, 30. In this way, there always exists at minus a series of closed entry and exit doors at any time. In addition to the air locks 24 and 26, the air flow is further controlled by discharge ducts 35 heated and filtered from the area. The electric heaters 37 of the conduit maintain the temperature in the conduits 35 at approximately 82 ° C, which significantly reduces the virus population. Through the conduits 35 are high efficiency particulate air (HEPA) filters 39 that have pores of 3 microns and an efficiency of 99.7% to prevent bacteria from escaping. These discharge ducts 35 of the area control the air flow in and out of the sealed pre-processing area 18. A large fan 41 expels air from these ducts 35 at the rate of approximately 304.8 m / min. This fan produces "negative" air pressure, which helps prevent possibly contaminated air from the pre-processing area 18 from flowing back to the rest of the facility 12. The filtered and heated air is vented to the outside environment. In addition to the discharge duct 35 of the area, there are filtered and heated ducts (not shown) connected to the shredder 20, the endless belt 22 and the pneumatic press 43 that vent to the outside environment in the same manner as described for the ducts. of discharge 35 of the area. As shown in Figure 3, the medical waste boxes 10 enter the pre-processing area 18 on the conveyor belt 16, and are emptied into the shredder 20. The disintegration or comminution is carried out by two series of cutting blades. cutting (not shown) that rotate at 1800 revolutions per minute, which are driven by motors of 37,300 joules / sec (not shown). The shredder 20 converts medical waste into fragments measuring approximately 3.81 cm in its largest dimension. Shredding also reduces the volume of medical waste by almost half. A suitable shredder is model No. 00-5371-D, available from Shredding Systems, Inc., Wilsonville, Oregon, which measures approximately 3.66 meters in height, 3.05 meters in width and 3.66 meters in length.

According to one embodiment, the waste fragments leave the shredder 20 by an endless conveyor 22, which operates inside a tube and which further carries the medical waste fragments vertically towards the conveyor tube 45 from which the fragments fall in the pneumatic press 43. The pneumatic press 43 compresses the fragments of medical waste into heat-resistant polyethylene plastic containers 34, which measure 60.96 cm x 60.96 cm x 45.72 cm and weigh approximately 22.7 kg. As defined herein, heat resistant means that the containers do not soften or melt during the heating process, and that the containers maintain the temperature of the medical waste within about 8 ° C when stored at room temperature (25 ° C). C) for one hour. The containers 34 include tight but not sealed caps. A suitable container is model No. 24, available from Chem Tainer, Babylon, N.Y. Each container 34 is filled with approximately 90.8 kg of compacted waste fragments. At this point in the procedure, water can be added, but usually it is not necessary. Alternatively, a foam may be sprayed onto the medical waste fragments having a high metallic content. It is thought that water and foam help to disperse heat and prevent fires. Then, a cover is fixed tightly to the filled container 34. The pneumatic press 43 also compacts fragments of medical waste to less than half the volume that the container 34 receives. Accordingly, the total reduction in the volume of the medical waste from its reception in the facility 12 to the closure of the container 34, is approximately 5 to 1. In this way, the waste entering the pre-processing area 18 with a density of 80.05 g / l leave area 18 at densities of 400.25 g / l. It can be observed that different waste, namely paper, plastics, glass, metal and fluids, are converted to the more uniform sizes and densities required by a mechanized radiofrequency (RF) heating chamber. In a second preferred embodiment, the waste is processed essentially as described above, except that the waste is not processed in separate containers. In this embodiment, as best shown in Figure 2, the medical waste is received in a collection trap 200. A material transfer device 202 is used to remove the medical waste from the collection trap 200 and place it in a hopper receiver 204. The hopper 204 discharges the waste into a waste size reduction unit 208. Within the waste size reduction unit 208, a pair of counter-feed feed control rollers 210 volumetrically measure material transfer to the initial size reduction assembly 212. The material is then converted into strips and pieces in the initial size reduction assembly 212, and then passed through a primary size reduction assembly 214 which can be any reduction device commercially available standard size (for example, shredder). The material is ground to a uniform size in the primary reduction assembly 214. The uniform size is a predetermined size that can be preset to abide by local regulations. Preferably, the waste size reduction unit 208 has a high speed wear design with variable multi-stage evacuation. Suitable waste size reduction units include open or closed rotor granulators, hammer mill type mineral crushers, wood cutters-mixers, auto shredders or adapted chippers, so that the internal wear surfaces are configured, as it is known to those skilled in the art, to explain characteristics such as the size and abrasion resistance of the material that will be processed. In another embodiment, as shown in Figure 2A, medical waste can be received in containers 201 on an approach conveyor 203. Waste containers 201 pass over a parking area 205 having a scale, radiation detector and detector. of hydrocarbons, and proceed in a receiving hopper 207. The waste is discharged from the containers 201, and transported by double endless conveyors 209 to the hopper 204 in the waste size reduction unit 208. A primary fan 216 maintains the hopper 204 and the process of reducing size under negative pressure to prevent aerosols from escaping from the waste processing equipment. The primary fan is preferably at least one high pressure fan of 3525 l / sec, which produces a total static pressure of 40.64 cm -50.8 cm (column of water). Other fans and pressures can also be used. Consecutive of the size reduction process of the waste size reduction unit 208, the material is transferred to a high velocity air flow along a tube 215 towards a primary low energy cyclone 218 which uses centrifugal force to Separate the material from the high velocity air flow. The high-speed transport air passes through the primary fan 216 in a high-energy primary cyclone 220 that removes fugitive dust particles and deposits them on the sealed material conveyor belt 222. The transport air then passes along the a powder transfer conduit 224, and leaves the processing area through a dust control unit 225 after three more stages of filtration and an odor control step. The powder control unit may be any commercially available standard bag or cartridge filter unit. The material transport conveyor 222 carries the shredded waste processed by the high and low energy primary cyclones 218, 220, to a secondary waste size reduction unit 226 to crush the material into more uniform pieces. A secondary fan 228 generates a high velocity air flow that pushes the shredded material through a transfer tube 234. A secondary low-energy cyclone 230 and a secondary high-energy cyclone 232 remove the fugitive dust particles from the air flow. Of high speed. The high-speed airflow generated by the second fan passes through a powder transfer conduit 235. The powder transfer conduit 235 leads to a secondary dust control unit 237. The secondary size reduction unit 226 and the control of powder 237, can have the same construction as the primary unit of size reduction 208 and dust control unit 225, respectively.

The high-energy cyclones 220, 232 connect each to a respective powder transfer conduit 224, 235 feeding into a respective powder control unit 225, 237. The dust control units 225, 237 preferably include three filtration steps (not shown), a dust filter cleaning continuous, a HEPA prefilter and a HEPA filter bank. These filters remove particulate matter from the air that leaves the waste processing facility. The effectiveness of the different air control devices is preferably: Device efficiency% Primary cyclone low energy 90% > 20 microns Primary 95% high energy cyclone > 10 microns Low-energy secondary cyclone 90% > 20 microns High energy secondary cyclone 95% > 10 microns Prefilter HEPA 95% > 5 microns Continuous cleaning dust filter 9 999..999999 %% > 1 miera HEPA Filters 99.9999% > 0.12 micras where the efficiency percentage defines the percentage of larger particles of a given size that are removed from the air.

The finely ground waste material, the collected dust and the process waste water, which can be produced, are deposited on a material conveying conveyor 236 which transports the material to a high density extruder 238. The extruder 238 compresses the fragments of medical waste moistened, and concurrently pushes the compressed waste into a fixed tube 240 for disinfection. The tube 240 is preferably constructed of a rigid mixed material. A suitable mixed material is glass E winding in filaments included in a fire resistant resin. The extruder 238 performs mechanical multi-stage, and preferably two-stage, mechanical compression of the waste, such as through cylinder and piston assemblies. The extruder 238 is preferably constructed of abrasion resistant steel. Referring to Figures 7 and 8, a hopper 237 receives the waste materials from the conveyor belt 236, and deposits them in the extruder 238. The extruder 238 has two compression chambers for compressing the waste material in two stages. The primary compression stage 242 is located in a vertically oriented chamber. The primary compression stage 242 increases the waste density by approximately 2: 1. A piston cylinder suitable for the primary compression stage 242 is a series N5 hydraulic cylinder, model N5R-3.25 x 23-C-1.75-2-S-H-R-1-1, available from Hydro-Line. The final compression stage 243, located horizontally at the end of the throat 244 of an extruder, compresses the waste a second time, and continuously press the waste through the throat 244 of the extruder. The final compression stage increases the density of the compressed material of the primary stage by about 2-3: 1, so that the total compression after the final stage is 4-6: 1. A series hydraulic cylinder N5S-5 x 62-C-3.5-2-FJR-1-1-XN5 from Hydro-Line can be used for the second compression stage 243. The fully compressed waste is continuously pressed through the throat 244 of the extruder, and exits at an outlet end 246. The throat 244 of the extruder feeds directly into the fixed tube 240 which is located in the dielectric heater (Figure 2). The advantages of using the extruder 238 and the fixed pipe 240 include the improved use of energy by improved dielectric coupling, reduction of the possibility of fire due to the reduced air content of the waste, and improved dielectric efficiency by the generation of a dielectric constant more uniform in the waste material. Also, because the occurrence of air pockets in medical waste is reduced, the dielectric constant thereof is increased.

Disinfection In the first embodiment, as shown in Figure 1, the sealed containers 34 of the medical waste fragments are transported from the pre-processing area 18 and in the dielectric heater 38 for volumetric heating by electromagnetic radiation, such as radiation radiofrequency (RF). The containers 34 of compacted medical waste fragments enter the dielectric heater 38, and thus through an inlet tunnel 40. The dielectric heater 38 generates RF waves, which heat the waste as described above. The waste fragment containers are heated uniformly or volumetrically in the electric field for approximately 5 minutes. As a result of this exposure to RF waves, the waste reaches temperatures of approximately 90 ° -100 ° C. The covered containers 324 are moved along a conveyor belt 36 in the dielectric heater 38 which measures 11.59 m in length, 3.96 m in width and 3.05 m in height. The dielectric heater weighs 12712 kg. Two tunnels 40 and 42 of 2.44 m form the inlet and outlet portions, respectively, of the dielectric heater 38. The tunnels attenuate the RF waves, and prevent RF leakage from the dielectric heater 38. In the RF chamber of 6.1 In furnace 44, a system of exciter electrodes and grounding 46 generate electromagnetic waves in the RF band. The RF band is between the audio and infrared frequencies, and includes approximately 10 kilohertz (kHz) to 300 gigahertz (GHz). When the electrode system 46 is supplied with radiofrequency energy, it projects an electromagnetic wave into the target medical waste containers 34. In the second preferred embodiment, as shown in Fig. 2, the compressed medical waste fragments are disinfected according to the extruder 238 and pushes them stably through the fixed tube 240. After disintegrating the medical waste and compressing it in the extruder 238 , the extruder pushes the compressed medical waste fragments into the first end of the tube 240. The tube 240 extends from the extruder 238 through the dielectric heater 239, and out of the outlet end of the dielectric heater. In one embodiment, the incoming end of the tube 240 may be 30.48 cm in diameter. This diameter increases a constant amount by distance in length of the tube 240. In one embodiment, the diameter increases a constant amount approximately between 1,041 cm / m to 4,166 cm / m in length of the tube. The waste is continuously pushed through the tube 240, and is moved along it through the dielectric heater 38 for volumetric heating by RF waves. The compacted medical waste fragments enter the dielectric heater 239 through the tube 240. The dielectric heater 239 generates RF waves, which heat the waste as described above. The waste fragments move at a constant speed through the tube 240, and thus through the heater. The waste is heated uniformly or volumetrically in the electric field for approximately 3 to 10 minutes, depending on the intensity of the electric field. The time that the waste remains in the electric field is designated so that the waste reaches temperatures of approximately 90 ° C-100 ° C as a result of exposure to RF waves. Accordingly, the constant velocity with which the waste is pushed through the tube 240 can be adjusted based on the size and intensity of the field generated in the dielectric heater. Preferably, the dielectric heater exposes the tube of compressed medical waste fragments to an electric field that oscillates at 11 megahertz (MHz) and has a field strength of 50 kilovolts per meter (kV / m). The fixed tube is transparent to the electromagnetic radiation of the dielectric heater, so that the RF waves effectively penetrate the mixed material of the fixed tube 240, and substantially all of the energy is absorbed by the waste tube. An advantage of using a fixed tube of mixed material located in the dielectric heater, rather than the use of multiple containers constructed of a polyethylene material, is that the tube can have a longer service life than the containers 34. In addition, the tube allows the continuous real processing of medical waste, rather than a constant intermittent procedure. Without being limited to any particular theory, it is thought that, for the modalities of figures 1 and 2, RF radiation transfers energy directly into materials, mainly through the interaction of their electric fields variable in time with molecules, to produce heat which induces dipole rotation and molecular vibration. You can generate waves or RF radiation by connecting an alternating current of RF to a pair of electrodes. Between the electrodes, an alternate RF electromagnetic field is established which has a time varying electric field component. When objects are placed between the electrodes in the time-varying electric field, the time-varying electric field partially or completely penetrates the object, and heats it. Heat is produced when the time-varying electric field accelerates ions and electrons that collide with molecules. Heat is also produced because the time-varying electric field causes the molecules, and particularly those with a relatively high electric dipole moment, to rotate back and forth as a result of the torque placed on them by the variable electric field in weather. Most large molecules or molecules with uniformly distributed charges have relatively low or non-existent dipole moments, and are not affected to a large extent by the time-varying RF electric field. The small molecules, particularly the polar groups, have relatively large electric dipole moments, and thus have relatively long torques exerted on them by the time-varying electric field. In particular, highly polar molecules such as water undergo relatively long torques and, as a result, are rotated by the time-varying electric field. The mechanical energy of rotation is transferred to the surrounding materials as internal energy or heat. The lower frequency variable electric fields penetrate deeply and heat the objects more evenly. The variable electric fields in time of relatively high frequency do not penetrate so deeply, but heat faster the portions of the objects with which they interact. Because different materials are composed of different types of molecules with different electric dipoles, they are heated at different speeds when exposed to a given RF field. For example, plastics, which are composed of very large molecules (polymers), are not heated by RF fields as quickly as water. Metal objects may or may not be easily heated when exposed to RF fields, because their high conductivity tends to reduce electrical fields and disperse them. As a result, there are many conditions under which metallic objects are difficult to heat. On the other hand, said RF fields can also induce substantial current flowing on the outside of the metal objects. Under certain circumstances, heating effects will occur on the surface of the metallic object which, in the case of a small needle, the heat is diffused rapidly in the interior. In addition, the presence of thin and long metal objects in an electric field causes an increase in the intensity of the electric field near the ends of these metallic objects., and a decrease or darkening of the fields near the middle part. In this way, if the electric field is parallel to the axis of the metallic object, there will be strong electric fields near the tips, and there will be weak electric fields near the center of the rod or needle.

Such field intensifications can lead to electric arcing and possible fires. When RF waves are absorbed in both modes of Figures 1 and 2, they can cause differential heating. Metal objects and wet articles in containers 34 or tube 240 absorb more waves and can create "hot spots" or uneven heating; however, before the disintegration and compaction of the medical waste fragments, the formation of a serious electric arc is avoided and the heat transfer is accelerated. In container 34 or tube 240, the vapor and heat of the hottest fragments are rapidly redistributed to all contained medical waste. Since the containers 34 are not watertight, and the tube 240 is open at both ends, the steam escapes gradually, and there is no excessive buildup of pressure. In the second embodiment of Figure 2, the medical waste continues along the tube 240 after passing through the dielectric heater 239. After leaving the dielectric heater 239, the disinfected medical waste tube emerges from the fixed tube 240 on a conveyor belt 248 that deposits the disinfected waste in a container 250. Subsequently, the disinfected waste continues to the other stations for further processing as described in more detail below. Alternatively, the waste tube emerging from the outlet end of the fixed pipe 240 may be maintained in an area or other area containing space (not shown) for cooling to room temperature before further processing as described below. As shown in Figure 4, the dielectric heater 38, 239 for the embodiments of Figures 1 and 2, has the following components: a generator 48, an applicator 49 and controls 50. The generator 48 has a power source 52, voltage controls 54 and a radiator source 56. The generator 48 measures 4.42 m in length, 1.06 m in width and 2.135 m in height. It is made of 10 gauge steel and aluminum with a 10.16 cm channel band a 635 cm thick steel bplate. The generator 48 has two compartments with doors that are airtight. These compartments contain the power source 52 and radiator source 56. The power source 52 and the voltage controls 54 provide high voltage direct current to the radiator source 56. Preferably, the generator 48 generates from about 50 to about 150 kilowatts of energy. More preferably, from about 100 to about 150 kilowatts of energy are generated. The power source compartment 52 includes a three-ph300-kw power transformer (not shown), which converts alternating current from 60 cycles to direct current, as well as six stacked silicon diode rectifiers or other equipment (not shown). The radiator source 56 generates high frequency energy. Preferably, the frequency is on the scale of about 5 to about 10 MHz. More preferably, the frequency is on the scale of about 5 to about 25 MHz. Most preferably, the frequency is about 13 MHz when the individual containers are used 34 (Fig. 1), and approximately 11 MHz when the fixed tube 240 is used (Fig. 2). An oscillator (not shown) is preferred for generating the high frequency energy, although an amplifier (not shown) can also be used. A suitable oscillator is model No. 3CW150000 of Eimac (Division of Varian, 301 Industrial Way, San Carlos, Calif.). An alternative for this purpose is the oscillator model No. RS3300CJ Siemens, which is available from Siemens Components, 186 Wood Avenue, Islin, N.J. The radiator source also has a water supply (not shown) of about 1575 l / sec at about 20 ° C for cooling. A coaxial cable 58 feeds high frequency energy from the radiator source 56 in the heater applicator 49. The heater applicator 49 consists of an adapter network 60 and electrode system 46, and is located in the furnace 44 which is a portion of the dielectric heater 38. The furnace 44 which is 6.1 m in length, 3.96 m in width and 3.05 m in height, is constructed of steel or aluminum plate of .635 cm and steel or aluminum sheet of caliber 10. The main body of the electrode system 46 is an aluminum electrode of 2.135 m by 4.27 m, whose height is adjustable from 71.12 cm-101.6 cm by means of a reversible gear motor ( not shown). The motor is operated with a 3-position selector switch on an external control panel 50, which also shows the electrode height. The heater elements 61 are installed in the electrode 46 with a suitable RF pre-filter network (not shown) for decoupling the electrode heaters 61 from the remainder of the RF circuit. The balancer network 60 has a metric relay and amplifier (not shown) which, in combination with a variable motor capacitor (not shown) automatically maintains the power output at a preset level that is uniform throughout the oven 44 The coaxial cable 58 of the radiator source 56 connects the balancing network 60 which in turn supplies power to the electrode 46 to convert the RF electricity into an RF magnetic field.

PROCESSING OF USEFUL MATERIALS The disinfected waste of the modalities of figures 1 and 2 are immediately converted into useful materials, fuel derived from waste or separated into useful components such as plastic. As shown in Figure 5, the disinfected waste, after leaving the exit tunnel 42, is emptied from the heating containers 34, or alternatively emptied from the outlet end 241 of the fixed pipe 240, in a sorting system of 300 dry waste such as the Steri-Fuel ™ recovery system available from STERICYCLE, Inc. of Deerfield, Illinois. The waste entering the dry waste sorting system 300 is placed in a receiving hopper 302 and transported by means of a normal advancing conveyor belt 304 to a triple cover vibrating filter 306. All the dust found in the waste transported on the normal feed conveyor belt is removed and taken to a dust collection unit 307 by means of a dust transfer fan 309 using a cyclone 311 placed on the normal feed conveyor belt 304. A fan 308 positioned adjacent a normal feed conveyor belt 304 feeds an air sorting system 310 that separates the light particles from the heavier dry waste material. These materials are taken to intermediate storage hoppers. The remaining material passes through a triple cover vibrating filter 306, which can be a layered filtering device having three progressively thinner, stacked filters with a certain degree of spacing to each other (the thicker screen up to the top). ), the filters finely grind the dry waste and direct the finely ground waste to a storage container 313. The largest dry waste is taken to a reduction mill 314 to further reduce the size of the waste. The reduced dry waste is transported by air to the cyclone 311 and again processed through the system 300. The dry waste processed after temporary storage in the intermediate storage hopper 312 is processed to create bales or nodes with the dry waste. The packer or pelletizer is a large compressor device 315 that compresses waste into a dense cube that can be tied with bundle 66 cables or as fuel pellets. These dense cubes or fuel nodules derived from waste leave the installation 12 and are transported to high temperature combustion apparatuses such as cement kilns (not shown). In one embodiment, when the compression medium is a baler, the baler can be 457.20 cm long, 127 cm wide and 193 cm high. It must receive power from an electric motor of 15 horsepower (not shown) that can generate a pressing weight of 3178 kg. The packer is filled with compressed disinfected waste fragments into a dense cube measuring 0.915 m by 1.83 m by 0.76 m. Each bucket is secured with four thin cables to pack 66. Each packed bucket weighs 544.8 kg. A fork lift (not shown) loads the cubes packed in trucks for transport to regional cement kilns. In another embodiment, when the compression device 315 is a pelletizing device, the appropriate pelletizer should be approximately 6.1 m in length by 1.22 m in width by 1.22 m in height. Any of a number of standard electric motors can be used to drive a compressor mechanism capable of producing compressed waste nodules with a diameter of 0.63 cm to 1.9 cm and a length of 1.27 cm to 2.54 cm. Other sizes and shapes of nodules are also suitable. Laboratory analyzes (tables A, B, C and D) have shown that these processed medical wastes, whether packaged or pelleted, have a value of approximately 27,949.21 joule / gram (table A), compared favorably with the value of coal, which varies from approximately 25,586 to 34,890 joules / gram. The sulfur content of the processed medical waste is less than 0.2% (Table A), and is lower than that of the carbon, which can vary from about 0.3% to about 4.0%. The following table D illustrates some characteristics of typical combustion for medical waste.

TABLE A Results of combustion of processed medical waste (Gabriel Laboratories, Inc.) TABLE B Mineral ash analysis of processed medical waste (Gabriel Laboratories, Inc.) TABLE C Laboratory analysis of processed medical waste (National Environmental Testinq. Inc.) TABLE D Volatile Compounds of Medical Burned Waste (National Environmental Testinq, Inc.) TABLE D (CONTINUED) RECOVERY OF PLASTICS Another way to transform the fragments of disinfected medical waste generated in the modalities of figures 1 and 2 into useful material is by means of the recovery of plastics. The recovery of plastics is preferably carried out in a wet sorting system 301 illustrated in Figure 6 after the waste has gone through the dry sorting system 300 described above with reference to Figure 5. After having passed through the Dry sorting system, the waste stream mainly carries various types of plastic materials. The wet classification system also classifies the types of plastic to filter the least useful plastic and retain the most valuable plastics to recover them. As shown in Figure 6, a first conveyor belt 320 carries fragments of an intermediate hopper containing wastes that have been processed by the dry sorting system shown in Figure 5 and the high residual density material is filtered in a heavy dump. collector 322. A second conveyor belt 324 carries the remaining fragments to the first of a series of water removing units 328 and fine particle removal units 330. The 328 water removal units each take the major plastic particles in the stream of waste and classify the different types of plastics (and other materials) for their buoyancy in liquid. The fragments having a specific gravity falling on a predetermined scale are sent to the next water removing unit 328. The fragments falling outside the predetermined scale are skimmed off the liquid and disposed of in a fines removal unit 330 or , the denser materials are removed from the bottom of the water removal unit. This separation process is highly effective for selecting the desired plastics such as polypropylene. The non-polypropylene materials removed in this process can be sent directly to a compression device 346. The polypropylene arising from this multi-stage wet classification system can be at most 99.99% pure polypropylene and continuous to be processed. Once the polypropylene fragments pass through the final stage of water removal, they are hot washed in a washing machine 334 and processed in a dryer 340 which removes all the moisture present in the fragments. The dried polypropylene sheets are ready to be pelletized and converted into items such as garbage cans, recycling bins and disposable blades. Suitable water removal units from plastics, washers and dryers can be obtained from any of the manufacturers of commercial plastic recycling equipment. In one embodiment of the invention, the recovery process is stopped after the hot washing step carried out by the hot washer 334. At this point, the plastics relatively lack of non-plastic elements and can be dried and stored as lamellae in a unit of storage of lamellas 342 for resale later. In another embodiment, the lamellae are further processed, first, by transferring the lamellae to a storage hopper 344 and then transferring them to a compressor device such as a pelletizer 346. The above descriptions of the preferred embodiments of the present invention have been presented for of illustration and description. They are not intended to be exhaustive or to limit the invention to the forms shown, and obviously many other modifications and variations are possible within the field of the previous teachings. The modalities were chosen and described to explain as best as possible the principles of the invention and their practical applications, thus allowing other experts in the art to use the invention in the best way in its various modalities and with various modifications as required for its particular use contemplated. It is intended that the field of the invention be defined by the following claims, including all equivalents.

EXAMPLES EXAMPLE 1 Mixed medical waste was crushed and compacted in accordance with the first embodiment of the present invention and placed in plastic containers 100 made of polyethylene plastic, measuring 60.96 cm by 60.96 cm 45.72 cm and weighing 22.7 kilograms be filling. Each container was divided into four quadrants, in which probes were placed sensitive to temperature. The temperature-sensitive tip of each probe was inserted to a depth of approximately 5.08 cm, which was considered the "coldest" point in the waste container and the least likely to reach the required temperature during the passage through the dielectric heater . The caps were then secured on top of the containers. Each container was exposed to RF radiation at the frequency of 13 megahertz and an electric field strength of 50,000 volts per meter approximately 5 minutes. The temperatures were recorded and tabulated as shown below: Temperature frequency distribution (° C) Scale (° C) Count Percent From 85 to 90 0 0 From 92 to 95 51 51 From 95 to 100 47 47 From 100 to 105 2 2 These statistics illustrate the uniity of warming, despite the diverse nature of medical waste.

EXAMPLE 2 Approximately 60 plastic containers were filled with about 90.8 kg of medical waste that had been crushed and compacted in accordance with the first embodiment of the present invention. The plastic containers were made of polyethylene plastic, and measured 60.96 cm by 45.72 cm and weighing 22.7 kg be filling. In each container, test tubes were placed at a depth of approximately 5.08 cm containing viruses and controls. HE adjusted temperature sensitive indicators at the top and bottom of each test tube. Then a lid was fitted to each container. The viruses used the study were herpes simplex virus (HSV), type 2, (ATCC VR-540) and Poliovirus 3 (ATCC VR-193). To ensure a homogeneous and adequate supply of virus the study, HSV and poliovirus supply materials were cultured be the start of the test, harvested, frozen and validated according to normal methods. The medical waste containers were divided into eight treatment groups as shown below: Group Time in dielectric heater Waiting time (min) (min) 1 4 0 2 4 20 3 10 0 4 10 20 5 6 0 6 6 20 7 8 0 8 8 20 The control of virus test tubes was carried out at room temperature (approximately 25 ° C) while the medical waste containers with test virus were subjected to sufficient RF radiation to raise the temperatures of the containers to approximately 60 ° C. Immediately after the waiting period (additional time at room temperature), the containers were opened and removed the virus tubes and all the tubes were sent to the microbiology laboratory. Temperature tapes were removed and temperatures recorded. On all occasions except three, the temperature exceeded 60 ° C; and at least one of the exceptions seemed to be due to the evil operation of a temperature tape. To determine the success of disinfection, viruses in the tubes of test were first diluted several times. An aliquot of each dilution was tested to see its ability to kill cells, in accordance with normal methods. Only HSV and poliovirus from control tubes (which were not subjected to dielectric heating) showed a subsequent ability to kill cells, even when diluted by a factor of 105. No HSV or poliovirus from the heated tubes (groups 1 to 8) they showed no ability whatsoever to kill cells, even when diluted by only a factor of 10. In this way, the virus validation study showed that the procedure of the first modality completely and unily destroys viruses even when the waste only heats up to approximately 60 ° at 70 ° C and kept at said temperatures only approximately 10 to 30 minutes. Because the dielectric heater of the present invention heats medical waste from 90 ° to 98 ° C, there is a wide margin of safety viral elimination.

EXAMPLE 3 Five medical waste containers each filled with approximately 90.8 kg of medical waste fragments were selected in accordance with the method of the first embodiment of the present invention and the caps were removed. Five spore strips of Bacillus subtillis var, niger were placed in each container. The spore strips were placed on the waste fragments, at the point of contact between air and waste. This is the region of the waste container that is less likely to retain heat, because hot waste gives up heat to cooler air at this point. Each spore strip contained approximately one million spores (106). B. subtilis were chosen because they are highly resistant to heat treatment. The caps were repositioned to medical waste containers and four of the five containers were passed through the dielectric heater according to the method of the present invention. The fifth waste container did not pass through the dielectric heater and served as control for the experiment. Each of the four containers passed through an electric field of 50,000 volt / m. The time of permanence, or that the containers passed in the electric field, was 5 minutes. The frequency of radio waves was 13 megahertz. As soon as the containers left the dielectric heater, temperature probes were placed in the four quadrants of each waste container to record the initial temperatures, which were averaged. After waiting for one hour at room temperature (approximately 25 ° C), the first container was opened, the internal temperature was recorded and the spore strips were removed. After waiting for two hours at room temperature, the second container was opened, the internal temperature was recorded and the spore strips were removed. The third and fourth containers opened after three and four hours, respectively, and were handled in the same way. In accordance with the normal method, the spores were diluted and cultured with the following results: Temperature Initial Start Time Concentration of Wait Reduction (° C) (° C) Spores of (hours) logarithm 1 98 92 8.5 x 10 ^ 4 2 97 92 6.0 x 10 5 3 100 84 9.0 x 10 5 4 95 81 7.5 x 10 5 Control NA NA 1 x 106 0 This test shows that the exposure of the containers of waste to RF radiation for five minutes is enough to produce a reduction of four logarithms with only one hour of waiting and reductions of five logarithms with longer waiting times. Further, while the containers remained closed, heavy containers of 22.7 kg lost only approximately 4 ° C to 8 ° C per hour when the containers were in an environment of 25 ° C. Since non-vegetative bacteria (no spores), yeasts and fungi are all less resistant to heat than spores B subtills, these organisms could be effectively removed with the treatment according to the present invention. i ...

Claims (4)

1. NOVELTY OF THE INVENTION CLAIMS 1. - A method for processing medical waste comprising the steps of: continuously supplying medical waste to a tube; and exposing the medical waste that passes through the tube to electromagnetic radiation to heat and disinfect medical waste.
2. 2. The method according to claim 1, further characterized in that the electromagnetic radiation comprises radiofrequency radiation.
3. 3. The method according to claim 1, further characterized in that it comprises the step of compressing the medical waste inside the tube.
4. 4. The method according to claim 3, further characterized in that the compression step is carried out before the continuous supply step. 5- The method according to claim 3, further characterized in that the compression step comprises performing an initial compression of the medical waste and performing at least a subsequent compression of the medical waste. 6. The method according to claim 3, further characterized in that the compression step comprises the step of simultaneously extruding the medical waste in the tube and compressing the medical waste. 7. The method according to claim 6, further characterized in that the phase of simultaneously extruding the medical waste further comprises the step of extruding the medical waste into a tube having a first end and a second end, the tube having a diameter which increases from the first end to the second end. 8. The method according to claim 3, further characterized by the step of separating disinfected articles from the disinfected medical waste tube for plastics and other useful components for recycling. 9. The method according to claim 8, further characterized by comprising the steps of: placing the disinfected articles of the tube near a magnet that removes the metal fragments and leaves the non-metallic fragments; reduce non-metallic fragments to non-metallic pieces no larger than .31 cm; subject the non-metallic parts to a flow of hot air to separate the plastic parts; and wash the plastic parts with hot water to remove paper and ink. 10. The method according to claim 1, further characterized in that the exposure step comprises exposing the tube to electromagnetic energy before exposing medical waste to electromagnetic energy. 11. The method according to claim 2, further characterized in that the exposure step comprises exposing the tube to radiofrequency energy before exposing the medical waste to radiofrequency energy. 12. An apparatus for processing medical waste comprising: an extruder that receives medical waste and forms a continuous tube of medical waste to supply through a source of electromagnetic radiation; and a source of electromagnetic radiation that receives the continuous tube of medical waste, generating the source of electromagnetic radiation an electromagnetic radiation that heats and disinfects the continuous tube to produce a continuous disinfected tube of medical waste. 13. The apparatus according to claim 12, further characterized in that the source of electromagnetic radiation mainly generates radiofrequency radiation. 14. The apparatus according to claim 12, further characterized in that the extruder further comprises a tube formed by a first end and a second end, the tube having an increasing diameter, characterized in that the diameter is greater at the second end than at the first end. 15. - The apparatus according to claim 13, further characterized in that the first end of the tube is located in an electromagnetic source inlet and the second end of the tube is located in an electromagnetic source outlet. 16. The apparatus according to claim 13, further characterized in that the first end has a diameter of 30.48 cm. 17. The apparatus according to claim 13, further characterized in that the diameter of the tube increases by .63 cm per 0.305 meters from the first end of the tube to the second end of the tube. 18. The apparatus according to claim 13, further characterized in that a portion of the tube is fixed within the source of electromagnetic radiation. 19. The apparatus according to claim 18, further characterized in that the portion fixed to the source of electromagnetic radiation is between the first and second ends of the tube, where the extruder pushes the medical waste to the tube and radiation source electromagnetic 20. The apparatus according to claim 19, further characterized in that the source of electromagnetic radiation mainly generates radiofrequency radiation. 21. - The apparatus according to claim 12, further characterized in that it comprises a first conveyor belt for transporting the medical waste to the extruder. 22. The apparatus according to claim 12, further characterized in that it comprises a first conveyor belt device for transporting the medical waste to a compactor device, further characterized in that the compacting device compacts the medical waste to produce compacted medical waste. 23. The apparatus according to claim 22, further characterized in that the compacting device is coupled to the extruder, and further characterized in that the continuous medical waste tube comprises a continuous tube of compacted medical waste. 24. The apparatus according to claim 22, further characterized in that the compacted medical waste tube comprises compressed medical waste compressed within a fixed tube constructed of a mixed material. 25. The apparatus according to claim 24, further characterized in that the tube of mixed material is transparent to the electromagnetic radiation, wherein the medical waste compressed in the tube receives substantially all the radiation falling on the tube. ^ - ^ J,; 26. - The apparatus according to claim 25, further characterized in that the electromagnetic radiation is mainly radiofrequency radiation. 27. The apparatus according to claim 24, further characterized in that the mixed material comprises glass wound in filaments included in a fire resistant resin. 28.- A method to process medical waste that includes the steps of: supplying medical waste; extrude medical waste continuously into a tube; expose the Medical waste that continuously passes through the fixed tube to electromagnetic radiation to heat and disinfect medical waste in the tube; and separating medical waste from the tube in metals, plastics and other materials for recycling purposes. * 29. The method according to claim 28, further characterized in that the electromagnetic radiation is mainly radiofrequency radiation. 30. The method according to claim 28, further characterized in that it comprises the step of compressing medical waste in compressed medical waste before extruding the medical waste in the tube. 31. The apparatus according to claim 30, further characterized in that the compression and extrusion steps are carried out simultaneously. 32. - The method according to claim 28, t further characterized in that the separation step comprises the * transfer of disinfected medical waste from the tube to a device for compaction of disinfected medical waste. The method according to claim 30, further characterized in that it comprises the steps of: compacting the disinfected medical waste and tying the disinfected medical waste with cable. 34.- A method to reduce the arcing of a material 10 to be disinfected by radiofrequency radiation which comprises the steps of: providing a material to be disinfected; increase the dielectric constant of medical waste; exposing medical waste to radiofrequency radiation to heat and disinfect medical waste. • 35.- The method according to claim 34, »15 further characterized in that the phase of increasing the dielectric constant of medical waste comprises the reduction of air pockets in medical waste. 36. The method according to claim 34, further characterized in that the material is medical waste. 37. The method according to claim 41, further characterized in that the material is metallic. 38.- The method according to claim 35, further characterized in that the step of reducing the air pockets in the material comprises the steps of compressing the medical waste and simultaneously extruding the compressed medical waste in a tube. 39.- A method to reduce the ignition of a fire of a material that is to be disinfected by radiofrequency radiation, which comprises the steps of: providing a material to be disinfected; continuously supplying the material to a tube, further characterized in that a portion of the tube is placed in a radiofrequency radiation field; expose the material that passes through the tube to the radiofrequency radiation to heat and disinfect the material. The method according to claim 39, further characterized in that it comprises the step of compacting the material to form a compacted material before the step of continuously supplying the material to the fixed tube. 41.- The method according to claim 39, further characterized in that the material is medical waste. 42. The method according to claim 39, further characterized in that the material is metallic. 43.- The method according to claim 40, further characterized in that the exposure step comprises the passage of the compacted material through the tube and the exposure of the tube and the material to the radiofrequency radiation. 44. The method according to claim 39, further characterized in that the tube is made of a mixed material. 45. - The method according to claim 39, further characterized in that the exposure step comprises the exposure of the tube to radiofrequency radiation and the transmission of substantially all the radiofrequency radiation through the tube in order to expose the material found inside him. 46.- A method to reduce the improvement of the radiofrequency field in a material to be disinfected by radiofrequency radiation, which comprises the steps of: providing a material to be disinfected; compact the material to form a compacted material; Extrude the compacted material in a tube; continuously supply the compacted material to a tube and expose the compacted material to radiofrequency radiation to heat and disinfect the compacted material as it passes through the tube. 47. The method according to claim 46, further characterized in that the material is medical waste. 48. The method according to claim 46, further characterized in that the material is metallic. 49. The method according to claim 46, further characterized in that the exposure step comprises exposing the tube to radiofrequency radiation and transmitting substantially all of the radiofrequency radiation through the tube to expose the material encountered. inside him.