Abstract:
A bio-hazardous waste compactor is described which provides a negative air pressure and venting system while allowing for the filtration of the air and control of sound. The compactor contains a sealed chamber which includes a sump area in the bottom of the chamber for fluid control. Waste is weighed so that the operator knows when to remove the waste. Ultraviolet light is provided to prevent the growth of vegetative pathogenic organisms. Finally, a disposable bag to be used in connection with such a bio-hazardous waste compactor is described which has an inner porous layer, an intermediate, biocide-containing, super-absorbent polymer layer and an outer non-porous layer.

Description:
This application is a continuation of application Ser. No. 07/853,148 filed Mar. 18, 1992, now abandoned. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to an apparatus for use in medical facilities where bio-hazardous waste is collected in large volumes and must be disposed of in a safe, sanitary, and economical fashion. More particularly, this invention relates to an apparatus adapted to compact bio-hazardous waste consisting of solid, semisolid, and small amounts of liquid waste, while ensuring that such waste is sealed within the apparatus. 
     BACKGROUND OF THE INVENTION 
     In the past, most bio-hazardous waste was burned in incinerators owned by a hospital or other medical facilities. Due to current laws, a large number of rural areas cannot operate an incinerator because of the expense of maintaining the incinerator in compliance with current regulations. Rural hospitals and clinics must, therefore, contract with a waste disposal company to dispose of their bio-hazardous waste. These companies usually charge a lump sum amount per box with a maximum weight allowed. Thus the medical facility is not able to pack each box to its maximum weight. On the other hand, attempting to compact the material by hand is unsafe. 
     Trash compactors are available in the prior art which attempt in some way to filter airborne contaminants produced by the trash during compaction. For example, U.S. Pat. No. 4,008,658 to Stock et al. describes an apparatus for compacting waste material such as paper, fabrics, plastics, light metal, and so forth. In order to capture particles of dust, such as radiation-contaminated particles generated during receiving and hydraulic compacting operations, the apparatus is provided with a removable drum, a loading chamber over the drum and an exhaust system communicated with the loading chamber to draw off and filter particles of dust and other contaminants. The atmosphere in the chamber that is evacuated is replaced by an atmosphere that is drawn in around the sides of the drum. 
     U.S. Pat. No. 4,273,037 to Ruebesam describes a hydraulic trash compactor for low-level radiation applications wherein dust produced during trash compaction is removed from the compactor and filtered. The trash compactor has a base frame with vertical I-beam piston guide means supporting a rectangular piston for vertical reciprocation. The compactor also has a plurality of suction openings extending around the periphery of the piston which are connected to a vacuum source. Flexible seal flaps on the periphery of the piston engage the sides of an open-topped trash container as the piston moves into the container so that dust resulting from the compaction is removed through the suction openings to a filter box for disposal. 
     U.S. Pat. No. 5,012,732 to Fox describes a hydraulic trash compactor having a sanitary air filtration system for inhibiting the release of airborne particles beyond the confines of the cabinet. Motor driven fans create a negative pressure within the cabinet and a series of in-line filters are disposed in the air flow path for capturing airborne particles. The motor driven fans operate continuously at a low speed when the doors of the trash compactor or cabinet are closed and are switched to a higher speed when the doors are open. When the doors are closed, a continuous influx of air is provided through the interface between the closed doors and the side walls of the cabinet. 
     Finally, U.S. Pat. No. 4,407,191 to Brenner describes a weight indicator for use with a refuse compactor. Once the compacted refuse reaches a preselected weight sufficient to pivot the receptacle against the action of a spring, bellows are compressed and fluid transferred to a sight tube which indicates that the receptacle is full. Weight measurement using this system, however, will be influenced by the spatial distribution of the trash since the weight is detected based on a lever action about a fulcrum. 
     The prior art devices all have various deficiencies which make them undesirable for the routine disposal of bio-hazardous waste. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing, it is an object of the present invention to overcome the drawbacks of the prior art. 
     Specifically, it is an object of the present invention to provide a bio-hazardous waste compactor with a sealed compartment to hold a trash container in which bio-hazardous waste is compacted in disposable bags. The sealed compartment is maintained at a negative gauge pressure to prevent the escape of airborne pathogens or the aerosoling of liquids. This negative gauge pressure is maintained by a venting system which consists of air ducts, a fan, an air filter and a backdraft damper. Noise is controlled by venting the filtered air through a muffler. 
     It is another object of the present invention to provide a bio-hazardous waste compactor which safely compacts waste to a size and weight most efficient for disposing of waste. A built in set of scales alerts the medical facility that the waste in the compactor has reached the required weight. The weight is shown on a display located on the control panel. The bag of the compactor is then removed and placed into a box for shipping to a waste disposal company. 
     It is a further object of the present invention to provide a sealed compartment which is designed so that a pan is formed in the lower portion of the sealed compartment which will contain any liquid that is spilled into the sealed compartment. A drain is located at the bottom of the sealed compartment to allow spilled liquids to be easily removed from the compartment. 
     It is another object of the present invention to provide an apparatus wherein sanitation is maintained by the use of ultraviolet lights which are turned on for predetermined periods, such as thirty minutes, to kill infectious bacteria in the sealed compartment. The air filter is also part of the sanitation system of the compactor because it prevents bacteria from leaving the sealed compartment and becoming airborne. The sealed compartment also is equipped with bushings and protective sleeves to prevent bacteria from leaking through the compacting apparatus. 
     It is still another object of the present invention to provide an apparatus whereby the inside of the sealed compartment may be cleaned with disinfecting liquid solution. The disinfecting solution is then drained through the drain located in the bottom of the sealed compartment. A manual override of the compactor motor allows the compactor boot to be extended with the door open so that the compactor boot and associated protective sleeves may also be cleaned. 
     It is a further object of the present invention to provide a container for lining a receptacle in a bio-hazardous trash compactor having an outer non-porous layer and a highly absorbent polymer layer containing a biocide layered within the outer non-porous layer. A porous layer can be provided on the interior of the highly absorbent polymer layer. 
     In a hospital or any medical facility with its own incinerator, the compactor will save the facility time and money by safely compacting bio-hazardous waste, thus reducing the labor needed to transport the waste to the incinerator. The compactor makes it safer and more economical to collect and handle a potentially harmful material. 
    
    
     DESCRIPTION OF THE DRAWING FIGURES 
     FIG. 1 is a perspective view of the compactor according to one embodiment of the present invention. 
     FIG. 2 is a sectional view taken along line 1--1 of the embodiment shown in FIG. 1. 
     FIG. 3 is a sectional view taken along line 2--2 of the embodiment shown in FIG. 1. 
     FIG. 4 is a sectional view of a bio-hazardous waste compactor bag according to one embodiment of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring initially to FIGS. 1-3, the compactor (11) is housed within a metal box (30). The interior is accessible through a door (1) which covers an opening in a sealed compartment (3). A sealed compartment (3) contains a trash receptacle (2) mounted on a rack (31) on rollers (4) which allows the trash receptacle (2) to be detachably supported and reciprocally moved into and out of the opening in the sealed compartment (3). 
     The door (1) is opened by releasing a latch (33) which initially relieves negative air pressure in the sealed compartment (3). The door (1) is then opened and the rack (31) is withdrawn from the sealed compartment (3) by means of rollers (4) to allow the compactor bag (26) to be placed into or removed from the trash receptacle (2). 
     As shown in FIG. 4, the bio-hazardous waste compactor bag (26) is a disposable container designed to fit into the trash container (2) of trash compactor (11). An outer non-porous layer (41) of the bag (26) can be made from a suitable heavy duty plastic and is colored red to comply with the regulatory requirements of hospitals. An inner porous layer (42) of the bag (26) can be made of porous material, such as paper. A super-absorbent layer (43), such as that found in disposable diapers, containing a biocide, which inhibits the growth of or kills the microorganisms, is placed between the outer non-porous layer (41) and inner porous layer (42). It is believed that a suitable biocide is a NALCON brand preservative available from NALCO Chemical, No. 763, used at a 500 ppm strength. When bio-hazardous waste is placed in the bag (26) for compaction, any liquid present in the waste material passes through the inner layer (41) and is absorbed by the polymer layer (43) where the liquid is disinfected by the biocide. Once the bag (26) is full, it is removed from the compactor and disposed of by incineration. 
     Referring back to FIGS. 1-3, biomedical waste is then put into the compactor bag (26) in trash receptacle (2). The trash receptacle (2) is then moved into the sealed compartment (3) by means of rollers (4) and rack (31). Next, the door (1) is moved to a closed position where complementary sealing members (i.e., door seals (5) and case lips (6)) are engaged to ensure an airtight seal. 
     When the trash receptacle (.2) is received into the sealed compartment (3), proximity switch (29) is depressed, and a negative gauge pressure is provided as described below. A compactor motor (12), which is powered by standard 110v ac current, is then turned on which drives a small pulley (13). The small pulley (13), in turn, drives pulley belt (14) in a circular motion which simultaneously drives large pulley (15). The large pulley (15) turns screw shaft (16) which lowers a compaction assembly which includes plate (17) connected to guide posts (18) which, in turn, extend into the sealed compartment (3) where they are connected to a compaction boot (19). As the compaction boot (19) moves down, the trash in the trash receptacle (2) is compacted. Once the compaction boot (19) reaches a point of refusal, or when a bottom limit switch (34) is tripped, the compactor motor (12) reverses and the compaction boot (19) is retracted. Thus, the compaction assembly allows the compaction boot (19) to be reciprocally moved into and out of the trash receptacle (2). During the movement of the compaction assembly, protective sleeves (20) and guide post bushings (21) act to seal the points at which the compaction assembly enters the sealed compartment (3), preventing the escape of pollutants from the sealed container (3). 
     As the compaction is taking place, a fan (8), which is powered by a 110v ac current, transports atmosphere from the sealed compartment (3) and maintains negative gauge pressure therein by pulling air through air filter (10) and pushing air through duct system (9), backdraft damper (35), and muffler (22). The muffler (22) reduces the sounds made while operating. This atmosphere removal system may be engaged at any time by pressure transducer (7) when it senses a loss of negative gauge pressure. When a sudden increase in air pressure is sensed, a higher stage speed is demanded of the fan (8). When the fan (8) is not running, backdraft damper (35) closes to prevent the loss of negative gauge pressure. 
     Once the compaction cycle is complete, the unit automatically measures the weight of the waste using a scale (23) provided in the sealed compartment (3). A display (24) on control panel (25) displays the weight of the waste. When the desired weight is obtained, the door (1) is opened and the trash receptacle (2) is withdrawn from the sealed compartment(3) via rollers (4) to allow the waste contained in the compactor bag (26) to be removed for disposal. 
     When the compactor (11) is between cycles, ultraviolet lamps (27) are turned on for thirty minute cycles to further improve sterilization. The ultraviolet lamps (27) destroy vegetative pathogenic bacteria that are exposed to the ultraviolet light. 
     After the waste is removed in the compactor bags (26), the operator can override the compaction cycle and extend the guide post (18) and protective sleeves (20). The inside of the sealed compartment (3) can then be cleaned by opening the door (1) and spraying the inside of the sealed compartment (3), the extended sleeves (20), and the compactor boot (19) with a disinfectant solution. The liquid cleaner may be removed from the sealed compartment through a drain (28) which is equipped with a valve (32). If there is a spillage of fluids into the sealed compartment (3) during the compaction cycle, a pan formed in the lower portion of the sealed compartment (3) would act as a sump, thus containing the fluid and preventing its spillage upon opening the door (1). This fluid may then be removed through drain (28). 
     While the preferred embodiments of the present invention have been described, it should be understood that various changes, adaptions and modifications may be made therein without departing from the spirit of the invention.