WO2019012039A1 - SEGMENT SEGMENT WITH WEAR PROTECTION ELEMENTS - Google Patents

Abstract

The present invention relates to a sieve segment (10) of a sieve device for separating or classifying feed material, in particular mineral crushed materials such as oil sands, in at least two grain fractions, wherein the sieve segment (10) has a substantially sieve-shaped base plate (12) and a plurality of sieve passages (14 ), wherein on the base plate (12) at least one wear protection element (16) is arranged, wherein the at least one wear protection element (16) at least partially abuts the surface of the base plate (12) and forms the inner surface of a Siebdurchlasses (14) and wherein the Wear protection element (16) is formed of a hard metal having a cobalt content (Co) of 5 - 30%, preferably 10 - 20%, in particular 15%.

Description

 Sieve segment with wear protection elements

The invention relates to a sieve segment, as well as a screening device with wear protection elements.

For the preparation of raw materials, in particular of mineral crushed materials, such as oil sands, coal and ores, such as iron ore and nickel ore screening devices are used with a variety of sieve segments that classify by vibration the material to be crushed or already comminuted in at least two grain fractions. Such a sieve device is described for example in DE102007034512B3.

The materials to be classified are often high-hardness materials that are highly abrasive. This occurs on the surface of the sieve segments heavy wear, which requires very short maintenance intervals and high processing costs of the sieve segments.

From WO 2017009288 Al a sieve with a plurality of plate-shaped wear protection elements is already known, which form the surface of the sieve. These wear protection elements are extremely resistant to wear, but at the same time also react relatively brittle in the event of impacting loads. It has been found that such plate-shaped wear protection elements can flake off the surface of the screen when used for classifying highly abrasive but also very hard material. This often leads to very high wear and damage to the entire screen, which can also result in a failure of the entire screen.

On this basis, it is an object of the present invention to provide a screen segment of a screening device, which has a high wear resistance in an application for the classification of highly abrasive materials and at the same time in the operation of Siebeirichtung by the impact load of the material to be classified is not solvable.

This object is achieved by a device having the features of the independent device claim 1. Advantageous developments emerge from the dependent claims. A sieve segment of a sieve device for separating or classifying feedstock, in particular mineral crushed materials such as oil sands, in at least two grain fractions comprises according to a first aspect a substantially sieve-shaped base plate and a plurality of sieve passages. At least one wear protection element is arranged on the base plate of the sieve segment, wherein the wear protection element bears at least partially on the surface of the base plate and forms the inner surface of a sieve passage. The wear protection element is formed from a hard metal having a cobalt content of 5 to 30%, preferably 10 to 20%, in particular 15%. A sieve segment forms at least part of a sieve device, in particular the sieve surface of a sieve device. Preferably, a plurality of sieve segments are arranged side by side to form a sieve surface. It is also conceivable that a screening device has only one sieve segment which forms the sieve surface. The material to be classified is, for example, mineral crushed materials, such as oil sands, coal and ores, such as iron ore and nickel ore or cement clinker.

The base plate preferably forms the lower region of the sieve segment facing away from the material to be classified and is in particular designed in the form of a plate with a plurality of passages. The passages of the base plate are aligned with the screen passages of the screen segment and serve to classify the material, with material having a size below a certain grain size falling through the screen passages and the material falls above the particular grain size laterally from the surface of the screening device. The sieve passages are for example round or rectangular and arranged in rows to each other, so that the largest possible number of Siebdurchlässen is arranged side by side. For example, the Siebdurchlässe are evenly spaced from each other and have the same or different sizes.

Preferably, each screen segment has a plurality of wear protection elements, which are arranged side by side and in particular uniformly spaced from each other and form the surface of the sieve segment. In particular, the entire surface of the screening segment, which can come into contact with the material to be classified, covered with wear protection elements. Each wear protection element has at least one sieve passage, wherein the sieve passage extends through the wear protection element. It is also conceivable that a wear protection element has a plurality of sieve passages having. Each sieve passage is preferably completely formed by a wear protection element, wherein the wear protection element in particular forms the complete inner surface of the sieve passage. Each wear protection element is preferably formed in one piece. A wear protection element, which forms the inner surface of the screen passage and rests on the surface of the base plate is connected to pointing in different directions surfaces with the base plate, so that the wear protection element is particularly difficult to remove from the base plate. The cobalt content (Co) of 5 to 30%, preferably 10 to 20%, in particular 15%, of the hard metal ensures a high impact resistance of the cemented carbide. A breakage of the hard metal by an impact occurring during the classification process is avoided with said carbide material. In combination with the geometry of the wear protection element, which partially rests against the surface of the base plate and forms the inner surface of a sieve passage, optimum wear protection is achieved. The risk of detachment or failure of the wear protection element is reliably reduced. The cobalt preferably serves as a binder for a further constituent of the hard metal, such as tungsten carbide. The stated cobalt content has proved to be particularly advantageous in the application as wear protection of sieve segments, since such a binder content provides a particularly suitable impact resistance of the hard metal.

According to a first embodiment, the base plate has a plurality of passages and attached to each passage a wear protection element. Preferably, exactly one wear protection element is attached to each passage. This allows easy attachment of the wear protection elements on each passage in the base plate.

According to another embodiment, at least two wear protection elements are interconnected. For example, the wear protection elements are materially welded together, glued or soldered. A positive connection of at least two wear protection elements is conceivable. Preferably, the wear protection element on the collar, in particular the region which rests on the upper side of the base plate, firmly connected to each other. The wear protection elements are connected to each other, for example, prior to insertion into the passages of the base plate. This allows a simple and quick installation of wear protection elements on the base plate. The wear protection element is formed in particular from a ceramic. The hard metal of the wear protection element preferably comprises sintered tungsten carbide, chromium carbide, titanium carbide, niobium carbide or boron carbide or a combination of these materials. Hard metal and / or ceramic offer a particularly high level of wear protection and therefore significantly increase the service life of the wear protection elements. The hard metal of the wear protection element has, according to another embodiment, a tungsten carbide content of 70-95%, preferably 80-90%, in particular 85%. Such a tungsten carbide content, especially in conjunction with the cobalt content, ensures a particularly high impact resistance, the cobalt serving as a binder. The contents of cobalt and tungsten carbide are by mass (by mass).

The tungsten carbide of the hard metal of the wear protection element has according to a further embodiment, a grain size of 1 - 25μιτι, preferably 10 - 20 μιτι, in particular 5 μιτι on. It has been found that the grain size of tungsten carbide is an important factor in achieving the desired hardness of the cemented carbide. The mentioned grain size represents an optimum for the application of the hard metal as Siebverschleißschutz grain size, which requires neither an unstable nor too soft material.

The hard metal of the wear protection element has according to another embodiment, a hardness of 800 -1300HV20, preferably 900 - 1200HV20, in particular 1050HV20. Such a degree of hardness results in wear resistance and impact resistance, which is ideally suited for applications as screen wear protection. It has been found that such a degree of hardness, in particular for wear protection elements which at least partially form the inner surface of a sieve passage, is advantageous since the impact stress on the sieve passages can be increased.

According to a further embodiment, each wear protection element forms in each case exactly one sieve passage. As a result, the manufacturability of the wear protection elements is simplified. The Siebdurchlässe are arranged in alignment with the passages in the base plate, so that, for example, a wear protection element with a plurality of Siebdurchlässen may have a lower tolerance in order to be introduced into the passages of the base plate can.

The base plate according to a further embodiment of steel, in particular a high temperature resistant and ductile steel is formed. Steel as a material for the base plate allows a simple and inexpensive production of the base plate. Since the base plate is exposed to little or no wear, the formation of a relatively ductile steel is possible. The wear protection element is connected in accordance with a further embodiment cohesively / positively and / or positively connected to the base plate. For example, the base plate has a complementary to the wear protection element surface, such as a tongue and groove connection. The wear element is clamped, for example, with the base plate, wherein the outer shape of the wear protection element is in particular slightly larger than the diameter of the passage formed in the base plate and the wear protection element is clamped in the passage. For example, the wear protection element with the base plate additionally or exclusively soldered, welded or glued. According to a further embodiment, the base plate has a plurality of passages and the wear protection element abuts against an inner surface of a passage in the base plate. In particular, the inner surface of the passage in the base plate is connected to an outer surface of the wear protection element by positive engagement, adhesion or material bond. In particular, the wear protection element is completely against the entire inner surface of the passages in the base plate. The wear protection element is in particular inserted or pressed into the passages of the base plate.

The wear protection element is integrally formed according to a further embodiment. According to a further embodiment, the wear protection element is sleeve-shaped. In particular, the wear protection element has a quadrangular or round cross section. The upper edge of the sleeve-shaped wear protection element is formed for example by a collar which protrudes at an angle of about 90 ° to the sleeve-shaped portion and is made for example by folding. The wear protection elements are preferably also made by powder metallurgy and sintered. The collar is preferably on the surface of the base plate. The wear protection elements are in particular arranged side by side on the surface of the base plate, that the collar of two adjacent wear protection elements abut each other. Such a wear protection element is particularly simple and can be produced in large quantities. According to a further embodiment, the base plate has a plurality of passages, wherein the outer geometry of the wear protection element corresponds to the geometry of a passage, in particular is designed to be complementary thereto. It is also conceivable that at least one wear protection element forms a plurality of sieve passages, wherein these have, for example, a different or the same size. The wear protection elements have, for example, a thickness of 3-50 mm, in particular 6-15 mm, preferably 10 mm.

The invention further comprises a sieve device comprising at least one sieve segment, as described above, and at least one vibration exciter communicating with the at least one sieve segment for vibrating it or at least one drive communicating with the at least one sieve segment to rotate it. The sieve segments are arranged, for example, side by side on a support of the screening device. Preferably, the screening device has a plurality of screen segments arranged side by side in rows. The sieve segments are in particular mounted in such a way that the sieve device has a surface inclined to the horizontal, for example at an angle of 5-20 °. This allows for optimal classification of material applied to the surface of the screen. For example, the sieve device is a drum sieve, wherein one or a plurality of sieve segments form the sieve surface of the drum sieve and are driven in rotation.

According to one embodiment, the screening device has a plurality of sieve segments with sieve passages, the size of the sieve passages of the sieve segments being at least partially different over the length of the sieve device. In particular, at one end, preferably at the end at which the material to be classified is applied to the screening device, the screening device has smaller sieve passages than at the opposite end of the screening device. Preferably, the sieve passages increase over the length of the sieve means from the feed end to the opposite end of the sieve means. This allows efficient classification of the feedstock into a plurality of different grain sizes, wherein at the feed end of the screening device, the coarse material and over the length of the screening device material of smaller grain size is screened out. In particular, the screening device has sieve passages of a size of 30 × 30 mm to 150 × 150 mm. Preferably, the thickness of the wear protection elements over the length of the screening device is formed differently. For example, in the areas where the screen has small size screen passages, the wear protection elements have a large thickness of about 8mm to 40mm, with wear protection elements having a small thickness of about 1.5mm to 30mm in an area where the screen has large screen passages respectively.

Description of the drawings

The invention is explained in more detail below with reference to several embodiments with reference to the accompanying figures.

Fig. 1 shows a schematic representation of a section of a sieve segment in a plan view according to an embodiment.

FIG. 2 shows a schematic illustration of a detailed view of the sieve segment in a sectional view according to the exemplary embodiment of FIG. Fig. 3 shows a schematic representation of a wear protection element in a plan view according to an embodiment.

4 shows a schematic illustration of a wear protection element in a sectional view according to the exemplary embodiment of FIG. 3.

Fig. 1 shows a section of a screening segment 10 for classifying coarse-grained material, in particular mineral material from an open pit, mineral crushing materials, such as oil sands, coal and ores, such as iron ore and nickel ore or cement clinker, in at least two particle sizes. The screen segment 10 includes a base plate 12 that includes a plurality of passages that extend through the base plate 12. By way of example, fourteen sieve passages 14 in four rows are shown side by side in the section of the sieve segment. The sieve passages 14 are preferably uniformly spaced from each other and arranged in rows next to each other. By way of example, the sieve passages 14 are formed square, as well as deviating forms such as circular, rectangular or polygonal are conceivable. The base plate 12 is arranged on the lower, the material to be classified side facing away from the screening segment 10 and, for example, made of steel, in particular a high temperature resistant and ductile steel. By way of example, the base plate 12 has a rectangular cross-section.

On the surface, in particular in the direction of the material to be classified facing surface of the base plate 12, a plurality of wear protection elements 16 is attached. In the exemplary embodiment of FIGS. 1 to 4, the number of wear protection elements 16 on a sieve segment 10 corresponds to the number of sieve passages 14, so that exactly one wear protection element 16 is attached to each sieve passage 14. It is also conceivable to provide a plurality of screen passages 14 with a wear protection element 16, wherein a wear protection element 16 is attached to a plurality of Siebdurchlässen 14.

For example, a plurality of such sieve segments 10 are arranged side by side in a plane on a support and forms a screening device.

The Siebdurchlässe 14 are rectangular, in particular square, formed and arranged adjacent to each other in rows. The section of the screening segment 10 shown in FIG. 1 has, by way of example, 16 sieve passages 14, wherein in each case four sieve passages 14 are arranged next to one another in a row. The base plate 12 is formed for example of steel.

FIG. 2 shows a detailed view of the cross section through the sieve segment 10 marked in FIG. 1. The base plate 12 of the sieve segment 10 has an upper surface pointing in the direction of the material to be classified and an opposite lower surface. Furthermore, the base plate 12 at each screen passage 14 each have four inwardly facing inner surfaces. The wear protection member 16 is attached to the inner surface of the base plate 12 on the screen passage 14 and on the upper surface of the base plate 12. In particular, the wear protection element 16 with the base plate 12 is firmly bonded and / or positively connected, preferably welded, soldered or glued.

The wear protection element 16 is shown in a plan view and a sectional view in Figs. 3 and 4 and has a sleeve-shaped geometry with a quadrangular cross-section. The wear protection element 16 is formed with four side surfaces 18, which are arranged substantially perpendicular to each other. The side surfaces 18 of the wear protection element 16 form the screen passage 14, which extends through the wear protection element 16. The Side surfaces 18 of the wear protection element 16 also have a collar 20 which protrudes at right angles from the screen passage 14.

The sleeve-shaped wear protection element 16 has an outer geometry which corresponds to the geometry of a passage in the base plate 12, so that the outer surface of the wear protection elements 16 abuts each of the inner surfaces of a Siebdurchlasses 14 and is connected thereto by positive engagement. In particular, the outer diameter of the wear protection element 16 is slightly larger than the diameter of the passages in the base plate 12, so that the wear protection element 16 is clamped to the base plate. For example, the inner surfaces of the passages in the base plate 12 are completely covered by the wear protection element 16, so that they do not come into contact with the material to be classified.

The collar 20 of the wear protection elements 16 rests on the upper surface of the base bar 12. The collar 20 of the wear protection elements 16 are preferably made of a completely sleeve-shaped wear protection element 16 by folding or powder metallurgy, so that they form an angle of about 90 ° to the sleeve-shaped portion of the wear protection element 16. In the plan view of Fig. 3, the collar 20 is shown, wherein this has a conditional by the edging octagonal shape. Wear protection elements 16 are, as shown in Fig. 1, arranged side by side, so that the surface of the base plate 12 is completely, except for a plurality of square recesses, covered by wear protection elements 16. The collar 20 of two adjacent wear protection elements 16 abut each other. The wear protection element is formed at least partially or completely from a hard metal, such as sintered tungsten carbide, titanium carbide, boron carbine, chromium carbide, niobium carbide or a ceramic or a combination of these materials. LIST OF REFERENCE NUMBERS

 10 sieve segment

 12 base plate

 14 passage

16 wear protection element

18 side surface

 20 collars

 22 sieve passage

Claims

claims l. Sieve segment (10) of a sieve device for separating or classifying feed material, in particular mineral crushed materials such as oil sands, in at least two grain fractions, wherein the sieve segment (10) comprises a substantially sieve-shaped base plate (12) and a plurality of sieve passages (14),  characterized in that  on the base plate (12) at least one wear protection element (16) is arranged, wherein the wear protection element (16) at least partially on the surface of Base plate (12) rests and forms the inner surface of a Siebdurchlasses (14), wherein the wear protection element (16) is formed of a hard metal having a cobalt content (Co) of 5 - 30%, preferably 10 - 20%, in particular 15%. The screen segment (10) of claim 1, wherein the baseplate (12) has a plurality of apertures and a wear protection member (16) is attached to each aperture. Sieve segment (10) according to one of the preceding claims, wherein at least two wear protection elements (16) are interconnected. 4. sieve segment (10) according to any one of the preceding claims, wherein the hard metal of the wear protection element (16) has a tungsten carbide content of 70 - 95%, preferably 80 - 90%, in particular 85%. 5. sieve segment (10) according to claim 4, wherein the tungsten carbide of the hard metal of the wear protection element (16) has a particle size of 1 - 25pm, preferably 10 - 20 μιτι, in particular 5 μιτι. 6. sieve segment (10) according to any one of the preceding claims, wherein the hard metal of the wear protection element (16) has a hardness of 800 -1300HV20, preferably 900 - 1200HV20, in particular 1050HV20. 7. sieve segment (10) according to any one of the preceding claims, wherein each wear protection element (16) in each case exactly one sieve passage (14) is formed. 8. sieve segment (10) according to any one of the preceding claims, wherein the base plate (12) made of steel, in particular a high temperature resistant steel is formed. 9. sieve segment (10) according to any one of the preceding claims, wherein the wear protection element (16) is cohesively, non-positively and / or positively connected to the base plate (12). A screen segment (10) according to any one of the preceding claims, wherein the base plate (12) has a plurality of passages and the wear protection element (16) on an inner surface of a passage in the base plate (12) is present. 11. sieve segment (10) according to any one of the preceding claims, wherein the wear protection element (16) is integrally formed. 12. sieve segment (10) according to one of the preceding claims, wherein the wear protection element is sleeve-shaped. 13. Screen segment (10) according to one of the preceding claims, wherein the base plate (12) has a plurality of passages and the outer geometry of the Wear protection element (16) corresponds to the geometry of a passage. 14. Sieve segment (10) according to any one of claims 1 to 6 and 8 to 13, wherein each wear protection element forms a plurality of Siebdurchlässen (14). 15. Sieving device comprising at least one sieve segment (10) according to one of the preceding claims, at least one vibration exciter communicating with the at least one sieve segment (10) in order to swing it or at least one drive connected to the at least one sieve segment ( 10) to rotate it. 16. Screening device according to claim 15, wherein the screening device has a plurality of sieve segments (10) with sieve passages (14), the size of the sieve passages (14) of the sieve segments (10) being at least partially different over the length of the sieve device.