Field of invention

The present disclosure relates to a media lining for a feeding apparatus and a feeding apparatus for feeding material. More specifically, the present disclosure relates to a lining with a textured pattern provided at an upward facing contact face of a feeder plate.

Background art

A feeder can be understood as a small size conveyor that is capable of transporting bulk material. In certain scenarios the material source is isolated from an intended processing device and needs to be transited to the intended processing device like a crusher, either due to height difference or horizontal separation. In other situations, it is required to change conveying direction of the material flow, and/or distribution speed of the material. So, the purpose of a feeder is to guide or bridge the material by an intermediate transporter. There exist different kinds of feeder applications. They may be classified by driving mechanism that use a vibration source, such as vibration feeders. In vibration feeders, the bulk material moves under gravity and vibration on a tilt floor of the feeder. Feeders can also be vibration-free feeders, such as reciprocating feeders, in which the movement of the material relies on reciprocating movement of a material holding unit.

The feeder typically comprises a material holding unit. A material holding unit may be called a container that is open at the top, or a trough, having a surface layer usually being covered or coated by a polymer layer to resist wear. Using polymer layer helps reduce noise compared to noise otherwise arising from using metal, this is important when considering the health of the operator. A pan feeder is an example of a feeder, it includes a material holding unit having a pan floor as well as side walls extending along material flow direction. The material holding unit has an opening at its discharging end that serves as outlet or exit for the material flow. Usually it is arranged as downwardly tilt in the material flow direction. The material holding unit is braced by spring support and is equipped with a vibration generation unit for applying vibration on the material holding unit.

A weakness with the current feeder is that its floor is subject to heavy wear from the abrasive bulk material. Feed plates are required to be replaced frequently when they are apt to wear out, this leads to more maintenance and loss of operational time of a machine. Further there is still room for increasing the feed rate or feeding capacity of a feeder.

Summary of the Invention

The aim of the present disclosure is to overcome or at least reduce the above-mentioned problems.

Different from a screening media which has apertures thereon in order to separate particles into groups of desired sizes, a feeder is understood as a conveyor that transfers a material completely from a charging end to a discharging end, without dropping part of material particles. The floor of the material holding unit of a feeder is free of apertures that allow the material particles to pass through, the material particles move - driven by gravity or vibration - from a charging end to a discharging end without being screened or interrupted. Further, a feeder is capable of modulating the rate of the material flow.

It is an objective of the present disclosure to provide a media (medium) for feeding apparatus, the media shall have improved wear resistance character for applications with sliding or impacting wear caused by the continual abrasive granular material flowing over the media. Also, it is objective to increase material feeding capacity of a feeder, to enable high material flow speed (i.e. high flow rate). It is a further objective of the present disclosure to provide a feeding media which is durable and is easy and cost-effective to maintain.

The objectives are achieved by providing a feeding media (specifically called feed plate) that is configured to be installed in a feeding apparatus (or called feeder), wherein the feed plate is made of wear-resistant and noise-suppressing material, typically elastomeric material, and is provided with a layer of lining having texture or textured pattern on the contact face, the lining forms an integral part of the feed plate. The texture or textured pattern is configured as regular recesses and/or projections that have specifically designed dimensions on the contact face, providing uneven surface at an upward facing contact face. It is preferable that the recesses and/or projections are equally spaced from each other. When material to be transferred is moving on the contact face, fines are trapped, accumulated and get piled within the recesses or spacings between projections. This builds a self-protecting wear layer or bed on the contact face, thereby avoiding material particles’ direct contact with the part of the feed plate. The material particles are therefore sliding or rolling on some fine particles of the conveyed material, and not on the lining. The self- protecting bed is continuously replenished, rebuilt and enhanced by the material flow. In this way it may reduce the friction between the feed plate (such as rubber) and material particles, since the friction is larger than the friction between the material particles (usually having high hardness). In connection, it reduces wear to a feed plate in the portion of the recesses.

Also, it may help to reduce wear to the portion of the projections, because the recesses or spacing between the projections may capture particles slightly larger than the size of the recesses or spacing. These particles will protrude beyond the projections (refer to figure 4A) and may in turn result in fine particles to accumulate and cover the projections. These fine particles may protect the projections, by reducing wear to the projections.

The wear reduction effect occurs only when the size/dimension of recesses or projections or spacing between the projections is chosen properly. It is noted that the dimension of recesses or spacing between projections shall not be extremely small, otherwise it tends to prevent capturing fine particles to build a self-protecting wear-resistant layer. On the other hand, said dimension shall not be too large, otherwise, large area filled with fines particles tends to provide less bouncing support to the particles to be conveyed but tends to entrap or catch particles, thus reduces the flow speed.

The character of textured pattern in combination with applied vibration gives rise to a synergistic agitated effect to at least part of the material particulates. This will reduce the duration of friction movement between the feed plate and granular material.

Advantageously the wear reduction effect makes the feed plate more durable, i.e. the life cycle of the feed plate is extended. In addition, considering the fact that the feed plate shall be replaced in the event of wom-out, the feed plate of the present disclosure needs to be replaced much less frequently. Accordingly, there are fewer operational stops for inspection and troubleshooting, i.e. it is cost-effective in maintenance.

Feeding capacity is understood as the amount of material that is processed or delivered per time unit by a feeder, it corresponds to a desired feeding rate that material is fed at. The material shall be fed at a rate such that it is not detained, or not get accumulated and piled up in the container of a feeder. It is expected to achieve a high capacity of 170 to 2,040 tons per hour.

The inclination of the container floor may have impact on feeding capacity, however in many installations the inclination of a container floor is determined and fixed, because there is no good possibility or available space to change the tilting angle of the container - due to the structure limitation at upstream (such as a bin) and at downstream (such as a crusher), none of the upstream/ downstream structure can be moved without tremendous work. It is found that using a lining can contribute to the increase of flow speed. When the lining makes the material flow rate higher for the same power setting of the feeder, power setting can be reduced to spare some energy but most importantly reducing the loads on the motors results in having greater lifetime on bearings, motors, reducing risks of cracking etc.

According to a first aspect of the present invention there is provided a feeding media for a feeding apparatus. The media comprises a general planar body preferably made of elastomeric material, having a contact face over which a granular material is intended to move, and having a back-face opposite to the contact face. The body having a thickness defined between the contact face and the back face, where the body extends along a material flow direction from a first end to a second end. It is further configured to guide the movement of the granular material from the first end to the second end, where at least an area of the contact face is provided with textured pattern. Alternatively, the entire the contact face is provided with textured pattern.

Reference within this specification to a‘textured pattern’ encompass a profiled surface having regions of different height including raised and recessed parts. This term

encompasses texturing provided at a surface by any one or a combination of ridges, ribs, lumps, projections, protuberances, grooves, cavities, pimples or channels. This term also encompasses the pattern being a regular repeating pattern and not a random collection of raised or recessed regions so as to be generally consistent and uniform over the contact face.

Preferably the textured pattern comprising a plurality of recesses and/or projections arranged on the contact face. By the wording‘recess’ it is understood as an indentation or concave formation relative to the contact face, by the name‘projection’ it is understood as a knob or bulge or convex formation protruding relative to the contact face. Preferably have all the projections a uniform length in a plane transversal to the contact face such that the outer end of the projections results in a plane being parallel to the contact face. A media with such configuration is easy to manufacture.

Preferably, the planar body extends along the material flow direction and along a transverse direction perpendicular to the material flow direction continuously (for example, without apertures, without interruption), and the textured pattern is continuously arranged on the contact face. The planer body sufficiently transfers the materiel.

Preferably, the thickness of the planar body is in the range of 5 mm to 50 mm. The media shall have sufficient thickness to achieve the desired structural strength.

Preferably, the recesses, and/or projections, and/or the spacing between adjacent recesses or projections, are of substantially equal size. Preferably, a dimension of the recesses and/or a dimension of projections and/or a dimension of the spacing between adjacent recesses or projections in a plane parallel to the contact face is generally smaller than a diameter of the desired granular material, the purpose of this is to ensure that the recesses and/or projections and/or the spacing between adjacent recesses or projections do not disturb the flow of the granular material. The dimension in a plane parallel to the contact face may be meant to be length or width or diameter. The desired granular material may be understood as granular material having predefined particle size.

Preferably, the recesses, and/or projections, and/or the spacing between adjacent recesses or projections, extend in each dimension equal to or less than 4 mm, for example, in the range of 0 to 6 mm, preferably in the range of 0,5 mm to 4 mm.

Optionally, the depth of the pattern is substantially smaller than the thickness of the planar body. In particular, the depth of the recesses and projections may extend in a range of 5% to 50% of the thickness of the planar body.

Optionally, the recesses or projections are of substantially circular, square, cruciform, or rectangular shape in the cross section in a plane parallel to the contact face. The shape is not limited to those listed herein, other shape may be implemented such as other polygonal, or oval, the recesses or projections may vary in height direction such as in conical or tapered configuration.

Optionally, the recesses or projections arranged in neighbouring rows along material flow direction are in staggered or aligned arrangement. In staggered arrangement, the spacing between the projections has a reduced dimension in comparison to aligned arrangement.

In one embodiment, the recesses or projections are arranged on the material contact face in a form of lattice graph.

In one embodiment, the general planar body made of a first elastomeric material comprises a further support layer disposed directly underneath the back face, the further support layer is arranged to be bonded or attached to said planar body to form a composite structure. It is possible to reduce the thickness of the upper layer by using a support layer having greater hardness, this achieves a lighter and compact and cheaper product.

Preferably, the planar body comprises an aperture for receiving a bolt for fixing the media onto a support structure (or called frame) of the feeding apparatus. The aperture is configured for a bolt to pass through and adapted to receive a cover to protect the bolt from wear.

Preferably, the further support layer is made of a second elastomeric material, which second elastomeric material has a hardness that is greater than the hardness of the first elastomeric material of the general planar body, preferably the first elastomeric material is polymer having a hardness in the range of 40 to 70 Shore A.

According to a second aspect of the present invention there is provided a material holding unit for feeding granular material, comprising a passage extending from a charging end to a discharging end, over the passage the material can be guided from the charging end to the discharging end; wherein the material holding unit comprises on the surface of the passage, one or more pieces of media as described in any preceding embodiment. Enables a more resistant surface.

According to a third aspect of the present invention there is provided a feeding apparatus for feeding granular material, comprising a material holding unit as described in any preceding embodiment.

Other aspects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.

The present disclosure will now be explained in relation to the accompanying drawings in which,

Figure 1 shows an elevation view of a feeder according to one of the embodiments of the present disclosure;

Figure 2 shows a perspective view of a container 100 of figure 1;

Figure 3A is a perspective view of a feed plate according to one of the embodiments of the present disclosure;

Figure 3B is a perspective view of a feed plate according to one of the embodiments of the present disclosure;

Figure 4A is a magnified partial cross section of a feed plate, made along longitudinal direction A- A of figure 3;

Figure 4B shows an imaginary magnified partial cross section of a feed plate;

Fig. 5 shows a perspective view of a feed plate according to another embodiment of the present disclosure; Fig. 6 is a perspective view of a feed plate according to a further embodiment of the present disclosure;

Fig. 7 is a perspective view of a feed plate according to a further embodiment of the present disclosure;

Fig. 8 shows a perspective view of a feed plate coupling to a frame of a feeder.

Detailed description of preferred embodiment of the invention

The present disclosure will now be described with reference to the accompanying embodiments in relation to the drawings.

Figure 1 shows an elevation view of a feeder according to one of the embodiments of the present disclosure, the feeder 10 is suitable for feeding bulk material in mining industry, mineral processing, construction, metallurgy and recycling industries. The feeder includes a material transfer container 100 or simply called container, extending in longitudinal direction 107, from a charging end 105 to an opposite discharging end 106. In this whole text, longitudinal direction is understood as equivalent to a material flow direction, a transverse direction is meant normal to the longitudinal direction. The container includes a frame 101 pivotably mounted via a plurality of shafts/studs 108 on spring supports 104. Transverse shafts/studs 108 are spaced apart from each other and connected to a longitudinal support beam 103 of the frame 101, shafts/studs 108 are used as pivot supports for coupling the frame to the vertically-deformable spring supports 104 which are in turn mounted to base seats. One or more vibration generating motor 102, be it hydraulic or electrical driven, are attached to the frame 101 for applying vibration onto the frame 101.

The container floor of a feeder is to be arranged inclined downwardly from a charging end to a discharging end in use, this facilitates the material particles to move under gravity along the surface of the media. The inclination of the container floor may be adjustable between 0-12 degrees in some applications, this shall adapt to different materials of the feed plate, feeding capacities and installation requirements. However, too large inclination may lead to safety problem, or non-homogenous speeds of granular particles, by too large inclination, the material will start to flow by itself even when the feeder is not active. In one embodiment, the feeder is disposed preferably in inclination of about 8 degrees.

Figure 2 shows a perspective view of a container 100, it is a trough-like unit in which the discharging end 106 is open to permit material to discharge. The frame of the container comprises a number of longitudinal beam 103, transverse beams 205, and upright rib beams 206, where the frame forms a reinforced bracket which is configured to support a plurality of feed plates 201, 202, 204. The feed plates may be modular design, including bottom base plates 201, substantially upright- arranged side walls 202, and rear wall 204. These are secured over the frame 101, rear wall 204 at the charging end 105 and may be backward tilt facilitating receiving material falling down (also see figure 1).

Referring to Fig. 3A, a perspective view of a feed plate according to one of the

embodiments of the present disclosure is seen. The feed plate 201 includes a general planar body 300 made of rubber, having a contact face 304 and a back face 305, where the entire contact face 304 is provided with a textured pattern. The arrow 107 indicates a material flow direction.

Referring to Fig. 3B, a perspective view of a feed plate according to one of the

embodiments of the present disclosure is seen, wherein the feed plate 201 is constructed as double-layer structure. The surface layer 302 may be bonded to (for example by vulcanisation process) or attached together with the bottom layer 303 to form a composite structure, where the composite structure or the bottom layer is to be mounted on the frame 101. Optionally, the surface layer and the bottom layer may be attached together by thermal or chemical bonding (e.g., via an adhesive) or mechanical attachment such as by pins, bolts, rivets, screws and the like.

The surface layer 302 has a textured pattern on the surface to prevent wear. The bottom layer 303 is preferably reinforced with fabric which in addition is to strengthen the feed plate. It can also act as a wear-indicator owing to the colour of the fabric which gets exposed when the top layer gets worn. This will forewarn the operator about the wear of the feed plate, so that it can be replaced before greater damage is caused.

The textured pattern is formed from peaks and respective troughs that collectively define a repeating pattern. In the embodiments shown in figure 3A and figure 3B the texture or textured pattern is formed with recesses 301 imbedded onto the surface of the feed plate. The recesses 301 are substantially the same size and regularly or homogeneously distributed over the entire surface of the surface layer. They may be distributed in a lattice or matrix or grid graph form. The recesses 301 are in the form of cylindrical indentations, i.e. the recesses are of circular configuration in cross section in a plane parallel to the surface, with equal dimension along the entire height direction.

Figure 4A shows a magnified partial cross section of a feed plate, made along longitudinal direction A- A of figure 3. The recesses 301 are spaced from each other by distance D, where D represents the dimension of the media left between the neighbouring recesses along the longitudinal direction. H is the depth of recesses, which is in the range of about 1,5 to 2,5 mm. S is the dimension or diameter of a recess. The value chosen for both S and D may be approximately 1 mm. It is observed that the value of S is somewhat critical to have impact on the flow rate and feed capacity, i.e. proper setting of S may help speed up the movement of material particles. In principle S shall be assigned a value large enough such that it allows the media to trap fine particles to accumulate at the recesses or spacing between projections. To create a renewable wear surface, on the other hand, S shall not be too large so that the indentations would not unduly retard the flowing of material. This is because by too large value of S, the indentations will start to act like“potholes” in a road and have an adverse effect on the flow, e.g. particles get entrapped or caught-in, this may restrict the flow, this shall be avoided. As illustrated in figure 4A the recesses allow only a particle of limited size to get stuck/seized. The largest particle to get trapped is SI in diameter, thus a proper value of S helps prevent too large particle to get stuck/seized. Referring to figure 4B which shows an imaginary magnified partial cross section of a feed plate, which with too large S would otherwise be considered to allow big particle to reside. A big particle protruding out beyond the surface of the feed plate will tend to block the flow.

The above setting value for S applies to the longitudinal direction or transverse direction. The aim is to ensure a maximal size of recess in at least one dimension, that is not being exceeded, for instance in one direction in a plane parallel to the surface, such as in longitudinal direction or transverse direction. S is preferably chosen as not greater than 4 mm, as the diameter of particles to be fed to the feeder is typical in the range of 0-100 mm. It is therefore proposed that S is set to approximately 1 mm.

In the embodiment of figure 3B, the surface layer 302 and the bottom layer 303 may be made of different materials. The surface layer 302 is preferably made of rubber or polyurethane materials, which may have a thickness of about 5 mm. Some examples of commonly used rubber grades are SR, NBR and BR. For applications inducing high wear, it is recommended that the rubber has the hardness in the range of 40 to 70 shore A. The bottom layer 303 may be formed with material having greater hardness than surface layer 302, the bottom layer may have a thickness of about 3 mm. The bottom layer 303 may also be rubber reinforced with fabric to add strength to the feed plate. To reinforce, the fibres of the fabric are integrated in the rubber or polymeric material at the time of extrusion.

Reinforcement of the feed plate allows for decrease in the thickness of the feed plate making it lighter and easier to transport. The fabric used for reinforcement may be selected from a range of polyesters, polyamides, nylon or carbon fibres. The reinforcement of fibre must have the same characteristics of both warp and weft, that is the same e-module.

Alternatively, the feed plate may have more than one reinforcement layer included below the surface layer. The more the number of layers, the more is the reinforcement and the more is the strength of the feed plate.

The textured pattern may be moulded integrally with the feed plate, for example, formed by compression moulding. They may be created conveniently by pressing a woven mesh or other substrate into the rubber surface layer as part of the vulcanisation process. Once the mesh is removed, an imprinted pattern is formed corresponding to the shape profile of the woven mesh so as to define the peaks and troughs. The shape of the textured pattern at the surface of the top layer may be achieved by selecting the appropriate dimensions and cross-sectional shape profile of the warps and wefts of the imprinting mesh. Optionally, the rubber material may be placed in a designed mould which conform to the required texture pattern, subsequently perform the heating, pressing and cooling process to form the texture on the surface.

Referring to Fig. 5, it illustrates another embodiment of a feed plate, wherein the lining is not composed of recesses, but projections 501 of circular configuration in cross section in a plane parallel to the surface, with equal dimension along the entire height direction. The cross section is similar to figure 4A, the difference lies in that now the troughs are not formed by cylindrical indentations, but the spacings left between the cylindrical projections 501.

Fig. 6 illustrates a further embodiment of a feed plate, wherein the lining is composed of projections 601 which are of rectangular configuration in cross section in a plane parallel to the surface, with equal dimension along the entire height direction. The cross section is similar to figure 4 A, but the troughs are not formed by cylindrical indentations, but the spacings left between the rectangular projections 601.

Fig. 7 shows a further embodiment of a feed plate, wherein the lining is composed of projections 701 which are of cruciform configuration in cross section in a plane parallel to the surface, with equal dimension along the entire height direction.

In all above embodiments, the texture is of repeated pattern, the recesses 301 or projections 501, 601, 701 on neighbouring rows along the material flow direction 107 are in staggered arrangement. In general, in respect of the dimension of the recesses 301, and/or the dimension of projections 501, 601, 701, and/or the dimension of the spacing between the recesses 301 or projections 501, 601, 701. The patterns shall be designed in a manner such that the entrapping of a particle with a diameter of larger than 4 mm is prevented. For instance, this can be implemented as: in at least one direction in a plane parallel to the surface, the recesses 301, the spacing between projections 501, 601, 701 does not exceed 4 mm. Figure 8 is a perspective view of a feed plate coupling to a frame of a feeder. A feed plate 201 and a base plate 802 of a frame may be punched with aligned apertures at different locations. The feed plate 201 is releasably attached /secured to base plate 802 of the frame with the help of bolt and nut or screw arrangement passing through the apertures 801. Once an individual feed plate is worn-out, it is removed by loosing the bolt/nut connection and replace it by a new one.