GB2343472A - Apparatus and method for recycling materials - Google Patents

Abstract

An apparatus is for recycling construction materials, particularly road material. It consists of a compact portable crusher that has a hood 15 and wheels 14. The crusher is in the form of a plate 2 that has teeth 3 that crush material against a fixed crushing plate 1. The plate is connected to an attachment 4 and is moved by a piston acting along line A-B. A grid is used to ensure that only material of a requisite size is obtained. Large uncrushed material is recycled to be crushed again. Dust emission is suppressed by a water spray system.

Description

APPARATS AND METHOD FOR RECYCLING GROUND MATERIAL The present invention relates to an apparatus and a method for recycling construction material, a kit of parts forming the apparatus and a use of the apparatus.

The invention relates particularly to road repair but has applications for use on building sites in general, for gardens and drives and in all situations where an apparatus for recycling construction material in situ is of value.

Research has shown that the poor condition of British roads is mainly due not to poor construction but to the standard of repairs carried out on them. The Highways and Utilities Commiffee issued a code of practice in 1992 aimed at improving the quality of highway repairs entitled"The Specification for The Reinstatement Of Openings in Highways". This is gradually improving the standard of repairs but a key requirement of the specification is that the excavated material cannot be automatically recycled, as happened formerly. In practice, repair undertakers arrange for the excavated spoil to be removed from site and be replaced with"first use"quarried, crushed and graded stone.

A report by Humphries and Partners [1995] estimated that 77 million tonnes of construction waste are generated annually in the UK, of which only 4% are recycled to produce secondary aggregate.

On large projects the excavated material can be taken to a crushing plant, but there is a shortage of such sites in the UK.

Smaller scale crushers have not been available to date. There is also a general prejudice amongst designers in the area that it is not possible to construct a compact crusher with sufficient strength to crush construction material.

The Halcrow Fox Report (1994) estimates the total number of highway openings to be in the range of 2. 4 to 4 million annually and British Gas Research found that around 70% of repairs to highways involve a surface area of less than 2 square meters, and hence a volume of less than 2. 5 cub. metres of material, of which only an average of 20% to 30% needs to be reduced, which makes the use of the crushing plant facility impracticable. The excavated material is usually disposed of by tipping.

This problem is mirrored on building site and in garden and drive alterations and repair, where disposal of excavated or other waste material from demolished structures or natural features is difficult. The material is often somewhat bulky and/or awkwardly shaped and must be removed to a waste site.

It is therefore an object of the invention to provide an apparatus and a method which overcomes the above problems.

According to a first aspect of the present invention there is provided an apparatus for recycling construction material comprising a compact processor having means to process construction material, and being driveable by drive means.

Processing may be any operation which it is desired to perform on construction material and is suitably crushing or otherwise degrading in size or upgrading in quality. Crushing may include any other processing for transformation into useful construction materials for example grading, blending, mixing, casting, compacting, segregating or the like.

For highway recycling, the output crushed material must conform to one of the size distributions specified in the Code of Practice for Roads and Bridges, and ideally should be that of the defined Type 1 grading. It has been found, surprisingly that a crusher to produce such a grade of material in a single operation can be designed. In another embodiment of the invention, secondary screening of the crusher output material may be employed to achieve a specific grading, where oversize material be again passed through the crushing cycle.

The apparatus may have an inlet means for large grade particulate material or objects and an outlet for a low grade crushed particulate material. Material may be tipped, conveyed, shovelled or otherwise into and out of the apparatus. Alternatively the apparatus is in the form of a jaw which may be brought into position about material to be crushed and reduces the material without the need for transporting to or from the apparatus. The jaw may comprise a collection area if it is desired to collect crushed material, for example includes a scoop which forms a collection area in use.

Surprisingly, we have found that it is possible to provide a compact crusher, which is suitable for use in situ. The invention allows the private or commercial user or builder to crush construction material for high quality and environmentally friendly refilling of excavated sites and/or demolition and easy disposal of waste.

In its use for highway repair the invention offers substantial environmental benefits by increasing the quality or repair, reducing the need to dispose of waste at a waste site, elimination of the need for quarried material, improved productivity of the repair team and a reduction in the overall time of disruption for the highway user.

It enables site/soil remediation to achieve the same standards of reinstatement as obtained with graded stone, eliminates the need to remove the whole of the excavated material from site for land fill, enables a one stop reinstatement service and reduces the elapsed time of effecting the re-instatement Reference herein to construction material is to any demolished or excavated materials, typically from excavation, demolition or degrading of roads and pavements, runways, sport and recreation areas, bridges, tunnels, quarries, mines, natural rock or hard core such as in sites for pipe laying or development, buildings, walls, chimneys or other waste material from industrial sites, such as damaged furnace bricks and tiles, casting moulds, failed concrete or refractory cast objects, etc for degrading. The construction material may be any particulate material or objects and may be any aggregate or mix of construction materials as hereinbefore defined. Construction material includes waste, particularly building material waste such as paving slabs, pillars, beams, tarmac and the like, (reinforced) concrete, brick, gravel, stones and rock, ceramics and refractory materials or a mix of construction material and reinforcing material such as steel or iron ties or cables or aluminium frames, packing or other incidental material such as polystyrene foams, timber, glass or carbon fibre, glass, plastics, soil, earth, sludge, loam, clay, sod or any other material.

Reference herein to compact is to an apparatus that is compact in comparison to standard highway repair equipment. Preferably the apparatus is portable, ie is capable of being transported to a construction location for example by trailer, pick up truck, lorry or van, or of being attached to a boom, arm or cable of a construction apparatus such as a digger, crane, pick up or the like and be appropriately moved and positioned. Apparatus may be kept on site for the duration of a construction job and may be stationary or moved around the site or may be moved from site to site.

Any construction of the apparatus as hereinbefore defined may be envisaged which falls under the above definition of compact. Preferably, the device is portable and more preferably has a footprint of less than 2 m2 More preferably, the footprint is of less than 1 m2. Ideally, the apparatus is the same size as a cement mixer or smaller and has a footprint of approximately 0. 5 m2 for industrial or private use.

Reference herein to crushing is to reduction in size of particulate material or objects by means of pressure exerted on the material, usually suitable crushing means having a cyclical relative movement.

The apparatus of the present invention may comprise any suitable crushing means, such as crushing plates, wheels or the like. Preferably it comprises a pair of crushing plates adapted for relative movement for crushing by puncturing, splitting and crushing and facilitating movement into, through and out of the crushing zone.

Either or both plates may be adapted for movement. Preferably, one of the crushing plates is adapted for movement towards the other, providing a fixed and a mobile crushing plate.

The crushing plates may be of any suitable shape and orientation. Preferably in a mobile apparatus having an inlet and an outlet, the plates form two side walls of an open ended passage. The inlet and outlet are suitable disposed relative to each other to enable passage of material therebetween, and preferably form a substantially funnel shaped cavity or hopper. Construction material may then be fed into the wider inlet end and can exit at the narrower outlet end when crushed.

Preferably, the funnel is substantially vertical in use and the mobile plate forms a jaw with the fixed plate within the passage and moves on a pivot or cam to expand and contract the funnel during the crushing movement, thereby facilitating movement by gravity through the crushing zone towards the outlet. The apparatus may comprise a grid at its outlet end through which sufficiently crushed construction material exits the apparatus. The grid may retain large grade particulate matter which may be removed periodically or continuously or may be further crushed by additional crushing means proximal to the grid. The apparatus may comprise means for recycling construction material which does not pass through the grid through to crushing means.

Thus, oversize material is passed again through the crushing cycle.

The grid is suitably any form of mesh, ribs and the like which serves to grade material. The grid may be adjustable, for example ribs may be removable or may be inserted into slots to create a desired grid size. Alternatively the grid may be interchangeable and different grade grids may be provided for a desired use. The grid is preferably accessible to remove blockage or debris such as iron and steel reinforcing which breaks away from particulate material during crushing. The apparatus suitably operates at a relatively slow frequency and blockage leads to overpressure and automatic disabling enabling blockage removal. Preferably the drive means is interlocked to disable on build up of pressure and/or on access to the grid and automatically restart on removal of over pressure or replacing means to access the grid.

The machine may optionally include a mechanism for clearing the grid from blockage by jammed crushed material. This could be in the form of bars which are attached to one of the crushing plates such that on the opening cycle, the bars are forced up through the grid or mesh, displacing any blocked material back into the crushing zone.

Any shape of crushing plate may be envisaged to produce the open ended passage, for example either plate may be substantially planar, concave or convex.

Preferably, one plate is convex in shape and the other is substantially planar. Ideally, the mobile plate is convex, by use of curved or bent material. The fixed plate is preferably formed in a single substantially planar section. It is preferably at an angle of between 15 and 5 degrees, more preferably 10 degrees to the vertical in use, whilst the angle of the mobile plate to the (vertical) fixed plate varies in use.

Alternatively the crushing plates in a mobile apparatus are of any shape and orientation suitable for forming a jaw. Preferably the plates are shaped to facilitate positioning about an object or pile of material to be crushed and to retain the object or material in the crushing zone or draw into the crushing zone during processing.

Processed material then remains in a pile which may be transported or distributed as desired for use.

The mobile plate may additionally comprise a strengthening member at its non-active surface. The crushing plates may be fixed permanently to the apparatus or exchangeable. Preferably the plates are exchangeable to allow different jaws to be fitted for different applications and to allow for replacement of worn or damaged plates.

The apparatus may be provided with any suitable drive arrangement for the crushing plates as hereinbefore defined, for example a piston or a stepper motor and rod. Suitably, at least one piston drives the plate or plates and has a head which is attached pivotally to the plate to be driven. Additionally or alternatively a cam and follower arrangement may be provided for directed plate movement.

Either or both plates may comprise surface features on their active surfaces for enhanced crushing or gripping of construction material. For example, grooves, teeth or other projections, or surface roughness may be provided. Preferably only the mobile crushing plate comprises teeth.

The apparatus of the present invention may be provided with any suitable feature which enables reduction in size to form a compact crusher of sufficient strength to be constructed. Thus use of modem materials, improved design parameters and a flexible control system may all contribute to its functioning.

The apparatus may be provide with means to suppress dust emission such as a water spray system. Such a spray system may be designed to be operated automatically by the jaw or other movement, or may be independently supplied. Water may also be added to ensure the water content of the crusher material produced contains sufficient water to meet the requirements of the Code of Practice for Highways.

In one preferred embodiment the apparatus comprises means to step up the power of the drive system, preferably by means of a feature of the crushing plates, for example increased leverage in its crushing jaws to increase its crushing power. The attachment of the lower end of the mobile plate acts as the fulcrum in a lever. The piston or other drive provides a force to crush material in a crushing zone of the funnel.

Preferably, the piston as hereinbefore defined has an increased length of stroke relative to its jaw size over conventional crushers. This stroke may be of the same order of magnitude as the plate length and is preferably longer than the length of movement caused by the stroke of the parts of the mobile plate which act to crush the construction material. More preferably the stroke is more than 1. 5 times, ideally more than twice this length.

This may be achieved by mounting the piston head towards the open end of the funnel. Alternatively, a more complicated arrangement of leverage may be envisaged. Preferably, the piston head is mounted at least two thirds, more preferably three quarters of the distance between the closed and open funnel ends. Ideally, the piston head is mounted in a position, which is spaced from the crushing zone of the funnel towards the open end of the funnel.

The apparatus may be powered by any convenient source, such as a manually operated hydraulic pressure pack, mains electricity, or building site generator.

In one preferred embodiment it comprises a socket or a cable suitable for attachment to a mains supply. Additionally or alternatively, the apparatus may comprise a portable power pack.

The apparatus of the present invention is designed to be lightweight and is preferably of not more than 150kg in weight ; more preferably it weighs 50-100 kg.

Any suitable hydraulic or pneumatic pressure source may be used for the apparatus. However, advantageously it may be powered by a conventional hydraulic pressure source of less than 200 bar. More preferably the source may be 100-150 bar, or ideally 100-120 bar. The hydraulic pressure source may be in the range 80 to 150 bar, preferably 90 to 120 bar, most preferably about 100 bar. Power packs universally available commercially operate at 100 bar. Any suitable fixed or mobile guard means may be provided for the apparatus as hereinbefore defined. Preferably a solid or mesh lid is provided which may be provided with means to interlock with the drive means to disable the apparatus with the jaws in an open position when the lid is open.

Any suitable control means may be provided for operation of the apparatus.

Preferably, the apparatus can be selectively manually operated, with manual control of speed of crushing. This helps to prevent overloading of the apparatus. Manual operation may be hand or foot controlled. Foot control increases safety and convenience leaving both hands free for a single operator to feed material etc. A foot control may open the swivel guard automatically disabling the drive, and allowing feed of material, then release of the foot control closes the guard and the crushing automatically recommences.

Additionally or alternatively, a feedback system may be provided for detection of excess pressure in the apparatus and allow retraction of the mobile jaw for manual remedy.

The present invention also relates to a method of recycling construction material in situ by use of an apparatus as hereinbefore defined. Suitably material is introduced, crushed and removed or the apparatus is located about material to be crushed, activated and removed.

The present invention also relates to a method for construction comprising excavating construction material as hereinbefore defined, crushing and reinstating or reusing for construction.

The methods may be used to process material from and to any desired grade or form. The invention is now illustrated in non-limiting manner with reference to figures 1-6.

Figure 1 is a sketch diagram of the apparatus of the present invention showing three positions of the crushing jaws. Mobile crushing plate (2) rotates about pivot B at the piston head due to movement of a piston (not shown). The distance AB represents the most extended position of the piston. The mobile crushing plate is attached at its lower end by attachment means (4) for movement as shown in the figure.

The fixed crushing plate (1) has no surface features, whereas mobile crushing plate (2) is provided with teeth (3). The figure shows crushing zone (6) which extends where teeth are present on mobile plate (2). The main crushing zone is towards the lower end of the funnel. The crushed material passes through a grid (5). In this way, the crushed material is sized. Crushed material which is too large to pass through the grid is recycled into the crushing zone. Although a number of schemes could be envisaged in order to perform the recycling, recyling can actually be achieved by the mobile plate (2)-when the jaw opens, the movement of the mobile plate (2) acts to throw crushed material which has not passed through the grid (5) back into the crushing zone.

Figure 2 is a simplified diagram of the jaws shown in Figure 1.

Figure 3 is a plan view of a grid (7) having a mesh (8) comprising ribs (9) suited to size crushed material.

Figure 4 is an elevation of an apparatus (10) showing having exterior shaped according to the funnel crushing zone, and having swivel guard (11) interlocked to the power source or drive means and having a guard (12) enclosing a hydraulic ram (13). The apparatus is mobile and has wheels (14).

Figure 5 shows (a) front and (b) side views of apparatus of the present invention. Figure 6 shows (a) plan and (b) perspective views of the appartus of Figure 5. The apparatus of Figures 5 and 6 is substantially similar to the apparatus of Figures 1 to 4, and thus like numerals are used to denote like structural features. The apparatus has a hood (15). The hydraulic ram (13) can be driven by a separate power pack or attached to the hydraulic system of a digging machine.

Further advantages and features of the invention are apparent from the foregoing.

The accompanying Table shows the size distribution of the outputted material achieved with a device of the present invention. The material thus graded falls within the Type 1 grading definition, and is thus suitably sized for use in construction of, for example, motorways.

SIEVE MASS MASS PERCENTAGE SIZE RETAINED PASSING PASSING mm kg kg % 37. 5 mm 265 1735 88.75 20. 0 mrn 421 1314 66. 7 10. 0 mm41589944. 95 5. 0mm 301 598 29. 9 2. 36 mm 208 390 19. 5 1. 18 mm 124 266 13. 3 600 mic. 98 168 8.4 300 mic. 91 77 3.85 150 mic. 35 42 2.1 pan 42 0 0 Total 2000

Claims (21)

1. CLAIMS 1. Apparatus for recycling construction material comprising a compact processor having means to process construction material, and being driveable by drive means.
2. 2. Apparatus according to claim 1 having a footprint of less than 2 m2, preferably less than 1 m2, most preferably about 0. 5 m2.
3. 3. Apparatus according to claim 1 or claim 2 comprising crushing means.
4. 4. Apparatus according to claim 3 in which the crushing means comprises a pair of crushing plates adapted for relative movement thereof.
5. 5. Apparatus according to claim 4 in which one of the crushing plates is fixed and the other crushing plate is adapted for movement towards the fixed plate.
6. 6. Apparatus according to claim 4 or claim 5 in which the crushing plates form a substantially funnel shaped cavity through which construction material is fed.
7. 7. Apparatus according to claim 6 in which the substantially funnel shaped cavity is substantially vertical in use.
8. 8. Apparatus according to any previous claims comprising a grid through which crushed construction material of suitable predetermined sizes can pass.
9. 9. Apparatus according to claim 8 comprising means for recycling construction material which does not pass through the grid through the crushing means.
10. 10. Apparatus according to claim 8 or claim 9 comprising a mechanism for clearing the grid from blockage by jammed construction material.
11. 11. Apparatus according to any previous claims in which the drive means comprises at least one piston.
12. 12. Apparatus according to any of claims 1 to 10 in which the drive means comprises a stepper motor and rod.
13. 13. Apparatus according to any previous claims comprising means to suppress dust emission.
14. 14. Apparatus according to claim 13 in which the means to suppress dust emission is a water spray system.
15. 15. Apparatus according to any previous claims powered by a hydraulic pressure source.
16. 16. Apparatus according to claim 15 in which the hydraulic pressure source is a conventional hydraulic pressure source of less than 200 bar.
17. 17. Apparatus according to claim 16 in which the hydraulic pressure source is less than 150 bar, preferably less than 120 bar.
18. 18. Apparatus according to claim 16 or claim 17 in which the hydraulic pressure source is in the range 100 to 150 bar, preferably 100-120 bar.
19. 19. Apparatus according to any of claims 16 to 18 in which the hydraulic pressure source is in the range 80 to 150 bar, preferably 90 to 120 bar, most preferably about 100 bar.
20. 20. A method of recycling construction material in situ by use of an apparatus according to any of claims 1 to 19.
21. 21. A method for construction comprising excavating construction material recycling said construction material in a method according to claim 20, and reinstating or reusing the recycled material for construction.