DD240338A1 - ROLLER COAT AS PANZERUNG FOR GRINDING ROLLERS - Google Patents

Abstract

The invention relates to a roll shell as armor for grinding rollers, in particular of Waelzmuehlen. The aim and object of the invention is to increase the service life of the roll shell with uniform wear of the roll shell over its entire width. According to the invention this is achieved in that the roll shell of the grinding rollers is divided into at least two rings arranged close to each other with different hardness and with the same or different width, wherein the Materialhaerte of the rings of the roll shell increases from the Mahlschuesselachse towards Mahlschuesselrand. Fig. 1

Description

The invention will be described with reference to a conically executed roll mantle. The invention can be used analogously for differently shaped roller profiles.

The roll shell formed as wear protection for the grinding rolls 3 for rolling mills consists of at least two rings 1 and 2. According to the bearing capacity of the material bed formed on the grinding path of the grinding table, the rings 1 and 2 have different material hardnesses. The grinding ring 1, which acts in the direction of the grinding bowl edge of the grinding table on the grinding bed, consists of a highly wear-resistant material, since the stress of the roll shell in this area is greater than that of the ring 2 in the direction of the grinding bowl axis as a result of occurring at Mahlschüsselrand high packing density of the material bed , In order to achieve a uniform wear over the entire width of the roll shell, the ring 2 has a lower hardness.

The number and the width of the rings depends on the load and is designed so that the wear over the roll shell width is approximately equal.

The rings 1 and 2 are clamped together on the conical grinding roller 3 by means of fastening screws 4 and a pressure ring 5, so that the rings 1 and 2 are pressed tightly against each other and an entry of material between the rings

is prevented. ,

According to Figure 2, a variant of the attachment of the rings is shown.

The advantages of the solution according to the invention are that with the use of wear-equivalent materials, the original Mahlspaltform is maintained over a longer period of use, so that throughput losses are reduced by scheduled Mahlspaltkorrekturen. Due to the use of different material hardnesses for the roller casing, the wear is adapted to the grinding process, so that a longer service life of the roll mantle overall can be achieved.

There is also the possibility of saving operating costs by making better use of cost-intensive wear materials. In the case of large building units, the division of the roll mantle according to the invention has the advantage of greater casting safety in the manufacture of the roll mantle.

Another advantage of the solution according to the invention is that the even wear of the roll shell over the entire width turning of the grinding rolls, to achieve a uniform wear, is superfluous, which in turn costs are saved.

Claims (2)

Invention claim: Roll shell as armor for grinding rolls of Wälzmühlen, characterized in that the roll shell is divided into at least two closely spaced rings of different hardness and with the same or different width, wherein the material hardness of the rings of the roll shell increases from the grinding bowl axis toward Mahlschusselrand. For this 1 page drawings Field of application of the invention The invention relates to a roll shell as armor for grinding rollers, in particular Wälzmühlen. Characteristic of the known technical solutions In the processing of granular material by means of roller mills, the wear of the roll mantle over its width is uneven. This situation is related to the different packing density or carrying capacity of the grinding bed. In particular, such areas of the roll shell show a high degree of wear, which overroll grinding bed zones with particularly high load-bearing capacity. In principle, this finding applies to all profile shapes of the roll shells. When kegligen roll shell z. B. is directed to Mahlschüsselrand diameter range by wear of particularly high intensity, which lead to the formation of a groove-shaped depression, characterized. On the other hand, the diameter range directed towards the grinding bowl axis wears out considerably more slowly, since the grinding bed in this zone only begins to condense as a result of the rolling stress. The stress differences across the width of the roll shell thus lead to impairment of Mahlspaltgeometrie. The wedge-shaped narrowing in the initial state grinding gap changes with increasing wear its profile to the effect that the gap narrowing is reduced with simultaneous reduction in throughput. A correction of the milling gap shape by adjusting the grinding gap, i. by pivoting the Mahlpendels towards Mahlschüssel, but only to a limited extent possible, because there is a risk that the roller in the small diameter range already touches the grinding path before the desired gap narrowing comes about. The loss of the optimum grinding gap profile and the imminent risk of metallic contact between the grinding track and the roll shell currently signal the necessity of a roll shell change. Furthermore, it is known to design the wear-resistant roll shell so that it can be turned on entry of a certain wear, so that the initially little worn roll shell surface in the second Einsätzphase überrolt the Mahlbettzonen with high load capacity. This ensures that the roll surface area is worn almost uniformly over its entire width. The disadvantage of the installation of the roll mantle in mirror image position is that the preparation of the bearing and seat surfaces of the roll mantle require precise machining so that the roll mantle sits even after turning stress-free on the bearing surface of the grinding rolls. In addition, a turning of the roll shell is associated with increased workload and costs. · Object of the invention The aim of the invention is to increase the service life of the roll shell for grinding rolls and to reduce the different wear over the Mahlbahnbreite of the rolls, thereby reducing throughput losses during milling of the material, also an additional work by turning the roll shell after wear is to be avoided , Explanation of the essence of the invention The object of the invention is to make the roll shell as armor for the grinding rolls so that over the entire width uniform wear of the roll shell during comminution of the material takes place. According to the invention this is achieved in that the roll shell of the grinding rolls is divided into at least two rings having a different hardness of the material. The roll shell ring, which acts in the region of the grinding bowl axis on the material bed with lower packing density, consists of cast materials with low to medium hardness, while the roll shell ring, which acts in the vicinity of the grinding bowl edge on the material bed with higher packing density, consists of a highly wear-resistant material. Depending on the load, the roll mantle, the rings are made in the same or unterschieblicher width. The roll shell rings are arranged close to each other, so that no material can get between the rings during the crushing process. embodiment The invention will be explained in more detail with reference to an embodiment. In the accompanying drawings shows 1 shows a side view of the roll shell according to the invention in section. 2: a variant of the solution according to the invention. '.