DD258325A3 - METHOD OF INFLUENCING THE FINISHED PRODUCT IN CUTTING IN ROLLING MILLS - Google Patents

Abstract

The invention relates to a method for influencing the grain size distribution of the finished product, which is produced in Waelzmuehlen with inner or outer material cycle. The aim of the invention is to influence the desired grain size distributions of the comminution products of rolling mills with constant technical-technological parameters while minimizing the energy expenditure. The essence of the invention is that the ground material is promoted depending on the position and geometry of the rearrangement device and certain transport speed with constant technical-technological parameters once to the outside over the Mahltellerrand or the other inward under the following Waelzkoerper. The rearrangement device, preferably designed to be plowsharp-like, is associated with at least one, but usually each roller body.

Description

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Field of application of the invention

The invention relates to a method for influencing the particle size distribution of the finished product, which is produced in Wälzmühlen with inner or outer material circulation.

Characteristic of the known technical solutions

It is known that the usability properties of ground substances are essentially determined by their granulometric properties. '

The desired properties can be adjusted in the previously known Wälzmühlen with inner material cycle essentially by the variation of the contact pressure of the grinding rollers, the Staurandhöhe, the throughput, the Mahltellerdrehzahl, the Sichtluftstromes and the classifier speed. In roller mills with external material circulation essentially influence the contact pressure of the grinding rollers, the Staurandhöhe, the throughput and the Mahltellerdrehzahl and the setting of the classifying the particle size distribution of the crushed product. This means that in both variants with constant technical-technological parameters (contact pressure, grinding table speed, throughput), of which the size reduction process is significantly dependent, the particle size distribution is determined decisively by the setting of the classifier.

With the previously known loosening device (DD-WP 205079), the aim is to destroy the packing structure of the compacted material to be ground after each rolling element, relocate the material to be ground and stirred up, but without allowing a targeted and necessary Korngrößenverteilungsbeeinflussung or describe.

NachDE Auslegeschrifti 507 579 a device is described, which is used as a control element for power control of Wälzmühlen constant throughput. The described visual effects refer to a noticeable increase in performance with the same energy requirement. Although the arrangement of the device realizes visual effects, but in the form shown is not available for measures to influence the grain band.

Object of the invention

The aim of the invention is to influence desired particle size distributions of the comminution products of roller mills with constant technical-technological parameters while minimizing the energy expenditure.

Explanation of the essence of the invention

The invention is based on the technical object of providing a method for influencing the particle size distribution of the finished product during comminution in rolling mills.

According to the invention the object is achieved in that the ground material depending on the position and geometry of the rearrangement device and certain transport speed with constant technical-technological parameters once promoted to the outside on the Mahltellerrand or the other inward under the following rolling elements

The rearrangement device, preferably designed like a ploughshare, is associated with at least one, but usually each rolling element.

If the material to be ground is transported to the outside and thereby dispersed, the Sichtluftstom carries out the sufficiently fine ground material.

As a result, a ground product with a significantly lower proportion of fine grain can be generated energetically favorable.

If the ground product is conveyed inwards, then the material to be ground is subjected to repeated favorable conditions under conditions of reduced size and it is possible to produce fine grains with lower energy.

The same result can be achieved by varying the transport speed of the claimed Mahlgutbettes given position and geometry of the rearrangement device.

Since roller mills are designed with a constant grinding table speed, three-phase short-circuit motors are generally used. By means of frequency control, stepless speed control in the desired range can be retrofitted to existing drive solutions without replacement of the motors.

embodiment Embodiment 1

Limestone is crushed in a semi-technical roller mill with an internal material circulation. The roller mill operates at a throughput of 50kgh ~ ¹ . With constant technical-technological parameters (contact pressure, grinding table speed, throughput, classifying air flow, etc.) can be produced by the incorporation of a rearrangement with certain geometry and position at the corresponding transport speed of the ground material a crushed product with less Feinstkorn. With an upper particle size of the comminution product of 355μηη the proportions smaller than 30 μηη and 90μηη can be reduced by 10%

 The specific energy demand decreases by 60%.

Embodiment 2

In the same roller mill (as in embodiment 1) is extremely fine limestone flour produce energetically favorable. With the same technical-technological parameters is the incorporation of the rearrangement with certain geometry and position at the corresponding transport speed of the ground material at the same residue at 90 μιη of 20%, the proportion less 30μπι of 66% to 73% and less 10μπι from 35% to 48 % elevated.

The specific energy requirement can be reduced by 45% by installing a specific rearrangement device with a finer end product.

Embodiment 3

In a roller mill, a preferably ploughshare-like rearrangement device 2 is installed immediately behind one or more rolling elements 1.

At a constant Mahltellerdrehzahl (transport speed), it is possible by rotating the device about the axis 3 in the direction a to minimize the separation of the fine material from the grain collective and relocate the Good fed to the next rolling element to the stress.

By rotation of the rearrangement device in the direction b, the claimed grinding stock is sighted intensively in the region of the nozzle ring before the next stress and freed from fines.

With constant adjustment of preferably pflugscharähnlich designed rearrangement is by reducing the speed of the grinding table on the frequency-controlled three-phase motor (transport speed) minimizing the sighting of the grain collective and increased supply to re-stress under the rolling element taking place possible. When increasing the speed of the claimed regrind is increasingly guided in the area of the nozzle ring and freed from fines claimed again.

Claims (1)

claims: Claim 1 Method for influencing the particle size distribution of the finished product during comminution in roller mills with two or more stationary rotating rolling elements and a horizontally rotating MahlteHer to which the material is fed centrally or in front of the rolling elements, wherein a device for rearrangement and Aufwerbelung the ground material is attached, characterized in that the rearrangement takes place with a plowshare-like device, which promotes the grinding stock, optionally to the center of the grinding table or to the edge of the grinding table. Claim 2 A method according to claim 1, characterized in that the direction of the promotion by a rotation of the pflugscharähnlichen device and / or a change in the rotational speed of the grinding table is variable.