Abstract:
Components of crushed fluorescent lamps are conveyed pneumatically from a lamp crusher housing to a cyclonic hopper and enter tangentially into the hopper adjacent its upper end. The components include heavy glass particles and caps which are allowed to drop by gravity into a separator housing where they are separated from each other and discharged into different storage containers. Lighter glass particles and dust are recirculated from the upper end of the hopper back to the crusher housing. A vacuum source draws dust and vapors pneumatically from the bottom of the hopper and introduces them tangentially into a cyclone filter housing where particulate matter is allowed to drop into a dust collector. This vacuum source also draws lighter dust and vapors from the upper end of the cyclone filter housing to a dust and mercury filter. Mounted in the crusher housing is a paddle element which rotates adjacent lamp crusher blades and mechanically sweeps lamp components towards the crusher housing outlet.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to fluorescent lamp crushing apparatus, and more particularly to an improved method and associated apparatus for simultaneously separating and delivering to separate containers components of crushed fluorescent lamps and the like, such as end caps, fluorescent powder and glass. 
     Fluorescent lamps in tubular form are the dominant indoor light source for offices, shops, laboratories and industrial plants. While they are produced and employed in linear, circular and U-shaped configurations, the mainstay of tubular fluorescent lamps appear to be four foot and eight foot long linear fluorescent tubes, which have diameters of 1.5 inches (38 m.m.). Lamps of the type described have a lifetime Of about 8,000 to 10,000 operating hours. Typically they last from one to three years depending upon the use cycle. In some shops and offices replacement of failed lamps is performed on a demand basis—i.e., when the ends of the lamps turn black and reduced output is noted. In many other situations, and particularly in large office complexes and manufacturing plants, fluorescent lamp replacement for a whole floor or area is performed on a scheduled basis, when the affected lamps are known to have been in service for a specific period of time. In each situation, a rather significant spatial volume of spent fluorescent lamps quickly accumulates and requires disposal. 
     One solution for disposing large volumes of such lamps is to employ machines which safely crush the lamps into near powder form. Several such lamp crushers are disclosed, for example, in U.S. Pat. Nos. 4,655,404, 5,205,497 and 5,575,429, each of which patents is owned by the assignee of the present application. As disclosed in those patents, the discharge ends of the respective crusher machines usually communicate with 55 gallon drums which receive the crushed components, while mercury vapors and the like that are discharged upon the crushing of the lamps are being accumulated in associated filter mechanisms. Lamps of the type described contain mercury, portions of which when the lamps are crushed, are retained by the above-noted filter mechanisms, but residual mercury in the crushed lamps can constitute a health hazard when present in significant quantities. For that reason it is customary for the above-noted drums containing the crushed lamps carefully to be sealed for shipment and storage, thereby promoting sound environmental handling of the lamp crushing. 
     Disposal of crushed fluorescent lamps in the manner noted above still represents a long term environmental hazard, since the drums containing lamp waste eventually will rust through, resulting in leakage of their contents to the environment. While this consequent leakage may take some time to occur, recycling of the ingredients of crushed fluorescent lamps is viewed by many environment jurisdictions to be the better and eventually only practical solution. In accordance with the invention disclosed herein, the first step in such recycling process is the mechanical separation of the main ingredients of the lamps—namely, the glass, end caps and the fluorescent powder (halo-phosphate) components. In addition, each such fluorescent tube normally contains a small quantity of metallic mercury, e.g. in the vicinity of 25 to 50 milligrams, which attaches to most components of the lamps, but mainly spreads throughout the fluorescent powder. While U.S. Pat. No. 5,092,527 and 5,492,278 have disclosed apparatus for crushing fluorescent lamps and separating the components thereof, such prior art equipment has proved to be unsatisfactory in connection not only with the efficiency of the crushing of layers and the separation of components, but also in connection with the rate at which lamps can be crushed and separated. 
     Accordingly, it is an object of this invention to provide a novel method of separating the constituant components of the crushed fluorescent tubes into end caps, fluorescent powder and glass, near or adjacent to their points of origin in the lamp crushing cycle, thereby to maximize the ability to compact and thus ease subsequent handling of the components. In this way each of the various components may be treated or otherwise handled or disposed of by machinery which forms no part of this invention, and which may be capable of recovering the mercury and purifying the residues so that the latter may serve as the raw materials for new fluorescent lamps. 
     Still another object of this invention is to provide improved lamp crushing apparatus having associated therewith a novel separating mechanism which separates and delivers various components of the crushed lamps to separate containers for use as raw materials in the production of new lamps. 
     Other objects of the invention will be apparent hereinafter from the recital of the appended claims when read in conjunction with the accompanying drawings. 
     SUMMARY OF THE INVENTION 
     To convey the components of crushed fluorescent lamps from lamp crusher housing to a cyclonic hopper, a duct is connected at one end to an outlet of the crusher housing and at its opposite end the hopper adjacent its upper end. A large blower has an outlet connected to the duct to blow air through the duct in the direction away from the crusher housing and toward the hopper thereby generating a vacuum at the crusher housing outlet and pneumatically conveying the lamp components tangentially into the hopper, where the heavier glass particles and caps are allowed to drop by gravity into a separator housing where they are separated from each other and discharged into different storage containers. The upper end Of the hopper is connected to the inlet of the fan so that lighter glass particles and dust are recirculated back to the crusher housing. Another vacuum source draws dust and vapors pneumatically from adjacent the bottom of the hopper and tangentially into a cyclone filter housing where particulate matter is allowed to drop into a dust collector, and draws lighter dust and vapors from the upper end of the cyclone filter housing to a dust and mercury filter. In addition to rotating crusher blades the crusher housing contains a paddle element which rotates with the blades and mechanically sweeps lamp components towards the crusher housing outlet. 
    
    
     THE DRAWINGS 
     FIG. 1 is a front elevational view of lamp crushing and separating apparatus made according to one embodiment of this invention with arrows being employed to illustrate the direction of travel of air circulating through the apparatus; 
     FIG. 2 is a slightly enlarged fragmentary sectional view of this apparatus taken along the line  2 — 2  in FIG. 1 looking in the direction of the arrows, and with portions thereof being shown in full; 
     FIG. 3 is a fragmentary plan view of this apparatus; 
     FIG. 4 is an enlarged fragmentary view of the portion of the lamp feed pipe enclosed in the circle shown by broken lines in FIG. 2; 
     FIG. 5 is an end view looking at the left end of the lamp feed pipe as shown in FIG. 4 but with the lamp removed to show the associated entry door in its closed position; 
     FIG. 6 is a sectional view taken along the line  6 — 6  in FIG. 2 looking in the direction of-the arrows; and 
     FIG. 7 is a sectional view taken along the line  7 — 7  in FIG. 6 looking in the direction of the arrows. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings by numerals of reference,  10  denotes generally a frame having thereon a plane, lamp supporting surface  12  inclined slightly to the horizontal, and registering at its lower edge with one side of the upper run  13  of an endless conveyor belt B. Belt B is mounted to travel about a pair of spaced drive wheels on sprockets  14  and  15 , which are mounted on frame  10  for rotation about a pair of spaced, parallel, horizontal axes, and with the upper run  13  of the belt being spaced beneath a narrow ledge or flange  15  which projects from one side of frame  10 . In the embodiment illustrated, a conventional gear mechanism  17  connects the shaft of the forward wheel  14  to the output of an electric motor  18  to be driven thereby in a direction to cause the upper run  13  of the belt to travel toward the right in FIG. 2, and toward a fluorescent lamp crusher denoted generally by the numeral  20 . 
     Crusher  20  comprises a cylindrical crusher housing  22  supported on a frame  21  with its upper inlet end inclined slightly to the vertical. As noted in greater detail hereafter, housing  22  contains a separator paddle and lamp crusher elements which are rotated by a ½ HP drive motor  23  that is mounted on the closed, upper end of the housing, and which is shown in phantom by broken lines in FIG.  2 . Fluorescent lamps L are adapted to be delivered one by one into the path of the crushing elements by a tubular feed pipe  24 , which is sealing secured at one end in and projecting from an inlet opening in housing  22 , and has an open outer end positioned to face incoming lamps delivered by belt B. Pivotally mounted in pipe  24  is a spring-loaded entry door  25  which is momentarily opened by each incoming lamp as described in greater detail; hereinafter. 
     Upon being crushed, the components of the crushed lamps fall downardly in housing  22  to an opening  26  (FIG. 6) in the bottom thereof which communicates with the lower, inlet end of an elongate suction pipe or conduit  27 . Intermediate its ends conduit  27  communicates as at  28  with the discharge end of a blower  29 , which is driven by a ¾ HP electric motor  31 . The blower  29  forces air into the conduit  27  in a direction away from the crusher  20 , and upwardly in FIG. 1 at the rate of approximately 594 CFM (cubic feet per minute) and tangentially into the upper end of a cylindrically shaped cyclonic hopper, which is denoted generally in FIGS. 1 to  3  by the numeral  32 . Hopper  32 , is supported on the upper end of a separator chamber housing  35  which is secured in a frame  34  beneath hopper  32 . Hopper  32  has its lower, discharge end connected by a chute  33  (FIG. 1) with the upper end of the chamber in housing  35 . 
     The blower  29  generates so much airflow upwardly in the conduit  27 , that it creates a very strong vacuum in the bottom of the crusher housing  22 , and in so doing, causes the components of the crushed lamps (crushed glass, end caps and fluorescent powders) to be withdrawn out through opening  26  of the housing  22 , and to be conveyed upwardly to the hopper  32  for delivery to the separator chamber housing  35 . The same vacuum, of course, also creates within the crusher housing  22  a constant vacuum which causes the crushed components of lamps to drop downwardly in the housing  22  for delivery to the separator chamber in housing  35 . 
     Housing  35 , which is generally triangular in cross-section, comprises a pair of spaced, parallel sidewalls  36  and  37 , an inclined top wall  38 , a vertical endwall  39 , and a bottom wall  40  inclined at an acute angle to the upper wall  38 . At opposite ends of its bottom wall  40  the housing  35  has formed therein two spaced, parallel, vertically extending outlet chutes  42  and  43 , respectively, which communicate with the upper ends of waste collecting drums  44  and  45 , respectively, that are supported on pallets P. As taught by the above-noted U.S. Pat. No. 5,205,497, the upper ends of the containers  44  and  45  are releasably connected to the lower ends of the associated chutes  42  and  43 , respectively, by elongate, plastic sleeves  47  to prevent any accidental escape of toxic materials discharged from housing  22 . 
     The components that are conveyed upwardly through chute  27  are discharged from housing  32  into the upper end of the housing  35 , whereby the solid particles therein (end caps and crushed glass) fall onto the upper surface of an elongate separation screen  51  (FIGS.  1  and  3 ), which is secured to and extends between the sidewalls  36  and  37  of housing  35  in spaced, parallel relation to the top wall  38  of the housing. Screen  51 , which is engaged at its underside by a viberator  52 , functions to separate the ground glass chips from the end caps, by enabling the ground glass to pass downwardly through the screen  51  and onto the bottom wall  40  of the housing  35 , from whence the chips gradually slide downwardly into the chute  43  and hence into the container  45 . The larger crushings or lamp components which are conveyed into the upper end of housing  35 , such as the end caps, which are comprised mainly of aluminum, some plastic insulation, connecting wires and filaments, slide down the screen  51  and drop through the chute  42  into the container  44 . 
     To remove any dust or vapors contained in the crushings or waste components that enter the housing  32 , the upper wall of its discharge chute  33  has therein a dust and vapor outlet that is connected to one end of a dust conveying duct  55 . Duct  55  extends upwardly over the top of housing  35  and downwardly at its opposite end into an opening formed in the periphery of a cylindrically shaped dust cyclone filter housing  56  adjacent the upper end thereof, so that dust and vapors enter tangentially into housing  56 . Housing  56  communicates at its lower end with a dust collector pail  57  into which dust and particulate matter drop by gravity after entering housing  56 . Secured at one end coaxially in the cylindrically shaped upper end of housing  56  is a duct  58 , the opposite end of which is releasably and sealingly secured in an opening in the upper end of a filter housing  60  to communicate with its filter. Housing  60 , which contains a dust and mercury filter, is secured by a bracket  61  to one side of frame  34 , and is connected at its lower end to the inlet  62  of a suction fan or blower  63 , which generates a vacuum in the filter housing  60  and duct  58 . Blower  63  is driven by ⅓ HP motor  64 , and has an exhaust side which opens on and exhausts to the atmosphere. The tangential entry of dust and air into housing  56 , and the central upward exit of air from the housing by duct  58  promotes dust separation in housing  56  by centrifugal and gravity action. 
     In practice, blower  63  draws dust and mercury laden air from the lower end of housing  32  and through the filter housing  60  at the rate of approximately 239 CFM. At the same time, a substantially larger quantity of air, on the order of 330 CFM, is recirculated from the top of housing  32  back to the inlet of the blower  29  by a larger duct  65 , which is secured at one end in the upper end of housing  32 , and at its opposite end in the inlet to blower  29 . Adjacent the inlet of blower  29  duct  65  is connected by a smaller duct  66  to the upper end of a still smaller pipe or duct  67  the lower end of which is connected to a circular opening  68  (FIG. 2) formed in the inner end of the feed pipe  24  to communicate with the interior of crusher housing  22  by the same opening through which lamps L enter such housing. Notably, the inlet to the recirculating duct  65  has been placed such that the air entering that duct from housing  32  enters at a right angle compared to the travel of air entering from conduit  27  into the housing  32 , thus minimizing the entrapment of any chips or other particles in the air that is recirculated through the ducts  65 ,  66  and  67  to the crusher housing. 
     Referring now to FIGS. 2,  4  and  5 , it will be noted that the spring-loaded door  25  in feed pipe  24 , while generally circular in configuration, is smaller in diameter than the internal diameter of pipe  24 . The door  25  which is pivotally mounted in pipe  24  by a pin  71  and associated spring  72 , normally is urged by the spring into a closed position in which it extends transversely of the bore in pipe  24 . In this position, as shown in FIG. 5, its peripheral surface is slightly spaced radially from the inner peripheral surface of pipe  24 , thus leaving a nearly annular space  73  for permitting air travel at all times through pipe  24  into housing  22 . As noted hereinafter, lamps L entering the feed tube  24  engage and urge door  25  to its open position (broken lines in FIG. 4) as the lamps are fed into housing  22 . 
     In use, a supply of fluorescent lamps L that are to be crushed, are placed upon the inclined surface  12  of the frame  10 , with the lowermost lamp or lamps rolling onto the upper surface of the upper run  13  of the conveyor belt B. The lamps may be anywhere from up to four feet to eight feet in length, and depending upon the overall length of the support surface  12  and the conveyor belt B, one or more lamps may move by gravity downwardly, and possibly one behind the other, onto the upper run  13  of the belt B. When the belt is operated, lamps L are fed successively into the flared open end Of the feed pipe  24  where they engage and open the normally closed door  25 , and are inserted into the path of rotating crusher elements in housing  22 . During this time also, of course, the blower  29  is operated so that air and broken lamp fragments are drawn upwardly through duct  27  and are introduced into the hopper  32 . At this time also, of course, the air from the blower  29  is recirculated through the duct  65  to the inlet of the blower  29 , and through duct  66 , pipe  67  and the opening  68  in the feed pipe  24 , so that air is constantly circulated through housing  22  and the hopper  32 . Also at this time the vibrator  52  is operated, as is the motor  64  for the suction fan  63 , which operates, as noted above, to draw dust and particulate matter into the cyclone filter housing  56  and to draw dust and mercury through duct  58  to the filter contained in the filter housing  60 . During such operation of the apparatus, of course, ground glass chips, and the like, which enter housing  35  from the hopper  32 , are allowed to pass downwardly through the screen  51  to container  45 , while the lamp end caps, plastic insulation, connecting wires and the like, slide down the screen  51  and drop into the container  44 . 
     A central purpose for the exhaust blower  62  is the maintenance of a slightly negative pressure within the machine and its attachments (drums  44 ,  45 , pail  57 , crusher  22 , etc.) at all times, such that dust and Mercury vapors will not escape from the machine. The internal negative pressure forces outside air to leak into the machine at all less than perfectly sealed seams and through the annular space  73  (FIG. 5) at the point of tube entry. This leaked-in air will pick up dust and Mercury vapors on its way to the exhaust blower. The filter in housing  60 , partially fiber for dust capture and partially activated charcoal, removes the dust and vapors to insure the exhausting of acceptable air. 
     To supplement the action of the blower  29 , which draws air, vapors and broken lamp fragments from the crusher housing  22  into duct  27 , housing  22  is provided with separator paddle mechanism which helps to discharge vapors and fragments into duct  27 . As shown in FIGS. 2 and 6, the output of motor  23  is drivingly connected to one end of a crusher shaft  75 , the opposite end of which is drivingly connected in housing  22  to one end of a paddle driving shaft  76 , the opposite end of which is rotatably journaled in a bearing (not illustrated) in the closed end of housing  22 . A plurality (three in the embodiment illustrated) of similarly shaped crusher blades  77  are secured medially of their ends to shaft  75  for rotation thereby coaxially in housing  22  adjacent its upper, open end through which lamps L enter the housing. Secured medially of its ends to shaft  76  for rotation thereby beneath blades  77  is an elongate metal plate  78  having secured to and projecting downwardly from opposite ends thereof a pair of rectangularly-shaped blades  79 . When driven by motor  23 , shafts  75  and  76  rotate the crusher blades  77  to crush lamps, and plate  78  and paddles  79  in the same direction to help sweep or urge crushed glass and vapors through opening  26  and into duct  27 . 
     To protect housing  22  and to supplement the effect of the crusher blades  77 , housing  22  has removably mounted coaxially in the upper end thereof beneath its cover  81 , and in radially spaced relation to the outer ends of blades  77  an annular impact shield  82  made of relatively thick steel (e.g.{fraction (3/16)}″). The circular lower edge of shield  82 , which is axially spaced above the paddle plate  78 , is releasably seated on a circular bracket  83  that is secured coaxially to and projects radially from the inner peripheral surface of housing  22  intermediate the ends thereof. To assist the blades  77  in the pulverizing of small glass chips and end caps, a plurality (twelve in the embodiment illustrated) of elongate, narrow, steel baffles  85  are secured to, as by welding, and project slightly from the inner peripheral surface of shield  82  in angularly spaced relation to each other, and in radially spaced relation to confronting ends of the crusher blades  77 . And as shown more clearly in FIG. 7, the baffles  85 , which may be made from ¼″ square strips of desired length (e.g. 4″), are inclined at approximately 45° to the axis of housing  22  and shaft  75 , so that any particles pulverized thereby during the crusher operation will be guided downwardly thereby into the path of the rotating paddles  79 . 
     From the foregoing, it will be apparent that the present invention provides novel method and apparatus for considerably improving the crushing and separation Of the components of crushed fluorescent lamps tubes in rather large quantities, and also enables recovery of mercury and the purifying of residues that may otherwise serve as raw materials for new lamps. The efficiency of crusher  20  is considerably improved by use of the. removable shield  82  bearing the angularly spaced baffles  85 , which cooperate with blades  77  to increase the pulverization of crushed lamp components, and also assit in directing such components into the path of the rotating paddles  79 . In turn the paddles improve the efficiency with which crushed components are directed toward the crusher housing outlet  26  for conveyance to the cyclonic hopper  32 . 
     While this invention has been illustrated and described in connection with only certain embodiments thereof, it will be apparent that it is capable of further modification, and that this application is intended to cover any such modifications as may fall within the scope of one skilled in the art, or the appended claims.