Patent Publication Number: US-6988683-B2

Title: Apparatus for crushing glass or ceramic material

Description:
FIELD OF THE INVENTION 
   This invention relates to apparatus for crushing glass or ceramic material. 
   BACKGROUND OF THE INVENTION 
   The disposal of glass and ceramic material presents problems. More specifically, apparatus for crushing glass is known. The known apparatus crushes the glass with a view to reducing the volume occupied by the glass so that the glass can then be more easily handled. The crushed glass contains very sharp fragments which make the glass dangerous to handle. This in turn severely restricts any possible further use to which the glass fragments can be put. Currently, commercial uses for crushed glass are limited to asphalt grog for roads, and shot blasting media in small volumes. The vast majority of the crushed glass is simply disposed of as a land fill waste material. Such disposal of the crushed glass is not especially ecologically friendly, and the land fill sites must be such that the crushed glass is buried sufficiently deeply that its sharp edges cannot harm human and animals. Also, there are collection costs for collecting the crushed glass prior to disposal. 
   Ceramic material may also need to be crushed with a view to reducing the volume occupied by the ceramic material so that the ceramic material can then be more easily handled. If the ceramic material is glazed, the crushed ceramic material may contain sharp fragments, which then give rise to the same type of problems as those mentioned above for glass. Some ceramic material is not glazed, but it is often not economically possible to separate glazed and non-glazed ceramic material. 
   SUMMARY OF THE INVENTION 
   It is an aim of the present invention to obviate or reduce the above mentioned problems associated with the disposal of glass and ceramic material. 
   Accordingly, the present invention provides apparatus for crushing glass or ceramic material, which apparatus comprises a rotor, rotor blades on the rotor, at least one stationary blade which cooperates in use with the rotor blades as the rotor rotates, and a chamber for receiving crushed glass or ceramic material, the apparatus being such that the rotor is upstream of the chamber, the rotor is rotated at 1200–2800 revolutions per minute, the glass or ceramic material is fed to the rotor at a feed speed of 3–75 meters per second, the glass or ceramic material is first broken into fragments on impact with the rotor, the fragments are reduced in size and formed into cullet by passing through a gap between the rotor blades and the stationary blade, and the action of the rotor blades and the stationary blade causes the cullet to be such that it will not cut, is safe for handling, and is suitable for further use without further processing. 
   The apparatus of the present invention is extremely advantageous in that the product cullet does not have sharp edges. The cullet can be safely handled without fear of persons or animals being cut. Thus the cullet can immediately be used for a wide variety of purposes and there is no need for the cullet to be used as a land fill waste material. The cullet of the present invention may be used instead of sand on golf greens as a drainage material which allows water to pass through the drainage material. The cullet may also be used as an in-fill material for drainage ditches. The cullet may still further be used as decorative finishes in horticulture, and also as a slug repellant material. Generally, the cullet may be used for a wide variety of purposes, and with the advantage that the cullet is a cheap material that would otherwise have just gone to waste. 
   As indicated above, the rotor is rotated at 1200–2800 revolutions per minute, and the glass or ceramic material is fed to the rotor at a feed speed of 3–75 meters per second. Such rotational speeds for the rotor and such feed speeds for the glass or ceramic material help to produce the required cullet. The rotor may be rotated at, for example, 1550 revolutions per minute. 
   The apparatus is preferably one in which the glass or ceramic material is fed to the rotor at a feed speed of 3–75 meters per second. Such a feed speed is again a preferred contributory factor to producing the required cullet. A presently preferred feed speed is 3 meters per second. However, alternative feed speeds may be used. 
   The apparatus will usually be one in which the rotor is positioned above the chamber. The rotor may however be positioned elsewhere if desired. 
   Preferably, the stationary blade is an adjustable stationary blade for the purpose of adjusting the gap between the rotor blades and the stationary blade in order to vary the size of the cullet. Cullet of different sizes may have different further uses. For example, cullet for use in place of sand on golf greens will generally be of a smaller particle size than cullet for use in drainage ditches. 
   The apparatus of the invention may include retention seals for retaining dust in the chamber. The dust is formed as a result of the crushing of the glass or the ceramic material. The dust is generally formed of silica in the case of crushing glass. The retention seals may be located around a drive shaft for the rotor. 
   The apparatus of the present invention may also include drive means for the rotor. The drive means may be hydraulic, electrical, electromechanical, belt drive or gear drive. Any suitable and appropriate type of drive means may be employed. 
   The apparatus of the present invention may include a feed chute along which the glass or ceramic material passes for correct presentation to the rotor. In one embodiment of the present invention, the feed chute is an elbow feed chute. Such a feed chute may be designed for the manual feeding of bottles and it is preferably designed such that a person cannot put their arm so far into the feed chute that the rotor can be engaged. 
   Preferably, the feed chute includes a lining for preventing erosion of the feed chute adjacent the rotor. The lining is thus able to deal with the effects of the imploding glass or ceramic material in the region of the feed chute adjacent the rotor. Preferably, the lining is a ceramic lining, a composite lining, or a wear-resistant steel lining. Other types, of lining may however be employed. 
   The apparatus of the present invention may include feed means for feeding the glass or ceramic material to the rotor. Depending upon the type of construction of the apparatus, the feeding may be by gravity feeding or force feeding. The gravity feeding can be done manually. The force feeding can be done by a conveyor or a bucket on a vehicle such as a tractor. 
   The apparatus of the present invention may include cullet grading means for grading the cullet into different predetermined particle sizes for different predetermined further uses. 
   The cullet grading means may be a rotary screening device, or a vibration screening device. Other types of cullet grading means may be employed. 
   The apparatus of the present invention may include filter means for removing dust from the apparatus. The dust will usually be silica dust in the case of glass being crushed by the apparatus. 
   The filter means may remove the dust firstly at a base part of the crushing chamber, and secondly at the grading screens when grading screens are employed. 
   The apparatus may include conveyor means for conveying the graded cullet to a storage container. 
   The apparatus may include re-circulating means for re-circulating graded cullet of a certain particle size for re-processing into cullet of a smaller particle size. 
   The apparatus may include filter means for filtering any fluid contained in the glass or ceramic material prior to crushing, the filter means being such as to separate contaminates from water whereby the water can be freely discharged to waste. For example, the glass initially delivered to the apparatus of the present invention may be in the form of bottles containing contaminates such for example as alcohol or oil. Such contaminants cannot be discharged down normal local drainage systems and so they need to be separated. By separating them from the water, the water can be discharged and only the relatively small volumes of contaminants need to be retained for specialised disposal. 
   The apparatus may include a pre-breaking device for breaking up large pieces of glass or ceramic material before the glass or ceramic material is introduced to the remainder of the apparatus for crushing. The use of the pre-breaking device is advantageous where the glass or ceramic material is initially in the form of large sheets which are oversize for feeding to the rotor. 
   The pre-breaking device may be a crusher or a shredder. Other types of pre-breaking device may be employed. 
   The apparatus may include a ferrous/non-ferrous separator located at the pre-breaking part of the apparatus. 
   The apparatus of the invention may be constructed to be mobile if it is desired to take the apparatus to various sites. Alternatively, the apparatus may be constructed to be stationary in which case the glass or ceramic material has to be brought to the apparatus. Where the apparatus is constructed to be mobile, the apparatus may include coupling means for coupling the apparatus to a vehicle, thereby allowing for easy use of the apparatus in more isolated areas. 
   The apparatus may be one in which there is one of the rotors for each one of the chambers. Alternatively, the apparatus may be one in which there are two or more of the rotors for each one of the chambers. The number of rotors is chosen to give the required crushing surface between rotor blades and stationary blade. 
   The apparatus may include a cleaning stationary blade which operates to clean the rotor blades with a scraping action as the rotor rotates. 
   The apparatus may include a post process drier for drying the cullet. 
   The apparatus of the present invention is able to operate with glass or ceramic material of a wide variety of types, shapes and sizes. Thus, for example, the glass may be in the form of bottles, jars, windscreen glass, laminate glass, plate glass and window glass. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the invention will now be described solely by way of example and with reference to the accompanying drawings in which: 
       FIG. 1  shows schematically first apparatus for crushing glass; 
       FIG. 2  shows in detail part of the first design of apparatus for crushing glass; 
       FIG. 3  shows a chamber and stationary blade part of the apparatus shown in  FIG. 2 ; 
       FIG. 4  is an exploded view of a rotor and rotor blades as employed in  FIG. 2 ; 
       FIG. 5  shows second apparatus of the invention; 
       FIG. 6  is a side view of third apparatus of the invention; and 
       FIG. 7  is a top view of the apparatus shown in  FIG. 6 . 
   

   DETAILED DESCRIPTION OF THE DRAWINGS 
   Referring to  FIGS. 1–4 , there is shown first apparatus  2  for crushing glass. The apparatus  2  comprises a rotor  4 , rotor blades  6  on the rotor, and a stationary blade  8  which co-operates in use with the rotor blades  6  as the rotor  4  rotates. As can be seen from  FIGS. 2 and 4 , the rotor blades  6  are separately formed from the rotor  4  and they are secured to mounting portions  10  of the rotor  4  by bolts  12  which pass through holes  14  in the rotor blades  6 . The bolts  12  may alternatively be clamps (not shown). 
   The apparatus  2  also comprises a chamber  16  for receiving crushed glass. As can be seen from  FIGS. 1 and 2 , the rotor  4  is upstream of the chamber  16  by being mounted above the chamber  16 . 
   As can be seen from  FIG. 1 , glass in the form of bottles  18  is fed to the apparatus  2 . The glass in the form of the bottles  18  is first broken into fragments  20  on impact with the rotor  4 . The glass fragments  20  are then reduced in size and formed into cullet  22  by passing through a gap  24  between the rotor blades  6  and the stationary blade  8 . The action of the rotor blades  6  and the stationary blade  8  causes the cullet  22  to be such that it will not cut, is safe for handling, and is suitable for further use without further processing. 
   During use of the apparatus  2 , the rotor  4  rotates at 1750 revolutions per minute. Bottles  18  are fed to the rotor at a feed speed of 60 meters per second. The glass bottles  18  can be fed manually or automatically. As can be seen from  FIG. 1 , the glass bottles enter the apparatus  2  and are directed towards the rotor  4  by a chute  26 . The glass bottles  18  fall under gravity down the chute  26  until they strike the rotor  4  whereupon they implode. The imploded glass fragments drop down on to the rotor  4  and pass through the gap  24  where they are further reduced in, size to the cullet  22 . 
   The stationary blade  8  is an adjustable stationary blade  8 . Thus the size of the cullet  22  is able to be controlled by moving the stationary blade  8  towards or away from the rotor blades  6  in order to vary the size of the gap  24 . By appropriately varying the size of the gap  24 , the cullet  22  is able to be reduced in size right down to a powder if desired. 
   As shown in  FIGS. 2 and 3 , the chamber  16  is in a housing  28 . The housing  28  has an upper edge  30  and a pair of recesses  32  in the upper edge  30 . The recesses  32  receive a shaft  34  of the rotor  4 . The recesses  32  are provided with retention seals  36  for retaining dust from the cullet  22  in the chamber  16 . Without the retention seals  36 , the dust could escape from the chamber  32  through the recesses  32  and along the side of the shaft  34 . 
   As shown in  FIG. 1 , the apparatus  2  includes drive means  38  for driving the rotor  4 . The drive means  38  comprises an electric motor  40  having a drive shaft  42 . The drive shaft  42  supports a pulley  44  which drives an endless belt  46 . The endless belt  46  drives a pulley  48  which is mounted on the shaft  34  of the rotor  4 . Thus rotation of the pulley  48  via the endless belt  46 , the pulley  44  and the electric motor  40  causes rotation of the rotor  4 . 
   As shown in  FIGS. 2 and 3 , the stationary blade  8  is held in position by bolts  50 . Adjustment of the stationary blade  8  is effected by releasing the bolts  50 , adjusting the stationary blade  8  to the required position, and then re-tightening the bolts  50 . This adjustment movement is illustrated by arrow  52  in  FIG. 3 . 
   As can be seen from  FIGS. 2 and 3 , the apparatus  2  is provided with a cleaning stationary blade  54  which operates to clean the rotor blades  8  with a scraping action as the rotor  4  rotates. The cleaning stationary blade  54  helps to remove glass fragments from the edges of the rotor blades  6 , and thereby helps to make sure that the balance of the rotor is maintained. The rotor blades  6  are then able to act more efficiently in grinding the glass fragments  20  to remove sharp edges from the glass fragments  20  so that the cullet  22  can be handled safely without fear of persons or animals being cut by the cullet  22 . 
   The chute  26  is provided with a lining (not shown) adjacent the rotor  4 . The imploding glass has a tendency to erode the chute  26  and the lining helps to prevent this erosion. The lining may be a ceramic lining, a composite lining, or a wear-resistant steel lining. 
   As can be seen from  FIG. 1 , the entire apparatus  2  is in a cabinet  56  which can be free-standing and which is arranged for receiving the bottles  18  manually through an opening  58 . The bottom of the cabinet  56  may be provided with a pull-out drawer  60  which is pulled out when full and which contains the cullet  22 . 
     FIG. 5  shows second apparatus  62  having a cabinet  64  which is similar to the cabinet  56 . The apparatus  62  has a chute  66  which is curved as shown, instead of the straight chute  26  shown in  FIG. 1 . The chute  66  is an elbow feed chute. The design of the chute  66  is such as to prevent a person being able to insert their arm sufficiently far down the chute  66  to engage the rotor  4 . Similar parts in  FIGS. 1 and 5  have been given the same reference numerals for ease of comparison and understanding. 
   The chute  66  is provided with a door  68  which covers the opening  58  to the chute  66 . The door  68  pivots about a pivot bar  70  and is spring biased by a spring (not shown) to the closed position. 
   The cabinet  64  has a removable rear door  72  for enabling access to the components of the apparatus  62  inside the cabinet  64 . 
   The apparatus  62  is also provided with cleaning means  74 . The cleaning means  74  comprises a tank  76  for containing chemicals. A pump (not shown) is able to pump chemicals for cleaning and disinfecting the chute  66 . The cleaning means  74  is automatically controlled by timed electrical control means (not shown). 
   Referring now to  FIGS. 6 and 7 , there is shown third apparatus  78  of the invention. 
   The apparatus  78  includes two of the rotors  4 . The rotors  4  are powered by two electric motors  40  and endless belts  46 . 
   The rotors grind glass fragments  20  into cullet  22  as described above so that the cullet  22  falls into a chamber  16 . Cullet from the chamber  16  is able to be graded by cullet grading means  80 . The cullet grading means  80  comprises a plurality of different grading screens  82  for grading the cullet  22  into different pre-determined particle sizes for different pre-determined uses. The grading screens  82  are vibrated by vibration means including an electric motor  84 . The graded cullet is collected in sacks  86 . 
   The apparatus  78  includes feed means  88  for feeding the glass to the rotor. The feed means  88  comprises a conveyor  90  which is fed with the glass from a feed hopper  92 . Glass is fed to the feed hopper  92  via a bucket  94  on a tractor  96  which performs the function of a mechanical shovel. 
   The apparatus  78  includes filter means  98  for removing dust from the cullet  22 . If desired, the filter means  98  may remove dust firstly at a base part of the chamber  16 , and secondly at the grading screens  82  as shown in  FIGS. 6 and 7 . 
   The apparatus  78  includes re-circulating means  100  as shown in  FIG. 7 . The re-circulating means  100  includes a re-circulating conveyor  102 . The re-circulating means  100  is able to re-circulate graded cullet of a certain particle size for re-processing into cullet of a small particle size. 
   It is to be appreciated that the embodiments of the invention described above with reference to the accompanying drawings have been given by way of example only and that modifications may be effected. Thus, for example, the apparatus of the invention may include fluid filter means for filtering any fluid contained in the glass prior to crushing, the fluid filter means being such as to separate contaminants from water whereby the water can be freely discharged to waste. The apparatus of the invention may also include a pre-breaking device for breaking up large pieces of glass which are too large easily to be handled by the remainder of the apparatus of the invention. For example, the apparatus  78  shown in  FIGS. 6 and 7  may be provided with a pre-breaking device in the form of a crusher or a shredder prior to the feed hopper  92 . The apparatus  78  shown in  FIGS. 7 and 8  is basically a stationary apparatus. The apparatus  2  shown in  FIGS. 1–4  and the apparatus  62  shown in  FIG. 5  can be constructed to be stationary or movable as may be desired. The apparatus of the invention may be used for crushing any suitable and appropriate type of glass including bottles, jars, windscreens, laminated glass, plate glass and window glass. The apparatus of the invention may also be used for crushing any suitable and appropriate type of ceramic material. 
   The apparatus of the invention as shown in the drawings is advantageous in that it enables large amounts of glass and ceramic material which would normally be thrown away as dangerous waste in land-fill sites, to be processed and re-used in a wide variety of applications in complete safety and without the need for further processing.