NL9000739A - HAMMER MILL WITH RADIALLY ADJUSTABLE SIEVE. - Google Patents

Description

Hammer mill with radially adjustable sieve shroud.

The invention relates to a hammer mill with radially adjustable sieve shell, which is used for crushing grain fruits, long-fiber and chopped raw feeds, Combi-Corn-Mix (CCM) and other products in the agricultural food industry.

Hammer mills are known which consist of a rotor and beaters suspended therefrom, of which the stroke circle comprises the sieve jacket for the most part and thereby forms the grinding space. The hammer mills are fed in the high-power types in the center, radially from above, and in the low-power types, in part also axially at the height of the rotor shaft.

There is a defined gap between the stroke circle and the sieve shroud, which arises from the difference of both rays. The size of the gap is changed during wear of the hammer mill by wear of the beater.

Optimal gap sizes are created depending on the sieve holes and the product. The currently known machines with a constant gap are built in such a way that after a short run-up time the machine works optimally and after strong wear of the beaters, the quality of the end product deteriorates and the specific energy required increases, so that with relatively little knock wear, a change in the rotor or a beater change becomes necessary. In addition, it is not possible to adapt the working gap to a specific product.

As a result, known hammer mills only work for a short period of time and for a very limited number of products with an optimum distance between the impact circle and the sieve jacket.

The object of the invention is to provide a hammer mill, in which, by using a radially adjustable sieve shroud, the gap between the stroke circle of the beaters and sieve shroud can be adjusted within certain limits by about 50% of the rotor circumference. Due to the constant curvature of the screen casing, a constant gap width cannot be adjusted over the entire circumference. Since the gap in the area below the rotor axis is the most intensive, the gap is sufficiently uniform there.

This makes it possible to adjust the gap width between beaters and sieve shroud to the product within certain limits and to compensate partly for whipper wear.

The object of the invention is to provide a hammer mill, wherein the sieve casing can be adjusted radially towards the rotor shaft. At the same time, the sieve-jacket halves must rotate inwards in the direction of the rotor when the jacket moves in the direction of the rotor, so that a relatively constant gap for the beater is formed, especially in the lower segment of the sieve-jacket halves.

According to the invention, this object is achieved in that the screen jacket consists of two halves which surround the rotor and which can be moved radially as a whole or with each screen half separately. If the bottom sieve holder moves towards the rotor, these halves must also rotate towards the rotor.

According to the invention, this is achieved in that the screen halves at the upper end are held by bolts in a long-hole guide. When the lower sieve holder is moved upwards towards the rotor, the upper sieve ends are turned towards the rotor according to the guide. After adjusting the gap, the top strainer ends are clamped to prevent vibrations. The design of the screen halves can be variable. Strong sieve plates can be attached directly. Thin sieve plates are supported by window and sieve guide. In this case, the screens with frame and sieve guide must be moved. In addition, the sieve casing can also be divided into two parts of different sizes.

The movement can be stepless, because the bottom screen holder rests in a guide and is adjusted via a spindle or eccentric.

A stop has been provided to prevent the screen from hitting new beaters in its stroke circle.

The invention is explained in more detail below with reference to an exemplary embodiment. The accompanying drawings show in

Fig. 1 a section of the hammer mill,

Fig. 2 is a section along line A-A of FIG. 1,

Fig. 3 is a section along line B-B of FIG. 1,

Fig. 4 is a cross section of the hammer mill with screen plate and screen frame.

In FIG. 1 it can be seen that the sieve jacket 2 surrounds the grinding space 3 by about 75%. The sieve halves are mounted rotatably on bolts 12 in the lower sieve holder 5. The bolts can be moved axially via levers and allow a quick change of sieves (see Fig. 2). The sieves consist of sieve plates, which are thicker than 3 mm, which eliminates the need for a support frame. Welds 4 with bore are provided at the sieve halves. The bolt 12 of the bottom screen holder 5 is arranged in the weld 4, whereby the screen is secured radially and axially. The left half of the sieve is shown in the starting position, the right half shows the adjusted sieve.

Welds 4 with bore are also attached to the upper screen end. A threaded stud 6 protrudes from the inside through the weld bore and the long hole guide 8 of the side wall 9 to the outside. The nut screwed onto the thread tap serves to clamp the upper sieve end (see Fig. 3). The bottom screen holder 5 rests in a guide, consisting of two guide bolts. The radial adjustment of the bottom screen holder 5 is effected via a spindle 7, which is operated via a socket wrench.

The nuts must be loosened from the top strainer ends for adjustment. By rotating the spindle 7, the bottom screen holder 5 in the long hole guide 8 is rotated radially. The screen halves thus perform a vertical movement.

It is also possible to design the bottom sieve holder 5 in part and thereby adjust both sieve halves separately. Furthermore, the sieve casing 2 can consist of two or more sieve parts of different sizes. The movement of the sieve parts takes place radially in the holder.

In FIG. 4 shows the use of sieve halves from a thin sieve plate, which rest on a sieve frame 10 and are clamped against an inner guide 11. This unit can rotate completely in the bottom screen holder 5. The adjustment is made in accordance with Fig. 1 described.

Claims (3)

1. Hammer mill with radially adjustable sieve shell, preferably for crushing grain fruits, long or pre-chopped raw feed, CCM and other products from the agricultural and food industry, consisting of a rotor with hinged beaters, characterized in that the rotor (1 ) surrounding sieve casing (2), which forms the grinding chamber (3), consists of two halves and both sieve halves are pivotally mounted in the radially adjustable lower sieve holder (5), resting on its upper ends by welding (4) bolts (6) are guided through long-hole guides (8) arranged in the side walls (9) and, when the lower single-module screen holder (5) moves vertically, the screen halves are forced towards the center of the rotor are moved in the direction of the beater's stroke circle. 2. Hammer mill according to claim 1, characterized in that the lower sieve holder (5) consists of two independently movable parts assigned to the sieve halves, and that the adjustment of both sieve halves is optionally done separately. 3. Hammer mill according to claims 1 and 2, characterized in that the sieve jacket (2) consists of two or more sieve parts of unequal size.