DE4440728C1 - Agitation=type rotary mill - Google Patents

Abstract

The mill is particularly of the ball type, having a rotary stirring mechanism in a bearing inside a vertical vessel and a continuous supply to the bearing of an agent forming a film between the bearing surfaces. The union (11) supplying the agent also provides a separate supply for a dispersing agent, while the raw suspension to be ground is delivered via a separate inlet (4) in the vessel bottom. There is a cylinder (8) open to the underside at the bottom end of the stirring shaft, and in which a cylindrical bearing and guide member (10) on the vessel bottom fit. The guide member contains the union for the dispersing agent.

Description

The invention relates to an agitator mill, preferably Agitator ball mill, according to the preamble of claim 1.

In the usual vertical agitator ball mills of this type the agitator shaft only at its upper end, outside of the meal container, stored. The agitator shaft therefore hangs freely down into the grinding container. For larger mills with one Height of 5-10 m, for throughputs of about 20 tons each Hour, the problem arises that the agitator in uncontrolled gated vibrations device; there are lateral deflections or pendulum movements, the agitators the container wall touch, causing damage and malfunction.

To avoid this, it is from the German interpretation 1 272 689 also known, on the bottom of the grinding container Install bearings in which the lower end of the agitator shaft is stored and the suspension to be ground by the  Bearing is entered into the grinding container. The between flowing through the mutual bearing surfaces to be ground Suspension thus serves as a lubricant and - by building up a corresponding hydro-static pressure between each other overlying storage areas - also as the supporting medium of the Camp.

However, disadvantages have emerged in operation. Especially approaches occur, in particular blockages of the bearing.

Accordingly, the invention is based on the object Mill of the generic type with storage create with which the wave additionally stored inside the grinding container or is led, but the previous difficulties and Disruptions in operation can be avoided.

The solution to this problem is in the labeling section of the Claim 1 specified.

According to the invention, the whole is not as before grinding raw suspension through the lower bearing of the agitator passed through, but as a resource for this Bearing becomes a dispersant in and through the bearing Bearing passed into the grinding container. For the supply line the raw suspension to be ground is a separate inlet on provided lower end of the grinding container.

It is also previously known to add dispersant to the mill enter, but so far the dispersant was together with of the raw dispersion to be ground is fed into the mill. According to the invention, however, the dispersant is separated from the Raw suspension entered through the lower shaft bearing, where it serves as a resource for this camp.  

In a further embodiment of the invention can also at the upper end of the grinding container a bearing for the agitator shaft is provided be, which also with a connection for a disperser medium - or another company compatible with the regrind means for the bearing - is provided. Since the bearings of the stirrer factory shaft are all provided within the grinding container, the distance between the bearings is correspondingly smaller, so that the shaft can be thinner and lighter and the agitator less tends to vibrate or the natural vibration frequency above the usual operating speeds, so that it is not to Anre vibrations.

In particular, this or each can be pre-inside the mill see, with a dispersant or similar equipment operated camp can be designed arbitrarily. As a resource a part of the ground fine can also be used for the bearing or bearings suspension or water can be used.

Advantageous embodiments of such a bearing are in the Claims 2 and 3 indicated and are subsequently based on the Description explained in more detail.

Fig. 1 shows schematically, in longitudinal section, a vertical agitator ball mill, the agitator shaft is supported according to the invention at the lower end;

Fig. 2 shows an enlarged view of the lower part of the mill with a lower bearing according to the invention.

The agitator ball mill consists of a vertical, cylindri's grinding container 1 , in which an agitator is rotatable. The agitator consists of the agitator shaft 2 , which is equipped with annular or radially extending agitators 3 . The raw suspension to be ground is fed through an inlet pipe 4 at the lower end of the grinding container 1 ; at the upper end of the grinding container 1 , a sieve 5 is schematically provided as a separator in front of which an outlet pipe socket 6 is provided for the finely ground suspension.

At the lower end, a bearing 7 for the agitator shaft is provided, consisting essentially of a bearing part 8 moored on the agitator shaft 2 and a bearing part 10 moored on the bottom 9 of the grinding container.

The moored bearing part 10 is provided according to the invention with a connection 11 for a dispersant which flows between the two bearing parts into the mill and thereby serves as an operating medium for the bearing, thus lubricating the bearing or a supporting layer between the two bearing parts 8 , 10 forms in the manner of a hydrostatic bearing.

It is known to add a dispersant to the mill. So far, however, the dispersant was too mah together with the loin raw suspension entered into the mill. According to the Erfin dung that is anyway for the grinding process as well as for the finished product required dispersant separately, through the warehouse entered into the mill, so that it is first as Be for the warehouse.

The structure of the camp in detail is arbitrary. The bearing shown in FIG. 2 has proven particularly effective, consisting of a cylindrical bearing part 8 , which - with the opening facing downwards - is screwed tightly to the lower end of the agitator shaft 2 , and into which a likewise cylindrical bearing part 10 projects with play, which is moored on the bottom 9 of the grinding container.

This inner bearing part 10 has an inner tube piece 12 , through which a hose connection 11 is passed, which is screwed to the bottom of the inner bearing part 10 . This piece of tubing is used to enter the dispersant required - first as operating fluid in the warehouse and then, as usual, inside the mill. This dispersant forms a base layer between the two bearing parts, via which the bearing forces are transferred from the agitator shaft to the bottom of the grinding container.

Between the inner pipe section 12 and the cylinder wall of the inner bearing part 10 , a rubber-elastic cylinder ring 13 is inserted, whereby the bearing receives a large radial flexibility, which in turn vibrations of the agitator shaft are caught and damped.

The pipe section 12 is fastened to the bottom 9 of the grinding container by means of weld seam 14 . On the bearing part 10 at least one approach 15 is provided, which engages in a recess 16 on the bottom 9 , whereby the bearing part 10 is movable relative to the bottom 9 in the radial direction, but is fixed in the circumferential direction.

Approx. 1% dispersant is required for the finished product an output of, for example, 20 tons per hour of finished pro so it produces 200 kg of dispersant per hour.

Reference list

1 grinding bowl
2 agitator shaft
3 stirring elements
4 inlet ports
5 sieve
6 outlet ports
7 bearings
8 bearing part
9 floor
10 bearing part
11 hose connection
12 pipe section
13 Rubber-elastic cylinder ring
14 weld seam
15 approach
16 deepening

Claims (3)

1. agitator mill, preferably agitator ball mill, with a grinding container in which an agitator is rotatable, a bearing for the agitator shaft being provided at least at one end inside the preferably vertically arranged grinding container, which has a connection for the constant supply of a between the bearing surfaces Film-forming medium is provided, characterized in that the connection ( 11 ) is provided for the separate supply of a dispersing agent, while a separate inlet ( 4 ) is provided at the lower end of the grinding container for the supply of the raw suspension to be ground. 2. Agitator mill according to claim 1, characterized in that a downwardly open cylinder ( 8 ) is attached to the lower end of the agitator shaft, in which a cylindrical bearing and guide element ( 10 ) attached to the bottom of the grinding container engages, which is provided with the connection ( 11 ) for the dispersing agent. 3. Mill according to claim 1 or 2, characterized in that a tube piece ( 12 ) is provided within the guide and bearing element ( 10 ) which is stuck to the bottom of the grinding container, the annular space between the tube piece and the cylinder being made of a rubber-elastic material ( 13 ) is filled out.