grinder

Abstract

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 below the grinding gap (3) is discharged 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.

Description

Grinding units 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, these are arranged opposite one another and rotate in opposite directions, wherein the grinding material is introduced into the grinding gap which is formed between the grinding rollers. If only one grinding roller is provided, the grinding operation usually takes place in a gap between the grinding roller and the housing in which the roller is provided. Such a grinding mill is known, for example, from the document DE 20 2009 013 268.Depending on the field of use, grinding units must be cleaned regularly. In addition to the desired ground material, which is discharged via an outlet, further particles, dust and adhesions are formed in the grinding mechanism, which particles or adhesions adversely affect the grinding result earlier or later. Therefore, such grinding units must be cleaned regularly, wherein in particular a cleaning of the surface of the grinding rollers is required.The object of the invention is to provide a grinding mill which can be equipped with one or two grinding rollers which can be cleaned easily and quickly.This object is achieved by the features of claim 1 and claim 9. Claim 1 is directed to a grinding mechanism having two counterrotating, oppositely arranged grinding rollers which form an adjustable grinding gap to which grinding product is fed via a grinding product inlet. The ground material is discharged via an outlet. The grinding rollers are arranged in a housing which according to the invention is easily openable from the front by means of a door or a removable cover. The grinding rollers are mounted exclusively on the rear side of the housing and thus rotate with the front side in the housing in a free-standing manner. Therefore, since the grinding rollers are supported only on one side on the rear side of the housing, they can be easily removed to the front side of the opened housing and then easily cleaned. The grinding rollers advantageously have a ring-like shape.A further advantage is that the grinding rollers can be replaced very easily by other rollers depending on the field of use of the grinding mechanism.Frequently, grinding units of the generic type are equipped with suction. The housing in which the grinding roller or rollers are mounted has a suction opening which is connected to a vacuum generator. By generating a vacuum, undesired particles, in particular dust, can be suctioned off and thus the contamination of the grinding mechanism can be reduced. Nevertheless, at certain time intervals, intensive cleaning of the grinding mechanism is necessary, in particular because of adhesions to the grinding rollers. According to the invention of claim 9, the grinding mill is provided with a housing for receiving the at least one grinding roller, which is easily openable by means of a door or a removable cover. Said suction opening is not directly connected to a vacuum generator, but via a three-way valve. For cleaning the grinding unit, the three-way valve can be adjusted in such a way that the vacuum does not lie at the suction opening of the housing, but at a further inlet of the three-way valve, which can be connected to a hose, with which the user, after opening the housing, can suck off the housing interior and in particular the grinding roller or the grinding rollers in order to remove adhesions.A further advantage is that the level of the vacuum or the air flow from the housing to the vacuum generator can be adjusted by means of the three-way valve by either completely closing or partially opening the additional inlet which is not connected to the housing, until, in the extreme case, it is sucked in completely via the additional inlet and not via the housing. In this way, control of the vacuum generator is superfluous, because the desired air flow can be easily adjusted via the three-way valve mentioned.Further advantageous developments are evident from the dependent claims.If the grinding roller(s) is or are mounted exclusively on the rear side of the housing, they are advantageously connected to the drive shaft(s) in a rotationally fixed manner from the free-standing front side. For this purpose, fastening means, for example screws, can be provided which can be easily loosened from the front side.In a construction with two counterrotating grinding rollers arranged opposite one another, the roller gap can be adjustable by displacing at least one grinding roller on a carriage. Advantageously, the grinding roller is displaceable together with its drive.In a construction with two grinding rollers, the rotational speed of these can be set differently. Depending on what is present for a grinding task, the counter-rotating grinding rollers can be operated at the same rotational speed or at different rotational speeds.It is understood that the easy cleaning of the grinding mill by means of a vacuum generator connected to the housing via a rotary directional valve, as discussed, can also be applied to a grinding mill with two counterrotating grinding rollers.It has proved to be advantageous to provide a cyclone for separating particles between the vacuum generator and the three-way valve. Furthermore, an air filter can advantageously be provided in particular preferably directly upstream of the vacuum generator in order to filter out even very fine dust and thus ensure freedom from dust. This allows a long service life of the vacuum generator.The invention will be described in more detail with reference to a preferred embodiment. FIG. 1 shows the grinding mechanism with two counterrotating, oppositely arranged grinding rollers with the housing open. FIG. 2 shows the grinding mechanism with the housing connected.FIG. 1 shows the grinding mechanism with the housing 1 open. In order to ensure optimum accessibility, the entire front side of the housing 1 can be removed. This can be provided with a viewing window. The two free-standing grinding rollers 2 can be seen well, the drive shafts of which are mounted on the rear side of the housing, which is not visible. For this purpose, two spaced-apart bearings are provided. Each drive roller is driven separately by a motor. Between the grinding rollers 2 is the grinding gap 3, in which the ground material is ground.The ground material is introduced on the housing via a hopper 4 and a ground material inlet 5 with a ground material meter and falls into the grinding gap 3.For adjusting the grinding gap 3, the grinding roller 2 on the left in the illustration is mounted displaceably together with the drive unit on a carriage, which is not visible, on the rear side of the housing 1. Of course, all the apertures on the housing 1 are provided with corresponding seals in order to prevent dust and the like from escaping. The roll gap 3 is adjusted by means of a hand wheel 8 by displacing the grinding roll 2 with the associated drive unit. In principle, an electrical adjustment is also possible.Fastening means 10 can be seen on the free-standing front side 9 of the grinding rollers 2. In the specific embodiment, these are six screws, by means of which the grinding rollers 2 are connected to the associated drive shafts. Any other fastenings are possible. In order to remove the grinding rollers 2, whether for cleaning or for replacement with other types of grinding rollers, only these screws have to be loosened and the grinding rollers can be pulled off forward, since they are mounted exclusively on the rear side. This allows simple and comparatively rapid cleaning of the rollers.FIG. 2 shows the grinding mechanism with a closed housing. The mode of operation of the vacuum generator and the suction device is explained on the basis of this illustration.On the right-hand side in the illustration, the vacuum generator 11 can be seen. This is a vacuum pump which is operated at constant speed. Regulation is not necessary. On the closed housing 1, a suction opening 12 is provided, which can be arranged in the removable front part of the housing 1 or the remaining part of the housing 1. From this, a line 13 leads to an inlet 15 of the three-way valve 14. From the three-way valve 14, a line leads to a cyclone 17, by means of which particles are separated out 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 mode of operation of the extraction device or of the three-way valve 14 is explained below. As stated, the vacuum generator 11 is to generate a vacuum at a constant speed. If the vacuum is to be applied completely to the housing 1 in order to suck a maximum air flow from the housing 1, the three-way valve 14 is adjusted such 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 adjusted such that the second inlet opening 16 is more or less open and thus air is also drawn in via the second inlet opening 16, whereby the air flow from the housing 1 is correspondingly reduced. Advantageously, the three-way valve 14 allows continuous continuous continuously variable adjustment and can fully open or close both the first inlet 15 and the second inlet 16, or assume any intermediate position.In FIG. 2, the second inlet 16 is shown open. However, this can be permanently provided with a hose, via which any secondary air is sucked in to the desired extent, or this hose is merely placed on it when the cleaning of the grinding mechanism has to be carried out. For this purpose, the front side of the housing is then opened, as shown in FIG. 1, and the three-way valve 14 is adjusted such that the vacuum generator 11 draws in air exclusively via the second inlet 16. The tube can then be used to suck off both the housing and the grinding rollers and these can easily be cleaned of adhesions in this way. A separate cleaning device is not required.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 20 2009 013 268

[0001]

Claims

Grinding mechanism having two counterrotating grinding rollers (2) arranged opposite one another, 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 side of which can be opened by means of a door or removable cover, wherein the grinding rollers (2) are mounted exclusively on the rear side of the housing (1) and can be removed from the front side when the housing (1) is open.Grinding mechanism according to claim 1, characterised in that the grinding rollers (2) can be exchanged for grinding rollers (2) of different design.Grinding mill according to claim 1 or 2, characterised in that the grinding rollers (2) are connected to the drive shafts in a rotationally fixed manner by means of fastening means (10) which are accessible from their free-standing front side.Grinding mechanism according to one of claims 1 to 3, characterised in that the roller nip (3) can be adjusted by displacement of at least one grinding roller (2) on a slide, wherein the grinding roller (2) is advantageously displaceable together with the drive.Grinding mechanism according to one of Claims 1 to 4, characterized in that the rotational speed of the two grinding rollers (2) can be set to different values.Grinding mill 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).Grinding mill according to claim 6, characterised in that the vacuum generator (11) is connected via a three-way valve (14) to the suction opening (12) and a second inlet (16).Grinding mill according to claim 7, characterised in that the three-way valve (14) is adjustable in such a way that the vacuum between the suction opening (12) and the second inlet (16) can be metered.Grinding mill comprising at least one grinding roller (2) arranged in a housing (1) having a grinding material inlet (5) via which grinding material is supplied, and an outlet (6) via which the ground material is discharged, wherein the housing (1) is openable by means of a door or removable cover, and a suction opening (12) connected to a vacuum generator (11) by means of a three-way valve (14) also connected to a second inlet.Grinding mill according to claim 9, characterised in that the three-way valve (14) is adjustable in such a way that the vacuum between the suction opening (12) and the second inlet (16) can be metered.Grinding unit according to claim 10, characterised 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.Grinding mill according to one of Claims 9 to 11, characterized in that a cyclone (17) for separating solids is provided between the vacuum generator and the three-way valve (14).Grinding mill 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 upstream of the vacuum generator (11).Grinding mill according to one of Claims 9 to 13, characterized in that the vacuum generator cannot be regulated and generates a constant vacuum.

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