Grinding mill

Abstract

Disclosed is a grinding mechanism with two counter-rotating, oppositely arranged grinding rollers (2), which form an adjustable grinding gap (3). Grinding material is fed to the grinding gap (3) via a grinding material inlet, and the ground material is discharged below the grinding gap (3) via an outlet (6). The grinding rollers (2) are arranged in a housing (1), the front of which can be opened by means of a door or removable cover. The grinding rollers (2) are mounted exclusively at the rear of the housing (1) and can be removed from the front when the housing (1) is open.

Description

[0001] Grinding mills with a wide variety of grinding tools are known. The invention relates to a grinding mill equipped with one or two grinding rollers. If two grinding rollers are provided, they are arranged opposite one another and rotate in opposite directions, with the material to be ground being introduced into the grinding gap formed between the grinding rollers. If only one grinding roller is provided, the grinding process usually takes place in a gap between the grinding roller and the housing in which the roller is located. Such a grinding mill is known, for example, from document DE 20 2009 013 268.

[0002] Depending on their application, grinding mills must be cleaned regularly. In addition to the desired ground material, which is discharged via an outlet, other particles, dust, and deposits build up in the grinding mill, which sooner or later impair the grinding result. Therefore, such grinding mills must be cleaned regularly, with particular attention being given to cleaning the surface of the grinding rollers.

[0003] The object of the invention is to create a grinder that can be equipped with one or two grinding rollers and that can be cleaned easily and quickly.

[0004] This object is achieved by the features of claim 1 and claim 9. Claim 1 is directed to a grinding mechanism with two counter-rotating, oppositely arranged grinding rollers which form an adjustable grinding gap to which grinding material is fed via a grinding material inlet. The ground material is discharged via an outlet. The grinding rollers are arranged in a housing which, according to the invention, can be easily opened from the front by means of a door or a removable cover. The grinding rollers are mounted exclusively at the rear of the housing and thus rotate with the front side free-standing in the housing. Therefore, since they are only mounted on one side at the rear of the housing, the grinding rollers can be easily removed to the front of the opened housing and then easily cleaned. The grinding rollers advantageously have a ring-like shape.

[0005] A further advantage is that the grinding rollers can be easily replaced with other rollers depending on the application of the grinder.

[0006] Grinding mills of this type are often equipped with an extraction system. The housing in which the grinding roller(s) are mounted has an extraction opening connected to a vacuum generator. By generating a vacuum, unwanted particles, especially dust, can be extracted, thus reducing contamination of the grinding mill. Nevertheless, intensive cleaning of the grinding mill is necessary at certain intervals, particularly due to adhesions to the grinding rollers. According to the invention as defined in claim 9, the grinding mill is equipped with a housing for accommodating the at least one grinding roller, which housing is easily opened by means of a door or a removable cover. The aforementioned extraction opening is not connected directly to a vacuum generator, but rather via a three-way valve.To clean the grinder, the three-way valve can be adjusted so that the vacuum is not applied to the suction opening of the housing, but to another inlet of the three-way valve, which can be connected to a hose with which the user can vacuum the interior of the housing and in particular the grinding roller(s) after opening the housing in order to remove any buildup.

[0007] A further advantage is that the vacuum level, or rather the airflow from the housing to the vacuum generator, can be adjusted using the three-way valve. This allows the additional inlet, which is not connected to the housing, to be either completely closed or gradually opened until, in extreme cases, the air is completely drawn in through the additional inlet and not through the housing. This eliminates the need to control the vacuum generator, as the desired airflow can be easily adjusted using the three-way valve.

[0008] Further advantageous developments arise from the subclaims.

[0009] If the grinding roller(s) are mounted exclusively on the rear side of the housing, they are preferably connected to the drive shaft(s) in a rotationally fixed manner from the freestanding front side. For this purpose, fastening devices, such as screws, can be provided that are easily removable from the front side.

[0010] In a design with two counter-rotating, oppositely arranged grinding rollers, the roller gap can be adjusted by moving at least one grinding roller on a carriage. Advantageously, the grinding roller can be moved together with its drive.

[0011] In a design with two grinding rollers, the speed of these rollers can be adjusted to different speeds. Depending on the grinding task, the counter-rotating grinding rollers can be operated at the same speed or at different speeds.

[0012] Of course, the easy cleaning of the grinder by means of a vacuum generator connected to the housing via a rotary valve can, as discussed, also be applied to a grinder with two counter-rotating grinding rollers.

[0013] It has proven effective to provide a cyclone between the vacuum generator and the aforementioned three-way valve to separate particles. Furthermore, an air filter can advantageously be provided, particularly preferably directly upstream of the vacuum generator, to filter out even the finest dust and thus ensure a dust-free environment. This allows for a long service life of the vacuum generator.

[0014] The invention is described in more detail using a preferred embodiment. Fig. 1 shows the grinder with two counter-rotating, oppositely arranged grinding rollers with the housing open. Fig. 2 shows the grinder with the housing connected.

[0015] In Fig. 1 The grinder is shown with the housing 1 open. To ensure optimal accessibility, the entire front of the housing 1 can be removed. This can be provided with a viewing window. The two free-standing grinding rollers 2 are clearly visible, their drive shafts mounted on the hidden rear of the housing. Two spaced-apart bearings are provided for this purpose. Each drive roller is driven separately by a motor. Between the grinding rollers 2 is the grinding gap 3, in which the material to be ground is ground.

[0016] The ground material is introduced via a funnel 4 and a ground material inlet 5 with a ground material doser on the housing and falls into the grinding gap 3. The ground material is drawn off via an outlet 6 in the lower part of the housing 1, which is also funnel-shaped in the lower area, and falls into a collecting container 7.

[0017] To adjust the grinding gap 3, the grinding roller 2 (on the left in the illustration) is mounted slidably together with the drive unit on a carriage (not visible) on the rear of the housing 1. Naturally, all openings in the housing 1 are provided with appropriate seals to prevent the escape of dust and the like. The roller gap 3 is adjusted via a handwheel 8 by moving the grinding roller 2 with the associated drive unit. Electrical adjustment is also possible.

[0018] Fasteners 10 can be seen on the freestanding front side 9 of the grinding rollers 2. In the specific embodiment, these are six screws each, by means of which the grinding rollers 2 are connected to the corresponding drive shafts. Any other fastening methods are possible. To remove the grinding rollers 2, whether for cleaning or to replace them with different grinding rollers, simply loosen these screws, and the grinding rollers, since they are only mounted at the rear, can be pulled forward. This allows for simple and comparatively quick cleaning of the rollers.

[0019] Fig. 2 shows the grinder with the housing closed. This illustration explains the functionality of the vacuum generator and the extraction system.

[0020] The vacuum generator 11 can be seen on the right-hand side of the illustration. This is a vacuum pump that operates at a constant speed. No control is required. An extraction opening 12 is provided on the closed housing 1 and can be arranged in the removable front part of the housing 1 or the remaining part of the housing 1. From this opening, a line 13 leads to an inlet 15 of the three-way valve 14. The three-way valve 14 also has a second inlet 16, shown open here. A line also leads from the three-way valve 14 to a cyclone 17, by means of which particles are separated in a collecting container 18. From the cyclone 17, in turn, a line leads to an air filter 19, which is connected to the vacuum generator 11. The function of the extraction system and the three-way valve 14 is explained below.As explained, the vacuum generator 11 runs at a constant speed if a vacuum is to be generated. If the vacuum is to be applied completely to the housing 1 in order to extract a maximum air flow from the housing 1, the three-way valve 14 is set so that the second inlet 16 is blocked, so that the vacuum generator 11 is connected exclusively to the housing 1 via the air filter 19 and the cyclone 17. If a lower air flow is desired, the three-way valve 14 is set so that the second inlet opening 16 is more or less open and thus air is also sucked in via the second inlet opening 16, whereby the air flow out of the housing 1 is correspondingly reduced. Advantageously, the three-way valve 14 allows continuous, stepless adjustment and can completely open or close both the first inlet 15 and the second inlet 16, or assume any intermediate position.

[0021] In the Fig. 2 The second inlet 16 is shown open. However, this can be permanently fitted with a hose through which secondary air can be drawn in as required, or this hose is only attached when the grinder needs to be cleaned. For this purpose, the front of the housing is opened, as shown in Fig. 1 As shown, the three-way valve 14 is set so that the vacuum generator 11 draws air exclusively through the second inlet 16. The hose can then be used to vacuum both the housing and the grinding rollers, allowing them to be easily cleaned of any buildup. A separate cleaning device is not required.

Claims

1. Grinding mechanism with two counter-rotating, oppositely arranged grinding rollers (2), which form an adjustable grinding gap (3), a grinding material inlet (5) via which grinding material is fed to the grinding gap (3), and the ground material is discharged below the grinding gap (3) via an outlet (6), wherein the grinding rollers (2) are arranged in a housing (1), the front of which can be opened by means of a door or removable cover, wherein the grinding rollers (2) are mounted exclusively at the rear of the housing (1) and can be removed from the front when the housing (1) is open.

2. Grinder according to claim 1, characterized in that the grinding rollers (2) can be exchanged for differently designed grinding rollers (2).

3. Grinder according to claim 1 or 2, characterized in that the grinding rollers (2) are connected to the drive shafts in a rotationally fixed manner by means of fastening means (10) accessible from their free-standing front side.

4. Grinder according to one of claims 1 to 3, characterized in thatthe roller gap (3) is adjustable by displacement of at least one grinding roller (2) on a carriage, wherein the grinding roller (2) is advantageously displaceable together with the drive.

5. Grinder according to one of claims 1 to 4, characterized in that the speed of the two grinding rollers (2) can be adjusted to different values.

6. Grinder according to one of claims 1 to 5, characterized in that the housing (1) has a suction opening (12) which can be connected to a vacuum generator (11).

7. Grinder according to claim 6, characterized in that the vacuum generator (11) is connected to the suction opening (12) and a second inlet (16) via a three-way valve (14).

8. Grinder according to claim 7, characterized in that the three-way valve (14) is adjustable so that the vacuum between the suction opening (12) and the second inlet (16) can be dosed.

9. Grinder with at least one grinding roller (2) arranged in a housing (1) which has a grinding material inlet (5) through which grinding material is fed, and an outlet (6) through which the ground material is discharged, wherein the housing (1) can be opened by means of a door or removable cover, and has a suction opening (12) which is connected to a vacuum generator (11) by means of a three-way valve (14) which is also connected to a second inlet.

10. Grinder according to claim 9, characterized in that the three-way valve (14) is adjustable so that the vacuum between the suction opening (12) and the second inlet (16) can be dosed.

11. Grinder according to claim 10, characterized in that the vacuum can be applied completely to the suction opening (12) or the second inlet (16), and any intermediate positions can be realized.

12. Grinder according to one of claims 9 to 11, characterized in thata cyclone (17) for separating solids is provided between the vacuum generator and the three-way valve (14).

13. Grinder according to one of claims 9 to 12, characterized in that an air filter (19) is provided between the vacuum generator (11) and the three-way valve (13), preferably directly in front of the vacuum generator (11).

14. Grinder according to one of claims 9 to 13, characterized in that the vacuum generator is not adjustable and creates a constant vacuum.

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