CA2046655A1

CA2046655A1 - Conveyor

Info

Publication number: CA2046655A1
Application number: CA002046655A
Authority: CA
Inventors: Allan Richmond; Alan Hodgson
Original assignee: Individual
Current assignee: Huwood Ltd
Priority date: 1989-02-10
Filing date: 1990-02-01
Publication date: 1990-08-11
Also published as: CN1021647C; AU635524B2; ZA90781B; GB8903015D0; EP0456744A1; WO1990009333A1; BR9007114A; AU5080190A; CN1044792A; JPH04506501A; IN175170B

Abstract

The present invention provides a conveyor (1) suitable for use in conveying bulk material (2), especially for the elevation of such material. The conveyor (1) comprises an endless carrier belt (3) and an endless bulk material engagement (4) having a plurality of paddles (10) with a shape corresponding to the cross section of a channel (7) defined by the carrier belt (3), so that the paddles (10) have a close fit with the sides (3a) and base of the channel (7). At least one of the carrier belt (3) and the engagement means (4) is driven and drive is transferred therebetween by contact between the paddles (10) and the channel (7) to the other.
The belt (3) and the connector means (8) of the engagement means (4) are formed and arranged to follow a substantially identical path in a vertical plane along the conveying path where said belt (3) and engagement means (4) interengage whereby movement of the paddles (10) and belt (4) is maintained in substantial synchronism. With a conveyor of the invention uphill and downhill conveying of a wide variety of bulk materials (2) over steep inclines can be effected with a high load capacity.

Description

,. . . ... . .

CONVEYOR
The present invention relates to a conveyor suitable for use in conveying bulk material and especially to such conveyors capable of elevating such material.

Most commonly bulk material which requires to be elevated at a more or less steep angle of rise, is conveyed in bucket conveyors. Such conveyors have various disadvant-ages though including cost and relative complexity of construc~ion, noisy operation, spreading of dust, etc., inconvenient loading due to the need to load individual buckets, and difficulty of clearing of the individual buckets which is further aggravated by the tendency for material to adhere to and be retained in such buckets.
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More recently there have been proposed so called cover belt conveyors, in which two belts are inter-engaged along a conveying path so as to seal the bulk material being carried within a confined space defined between the belts.
In one conveyor of this type, there is provided a first carrier belt and a second closure belt both of which are generall~ "U"-shaped with corrugated sides. The carrier belt further has a plurality of regularly spaced upstanding plates which divide the carrier belt interior into a plurality of individual compartments. With this type of conveyor, however, the loading arrangements possible are relatively restricted and cumbersome. In 2~ addition there is a substantial tendency or the bulk material, especially those types which are somewhat sticky or not particularly free flowing, to become lodged in the corrugations and/or in the corners between the upstanding plates and the base of the carrier belt. ~n . .
addition these same fea~ures are particularly awkward and difficult to clean thereby resulting in significant additional operating costs. In the meantime, it will further be appreciated, that the effective conveying capacity of the conveyor will be reduced by an amount : :- : , , .

.

,~ '~ -` .. .

corresponding to the volume of material trapped in the conveyor.

It is an object of the present invention to avoid or minimise one of more of the above disadvantages.

The present invention provides a conveyor suitable for use in conveying bulk material which conveyor comprises an endless carrier belt and an endless bulk material engage-ment means^
characterised in that said bulk material engagement means comprises elongate flexlble connector means mounting a plurality of spaced apart paddles, said carrier belt and endless connector means being mounted for movement along a conveying path with said paddles projecting substantially into the interior of a channel defined by said carrier belt at least alony said conveying path, in close proximity to the sides and base of said channel so as to engage bulk material within said channel in use of the conveyor and transfer drive forces between said connector means and said bulk material during uphill or downhill conveying of said bulk material, said paddles having a shape, at least at their distal ends, corresponding generally to the cross-sectional shape of said channel, and with said connector means and said belt following a substantially identical path in a vertical plane along the con~eying path where said belt and engagement means interengage, whereby movement of said paddles and said belt therealong is maintained in substantial synchronism.

It will of course be appreciated that the belt and bulk material engagement means are normally only required to move together Iwith the paddles projecting into the channel) along inclined conveying paths so that where the conveyor is desired to include a generally horizontal conveying path section, the carrier belt may extend beyond the endless connector means, the latter being w ~ i * ~ i . . ~ ~ r ~ ~ ~ ., ~, ~, v i 3 ~ A ~ ~
.

guided towards and away from the carrier belt at/or proximity to end portions of the inclined conveying path section.

Thus with a conveyor of the present invention uphill and downhill conveying of bulk material can be effected substantially without relative movement between the paddles and carrier belt in a direction along the - conveyiny path thereby avoiding wearing of these parts and/or damage thereto resulting from such relative movement. In addition such an arrangement allo~s a wide variety of materials to be conveyed over steep inclines with varying or intermittent feed rates. Thus friable materials can be readlly handled with little or no degradation and wet, sticky, frozen, irregular shaped, andtor a~rasive material can be carried wlth minimal accummulation on the conveyor and/or damage thereto.
The bulk material may moreover range in size from fines to relatively large lumps e.g. 0.6m size on a 2m wide belt.

Also with a conveyor of the present invention it is possible substantiaIly to fill the carrier belt with bulk material thereby allowing a high load capacity to be achieved for a given size of conveyor, and quite steeply inclined, e.g. 70 or more to the horizontal, conveying paths to be safely negotiated which in turn can result in substantial economies in the length of conveyor required and its construction, allow increased flexibility in the routing of the conveying path and reducing site area requirements for the conveyor thereby minimising the site area sterilised by conveyors. .At the same time the conveyor of the present invention permits easy and flexible loading arrangements and minimises cleaning requirements as well as facilitating such cleaning as may be required. The endless carrier belt and bulk material engagement means will generally be disposed in a back-to-back arrangement, being guided ' 2 ~
~V 7i~ 7_ i,i i .~' ~"'~
....

towards and away from each other at the beginning and end of said conveying path. Thus by effectively and, along their respective return pathways, actually separating, at least a substantial part of the material engagement component from the carrier component of the conveyor, the problems of material lodging and being ;
retained between the two are further minimised. Moreover ~`-since the carrier belt itself is merely required to support and carry the material without being required to provide any special additional function it can be made of quite plain construction e.g. a deformable flat belt, which ls not only more economical than other mo~e complex forms of carrler but also mlnimises the problem of material lodging in it and is easy to clean.
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The conveyor of the invention may be used with various forms of drive arrangement including driving of the endless ~onnector means only and d iving o~ both the elevator and the carrier belt. In the former case, the carrier belt will be carried along indirectly by the friction between the bulk material engaged by the paddles and the carrier belt, or by direct engagement of the paddle edges with the carrier belt. Such arrangements are generally preferred since they avoid the need for using a relatively highly tensioned carrier belt, thereby allowing more economical belt constructions to be employed and/or providing increased belt life, lower replacement costs, and cheaper repairs by means of mechanical jointing instead of vulcanizing. Indeed the carrier belt components may be substantially identical to those used in conventional horizontal channel belt conveyors thereby simpllfying design work and increasing reliability through the use of standard proven components.
It will also be appreciated that the use of low tension belt systems significantly reduces the risk of belt breakage and conveyor down-time resulting therefrom.
Any suitable form of flexible connector means may be us d in the conveyor of the invention including for .

~ 3!~!f~3 example, chains and cables. Conveniently two such connector elements are used, disposed at either side of the channel form carrier belt.

Preferably the engagement means paddles are generally curved so as to define together with the channel defined by the carrier belt a generally scoop shaped receptacle, each said paddle forming a generally upright generally transverse wall curving round at opposite sides in a directior. up the inclined conveying path. Generally said oppGsite sides of the paddle means progressively reduce in depth in said direction. Advantageously the paddle means havç generally transversely outwardly - projecting mountlng wings formed and arranged so as to extend over and down alongside the side walls of the channel formed by the carrier belt, for securing o~ the paddles to respective endless connector elements.

With such paddles the angle of inclination of the conveying path and/or the carrying capacity of the conveyor may be maximised without however the risk of significant accumulation and sticking of the bulk material on the carrier belt or bulk material engagement means.

The conveyor of the invention also allows a wide range of feed arrangements to be used including side loading, loading on inclined or horizontal belt runs, and loading at intermediate levels, thereby avoiding the need for transfer points and tandem conveyors.

If desired the paddles may be further provided with resiliently deformable edge seals, at their carrier-belt co-operating periphery, to minimise escape of bulk material therebetween and to maximise drive transmission therebetween. Also they may be provided with deformable or deflectable central portions at their upper edges remote from said carrier belt engaging periphery, so ~ " ,: . ~:

. ' - - ' :

that in the event of larger pieces of material becoming lodged between the driving and return runs of the elevator, these portions can give way and ride over the piece to avoid jamming of the elevator and/or possible damage to conveyor. The portions may be of flexible material'such as rubber secured in the principal plane of the paddle or may be in the form of sm~ll rigid inset panels hingedly mounted and retained in the principal plane of the paddle by suitable spring means.

In general the paddles are disposed so as to project generally at right angles from their direction of travel along the conveying path but advantageously they may be formed and mounted on the elevator drive trans-mission member so as to be inclined rearwardly with respect to an uphill direction along the conveying path. With such an arrangement with effective fill capacity of the individual compartments defined by the paddles within the carrier belt in a rising conveyor of invention may be significantly increased. In addition discharg~ from such a conveyor is facilltated and any tendency of the bulk material to adhere to the paddles as they are separated away from the carrier belt, reduced.

As noted above, the elongate connector means could be in the form of a belt and this will help further to contain the bulk material within the conveyor. In the case of a chain or cable connector means there may be provided, if desired, a cover plate means above the bulk material engagement means along the conveying path in order to minimise escape of dust etc.

For the avoidance of doubt, it should be noted that the present invention extends to conveyors with both horizontal and rising sections in which elevator means are provided only at the rising sections of the carrier belt, as well as to conveyor installations such as - : .

horizontal bunker conveyors and moving bed chain conveyors in which the carrier belt extends only substant-ially horizontally, short horizontally extending lengths of the bulk material engagement means being provided to boost driving of the horizontal carrier belt with the bulk material thereon, by engagement of the paddles with the bulk material or belt.

Any suitable arrangement known in the art for routeing of the return segments of the carrier belt and elevator may be used. In general the elevator will most conveniently be returned above the carrier belt with the carrier belt and elevator in a back-to-back arrangement.
Alternatively though, the return segment of the elevator could be routed around the carrier belt below the return lS run of the carrier belt.
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Various suitable forms of loading arrangements may be employed with conveyors of the present invention including end loading, side loading, and top loading which may in turn be directly "through" the elevator the material being allowed to fall through elther side of the paddles into the carrier belt either through both forward and return runs of the elevator or, more commonly through the forward, conveying, run only of the elevator as or just after it is brought into the "V" or "U"-shaped channel defined by the carrier belt, the return run being routed sufficiently far away from the conveying path at that point to allow introduction of material therebetween. In another possible arrangement there is provided a short conduit encasing the elevator immediately upstream of the beginning of the conveying path and extending along part of the return path of the elevator to permit top loading into the upstream end of the conduit, the material then being carried round the conduit by the elevatox into the "U"-shaped channel defined by the carrier belt. In the case of end loading the material is loaded onto part of the carrier belt . .~. . , . ' , ~

~ J~j extending horizontally upstream of a position at which the elevator is brought fully together with the carrier belt.

Further preferred features and advantages of the invention 5 will appear from the following detailed description given by way of example of some preferred embodiments illustrated with reference to the accompanying drawings in which:
Fig. 1 is a side elevation of a conveyor of the invention;
Figs. 2 to 4 are detailed views of a paddle of the lO conveyor of Fig. 1 shown on an enlarged scale and in which:
Fig. 2 is a side elevation;
Fig. 3 is an end elevation; and Fig. 4 is a plan view; and Fig. 5 is a schematic side view of another conveyor installation o the invention ~or use in downhill conveying.
Fig. l shows a conveyor l suitable for use ln uphill conveying bulk particula1:e material 2. The conveyor 1 comprises a carrier belt 3 and a bulk material engagement means 4. The carrier belt 3 extends around return pulleys S and over guide rollers 6 (See Fig. 3) formed and arranged so as to define a flat-bottomed generally "V"-shaped channel 7 along the conveying path of the conveyor l.

The bulk material engagement means 4 comprises a flexible endless connector means member in the form of two chains 8 mounting 9 a plurality of spaced apart upstanding paddles in the form of generally arcuate plates 10 (See Fig. 4) corresponding generally to the cross-sectional shape of the channel 7 defined by the carrier belt 3 and guide rollers 6 ~see Fig. 3). As may be seen in more detail in 30 Figs. 2 to 4 the arcuate plates lO have a central generally upright wall portion 11 (inclined slightly forward in the conveying direction) extending tranversely of the carrier belt and cl~rving round at either side into side walls 12 of reducing depth extending generally in the uphill 35 direction of the conveyor 1, so that the paddle plates lO
form, together with the carrier belt, generally scoop-. .

~0 70/;~7 ~ ,,, ~ 3 shaped receptacles 13 for holding and increasing uphillpropulsion of the bulk material 2 by reducing escape thereof from the carrier belt 7 during uphill conveying.
In addition the outer circumferential edge 14 of each .~ 5 plate 10 is provided with a seal element 15 for engagement with the carrier belt 3 further to minimise escape of material 2. The use of such curved shaped plates 10 also has the further advantage of maximising the strength of the paddles and their impact resistance as well as heIping to centralise the bulk material 2 in the carrier belt 3 thereby improving belt tracking. At either side of the arcuate plates 10 are provided outwardly projecting wings ~ lOa which are formed so as to rise up over the inclined - sides 3a of the troughed carrier belt before depending downwa~d].y to the chain mountings 9 at a level generally alongside the lower edge lla o the central portion 11 o~
the padd].e plate 10.

As shown in Fig. 1 the bulk material engagement means 4 extends around return guides above the conveying path which are in the form of. sprockets 16, at least one of which can be used for driving or braking thereo~ during uphill or downhill conveying, respectively.

The chains 8 may be supported between the return sprockets 16 on suitable support sprockets or rollers 17 as shown under the return run. Conveniently though in their conveying run the chains 8 are supported substantially solely through the paddles 10 resting on the carrier belt 3 thereby also maximising frictional engagement therewith and hence drive transmission thereto or therefrom.

The carrier belt 3 is returned 5 below the conveying path the belt 3 being supported in the form o a shallow flat bottomed "V"-shaped channel 7 along the return path on the guide rollers 6. It will be appreciate~ that with a substantially plain belt configuration as shown there - - ~ J ,~:- U lJ ~

will be :Little danger o material 2 lodging in or adherincJ
to the belt and any cleaning that may be required can be readily effected.

The bulk material engagement means 4 and carrier belt 3 are mounted on a generally conventioned form of structural framework support 18 (as shown schematically in Fig. 5), the conveyor 1 being provided adjacent its lower end l9 with a loading chute 20 and at its upper end 21 a discharge hopper 22 disposed for receiving material 2 discharged from the conveyor 1.

Fig. 5 shows a modified conveyor arrangement 23 wherein the conveying path is generally 'S'-shaped with the interengcaging runs 24, 25 of the carrier belt 3 and material engagement means 4, respectively, having concave and convex portions 26, 27 at the lower and upper end portions 28, 29, respectively, of the conveying path.
The carrier belt 3 has, moreover, ex~ended horizontal sections where assistance from the paddles is not required, continuir.g beyond the upper and lower ends 30, 31 of the bulk material engagement means 4. Thus this embodiment also illustrates how uphill or, as in this particuIar case as indicated by the arrows 32, downhill conveying can be effectively integrated into extended distance conveying between different levels, without the need for a number of separate conveyors and complex transfer arrangements therebetween.

In use of the conveyor 1 for uphill conveying, the bulk material engagement means 4 is driven with its paddles 10 projecting into the channel 7 defined by the carrier belt 3 in frictional engagement with the carrier belt 3 so as to entrain particulate material 2 within said channel 7 at ~he same time pulling along the carrier belt 3. In this way a separate friction drive for the carrier belt 3 may be dispensed with and drive efficiency ' maximised by use of a positive drive connection through a suitable sprocket engaging with the chain 8. Moreover by routeing the chains 8 o, the bulk material engagement means 4 generally in register with the base 30 of the - 5 trough 7 defined by the carrier belt 3 along the main part of the conveying path along which the material engagement means 4 interengages the belt 3, in the vertical plan i.e. with the same radius of curvature in the vertical plane (see Fig. 1), relative movement and slipping between the paddles 10 and the belt 3 is substantially avoided thereby avoiding wearing and damage thereto. It will also be appreciated that the plate edges 14, 15 of the paddles 10 will engage the carrier belt 3 particularly posi~ivel~
at sections of the conveying path which are curved in the vertical plane (upper end 21 in Fig. 1 and upper and lower ends 26, 27 in Fig. 5) so that drive transmission there-between will be particularly eEfective at those sections.
Whilst this will generally be more important for uphill conveying (Fig. 1) it is also desirable in downhill conveying (Fig. 5).

Also as may be seen from Fig. 1 the paddles 10 may be disposed at a relatively close spacing along the chains 8 thereby further maximising the effective material conveying capacity of the conveyor which is already quite favourable due to the shape of the paddles used.

As further shown in FigO l the carrier belt 3 flattens out as it approaches the return pulleys 5, the belt guide rollers 5 being suitably configured thereat. Where, as in the Fig. 5 embodiment, the conveyor includes extended horizontal carrier belt runs 35, it will be appreciated that the carrier belt 3 may have a more flattened configuration than in the inclined run sections.

It will also be appreciated in relation to the choice of connector means for the bulk material engagement means that where chains are used it is possible to use multiple ' 77~j 7i~ ;J7~7J,i , .~

drive sprocket arrangements at intermediate arrangements thereby avoiding the need for very large drive systems at the conveyor ends and high tension in the connector means to transmit drive along the full length of the connector means.

Conveniently the paddles 10 are provided with deflectable and/or resiliently deformable panels 33 at their central upper edges 34.

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Claims

1. A conveyor (1) suitable for use in conveying bulk material (2) which conveyor comprises an endless belt (3) and an endless bulk material engagement means (4) characterised in that said bulk material engagement means (4) comprises elongate flexible connector means (8) mounting a plurality of spaced part paddles (10), said carrier belt (3) and endless connector means (8) being mounted for movement along a conveying path with said paddles (10) projecting substantially into the interior of a channel (7) defined by said carrier belt (3) at least along said conveying path, in close proximity to the sides (3a) and base of said channel (7) so as to engage bulk material (2) within said channel (7) in use of the conveyor (1) and transfer drive forces between said connector means (8) and said bulk material (2) during uphill or downhill conveying of said bulk material, (2) said paddles (10) having a shape, at least at their distal ends (14), corresponding generally to the cross-sectional shape of said channel (7) and with said connector means (8) and said belt (3) following a substantially identical path in a vertical plane along the conveying path where said belt (3) and engagement means (4) interengage, whereby movement of said paddles (10) and said belt (3) therealong is maintained in substantial synchronism.

2. A conveyor as claimed in claim 1 wherein said elongate flexible connector means (8) comprises at least one of an endless chain, an endless cable, and an endless belt.

3. A conveyor as claimed in claim 1 or claim 2 wherein there are provided at least two said elongate flexible connector means (8, 9) generally parallel to and opposite each other.

4. A conveyor as claimed in any one of claims 1 to 3 wherein said paddles (10) are formed and arranged so as to define, together with the channel defined by the carrier belt (3), a generally scoop shaped receptacles, (13), each said paddle (10) forming a generally upright generally transverse wall curving round at opposite sides towards the conveying direction of said conveyor.

5. A conveyor as claimed in any one of claims 1 to 4 wherein said paddles (10) are formed and arranged to have resiliently deformable edge seals (15) formed and arranged for engagement with the belt (3) so as to minimise escape of bulk material (2) therebetween and to maximise drive transmission therebetween.

6. A conveyor as claimed in any one of claims 1 to 5 wherein said paddles (10) are provided with resiliently deformable and/or deflectable central portions (33) at their upper edges (34) to allow passage of projecting bulk material elements thereby to avoid jamming of and/or damage to the conveyor.

7. A conveyor as claimed in any one of claims 3 and 4 to 6 when dependent on claim 3 wherein said paddles (10) have generally transversely outwardly projecting mounting wings (10a) formed and arranged so as to extend over and around the outside of the side walls (3a) of the channel (7) formed by the carrier belt (3), for securing of the paddles (10) to respective endless connector means (8).

8. A conveyor as claimed in any one of claims 1 to 7 wherein each said paddle (10) has a transverse cross-sectional shape corresponding substantially to that of the channel (7) defined by said carrier belt (3) and is formed and arranged substantially to occupy said channel (7) and to engage the belt (3) at the base and/or sides of said channel (7).

9. A conveyor as claimed in any one of claims 1 to 8 wherein said endless connector means (8) is formed and arranged for driven engagement with drive means (16).

10. A conveyor as claimed in any one of claims 1 to 9 wherein said carrier belt (3) is formed and arranged for driven engagement with drive means (5a).

11. A conveyor as claimed in any one of claims 1 to 10 wherein said carrier belt (3) and said bulk material engagement means (4) are disposed in a generally back-to-back arrangement so as to be guided towards and away from each other at the beginning and end of said conveying path, respectively.

12. A conveyor as claimed in any one of claims l to 11 wherein said engagement means (4) are provided only at an inclined section(s) of the carrier belt (3).

13. A conveyor as claimed in any one of claims 1 to 11 which conveyor (1) includes a generally horizontal section (35), which section is provided with at least one said bulk material engagement means (4) for transmitting drive to the carrier belt (3) in said section directly and/or through bulk material (2) loaded thereon in use of the conveyor (1).

14. A conveyor (1) as claimed in any one of claims 1 to 13 which has at least one section inclined at an angle of at least 70° relative to the horizontal.

15. A conveyor as claimed in any one of claims 1 to 14 wherein said engagement means (4) is formed and arranged to allow top-loading of the bulk material (2) by dropping the material (2) into the carrier belt (3) through the engagement means (4) between successive paddles (10) in use of the conveyor (1).

16. A conveyor as claimed in any one of claims 1 to 14 wherein is provided a chute means (20) formed and arranged for side loading of bulk material (2) between the paddles into the carrier belt (3) in use of the conveyor (1).

17. A conveyor as claimed in any one of claim 1 to 14 which conveyor includes a generally horizontally extending section (35) upstream of the engagement means (4) for allowing end loading of the bulk material (2) thereonto in use of the conveyor (1).

18. A conveyor as claimed in any one of claims 1 to 17 wherein is provided a supporting framework (18) for mounting said conveyor (1).