GB2548119A

GB2548119A - A dryer apparatus, associated methods, and a cleaning system

Info

Publication number: GB2548119A
Application number: GB1603992.7A
Authority: GB
Inventors: Haith David
Original assignee: Tickhill Engineering Co Ltd
Current assignee: Tickhill Engineering Co Ltd
Priority date: 2016-03-08
Filing date: 2016-03-08
Publication date: 2017-09-13
Anticipated expiration: 2036-03-08
Also published as: GB201603992D0; GB2548119B

Abstract

A dryer apparatus 1 suitable for drying one or more objects (vegetables), comprises an inlet 15 for receiving the object(s) to be dried, an outlet 16 for outputting the object(s) from the apparatus and a heated roller array 14 containing a plurality of heated rollers 141 located between the inlet and the outlet. A heater system may be in the form of heating elements within the rollers and heats the heated rollers. Each heated roller may be rotatable by a drive belt 13 to drive movement of the object(s) across the roller array from the inlet towards the outlet. The apparatus may comprise a drive belt tensioning system 137, belt cleaner 131a, an object clearing mechanism 17, and a cooling system 18.

Description

Title: A dryer apparatus, associated methods, and a cleaning system Description of Invention

Embodiments of the present invention relate to an apparatus for drying vegetables or other objects, along with associated methods of operating the apparatus, and cleaning systems including the apparatus.

After vegetables, such as root vegetables, are harvested they are typically cleaned prior to sale. This cleaning serves several purposes including removal of potential contaminants (e.g. bacteria from the soil), which may be harmful to someone eating the vegetables, and also for aesthetic reasons.

Damage to the vegetables can reduce their value and should, therefore, be avoided during the cleaning process.

As will be appreciated, vegetables are a perishable crop and the vegetables deteriorate over time. In order to reduce wastage, and maximise the value of a crop, there is a desire, therefore, to preserve the vegetables in a saleable condition for as long as possible. Not only does this increase the likelihood of the vegetables being sold but also allows for vegetables to be transported and/or stored for longer periods of time.

The cleaning of vegetables can also help to preserve the vegetables for longer - by removing, for example, bacteria which would otherwise start to degrade the vegetables.

Cleaning may be performed at a farm on which the vegetables were grown, at a local facility, or at a facility remote from the farm on which the vegetables were grown. Given the relatively high volumes of vegetables concerned, the cleaning of a crop is typically performed in an automated or semi-automated manner, using one or more machines.

The cleaning of vegetables is typically a multi-stage process - e.g. using several water baths and sprays.

As a result, the vegetables are often wet following the cleaning process. Leaving the vegetables wet can promote the degradation of the vegetables, which will be more prone to rooting at an early stage. Accordingly, the cleaning process usually includes a drying stage (at or towards the end of the process).

Passing wet vegetables along a bed of rollers, for example, is a common drying method. The rollers are made from an absorbent material (e.g. a sponge-like material), to remove excess water from earlier in the cleaning process. The rollers made from the absorbent material are typically relatively soft, which is seen as reducing the risk of damage to the vegetables.

The absorbent material in the rollers is periodically changed for new material due to wear and long-term contamination.

The present inventor has noted that these rollers provide an environment which promotes the breeding of bacteria, which may be passed on to vegetables as they pass over the rollers. This bacterial contamination, after the main cleaning process has already occurred, can degrade the vegetables and reduce their shelf-life. In some instances, the bacterial contamination may also or alternatively be potentially harmful to consumers of the vegetables.

The same or similar problems exist with the drying of other crops but also in the drying of non-food items (such as items of recycling). Whilst objects, such as plastic items, for recycling do not normally deteriorate in the same manner, contamination in the drying of the objects may mean that the objects need to be re-washed - which is inefficient.

The present invention seeks to alleviate one or more problems associated with the current methods and/or apparatus for drying objects.

Accordingly, an aspect of the invention provides a dryer apparatus for drying one or more objects, the apparatus comprising: an inlet for receiving one or more objects to be dried; an outlet for outputting the one or more objects from the apparatus; a heated roller array including a plurality of heated rollers located between the inlet and the outlet; and a heater system configured to heat the heated rollers, wherein each heated roller is rotatable to drive movement of the or each object across the heated roller array from the inlet towards the outlet such that the heated rollers at least partially dry the one or more objects.

The heater system may include heating elements, each heating element being provided as part of a heated rollers of the heated roller array.

The apparatus may further include a belt drive system for driving rotation of the heated rollers, wherein the belt drive system includes a belt which is held in contact with the heated rollers and which is configured to be driven with respect to the heated rollers by a first roller.

The belt drive system may further include a second roller and the belt is tensioned between the first and second rollers using a belt tension system.

The belt drive system may further include a roller bed comprising support rollers which are configured to support the belt in contact with the heated rollers. A portion of the belt may be sandwiched between the support rollers and the heated rollers.

Each heated roller may be coupled to a motor configured to drive rotation thereof.

Each motor may be individually controllable by a control system such that the speed of rotation of a first heated roller of the plurality of heated rollers is different to the speed of rotation of a second heated roller of the plurality of heated rollers.

The apparatus may further include an object clearing mechanism which is configured to clear one or more objects from the heated roller array.

The object clearing mechanism may be configured to clear one or more objects from the heated roller array when the heated rollers are not rotating.

The object clearing mechanism may include one or more sweep members which are configured to sweep across the heated roller array to sweep the one or more objects towards the outlet.

The object clearing mechanism may include a sweep belt to drive movement of the or each sweep member.

The apparatus may further include a cooling system comprising pipework and one or more spray nozzles, the or each spray nozzle being configured to spray a liquid onto the heated roller array and the pipework being configured to supply the one or more spray nozzles with the liquid.

The heated rollers may each include a shaft to which is fitted a heating element, and an outer collar which is rotatable about the shaft to provide rotation of the heated roller.

The outer collar of each heated roller may be made of an impermeable and/or non-porous material.

The outer collar of each heated roller may be formed from a metal

The metal may be steel, stainless steel, or aluminium.

Another aspect provides a cleaning system including a dryer apparatus.

The cleaning system may further include one or more cleaning machines and/or one or more conveyors and/or one or more packaging machines.

Another aspect provides a method of operating a dryer apparatus as above, the method comprising: stopping rotation of the heated rollers; and operating the object clearing mechanism to clear one or more objects from the heated roller array.

Another aspect provides a method of operating a dryer apparatus as above, the method comprising: stopping rotation of the heated rollers; and operating the cooling system to spray the liquid onto the heated roller array to cool the heated rollers.

Embodiments of the present invention are described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 shows a side view of an embodiment;

Figure 2 shows a cross-section through a width of an embodiment;

Figure 3 shows rotational directions of a belt and heated rollers of some embodiments; and

Figure 4 shows a sweep member of some embodiments.

With reference to figures 1 to 4, embodiments of the invention include a dryer apparatus 1 which is configured to dry one or more objects. The one or more objects may be, for example, vegetables and may be root vegetables - such as potatoes or carrots. The one or more objects may be items such as empty containers (e.g. cans or bottles) which may be made out of metal or plastic and which may be items for recycling.

The dryer apparatus 1 may include a frame 11 which is configured to support one or more other parts of the dryer apparatus 1 with respect to a ground surface.

Accordingly, the frame 11 may include a plurality of ground engaging feet 111. In some embodiments, at least two ground engaging feet 111 are provided -which oppose each other across a length of the frame 11. In some embodiments, at least four ground engaging feet 111 are provided - with a first pair of ground engaging feet 111 opposing a second pair of ground engaging feet 111 across a length of the frame 11 and each ground engaging foot 111 of each pair opposing the other across a width of the frame 11.

Each ground engaging foot 111 may include a base plate 111a which is configured to engage a ground surface (and may include on or more apertures therethrough for receiving one or more bolts for securing the base plate 111a to the ground surface or another structure). Each ground engaging foot 111 may further include a foot extension 111b which extends away from the base plate 111a and which may be substantially perpendicular to a plane of the base plate 111a. In a typical installation, the base plate 111a may be generally horizontal and the foot extension 111b may be generally vertical.

The foot extensions 111b support one or more other parts of the dryer apparatus 1.

In some embodiments, each foot extension 111b is mountable to a subframe 111 c of the frame 11. The subframe 111c may, therefore, include a plurality of legs 111d with each leg 111d corresponding with a foot extension 111b such that each leg 111 b is mountable to a foot extension 111b. This mounting may be telescopic such that the height of the subframe 111c with respect to the base plates 111a may be adjusted using the telescopic mounting. The telescopic mounting may be fixable in a plurality of different telescopic positions (e.g. by the use of a pin which passes through a wall of the foot extension 111b and leg 111 d).

The subframe 111c may further include one or more beam members 111e which are connected to the legs 11 Id and which connect the legs 11 Id together to form the subframe 111c. The or each beam member 111e may include a horizontal beam, for example. The or each beam member 111e may include at least one beam member 111e which extends along a length of the subframe 111c and at least one beam member which extends along a width of the subframe 111c. In some embodiments, the or each beam member 111e comprises a plurality of beam members which define a generally rectangular table of the subframe 111c.

Respective support members 11 If may form part of the subframe 111c and may be coupled to both a beam member 111e and a leg 111d, to improve the rigidity of the subframe 111c. In some embodiments, each support member 111f comprises a generally triangular member which may be connected to the beam member 111 e and leg 11 Id along respective lengths thereof. Each support member 11 If may be plate-like (i.e. substantially planar) and may define an aperture therethrough - e.g. to reduce the weight of the support member 111f.

The subframe 111c is configured, in some embodiments, to support a belt drive system 13. The belt drive system 13 is configured to drive a belt 131 of the apparatus 1 (and which may form part of the belt drive system 13). The belt 131 may be a continuous belt 131 which is positioned along a length of the apparatus 1 (e.g. of the subframe 111c).

The belt drive system 13 may include a first roller 132 and a second roller 133 which oppose each other across a length of the apparatus 1 (e.g. across a length of the subframe 111c). The belt 131 may pass around the first 132 and second 133 rollers and the first and second rollers 132,133 may be configured to tension the belt 131.

The first and second rollers 132,133 may be carried by respective first and second end members 134,135. The first and second end members 134,135 may be mounted at respective ends of a roller bed 136. The roller bed 136 may form part of the belt drive system 13 and includes a plurality of support rollers 136a which are configured to support the belt 131. The support rollers 136a may be configured to support a length of the belt 131 which extends between the first and second rollers 132,133. The support rollers 136a may, therefore, be located within the belt 131 in some embodiments (although one or more parts of the support rollers 136a may extend beyond the confines of the belt 131). The support rollers 136a and the first and second rollers 136a may be oriented such that their axes of rotation are all parallel with each other (and generally perpendicular to the direction of travel of the belt 131 with respect to these rollers 132,133,136a).

The first roller 132 may be a driven roller such that rotation of the first roller 132 is driven by a first roller motor 132a. In some embodiments, the second roller 133 is also a driven roller and rotation may be driven by a second roller motor or by the first roller motor 132 (e.g. via an arrangement of one or more drive belts). In some embodiments, the second roller 133 and the support rollers 136a (if provided) are non-driven rollers such that these rollers rotate as a result of movement of the belt 131 with respect thereto. The belt 131 may be driven by the first roller 132 (and any other rollers which are driven in a particular embodiment).

The first and second end members 134,135 (and the first and second rollers 132,133 mounted thereto) may be moveable linearly with respect to each other and/or the roller bed 136 to increase or decrease the distance therebetween - i.e. along a longitudinal axis of the apparatus 1. A belt tension system 137 may be provided as part of the belt drive system 13. The belt tension system 137 is configured to move the first and/or second members 134,135 (and/or the first and second rollers 132,133) in order to tension the belt 131. The belt tension system 137 may include, therefore, a threaded shaft 137a and a correspondingly threaded receiver 137b. In some embodiments, the threaded receiver 137b is fixed against rotation with respect to the roller bed 136, and the threaded shaft 137a is configured to move through the threaded receiver 137b - an end of the threaded shaft 137a being secured for linear movement with the associated end member 134,135. Accordingly, the belt tension system 137 is configured to drive linear movement associated end member 134,135 with respect to the roller bed 136.

In some embodiments, the belt tension system 137 may be associated with one of the first and second end members 134,135. In some embodiments, a respective belt tension system 137 is associated with each of the first and second end members 134,135 (such that both of the first and second end members 134,135 can be moved using respective threaded shafts 137a and threaded receivers 137b).

In some embodiments, the belt tension system 137 may include the first and second end members 134,135.

Alternatively, other forms of belt tension system 137 may be provided with a similar function.

In some embodiments, the first and/or second roller 132,133 is mounted such that it is also eccentrically rotatable (and that rotational position selectively fixed) with respect to the roller bed 136 (e.g. with respect to the end member 134,135 to which it is mounted) to fine tune the distance between the first and second rollers 132,133 - and, therefore, the tension of the belt 131.

The dryer apparatus 1 further includes a roller support structure 12 - which may be part of the subframe 111 c or may be connected thereto. The roller support structure 12 defines a plurality of slots 121. Each slot 121 is configured to receive a shaft of a roller - which may include the support rollers 136a (the support rollers 136a being configured to rotate about their respective shafts).

The slots 121 may be defined between tongues 122. In some embodiments, these tongues are upwardly projecting tongues 122. In some embodiments, the roller support structure 12 may include a pair of opposing sets of slots 121 and tongues 121 (e.g. across a width of the apparatus 1) - such that a roller may be mounted to the roller support structure 12 with both ends of the shaft of the roller received by opposing ones of the slots 121.

In some embodiments, the support rollers 136a are mounted to the subframe 111c and are not mounted to the roller support structure 12.

In some embodiments, the apparatus 1 may include a heated roller array 14. The heated roller array 14 includes a plurality of heated rollers 141 which are arranged so as to be rotationally driven by the belt 131 (note that only one heated roller 141 is labelled in figure 1 for simplicity but the figure shows an array of the heated rollers 141). Accordingly, each of the plurality of heated rollers 141 may be positioned so as to contact the belt 131. Movement of the belt 131 with respect to the heated rollers 141 may cause rotation of the heated rollers 141 about respective shafts thereof. The axes of rotation may be generally perpendicular to the direction of travel of the belt 131 (i.e. generally parallel to the rotational axes of the support rollers 136a).

The heated rollers 141 may be supported by the roller support structure 12 -e.g. as described above.

Each heated roller 141 may include a heating element which is configured to heat at least a portion of the heated roller 141. In some embodiments, each heated roller 141 includes a roller surface material which extends around a circumference of the heated roller 141 along a substantial part of the length thereof. The heating element of each heated roller 141 is configured, in such embodiments, to heat the roller surface material.

The heating element of each heated roller 141 is, in some embodiments, an electrically operated heating element. In some embodiments, the heating element is secured to the shaft of the heated roller 141 and the roller surface material forms an outer collar of the heated roller 141 - the outer collar being configured for rotation with respect to the shaft and heating element. The outer collar may, therefore, be supported on the shaft of the heated roller 141 by one or more bearings. As used herein, reference to the rotation of a heated roller 141 may be a reference to rotation of the outer collar of the heated roller 141 with respect to the shaft of the heated roller 141.

The roller surface material (e.g. the outer collar) of each heated roller 141 may be formed from a metal (such as steel, stainless steel, or aluminium). In some embodiments, the roller surface material is generally impermeable and/or non-porous such that the roller surface material has a reduced risk of bacterial build-up.

The roller surface material may be a relatively good conductor of heat.

An outer surface of the outer collar of each heated roller 141 may be generally free from bristles, or protrusions, or the like. In some embodiments, the outer surface of the outer collar is generally smooth.

The heating element of each heated roller 141 is configured to receive electrical power from a power distribution system which is configured to deliver electrical power to the heating elements and to control the operation thereof. In some embodiments, the heating elements may be controlled individually or in groups. Accordingly, the apparatus 1 may be configured such that there is a predetermined temperature profile across the heated roller array 14 - e.g. hotter at towards one end and cooler towards the other, or vice versa. In some embodiments, at least one heated roller 141 closer to an inlet 15 is hotter than at least one heated roller 141 closer to an outlet 16.

The heated roller array 14 may form a bed of rollers, with each heated roller 141 relatively close to its neighbour or neighbours (i.e. the separation of the heated rollers 141 is less than the minimum expected dimension of the objects to be dried using the apparatus 1 such that the objects are unlikely to pass between the heated rollers 141).

The objects to be dried pass over the heated roller array 14 on a first side thereof. The second side of the heated roller array 14 may be adjacent the belt 131. The belt 131 may, therefore, be sandwiched between the heated roller array 14 and the roller bed 136. The roller bed 136 may, therefore, support the belt 131 in the region of the heated roller array 14, this may serve to improve contact between the belt 131 and the heated rollers 141.

The direction of rotation of the belt 131 is shown in the accompanying figures and referenced with the letter “R”. The corresponding direction of rotation of the heated rollers 141 is shown in figure 3 in particular with the letter “H”.

The apparatus 1 may further include the inlet 15 at one end of the heated roller array 14 (i.e. towards one end of the apparatus 1) and the outlet 16 at an opposing end of the heated roller array 14 (i.e. towards an opposing end of the apparatus 1). Accordingly, objects to be dried may enter the apparatus 1 via the inlet 15, pass through the apparatus 1 over the heated roller array 14, and leave the apparatus 1 via the outlet 16. The inlet 15 may include a ramp which is configured to allow the objects to pass down the ramp to the heated roller array 14. The outlet 16 may include a ramp which is configured to allow the objects to pass down from the heated roller array 14 to leave the apparatus 1.

The apparatus 1 may include a belt cleaning device 131a which is configured to clean the belt 131 (or part thereof). Accordingly, the belt cleaning device 131 may be mounted adjacent the first or second roller 132,133 and may comprise a brush member which presses against a surface of the belt 131 as it passes around the first or second roller 132,133. The brush member may include one or more resilient bristles which are configured to brush dirty or other contaminants from the surface of the belt 131. A container may be provided beneath the belt cleaning device 131a to collect the material which has been removed from the belt 131 by the belt cleaning device 131a. The material which is cleaned from the belt 131 may include, for example, soil from the objects being dried by the apparatus 1. Cleaning this material from the belt 131 may help to reduce the risk of contamination of objects being dried but also helps to increase the operating life of the belt 131 (as this material may be abrasive and cause excessive wear to the belt 131 during operation of the apparatus 1).

In some embodiments, the apparatus 1 includes an object clearing mechanism 17. The object clearing mechanism 17 is configured to clear one or more objects from the heated roller array 14 in the event of a shutdown of at least part of the apparatus 1 such that the heated rollers 141 no longer rotate. Rotation of the heated rollers 141 causes movement of the objects across the heated roller array 14. Therefore, if rotation of these heated rollers 141 stops, then the objects will remain in contact with the heated rollers 141 and may be damaged (e.g. because the same parts of the objects are in contact with the heated rollers 141 for an extended period of time).

The object clearing mechanism 17 could take a number of different forms. In some embodiments, the object clearing mechanism 17 includes one or more sweep members 171 which are configured to sweep across the heated roller array 14 to sweep any objects resting thereon to one end or another of the heated roller array 14. The sweep may be from the inlet 15 end of the heated roller array 14 towards the outlet 16 end of the heated roller array 14 - such that objects may leave the apparatus 1 via the outlet 16 once swept from the heated roller array 14.

The object clearing mechanism 17 may, therefore, include a sweep drive system 172 which is configured to drive movement of the or each sweep member 171 - e.g. from the inlet 15 end to the outlet 16 end of the heated roller array 14.

The object clearing mechanism 17 may be supported by the frame 11 (e.g. by an extension of the subframe 111c) with respect to the heated roller array 14 such that the or each sweep member 171 is configured to sweep a side of the heated roller array 14 which opposes the side in contact with the belt 131. In other words, in the normal orientation of the apparatus 1, the object clearing mechanism 17 may be generally located above the heated roller array 14.

The or each sweep member 171 may comprise a flexible sheet 171a which may be moved (i.e. swept) along the heated roller array 14. As will be appreciated, the heated roller array 14 presents an undulating profile (defined by the plurality of heated rollers 141). The or each sweep member 171 may be sufficiently flexible such that a free end of the sweep member 17 may substantially follow the undulating profile of the heated roller array 14.

The free end of the or each sweep member 171 (i.e. of the flexible sheet 171a of that sweep member 171) may include a rigid edge piece 173. The rigid edge piece 173 is more rigid than the flexible sheet 171a of the or each sweep member 171 and is configured to push one or more objects across at least part of the heated roller array 14. The rigid edge piece 173 may be formed of plastics or metal (such as aluminium, steel or stainless steel), for example.

In some embodiments, the free ends of the or each sweep member 171 include a brush piece including a plurality of resilient bristles. The brush piece may be mounted to the rigid edge piece 173 or may be provided instead of the rigid edge piece 173. The resilient bristles may be configured to engage and push one or more objects along the heated roller array 14 but to deflect to prevent too great a force being applied to the object or objects.

In some embodiments, the rigid edge piece 171b and/or the brush piece is angled away from the direction of travel of the associated sweep member 171 (relative to the flexible sheet 171a).

In some embodiments, a plurality of sweep members 171 is provided. Each sweep member 171 may be configured to push one or more objects in a particular direction (e.g. towards the outlet 16 end of the heated roller array 14). However, typically, an object does not get pushed from the inlet 15 end to the outlet end 16 by a single one of the plurality of sweep members 171. Instead, each sweep member 171 pushes an object part of the way before passing the object (which is then pushed further by the next sweep member 171).

The one or more sweep members 171 may each have a width which is generally equal to or greater than a width of the heated roller array 14 (or the collars of the heated rollers 141 thereof). In some embodiments, the or each sweep member 171 comprises a single flexible sheet 171a but in some embodiments the or each sweep member 171 may comprise a plurality of flexible sheets 171a. In some embodiments not all sweep members 171 extend across the entire width of the heated roller array 14 (or the collars of the heated rollers 141 thereof) - in such embodiments, there may be a plurality of sweep members 171 which are collectively extend across the entire width but which may or may not be aligned with each other (with respect to the length of the heated roller array 14).

In some embodiments, the one or more sweep members 171 are mounted to a sweep belt 172a of the sweep drive system 172. The mounting may be via a flexible joint (such that the or each sweep member 171 can rotate about the mounting with respect to the sweep belt 172a). The mounting may be at an end of the or each sweep member 171 which opposes the free end across a length of the sweep member 171.

The sweep belt 172a may be a continuous belt which may be arranged generally parallel to the heated roller array 14 (e.g. to the belt 131). The sweep belt 172a may be spaced apart from the heated roller array 14 by a distance which is less than the length of the or each sweep member 171 (such that the or each sweep member 171 may contact the heated roller array 14 to perform the sweep operation). In this regard, the spacing mentioned above may refer to the spacing of an adjacent run of the sweep belt 172a (or the entire sweep belt 172a).

The sweep belt 172a may be supported by a first sweep belt roller 172b and a second sweep belt roller 172c which are arranged at opposing ends of the sweep drive system 172. The two sweep belt rollers 172b,c form part of the sweep drive system 172. The sweep belt 172a may be tensioned by these two sweep belt rollers 172b,c, and at least one of the sweep belt rollers 172b,c may be driven or driveable - e.g. by a sweep belt drive motor 172d which may be mounted to the extension of the subframe 111c which carries the sweep drive system 172. Indeed, the sweep belt drive motor 172d may form part of the sweep drive system 172.

In some embodiments, the sweep belt 172a has an adjacent run (which is adjacent to the heated roller array 14) and a remote run (which is relatively further away from the heated roller array 14). In some embodiments, the or each sweep member 171 is configured to perform the sweep operation - i.e. to push one or more objects across the heated roller array 14 - when the part of the sweep belt 172a to which that or those sweep members 171 are mounted is on the adjacent run. When that or those sweep members 171 are mounted to the part of the sweep belt 172a which is on the remote run, then that or those sweep members 172a may rest against the sweep belt 172a in an inoperative position. As will be understood, as the sweep belt 172a moves around the sweep belt rollers 172b, the parts of the sweep belt 172a on the adjacent and remote runs changes. As a sweep member 171 mounted to a part of the sweep belt 172a moves around one of the sweep rollers 172b,c (e.g. the first sweep roller 172b) is will move (with respect to the sweep belt 172a and/or the heated roller array 14) into an operative position in which it can sweep across the heated roller array 14 to perform the sweep operation.

In some embodiments, the or each sweep member 171 includes a sweep shaft 171c to which the flexible sheet 171a is mounted (see figure 4 in particular). This mounting may be achieved by wrapping a part of the flexible sheet 171c around the sweep shaft 171c. The sweep shaft may be carried by the sweep belt 172a. In some embodiments, the sweep belt 172a (which may be a round belt, a v-belt, a conveyor belt, even a drive chain (in which case the sweep belt rollers 172b,c may be sprockets)) may include a first and second continuous sweep belt 172a with the first and second continuous sweep belts being configured to support opposing ends of the sweep shaft 171c (or shafts 171c if there are multiple sweep members 171). The first and second sweep belts may be carried by their own respective first and second sweep belt rollers 172b, 172c - with a pair of such sweep rollers 172b,c located either side of the sweep shaft 171c (i.e. opposing each other across a width of the apparatus 1). The second sweep belt rollers 172c may be coupled by a shaft 173 such that they rotate together (driven by the sweep belt drive motor 172d). Accordingly, the sweep members 171 of such embodiments which are mounted on a part of the sweep belts 172a which are on the remote run may hang downward and may or may not contact the heated roller array 14.

In some embodiments, the object clearing mechanism 17 is operated only when one or more objects need to be cleared from the heated roller array 14. This may be when the heated roller array 14 is, for example, hot but the heated rollers 141 are not rotating. In some embodiments, the object clearing mechanism 17 is run when the heated rollers 141 are rotating, in order to encourage the movement of objects across the heated roller array 14.

In some scenarios it may be necessary to cool the heated roller array 14 relatively quickly. This may occur, for example, in an emergency shutdown situation. The heated rollers 141 of the heated roller array 14 may, however, store heat for a relatively long period of time and this could, for example, pose a safety concern and/or a fire risk - particularly in an emergency shutdown scenario. Therefore, in some embodiments, the apparatus may further include a cooling system 18. The cooling system 18 may include pipework 181 configured to deliver a cooling liquid (such as water) to the heated roller array 14. Accordingly, the pipework 181 may include one or more spray nozzles 181a which are each configured to spray the liquid carried by the pipework 181 onto the heated roller array 14. The pipework 181 may be located such that the or each spray nozzle 181a can spray the liquid onto the heated roller array 14. In some embodiments, the pipework 181 may be substantially located within a space defined between the heated roller array 14 and the object clearing mechanism 17. In some embodiments, the pipework 181 may be substantially located adjacent a part of the object clearing mechanism 17 which is remote from the heated roller array 14 (e.g. above the object clearing mechanism 17 with the apparatus 1 in the normal orientation). In some embodiments, the pipework 181 is located substantially alongside the heated roller array 14 such that the or each spray nozzle 181a may be directed generally sideways across the width of the heated roller array 14.

The pipework 181 may include one or more pipes which run along a length of the heated roller array 14 and/or one or more pipes which run along a width of the heated roller array 14 (with spray nozzles 181a located along those pipes).

The pipework 181 is, as will be understood, connected to a source of the liquid - such as a mains water supply or a water supply tank. A pump may be provided between the source of the liquid and the spray nozzles 181a to ensure that the liquid is sprayed from the nozzles 181a.

In some embodiments, the heated roller array 14 includes around twenty heated rollers 141; however, the heated roller array 14 may include two or more heated rollers 141. Indeed, embodiments may include, five, ten, fifteen, twenty, twenty five, thirty, or more heated rollers 141.

In some embodiments, the number of support rollers 136a is generally around half the number of heated rollers 141. In some embodiments, each support roller 136a is generally aligned with a heated roller 141 such that the belt 131 is pressed by the support roller 136a into or towards the heated roller 141 with which it is generally aligned.

Although embodiments have been described with reference to a belt 131 which drives rotation of the heated rollers 141, other configurations are possible. Indeed, the belt 131 may be a conveyor-type belt - which may have a width generally equal to (or less than) the width of the heated rollers 141 (or the collars of the heated rollers 141) - or may be a round belt, a v-belt, a ribbed belt or the like (such as a drive chain). In some embodiments, the first and second rollers 132,133 may be respective sprockets. The belt 131 may, in some embodiments, be coupled to the heated rollers 141 via one or more pulleys - and the roller bed 136 may not be provided in some such embodiments.

In some embodiments, each heated roller 141 is driven via one or more gears. In some embodiments, each heated roller 141 is coupled to its own motor (or groups of heated rollers 141 may be coupled to a single motor) to drive rotation thereof. In such embodiments, the speed of rotation of one heated roller 141 may be controlled to be different to the speed of rotation of another of the heated rollers 141 - by appropriate control of the motors driving the heated rollers 141.

In some embodiments, the apparatus includes one or more guard panels 19 configured to restrict access to the heated roller array 14 - e.g. to the space defined between the heated roller array 14 and the object clearing mechanism 17. These guard panels 19 may form side panels of the apparatus 1 and may be supported by the subframe 111c. In some embodiments, the one or more guard panels 19 are insulated guard panels and, as such, include a layer of heat insulating material. Accordingly, the or each guard panel 19 may be formed from a metal sheet which is at least partially lined with a heat insulating material (e.g. a foam insulation material). The heat insulating material may be coated in an impermeable membrane to reduce the ingress of water into the insulating material.

In some embodiments, the one or more guard panels 19 include at least one panel which extends across a top of the apparatus 1. Such a guard panel 19 may be located on the side of the object clearing mechanism 17 and/or cooling system 18 pipework 181 which is remote from the heated roller array 14. Accordingly, in some embodiments, one or more guard panels 19 (which may include a layer of heat insulating material) may substantially surround the heated roller array 14, and the object clearing mechanism 17 (if provided, but excluding the sweep belt drive motor 172b in some embodiments), and at least part of the pipework 181 of the cooling system 18 (if provided). The one or more guard panels 19 may, therefore, form an insulating canopy for the apparatus 1. In some embodiments, the insulating material is provided separately from the one or more guard panels 19 - such that each can be removed independently. A ventilation system may be provided as part of the apparatus 1 to circulate air from inside the apparatus with fresh air from outside of the apparatus 1. As will be appreciated, due to operation of the heated rollers 141, the air inside of the apparatus 1 may be relatively damp (i.e. high humidity) and replacing this air with drier air (i.e. with a lower humidity) may improve the effectiveness of the drying in some embodiments. In some embodiments, the ventilation system is configured to remove air from the apparatus 1, dry the air, and recirculate that air back into the apparatus 1. This may result in the collection of water - which may be drained away or used in some other part of the process of cleaning the objects.

As will be understood from the above description, one or more objects to be dried may be passed to the dryer apparatus 1 of embodiments of the present invention. The one or more objects may enter the apparatus 1 via the inlet 15 and then be passed across the heated roller array 14 towards the outlet 16 and out of the apparatus 1. The movement of the objects across the heated roller array 14 may be driven by rotation of the heated rollers 141 of the heated roller array 14. As the objects pass over the heated rollers 141 excess water will evaporate from the objects - the heated rollers 141 being heated by use of their respective heating elements. Movement of the objects across the heated roller array 14 may be encouraged by use of the object clearing mechanism 17 in some embodiments.

When the apparatus 1 is shutdown, a shutdown sequence may be performed. This shutdown sequence may include stopping the heating of the heated rollers 141 but continuing to rotate the heated rollers 141 after heating has been stopped. The sequence may further include operating the object clearing mechanism 17 and/or the cooling system 18.

The dryer apparatus 1 of embodiments may be provided as part of a cleaning system for objects. The cleaning system may include one or more other machines which are configured, for example, to clean the objects. The cleaning system may include one or more conveyors to pass the objects between parts of the system and may include packaging equipment to package the objects for distribution.

In some embodiments, a control system is provided and the control system may control the operation of one or more aspects of the apparatus 1. This may include shutdown sequence, the operation of the cooling system 18, the temperature of the heated rollers 141, and the speed of rotation of the heated rollers 141, etc.

Although embodiments have been described with reference to heated rollers 141 with heating elements located inside each heated roller 141, there may also be embodiments in which there is no heating element inside each heated roller 141. For example, a heated plate may be located on the side of the heated roller array 14 which is remote from the side over which the one or more objects pass. The heated plate may heat the outer collar of the heated rollers 141 (this may be used in combination with any of the embodiments disclosed herein).

In some embodiments, the shaft of each heated roller 141 includes a fluid inlet and a fluid return such that fluid can be circulated through the shaft (via the fluid inlet and fluid return). Such embodiments may further include a fluid (e.g. a liquid such as water) source (e.g. a tank) and a heater configured to heat the fluid (in the water source or elsewhere). Accordingly, heated fluid may be circulated through the shafts of the heated rollers 141 in order to heat the heated rollers 141.

In some embodiments, the heated rollers 141 are driven by further rollers which are located on the side of the heated roller array 14 which opposes the side over which the or each object passes. The further rollers may include a heating element and may be driven by one or more motors (e.g. via one or more gears, belts, or the like). The further rollers may, therefore, heat the heated rollers 141 (even if the heated rollers 141 do not include heating elements).

As will be understood, the heating element which may (or may not) form part of each heated roller 141 along with the above described alternatives, all comprise examples of a heater system which is configured to heat the heated rollers 141 of the heated roller array 14.

In some embodiments, one or more heaters may be provided to heat the air on the side of the heated roller array 14 over which the or each object passes. The or each heater may be provided to one or more sides of the heated roller array 14 and/or above the heated roller array 14.

The present inventors have found that embodiments of the present invention using heated rollers with relatively hard outer collars (e.g. made of metal as described herein) do not cause excessive damage to the objects to be dried. Furthermore, the removal of the sponge-like material used on drying rollers of the prior art, means that contamination of the objects is likely to be reduced.

When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

1. A dryer apparatus for drying one or more objects, the apparatus comprising: an inlet for receiving one or more objects to be dried; an outlet for outputting the one or more objects from the apparatus; a heated roller array including a plurality of heated rollers located between the inlet and the outlet; and a heater system configured to heat the heated rollers, wherein each heated roller is rotatable to drive movement of the or each object across the heated roller array from the inlet towards the outlet such that the heated rollers at least partially dry the one or more objects.

2. An apparatus according to claim 1, wherein the heater system includes heating elements, each heating element being provided as part of a heated rollers of the heated roller array.

3. An apparatus according to claim 1 or 2, further including a belt drive system for driving rotation of the heated rollers, wherein the belt drive system includes a belt which is held in contact with the heated rollers and which is configured to be driven with respect to the heated rollers by a first roller.

4. An apparatus according to claim 3, wherein the belt drive system further includes a second roller and the belt is tensioned between the first and second rollers using a belt tension system.

5. An apparatus according to claim 3 or 4, wherein the belt drive system further includes a roller bed comprising support rollers which are configured to support the belt in contact with the heated rollers.

6. An apparatus according to claim 5, wherein a portion of the belt is sandwiched between the support rollers and the heated rollers.

7. An apparatus according to claim 1 or 2, wherein each heated roller is coupled to a motor configured to drive rotation thereof.

8. An apparatus according to claim 7, wherein each motor is individually controllable by a control system such that the speed of rotation of a first heated roller of the plurality of heated rollers is different to the speed of rotation of a second heated roller of the plurality of heated rollers.

9. An apparatus according to any preceding claim, further including an object clearing mechanism which is configured to clear one or more objects from the heated roller array.

10. An apparatus according to claim 9, wherein the object clearing mechanism is configured to clear one or more objects from the heated roller array when the heated rollers are not rotating.

11. An apparatus according to claim 9 or 10, wherein the object clearing mechanism includes one or more sweep members which are configured to sweep across the heated roller array to sweep the one or more objects towards the outlet.

12. An apparatus according to claim 11, wherein the object clearing mechanism includes a sweep belt to drive movement of the or each sweep member.

13. An apparatus according to any preceding claim, further including a cooling system comprising pipework and one or more spray nozzles, the or each spray nozzle being configured to spray a liquid onto the heated roller array and the pipework being configured to supply the one or more spray nozzles with the liquid.

14. An apparatus according to any preceding claim, wherein the heated rollers each include a shaft to which is fitted a heating element, and an outer collar which is rotatable about the shaft to provide rotation of the heated roller.

15. An apparatus according to claim 14, wherein the outer collar of each heated roller is made of an impermeable and/or non-porous material.

16. An apparatus according to claim 15, wherein the outer collar of each heated roller is formed from a metal

17. An apparatus according to claim 16, wherein the metal is steel, stainless steel, or aluminium.

18. A cleaning system including a dryer apparatus according to any preceding claim.

19. A cleaning system according to claim 18 further including one or more cleaning machines and/or one or more conveyors and/or one or more packaging machines.

20. A method of operating a dryer apparatus according to any of claims 8 to 12, the method comprising: stopping rotation of the heated rollers; and operating the object clearing mechanism to clear one or more objects from the heated roller array.

21. A method of operating a dryer apparatus according to claim 13, the method comprising: stopping rotation of the heated rollers; and operating the cooling system to spray the liquid onto the heated roller array to cool the heated rollers.

22. A dryer apparatus substantially as herein described with reference to the accompanying drawings.

23. A cleaning system substantially as herein described with reference to the accompanying drawings.

24. A method of operating a dryer apparatus substantially as herein described with reference to the accompanying drawings.

25. Any novel feature or novel combination of features described herein.