Agitator mill

Details Agitator mill Agitator mill

1999-08-26

2001-07-17

Rosenbaum, Mark (Department: 3725)

Solid material comminution or disintegration

Apparatus

Loose grinding body comminutor

C241S172000

Reexamination Certificate

active

06260779

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an agitator mill.
2. Background Art
U.S. Pat. No. 4,496,106 teaches, in an agitator mill with a cylindrical agitator, to supply the grinding stock concentrically from below and to discharge it upwards through an annular gap separating device. Auxiliary-grinding-body circulation takes place by external recirculation, the auxiliary grinding bodies being again supplied to the grinding stock supply line, i.e. they are supplied to the grinding-stock receptacle centrically from below together with the grinding stock. Experience has shown that the circulation of the auxiliary grinding bodies is irregular in this case.
SUMMARY OF THE INVENTION
It is an object of the invention to embody an agitator mill with external auxiliary-grinding-body circulation, in which regular and stable circulation of the auxiliary grinding bodies takes place.
According to the invention, this object is attained in an agitator mill comprising a grinding receptacle, a cylindrical wall and a lid and a bottom of which define a grinding chamber to be filled with auxiliary grinding bodies; an agitator, which is disposed in the grinding receptacle and has an agitator shaft and agitator elements mounted thereon; a drive motor for driving the agitator in rotation about an axis; a grinding-stock supply line, which is disposed at least in vicinity to the lid or to the bottom and opens into the grinding chamber; a grinding-stock/auxiliary-grinding-body separating device, which is disposed at least in vicinity to the bottom or the lid and opens into a grinding-stock discharge line; and an auxiliary-grinding-body return line, which is separate from the grinding-stock supply line, and which comprises an outlet from the grinding chamber in the vicinity of the cylindrical wall and neighboring the separating device, and which comprises an inlet into the grinding chamber radial to the axis in vicinity to the agitator shaft and neighboring the inlet of the grinding-stock supply line in the direction of the axis. Surprisingly, especially stable auxiliary-grinding-body circulation can be found whenever the auxiliary-grinding-body return line discharges from the grinding chamber in a portion of higher local pressure and opens into the grinding chamber in a portion of partial local vacuum. The pressure difference between the outlet and the inlet of the auxiliary-grinding-body return line furnishes the power and thus the actuation for a continuous and regular return of auxiliary grinding bodies (together with part of the grinding stock) through the auxiliary-grinding-body return line. Due to the fact that the auxiliary-grinding-body return line and in particular the inlet thereof into the grinding chamber is separate from the grinding-stock supply line, the low pressure which forms in the proximity of the agitator shaft in the grinding chamber can arise at the inlet. Since the grinding stock is supplied by means of a pump through the grinding-stock supply line, a correspondingly higher pressure prevails there, which would oppose the described effect in the case of a common insertion of fresh grinding stock and returned auxiliary grinding bodies. The inlet of the auxiliary-grinding-body return line into the grinding chamber is situated on the one hand as close as possible to the agitator shaft radially to the axis of the agitator shaft and on the other hand at the end of the grinding chamber into which opens the grinding-stock supply line.


REFERENCES:
patent: 4739936 (1988-04-01), Stehr
patent: 5544825 (1996-08-01), Stehr
patent: 5624080 (1997-04-01), Stehr et al.
patent: 5758833 (1998-06-01), Kabbe

Affiliated with

Also associated with

Rating

Agitator mill does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Agitator mill, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Agitator mill will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2502621