Patent Application
20100278688
The present disclosure generally relates to the field of waste disposal, and more particularly, to containerized systems and methods for providing medical waste processing.
The term “medical waste” is a generic term commonly used to describe medical infectious and non-infectious waste, including waste categories such as (1) cultures and stocks of infectious agents and associated biologicals; (2) pathological wastes; (3) human blood and blood products; (4) contaminated “sharps”, including needles, syringes, blades, scalpels, and broken glass; (5) animal waste; (6) isolation waste, including gloves and other disposable products used in the care of patients; and (7) unused “sharps”.
It has been reported that the amount of waste generated in U.S. hospitals is approximately 6,670 tons per day, or about 1% of the 158 million tons of municipal solid waste produced annually. It has been further reported that 15% of the total waste generated by hospitals (over 1,000 tons daily) can be regarded as medical waste. While hospitals can be considered the primary medical waste producer, the aforementioned figures capture only a fraction of the healthcare facilities that generate medical waste. For example, currently there are approximately 180,000 private physicians' offices, 98,000 private dentists' offices, 38,000 veterinarians'offices, 15,000 medical clinics, 12,000 long-term care facilities, 4,000 laboratories, and 900 free-standing blood banks. The proper disposal of these facilities' waste is of particular concern because medical waste may be contaminated with dangerous microorganisms of infectious diseases. As such, medical waste must be sterilized before disposal in a landfill, for example.
In the past, individual facilities have handled the sterilization and/or processing of their medical waste with on-site systems. Thus, each facility dedicated valuable square-footage in housing the processing equipment and other related areas throughout the facility, such as storage areas, loading areas, transportation areas, and collection areas. Also, these individual facilities incurred great expense in the construction, maintenance, repair and operation of the processing equipment and in the staffing associated with performing the treatment processes. Facilities without on-site medical waste treatment systems also incurred great cost related to the hauling away, processing, sterilization and/or disposal of their medical waste.
One piece of equipment commonly used by both on-site and off-site waste processing systems is an autoclave. An autoclave is a device that uses steam to sterilize medical waste and other objects prior to disposal in the standard municipal solid waste stream. Autoclaving has grown as an alternative to incineration due to environmental and health concerns raised by combustion byproducts from incinerators, especially from the small units which were commonly operated at individual medical facilities. The terms “autoclave” and “autoclaving” are used to describe a machine or process in which elevated temperature and pressure are used in processing unsterile materials into sterile materials.
As the goal of autoclaving is to achieve sterility, it is very important to ensure that all of the air in the autoclave vessel is removed. Hot air is very poor at achieving sterility as compared to steam. Steam at 134° C. can achieve in 3 minutes the same sterility that hot air at 160° C. can take two hours to achieve. Prior art autoclaves and autoclaving methods achieve air removal by various means including downward displacement (or gravity type), steam pulsing, vacuum pumps, superatmospheric cycles, and subatmospheric cycles. However, prior art systems and methods have not sufficiently accounted for air pockets that tend to form within the mass of objects being autoclaved. An air pocket located within a mass may prevent the interior of the mass from reaching sterilizing temperatures as quickly as the remainder and/or exterior of the mass, and thus some prior art systems and methods require more time and energy to complete sterilization than is otherwise desired.
Accordingly, it is an object of the present disclosure to overcome one or more of the above-described drawbacks and/or disadvantages of the prior art.
In accordance with a first aspect, the present disclosure is directed to a containerized medical waste treatment system (hereinafter “containerized treatment system”). The containerized treatment system allows, if desired, for a mobile unit which can perform a complete waste handling and sterilization process. The containerized treatment system can function as a less expensive alternative to either transporting medical waste to a remote sterilization center, or to an on-site medical waste treatment system. In a currently preferred embodiment of the present disclosure, the containerized treatment system can be placed at a loading dock of a facility, accept carts of waste from the facility either from the dock or from ground level, sterilize the waste in an autoclave adapted to receive the carts of waste, mechanically/hydraulically tip a cart of sterilized waste from the autoclave to transfer the sterilized waste into a shredder, shred the sterilized waste into relatively small unrecognizable pieces, and transfer the sterilized, shredded waste by a conveyor, such as a two-belt conveyor system, to a nearby refuse container.
In accordance with another aspect, the present disclosure is directed to a containerized waste treatment system for sterilizing and processing waste. The system comprises an elongate enclosure defining a front end, a rear end, and at least two side walls laterally spaced on substantially opposite sides of the enclosure relative to each other and extending between the front and rear ends of the enclosure. A platform extends in an elongate direction between the front and rear ends, and extends laterally between the two side walls of the enclosure. An access opening, such as a side door, extends through a side wall of the enclosure, or if desired, each side wall includes an access opening, to allow entry of an operator and cart into the enclosure and egress out of the enclosure therethrough. An autoclave is mounted within the enclosure on the platform adjacent to either the front end or the rear end of the enclosure. A shredder is mounted within the enclosure on the platform adjacent to either the front end or the rear end of the enclosure. The shredder and the autoclave are spaced relative to each other and define a cart path therebetween within the enclosure. The cart path is in communication with the access opening to allow the operator to move a cart containing a load of waste through the access opening, onto the cart path, from the cart path into the autoclave, sterilize the load of waste in the autoclave, retrieve the load of waste from the autoclave, move the cart with the sterilized load of waste along the cart path to the shredder, move the load of sterilized waste from the cart into the shredder, shred the sterilized waste in the shredder, and dispose of the sterilized, shredded waste.
In some currently preferred embodiments, the containerized treatment system comprises (i) a standard semi-truck trailer or a standard semi-truck shipping container; (ii) at least one side door located at about the midpoint of the enclosure for introducing a cart of waste into the enclosure; (iii) an autoclave mounted within the enclosure forwardly of the at least one side door and approximately over support structure(s) for receiving the waste from the cart and sterilizing the waste by the application of steam; (iv) a shredder for shredding sterilized waste located rearwardly of the at least one side door and approximately over the rear wheels of the enclosure or of a platform beneath the enclosure; (v) a cart track extending from the floor of the enclosure to the autoclave for loading carts of waste into the autoclave; (vi) a tipper located forwardly of the shredder for transferring the contents of the cart into the shredder and, in turn, shredding the waste; (vii) a moveable roof panel located on the roof of the enclosure above the tipper or shredder to allow for increased vertical space to accommodate the cart when lifted by the tipper over the shredder to transfer the waste into the shredder; (viii) a conveyor positioned to accept shredded, sterilized waste from the outlet of the shredder and transport the shredded, sterilized waste to a receptacle, including a lower translatable belt, that is laterally translatable from one side of the enclosure to the other, and an upper stationary belt located at the outlet of the shredder and extending from approximately one side of the enclosure to the other side; (ix) at least one hinged member located on at least one side of the enclosure and extending from or between the rear end of the enclosure to a respective side door, wherein the at least one hinged member can pivot from an open position that is substantially perpendicular to the respective side of the enclosure to a closed position that is substantially parallel to, or otherwise located against or immediately adjacent to the respective side of the enclosure, wherein at least one end of the member is capable of pivoting downwardly in order to contact the ground; and (xi) utility connections mounted on the sides or bottom of the enclosure to provide utilities to the components of the system, including a plurality of electrical connections, a steam connection, a water connection, and a drain connection.
In some embodiments, the containerized treatment system includes a plurality of utility connections located at the facility that correspond to a plurality of the utility connections mounted on the enclosure to provide utilities to the components of the system, such as a plurality of electrical connections, a steam connection, a water connection, and a drain connection. The utility connections may or may not include quick-disconnect type connections. In some embodiments, the containerized treatment system further includes an umbilical cord for connecting utility connections on the enclosure to utility connections at the facility. In another embodiment, the containerized treatment system includes an umbilical connection extending from the enclosure, that houses utility connections, and is capable of providing utilities to the system. In such an embodiment, the system further includes a substantially similar umbilical connection located at the facility and capable of connecting to the umbilical connection extending from the enclosure to thereby provide utilities to the system.
In some embodiments of the present disclosure, the containerized treatment system includes a document destruction and collection device. In a currently preferred embodiment of the present disclosure, the containerized waste treatment system performs paper document destruction with the onboard waste shredder. The documents are loaded into the shredder in a manner that is the same as, or similar to, the manner of loading other waste into the shredder, in that the documents can be loaded through carts and a tipper associated with the shredder. In addition, the containerized treatment system may include means to collect and transport the destroyed paper documents from the outlet of the shredder. The collection means may take the form of a vacuum mounted to apply suction to the top of a conveyor belt which is sized and positioned to receive the outlet of the shredder. In such an embodiment, the vacuum removes the shredded documents from the conveyor belt and transports the material through a conduit to a waste receptacle. In some embodiments of the present disclosure, the shredded documents are transported to a separate waste receptacle, such as paper recycling or other recycling bin, to facilitate recycling of the shredded documents.
In accordance with another aspect, the present disclosure is directed to a sterilization method. The sterilization method comprises the following steps:
(i) providing a containerized enclosure including a side door, an autoclave mounted to one side of the side door within the interior of the enclosure, and a shredder mounted to an opposite side of the side door within the interior of the enclosure, and a cart path extending between the side door, autoclave and shredder;
(ii) transporting the containerized enclosure with a vehicle from a first location to a second location;
(iii) with the enclosure located in the second location, introducing a cart containing a load of waste through the side door into the enclosure;
(iv) placing the cart within the autoclave and sterilizing the load of waste within the autoclave;
(v) moving the cart with the sterilized load of waste along the cart path from the autoclave to the shredder;
(vi) moving the sterilized waste from the cart into the shredder and shredding the sterilized waste; and
(vii) discharging the shredded sterilized waste from the enclosure into a nearby refuse container.
In accordance with another aspect, the present disclosure is directed to a sterilization method including the following steps:
(i) sealing an autoclave to achieve a substantially air-tight space within the autoclave and surrounding a load of waste;
(ii) performing a first evacuation, wherein the first evacuation removes air from the autoclave and brings about a pre-determined first pressure below atmospheric to the load;
(iii) introducing condensable vapor having transferable latent heat at a pre-determined first temperature to the substantially air-tight space, wherein the introduction brings about a pre-determined first pressure above atmospheric to the load;
(iv) allowing the condensable vapor to transfer heat to the load for a first time period under the first pressure above atmospheric;
(v) performing a second evacuation, wherein the second evacuation removes a pre-determined amount of the condensable vapor and air from the autoclave to bring about a second pressure below atmospheric to the load;
(vi) introducing condensable vapor having transferable latent heat at a pre-determined second temperature to the substantially air-tight space, wherein the introduction brings about a pre-determined second pressure above atmospheric to the load;
(vii) allowing the condensable vapor to transfer heat to the load for a second time period under the second pressure above atmospheric, wherein the second time period is substantially the same as or similar to the first time period;
(viii) performing a third evacuation, wherein the third evacuation removes condensable vapor and air from the autoclave to bring about a third pressure below atmospheric to the load;
(ix) introducing condensable vapor having transferable latent heat at a pre-determined third temperature to the substantially air-tight space, wherein the introduction brings about a pre-determined third pressure above atmospheric to the load;
(x) allowing the condensable vapor to transfer heat to the load for a third time period under the third pressure above atmospheric, wherein the third time period is substantially longer as compared to the first and second time periods, to substantially sterilize the load; and
(xi) performing a fourth evacuation, wherein the fourth evacuation removes condensable vapor and air from the autoclave to bring about a fourth pressure below the third pressure.
In some such embodiments, the second pressure below atmospheric is substantially similar to the first pressure below atmospheric; the pre-determined second pressure above atmospheric is substantially similar to the pre-determined first pressure above atmospheric; the third pressure below atmospheric is substantially the same as or similar to the first and second pressures below atmospheric; and the pre-determined third pressure above atmospheric is substantially similar to the pre-determined first and second pressures above atmospheric.
In a currently preferred embodiment, the load is medical waste, the first and second heating time periods are each within the range of about 2 minutes to about 10 minutes, and the heat during at least the third time period is sufficiently high to sterilize the medical waste. In one embodiment, the first, second, or third temperatures are each within the range of about 275 degrees Fahrenheit to about 300 degrees Fahrenheit. In another embodiment, the first, second, and third pressures below atmospheric are each within the range of about 6 inches of water vacuum to about 20 inches of water vacuum. The sterilization method may further include the step of allowing the sterilized medical waste to cool to a handling temperature. In alternative embodiments, steps (v), (vi), and (vii) define a cycle which may be repeated at least one time before step (viii). If an air pocket forms within the mass of the load during such first or second cycles, the method may loosen the mass of the load, or otherwise act to remove the air pocket from the mass, and further remove from the autoclave the air from the air pocket.
One advantage of the containerized medical waste treatment system and method is that they allow for a unit that can be transported, and if desired, may itself be mobile, and which can perform a complete waste handling and sterilization process at, for example, a remote facility. Another advantage of the containerized medical waste treatment system and method is that they can function as a less expensive alternative to transporting medical waste to a remote sterilization center or to an on-site medical waste treatment system. Yet another advantage of some currently preferred embodiments of the containerized medical waste treatment system and method is that they provide a document destruction and recycling process along with medical waste sterilization and processing. This feature can be significantly advantageous with respect to properly shredding and disposing of Health Insurance Portability and Accountability Act (“HIPAA”) documents, for example. Yet another advantage is that providing one system, that performs both document shredding and medical waste disposal functions, can give rise to enhanced efficiencies and significant cost savings in comparison to the prior art. Another advantage of the currently preferred embodiment of the sterilization method is that the method allows for shorter overall sterilization cycle times as compared to prior art autoclave systems.
These and other advantages of the present invention, and/or of the currently preferred embodiments thereof, will become more readily apparent in view of the following detailed description of the currently preferred embodiments and the accompanying drawings.
a is a front side view of a currently preferred embodiment of a medical waste sterilization cart of the present disclosure;
b is a bottom view of the medical waste sterilization cart of
c is a right side view of the medical waste sterilization cart of
In
The main structure containing the sterilization and processing equipment is a container or enclosure 10. The enclosure 10 houses the sterilization and processing equipment and provides a base that permits them to be operated and transported from one location to another. In the illustrated embodiment, the enclosure 10 is an elongate, rectangular structure. Also in the illustrated embodiment, the enclosure 10 is capable of interacting with devices for transporting or moving the container or enclosure 10 from one location to another, and such devices may include, for example, hitching means (e.g., a hitch on a vehicle), support structures, and/or wheels. In the currently preferred embodiment, the enclosure 10 includes a floor, walls, a roof, a hitch mechanism (not shown), support structures, and an axle(s) and/or wheels attached thereto. As shown in
In one exemplary embodiment, the enclosure 10 is shaped and dimensioned to be placed on a carrier platform that is mobile, such as a carrier platform with wheels, as well as on a permanent structural stand and/or directly on ground level. However, those skilled in the art will recognize that many variations of the enclosure 10 are possible, including variations in size, shape, configuration, components and/or compatibility with transportation means, without departing from the spirit and scope of the present invention, including for example structures capable of being transported by wheels, flatbed trailers, trailer trucks, boats, and by railway. Accordingly, the term “containerized” is used herein to mean any enclosure, container or device that contains at least a plurality of the components of the system (e.g., the autoclave and shredder), and that may or may not itself be mobile. For example, in one embodiment, the enclosure is defined by a standard shipping container that can be transported on a flat bed trailer, railcar or boat. In other embodiments, the container itself is mobile, and may be defined by, for example, a trailer that includes wheels and a hitch for hitching the trailer to a semi or tractor-trailer.
As shown in
In the illustrative embodiment shown in
The side walls, front and back walls, base 97 and lid 94 of the carts 16 are made from a material that is durable enough to handle medical waste, such as sharps, and able to withstand the high temperature, pressure and moisture parameters associated with an autoclave sterilization process, such as the sterilization process described in further detail below. The thickness of the material gives the carts 16 sufficient rigidity and sturdiness to securely hold a mass of waste therein. On the other hand, a material that is thinner will transfer heat more quickly through the material and absorb less total heat, so as to decrease the autoclave time and total energy and interfere with sterilization of the waste by an autoclave as little as possible. In addition, the thinner the material, the less the cart weighs, increasing the mobility of the cart and ease of use by a user. In the illustrative embodiment, a 5000 series aluminum alloy, such as Aluminum 5052-H32, with a material thickness of about ⅛ inch thick used. This provides adequate durability and acceptable material thickness and weight with associated heat transfer and specific heat characteristics. Other materials may be used that provide such adequate characteristics. In preferred embodiments, the material has a specific heat capacity of about ⅕ BTU/pounds-degree Fahrenheit and a thermal conductivity of about 960 BTU/pounds-degree Fahrenheit.
The carts 16 also include steam penetration apertures 92 in the side walls of the carts 16. The steam penetration apertures 92 allow steam to more easily enter the interior of the carts 16 during the sterilization process in, for example, the autoclave 18, as compared to a cart that does not include such apertures. In the illustrative embodiment, the steam penetration apertures 92 are located around the periphery of the bottom portion of the side, back and front walls of the carts 16 adjacent the base portion 97. The steam penetration apertures 92 are arranged linearly and are equally spaced from one another along the side, front and back walls of the carts 16. Three steam penetration apertures 92 are formed in the lower portion of the front and back walls, and four steam penetration apertures 92 are formed in the side walls of the carts 16. The steam penetration apertures 92 allow steam to enter the interior of the carts 16 and contact the contents of the carts 16, such as a liner that is positioned in the carts 16 and that contains waste therein.
The carts 16 also may contain a liner (not shown) that is durable enough to handle medical waste, such as sharps, and is able to withstand the high temperature, pressure and moisture parameters associated with autoclave sterilization (e.g., not deteriorate or melt), such as the sterilization process described in further detail below. The also liner prevents liquids and other materials from escaping from the carts 16. The liner also resists sticking, melting, adhering or otherwise becoming coupled to the carts 16 during sterilization in an autoclave. In a preferred embodiment, the liner is made from a polypropylene blend including a slip and an anti-block component, and has a melting point of about 159 degrees Centigrade.
In addition, both the cart material and the liner should be selected so as to prevent the liner from becoming stuck against the cart 16 material surface due to thermal expansion and contraction during the autoclave temperature/pressure cycling. More specifically, it has been observed that with some combinations of liners and cart materials, the liner material becomes entrained in the microscopic surface structures of the cart material, e.g., pores, preventing removal of the liner from the cart surface, e.g., for disposal, or otherwise making removal more difficult. This entrainment is not a function of the liner material melting, deforming or plastically flowing into the surface structures at elevated temperature, or it molecularly bonding to the cart material. Rather, the entrainment seems to be primarily a function of the surface features (hereinafter referred to generally as “pores”) expanding due to heating during autoclaving, the liner material moving into the expanded pore space, and then becoming physically entrained or pinched in the pores when they contract during cooling. The above-discussed aluminum alloy cart materials and polypropylene liner materials do not exhibit excessive sticking in the autoclave processes discussed herein.
When a particular liner will become entrained with a particular cart material depends on a number of factors. One would be the amount of thermal expansion/contraction of the material pores. This, in turn, is dependent upon both the expansion properties of the material, i.e., and coefficient of thermal expansion, and the overall temperature differential obtained during autoclaving. Relatedly, the number of thermal cycles during the autoclaving process may be a factor, as additional expansion/contraction cycles may allow more liner material to become entrained.
Other factors relating to cart material could include the number of pores, the diameter and shape of the pores, the depth of the pores, and the overall surface features, e.g., surface roughness, of the material. For example, the larger the pore, the greater the actual physical expansion during heating. As another example, greater surface roughness provides more surface area with which the liner might become entrained or coupled.
Liner materials characteristics are also relevant. While bulk physical properties of the liner, such as flexibility and bending of the liner at temperature may play a role in potential entrainment, the surface characteristics of the liner are potentially important. A rougher or more uneven surface provides more material area for entrainment. Further, diametrically smaller but higher surface features are more likely to have the size and shape to extend into the expanded pores at temperature. For example, a thin but long or tall surface feature on the liner has more potential to be diametrically small enough to fit into an expanded pore and to extend deeper into that pore, increasing the total liner material area retained and subsequent retention force thereon.
Though it is thermal expansion properties of the cart material that can cause liner entrainment, it should be understood that, within a particular class of materials, thermal expansion characteristics of materials do not greatly vary. For example, while steel and aluminum have significantly different thermal expansion characteristics from a metallurgical standpoint, the thermal expansion characteristics of most commercially-used aluminum and aluminum alloys, such as discussed herein, do not vary nearly as significantly. Further, over the temperature range of the autoclaving process, the total thermal expansion of the cart material is a fraction of a percent. Therefore, the surface characteristics of the cart material and/or the liner material play a much larger role in entrainment than the thermal expansion characteristics of one type of cart material over another. Generally, it is desirable to select cart and/or liner materials that present the lower potential entrainable surface area.
To further enhance the ingress and egress of the carts 16 and personnel with respect to the enclosure 10, the preferred embodiment includes a hinged member or platform 34 located on a side of the enclosure 10 and extending from the rear end of the enclosure 10 to at least a respective side door 14, as best shown by
In the illustrative embodiment, the hinge member 34 also includes support structures 35 that extend between the hinge member 34 and the ground to support the hinge member 34 in the “open” position, as best shown in
In a preferred embodiment, the waste treatment system 100 further includes an autoclave 18 mounted within the enclosure 10, forwardly of the side door 14, for receiving the carts 16 and the waste therein. In one preferred embodiment, as shown in
Other equipment associated with the autoclaving sterilization process may be positioned near and/or in contact with the autoclave 18. In the illustrative embodiment, the autoclave 18 makes use of a vacuum pump assembly 50 to apply a vacuum to the carts 16 and waste therein during an autoclaving sterilization process, as described in further detail below. The vacuum assembly 50 is positioned above the autoclave 18 and is in fluid communication therewith. In an alternative embodiment, utilities or equipment associated with the autoclaving process may be located adjacent the autoclave 18 in a separate compartment located forwardly of the autoclave 18. The compartment can be enclosed to insulate the area, for example, because of noise, accessibility, or safety. In such an embodiment, the enclosed area may house a steam generator for the production and supply of steam to the system's equipment, including the autoclave 18, and a water softener and a brine tank for supporting the steam generator. As another example, the compartment may include an electric generator for the production and supply of electrical current to the system's components which utilize electricity, such as a shredder 20.
As shown in
A shown in
The containerized treatment system further includes a shredder 20, located rearwardly of the autoclave 18 and the side door 14, for processing waste into smaller particles as compared to before processing. As shown in
As shown in
A tipper 24 is provided for receiving a cart 16 of waste from the autoclave 18, and transferring the contents of the cart 16 into the shredder 20 for processing. The tipper 24 includes a base or frame 68 for supporting the tipper's components and a cart 16 of waste thereon. The tipper frame 68 and other components associated with the tipper 24 are preferably positioned relatively close to shredder 20. The tipper frame 68 may be coupled to the floor (or internal floor 66), walls and/or ceiling of the enclosure 10. A vertically extending hydraulic cylinder 70 is coupled to, and thereby supported by, the tipper frame 68. A cart engaging member is coupled to the hydraulic cylinder 70 for vertical movement therewith. In the illustrative embodiment, the cart engaging member is an elongate, flat member which is rotatably coupled to the tipper 24 and extends from the tipper 24 toward the autoclave 18. The cart engaging member is shaped and designed to fit into the tipper slot 86 provided on the underside of the base 97 of each cart 16, as shown best by
In the illustrative embodiment, the tipper slot 86 on the underside of the base 97 of cart 16 resembles a ‘U’ shape, thereby providing a substantially enclosed area for the cart engaging member to enter and be supported thereby. The tipper slot 86 may be shaped or designed differently, but should preferably include at least top, bottom and side members to adequately surround the elongate cart engaging member. At a first state (not shown), the cart engaging member is substantially aligned with the tipper slot 86 so that the cart 16 can be manually translated on the floor of the enclosure 10 (or internal floor 66) toward the tipper 24 and the cart engaging member positioned substantially into the tipper slot 86.
At the first state, a hydraulic pump 72 powers the vertical hydraulic cylinder 70 vertically towards the moveable roof panel 26, thereby vertically translating the cart tipper member and the cart 16 thereon. The vertical movement may be initiated by an automatic sensor that recognizes that a cart 16 has been positioned onto the tipper member, or by manually directing (e.g., by pushing a lever) the hydraulic pump 72 to begin powering the vertical hydraulic cylinder 70. At a second state (not shown), the cart 16 is positioned on the cart engaging member and sufficiently elevated, as compared to the shredder 20, for transferring its contents into the shredder 20. In an exemplary embodiment, a sensor may detect sufficient elevation of the cart 16 and stop further vertical movement. In another embodiment, the second state represents the maximum vertical height that the vertical hydraulic cylinder 70 is capable of achieving. At the second state, a second hydraulic cylinder is powered by the hydraulic pump 72 to rotate the cart engaging member, and the cart 16 thereon, about a pivot point 74 towards the roof of the enclosure 10. The second hydraulic cylinder should continue to rotate the cart 16 past horizontal to a third state (as shown in
The cart 16 is prevented from translating or falling into the shredder 20 at the third state due to the interaction of the bottom portion of the tipper slot 86 (as viewed when the cart 16 is on the ground) and the bottom surface of the cart engaging member. Friction between the tipper panel 76 and the cart 16 may further prevent the cart 16 from translating toward the shredder 20. The tipper panel 76 is a substantially flat, elongate panel coupled to the vertical hydraulic cylinder 70 and positioned between the shredder 20 and a cart 16 engaged with the tipper 24. From the perspective of the first state, the tipper panel 76 should be substantially taller and wider than the cart 16. In the third position, as shown in
In one embodiment, the first, second and third states, as referenced above, are automatically controlled through sensors which detect the movements and positions of the tipper's components and the cart 16 thereon. The tipper 24 includes a tipper control box 48 for controlling the vertical movement and rotating or pivoting movement of the tipper 24 and a cart 16 thereon. As shown in
The waste treatment system further includes a moveable roof panel 26 for clearance between a cart 16 on the tipper 24 and the roof of the enclosure 10. The moveable roof panel 26 is hinged or otherwise configured to open and create more vertical space above the tipper 24 and/or shredder 20. The moveable roof panel 26 is designed and configured to maintain the integrity of the enclosure 10 in the “open” or “closed” positions of the roof panel 26. To maintain a substantially enclosed area in the open position, a flexible material 78 is coupled between the areas of the moveable roof panel 26 and enclosure 10 that separate from one another as the movable roof panel 26 travels into the “open” position from the “closed” position. The flexible material 78 is folded or otherwise gathered in the closed position and pulled substantially taut in the “open” position. The flexible material 78 can be pre-shaped and dimensioned to the required coverage area in the fully “open” position. In one embodiment, the flexible material 78 is a canvas. The moveable roof panel 26 may be motorized and controlled by a control box, such as the tipper control box 48, or may be mechanically engaged or otherwise linked with the tipper 24 and thereby operate as an automatic step in the tipper's operation. In the illustrative embodiment, as shown in
As shown in
One of the belt conveyors of the two-belt conveyor system is an upper main belt 30. The upper main belt 30 is permanently positioned under the outlet of shredder 20 to receive shredded, sterilized waste therefrom. The upper main belt 30 is sized, lengthwise, smaller than the width of the enclosure 10. The upper main belt 30 preferably is automatically activated whenever the shredder 20 is in the process of shredding waste, or conversely, may be individually controlled. In the preferred embodiment, the upper main belt 30 is motorized and able to translate waste thereon laterally across the width of the enclosure 10 (from one side wall to the other side wall). A control box/panel may be incorporated with the two-part conveyor system 28 to control the direction of the upper main belt 30. For example, if the containerized treatment system 100 is positioned along a facility's loading dock, the upper main belt 30 can translate the waste in a direction away from the dock and toward, for example, an adjacent or nearby receptacle 60.
To further enhance the processing and output capability of the containerized treatment system, a preferred embodiment includes a lower translatable belt 32, located beneath the upper main belt 30, as the second part of the two-part conveyor belt system 28. The lower translatable belt 32 is capable of being translated across the width of the unit, and thereby extended from a side of the enclosure 10 a pre-defined distance. In such an embodiment, the lower translatable belt 32 is controlled and powered to translate waste in the same direction as the upper main belt 30. In use, the upper main belt 30 translates waste from the output of the shredder to the edge of the upper main belt 30. Once the waste reaches the edge of upper main belt 30, waste is gravity fed onto the lower translatable belt 32 and further translated away from the enclosure 10 and, preferably, into a receptacle 60 positioned near the enclosure 10 and under the lower translatable belt 32, such as a compactor or Dumpster™. As may be recognized by those of ordinary skill in the pertinent art based on the teachings herein, the particular type of conveyor system described herein is only exemplary, and any of numerous types of conveyor systems that are currently known or that later become known equally may be employed, such as systems with more than two belts, systems with one belt, systems which include belts that can pivot with respect to one another, or other non-belt systems capable of transporting shredded, sterilized waste from the output of the shredder into a nearby receptacle.
Turning to
In
In
In the illustrative embodiment, as shown in
In a currently preferred embodiment of the present disclosure, the containerized treatment system includes a document destruction and collection device. The containerized waste treatment system can be capable of paper document destruction with, for example, the onboard waste shredder 20. The documents are loaded into the shredder 20 similar to sterilized waste, in that documents can be loaded through carts 16 and the tipper 24 associated with the shredder 20. Further, the containerized treatment system may include a collection and transport means to collect and transport the destroyed paper documents from the outlet of the shredder 20. The collection and transport means includes a vacuum system 58 mounted adjacent to the two-belt conveyor system 28 in such a way as to apply a downwardly directed suction to the top of the upper conveyor belt 30, which is sized and positioned to receive shredded waste discharged at the outlet of the shredder 20. In this embodiment, the vacuum system 58 removes shredded documents from the upper conveyor belt 30 and transports the material to a waste receptacle through a conduit 82, such as pipe or tube.
The disclosed systems further includes a computer or computerized controller 84 to take, receive, and/or store data relating to the status of the system, such as but not limited to, the number of carts processed, autoclaving times, the amount of waste processed, the amount of time at a particular position, utility consumption, and conditions inside the enclosure 10. The system may further include the ability to transmit the collected data to, or allow the data to be retrieved from, a remote location, such as by satellite, or other wireless or network devices that are currently known, or that later become known.
The sterilization method of the system 100 may be customized to minimize autoclaving time and, therefore, increase efficiency. One such sterilization method includes the following steps:
(i) Providing an autoclave;
(ii) Placing a load to be sterilized in the autoclave;
(iv) Sealing the autoclave to achieve a substantially air-tight space within the autoclave and surrounding the load;
(v) Performing a first evacuation, wherein the first evacuation removes a pre-determined amount of air from the autoclave and brings about a pre-determined first pressure below atmospheric to the load;
(vi) Introducing a pre-determined amount of condensable vapor having transferable latent heat at a pre-determined first temperature to the substantially air-tight space; This introduction brings about a pre-determined first pressure above atmospheric to the load;
(vii) Allowing the condensable vapor to transfer heat to the load for a first time period under the first pressure above atmospheric;
(viii) Performing a second evacuation, wherein the second evacuation removes a pre-determined amount of the condensable vapor and air from the autoclave to bring about a second pressure below atmospheric to the load; The second pressure below atmospheric is substantially similar to the first pressure below atmospheric;
(ix) Introducing a pre-determined amount of condensable vapor having transferable latent heat at a pre-determined second temperature to the substantially air-tight space; This introduction brings about a pre-determined second pressure above atmospheric to the load; The pre-determined second pressure above atmospheric is substantially similar to the pre-determined first pressure above atmospheric;
(x) Allowing the condensable vapor to transfer heat to the load for a second time period under the second pressure above atmospheric; The second time period is substantially the same as or similar to the first time period;
(xi) Performing a third evacuation, wherein the third evacuation removes a pre-determined amount of the condensable vapor and air from the autoclave to bring about a third pressure below atmospheric to the load; The third pressure below atmospheric is substantially the same as or similar to the first and second pressure below atmospheric;
(xii) Introducing a pre-determined amount of condensable vapor having transferable latent heat at a pre-determined third temperature to the substantially air-tight space; This introduction brings about a pre-determined third pressure above atmospheric to the load; The pre-determined third pressure above atmospheric is substantially similar to the pre-determined first and second pressure above atmospheric;
(xiii) Allowing the condensable vapor to transfer heat to the load for a third time period under the third pressure above atmospheric; The third time period is substantially longer as compared to the first and second time periods to substantially sterilize the load; and
(xiv) Performing a fourth evacuation, wherein the fourth evacuation removes a pre-determined amount of the condensable vapor and air from the autoclave to bring about a fourth pressure below the third pressure.
In the exemplary embodiment, the fourth evacuation may lower the pressure in the autoclave so that the autoclave can be opened without large amounts of steam and pressure escaping. Also, such a feature may allow the autoclave door or cover to be easily opened or the autoclave's substantially airtight portion unsealed. In one embodiment, the sterilization method includes the step of allowing the load to cool to a handling temperature before the autoclave is opened, the airtight portion unsealed, or the load removed from the autoclave.
Preferably, the time periods, temperatures and pressures of each step are pre-determined and specifically designed for a particular load or application. By varying the aforementioned variables, the disclosed autoclaving method can be tailored to achieve sterilization in a shorter time period as compared to previously known methods by removing air from the load. In one preferred embodiment, the first and second time periods are in the range of about 2 minutes to about 10 minutes, the first, second, and third temperatures are in the range of about 275 degrees Fahrenheit to about 300 degrees Fahrenheit, and the first, second, and third pressures below atmospheric range from about 6 inches of water vacuum to about 20 inches of water vacuum. In one embodiment, the third time period is in the range of about 20 minutes to about 45 minutes. In another embodiment, the third time period is at least 1½ times the first and second time periods. In some embodiments, all of the first, second, and third temperatures are sufficiently high to sterilize medical waste. In some embodiments, the step of introducing a pre-determined amount of condensable vapor having transferable latent heat is done rapidly, for example, by injecting the steam into the autoclave to relatively quickly bring about the pre-determined pressure above atmospheric to the load.
In one embodiment, steps (viii), (ix), and (x) define a cycle. In this embodiment, the cycle may be repeated at least one time before step (xi) is formed. The amount of cycles performed on a load can be a variable that can be changed to suit a particular load or application due, for example, to the weight of the load. In one such example, an extremely porous load or a load with large amounts of trapped air within the load may require more cycles than a non-porous load. Other examples of loads which may require the cycle to be repeated at least one time, are loads which include air pockets in the space within a cylindrical member, such as a syringe, or form that air pockets in difficult-to-access areas of the load. Another example of loads which may require the cycle to be repeated at least one time are loads with errors in packaging, such as overloading of the sterilizer chamber of the autoclave.
As previously discussed, the exemplary sterilization methods of the present disclosure may reduce the sterilization procedure time as compared to previous methods because of the removal of air pockets. As such, in the exemplary embodiments, the load may form at least one air pocket within the mass of the load during the method, which is then removed from the load and autoclave during the method. Without being limited to a particular theory, the disclosed methods may advantageously remove air pockets from the load being sterilized because the vacuum acts to give the load buoyancy as compared to a load that is not subjected to a vacuum. Therefore, the vacuum may act to prevent the load from bearing down upon itself and thereby forming air pockets. The buoyancy feature and the introduction of steam may allow the steam to penetrate the load advantageously and remove the air pockets as compared to the load without a vacuum. The method may be characterized as not allowing the load to bear down upon itself and thereby form air pockets which cannot be penetrated by steam and the load thereby insulates itself against the high temperatures of the steam. The method may be further characterized as a loosening of the load to allow the air pockets to be removed from the load, which allows for steam to penetrate the entire mass of the load and prevent the load from insulating itself against the high temperatures of the steam.
It may be readily understood by those having skill in the pertinent art from the present disclosure that any of numerous changes and modifications may be made to the above described and other embodiments of the present disclosure without departing from the scope of the invention as defined in the appended claims. For example, the containerized medical treatment system may be made from any of numerous different materials, in any of numerous shapes, taking any of numerous different dimensions. In addition, the utility connections may be releasably attachable to the containerized unit in any of numerous different ways that are currently known, or that later become known. The term “enclosure” is used herein to broadly define any transportable structure capable of housing in whole or in part sterilization or processing equipment, and may or may not include walls, a roof, support stilts, hitch means, axles, wheels, etc. The phrase “autoclave” is used herein to mean a pressurized device designed to heat aqueous solutions above their boiling point at normal atmospheric pressure to achieve sterilization. The term “shredder” is used herein to mean any means capable of breaking apart or processing a load material of one size into relatively smaller pieces, and may or may not include a rotating shaft, motor, cutting element, gears, hopper, bearings, and control means. The term “tipper” is used herein to mean any means capable of accepting a cart or like device for holding a load of waste and transferring the load into a shredder, including without limitation a hydraulic lifting and tipping mechanism. Accordingly, this detailed description of the currently preferred embodiments of the present disclosure is to be taken in an illustrative, as opposed to a limiting sense.
This application claims priority to similarly titled U.S. Patent Application No. 61/117,573, filed Nov. 24, 2008, the contents of which is expressly incorporated by reference in its entirety as part of the present disclosure.
| Number | Date | Country | |
|---|---|---|---|
| 61117573 | Nov 2008 | US |
