GB2564605A

GB2564605A - Twin roller crusher

Info

Publication number: GB2564605A
Application number: GB1816527.4A
Authority: GB
Inventors: Dick Matthias
Original assignee: Crush and Size Technology & Cokg GmbH; Crush Size Tech & Co KG GmbH
Current assignee: Crush and Size Technology & Cokg GmbH; Crush Size Tech & Co KG GmbH
Priority date: 2016-03-22
Filing date: 2017-03-08
Publication date: 2019-01-16
Also published as: DE112017001451A5; GB201816527D0; WO2017162230A1; DE202016101549U1

Abstract

In order to improve a twin roller crusher having rollers (1, 2) which are rotatably mounted in a crusher housing, are motor-driven in opposite directions and the centre longitudinal axes of which are directed parallel to one another, wherein the casing of the rollers (1, 2) has arranged thereon crushing teeth (4) which project beyond the casing surfaces (3), wherein a small gap is formed in each case between the free end of each tooth (4) of one roller (1, 2) and the casing (3), opposite thereto, of the other roller (1, 2), wherein the crushing teeth (4) are arranged in rows in the circumferential direction of the rollers (1, 2) and each row of crushing teeth (4) of the first roller (1) is axially adjacent to a row of crushing teeth of the second roller (2), in terms of the comminuting ratio of said crusher, that is to say to make available a comminuting ratio of >1:4, which crusher dispenses with synchronization of the rotational movement of the rollers and can thereby be produced cost-effectively and simply and has a long service life, crushing tooth rows of different tooth height are arranged on the casing (3) of the roller (1, 2), wherein the distance between the casing surfaces (3) of the rollers (1, 2) is slightly larger than the height of the teeth (4) having the smallest height, wherein a peripheral groove (5) is arranged opposite each crushing tooth (4) with a larger height than the smallest height, in each case on the casing surface (3) of the other roller (1, 2), and the distance between the bottom of this groove (5) and the free end of each tooth (4) with a larger tooth height than the smallest tooth height is equal or similar to the distance between the casing surface (3) of one roller (1, 2) and the tooth (4) of the other roller (1, 2) that has the smallest height.

Description

Twin roller crusher

The invention relates to a twin roller crusher having rollers which are rotatably mounted in a crusher housing, are motor-driven in opposite directions and the centre longitudinal axes of which are directed parallel to one another, wherein the casing of the rollers has arranged thereon crushing teeth which project beyond the casing surfaces, wherein a small gap is formed in each case between the free end of each tooth of one roller and the casing, opposite thereto, of the other roller, wherein the crushing teeth are arranged in rows in the circumferential direction of the rollers and each row of crushing teeth of the first roller is axially adjacent, to a row of crushing teeth of the second roller.

Such twin roller crushers are known in the prior ad and are used in particular in the field of comminution technology in the mining industry, in known twin roller crushers a comminution of rough material, such as for example rock or the like, takes place with the aid of two motor-driven rollers. In this case the centre longitudinal axes of the rollers are usually oriented parallel to one another and horizontally. The direction of rotation of the two rollers is in opposite directions in such a way that the material for comminution usually delivered above the roller gap is drawn into the roller gap by rotation of the rollers and Is comminuted by the crushing teeth of the rollers. Below the roller gap the crushed material can now be transported away for example by a conveyor belt arranged there.

In the solutions known in the prior art the crushing teeth are arranged in rows on the rollers in the circumferential direction of the rollers, wherein contact between the crushing teeth of the first roller and the crushing teeth of the second roller is ruled out. A principal objective of all of these twin roller crushers is to comminute the rough feed material as effectively as possible and to transform it into smaller, uniformly distributed grain fractions. In this case the output material should be capable of being produced as economically as possible whilst at the same time being of high qualify, i.e. having an optimal grain size distribution curve which is suitable for the particular field of application. In this case the comminuting ratio of material fed in to material discharged is a significant parameter for the economic efficiency of such a twin roller crusher. The higher the comminuting ratio of a twin roller crusher is, the fewer machines have to be used, for example in series. Moreover, the comminuting ratio is aiso an indication of the capacity of such a machine with regard to the changing requirements. This means that the quantity of feed material can vary, for example, and the comminution can take place during the crushing process without secondary crushing of the material for comminution to the target grain size.

In known twin roller crushers the most varied tooth geometries are used for comminution.

In a twin roller crusher which is known in the prior art a combination of crushing teeth of smaller and larger structural height are arranged on each roller, in this case the crushing teeth with the larger height comminute larger feed material, whilst the teeth with only a smaller height are responsible for the comminution of smaller feed material.

In such twin roller crushers it is necessary to arrange a plurality of roller pairs one behind the other or to arrange a plurality of twin roller crushers one behind the other in order to obtain the required target grain size. In currently known twin roller crushers the comminuting ratio is for instance 1:3 to 1:4. Furthermore. In known solutions with crushing teeth having different structural heights it is inevitably necessary to synchronise the roller rotation in order to prevent a collision of the teeth. Thus a different rate of rotation of the first roller relative to the second roller is impossible, since this would inevitably lead to a collision of the teeth of the first roller with parts, in particular teeth, of the second roller, WO 2014/161528 discloses a twin roller crusher, in which the teeth of one roller penetrate into depressions In the other roller, so that a particularly high comminuting ratio of for instance 1:20 can be achieved.

Such a twin roller crusher has proved worthwhile in principle, but in this case it is absolutely necessary to carry out the synchronisation of the rotational movement of both rollers in order to avoid a collision between tooth and depression or tooth and casing surface of the other roller.

Based on the aforementioned prior art the object of the present Invention is to improve a twin roller crusher of the aforementioned type with regard to its comminuting ratio, that Is to say to provide a comminuting ratio of >1:4, which crusher dispenses with synchronisation of the rotational movement of the rollers and can thereby be produced cost-effectively and simply and has a long service life.

In order to achieve this object, according to the invention crushing tooth rows of different tooth height are arranged on the casing of the roller, wherein the distance between the casing surfaces of the rollers is slightly larger than the height of the teeth having the smallest height, wherein a peripheral groove is arranged opposite each crushing tooth with a larger height than the smallest height. In each case on the casing surface of the other roller, and the distance between the bottom of this groove and the free end of each tooth with a larger tooth height than the smallest tooth height is equal or similar to the distance between the casing surface of one roller and the tooth of the other roller that has the smallest height.

In such a solution in particular the crushing teeth with a larger height than the smallest height make it possible even for material for comminution having a large grain diameter to be drawn into the comminution region and to be comminuted. Thus the teeth having a larger height are suitable for gripping larger grain sizes of the material to be comminuted and then to comminute it, In the interengaging region of the teeth or of the raised teeth and an opposing slot, to the required target grain size. Without these teeth with a larger height than the smallest height, such material having a larger diameter could not be drawn in and thus also cannot be comminuted. In particular because the distance of both the teeth having a larger height and also the teeth having only a smaller height respectively from the groove base or from the casing surface of the opposing roller are designed to be the same size, an optimal grain size distribution curve which is correspondingly suitable for the respective field of application is achieved.

This takes place independently of the grain size of the delivered material for comminution. Comminuting ratios of far iarger than 1:4 can be achieved with such a twin roller crusher, in this case the rollers without synchronisation can be motor-driven In opposite directions so that a synchronising gear, which necessitates high costs, on the one hand, and increased maintenance effort, on the other hand, can be dispensed with. Furthermore, In this case it is possible, if required or if necessary, for example for cleaning purposes, to drive the rollers at a different rate of rotation in opposite directions relative to one another. In this way in particular an increased cleaning effect is provided.

Moreover, as a result it is possible to move the rollers as near as possible to one another, specifically to a distance which is slightly larger than the height of the smallest tooth. All other teeth, that is to say those having a larger height than the smallest height, engage in a groove arranged on the respective other roller in this region and thus do not impede the movement of the rollers towards one another.

In an alternative means tor achieving the object referred to In the introduction, the invention proposes that rows of crushing teeth with a different tooth height are arranged on the casing surface of each roller, wherein each row of teeth of a roller engages in an opposing groove formed on the other roller, wherein the distances between the free end of each tooth and the base of this groove are the same or a similar size.

In such an embodiment according to the invention, opposite each row of teeth of a first roller there is formed on the other roller a peripheral groove in which the row of teeth of the respective other roller engages. In this way It is possible to move the rollers extremely near fo one another, since a collision of the tooth or teeth of one roller with the roller casing of the other roller is prevented by the grooves which are arranged there and into which the teeth penetrate.

With this solution according to the invention a particularly high comminuting ratio, in particular a substantially higher comminuting ratio than 1:4 of delivered material for comminution is also possible. In this solution, the teeth having a large height draw in material with a larger grain size and comminute it to the target grain size. Also in this solution it is possible to dispense with the use of a gear for synchronisation of the roller rotations which entail high costs and which require intensive maintenance. Moreover, in this case it Is also possible to make the rollers rotate at different speeds, wherein in particular an Independent cleaning of the rollers can take place.

In two embodiments according to the invention it can be particularly preferably provided that all tooth rows or only a tooth row having a larger height than the smallest height, opposite which a corresponding groove is arranged, have a raised tooth back which extends in the circumferential direction, connects the successive teeth of a tooth row to one another and has a depression In each case Immediately before the raised tooth in the direction of rotation of the roller. A tooth back configured In such a way which, following the crushing tooth, engages in the peripheral groove effectively prevents a formation of a so-called oversize grain, that Is to say a grain having a grain size larger than the target grain size in the region of two successive teeth which are spaced apart from one another. Thus the raised back closes the peripheral groove to a dimension at which the grain located therein is crushed fo the target size and possibly smaller. In this case a depression is formed In each case in the direction of rotation of the roller immediately before the raised tooth, and ensures or improves the intake behaviour in particular of the teeth having a larger height than the smallest height. As a result, grains for comminution which have a larger diameter have the possibility of penetrating into the depression before the tooth, in order then to be drawn in by the tooth Into the gap between tooth and groove and to be comminuted there to the target grain size.

Such raised tooth backs connecting the teeth to one another can be formed in particular in teeth 'with a larger height than the smallest height. Moreover, teeth having only the smallest height with such tooth backs with depressions can be connected to one another in order also to improve the intake behaviour of the teeth in this region and to comminute the material located in this region to the target grain size due to the raised back.

Moreover, due to the raised tooth back the feed material to be comminuted is interrupted in its axial alignment and thus the formation of a rod-shaped or scaly material is avoided. Thus the raised tooth back constitutes a limit of the crushing space in the axial direction.

Furthermore, it can be provided particularly preferably that the flanks of the peripheral groove diverge towards the free outer face, wherein the tooth shape of the teeth is adapted to the shape of this groove in such a way that the distance between the flank of the groove and the tooth side wail Is the same as or similar to the distance between the free end of each tooth and groove base.

Such a tooth shape, which engages in a corresponding opposing groove shape on the respective other roller, has proved in practice to be particularly effective and in this case to have a iong service life.

Alternatively, it can be provided particularly preferably that the casing surfaces of both rollers have a corrugated surface, 'wherein the corrugation peaks have the shape of crushing teeth or have crushing teeth, and the corrugation troughs form the groove, wherein, during the rotation of the rollers in opposite directions, in each case a corrugation peak shaped like a crushing tooth or a crushing tooth formed on a corrugation peak of one roller penetrates Into a corrugation trough of the other roller, wherein the spacing gap between the corrugation peak, or the crushing tooth formed on a corrugation peak, and the corrugation trough is in each case the same or similar.

In this case the casing surfaces of both rollers are corrugated, wherein in each case either crushing teeth are arranged on the corrugation peaks or the corrugation peaks are formed as crushing teeth. In this case during the rotational movement of the rollers in opposite directions the crushing teeth in each case engage in a corrugation trough on the other roller. As a result an extremely small roller gap can be achieved, and the comminuting ratio of a roller arrangement designed in such a way is substantially larger than 1:4.

Lastly, it can be provided in particular that the casing surface is formed with crushing teeth and grooves or corrugation peaks in the shape of crushing teeth and corrugation troughs forming a groove of each roller is in each case formed from a plurality of segments which can be individually released and fastened to or on the roller.

Such an arrangement of a plurality of segments which form the casing surface of a crushing roller is known perse and has proved worthwhile.

In this way it is possible to replace individual segment-like regions of the casing of the roller as necessary. This can be the case for example if only individual or a small number of crushing teeth exhibit wear. As a result a particularly cost-effective possibility Is provided by which a machine exhibiting wear can be put into a fully functional state.

Embodiments of the invention are illustrated in the drawings and are described in greater detail below. in the drawings:

Figure 1 show's a first embodiment of a crusher roller according to the invention:

Figure 2 shows a perspective view of a pair of crusher rollers in the working position;

Figure 3 shows a segment of a crusher roller casing;

Figure 4 shows a further embodiment of a pair of crusher rollers In the working position in plan view;

Figure 5 shows the section AA according to Figure 4;

Figure 6 shows the section BB according to Figure 4;

Figure 7 shows the section CC according to Figure 4.

The drawings show crusher rollers 1,2 or pairs of crusher rollers 1,2 of a twin roller crusher. These pairs of crusher rollers 1,2 are usually rotatably mounted In a crusher housing of a twin roller crusher and in this case are motor-driven in opposite directions.

The centre longitudinal axes of the rollers 1, 2 are directed parallel to one another and crushing teeth 4 are arranged on the casing 3 of the rollers 1,2. The crushing teeth 4 in each case project over the casing surface 3. A small spacing gap is formed in each case between the free end of each tooth 4 of one roller 1.2 and the casing 3, opposite thereto, of the other roller 1,2. The crushing teeth 4 are arranged in rows in the circumferential direction of the rollers 1,2, projecting over the casing 3 or the casing surface 3 of the rollers 1,2. In this case each row of crushing teeth 4 of the first roller 1 is axially adjacent to a row of crushing teeth 4 of the second roller 2.

According to the Invention crushing tooth rows 4 of different tooth height are arranged on the casing 3 of the rollers 1,2. In this case the distance between the casing surfaces 3 of the rollers 1,2 is slightly larger than the height of the teeth 4 having the smallest height, A peripheral groove 5 is arranged opposite each crushing tooth 4 with a larger height than the smallest height, In each case on the casing surface 3 of the other roller 1,2. In this case the distance between the bottom of this groove 5 and the free end of each tooth 4 'with a larger tooth height than the smallest tooth height is equal or similar to the distance between the casing surface 3 of one roller 1, 2 and the tooth 4 of the other roller 1,2 that has the smallest height.

In this way an optimal grain size distribution curve which is suitable for the particular field of application is achieved.

Moreover, because the tooth height is also responsible in particular also for the drawing-in, wherein the distances between the tooth back 6 and the roller casing delimit the crushing space, the production of oversize grain is avoided.

Also in the region of the teeth 4 having a larger height the distances from the parts of the opposing roller 1, 2, In this case the groove base, are the same as or similar to the distance between a tooth 4, having only a small height, of one roller 1, 2 and the casing 3 of the other roller 1,2.

With such a twin roller crusher according to the invention a particularly high comminuting ratio of delivered material, specifically far higher than 1:4 can be achieved. Thus it is possible for material delivered with a relatively large grain size to be comminuted to a relatively small target grain size crushed in only one comminution operation. In this case the rotation of the rollers 1,2 driven in opposite directions takes place without the control of a gear as synchronisation, since no synchronisation is necessary in such a solution. As a result are both maintenance effort and resulting downtimes and also costs are avoided.

Moreover, in this case it is possible to drive the rollers 1,2 at different rates of rotation in order to carry out or at least to assist independent cleaning, for example, of the grooves 5 or the regions between the teeth 4 having only a small height.

In the exemplary embodiment of the invention shown n Figures 4 to 7, crushing tooth rows 4 of different tooth height are arranged on the casing 3 of each roller 1, 2. In this case each row of teeth 4 of a roller 1.2 engages in an opposing peripheral groove 5 on the other roller 1,2. Also in this solution the distances between the free end of each tooth 4 of a row of teeth 4 and the groove base of this groove 5 are the same or similar, so that an optimal grain size distribution curve is achieved which is correspondingly suitable for the respective field of application.

This solution also dispenses with the arrangement of a gear for synchronisation and if is possible to make the rollers 1,2 rotate at different speeds, so that the independent cleaning is assisted or takes place, in particular in the region of the grooves 5.

Both described solutions have a particularly long service life with relatively low' production costs. Moreover, with these solutions a comminuting ratio which is significantly enlarged relative to known solutions, namely significantly greater than 1:4, is possible, so that an arrangement of a plurality of twin roller crushers arranged one behind the other is unnecessary, since material having a relatively large grain size can already be comminuted to a material having only a small grain size in one comminution operation.

In the exemplary embodiment illustrated in Figures 1 to 3, between two teeth 4 of a row of teeth 4 which have a iarger height than the smallest height a raised tooth back 6 is formed in each case which connects the successive teeth 4 to one another. In this case a depression 7 is formed immediately before the raised tooth 4 in the direction of rotation of the roller 1,2. In the exemplary embodiment of the invention shown in Figures 4 to 7, this back 6 connecting the teeth 4 is formed between all teeth 4 of a row of teeth 4. In this erase also a depression 7 is formed in each case before the tooth 4 in the direction of rotation. Due to this raised back 6, material for comminution which has a larger grain size than the target grain size and is located inside the groove 5 is comminuted and subsequently discharged. Thus the raised tooth back 6 engages in the region of the groove 5 and closes this or comminutes material located there with a grain size larger than the target grain size to the target grain size.

The depression, which is In each case arranged immediately before the tooth 4 In the direction of rotation of the rollers 1,2. enables an improved intake behaviour of delivered materia] having a particularly large diameter, so that even this can be comminuted to the target grain size in only one comminution operation.

In the exemplary embodiments of the invention shown in the drawings the flanks of the peripheral slot 5 diverge towards the free outer face. In this case the tooth shape of the teeth 4 (Figures 1 to 3) having a larger height or of ail teeth 4 (Figures 4 to 7) is adapted to the shape of this groove 5 in such a way that the distance between the flank of the groove 5 and the respective tooth side wall is the same as or similar to the distance between the free end of each tooth 4 and groove base. As a result a particularly uniform target grain size can be achieved at the same time as a high performance. Moreover, this shape has proved to experience particularly low wear and thus has a long service life.

In an alternative exemplary embodiment, not shewn in the drawings, the casing surfaces 3 of both rollers 1, 2 can also have a corrugated surface. In this case the corrugation peaks have the shape of crushing teeth or crushing teeth 4 are arranged in the region of the corrugation peaks. The corrugation troughs are in each case formed by the grooves 5. In this case, during the rotation of the rollers 1,2 in opposite directions, in each case a corrugation peak shaped like a crushing tooth or a crushing tooth 4 of a corrugation peak of one roller 1, 2 engages in a corrugation trough of the other roller 1,2. Also in this case the spacing gap between the corrugation peak, or the crushing tooth 4 formed on a corrugation peak, and the corrugation trough is in each case the same or similar, so that a particularly uniform target grain size is achieved during comminution.

As can be seen in particular from Figure 3, in a manner which is known per se the casing surface 3 of each roller 1, 2 with crushing teeth 4 and grooves 5 or corrugation peaks in the shape of crushing teeth and corrugation troughs forming a groove 5 of each roller 1, 2 can be formed in each case from a plurality of segment 8s. In this case the segments 8 are arranged so as to be Individually releasable and fixed either to or on the roller 1,2., in this case forming the casing surface 3 thereof. As a result It is possible for rollers 1, 2 which have only a Iltfle damage or a little wear to be restored cost-effectiveiy by replacement of individual segments 8. Thus it is not necessary to renovate an entire roller 1,2 or the casing 3 thereof, but in the event of wear it is only necessary to replace one or more segments 8.

The Invention is not limited to the exemplary embodiment, but can be varied in many ways within the scope of the disclosure.

All individual features and combinations of features disclosed in the description and/or drawings are regarded as essential to the invention.

List of references 1 roller 2 roller 3 casing surfaces of 1.2 4 crushing tooth 5 groove 6 tooth back 7 depression in 6 8 segment

Claims

1. Twin roller crusher having rollers (1, 2) which are rotatably mounted in a crusher housing, are motor-driven In opposite directions and the centre longitudinal axes of which are directed parailel to one another, 'wherein the casing of the rollers (1, 2) has arranged thereon crushing teeth (4) which project beyond the casing surfaces (3), wherein a small gap is formed in each case between the free end of each tooth (4) of one roller (1,2) and the casing (3), opposite thereto, of the other roller (1.2), wherein the crushing teeth (4) are arranged In rows in the circumferential direction of the rollers (1, 2) and each row of crushing teeth (4) of the first roller (1) is axially adjacent to a row of crushing teeth of the second roller (2), characterised in that, crushing tooth rows of different tooth height are arranged on the casing (3) of the rollers (1,2), wherein the distance between the casing surfaces (3) of the rollers (1, 2} is slightly larger than the height of the teeth (4) having the smallest height, wherein a peripheral groove (5) is arranged opposite each crushing tooth (4) with a larger height than the smallest height, in each case on the casing surface (3) of the other roller (1, 2), and the distance between the bottom of this groove (5) and the free end of each tooth (4) with a larger tooth height than the smallest tooth height is equal or similar to the distance between the casing surface (3) of one roller (1,2) and the tooth (4) of the other roller (1,2) that has the smallest height.

2. Twin roller crusher according to the preamble to claim 1, characterised in that rows of crushing teeth (4) with a different tooth height are arranged on the casing surface (3) of each roller (1, 2), wherein each row of teeth (4) of a roller (1,2) engages in an opposing groove (5) formed on the other roller (1,2), wherein the distances between the free end of each tooth (4) and the base of this groove (5) are the same or a similar size.

3. Twin roller crusher according to claim 1 or 2, characterised in that ail tooth rows (4) or only a tooth row having a larger height than the smallest height, opposite which a corresponding groove (5) Is arranged, have a raised tooth back (6) which extends in the circumferential direction, connects the successive teeth (4) of a tooth row to one another and has a depression (7) in each case immediately before the raised tooth (4) in the direction of rotation of the roller (1, 2).

4. Twin roller crusher according to one of claims 1 to 3, characterised in that the flanks of the peripheral groove (5) diverge towards the free outer face, wherein the tooth shape of the teeth (4) is adapted to the shape of this groove (5) in such a way that the distance between the flank of the groove (5) and the tooth side wall is the same as or similar to the distance between the free end of each tooth (4) and groove base.

5. Twin roller crusher according to one of claims 1 to 3, characterised in that the casing surfaces (3) of both rollers (1, 2) have a corrugated surface, wherein the corrugation peaks have the shape of crushing teeth or have crushing teeth (4), and the corrugation troughs form the grooves (5), wherein, during the rotation of the rollers (1,2) in opposite directions, in each case a corrugation peak shaped like a crushing tooth or a crushing tooth (4) formed on a corrugation peak of one roller (1, 2) penetrates into a corrugation trough of the other roller (1, 2), wherein the spacing gap between the corrugation peak, or the crushing tooth (4) formed on a corrugation peak, and the corrugation trough Is in each case the same or similar.

6, Twin roller crusher according to one of claims 1 to 5, characterised in that the casing surface (3) is formed with crushing teeth (4) and grooves (5) or corrugation peaks In the shape of crushing teeth and corrugation troughs forming a groove (5) of each roller (f, 2) Is in each case formed from a plurality of segments (8) which can be individually released and fastened to or on the roller (1,2).