Abstract:
A track-based mobile system for use with processes generating air-borne pollutants, for preventing contamination of the atmosphere. An enclosure for containing air-borne pollutants and a filtering system for removing the pollutants from the air are movable as a unit along a track for use at a plurality of worksites. The unit is openable at opposing portions facing the track so as to be able to pass over workpieces at the plurality of work sites. The filtering system includes intake tubes, and dampers to enable the selection of air-flow patterns within the enclosure.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a system for use with metal cutting processes generating air-borne pollutants, so as to prevent pollution of the atmosphere.  
       BACKGROUND OF THE INVENTION  
       [0002]     In the processing of scrap metal, in particular ferrous metals for recycling in electric arc furnaces or the like, flammable gases in combination with oxygen gas in a cutting torch are used to cut large metal sections, too large for downstream recycling processing, into more useful sizes. Such cutting means are also used for separating recyclable ferrous metals from other materials, which are considered undesirable if melted with the ferrous metal during the recycling process. In the above-described processing cutting torches such as “burning bars” and “powder torches” can be used for preparing stainless steel, heavy metal sections such as pit scrap and tundish scrap, and the like, for recycling processes.  
         [0003]     The above-described cutting processes are most often carried out in open-air scrap yards, which process recyclable ferrous metal from scrapped automobiles and appliances, structural members from the demolition of buildings and bridges, rolls from steel mill rolling equipment, and various other sources of ferrous metal suitable for recycling into new steel structures and products.  
         [0004]     During preparation of the above-described scrap, with use of the various cutting torches, air-borne pollutants are generated, not only from combustion of the cutting gases and oxidation of the ferrous metals, but from oxidation of non-ferrous metals and other materials which may be incorporated with the metal being cut. The above-described air-borne pollutants are harmful to the environment, and emission of those pollutants to the atmosphere is strictly regulated by government agencies.  
         [0005]     Although the present invention is described in relation to use in processing scrap metal, use in other operations such as sand-blasting, painting, sawmills, etc. is available for the invention.  
       OBJECTS OF THE INVENTION  
       [0006]     It is an object of the present invention to provide a system, for use in a scrap processing operation, to capture air-borne pollutants generated during processing of scrap metal.  
         [0007]     It is another object of the present invention to provide a system which does not interfere with the traditionally practiced processes for placement of scrap to be processed, with use of cranes, mobile loaders, or the like.  
         [0008]     It is a further object of the present invention to provide a system which does not interfere with the traditionally practiced processes for removal of cut and prepared scrap, with use of cranes, mobile loaders, or the like.  
         [0009]     It is still a further object of the present invention to collect the air-borne pollutants for convenient disposal in an environmentally safe manner.  
       SUMMARY OF THE INVENTION  
       [0010]     The present invention is a track-based mobile system for use with metal cutting processes generating air-borne pollutants, for preventing contamination of the atmosphere. The system has a track connecting a plurality of freely accessible spaced-apart work sites, for placement of workpieces, upon which processes generating air-borne pollutants are carried out; an enclosure providing an enclosed space for any one of the work sites and associated workpieces, to contain air-borne pollutants, generated from processing the associated workpieces, within the enclosed space, a filtering means, communicating with the enclosed space, for removing the air-borne pollutants from the enclosed space, wherein the enclosure and the filtering means are moveable along the track as a single unit supported by the track, and the enclosure is readily openable at opposing portions facing the track, to enable the enclosure to pass over workpieces at the plurality of work sites. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     The invention will become more readily apparent from the following description of a preferred embodiment thereof shown, by way of example only, in the accompanying drawings, wherein:  
         [0012]      FIG. 1  is a plan view of a preferred layout for a scrap yard for utilizing the system of the present invention;  
         [0013]      FIGS. 2 and 3  are drawings of the system of the invention as viewed along the length of the track;  
         [0014]      FIGS. 4 and 5  are drawings of the system of the invention as viewed perpendicular to  FIGS. 2 and 3 .  
         [0015]      FIGS. 6A-6D  are top views of the system of the invention showing examples of air flow patterns which can be set up within the enclosure of the invention.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0016]     The present invention is arranged to be operable in essentially any scrap yard.  FIG. 1  depicts a typical scrap yard, having the present system of the invention incorporated into it. In  FIG. 1 , there is denoted an area  1 , primarily for unprocessed, mixed scrap, which is stockpiled for processing to separate dissimilar metals and cut large members, too large for melting furnaces or the like, into sizes suitable for downstream recycling processes.  
         [0017]     Areas  2   a ,  2   b , and  2   c  denote areas for storing processed scrap which has been cut to a suitable size and separated by metal type for forwarding to recycling processors.  
         [0018]     Between the two above-described areas is located an elongated open work area  3  in which sorting, cutting, and other scrap processing steps can be carried out. It is in this elongated open work area that the system of the invention can be located.  
         [0019]     Although the above-described scrap yard layout is preferred, other layouts can accommodate the system of the invention, as long as a preferably linear track joining open work areas can be located in the scrap yard.  
         [0020]     The system of the invention includes at least two parallel rails extending length wise to form a track for supporting components of the invention, in order that the invention might be used at any of the individual open work areas  3   a - 3   g . In a preferred embodiment, three parallel rails are provided, as shown at  4   a ,  4   b , and  4   c . Although any material upon which wheels can be supported and guided is available in practice of the invention, rails such as those used in the railroad industry, are preferred. The spacing between the rails is determined by the size of the remaining components, which are discussed below. Ideally, space between the rails and outward of the rails toward the storage areas are provided with gravel or are paved to near the top surfaces of the rails so as to provide a safe and workable surface for carrying out the work.  
         [0021]     In  FIGS. 2-5  other components of the invention, which are moveable along the rails, are shown. The system includes an enclosure  5  for surrounding a work area and the material to be processed, to prevent substantially any air-borne pollutants from entering the atmosphere. In use of the invention, the enclosure is first positioned on the rails but out of the way of material handling equipment used to position the material to be processed. The material to be processed is placed at one of the individual open work areas,  3   a - 3   g , within a space defined by rails,  4   a  and  4   b . In further describing the invention, the placed material which is to be processed is referred to as the workpieces. With the enclosure  5  first positioned out of the way, for example near open work area  3   a , any handling equipment traditionally used for handling and sorting scrap can be used without any interference, for example at open work area  3   e . The out of the way location can be at one or the other ends of the track, or in large operations at any point along the track away from the working scrap handling equipment.  
         [0022]     Following positioning of a suitable quantity of workpieces between the rails  4   a  and  4   b , at a selected work area, the enclosure, which includes end walls  6   a  and  6   b , and side walls  8   a  and  8   b , is moved along the rails so as to be located over the selected work area. To enable at least one of the end walls  6   a ,  6   b  of the enclosure to pass over positioned workpieces, openable portions  7   a ,  7   b  are provided in a portion of the respective end walls at a location between the rails  4   a  and  4   b . Preferably both end walls,  6   a  and  6   b  have openable portions  7   a  and  7   b  so that the enclosure is movable along the track, from end to end, and is able to pass over a plurality of different work areas in the process of being filled with workpieces for subsequent processing. The enclosure is moveable with use of a mobile loader, or the like, or the enclosure can preferably be self-propelled by an electric motor or internal combustion engine, incorporated into the system. The motor or engine is engaged with at least one of supporting wheels  9   a - 9   f . In  FIG. 2A , electric motor  10  is shown engaged with supporting wheel  9   a . Preferably two or more supporting wheels are driven.  
         [0023]     Following movement of the enclosure to surround the workpieces, the openable portions  7   a  and  7   b  are at least partially closed in order to contain the air-borne pollutants generated during processing of the scrap. In order to more thoroughly contain the pollutants, seals can be provided along bottom edges of the side walls  8   a  and  8   b . The seals are indicated at  11 , in  FIGS. 2-5 . In a preferred embodiment the seals are of a flexible rubber material which preferably make contact with the ground surface. Although seals can also be provided on bottoms of the openable portions  7   a  and  7   b , a completely air-tight enclosure is not necessary, and the openable portions can be used for controlling make-up air flow and air pressure within the enclosure, which is described below. The openable portions  7   a  and  7   b  of the enclosure  5  are preferably multi-segmented roll-up doors which are motor operable so as to be easily opened and closed when relocating the enclosure and controlling the air flow and air pressure during a metal cutting operation. The roll-up doors preferably are sealed, at their sides where contact is made to the respective end walls  6   a  and  6   b.    
         [0024]     In operation of the system the generated air-borne pollutants are captured so as to be disposed of in a non-polluting, environmentally safe manner. To accomplish such step a filtering system  12  is provided in communication with the space enclosed by the enclosure. The filtering system is arranged to intake air from within the enclosure, which is contaminated with the air borne particles, and exhaust air from which the particles are substantially removed. Preferably the filtered air is exhausted into the atmosphere and provisions for make-up air, such as an intake fan or merely openings in the enclosure are provided. Other modes of operating the filtering system can include a closed system in which all of the filtered air is returned to the enclosure, or a combination of the above two modes, in which a portion of the filtered air is returned to the enclosure and a portion is exhausted to the atmosphere. In a preferred embodiment a slightly negative pressure, in relation to atmospheric pressure, is maintained within the enclosure so as to more surely prevent any contamination of the atmosphere. Such slight negative pressure can be obtained by controlling the volume of air handled by a fan of the filtering system and controlling openings for make-up air.  
         [0025]     The filtering component of the system is selected to incorporate a filtering medium which captures substantially all of the air-borne solid particles. A filtering system having such a medium is a Model GS 24 Dust Collector manufactured by Farr Air Pollution Control, Jonesboro, Ark., 72401. Preferably, in order to operate the system of the invention in a continuous manner, a bank of filters is provided so that some of the filtering medium can be in a collecting mode while remaining filtering medium is in a regeneration mode. Controls can be provided to alternate between the modes in order to operate the filter system in a continuous manner. During the regeneration mode the collected pollutants are dislodged from the filtering medium with use of compressed air or other means and removed from the filtering system in solid form into containers such as  13  to be disposed of in a non-polluting manner. In the preferred filtering system heavy air-borne particles flow directly to a collection bin while remaining particles are collected on surfaces of the filtering medium.  
         [0026]     In the preferred embodiment, all of the above-described filtering and air handling components are attached to the enclosure such as by attached platform  14  to form a single unit which is easily movable along the track. The rail  4   c  is primarily for supporting one edge of platform  14  while another edge of the platform can be supported by the enclosure.  
         [0027]     In order to provide the above-described mobility for the system along the rails and to have electrical power available for the filtering system and electric repositioning motors attached to the wheels, a generator  15  powered by diesel fuel, gasoline, or the like can be incorporated into the system. The generator is preferably located on platform  14  with the filtering system  12 . Other embodiments of the invention can obtain electrical power from power outlets positioned along the rails or a lengthy suspended power cord capable of extending the length of the track. Additional support systems such as electrical breakers and the like, or storage areas can also be located on platform  12 , for example as shown at  16 .  
         [0028]     Use of the various metal cutting torches mentioned above requires a skilled operator, and the working environment can be hot, filled with air pollutants and somewhat dangerous considering the heavy metal workpieces being processed. In view of those undesirable conditions, robotic-like metal cutting torches have been developed and such torches are easily accommodated by the present invention. Although the torches are somewhat automatic, an operator is usually required for remotely controlling the torch. In the system of the present invention, an enclosed control room  17 , in which an operator can control the metal cutting torch, is preferably located along side wall  8   b , with a window facing the work area and workpieces. The control room preferably is sealed from the atmosphere contained by the enclosure. Whether the metal cutting torch is being operated hands-on by an operator or is set up in a robotic-like manner to be operated remotely by an operator in a control room, it is desirable to be able to control the flow patterns of air within the enclosed space. For example if an operator is working in the enclosed space, it is desired to have the flow of contaminated air be directed away from the operator, and into the filtering system by the shortest possible path. Also, if the torch control is being controlled remotely, it is desired that the contaminated air be directed in a path so as not to obscure the view of the workpieces from the operator in the control room  17 . Although the above situations are given as examples, other air-flow patterns may be desired for other reasons.  
         [0029]     Control of the air flow pattern is carried out with use of the enclosure openable portions  7   a  and  7   b , filter system intake tubes  18   a  and  18   b  fitted with dampers  19   a  and  19   b , and filter system exhaust tubes  20   a  and  20   b  fitted with dampers  21   a  and  21   b , shown in  FIGS. 2-5 . Directional arrows on the tubes indicate the direction of air flow when activated.  
         [0030]     Referring to  FIGS. 6A-6D , which are top views of the enclosure  5  and platform  14  of the system, various air flow patterns are shown for various configurations of the invention. In  FIGS. 6A-6D , the workpieces being processed are depicted at  22 . The status of the openable portions of the end walls,  7   a  and  7   b , and the dampers  19   a ,  19   b ,  21   a  and  21   b  are indicated as being opened or closed. It is to be understood that other air-flow patterns are possible, mainly by partially opening or closing the above listed components. Additionally, the volume of air processed by the filtering system can be varied by controlling the speed of the air handling fan associated with the filtering system.  
         [0031]     In  FIG. 6A , damper  21   b  is closed and damper  21   a  is opened so as to exhaust all of the filtered air to the atmosphere. Also, damper  19   a  on intake tube  18   a  is opened, and damper  19   b  on intake tube  18   b  is opened. With such an arrangement the generated air-borne particles are drawn into both intake tubes  18   a  and  18   b . With the above-described configuration, specifically with the filtered air being exhausted to the atmosphere, it is necessary to have openings into the chamber for make-up air. In the configuration of  FIG. 6A  the openable portion  7   a  of end wall  6   a  and the openable portion  7   b  of end wall  6   b  are partially opened and the general pattern of air flow to carry the air borne pollutants to the filter system is depicted at  23 .  
         [0032]     In  FIG. 6B , damper  21   b  is open and damper  21   a  is closed so as to direct all of the filtered air back into the enclosure  5 . Also damper  19   a  on intake tube  18   a  is opened and damper  19   b  on intake tube  18   b  is opened. With such an arrangement the generated air-borne particles are drawn into both intake tubes  18   a  and  18   b . Since the filtered air is not being exhausted to the atmosphere, it is not necessary to have a source of make-up air and openable portions  7   a  and  7   b  of end walls  6   a  and  6   b  can be positioned closed.  
         [0033]     Although substantially 100% of recycled air is possible with the configuration depicted in  FIG. 6B , if a torch operator is within the enclosure  5 , introduction of a small percentage of outside air is advisable. The configuration of  FIG. 6B  is preferred for the comfort of an operator when operating on cold winter days, as the temperature of the air within the chamber is increased by heat from the metal cutting process. Additionally, heaters (not shown) can be provided in the system to further increase the temperature within the chamber.  
         [0034]      FIGS. 6C and 6D  show various other configurations which are possible to control the flow pattern of air-borne particles in order to improve the operability of the cutting process, as discussed above. In  FIGS. 6C and 6D  the status of the various dampers and operable portions are indicated and the associated air-flow patterns are depicted at  23 .  
         [0035]      FIGS. 6A-6D  are solely a few examples of many combinations possible for the dampers and openable portions. Many other combinations are possible in order to provide suitable air-flow patterns for various operating conditions.  
         [0036]     Although the system is described with use of a single enclosure on the track, multiple enclosures are possible to efficiently process large quantities of material.  
         [0037]     While specific materials, dimensional data, etc. have been set forth for purposes of describing embodiments of the invention, various modifications can be resorted to, in light of the above teachings, without departing from Applicant&#39;s novel contributions; therefore in determining the scope of the present invention, reference shall be made to the appended claims.