Agitating mill
An agitator mill, in particular an agitator bead mill having a mill housing, in which an agitator shaft, preferably bearing agitator elements, circulates in such a way that a grinding chamber is configured between the agitator shaft and the mill housing, and into the chamber the grist is fed, transported by a fluid carrier substance, as a rule in the form of a suspension, wherein the grinding chamber is partially filled with grinding media, which are set in motion by the circulating agitator shaft and thereby the grist, carried through the grinding chamber by a fluid carrier substance, is crushed, wherein the grist, transported by the fluid carrier substance, is discharged together with the carrier substance through a sieve, which retains grinding media that arrive as far as the area of the sieve, wherein the sieve consists of several sieve elements arranged one after the other along the longitudinal axis of the agitator mill, the sieve elements being penetrated in parallel manner, with their surfaces flowing from the grinding chamber, and extend diagonally or radially to the axis, around which the agitator shaft circulates.
1 . An agitator mill comprising:
a mill housing,
an agitator shaft that circulates within the mill housing, and
a grinding chamber provided between the agitator shaft and the mill housing, the grinding chamber being configured to receive a grist, wherein the grist is transported by a fluid carrier substance in a form of a suspension within the grinding chamber,
wherein the grinding chamber is partially filled with grinding media, the grinding media being set in motion by the circulating agitator shaft to crush the grist that is transported by the fluid carrier substance,
wherein the grist is discharged together with the fluid carrier substance through a sieve, the sieve being configured to retain the grinding media within the grinding chamber,
wherein the sieve comprises several sieve elements arranged in parallel one after another along a longitudinal axis of the agitator shaft, the sieve elements having surfaces through which the grist and the fluid carrier substance penetrate, wherein the surfaces extend diagonally or radially relative to the longitudinal axis,
wherein at least a portion of the agitator shaft is hollow, and wherein the sieve is arranged in a sieve chamber configured in the hollow portion of the agitator shaft.
2 . The agitator mill according to claim 1 , wherein each of the sieve elements is arranged at a front surface of at least one sieve carrier, the at least one sieve carrier having a peripheral side that is closed, wherein each of the sieve elements is constructed of steel.
3 . The agitator mill according to claim 2 , wherein the at least one sieve carrier comprises a plurality of sieve carriers, each of the plurality of sieve carriers having two front surfaces, wherein each of the two front surfaces is configured by one of the sieve elements.
4 . The agitator mill according to claim 1 , wherein the agitator mill comprises a plurality of sieve carriers, each of the plurality of sieve carriers includes an outer ring that defines a closed peripheral enclosure surface.
5 . The agitator mill according to claim 4 , wherein:
the outer ring is constructed of ceramic, or
the peripheral enclosure surface includes a coating to reduce abrasion.
6 . The agitator mill according to claim 4 , wherein each of the plurality of sieve carriers includes a hub and spokes extending radially out from the hub sleeve, the spokes connecting the outer ring to the hub sleeve.
7 . The agitator mill according to claim 6 , wherein the hub of at least one of the sieve carriers includes at least one discharge opening for the fluid carrier substance and the grist.
8 . The agitator mill according to claim 6 , further comprising a drain tube, wherein the sieve carriers are mounted on the drain tube, wherein the drain tube includes at least one discharge opening through which the fluid carrier substance and the grist flow out of the sieve carrier into the drain tube.
9 . The agitator mill according to claim 8 , wherein the sieve carriers are carried by the drain tube, and wherein the sieve carriers are configured to be rotated with the drain tube.
10 . The agitator mill according to claim 1 , further comprising at least two sieve carriers arranged along the longitudinal axis, each of the at least two sieve carriers having one of the sieve elements.
11 . The agitator mill according to claim 1 , wherein the grinding chamber is connected by rotary openings with the sieve chamber, wherein main extending axes of the rotary openings run parallel to the longitudinal axis.
12 . The agitator mill according to claim 1 , wherein the sieve elements rotate with the agitator shaft, wherein individual sieve openings of each of the sieve elements have a greater diameter than the grinding media on a side of the sieve element where the fluid carrier substance and the grist flow from the grinding chamber.
13 . The agitator mill according to claim 12 , wherein each of the individual sieve openings taper in a funnel shape, in an inward direction.
14 . The agitator mill according to claim 1 , wherein the sieve chamber and the sieve are rotatable.
15 . An agitator mill comprising:
a mill housing,
an agitator shaft that circulates within the mill housing,
a grinding chamber provided between the agitator shaft and the mill housing, the grinding chamber being configured to receive a grist, wherein the grist is transported by a fluid carrier substance in a form of a suspension within the grinding chamber,
a plurality of sieve carriers, each of the plurality of sieve carriers includes an outer ring that defines a closed peripheral enclosure surface, each of the plurality of sieve carriers includes a hub and spokes extending radially out from the hub sleeve, the spokes connecting the outer ring to the hub sleeve, and
a drain tube, wherein the sieve carriers are mounted on the drain tube, wherein the drain tube includes at least one discharge opening through which the fluid carrier substance and the grist flow out of the sieve carrier into the drain tube,
wherein the grinding chamber is partially filled with grinding media, the grinding media being set in motion by the circulating agitator shaft to crush the grist that is transported by the fluid carrier substance,
wherein the grist is discharged together with the fluid carrier substance through a sieve, the sieve being configured to retain the grinding media within the grinding chamber,
wherein the sieve comprises several sieve elements arranged in parallel one after another along a longitudinal axis of the agitator shaft, the sieve elements having surfaces through which the grist and the fluid carrier substance penetrate, wherein the surfaces extend diagonally or radially relative to the longitudinal axis,
wherein the sieve carriers are carried by the drain tube, and wherein the sieve carriers are configured to be rotated with the drain tube,
wherein the drain tube includes at least one compensation channel through which the fluid carrier substance and the grist are conveyed and discharged into at least one intermediate space, wherein each of the at least one compensation channel is configured as a tube that is disposed between the drain tube and the hub.
16 . An agitator mill comprising:
a mill housing,
an agitator shaft that circulates within the mill housing, and
a grinding chamber provided between the agitator shaft and the mill housing, the grinding chamber being configured to receive a grist, wherein the grist is transported by a fluid carrier substance in a form of a suspension within the grinding chamber,
wherein the grinding chamber is partially filled with grinding media, the grinding media being set in motion by the circulating agitator shaft to crush the grist that is transported by the fluid carrier substance,
wherein the grist is discharged together with the fluid carrier substance through a sieve, the sieve being configured to retain the grinding media within the grinding chamber,
wherein the sieve comprises several sieve elements arranged in parallel one after another along a longitudinal axis of the agitator shaft, the sieve elements having surfaces through which the grist and the fluid carrier substance penetrate, wherein the surfaces extend diagonally or radially relative to the longitudinal axis,
wherein the sieve elements rotate with the agitator shaft, wherein individual sieve openings of each of the sieve elements have a greater diameter than the grinding media on a side of the sieve element where the fluid carrier substance and the grist flow from the grinding chamber,
wherein each of the individual sieve openings taper in a funnel shape, in an inward direction,
wherein the funnel shaped taper of each sieve opening merges into a channel that has a diameter less than the diameter of the grinding media.
17 . An agitator mill comprising:
a mill housing,
an agitator shaft that circulates within the mill housing, and
a grinding chamber provided between the agitator shaft and the mill housing, the grinding chamber being configured to receive a grist, wherein the grist is transported by a fluid carrier substance in a form of a suspension within the grinding chamber,
wherein the grinding chamber is partially filled with grinding media, the grinding media being set in motion by the circulating agitator shaft to crush the grist that is transported by the fluid carrier substance,
wherein the grist is discharged together with the fluid carrier substance through a sieve, the sieve being configured to retain the grinding media within the grinding chamber,
wherein the sieve comprises several sieve elements arranged in parallel one after another along a longitudinal axis of the agitator shaft, the sieve elements having surfaces through which the grist and the fluid carrier substance penetrate, wherein the surfaces extend diagonally or radially relative to the longitudinal axis,
wherein the sieve elements rotate with the agitator shaft, wherein individual sieve openings of each of the sieve elements have a greater diameter than the grinding media on a side of the sieve element where the fluid carrier substance and the grist flow from the grinding chamber,
wherein the agitator mill further comprises separator plates, wherein each of the separator plates being disposed on an inner surface of one of the sieve elements at a downstream side of the individual sieve openings, so that a gap is configured between the inner surface of the sieve element and each of the separator plates, and wherein the fluid carrier substance and the grist must pass through the gap at a connection point of each of the individual sieve openings.
18 . The agitator mill according to claim 17 , wherein each of the separator plates has a plurality of openings, each of the plurality of openings having an axis that runs parallel to the longitudinal axis of the agitator shaft, wherein the plurality of openings of each of the separator plates and the individual sieve openings of a corresponding sieve element of the sieve elements are disposed at a distance from one another, as seen in a radial and/or in a peripheral direction, such that the fluid carrier substance and the grist must pass through the gap in order to flow out from the individual sieve openings through the openings of the separator plate.
19 . The agitator mill according to claim 17 , wherein the gap has a gap height which is at least 30% smaller than the diameter of a smallest grinding medium.