WO1995025593A1

WO1995025593A1 - Improvements in and relating to crushing apparatus

Info

Publication number: WO1995025593A1
Application number: PCT/GB1995/000590
Authority: WO
Inventors: David Charles Evans; Allan Tweddle; Christopher Thain Tweddle
Original assignee: David Charles Evans; Allan Tweddle; Christopher Thain Tweddle
Priority date: 1994-03-18
Filing date: 1995-03-17
Publication date: 1995-09-28
Also published as: GB9405372D0; AU1899695A

Abstract

Crushing apparatus for environmentally unacceptable crushable waste, which apparatus comprises: (i) guide means (20) adapted to receive waste for crushing, (ii) crushing means (40) for receiving waste from said guide means (20) and crushing the same, and (iii) receiving means (80) for receipt of crushed waste, wherein said crushing means comprises at least two rotatable crushing members (41, 42), the arrangement being such that the guide means (20) serves to introduce waste to be crushed substantially between the members (41, 42) whereby the said members coact one with another to effect crushing of the waste.

Description

IMPROVEMENTS IN AND RELATING TO CRUSHING APPARATUS

This invention relates to crushing apparatus and has particular reference to apparatus for crushing light bulbs and fluorescent tubes.

Certain categories of household and industrial waste are known to occupy unnecessary space in landfill sites, and it is desirable to reduce such waste to a fraction of its original volume. Examples of this type of waste are electric lamps and fluorescent tubes. However, lamps and fluorescent tubes present safety and environmental hazards on disposal: there is a risk of personal injury from glass fragments, and the breaking or crushing of such items results in the release of toxic metals and vapours.

Numerous attempts have been made to destroy lamps and tubes safely and efficiently. United States Patent 3,913,849 for example discloses a digester for fluorescent tubes, in which digester, fluorescent tubes are broken up by the action of a rotating blade. The rotating blade creates an air stream which flows into the body of the digester and prevents, to an extent, the release of environmentally unacceptable vapours into the atmosphere.

United States Patent 4,607,798 discloses a lamp crushing machine in which there is mounted a drum having a plurality of vanes. Lamps and tubes are progressively broken by the shearing action of the vanes as they pass close by the edges of adjacent walls which project inwardly from the machine casing.

In the above-mentioned prior art documents, lamp-breaking takes place between the respective machine casing and the rotating drum or blade. Among the problems encountered with such arrangements is blockage caused by waste material becoming lodged between the blade or vane and the machine casing. Furthermore, it is difficult to seal such apparatus against leakage of vaporous or gaseous material released during crushing.

There is therefore a need to overcome the disadvantages of known crushing machines, and to provide crushing apparatus which allows safe and efficient crushing of waste material while complying with environmental legislation.

According to one aspect of the present invention, there is provided crushing apparatus for environmentally unacceptable crushable waste, which apparatus comprises: (i) guide means adapted to receive waste for crushing,

(ii) crushing means for receiving waste from said guide means and crushing the same, and

(iii) receiving means for receipt of crushed waste,

characterised in that said crushing means comprises at least two rotatable members, the arrangement being such that the guide means serves to introduce waste to be crushed substantially between the members whereby the said members coact one with another to effect crushing of the waste.

Optionally, separator means may be provided to separate different types of crushed waste.

The guide means may be separable from, or integral with the apparatus, and may be dimensioned so as to be capable of receiving, for example, entire fluorescent tubes and lamps of various shapes and sizes. The waste to be crushed may be introduced manually into the guide means or automatically, for example via a conveyor belt. The guide means may comprise one or more entrance ports, and may be oriented so that at least one entrance port is in a plane above the crushing means. Waste matter may thus fall or slide down the guide means under gravity towards the crushing members.

Where a plurality of entrance ports is provided, each port may serve to receive a different category of waste. The guide means may, for example, comprise an entrance port for fluorescent tubes, an entrance port for television and computer monitor tubes, and an entrance port for other lamps and bulbs. Thus, waste matter may be introduced into the crushing apparatus either sorted or unsorted.

The guide means serves to guide the waste matter to be crushed towards and substantially between the crushing members. In one embodiment the guide means may be in the form of a chute.

The crushing means comprises at least two crushing members. Each crushing member may be any convenient shape, for example in the form of a drum or a rotor. Said members may be identical with, or different from, one another. In one embodiment of this invention, the crushing means comprises two substantially cylindrical members mounted so that crushing of waste takes place between the two said members.

In a particular aspect of the invention, each crushing member may comprise a central longitudinal axis about which there is a plurality of longitudinally-disposed radial vanes. In a preferred embodiment the vanes of adjacent crushing members may be adapted at least partially to intermesh.

Each crushing member may be mounted on an axle extending over substantially the width of the crushing apparatus. The spacing between adjacent crushing members may be adjustable, and depends on the nature of the waste material to be crushed. This spacing may be between about 5mm and about 20cm.

In another embodiment, the members may be skewed one with respect to the other so that the spacing therebetween increases from a first end to a second end. In this embodiment where vane like elements are provided, the radial extent of the vanes may increase with the increasing separation of the skewed axis of rotation of the members. Alternatively, one or more of the members may be stepped along a longitudinal axis, thereby to produce a number of discrete spacings from the first end to the second end. Combined with a multi-entrance port guide means, these embodiments allow waste material to be introduced to the crushing member at a point along the length of the crushing means where the spacing between adjacent members is at an optimum for effecting crushing of the articles concerned.

One or each of the crushing members may be rotatable and/or driven by motor means. The members may also be operated manually. Typical motor means are pneumatic motors, electric motors or internal combustion engines, which latter are eminently suitable for relatively remote waste disposal sites.

Where motor means are present, drive means may be provided to connect mechanically said motor means to one or more of said crushing members. Said drive means may comprise rotating shaft drive; belt and pulley drive; or chain and toothed gear drive, between said motor means and said one or more crushing members. The direction of rotation of each crushing member may be reversible.

In another aspect a toothed gear train and drive chain may be provided. A drive sprocket drives said drive chain, which chain passes over first and second toothed chain wheels which drive first and second crushing members respectively. The axis of rotation of the second crushing member is adapted to be moveable relative to the first crushing member. Thus the first and second chain wheels may be required to move relative to each other. In order to facilitate this the second chain wheel and associated crushing member may be rotatably mounted at a first end of at least one swinging arm. Said swinging arm is pivoted along its length such that rotation about said pivot may cause said second crushing member to approach or retreat from said first crushing member. A second, opposite, end of said swinging arm is provided with an idler gear over which said chain passes, the arrangement being such that the chain path length, and therefore chain tension is maintained substantially constant as the second crushing member moves. Said gear train may be external too, or internal of, the house for the crushing means. A chain housing may surround the gear train and housing to prevent fouling.

In another aspect of this invention, for ease of maintenance of the crushing apparatus, the crushing members may be removable from said apparatus.

In a further aspect of the invention, a pair of rotatable crushing members is provided in which the members are contra rotating to provide a direction of rotation at the nip between the members which serves to draw an article into said nip for crushing.

In another aspect of this invention, the crushing means may comprise a plurality of pairs of crushing members, whereby a first pair of crushing members in an array have a spacing between them greater than the spacing between the members of a subsequent pair. Thus, in use, the said first pair of crushing members breaks the waste material into medium-sized pieces and the subsequent pair or pairs of crushing members, which may be identical with, or different from the first pair of crushing members, crushes the waste from the first pair of crushing members into smaller pieces. It will be appreciated by the man skilled in the art that various permutations and combinations of crushing rotors are possible.

The crushing apparatus of this invention includes a housing, having a scrubbing chamber through which vapours and crushed waste matter pass before being filtered or before passing into the receiving means.

The receiving means may comprise a single receptacle or a plurality of receptacles adapted to receive crushed waste. A plurality of receptacles is particularly appropriate if the crushed waste has been separated.

The receiving means may be a skip, hopper, bucket or other container into which crushed waste may be collected. It will be appreciated that crushed waste produced in the crushing apparatus of this invention may include glass and metal, the latter comprising filaments and lamp endcaps. The receiving means may be washed with water or other fluid, which may be pumped continuously out of the receiving means, through filtration means and back into the receiving means. The filtration means may comprise a number of filters removably mounted in the water stream and adapted to progressively filter the fluid of waste contaminants or particles. The fluid may include reagents adapted to dissolve, neutralize or absorb said contaminants.

Washing water or other fluid may be pumped within a closed system. Pumping may continue while the crushed waste is removed from the apparatus, and the water or other fluid may be used continuously without refilling. Water or fluid lost, for example through evaporation or by adhesion to the crushed waste, may be made up via a refill port.

In another embodiment, the receiving means comprises a receptacle in which a fine mesh wire basket is suspended. Crushed waste may be removed from the receiving means by removing the mesh basket. A mesh size may be chosen so that on removal of the basket from the receptacle, water or fluid flows through the mesh into the receptacle while crushed waste is retained within the basket.

In another embodiment the receiving means comprises a receptacle in which two wire baskets are removably suspended. The first basket may be mainly for receiving glass waste, and the second may be mainly for receiving metal waste. The mesh of the baskets may be different, as appropriate for the contents. Preferably the meshes are the sized to (i) allow optimum fluid flow whilst (ii) retaining the contents. The second basket may be suspended inside the first, or may lie side by side with the first.

The separator means is preferably between the crushing means and the receiving means, and may comprise any well known separation means used in material reclamation. Such methods include magnetic selection, sieving, airflow separation etc. Said separator may be adapted to sort the waste according to size, or according to material characteristics, or both.

It will be appreciated that for fluorescent lamp tubes and the like the crushed glass will be in the form of slivers or fragments, while the metal end pieces will be substantially whole, but possibly extensively deformed. Sorted waste may be directed to appropriate receptacles in the receiving means. The waste may then be recycled, or disposed of as desired.

In one embodiment, the separator has a top surface to receive unseparated waste from the crushing means. The top surface may comprise a first row of two or more mini- rotors. Mini-rotors as hereafter referred to are scaled down versions of any embodiment of the crushing members described hereinbefore. The mini-rotors may be adapted to contra-rotate with respect to their neighbours in the row. The gap between mini-rotors is large enough to draw in glass fragments, whilst being small enough such that metal end pieces are mainly rejected.

In another embodiment of the separator a second row of at least one mini-rotor may underlie the first row, said second row adapted to further crush said glass fragments. The mini-rotors of the second row preferably intermesh the mini-rotors of the first row, and in this case all the first row mini-rotors may rotate in the same direction, and all the second row mini-rotors may rotate in the opposite direction, the net effect being contra- rotation between adjacent intermeshing first and second row rotors.

The first row and second rows may each be mounted at an angle form the horizontal, the angle being such as to induce said end caps to travel downhill along said top surface towards metal receiving means. Glass waste may fall freely from between the mini-rotors under the influence of gravity to glass receiving means mounted under said first or second rows. In another embodiment, a magnetic field may be provided within the crushing apparatus by permanent magnets and/or electromagnets. Crushed waste may thus be sorted substantially into magnetic and non-magnetic materials by the application of the magnetic field, with non¬ magnetic material passing into one receptacle and with magnetic material being diverted to pass substantially into another receptacle.

Air filter means may be provided to clean waste contaminated air in the apparatus. In one embodiment vacuum or air flow generating means may be connected to the crushing apparatus, or be integral with said apparatus, to withdraw air from the apparatus via filtering means, which may include scrubbing means, in order to filter airborne crushed particles and environmentally unacceptable vapours or gases from the air prior to discharge into the atmosphere. The air filtration means may comprise one or more selective filters. The air filtration means may be adapted to remove vapours containing, inter alia, mercury, strontium, cadmium, sodium and lead. In a particular aspect, three particulate filters are arranged in series. The filter means may further include vapour/odour removal means, such as activated carbon filters, and in particular mercury sensitized carbon. The air flow generating means may serve to displace a stream of air from the environment in which the apparatus is sited into the interior of the apparatus. Preferably the air stream enters via the guide means, flows through the crushing means and over the receptacle(s) of the crushing apparatus. The air flow generating means may be a displacement and/or centrifugal fan. The airflow generating means preferably creates a pressure differential across air filter means, which means extends between the interior of the crushing apparatus and the exterior environment. In this way it will be appreciated that any air gaps or leaks in the apparatus be sources of air intake rather than output, thereby substantially preventing unfiltered air egressing from the apparatus.

In another aspect of the invention, the guide means may be fitted with barrier means comprising, for example, a non-return gate or back draft damper to substantially prevent gas, vapours and fragments from passing from the apparatus back into the environment. The guide means may also be fitted with entry brushes. The entry brushes provide an additional safety precaution to the barrier means, and serve to prevent broken pieces of glass and other materials from being ejected from the guide means. This is particularly important when the crushing apparatus is fed manually with waste matter. The brushes may also serve to limit the rate at which waste matter is introduced into the crushing apparatus.

In use, the crushing apparatus of this invention crushes waste matter such as fluorescent tubes and light bulbs, and the crushed waste becomes deposited in the receiving means. Water may be present in the receiving means in an amount such that chemical reactions, for example the reaction between sodium and water, are quenched. Water may also be sprayed within the crushing apparatus in order to initiate chemical reactions which may then be quenched safely within the apparatus. The water or fluid filtration means may include ion-exchange filters in order to trap pollutants in an environmentally-acceptable form for disposal. Said filters may be removably mounted to facilitate replacement.

The receiving means may be removably mounted in the apparatus, door means being provided to provide access. In this way waste material may be removed for dumping, further processing, storage or transportation. The receiving means may be mounted on wheel means, preferably running in grooves in the apparatus. The grooves may extend along the inside of said door means, the door means being hinged at a floor level, such that on opening the door means, it acts as a platform or ramp on which the receiving means is securely guided as it is removed from the apparatus. The crushing apparatus of this invention may be constructed typically of heavy duty stainless steel. The crushing members may also be formed of stainless steel. The brushes in the guide means may usually be made of nylon.

It will be appreciated that the crushing apparatus of this invention is not restricted to the crushing of lamps, cathode ray tubes and fluorescent tubes. Other waste material, for example vegetable matter for composting, may also be crushed using the apparatus of this invention. The crushing apparatus may be operated to provide batchwise or continuous crushing of waste material. The apparatus may be sited in a permanent location or may be transported on a suitably adapted vehicle.

The present invention provides a safe and efficient means for crushing waste matter in which crushing takes place between the crushing members. Environmentally unacceptable vapours may be removed within the apparatus so that the quality of air returned to the atmosphere is acceptable. There is a reduced risk of downtime caused by blockage of waste between the crushing members and apparatus housing. Furthermore, waste matter need not be sorted by size or category before being introduced into the crushing apparatus. Following is a description by way of example only and with reference to the accompanying drawings of methods of carrying the invention into effect.

In the drawings:

Figure 1 is a perspective view of crushing apparatus of the present invention.

Figure 2 is a longitudinal cross section of the apparatus shown in Figure 1 along the line 1-1.

Figure 3 is a longitudinal cross section of part of crushing apparatus of this invention having guide means different from that shown in Figures 1 and 2.

Figure 4 is a perspective view of a crushing member used in this invention.

Figure 5 is a longitudinal cross section of an embodiment of the invention including a separator.

Figure 6 is a longitudinal cross section through an embodiment of the present invention wherein the crushing member spacing is adjustable.

Figure 7 is a detail of the separation rotor assembly of Figure 5 .

Electrical connections to the crushing apparatus are not shown.

Referring to the drawings, the crushing apparatus is shown generally at (10). The apparatus comprises a housing (11) having an upper surface (11a), rear wall (lib), first and second side walls (lie and lie), and an angled wall (lid). A guide means (20) is in the form of a chute, and is oriented at an angle of approximately 30° with respect to the upper surface of the apparatus. The guide means has an entrance port (25) . Disposed within the guide means are entry brushes (70) and a back draft damper (75), the latter disposed about a hinge (76). The brushes and damper serve to prevent vapours and debris from causing damage or injury by passing back out of the guide means.

The housing defines a chamber (30) in which two motor- driven crushing members (40) (motor not shown) are mounted on axles (not shown) substantially across the width of the chamber from the first side wall to the second side wall. Each crushing member has eight longitudinally-disposed radial vanes (41) disposed about a central axis (42). In another embodiment (see Figure 6) there are four such vanes for each crushing member, while in yet a further embodiment (see Figure 4) six such vanes are provided. The crushing members are adapted to contra-rotate one with another. The distance between the central axes (42) is adjustable; a preferred inter-axis distance is set in which the crushing members rotate in such a way that the vanes of one crushing member pass substantially between adjacent vanes of the other crushing member and vice versa.

An air filtration means (50) is connected with the chamber and includes a low-efficiency filtration screen (51) and three filters (52a, 52b and 52c). Filter (52a) is a medium-efficiency filter; filter (52b) is a high- efficiency filter and filter (52c) is an ultra high- efficiency filter. The air filtration means is positioned between the chamber and an air flow generating means (60) arranged to draw out from the interior of the housing (11) and through the filter means (50). Integral with the air flow generating means is an air vent (65) connected to ventilation ducts (not shown) which extend to the atmosphere.

A receiving container (80) for receipt of crushed waste is sited immediately below the chamber. The receiving container is mounted on rollers (81), and is filled with water up to a level (90). The water is pumped continuously into the receiving means in the direction of arrow W and out of the receiving means in the direction of arrow X by a pump (not shown) and through water filters (not shown) . Disposed within the receiving container is a fine mesh wire basket (85), having grip handles (86) for manual removal of the basket.

The housing (11) is provided with a door (100) hinged at (101) along its bottom edge, which door, in the closed position is disposed in a substantially vertical position when the machine is crushing waste. The door is opened to a substantially horizontal position when the receiving means is removed from the apparatus.

An alternative arrangement is shown in Figure 3 in which a guide means (21) has an entrance port (26) and entry brushes (71). The guide means (21) is oriented such that its longitudinal axis (L) is substantially perpendicular to the upper surface of the apparatus housing; this arrangement serves to direct waste matter more precisely towards the nip (43) between the crushing members.

An alternative crushing member (45) has six radial vanes (46) disposed longitudinally about a central axis (47).

In figure 5 an embodiment of the invention including a separator (200) is shown. The separator is made up of two rows of rotors (201) . The rows are substantially parallel and may lie along a line 40-70° typically 54.5° from the horizontal. The rotors each have four longitudinal radially extending vanes each of which rotors is arranged to intermesh with each neighbouring rotor of the adjacent row. The top row preferably rotates clockwise to draw downhill moving glass fragments and the like into the intermesh, and the bottom row rotates anti-clockwise. The glass fragments are crushed by the intermesh, and are deposited (240) in a fine mesh glass receptacle (80a). The lamp end caps are too large to be drawn into the mesh, and roll or bounce down the incline along the top row to be deposited (241) in a coarse mesh metal receptacle (80b). A door (230) may be opened to access the receptacle (80), which receptacle is provided with wheels (250) to allow the receptacle to be extracted for emptying. The use of a mesh as receptacles 80a and 80b allows the water or fluid to remain in situ during the emptying process.

In Figure 6, each of crushing members (40a,40b) is provided with chain wheels (264 and 263 respectively). A drive sprocket (261) provides the motive force for a chain (280) which rotates in a clockwise direction. A fixed idler acts as the pivot around which the chain is looped before contacting a top side of the chainwheel (263). The chainwheel (264) and a movable idler (266) are rotatably mounted at opposite ends of a swinging arm (270), which arm is pivotably mounted (265). The chain extends along a lower surface of the chainwheel (264) thereby to cause contra-rotation of crushing member (40a) with respect to crushing member (40b).

Should it become necessary to alter the rotor spacing, pivoting of the swinging arm (265) will move the chainwheel (264) and crushing member (40a). Chain tension is maintained by the opposite motion of movable idler (266).

In use, the crushing apparatus receives waste matter via the entrance port. The waste matter slides down the guide means and is broken up and crushed between the contra-rotating crushing members. The crushing members are oriented one with another so as to draw waste matter towards the nip between the members, thus ensuring efficient and thorough crushing. Crushed waste and environmentally unacceptable vapours pass into the scrubbing chamber.

Crushed waste leaves the crushing members and falls through the chamber into the wire mesh basket. The crushed waste in the basket is washed by a continuous flow of water into and out of the receiving means and through water filters. The water also serves to quench chemical reactions such as the reaction between sodium and water .

The air flow generating means serves to displace an air stream from the environment into the apparatus, through the crushing members into the chamber, through the filtering screen and filters, and into the atmosphere via the ducts. Environmentally unacceptable vapours and debris carried in the air stream are removed from the air stream by the screen and/or filters. The screen and/or filters are either cleaned in situ or replaced as appropriate, for example after a certain number of hours of service in the apparatus.

When a crushing operation is complete, or when the basket is full of crushed waste, crushing is interrupted, and the door is opened down to a substantially horizontal position, the receiving means is rolled away from the apparatus, and the crushed waste is removed from the receiving means by removing the wire mesh basket. The water is pumped around a closed system and pumping continues when the receiving means is removed from the apparatus.

Crushed waste, such as lamps, cathode ray tubes and fluorescent tubes, typically occupies only a small percentage of its original volume. The crushed waste is disposed of in an appropriate manner.

Claims

1. Crushing apparatus for environmentally unacceptable crushable waste, which apparatus comprises:

(i) guide means adapted to receive waste for crushing,

(iii) receiving means for receipt of crushed waste,

characterised in that said crushing means comprises at least two rotatable crushing members, the arrangement being such that the guide means serves to introduce waste to be crushed substantially between the members whereby the said members coact one with another to effect crushing of the waste.

2. Apparatus as claimed in claim 1 characterised in that the axis of rotation of each crushing member is skew one with respect of another.

3. Apparatus as claimed in claim 1 or claim 2 characterised in that separator means are provided between said crushing means and said receiving means. which separator means are adapted to at least partially separate different types of crushed waste.

4. Apparatus as claimed in any preceding claim characterised in that the guide means comprise at least one entrance port oriented in a plane above the crushing means, the arrangement being such that waste matter falls or slides down the guide means under gravity towards the crushing members.

5. Apparatus as claimed in any one of claims 1 to 4 characterised in that each crushing member is in the form of a drum or a rotor, adapted to receive waste material substantially perpendicular to a longitudinal axis of said crushing member.

6. Apparatus as claimed in claim 5 characterised in that each crushing member has a longitudinal axis about which there are provided a plurality of longitudinally-disposed radial vanes.

7. Apparatus as claimed in claim 6 characterised in that vanes of adjacent crushing members are adapted to intermesh.

8. Apparatus as claimed in any preceding claim wherein the spacing of adjacent crushing members is adjustable.

9. Apparatus as claimed in claim any preceding claim characterised in that said crushing means comprises two rotatable crushing members, which members are adapted to contra- rotate with respect to each other.

10. Apparatus as claimed in any preceding claim characterised in that the crushing means comprise a first row of at least two crushing members and a second row of crushing members , said members being arranged to receive waste material in series, the arrangement being such that the spacing between the members of the first row is greater than the spacing between the members of the second row.

11. Apparatus as claimed in any preceding claim characterised in that the receiving means comprise at least one receptacle adapted to receive crushed waste.

12. Apparatus as claimed in claim 11 characterised in that the receptacle is a skip, hopper, bucket or other container.

13. Apparatus as claimed in any preceding claim characterised in that the receiving means includes water or other fluid.

14. Apparatus as claimed in claim 13 characterised in that pump means are provided to circulate said water or other fluid through fluid filtration means.

15. Apparatus as claimed in claim 14 characterised in that said fluid filtration means comprises at least one filter removably mounted in the water stream.

16. Apparatus as claimed in claim 15 characterised in that said at least one filter is adapted for one or more of particulate filtration, ion exchange, chemical reaction, absorption.

17. Apparatus as claimed in any preceding claim characterised in that at least one mesh wire basket is removably suspended in the receiving means.

18. Apparatus as claimed in any preceding claim characterised in that first and second wire baskets are removably suspended in said receiving means, wherein said first basket is mainly for receiving glass waste, and said second is mainly for receiving metal waste.

19. Apparatus as claimed in any one of claims 3 to 18 characterised in that the separator means is a separator adapted to sort the waste according to size, or according to material characteristics, or both.

20. Apparatus as claimed in claim 19 characterised in that said separator comprises a first row of two or more mini-rotors and a second row of at least one mini-rotor, which second row underlies said first row, and wherein the spacing between adjacent mini-rotors is such that lamp endcaps are unable to pass therethrough.

21. Apparatus as claimed in claim 20 characterised in that the mini-rotors are provided with longitudinal vanes, the arrangement being such that the mini rotors of the second row intermesh the mini-rotors of the first row and wherein the first row mini-rotors rotate in a fist direction, and the second row mini-rotors rotate in a second direction.

22. Apparatus as claimed in either of claims 20 and 21 characterised in that said first row and second row are mounted at an angle from the horizontal, the angle being such as to induce said end caps to travel downhill along said top surface towards metal receiving means.

23. Apparatus as claimed in any preceding claim characterised in that said apparatus includes an exterior housing.

24. Apparatus as claimed in claim 23 characterised in that said housing encloses or communicates with air filter means for removing airborne waste particles and contaminants from the apparatus.

25. Apparatus as claimed in claim 24 characterised in that said air filter means includes at least one of; particulate filter means, vapour filter means, and gas filter means.

26. Apparatus as claimed in either of claims 24 or 25 characterised in that said air filter means includes air flow generating means adapted to; draw air into the apparatus, over the crushing means, through the air filter means and thence to the exterior of the apparatus.