DD140656A1 - DEVICE FOR RESERVING THE GRINDERS IN GRANULAR BALL MILLS - Google Patents

Abstract

The invention relates to a device that prevents grinding media from being washed out of agitated ball mills. This device consists of a rotating disc, which is mounted on the agitator shaft of the mill at a certain distance from the lid and to which guide strips are attached. Any grinding media that are swept up over this disc are caught by the guide strips or the disc itself and thrown outward against the wall of the grinding container, where they fall back down. The device is used in agitated ball mills for the wet fine grinding of solids such as dyes or the like.

Description

VEB CHEMIEKOMBINAT BITTEEFELD Bitterfeld, March 26 , 1977

1898

Device for retaining the grinding media in stirred ball mills

Field of application of the invention

The invention relates to agitator ball mills for grinding and dispersing solids in liquids in the presence of grinding media whose diameter is less than 4 mm. These consist of a vertical grinding container and arranged therein rotating Eührorganen ₀ In particular, however, the invention relates to a device to retain the grinding media in the continuous discharge of the ground material. Such mills are mainly used for grinding of dyes.

Characteristic of the known technical solutions

When operating such Rührwerkskugelmühlen must be taken to ensure that the grinding media are retained in the mill and are not washed out with the millbase. It is known that this can be done by a Offensiebabtrennung-. Such systems have the disadvantage that it comes in the upper part of the grinding container for Trombenbildung and thus the unwanted incorporation of air in the millbase »

9 9 9 27 9 1898

In order to avoid the formation of droplets, therefore, closed agitator screw mills were constructed, in which the grinding media were removed from the millbase by friction gap separation or so-called gap sieves. In the separation of the friction gap, the uppermost disk is designed such that it has a small diameter in the conical constriction at the upper part of the grinding container Gap forms whose diameter is smaller than the diameter of the grinding media. Due to the wave fluctuations of the free-standing agitator shaft, there are difficulties in the operation and excessive wear of the separation system, similar difficulties arise in the Spaltsiebabtrennung. This is to be understood as a slotted screen rotating on a () hollow shaft. The sealing of the ffiahlraumes from the product outlet is made by a single-acting spring-loaded mechanical seal. Due to the imbalance of the stirrer shaft and the grinding discs, the sliding rings tilt and thus the sealing system fails (DL-PS.67 439, 86 975, DT-AS 1 242 078).

Object of the invention

The purpose of the invention is to develop a system for restraining the grinding media, which does not have the indicated defect and guarantees trouble-free operation of the stirred ball mills. This results in the task to make a meal -'''''körperabtrennsystem so that it is not affected in its operation by occurring wave vibrations and Mahlkörperverschleißerscheinungen.

Explanation of the essence of the invention

According to the invention, a device for retaining grinding media in agitating ball mills for wet fine grinding is obtained from a vertical round grinding container with stirrer shaft and stirrers mounted thereon, if on the stirrer shaft under the lid a round rotating disk with a diameter of 0 0 to 96 % of the grinding container interior diameter is arranged, which disc

1 mm to 10 mm high on the top, which eject the coming into the sphere of action of the disc grinding media outward, wherein the distance from the cover to the upper edge of the guide strips at least equal to at least ten times the Mahlfacher diameter corresponds to at least.

Such a device according to the invention operates in such a way that all of the agitator grinding elements which are forced upwards in the agitating mill are thrown outwards on contact with the pane and therefore can not reach the grinding stock outlet.

embodiment

The invention will be explained with reference to the drawings Fig. 1 and Fig. 2. The reference numbers mean:

1 stirrer shaft

2 round disc

3 grinding container lids

4 grinding containers

5 agitator (grinding disc)

6 guide strips

FIG. 1 shows a device according to the invention for retaining the grinding media in stirred ball mills by means of a disk with guide strips rotating on the agitator shaft, while FIG. 2 shows a possible arrangement of the guide strips. According to FIG. 1, the agitator ball mill device according to the invention consists of the disc 2 rotating on the agitator shaft 1 and the grinding container lid 3. The millbase is conveyed continuously into the grinding container 4 and comminuted by the agitators 5 rotating on the shaft in the presence of grinding bodies. The separation of the grinding media is effected by the centrifugal force of the rotating disk 2 and the guide strips 6.

The ground material is fed in the form of an aqueous suspension in the lower part of the grinding container 4 and flows continuously upward _e where it is detected by the stirring members 5 and · dea grinding media and crushed. The suspension then flows past the disc according to the invention. In doing so, individual grinding media are repeatedly torn. In the space between disc and De'ckel the entrained grinding media at any point with the guide strips or the disc itself come into contact Be and thus be hurled immediately to the wall of the grinding container 4, where they fall down. In this way, no grinding media can get to Mahlgutaustrag.

Claims (1)

-5- ι y y a / y 1898 Patentanspru ch Grinding device for retaining grinding media in stirred ball mills for wet grinding, consisting of a vertical round grinding container with agitator shaft and stirrers mounted thereon, characterized in that on the agitator shaft under the cover there is a round rotating disk with a diameter of 70 to 96%. of the Mahlbehälterinnenendurchmessers is arranged, which carries-on the upper side guide-plate about 1 to 10 mm high, which throw the coming into the sphere of action of the disk grinding media outward, the distance from the lid to the upper edge of the Leitstreifen at least one and a half times to ten times' of the grinding media diameter corresponds. , '' For this / f ^Seit0 drawing