Conveyor belt cleaning arrangement

Abstract: The present invention provides an arrangement for cleaning conveyor belts. The invention includes an elongate beam (1) mounted so as to extend substantially transversely below a return run of a conveyor belt (2), the beam (1) mounting scraper means (7, 8) such as to be in contact with the underside of the conveyor belt (2). Spray means (4) are also provided and are connected to a source of liquid (4a), the spray means (4) being adapted to apply a spray of said liquid across the underside surface of the conveyor belt (2), adjacent to, and immediately before or substantially simultaneously with, contact between the conveyor belt (2) and the scraper means (7, 8).

Description: This invention relates to a conveyor belt cleaning arrangement and more particularly to a conveyor belt cleaning arrangement for more effectively removing residues attached or adhered to the return run of a conveyor belt. Up until this time various arrangements have been known for removing residues from conveyor belts, including for example scrapers mounted in such a way as to be held in contact with the moving surface of a conveyor belt, the scrapers being used to remove residues from the belt. Such an arrangement for cleaning conveyor belts is known from Australian patent specification No 449,142. While such arrangements have met with some amount of commercial success, they have not been as successful as might have been expected, given that there has been a limitation to the amount of matter that can be removed from the belt. In particular, the scrapers have not always been effective since they do not always faithfully follow the contours of the belt. Furthermore, such scrapers alone are not always effective for all cleaning requirements. For example, a sticky substance adhered to the belt is generally unable to be removed from the belt by a scraper alone or if it is removed, then it often adheres to the scraper, thus reducing the efficiency of the scraper. Further, it has been found that the build-up of residues and molds on conveyor belts is indicative of the disadvantages of relying on scraping means alone to clean conveyor belts. It has also been found that many particles of substances adhering to or being built-up on the surface of a conveyor belt, are of a profile sufficiently flat to pass under a scraper without being dislodged from the belt. This problem has been aggravated by the fact that with flat, compressed particles, there may well be no space for a layer of air between the belt and particle, as a consequence of which flat particles are often held tightly on conveyor belts by air pressure or suction. Moreover, conveyor belt cleaning arrangements are known which are provided with spray- and scraper means so as to clean the belt surface more effectively, see e.g. DE-B-1227384. However, the spray means are generally remotely arranged from the scrapers and thus from the belt surface. It is an object of the present invention to ocercome or at least minimize the above disadvantages. It is a further object of this invention to provide a straight-forward and efficient arrangement for cleaning conveyor belts. Other objects of this invention will become apparent from the following description. According to one aspect of this invention there is provided an arrangement for cleaning a conveyor belt comprising scraper means and spray nozzles as defined in detail in independent claim 1. Other aspects of the invention will be apparent from the dependent claims. A preferred embodiment of the present invention will now be described by way of example only and with reference to the accompanying drawings, wherein: Fig. 1 is a side elevation of a conveyor belt cleaning arrangement according to the present invention; Fig. 2 is a corresponding front elevation; Fig. 3 is an isometric view; Fig. 4 shows a front elevation of an elongate, hollow beam and associated fittings; and Fig. 5 is a fragmentary side elevation of a conveyor belt; an end-roller; and an inventive cleaning device. The present invention provides an arrangement for the cleaning of conveyor belts and in particular for applying a cleaning action to the underside of the return run of a conveyor belt. As referred to hereinbefore, it has been known to apply scraper means to the underside of conveyor belts to attempt to clean same and remove extraneous matter therefrom. However, this has not always been as successful as might have been expected. The present invention provides for a combination of scraper means and spray means, the spray means being connected to a source of liquid, so that a spray of liquid is applied to the underside of the conveyor belt at a position that is preferably immediately before or substantially simultaneous with the contact between the scraper means and the underside surface of the conveyor belt. It has been found that the application of a spray of liquid to the underside of the conveyor belt, at a position immediately before or substantially simultaneous with the application of the scraper means to the belt, greatly assists in removing extraneous matter from the belt, which matter was not removed up until this time by the application of scraper means alone. In the preferred form of the invention as shown in the accompanying drawings, it will be seen with particular reference to Figs 1 and 2 that an elongate hollow beam 1 is mounted below the underside of the conveyor belt 2 so as to extend transversely below the return of the conveyor belt 2, relative to the longitudinal axis and direction of travel and direction of travel of the belt 2. The beam 1 is preferably supported by support arms or struts 3. Other appropriate mounting or support means can however be used. In the preferred form of the invention the beam 1 is provided with one or more scraper means, generally indicated at 5, the scraper means 5 being mounted or fixed to the beam 1, for scraping residues adhered to the underside surface of the conveyor belt 2. The scraping means 5 include a resilient member 6 which may be of an elastomeric material, such as for example natural or synthetic rubber, polyurethane, synthetic resin or the like; a scraper member 7 formed of an appropriate material and having for example a tip 8 of hard material such as tool steel, stainless steel, tungsten carbide, ceramic polyurethane or the like is provided at the upper end thereof. In one preferred form of the invention a deflector plate 9 is mounted to the resilient member 6 and has at its upper end thereof a scraper member 7 affixed thereto by appropriate attachment means. The scraping tips are, in one form of the invention, detachable from the scraper members 7 so that they may be replaced when worn or damaged. In a preferred form of the invention a plurality of scraper means 5 are mounted in spaced apart relationship along the length of the beam 1 (and generally transverse to the longitudinal axis and direction of travel of the belt 2) by means of appropriate mounting means, generally indicated at 10, so that the tips 8 are in pressure contact with the underside surface of the return run 2 of a conveyor belt. Thus, on movement of the conveyor belt, the tips 8 follow the undulations and various contours of the belt and apply a scraping action thereto, by virtue of the elastic deformation of the resilient member 6. As is best seen in Fig. 1 of the accompanying drawings, mounting means 10 comprises a mounting plate 11 fastened to the resilient member 6 by a plurality of connection assemblies such as for example nut and bolt assemblies 12 by way of a cladding plate 12A. The belt 2 of the conveyor of the present invention is formed of any appropriate material and for example extends about a plurality of spaced apart rollers or pulleys 17. Preferably the rollers or pulleys 17 are spaced apart one from the other and one or more thereof is or are connected to a source of power or prime mover, such that on actuation thereof the belt 2 is caused to move and rotate about the rollers or pulleys 17; preferably substantially horizontally. In use the cleaning arrangement of the present invention is provided below the underside of the return run of such a conveyor, such that on actuation and movement of the conveyor it will move over and relative to the cleaning arrangement of the present invention. In a preferred form of the invention as shown in the accompanying drawings, a plate 9 may extend downwardly past nozzles 4 (to be described hereinafter) and beam 1; the plate 9 is preferably provided with a plurality of apertures such as 9A positioned and dimensioned so as to receive therethrough nozzles 4 associated with the spray means, as will also be described hereinafter. The location of the nozzles 4 through the apertures 9A will not restrict the spray of cleaning liquid onto the belt, but the plate 9 will deflect falling residues and liquid from the belt, thus preventing or minimizing a build-up of debris and associated matter on the beam 1. In one form of the present invention, the portion of the plate 9 below the spray nozzles 4 may be formed as a separate plate, such as to assist in the maintenance and cleaning of the arrangement. In the preferred form of the invention shown by way of example only in the accompanying drawings, a plurality of scraping means 7 mounted to deflector plates 9 can be mounted to the beam 1 in a substantially side-by-side; spaced apart and juxtaposed relationship, extending transversely across the underside of the conveyor belt. If desired however, a single scraping means 7 can be mounted to the beam 1 and can extend across the underside of the conveyor belt, substantially transverse to the longitudinal axis or direction of travel of the conveyor belt. In the preferred form of the invention, the beam 1 is substantially hollow and constitutes a reservoir and conduit for cleaning liquid to be applied to the underside of the conveyor belt 2. Referring further to the accompanying drawings, the beam 1 preferably mounts appropriate spray means, preferably in the form of a plurality of nozzles 4 which are in communication with the interior reservoir 4A of the beam 1. In the preferred form of the present invention a plurality of laterally spaced apart nozzles 4 are provided along the length of the beam 1. The nozzles 4 (or other spray means) are preferably adjustable, so that the angle(s) thereof are adjustable. The nozzles 4 are positioned and attached to the beam 1 so as to be in communication with the reservoir 4A of the beam 1 and so as to be angled upwardly towards the underside of the belt 2. The nozzles 4 preferably extend along the length of the beam 1 so as to extend across the underside of the belt 2 in a direction substantially transverse to the longitudinal axis of the belt, and the direction of travel of the belt 2. In one preferred form of the invention and as shown in the accompanying drawings, a spray nozzle 4 is provided in association with each scraper means 7 and deflector plate 9, holes 9A being provided in the deflector plates 9 so that the nozzles 4 can pass therethrough. Referring to Fig. 4 of the accompanying drawings, the beam 1 is shown as being connected to a liquid supply means 13A, by means of a supply conduit 13. A flow control valve 14 is provided together with a sieve or strainer 15 and an end cap 16. In the preferred form of the invention the beam 1 is threaded (or formed in some other appropriate manner) at each end so that it is able to receive liquid from either end according to the layout of a plant. The strainer or sieve 15 is provided to minimize and prevent entry of extraneous matter into the reservoir 4A of the beam 1, from the liquid supply means. As will be appreciated, the entry of such extraneous matter would block and interfere with the spray means and in particular the spray nozzles 4. In use, and on the flow control valve 14 being turned on, liquid such as for example water or other appropriate cleaning liquid will pass from the supply conduit 13 through the sieve or strainer 15 and into the reservoir 4A. Thereafter the pressure of liquid will cause the liquid to pass through the nozzles 4 to be directed at the underside of the conveyor belt 2. The cleaning arrangement of the present arrangement is preferably located below the underside of the return run of a conveyor belt adjacent to but spaced apart from a position where the belt 2 leaves an end roller or pulley 17. This is shown by way of example only in Fig. 5 of the drawings. In use it has been found that in one form of the invention the spray means in the form of nozzles 4 should be angled relative to the underside of the conveyor belt 2, such that the spray of liquid is applied to the underside of the belt 2 at a position adjacent, immediately before or substantially simultaneous with the application of the cleaning tip 8 to the underside of the belt 2. It has been found that in this way, the combination of the cleaning liquid and scraper means maximises the benefit of the invention. In one form of the invention it has been found desirable to apply the spray of cleaning liquid at a position up to 200 mm after the belt 2 leaves the roller 17 and before the belt comes into contact with the scraper means of the present invention. Referring by way of example only to Fig. 5 of the accompanying drawings, it is in one form of the invention desirable to apply the spray of liquid at a position within 200 mm of the tangential position "X", where the belt 2 leaves the roller 17. In one form of the invention it is particularly advantageous to have the spray means, preferably in the form of the nozzles 4 angled at an angle approximately 45° relative to the longitudinal axis of the underside of the belt, the spray from such angled nozzles also being at an angle of substantially 45°, this resulting in a substantially "chisel" effect against the underside surface of the belt 2, which removes a substantial amount of residue from the underside of the belt, leaving a relatively small amount of fines in water suspension to be removed by the scraper means of the present invention. In a preferred form of the present invention it is desirable to have the width of the belt covered by a spray of the cleaning liquid and to this end where a plurality of spray nozzles 4 are provided along the length of the beam 1, the nozzles are so formed and provided, that the spray from each nozzle overlaps one with the other, such as to provide a complete coverage across the width of the belt. In one form of the invention, and by way of example only, there may be a 50 mm overlap of spray from each nozzle 4. While the spray means is described by way of example only, in the form of nozzles, it should be appreciated that other appropriate forms of spray means can be used. The liquid of the present invention can be any appropriate cleaning liquid such as for example water, water combined with one or more additives, a cleaning liquid, detergent or the like. The present invention recognises that while scraping means have been relatively effective in removing matter from the undersides of conveyor belts, they have not, of themselves, been appropriate for removing all matters. The present invention provides a cleaning arrangement which has the capacity to minimize these problems by substantially increasing the amount of matter that is capable of being removed from the underside of conveyor belts, essentially by combining the use of a spray of cleaning liquid with the use of scraper means. The spray of cleaning liquid preferably acts as a liquid chisel to remove bulk residue, and to assist in removing sticky materials and substances which have previously been located in grooves and cracks in the belt and over which a scraper means per se would pass. The provision of the liquid spray means substantially increases the efficiency of the cleaning arrangement of the present invention. Minute and flat particles which have previously been left on the conveyor belts, are now able to be effectively removed by the cleaning arrangement of the present invention. The use of the liquid spray also acts as a lubricant, increasing the life of the scraper tips of the present invention and reducing the wear on the conveyor belt. The lubricating action of the liquid spray also reduces friction and minimizes heat build-up. Further, the cleaning liquid is continuously washing away residues collected by the scraper so as to ensure that the cleaning arrangement does not become clogged. The deflector plates of the present invention assist in that regard. In the preferred form of the invention, the beam 1 which acts as a mounting beam for the scraper means also forms a reservoir for the cleaning liquid, cleaning nozzles preferably being mounted to the beam so that the spraying means and scraper means are formed in a substantially unitary construction which allows for effective mounting, utilisation, replacement and repair. It should be appreciated that the present invention provides substantial advantages over arrangements used up until this time. Further, modifications and improvements may be made to this invention without departing from the scope thereof as defined by the appended claims.

Claims: An arrangement for cleaning a conveyor belt (2), comprising an elongate beam (1) mounted transversely below an underside of a return run of said conveyor belt (2), a liquid reservoir (4a) being formed in said beam (1), the liquid reservoir (4a) being connectable to a supply (13) of liquid; a plurality of spray nozzles (4) being laterally spaced apart along the length of the beam (1), the spray nozzles (4) being in communication with the liquid reservoir (4a); scraper means (7, 8) being operatively attached to said beam (1) for contracting the underside of the belt (2); and a deflector plate (9) being provided and extending downwardly from said scraper means (7, 8), said deflector plate (9) being so formed that the spray nozzles (4) extend therethrough and spray issuing from said spray nozzles can pass onto the underside of said belt (2) adjacent to and immediately before, or substantially simultaneous with, contact between said belt (2) and said scraper means (7, 8). An arrangement as claimed in claim 1, wherein a plurality of scraper means (7, 8) are mounted to and extend along the length of said beam (1); at least one spray nozzle (4) being provided adjacent each scraper means (7, 8). An arrangement as claimed in claim 1 or 2, wherein angles of said nozzles (4) are adjustable. An arrangement as claimed in any of claims 1 to 3, wherein each nozzle (4) is so angled relative to the underside of said conveyor belt (2), that spray therefrom is at an angle of 45 relative to a longitudinal axis and direction of travel of said belt (2); the spray thereby applying a chisel-like action to extraneous matter on the underside of said belt (2). An arrangement as claimed in any preceding claim, wherein the nozzles (4) are so positioned and angled that spray therefrom overlaps to thereby provide a spray of liquid across the width of the underside of said belt (2). An arrangement as claimed in any of claims 1 to 3 or claim 5, wherein the spray means (4) applies a spray of liquid to the underside of said conveyor belt (2) at a position to 200 mm from a tangential point (x) at which said belt (2) leaves a roller (17).

Inventors: BARNES EDWIN ARTHUR, BARNES, EDWIN ARTHUR
Applicants: BELLE BANNE AUST PTY LTD, BELLE BANNE (AUST.) PTY LIMITED
Application year: 1990
Main classification: B65G45
IPC codes: B65G45