DE9321229U1 - Lining for the mill door of a fan mill - Google Patents

Description

The invention relates to a lining for the mill door of a fan mill, consisting of an inlet slope, two side walls and an arched rear wall.

The mill door of a fan mill serves on the one hand as an inlet slope for the incoming coal flow, and on the other hand it is intended to provide access to the beater wheel. It is therefore designed in the shape of a housing with an inlet slope, two side walls and an arched rear wall. The mill door can be attached to hinges and remains connected to the mill housing when opened, or it can be mounted on rollers, is moved to the side and there is no

No more connection with the mill housing. Io

The entire fan mill is exposed to different temperatures. For safety reasons, the temperature in the mill housing may only reach a limit temperature of approx.

200*C. The temperature in the housing-shaped mill door is, however, about 2 to 3 times higher. These high thermal loads lead to large stress cracks in the walls of the door or to severe distortions. The

² ^ walls are so thick that a high level of material wear occurs in a short time. In order to avoid or reduce these phenomena, the mill doors are thermally insulated. It is known to attach insulating masonry or elastic insulating material to the housing wall and to cover it with wear plates.

ten (DD 137 890, DD 136 705). In this case, webs are attached to the housing wall with bolts and the wear plates are attached to these with corresponding tabs. When the plates are subjected to alternating loads, however, the plates come loose and fall into the mill. It is also known to attach the wear plates like roof tiles (DE 16 07 520). The disadvantage of this solution is the poor positional security of the plates and the high cost of

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repairs.

According to DE 10 99 826, the wear plates are secured using terminal strips. This requires a high level of manufacturing effort. In addition, this design can only be used for low insulation thicknesses.

To prevent the coal dust from getting behind the wear plates, cover strips are often welded onto one side of the plates. This has the disadvantage that

These can be lifted and torn off by welding on one side.

The initial equipment, but also the repairs, are very cost-intensive.

Another solution is to concrete the mill door on all sides and only cover the most wear-intensive areas with wear plates. The wear-resistant concrete used, mainly fiber concrete, is very expensive and the service life is not significantly increased compared to lining the entire walls with wear plates.

The invention is based on the object of lining a mill door consisting of an inclined inlet, two side walls and an ^arched rear wall in such a way that no distortions or scaling of the housing walls occur.

This is achieved according to the invention by attaching spacer bushings to the inlet slope and the side walls 30

and the walls are drilled through in the area of the spacer bushings, thermal insulation material is placed on the inlet slope and the side walls and covered with wear plates, the wear plates are attached to the wall from the outside with threaded bolts through the spacer bushings, spacer bolts are firmly inserted into the rear wall, thermal insulation material is placed on the rear wall and covered with

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wear plates are covered and the wear plates are attached to the spacer bolts.

The wear plates are placed on a front pin of the spacer bolts and held by retaining disks in a recess in the wear plates, with a clearance on all sides between the retaining disks and the wear plates. In a further development, the wear plates are arranged with expansion joints to one another, with the expansion joints being covered from the inside with cover plates that are held by stabilizing ribs attached to the wall.

The invention will be explained below using an embodiment

will be explained in more detail. The accompanying drawing shows: 15

- Fig. 1: a longitudinal section through the mill door

- Fig. 2: the upper part of the rear wall in section

- Fig. 3: the spacer bolt for fastening the wear

panels on the back wall

- Fig. 4: the fastening of the wear plates to the side walls and the covering of the expansion joints.

The mill door intended for lining consists of an inlet slope 1, two side walls 2 and an arched rear wall 7. The lining according to the invention

is carried out for the inlet slope 1 and the two side walls

2 in the same way. For this purpose, spacer bushings 3 are attached to the walls. The walls are drilled through in the area of the spacer bushings 3. Thermal insulation material 4 is placed on the inlet slope 1 and the rr side walls 2 and secured with

wear plates 5. The wear plates 5 are fastened to the wall from the outside with countersunk threaded bolts β through the spacer bushings 3 (see Fig. 4).

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Spacer bolts 8 are attached to the rear wall 7 of the mill door. This is most easily done by drilling holes and inserting the rear pin 13 of the spacer bolt 8 into the holes. A thermal insulation material 4 is then placed on the rear wall 7 and this is also covered with wear plates 5. The wear plates 5 are placed on the front pin 12 of the spacer bolts 8. The wear plates 5 have a recess 15 in the area of the front pin 12. Retaining disks 14 are placed on the front pin 12 in the area of the recess 15 and the retaining disks 14 are firmly connected to the spacer bolt 8. There is play on all sides between the retaining disks 14 and the wear plates 5.

available.
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The wear plates 5 are arranged with expansion joints 9. The expansion joints 9 are covered from the inside with cover plates 10, which are held by stabilizing ribs 11 attached to the wall. The expansion joints 9 can remain free on the walls if suitably solid thermal insulation material 4 is used.

The lining according to the invention is easy to manufacture and inexpensive to produce even in the smallest workshop. This provides good thermal insulation of the outer walls, which means that no warping or scaling of the housing walls occurs. The service life of a mill door lined according to the invention is extraordinarily long.

List of reference symbols used

1 inlet slope

2 side wall

3 Spacer bush

4 Thermal insulation material

5 Wear plate

6 threaded bolts

7 Rear wall

8 spacer bolts

9 Expansion joint

10 Cover plate

11 Stabilizing rib

. _ 12 pins &ogr;

13 cones

14 Retaining disc

15 Countersink

Claims (4)

Protection claims 1. Lining for the mill door of a fan mill, consisting of an inlet slope, two side walls and an arched rear wall, characterized,
that spacer bushings (3) are attached to the inlet slope {1) and the side walls (2) and the walls are drilled through in the area of the spacer bushings (3), thermal insulation material (4) is placed on the inlet slope (1) and the side walls (2) and covered with wear plates {5}, the wear plates (5) are attached to the wall from the outside with threaded bolts (6) through the spacer bushings (3), into which _nc Rear wall (7) spacer bolts (8) are firmly inserted, on the b A thermal insulation material (4) is placed on the rear wall and covered with wear plates (5) and the wear plates (5) are attached to the spacer bolts (8). 2. Lining according to claim 1, characterized in that the wear plates (5) are placed on a front pin (12) of the spacer bolts (8) and are held by retaining disks (14) in a recess (15) of the wear plates (5), wherein between the retaining disks (14) and the ² ^ wear plates (5) there is play on all sides. 3. Lining according to claim 1 and 2, characterized in that the wear plates (5) are arranged with expansion joints (9) relative to one another. 4. Lining according to claims 1 to 3, characterized in that the expansion joints (9) are covered from the inside with cover plates (10) which are supported by bars attached to the wall. o _C stabilization ribs (11) . 3 pages of drawings