WO1998011991A1

WO1998011991A1 - Partition for mills

Info

Publication number: WO1998011991A1
Application number: PCT/EP1997/005154
Authority: WO
Inventors: Erich Pichlmaier; Peter Kindel; Helmut KRÜNES
Original assignee: Christian Pfeiffer Maschinenfabrik Gmbh
Priority date: 1996-09-20
Filing date: 1997-09-19
Publication date: 1998-03-26
Also published as: AU4460097A

Abstract

A partition for mills, in particular a transfer or discharge wall for tube mills, ball mills and the like, has partition panels (3) that can be fixed on a wall frame. In order to improve load conditions in duty, minimise standstill times and maintenance operations, and reduce the risk of accidents when the partition panels are replaced, the partition panels are produced with areas, layers or plates of a hard, brittle and wear-resistant material (8) and of a tough, elastic and less wear-resistant but break-proof material (5).

Description

Mill partition

The invention relates to a mill partition, in particular a tubular mill partition as a transfer or discharge wall, according to the preamble of claim 1.

Mill partitions are used in tube mills, ball mills and the like for the grinding of mineral raw materials in the dry and wet grinding process, in particular in the grinding of cement, clinker, limestone and gypsum. The grinding media of the individual grinding chambers are separated by dividing the tube mills into grinding chambers. The mill partitions are designed from the point of view that regrind above a defined grain size and grinding media remain in a grinding chamber of the mill.

As a rule, mill partitions consist of a diaphragm wall at the front in the direction of the material flow, of slit plates, a wall structure and a rear wall of rear wall plates with a central air passage opening which is provided with a grille. Through the slotted plates, which are usually designed in the form of circular segments, the ground material enters the wall structure below a defined grain size, which is predetermined by the dimensions of the slits of the slotted plates. The wall scaffold gives a mill partition the required stability and has essentially radially arranged partition plates, which are also referred to as lifting blades. The dividing plates divide the wall structure, or an intermediate area delimited by the diaphragm wall and the rear wall, into chambers similar to a circular sector. The ground material is lifted from the separating plates or lifting blades and slides on them after exceeding a material-specific angle of repose in the direction of the wall center or air passage opening and reaches the subsequent grinding chamber via appropriately designed material outlet openings. Compared to this subsequent grinding chamber, the wall structure is closed off by the rear wall panels, which are generally designed without material outlet slots. These rear wall panels are not required for mill discharge walls.

The dividing wall plates of a mill dividing wall, which comprise both the segment plates of a diaphragm wall and that of a rear wall, are subjected to considerable pressure and impact stress due to the grinding media fillings. In addition to the grinding media, the material to be ground also leads to fretting and erosion wear, so that the partition wall plates must be replaced as a result. Associated with this is an operational shutdown of the mill and thus an increase in operating costs. Because of the considerable weight of a partition plate, assembly is not only complex, but also involves an accident risk. This also applies to worn, worn partition panels, which are extremely heavy and unwieldy, for example with a residual weight of around 40 to 50%, which is common in the cement industry. It is known to manufacture partition plates for tube mills from a wear-resistant material. So hardened rebated steel plates and cast steel plates were used. However, these hard and brittle, more wear-resistant materials have only an inadequate break resistance. The wear-resistant but fragile partition panels can therefore also require relatively early removal and costly interruption of mill operations.

The invention is based on the object of providing a mill partition wall which, with an extraordinarily long service life, enables largely maintenance-free operation and a particularly simple exchange of partition wall plates with an extremely low risk of accident and a minimized health hazard.

According to the invention the object is achieved by the features of claim 1. Useful and advantageous configurations are contained in the subclaims and in the description of the figures.

A basic idea of the invention is to produce partition plates for tube mills from different materials and to make the selection of the materials and their geometric design such that the partition plates have both high wear resistance and high break resistance.

According to the invention, the partition panels consist of a combination of at least two materials, one material being hard and brittle and therefore particularly wear-resistant or wear-resistant, and a second material tough and elastic and not very wear-resistant, but is unbreakable.

In a preferred embodiment variant, partition walls according to the invention have partition wall panels with a first layer or panel made of a tough elastic material and a second layer or panel made of a highly wear-resistant material. The connection between the two layers or plates can be made by screwing, gluing, clamping or cladding.

The second layer or plate can be in the form of a flat, in particular plate-shaped, geometric body or in the form of a plurality of plate-shaped elements, e.g. B. hard metal platelets, on the first layer or plate.

The first, tough and elastic layer or plate designed as a carrier has, in particular, a greater thickness than the second layer or plate designed as a wear layer.

Hard metals, plastics, ceramic and metal-ceramic materials and hard materials which have the required hardness and wear resistance can be used as materials for the wear layer or plates.

Unhardened, tough and break-proof rolled steel plates can be used for the first layer, which is designed as a support plate. A relatively thin but highly wear-resistant wear layer is applied to this support structure. A composite material, for example a steel carrier plate with a welded-on tungsten carbide wear layer or a perforated plate, can be used as the wear layer highly wear-resistant elements in the form of geometric bodies which are accommodated in the holes can be used.

In principle, the geometric bodies can be placed in openings or recesses, e.g. be arranged in blind holes, the base material of the wear layer or wear plate. In terms of manufacturing technology, however, it is particularly advantageous to use a perforated plate for the wear layer or plate, which is made of a tough and elastic material, for example rolled steel. The complementary geometrical bodies can be inserted and fastened into the holes or holes in the sheet.

The attachment of the wear layer or plate to the lower carrier layer or plate with the aid of an adhesive is particularly advantageous. A partition panel according to the invention produced by such an adhesive connection is particularly simple and efficient to produce.

A perforated plate with regularly formed bores or openings is expediently used as a tough, elastic plate or layer of the wear layer or plate. After the correspondingly designed geometric bodies have been received and fastened in the openings, a partition wall plate is formed which is designed to be highly wear-resistant and break-proof at least in an area directed towards a grinding chamber.

Circular openings are preferably formed in a tough elastic rolled steel plate, which are suitable for receiving cylindrical geometric bodies. The geometric bodies are expediently dimensioned such that they have a predeterminable protrusion after arrangement and fastening in the complementary openings of the wear layer or plate and extend with a base to the support structure, ie to the first layer or plate and with the base of the wear layer or -plate aligned.

An advantage of the sandwich-like partition plates is that the wear layer or wear plates can have a lower thickness than previously known partition plates due to their extraordinarily high wear resistance and break resistance.

The lower overall thickness has an advantageous effect on the weight of the mill partition according to the invention, which not only results in lower production costs due to the lower use of material, but also makes assembly and disassembly more efficient. In particular, the risks associated with the assembly and disassembly of the relatively heavy mill partition plates known to date are considerably reduced or eliminated.

A tough, break-resistant steel can be used for the thin, highly wear-resistant layer or plate formed like a matrix, as for the first layer or plate. Highly wear-resistant materials such as high-alloy steels, sintered metals, ceramics or metal ceramics are suitable for the geometric bodies integrated in the wear plate or plates.

Combinations of these materials can advantageously be used. For example, sales waistband are used. A cylinder jacket made of steel can be connected to a centrally received ceramic cylinder and form a geometric body.

Further alternative designs are block-like bodies which are designed as cubes, rectangles or polygons. The attachment in a perforated sheet steel plate of a wear plate, for example, is expediently carried out by pressing, gluing or soldering.

As a rule, the partition plates of a mill partition designed in the form of a ring segment have an identical design and material combination.

Depending on the degree of wear of a mill partition, it can be advantageous to design the ring segments with different wear-resistant partition plates. For example, the partition wall plates of the inner wall ring delimiting an air passage opening can have a lower wear resistance than the partition wall plates which form the outer wall ring. The partition plates of the inner wall ring can have, for example, smaller and / or a smaller number of geometric bodies in their wear layer or plate. In a further embodiment variant, the geometric bodies made of a wear-resistant, in particular highly wear-resistant material are arranged in a matrix-like carrier layer. The wear layer is thus punctiform and integrated in the supporting structure. The arrangement and number of protrusions of the geometric bodies can be provided as in the sandwich formation. In a further embodiment, the geometric bodies made of a wear-resistant or highly wear-resistant material are arranged in matrix-like carrier layers. The wear layer is thus punctiform and integrated in the base layer. Arrangement, number, dimensioning and overhang can be provided as with the sandwich structure with integrated geometric bodies.

The invention is explained below with reference to a drawing; in this show in a highly schematic representation

Figure 1 is a plan view of a first embodiment of a partition plate according to the invention.

FIG. 2 shows a section along line II-II according to FIG. 1;

3 shows a plan view of a second embodiment variant of a partition plate;

4 shows a section along line IV-IV according to FIG. 3;

Fig. 5 is a plan view of a further embodiment of a partition plate according to the invention and

6 is a section along line VI-VI of FIG .. 5

Fig. 1 shows a partition plate 3, which is designed like an annular segment and is provided for a diaphragm wall. The partition plate 3 has slots 6 through which regrind with a corresponding grain size gets into a wall structure of a mill partition (not shown).

The partition wall plate 3 is provided with fastening areas 4 for fastening to the wall or supporting structure of the mill partition. The wear-resistant design of the partition wall panels 3 on a surface 15 which faces a grinding chamber (not shown) can be seen in FIG. 2. 2 also illustrates the conical design of the slots 6, which have a diameter that increases in the direction of the mill partition or discharge wall.

The partition wall plate 3 is designed like a segment of a circle and has two sandwich-like layers or plates 5, 8, which are connected via an adhesive layer 11, for example an adhesive. The wear layer consists of a hard metal and was connected to the carrier plate 5 before the slots 6 were formed. Fig. 2 illustrates that the wear layer 8 has a lower thickness than the carrier plate 5. Instead of hard metal, other materials, for example plastics, ceramic and metal-ceramic materials can also be used for the wear layer or wear plates 8.

The main advantage of wear-resistant plating is that it is inexpensive to manufacture, lighter in weight due to the lower thickness of the partition panels, and quicker and safer to assemble and disassemble.

Fig. 3 shows an alternatively designed partition wall plate 3. The partition wall plate 3 is in turn circular segment formed, but provided for a rear wall of a partition and therefore has no slots.

The partition plate consists of two sandwich-like layers or plates 5, 8 (see Fig. 4). Analogous to the design according to FIGS. 1 and 2, a first layer or plate 5 is designed as a carrier plate or supporting structure and consists of a tough, elastic and unbreakable material, for example of cast steel. On this first layer or plate 5 a wear layer 8 is arranged like a plate, which represents a geometrically structured material combination of a highly wear-resistant and brittle material and a tough, elastic and unbreakable material.

FIGS. 3 and 4 show a possible arrangement and design of the wear layer or plate 8, which covers the entire first layer or base plate 5. The wear layer 8 is designed as a perforated plate 18. Ceramic cylinder sections are fastened in the through openings or holes 9 of the perforated plate 18 as wear-resistant geometric bodies or elements 7. These are dimensioned such that they are positively but with a small projection 13, which reduces the degree of wear of the perforated plate 18.

The perforated plate 18 and the first layer or plate 5 can basically be made of the same material. However, it is expedient to manufacture the perforated plate from a more wear-resistant material. The connection of the two layers or plates 5, 8 is advantageously carried out with the aid of an adhesive, which enables fast and uncomplicated attachment and, moreover, if necessary, a separation of the layers or plates 5, 8, for example when heated. The geometric bodies 7 of the wear layer or plate 8 can also be glued in. They can also be pressed in, welded or soldered.

The sectional view of FIG. 4 shows that the highly wear-resistant plate or layer 8 has a lower thickness than the first elastic carrier layer 5.

5 and 6, a further embodiment of a partition plate 3 is shown, which corresponds to the fastening areas 4 and the annular segment-like embodiment of the variant of FIG. 3.

A base or support plate 5 has regularly arranged bores 9, which are designed as blind holes (see FIG. 6). These holes 9 are made in the matrix-like carrier plate or layer 5. The carrier layer 5 consists of a tough, elastic material and is designed, for example, as a rolled steel plate.

Circular cylinder sections are used as geometric bodies 7 in the regularly arranged and identically designed bores 9, which consist of a highly wear-resistant material, for example a high-alloy steel, a ceramic or metal-ceramic material.

FIG. 6 shows that the geometric bodies 7 protrude with a slight protrusion 13 over a surface 15 of the partition plate 3 or the carrier layer 5. By appropriate dimensioning of the geometric body of the overhang and the distances between the geometric Bodies which are adapted in particular to the material to be comminuted and the size of the grinding media can be achieved in that the partition wall plates consisting of this material combination have an extraordinarily high wear resistance and at the same time the required break resistance. These properties are exhibited, for example, by a partition wall plate 3 made from a rolled steel plate made of ST 37 as a carrier layer or carrier plate 5 and ceramic blocks with a cross section of approximately 15 × 15 mm and a height of approximately 20 mm, which are glued into the bores 9 and incorporated therein , on. These partition plates 3 ensure an extremely long service life.

The high wear resistance also makes it possible to use partition wall panels with a smaller wall thickness, which on the one hand reduces the material costs and also achieves a lower weight. Assemblies and disassemblies can therefore be carried out more quickly and essentially without risk of injury. Another advantage is that downtimes and maintenance work are minimized due to the high wear resistance and the required break resistance, so that the efficiency of the grinding process can be increased.

Claims

PATENT CLAIMS

1. Mill partition, in particular transfer and discharge wall for tube mills, ball mills and the like, with partition plates (3) which can be fixed to a wall structure, characterized in that the partition plates (3) have at least two material areas, which as layers or plates are formed such that a first layer or plate (5) consists of a tough, elastic material and a second layer is connected as a wear layer or plate (8) to the first layer or plate (5), the wear layer (8) being flat or is formed selectively from a highly wear-resistant material.

2. Mill partition according to claim 1, characterized in that the wear layer or plate (8) is fastened by screw connections, adhesive and / or clamping connections to the first layer designed as a support plate (5).

3. Mill partition according to claim 1 or 2, characterized in that the wear layer or plate (8) has a lower thickness than the first layer or support plate (5).

4. Mill partition according to one of the preceding claims, characterized in that a soft, elastic steel and in particular uncured rolled steel plates are used as the material for the support plate (5).

5. Mill partition according to one of the preceding claims, characterized in that the wear layer or plates (5) hard metals, hard materials, ceramic and metal-ceramic materials and plastics with the required hardness and wear resistance are used for the wear layer or plates.

6. Mill partition according to one of claims 1 to 3, characterized in that with the first layer or support plate (5) at least one second layer or plate (8) is connected, which is designed as a wear layer or plate (8) and from a tough, elastic material (18) with geometrical bodies (7) arranged therein made of a highly wear-resistant material.

7. mill partition according to claim 6, characterized in that the tough, elastic material (18) of the ver Wear layer or plate (8) is designed as a perforated plate and has openings (9) in which complementary geometric bodies (7) made of a highly wear-resistant material are received in a positive and non-positive manner.

8. Mill partition according to one of claims 6 or 7, characterized in that the wear layer or plate (8) is a tough, elastic rolled steel plate (18) and in the openings (9), which are circular and arranged regularly, cylinder sections as geometric Body (7) are included.

9. mill partition according to one of claims 6 to 8, characterized in that the geometric body (7) are block-like or block-like and after receiving them in the openings (9) of the tough, ice-cream layer or plate (18) an upper projection have and extend with a base (12) up to the first layer or support plate (5) designed as a supporting structure.

10. Mill partition according to one of claims 6 to 9, characterized in that the geometric body (7) are made of a metallic material, a high-alloy steel, a sintered metal or a ceramic or metal-ceramic material or a combination of these materials.

11. Mill partition according to one of claims 6 to 10, characterized in that the geometric bodies (7) are fastened in the tough, elastic layer or plate (18) by pressing, gluing or soldering.

12. Mill partition according to one of claims 6 to 11, characterized in that the wear layer or plate (8) has regularly arranged and almost identical geometrical bodies (7).

13. Mill partition according to one of the preceding claims, characterized in that the wear layer or plate (8) is arranged at least on the surface facing a grinding chamber (15) of a partition plate (3).

14. Mill partition according to claim 1, 10 to 13, characterized in that the partition plates (3) have a support layer or plate (5) made of a tough, elastic material and geometric body (7) made of a wear-resistant material and that in the area of geometric body (7) a wear layer (8) is formed.

15. Mill partition according to claim 14, characterized in that the geometric body (7) made of highly wear-resistant material with a protrusion in blind holes as complementary bores (9) of the carrier layer (5) are arranged positively and non-positively.

16. Mill partition according to one of claims 1 to 5, characterized in that the plate-shaped geometric body covers the entire surface of the carrier layer (5) and consists of a composite material with a welded tungsten carbide wear layer.