CA2170150C - Dry grader for very fine coal - Google Patents

Abstract

A highly efficient dry sorter (1) for continuous operation has a conveyor be lt cover (4) with longitudinal grooves, with the corresponding conveyor surface arranged obliquely in such a way that the coarser coal runs off over the grooves while the fine st coal or substance remains in them. It is thus possible for the finest coal to be extracted from the top while the coarser granules are removed by the lower longitudinal side. T he belt conveyor (2) is given the necessary permanent tilt by the fact that to the underside (16) of the conveyor belt cover (4) are allocated edge supporting strips (17,19) designed to correspond to supporting rollers (22,23) arranged at a distance along the bearing frame (3). These supporting rollers (22,23) are supplemented by pressure rollers permitting the even securing of the edge region on both the upper and the lower longitudinal sid e (20). Dry fine coal is sorted with a high throughput rate and can be further processed without any drying, thus giving rise to the minimum outsize quantities, as tests have shown.

Description

Dry Sorter for Very Fine Coal The invention relates to an installation for separating forest granular materials, in particular finest coal, with an angled belt path supported in a support frame, whose conveyor belt cover is equipped with longitudinal grooves extending in the longitudinal direction of the belt conveyor, with a feed which feeds at the feed-side deflection roller from the elevated longitudinal side, a coal discharge provided at the front of the discharge-side deflection roller, and a rough material discharge provided at the lower longitudinal side of the conveyor belt cover. The invention also relates to a process for drying and classifying finest material, in particular finest coal, in which the finest coal is fed from the top edge onto the endless and angled conveyor belt cover of a belt conveyor, whereby the finest coal granules are retained in the grooves of the conveyor belt cover and are discharged at the top of the belt conveyor, while the rough coal granules run off via the angled conveyor belt cover and are removed via the lower longitudinal side of the conveyor belt cover.
In the classic method of classifying materials with different granule sizes, the mixture is passed over a screen provided with a suitable perforation and is then separated into overflow granules and pass-through granules. It is also a known practice to vibrate the screening surface in order to accelerate the separation of the granule classes in this manner.
Such a screening classification is so far possible up to a granule size of 10 mm and below, but becomes more difficult and less accurate the higher the finest granule content is. In particular in the case of roller cutting machines and continuous miners, the finest granule content is very high, whereas the rubbish content in this finest granule content is very low.
Since the processing costs for finest coal are very high and the finest coal, which is then moist, must then also be dried, attempts have been made to classify this finest coal by dry method. GB-PS 7 225 from 1914 describes an installation for classifying finest granule materials - in particular, coal - in which a belt conveyor is equipped with a groove profile conveyor belt. Due to the angled belt conveyor, the fed fine materials remain stuck in the grooves and are separated from the rough material which falls off the sides of the conveyor across the grooves. When viewed over the length of the belt conveyor, support rollers are arranged transversely to the running direction, which, due to their mufti-edged construction, generate a vibration effect in order to compensate for the disadvantage caused by the relatively low incline of the conveyor. This results in an inaccurate rough particulate containing a relatively high finest granule content. If the belt conveyor were to be placed at a greater angle, the belt would slip even with a relatively high preload, whereby this effect would even be magnified by the vibration rollers. This would result in the frequent standstill and readjustment of the classifier.
The invention is therefore based on the objective of creating an installation and a process ensuring a frictionless and efficient continuous operation of a dry classifier.

According to the invention, there is provided an apparatus for separating fine-grained substances, particularly fine coal, comprising an endless conveyor belt having a topside and an underside, a support structure for holding the conveyor belt in an angled position, a cover layer on the topside of the conveyor belt, longitudinal grooves extending lengthwise along the conveyor belt, a feed side drivable deflection roller and a discharge side drivable deflection roller for moving the belt, supporting rollers at spaced intervals, at least one supporting strip on the underside of the conveyor belt for running on the supporting rollers, pressure rollers positioned above the supporting strip for maintaining a position of the conveyor belt, a feed for feeding substances onto the conveyor belt at the topside, a fine particle discharger adjacent the discharge side drivable deflection roller, and a coarse material discharger adjacent the conveyor belt.
Such an installation advantageously makes it possible to provide different angles for the belt conveyor, whereby in each case, independent from the selected angle, the conveyor belt cover is set by the supporting strip and the associated supporting rollers and pressure rollers in such a way that the respective desired separation effect is safely attained. The separation effect is also attained in particular due to the fact that because of the selected and adjustable angle, preferably 35°, no vibration rollers or similar devices are needed. The supporting strips are hereby arranged on the underside of the conveyor belt cover, so that they do not adversely affect the classification result, whereby it is also advantageous that the supporting rollers are also positioned between the carrying run and the returning run, so that they, as such, do not cause any adverse effect, but also cannot be affected adversely by the charged material. Only the pressure rollers, which ensure an even support through the supporting rollers, are provided on the top side in relation to the carrying run, whereby they can be secured by means of appropriate protection devices. In addition, only a few of these pressure rollers are required over the length of the belt, so that they, as such, also do not represent a hindrance to the operation of the belt conveyor. The advantage is that such an installation creates a dry classifier which is optimally suited for continuous operation and which enables constant, dry classification, so that the finest material can already be separated prior to feeding the fine coal to the jigging machine. The expensive drying required in the past is not longer necessary.
A useful embodiment of the invention provides that the conveyor belt cover is equipped on both sides with a supporting strip which is associated at a distance also with supporting rollers positioned at the lower longitudinal side. This supports the conveyor belt cover on both sides, whereby the lower supporting rollers ensure that the conveyor belt cover or the conveyor belt run does not move upwards. Rather, it is precisely set by the bilateral arrangement of the supporting strip and the supporting rollers. However, in the case of the supporting rollers associated with the lower longitudinal side, the pressure rollers are no longer necessary, since here a folding-up or creeping-up from the area of the supporting rollers need no longer be feared.
Another useful embodiment provides that the returning run of the belt conveyor is associated at a distance with supporting rollers and pressure rollers, so that even the carrying run is held precisely, thus safely preventing slipping on the one hand, and also a moving-up of the belt in the angled position.

27026-38 ca o2moiso Zooo-ii-09 A useful embodiment concerning the supporting strip provides that the underside of the conveyor belt cover is glued to the supporting strip which is constructed as a rectangular rubber or plastic profile. This construction has the advantage that profiles which correspond to the respective application, i.e., to the necessary respective length of the belt conveyor, can be inserted. In the case of a correspondingly wide profile, the necessary pressure can also be easily absorbed by the supporting strip, thus ensuring the necessary securing of the conveyor belt cover.
In order to ensure that the conveyor belt cover is also set and supported correctly via the supporting rollers, the invention provides that the plastic profile has a width corresponding to the width of the supporting rollers, whereby, as a rule, the supporting rollers are somewhat wider than the supporting strips. In addition to the rectangular construction, other embodiments of the supporting strip would also be conceivable, whereby, according to one useful possibility, the plastic profile has a triangular shape, whereby it forms a right-angle triangle which rests with the angle legs enclosing the right angle against the underside or extends parallel to the belt, and whereby the supporting rollers are constructed correspondingly. This design makes it possible to provide the necessary settings together with the pressure rollers. Depending on the positioning of the triangle, it is now even possible to completely eliminate the pressure rollers.
In particular, the pressure rollers can be completely eliminated if the plastic profile is shaped so as to correspond to the supporting rollers which are constructed as diabolo rollers, or if rollers and profiles have reversed shapes. This construction of the supporting rollers or supporting strips also provides the necessary settings in the direction of the creeping of the conveyor belt, which is now not only prevented from moving downward in relation to the angled position, but also from lifting from the supporting rollers. Pressure rollers are thereby no longer necessary.
It has been pointed out before that the conveyor belt cover and the plastic profile are constructed as a structural unit. But it would also be conceivable that they are integrated into the conveyor belt cover so that they can be produced and shaped simultaneously with the conveyor belt during its manufacture.
The necessary processing result is attained, as described above, by the longitudinal grooves, whereby it is useful that these longitudinal grooves be associated with the conveyor belt cover by providing the conveyor belt cover with a belt surface with a glued-on groove profile web. This has the advantage, similar to the case of the glued-on supporting strips, that standard conveyor belts can be used which are complemented with the groove profile web or also the supporting strips. This also makes it possible to attain the exact construction of the grooves and bridges more optimally, since a suitable rubber web can be used.
The exact setting of the belt conveyor or conveyor belt cover requires, as described above, both the positioning of the supporting strips or supporting rollers, and also that of the pressure rollers. In order to ensure both a correct and quiet guidance of the pressure rollers 27026-38 ca o2l~oiso Zooo-ii-09 here, the invention provides that the conveyor belt cover is provided at the edge and on both sides with non-grooved roll-off surfaces. In this way, the pressure rollers are rolling off in a precisely guided manner on this roll-off surface or the bilateral roll-off surfaces in order to ensure the exact setting of the conveyor belt cover.
According to the invention at hand, the conveyor belt cover with its groove profile web has longitudinally extending grooves and lands, whereby the lands are equipped with angled sides and rounded free edges. The groove profile track has identically constructed grooves and lands over the entire width in order to achieve a constant separating result.
During the transport over the length of the belt conveyor, the rougher granules are able to separate in time from the fine or finest coal over the angled sides and rounded edges, and are able to escape over the lower longitudinal side. Only the actually desired finest granules adhere inside the grooves and are safely discharged at the top, whereby experiments have shown that practically no outsize granules, or less than 10 % outsize granules, remain in the forest coal.
An optimum separation can be achieved in particular in that the conveyor belt cover is equipped with lands with an approximately 50 % smaller width at the free end than on the connection side, which has the additional advantage that the lands retain sufficient setting on the web or in the groove profile web.
The belt conveyor is an endless conveyor, whereby the conveyor belt cover is guided over two deflection rollers arranged at the ends, of which one is equipped with a drive. In order to prevent or mvaimize flexing inside the supporting strip or the supporting strips, the invention provides that the conveyor belt cover is guided in the area of the deflection rollers, for which purpose these are provided on the edges with recesses holding the supporting strips. In this way, the conveyor belt cover runs on the surfaces which project further, while the supporting strips engage somewhat deeper into the deflection rollers and are also su~ciently supported there. This largely counteracts flexing, whereby the supporting strips are possibly also divided into sections in order to reduce the flexing even further, in particular in the case of deflection rollers with a small diameter.
A division of the supporting strips into individual sections may, however, result in problems for the supporting strips and contribute to higher wear. To avoid this while facilitating the deflection of the supporting strips or conveyor belt cover, the invention provides that the conveyor belt cover is equipped with supporting strips which are equipped with spaced-apart cut-outs which taper off in arc-shape towards the center of the conveyor belt cover and leave a reinforcing land. This preserves a continuous support surface for the supporting rollers, while the supporting strips are able to move apart or together in the remaining area when running around the deflection roller. This creates an optimum design.
In order to be able to produce conveyor belt covers with practically any desired width, and to do this at reasonable cost, the invention provides that the conveyor belt cover is equipped with a groove profile web composed of several interconnected partial webs. This 27026-38 ca o2l~oiso Zooo-ii-09 creates double-width lands in the contact area of the individual groove profile webs, which, however, does not adversely affect the effectiveness of the entire conveyor belt cover or the belt conveyor in its entirety. .
In order to even out the tension of the conveyor belt cover or to ensure an adequate transmission of the drive forces, the conveyor belt cover can be tightened via the deflection rollers which are positioned adjustably in the support frame. This makes it possible to increase, e.g., the preload during longer operation, or the preload can also be reduced if the load on the conveyor belt cover is small.
It has already been pointed out above that it can be useful to adapt the tilt or angled position of the belt conveyor to the respective circumstances. In order to be able to accomplish this in a simple and useful manner, the invention provides that the conveyor belt cover with the support parts, as well as the deflection rollers and drives, is associated with a support bracket which is part of the support frame and is positioned with the lower longitudinal side via pivot joints in the support frame, and is held at the upper longitudinal side by adjustment devices. In this way, the tilt of the entire part of the belt conveyor can be adjusted evenly without risking that the conveyor belt cover receives or has a different tilt at some points. The entire support bracket is simply swiveled more or less around the pivot joint, and its tilt is adjusted.
It is useful that the adjusting devices are constructed as adjusting spindles, whereby the adjusting spindles can be associated with motors in order to ensure a uniform adjustment for several, longitudinally distributed, spindles in this manner or to facilitate the adjustment.
Naturally, it is also conceivable that the adjusting devices be operated manually.
As has already been mentioned repeatedly, the rough granules pass over the individual lands and are discharged via the lower longitudinal side of the conveyor belt cover, i.e., onto a rough granule conveyor extending there in the longitudinal direction of the belt conveyor.
In order to be able to safely catch the rough granules rolling off, it is hereby provided that the lower longitudinal side of the conveyor belt cover is associated with an adjustable guide rail. These rough granules, in a manner of speaking, are guided by this guide rail into the rough granule conveyor or are guided in such a way that they do not move past the rough granule conveyor.
In the long run, perfect operation of such a classifier is only possible if the forest granules are also discharged at the return. This is accomplished in that the return run of the belt conveyor is associated with cleaning brushes which engage with the groove profile web.
These cleaning brushes are rotated as a result of being driven by the belt conveyor or are provided with corresponding drives, and ensure that the individual grooves are always kept clean after the belt has passed the return, which is usually provided with a drive.

27026-38 ca o2l~oiso Zooo-ii-09 A uniform cleaning of the individual grooves according to the invention is also improved, in that the cleaning brushes are arranged on a shaft which is provided with a drive. Several cleaning brushes can hereby be arranged on one shaft and can be driven or braked by the shaft; and it is also conceivable that several shafts with cleaning brushes can be provided in order to ensure safe cleaning in this way. The shaft drive in this case can be switched so that the shaft, and therefore also the cleaning brushes, run slower than the belt conveyor, thus improving the cleaning effect even more.
Instead of the supporting strips and mechanical support device, the invention also permits a solution according to which the conveyor belt cover is equipped on the underside at the edge with permanent magnets arranged so as to correspond with the coils associated with the carrying belt. This linear motor drive can be designed here in such a way that it only supports the conveyor belt cover. But it is also conceivable that all drive forces are generated via this linear motor drive, so that it would fulfill two functions.
Since both the permanent magnets and the coils are located in the dust-free area, this makes a continuous operation of this kind easily possible.
A process for the dry classification of finest material provides, according to the invention at hand, that the conveyor belt cover is supported so as to roll at the edge of the upper longitudinal side during the circulation, that the circulation speed of the conveyor belt cover andlor the charged amount and/or the belt width and belt length and/or the angled position of the conveyor belt cover is varied in accordance with the granule structure of the charged material, and that the conveyor belt cover is supported and guided uniformly, thus resulting in a quiet run, from the underside over the entire length of the belt conveyor.
Such a process results in an execution which can be adapted exactly to the respective charged material without requiring a special design. Rather, the respective variation can be implemented by the respective examination of the charged material, so that an increasingly more uniform classification result can be achieved. But a continuous operation is made possible by this process in particular, because the belt conveyor is kept in the respective, necessary angled position, so that in particular the simplest possible adjustment can be performed, namely the change in the tilt of the belt conveyor.
According to a useful further development, the invention provides that the circulation speed and/or the feed volume and/or the tilt of the conveyor belt cover and/or the belt width and belt length is varied in accordance with the difference in the specific weight of the charged material, so that such a classifier can finally also be used for sorting. Because of this, the versatility of the process and the installation according to the invention are enormously high, and it can be used both for coal and in other areas.
For optimum execution of the process according to the invention, i.e., the exact setting of the belt conveyor or the conveyor belt cover, it is provided that the latter be supported on the upper and lower longitudinal sides so as to be rolling. As has already been explained above, the rolling setting both defines and changes the necessary tilt of the belt conveyor, and prevents in the case of an uneven load, an upward slipping or upward creeping of the conveyor at the lower longitudinal side.
The invention is characterized in particular in that this installation, i. e.
, the dry classifier, eliminates the former high expenditure of processing the forest material in the jigging machines of a processing plant. The finest material is already separated prior to being introduced into the jigging machine, and thus need not be subjected to the expensive drying. The processing result can be greatly influenced by the possibility of a speed change and adjustment of the tilt and in the process in particular, can also be kept uniform while considering the respective charged material. The dry classifier is based essentially on a belt conveyor, which, however, has a special design, yet still represents in principle a known technology. Its advantage is that it can process large amounts of forest coal or forest material. The dry classifier is also resistant to malfunction, in particular if the grooves are continuously kept free with cleaning brushes.
Other details and advantages of the object of the invention are derived from the following description of the related drawings showing a preferred exemplary embodiment with the details and parts required for this purpose. In the drawing:
Figure shows a simplified illustration of a frontal view 1 of the dry classifier, Figure shows a section through the conveyor belt cover with 2 the supporting strips on the edges, Figure shows a special design of the supporting strips, Figure shows a section through the groove profile web, Figure shows an enlarged portrayal of the edge area of a conveyor belt cover with supporting strip, Figure shows a detail view of the support bracket holding 6 the essential parts of the belt conveyor, Figure shows the cleaning brushes associated with the return 7 run, Figure shows a lateral view of the suspension of the cleaning 8 brushes, Figure shows a longitudinal section through the deflection 9 roller which is not driven, Figure shows a section through the deflection roller which is equipped with a drive.

Figure 1 shows the entire installation of the dry classifier 1, whose core part is the tilted belt conveyor 2. This belt conveyor 2 is arranged in a support frame 3 which is provided with several parts for supporting and guiding the conveyor belt cover 4.
The finest material is transferred to the conveyor belt cover 4 via the feed 6 which is associated with the upper part of the conveyor belt cover 4. This feed area is constructed as a vibration screen 7. The rough material passes over the conveyor belt cover 4 and is discharged via the lateral rough material discharge 8 and transferred to the rough granule conveyor 9. Precise guidance is provided by the guide rail 10 which can be adjusted in its tilt and its distance to the rough material discharge 8. An overflow guide 11 is provided on the opposing side of the rough material discharge 8, since the rough granule overflow from the vibration screen 7 is, after all, also supposed to be picked up by the rough granule conveyor.
The belt conveyor 2 has an endless, guided conveyor belt cover 4, whereby the classification is performed via the correspondingly designed carrying run 14, while the return run 15 is used to return the conveyor belt cover 4.
The underside 16 of the carrying run 14 or the top side of the return run 15 are provided with supporting strips 17, i.e., at the upper longitudinal side 18, and, additionally, there are supporting strips 19 at the lower longitudinal side 20. These supporting strips 17, 19 are, in particular, glued to the underside 16. The supporting strips 17, 19 support or hold the conveyor belt cover 4, so that there is always a uniform belt surface 21 available for holding or classifying the charged material. The support frame 3 is hereby associated with brackets 22, 23 which roll off the supporting strips 17 and 19 and which ensure that the conveyor belt cover 4 is both unable to slip in the direction of the lower longitudinal side 20, or can be pushed up in the direction of the upper longitudinal side 18, especially in the case of an uneven load. The supporting rollers 22, 23 hereby ensure that the conveyor belt cover 4 remains in the respective, exactly specified position, even in the case of an extreme tilt of the belt conveyor 2. This applies both for the carrying run 14 and the return run i5, which is also associated with supporting rollers 22, 23' .
In order to avoid a bending up or running up and escaping of the edge of the conveyor belt cover 4, pressure rollers 25 which run below covers 24 are provided. Figure 1 here clarifies that additional pressure rollers 25' roll off the underside of the return run 15.
Figure 1 clarifies that the belt surface 21 of the conveyor belt cover 4, which will be specified further in the following figures, can extend at the specified tilt (15 - 45 °, preferably 35 °). Such a belt surface 26 makes it possible that the finest material remains in the grooves shown in Figure 2, while the rough granules roll past the respective lands and, as already mentioned, leave the actual belt conveyor 2 or dry classifier 1 at the lower longitudinal side 20. The tilt of the belt conveyor 2 can be adjusted since the entire belt conveyor 2, in a manner of speaking, is associated with a support bracket 29, as shown in Figure 6. This support carrier, which, in a manner of speaking, holds the conveyor belt cover 4 and the associated parts of the support frame 3 in order to be able to operate the belt conveyor 2 accordingly, can be swiveled about pivot joint 30 which is located at the lower longitudinal side 20. The swiveling is hereby accomplished via an adjusting device 31 which, as is shown in Figure 1 and Figure 6, can be lifted via a spindle or similar device, whereby this spindle can also be equipped with a drive, thus easily enabling motorized adjustment. It is useful that two or more such adjusting devices 31 are arranged over the longitudinal side of the belt conveyor 2.

Figure 1 shows a section of a conveyor belt cover 4. It is hereby clear that, according to Figure 2, the rubber profiles 33 which function as supporting strips 17 or 19 are positioned on the underside 16. These rubber profiles 33 reach up to the belt edge 34 or form an even edge together with the latter, both at the upper longitudinal side 18 and the lower longitudinal side 20.
According to Figure 3, the supporting strip 17, 19 or the rubber profile 33 may also have a triangular shape, whereby the straight sides 35 of the angle enclosing the right angle are used, for example, to form a connection with the conveyor belt cover 4, or are part of forming the belt edge 34. The third side 36 of the triangle functions as a roll-off surface for the supporting roller 23.
Figure 2 and Figure 3 show that, contrary to the rubber profiles 33, the actual conveyor belt cover 4 has a belt 37 which is also equipped with a weave or is provided with similar reinforcements.
Figure 2 as well as Figures 4 and 5 clarify that a groove profile web 40 is glued onto the actual belt of the belt conveyor 2, which then forms the conveyor belt cover 4. This groove profile web 40 has on both longitudinal sides 18, 20 roll-off surfaces 41 for the pressure rollers 25. This has already been pointed out in the explanation of Figure 1.
Between these roll-off surfaces 41 are uniformly constructed grooves 42, 44 and lands 43, 45, whereby the lands 43, 45 are provided with angled sides 46, 47 and rectangular grooves, while the free edges 49, 50 of the lands 43, 45 are rounded. This is especially clear in Figures 4 and 5.
The special shape of lands 43, 45 results in a smaller width in the area of the free ends 51 of the lands 43 and 45, while on the connection side 48 a corresponding widening of the land 43 and 45 is achieved. This results in an adequate stiffness of these lands 43, 45, in spite of the relatively deep grooves 42, 44.
Figure 5 clarifies how the flexing in the area of the deflection rollers, which will be explained below, is reduced, for which purpose the individual supporting strips 17, 19 are provided with spaced-apart cutouts 54. These cutouts 54 are hereby constructed so that a support land 55 remains towards the center of the conveyor belt cover 4. For this purpose, the cutouts 54 extend in arc-shape towards the center of the conveyor belt cover 4 and taper off at a distance to the support edge of the supporting strip 17, 19. This results in a continuous roll-off track for the rolling-off supporting rollers 22 or 23, so that wear can be kept remarkably low.
Seen over the width of such a conveyor belt cover 4, it is useful that several groove profile webs 40 or corresponding partial webs 56, 57 are arranged, so that it is also possible to adapt the width of the conveyor belt cover 4 according to the requirements.
Partial webs 56, 57 each abut each other with one land, thus resulting in a kind of double land 58.

Figure 6 has been mentioned already. In addition, it should be pointed out that for a smooth, uniform guidance, even over longer belt conveyors 2, reinforcing rollers 59 and 60 have been provided once for the carrying run 14 and once for the return run 15. In relation to the reinforcing roller 59, a smaller width is provided in each case, so that the supporting strips 17, 19 constructed at the sides can be taken into account. Also shown here is a pressure roller 25 and the cover 24 associated with it. 61 designates a support part, which stands for the reinforcing rollers 59, 60 and the support rollers 22, 23, as well as the pressure rollers 25. This totality of supporting parts 61 ensures the precise setting of the conveyor belt cover 4 over the length of the belt conveyor 2.
Figure 7 shows the bottom part of the belt conveyor 2, where the cleaning brushes 64, 65 acting on the returning run in order to clean the groove profile web 40 are shown.
The cleaning brushes 64[sic], 65 shown here are positioned on a common shaft 66 and thus rotate uniformly or, depending on the construction, also at a different speed, whereby the latter depends on the speed of the conveyor belt cover 4. It is however also conceivable that the shaft 66 is braked, so that the bristles 67 of the cleaning brushes 64, 65 perform a specific cleaning action. But usually an unbraked design is adequate.
According to Figure 8, two or even three cleaning brushes 64, 64' are positioned as a compact cleaning unit, whereby, e.g., additional cleaning brushes can be positioned on the center shaft 66, resulting in a compact cleaning unit which is practically and safely connected to the support frame 3.
Figures 9 and 10 show the deflection roller 68 without drive, and the deflection roller 69 with drive 70, whereby both are provided on the edge with recesses 71, 72 on which the supporting strips 17, 19, which are not shown here, support themselves when turning about the deflection rollers 68, 69.
The deflection rollers 68, 69 are provided with a coating 73 which is supposed to promote a uniform transmission of the drive forces, especiaily in the area of the deflection roll 69 shown in Figure 10.
All mentioned characteristics, including those which can be derived only from the drawings, are considered to be essential to the invention both by themselves and in combination.

Claims (22)

CLAIMS:

1. Apparatus for separating fine-grained substances, particularly fine coal, comprising an endless conveyor belt having a topside and an underside, a support structure for holding the conveyor belt in an angled position, a cover layer on the topside of the conveyor belt, longitudinal grooves extending lengthwise along the conveyor belt, a feed side drivable deflection roller and a discharge side drivable deflection roller for moving the belt, supporting rollers at spaced intervals, at least one supporting strip on the underside of the conveyor belt for running on the supporting rollers, pressure rollers positioned above the supporting strip for maintaining a position of the conveyor belt, a feed for feeding substances onto the conveyor belt at the topside, a fine particle discharger adjacent the discharge side drivable deflection roller, and a coarse material discharger adjacent the conveyor belt.

2. The apparatus of claim 1, wherein there are plural supporting strips protruding from the underside at upper and lower edges of the conveyor belt, the supporting strips being positioned for placement on the supporting rollers.

3. The apparatus of claim 1, wherein the conveyor belt comprises an upper carrying section and a lower return section, and wherein a distance between the upper and lower sections is defined by the drivable rollers and the supporting rollers.

4. The apparatus of claim 1, wherein the supporting strip is of rubber or plastic material and wherein the supporting strip is attached to the underside of the conveyor belt.

5. The apparatus of claim 4, wherein the supporting strip has a rectangular profile.

6. The apparatus of claim 4, wherein the supporting strip has a width corresponding to a width of the supporting rollers.

7. The apparatus of claim 4, wherein the supporting strip has a profile of a right-angled triangle, wherein a side along the right angle is parallel to the underside of the belt, and wherein the supporting .rollers are complementary to the profile of the supporting strip.

8. The apparatus of claim 4, wherein the supporting strip and the supporting rollers have complementary profiles.

9. The apparatus of claim 1, wherein the conveyor belt, the cover layer and the supporting strip are an integral unit.

10. The apparatus of claim 1, wherein the cover layer comprises a grooved profile web attached to the belt topside.

11. The apparatus of claim 8, wherein the cover layer has non-grooved roll-off surfaces at upper and lower edges.

12. The apparatus of claim 10, wherein the grooved profile web has longitudinally extending grooves and ridges, and wherein the ridges have angled sides and rounded edges.

13. The apparatus of claim 12, wherein the ridges have about 50% smaller width at a peak end than at a base end of the belt.

14. The apparatus of claim 12, wherein the drivable deflection rollers have grooves for seating the supporting strips of the conveyor belt.

15. The apparatus of claim 1, wherein the supporting strip has spaced recesses tapering off in an arc-shape.

16. The apparatus of claim 10, wherein the grooved profile web further comprises plural interconnected partial webs.

17. The apparatus of claim 1, wherein the drivable deflection rollers have adjustable positions in the support structure for tightening the conveyor belt.

18. The apparatus of claim 1, wherein the support structure further comprises support brackets at a lower end for holding the drivable deflection rollers, and wherein the support structure further comprises swivel joints and swivel adjusting devices at an upper end of the support structure.

19. The apparatus of claim 18, wherein the adjusting devices are adjusting spindles.

20. The apparatus of claim 1, further comprising an adjustable guide rail positioned adjacent a lower edge of the conveyor belt cover layer.

21. The apparatus of claim 3, further comprising cleaning brushes engageable with the grooves at the lower return section.

22. The apparatus of claim 21, further comprising a rotatably driven shaft for mounting the cleaning brushes.