Patent Application
20090250535
The present invention relates to the treatment of municipal solid waste and the like.
The present invention relates to systems and methods for treating process material and, more particularly, to systems and methods for treating municipal solid waste material, medical waste material, reclaimed paper and the like.
As a result of increasing scarcity of landfills and more stringent environmental regulations, efforts have been made to reduce the volume of process material, such as municipal solid waste (“MSW”) and paper material, such as newsprint and other reclaimed and recycled paper products as a step in the process of disposing of the material, either by depositing it in landfills, incinerating it or recycling it.
Systems and methods have been developed to break down such material for disposal, or in the case of paper products, use as insulation.
An example of such a process and device is U.S. Pat. No. 5,190,226, which discloses an apparatus and method for separation, recovery and recycling of MSW. The apparatus includes a rotating drum which is fed at an upstream end by a reciprocating ram, a steam source which is connected to introduce high temperature steam into the drum, and a spiral rib or flight mounted within the drum to transport material deposited in an upstream end of the drum along the length of the drum.
Another example is described in U.S. Pat. No. 5,119,994 that describes a steam treatment vessel held stationary, preferably at an angle to the horizontal.
One method of attempting to achieve more efficient treatment is described in U.S. Pat. No. 6,397,492 and involves the continual supply of steam during loading, while simultaneously rotating the vessel, so as to break down the waste during loading to a material of roughly uniform density, so that the same mass of waste is processed in each batch. However, this process requires a separate steam treatment during loading which results in greater overall time requirements for each waste batch.
One of the disadvantages of the arrangements of the prior art is that the environments surrounding the vessel may be harmful to those loading, operating or discharging the vessel.
Accordingly, it is also advantageous to be able to provide safe and functional working environments around vessels of this type, for persons involved in loading, operating or discharging the vessel or otherwise.
In this same regard, the environment surrounding the vessel upon loading differs from that surrounding the vessel upon discharge. As these environments differ, it is also desirable to be able to provide a waste treatment vessel that may be loaded, operated or discharged while maintaining some degree of separation or isolation of the loading environment from the discharge environment.
The present invention accordingly represents an improvement over prior art apparatus and methods, such as those described in U.S. Pat. Nos. 5,540,391; 5,116,363; 5,253,764; 5,190,226; 5,361,994; 5,427,650; 5,407,809; and 6,397,492, all of which are hereby incorporated herein by reference. PCT application PCT/US06/16773 and co-pending patent application Ser. No. 11/716,101 are also incorporated herein by reference. PCT Published application WO2006056768 A9 is also hereby incorporated herein by reference.
The present invention includes an apparatus for processing solid waste products, the apparatus comprising: a rotatably mounted cylindrical vessel having a first end and a second end, a hatch at both the first end and the second end that may be opened to allow access to the interior of the vessel to a respective first and second environmental space outside the interior of the vessel, and sealably closed to allow pressurization of the vessel; a steam inlet for injecting steam into at least one of the ends; and means for at least partially separating the environments of the first and second environmental space.
The present invention may be adapted to be used in accordance with prior vessel systems such as those described in the incorporated references.
Examples of means for at least partially separating the first and second environments include a wall through which the vessel extends, an air curtain through which the vessel extends, a material curtain through which the vessel extends and a trough adapted to accept liquids from at least one of the environmental spaces.
The present invention includes an apparatus for processing solid waste products, the apparatus comprising: (a) a rotatably mounted cylindrical vessel having a first end and a second end, a hatch at both the first end and the second end that may be opened to allow access to the interior of the vessel to a respective first and second environmental space outside the interior of the vessel, and sealably closed to allow pressurization of the vessel; (b) a steam inlet for injecting steam into at least one of the ends; and (c) an environmental barrier for at least partially separating the environments of the first and second environmental space.
It is preferred that the environmental barrier for at least partially separating the environments of the first and second environmental space includes a wall through which the vessel extends. This may take the form of air curtain through which the vessel extends and/or a trough adapted to accept liquids from at least one of the environmental spaces. It may also include a curtain or a wall through which the vessel extends. Another preferred embodiment includes the use of bearings between the barrier material and a flexible material, such as a rubber gasket, and between the flexible material and the vessel so as to permit rotation and/or translocation of the vessel while maintaining the seal. As an alternative, the flexible material may be fixed to the barrier material and be made simply to bear against the vessel with enough force so as to permit rotation and/or translocation of the vessel while maintaining the seal.
It is also preferred that a pressure gradient is maintained between the environments of the first and second environmental space, such as by having the first environmental space (i.e., the upstream, waste input side of the vessel) be defined by a chamber and wherein the chamber is maintained under a positive air pressure.
In another preferred embodiment, the apparatus for processing solid waste products includes: (a) a rotatably mounted cylindrical vessel having a first end and a second end, a hatch at both the first end and the second end that may be opened to allow access to the interior of the vessel to a respective first and second environmental space outside the interior of the vessel, and sealably closed to allow pressurization of the vessel; (b) a steam inlet for injecting steam into at least one of the ends; and (c) an environmental barrier for at least partially separating the environments of the first and second environmental space; (d) an environmental chamber enclosing the first environmental space; and (e) an environmental chamber enclosing the second environmental space.
In a preferred embodiment, the environmental barrier for at least partially separating the environments of the first and second environmental space includes a wall through which the vessel extends and, optionally a device to maintain an air pressure differential between the first and second environmental spaces, such that air flow is urged from the first environmental space toward the second environmental space. Preferably, the first environmental space (i.e., the upstream, waste input side of the vessel) is defined by a chamber and wherein the chamber is maintained under a positive air pressure.
The environmental barrier may optionally include an air curtain provided to create a flow of air between the first and second environments.
It is preferred that the first and second environments be substantially completely isolated from the cross-flow of gases, liquids or other materials, such as particulates. In appropriate cases, an optional trough and/or half wall may be used to at least partially isolate the first and second environments from one another.
In a further preferred embodiment, the system includes a combustion chamber for combusting processed solid waste products from the vessel, and additionally comprising an air conduit adapted to conduct air from the first environmental space to the combustion chamber.
The vessel further includes at least one door or hatch, or similar means to access the interior of the vessel for loading and unloading the waste charge, which may be transported to the vessel by a conveyor or other traditional means.
The apparatus typically includes a means for rotating the vessel, such as those known and used in the art, such as trunnion rings and rollers, or chain-driven gear and sprocket systems or a “spud” ring. Any stable method of rotating the vessel at a controlled speed would be suitable. The rotation of the vessel however must also be able to accommodate its movement by the actuator(s) as described herein.
The vessel system may have many of the same characteristics of those known and used in the art, in terms of being designed to contain large quantities of matter (i.e., several tons) and to hold those contents under pressure. Examples are described in the incorporated references, and are known in the art.
The vessel may be supported in any fashion that allows movement while rotating, or it may be rotated while stationary. It is preferred that the vessel be supported by a hinged fulcrum point about which it may be moved.
In case where the vessel allows vertical and/or horizontal movement while rotating, the environmental barrier may be provided with structure, such as a flexible, heat resistant material to allow for the movement(s) of the vessel while it extends through the environmental barrier. Such materials may include a curtain of a heat resistant material, such as fiberglass, or a flexible collar about the vessel of a heat resistant material.
The present invention also generally includes a method for processing solid waste products, the apparatus comprising: (a) placing solid waste in a rotatably mounted cylindrical vessel having a first end and a second end, a hatch at both the first end and the second end that may be opened to allow access to the interior of the vessel to a respective first and second environmental space outside the interior of the vessel, and sealably closed to allow pressurization of the vessel; (b) placing a steam inlet for injecting steam into at least one of the ends while (c) maintaining an environmental barrier for at least partially separating the environments of the first and second environmental space.
It is preferred that a pressure gradient is maintained between the environments of the first and second environmental space. It is also preferred that the second environmental space is defined by a chamber and wherein the chamber is maintained under a positive air pressure with respect to the first environmental space.
In accordance with the foregoing summary, the following provides a detailed description of the preferred embodiment, which is presently considered to be the best mode thereof.
Conversely, the second end 3 of vessel 1 extends into chamber 7 such that hatch 5 allows the second end 3 of the vessel 1 to be opened to allow access to the interior of the vessel so that the processed waste may be removed from the second end 3 into chamber 7 such as by action of conveyor 9. This also may be done by using a ram that may push the treated charge from the vessel by extending through the vessel 1.
Also shown in
The vessel 1 may be rotated with respect to upper frame portion 16, such as by virtue of mechanical sleeve drives 17. The apparatus also includes at least one motor or other means for rotating the vessel.
The preferred vessel system is that described in co-pending patent application Ser. No. 11/716,101 and PCT Published application WO2006056768 A9 which describes a moveable vessel. The environmental barrier system may be adapted to permit rotational and vertical movement of the vessel, such as through the provision of an appropriately sized and dimensioned aperture 11 that allows the vessel 1 to move with respect to the balance of the wall 10 as it extends therethrough, and by preferably having a sealing material 12 of sufficient size and flexibility to accommodate that range of movement.
The invention relates to a process for recycling waste. This process is sterilizing high density materials such as glass, plastics, metals and recovering others from municipal solid waste (MSW) and converting paper, cardboard, food waste, etc. to a usable fiber and separating it from other recyclable materials.
The views of
After the vessel is loaded with the charge of waste products, the door through which the charge was loaded is shut, steam is introduced continually into the vessel, and the vessel becomes pressurized. Fresh steam may be continuously fed into the vessel from the loading end, and after a predetermined processing pressure is reached, steam may be allowed to escape the vessel into the discharge steam line.
In the preferred embodiment, a positive airflow is maintained between the first chamber 6 and the second chamber 7. This may be done by action of air movement devices such as fans 20 and 21 which force air into chamber 7 while fan 22 draws air out of chamber 6.
In a further preferred embodiment, the system includes a combustion chamber 23 for combusting processed solid waste products from the vessel, and additionally comprising an air conduit 24 adapted to conduct air from the first environmental space of first chamber 6 to the combustion chamber 23. The combustion chamber may be any chamber where combustion may occur and may include portions of systems designed to combust materials processed by the vessel 1. This assists in keeping the environment in chamber 7 relatively cleaner and free of odors.
The air removed from the first chamber 6 therefore is treated so as to remove odoriferous substances therefrom.
The chambers 6 and 7 typically will be closed from the outside environment to allow pressurization, although it will be understood that the present invention may still operate in instances where the separated environments may be opened temporarily to allow loading and unloading of the waste material from the vessel. Typically however, the downstream chamber will remain closed to allow its pressurization relative to the first chamber and the ambient atmosphere. This maintains the respective environments in a state where transmission of gases and the like from the upstream environment to the downstream environment are resisted. This helps maintain the cleanliness of the downstream environment to prevent contamination of the processed material and to make the working environment more suitable and pleasant for those working in the downstream environment. The preferred embodiment of the present invention also is capable of remediating odors to prevent the release to the environment in general.
It is apparent that while specific embodiments of the invention is disclosed, various modifications of the apparatus or parameters of the process may be made which will be within the spirit and scope of the invention. Therefore the spirit and scope of the present invention should be determined by reference to the claims below.
This application claims the priority benefit of U.S. Provisional Application No. 61/123,351, filed Apr. 7, 2008, which is hereby incorporated in its entirety herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61123351 | Apr 2008 | US |
