DE565287C - Hammer mill - Google Patents

Description

In order to achieve a certain degree of fineness of the grinding, it is with the known ones Hammer mill constructions required to keep the gaps in the discharge grates narrow or the grinding track with small holes Form sieve plates. Here the disadvantage arises that the mill, especially when the material is moist, easily clogged. But the mills also have the disadvantage of crushing dry material on that, in order to be able to guarantee sufficient comminution, they should have a large one Grind part of the good to the finest dust unnecessarily. You require one here extremely high power requirement; in addition, the volume output is significantly increased adversely affected.

In order to avoid these inconveniences, the grate bars of the discharge grate are according to the invention relatively far from each other, so that even oversized grain can fall through. One outside of the discharge grate in The fast moving, reciprocating sieve device arranged in the mill sifts it Good to the required extent, with the oversized grain via a transport device enters the grinding chamber again.

There are known designs of mills that use the sieve drum in one Return device for the oversized grain is installed; however, they are suitable because of the impossibility of matching the sieve drum performance to that of the hammer mill only for low mill outputs. If the sieve drum is rotated quickly, this will be Well not sifted out and the facility clogs up. With normal, slow rotation the sieve drum, the throughput rate is very low. Such mills are because of The inhibiting effect of the sieve drum is completely unsuitable for medium and large capacities. In the present invention In addition to the savings in performance, it comes down to the increase in performance ' the mill on. This is achieved by avoiding unnecessary fine grinding by the goods, passed through wide grate gaps, outside the discharge grate circumference is processed on a rapidly moving, reciprocating sieve with extremely high performance.

The drawing shows an embodiment of such a hammer mill.

Fig. Ι shows the hammer mill in cross section with built-in, in the direction of the arrow transversely moved sieve.

In principle, Fig. 2 shows the support of a sieve device designed as a spring sieve represent.

Fig. 3 shows a longitudinal section of the hammer mill.

The clubs α are suspended in a pendulum fashion on the club hub b, as is common practice. The mill has a preliminary grate c and a crushing wall d . Both can be adjusted and are easily exchangeable. To protect against the risk of breakage (if iron parts penetrate into the grinding chamber), the discharge grate is supported and resilient

adjustable. A sieve / is provided under the discharge grate, which is either moved quickly back and forth in guides g on rollers Ji in the direction of the arrow, sideways, or, as shown in Fig. 2, supported or suspended on springs i , its rapid reciprocating motion Movement in the direction of the arrow. Fig. 3 shows a simple,

to slowly rotating cell wheel / shown. This brings the oversized grain back into the grinding chamber via the slide; Of course, any conveying device can be selected here. In order to keep the last part of the grinding chamber free for this oversized grain, the inlet connection I can be arranged to the side, as shown in this figure. Can the mill have a blower to remove the dust or, when grinding coking coal, the finest material enriched with fiber coal before the feed? " have, which sucks this dust or the carbon fiber. A deflector plate η serves to protect the coarser grain from being sucked off. These auxiliary devices can optionally be driven with the interposition of gears from the hammer mill shaft or from another point.

If it is a question of using this hammer mill as a mixing mill as well, then so the mixing device is expediently directly below the rapidly moving one and moving sieve, since it is not a matter of indifference whether the one to be comminuted and the material to be mixed after comminution via chutes or other conveying devices a mixing device is supplied or whether that falling through the sieve and accordingly Material distributed over the entire surface is directly grasped by the mixing device and thoroughly mixed together. However, this arrangement of the mixing device does not belong to the invention.

The sieve and the mixing device located underneath, as well as part of the discharge grate, can form an assembly which can be accommodated in the common frame 0. This frame can be moved out so far on the slideway p of the mill housing in a known manner that worn parts can easily be replaced. There is also the possibility of swiveling the frame after it has moved out, whereby the rollers q move into position q ' . Before the frame is extended, the sieve / in the guide g is swiveled upwards.

In the hammer mill according to the invention, the feed material passes between the preliminary grate c and the crushing wall d and is pre-broken here so that the pieces get into the grinding chamber and are grasped and crushed here by the beaters α. After the comminution, the material falls onto the rapidly moving, reciprocating sieve / through which the fine material falls while the

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gen ,, um..wiadfion ^ die: grinding chamber to be abandoned for further comminution. When the "fine goods" fall through, the finest dust can be sucked off by means of the fan.

The hammer mill according to the invention has, as already indicated, compared to known ones Constructions significant advantages in that they are at relatively low Effort high performance and a size reduction up to the desired grain size enables without the unnecessary fine grinding of the rest of the product that would otherwise occur.

Claims (4)

Patent claims: 1. Hammer mill with moved outside of the discharge grate Sieve and return device for the oversized grain, characterized in that the outside of the discharge grate Sieve is designed as a rapidly moving, reciprocating sieve device. 2. Hammer mill according to claim 1, characterized in that the movement of the sieve transversely to the hammer mill axis with guides through the inner mill frame. 3. Hammer mill according to claim 1, characterized in that the sieve in known Way is supported by spring supports. 4. Hammer mill according to claim 1, characterized by the arrangement of a Cell wheel as a return device on one face of the mill, to which the oversized grain falls from the sieve. 1 sheet of drawings