Crushing device

Abstract

The invention relates to a breaking device for a liquid with solids, comprising a housing having an inlet opening, a discharge opening and a housing interior extending from the inlet opening to the discharge opening, a first breaking shaft extending through the housing interior, which is arranged for rotation about a first breaking shaft axis, a second breaking shaft extending through the housing interior, which is arranged for rotation about a second breaking shaft axis. The invention is characterized in that a first screening device is arranged in the housing interior adjacent to the first breaking shaft, which has a first screen wall with a plurality of slits and has a first cleaning device with a plurality of cleaning elements which are movable relative to the screen wall along a movement path, which extend through the plurality of slits over at least one section of the movement path from a first cleaning shaft arranged on one side of the first screen wall.

Description

TECHNICAL FIELD

[0001] The invention relates to a shredding device for liquids with solids, comprising a housing having an inlet opening, a discharge opening and a housing interior space extending from the inlet opening to the discharge opening, a first shredding shaft extending through the housing interior space, the first shredding shaft being arranged for rotational movement about a first shredding shaft axis and having a plurality of first shredding cutting elements fixed on the first shredding shaft axially spaced apart along the first shredding shaft axis, a drive device for driving the first shredding shaft in rotational movement, a shredding flow path extending through the interior space from the inlet opening around the first shredding shaft to the discharge opening, a first screening device arranged adjacent to the first shredding shaft in the housing interior space, the first screening device having a first screen wall with a plurality of screen wall openings and having a first cleaning device for removing blockages from the screen wall openings, the screening device and the cleaning device being movable relative to each other. BACKGROUND

[0002] The above-mentioned construction type of a shredding device is used for treating liquids carrying solids, so that the solids are shredded and, after leaving the discharge opening of the shredding device, the solids contained in the liquid no longer exceed a maximum size. Here, the solids are generally shredded by shear forces and tearing forces acting on the solids when they pass between the shredding cutting elements.

[0003] The shredding efficiency of such a shredding device depends to a large extent on the fact that the gaps and free spaces used for the passage of the liquid are minimized in such a way that solids exceeding a certain size cannot reach from the inlet opening to the discharge opening without a shredding action being exerted on such solids. This requirement leads to the fact that, in the pursuit of a high fineness and small size of the solids leaving the discharge opening, the remaining cross section for the passage of the liquid flow through the shredding device is small and, therefore, the shredding device exhibits a high flow resistance. However, the shredding device is used in many application cases precisely for installation in the inlet of a pump, in order to thereby reliably prevent the pump from being damaged by solids exceeding a certain size. Not only in self-priming pumps but also in non-self-priming pumps, the increased flow resistance in the inlet is disadvantageous for the pumping effect, so that it is pursued to implement the flow in the inlet to the pump as unresistant as possible.

[0004] It is known in principle to solve the problem of flow resistance of such a shredding device by increasing the distance between the two shredding shafts, increasing the length of the shredding shafts and increasing the size of the shredding cutting elements or increasing the diameter of the shredding cutting elements embodied as wheels having cutting teeth arranged with large dimensions. While these measures can solve the problem of high flow resistance, they can lead to the fact that the shredding device occupies a large amount of construction space, is heavy and causes additional costs in manufacturing.

[0005] A shredding device is known from WO 2018 / 146247 A1, in which, alongside the two intermeshing shredding shafts, on both sides there are curved walls provided with slits. In this device, an additional through cross section is provided for the liquid flowing through the shredding device alongside the shredding shafts, wherein only solids having a size smaller than the size of the slits can pass through this additional through cross section. In order to avoid clogging of the slits, it is provided in this device that the slits are cleaned by means of cleaning fingers which move comb-like through the slits. Although it has been shown that this type of shredding device provides an increased liquid throughput and can be kept free of clogging even over a long period of time for a plurality of types of solids. However, in certain cases, in particular when the fluid contains solids with a high proportion of solid fibers, accumulations occur in the slits which can no longer be removed even by the cleaning fingers and thus form blockages which impede the flow-through and the movement of the cleaning fingers.

[0006] A shredding device is known from WO 2019 / 126456 A1, which also has a bypass liquid guide through both rollers in a symmetrical configuration. The rollers are sealed against the housing here by means of side rails equipped with sealing elements. The sealing elements can be embodied as plastic strips or brushes. This previously known embodiment thus comprises the function that, by means of the precise sealing by means of the plastic strips or sealing brushes, the liquid can only pass through the two rollers and through the free space between the shredding elements, thus using this way that a cleaning function of the openings of the screening rollers is achieved by correspondingly generating a high pressure drop or avoiding a pressure drop through the gap space between the rollers and the inner wall of the housing. However, it has been shown in practice that the openings of the screening rollers cannot be kept sufficiently clean thereby and, depending on the properties of the solids in the solids-containing liquid input, the openings in the screening rollers can be relatively quickly clogged and, despite the establishment of the corresponding sealing and the corresponding pressure difference, cannot be washed out by themselves. SUMMARY

[0007] It is an object of the present application to provide a shredding device which, while avoiding these disadvantages, achieves a reliable shredding with reduced flow resistance not only in liquid flows with a low proportion of solids and a high volume throughput, but also in liquid flows with a high proportion of solids.

[0008] According to the application, the object is achieved by a shredding device of the type mentioned at the outset, in which a bypass flow path extending parallel to the shredding flow path extends from an inlet opening through the plurality of screen wall openings to a discharge opening, and a cleaning device is formed by at least one brush element having a plurality of bristles, wherein the first screen wall and the brush element are movable relative to one another, and the bristles at least partially engage into the screen wall openings upon relative movement of the brush element and the screen wall.

[0009] According to the invention, a brush element is provided to clear solids from or to keep clear the screen wall openings in the screen wall. For this purpose, a relative movement is provided between the brush element and the screen wall, by which the cleaning action is achieved. This relative movement can preferably be designed such that the brush element is fixedly secured on the housing and the screen wall is moved relative to the housing. However, conversely, the movement of the brush element can be prescribed when the screen wall is secured relative to the housing, or both the screen wall and the brush element can be moved relative to the housing. The invention is based on the insight that the use of a brush element instead of a cleaning finger which combs over the slots in the screen wall makes the openings in the screen wall more reliably kept clear of fibrous material. Surprisingly, by the brush element it is possible to clear such fibrous material from the openings early on before these fibrous materials have adhered to the edge of the openings, and even though the brush element is less stable than a cleaning finger and thus a cleaning device which is to be considered as working with a lower cleaning force, it still achieves a more effective keeping clear of the screen wall openings of such fibrous material. Here, the brush element can be configured by brush strips which extend along the outer wall of the screening drum. The brush element can here extend parallel to the axis of the screening drum or can extend obliquely, for example helically, around the axis of the screening drum. Preferably, the brush element is arranged with a single radius around the axis of the screening drum along its entire course, so that each section of the brush element has the same distance from the axis of the screening drum. The brush element has a plurality of bristles. These bristles are arranged next to one another in the longitudinal extension of the brush element, but can also be arranged in a plurality of rows relative to one another, so that a plurality of bristles are also arranged next to one another transversely to the longitudinal extension of the brush element. The bristles are preferably made of plastic, for example the bristles can be made of polyethylene, polyamide or polypropylene. It is particularly preferred that the bristles are harder than brushes made of natural hair, for example. In particular, brush elements whose bristles have an elastic resilience after deformation which achieves almost complete or complete elastic recovery without a plastic deformation component in the starting geometry when deformed up to 5%, preferably up to 10%, in particular up to 20%, are suitable for use according to the invention.

[0010] The bristles of the brush element are preferably at least partially embedded in the screen wall openings. This means that the screen wall and the brush element are arranged relative to one another such that the ends of the bristles at least slightly protrude into the screen wall openings when the screen wall and the brush element are not moved relative to one another. Thus, the bristles are not arranged at a distance relative to the screen wall, but rather lie against the screen wall. This achieves an effective removal of solids which are trapped in the screen wall openings. In certain application cases, the bristles can also be arranged with a small distance relative to the outer surface of the screen wall, so that only when a solid is attached in the opening and thus protrudes beyond the outer surface of the screen wall, it is acquired and removed by the bristles. This leads to a gentle design of the contact between the brush element and the screen wall and makes the wear of the bristles less.

[0011] By providing bristles according to the application, direct mechanical cleaning and clearing of the openings in the screening drum is thus achieved. To this end, the brush element can in particular be designed with mechanically robust bristles configured thereon. The brush element can be designed with the bristles in the brush element being arranged spaced apart in the axial direction of the axis of rotation of the screening drum, in particular with the bristles of the brush element being spaced apart in such a way that liquid can flow through the spaces. The brush element can in particular have a plurality of bristle tufts spaced apart axially in the direction of the axis of rotation of the screening drum, wherein a free space through which liquid can flow is respectively arranged between adjacent bristle tufts. By virtue of the flow around the bristle tufts, a good cleaning function of the brush element is thus achieved. The brush element has no sealing function here. It can in particular be provided that the brush element is not used as a sealing element, i.e. in particular is not used to seal the intermediate space between the screening drum and the housing.

[0012] The first preferred embodiment of the crushing device according to the application is characterized by a second crushing shaft extending through the interior space of the housing, the second crushing shaft being arranged for rotational movement about a second crushing shaft axis and a plurality of second crushing cutting elements being fixed to the second crushing shaft axially spaced apart along the second crushing shaft axis, a drive device being configured for driving the second crushing shaft into rotational movement. By means of such a second crushing shaft, solids in the region between the two crushing shafts and in the region outside the meshing region of the two crushing shafts respectively can be effectively crushed, this crushing action being achieved by a combined shearing action and tearing action, so that a high throughput of solids and liquid has already been achieved in the region of the two crushing shafts. Furthermore, by virtue of the flow action produced by the two crushing shafts, good flow of fluid can be achieved in the region of the crushing shafts and the region of the entry opening in front of the screen wall, which promotes the transport of large solids from the region of the screen wall into the region of the crushing shafts. To this end, it is particularly preferred that the two crushing shafts move in opposite directions to one another and in this region in which the two crushing shafts mesh with one another, rotational movement is produced, which produces a transport action from the entry opening to the discharge opening.

[0013] It is more preferred that the screening device is configured as a screening drum about a screening drum axis, the screen wall being arranged on the circumference of the screening drum. By configuring the screening device as a screening drum, it is possible to achieve advantageous flow guidance on the one hand not only on the entry opening side but also on the discharge opening side. Furthermore, by this configuration, the relative movement between the brush element and the screen wall is carried out in an advantageous manner by rotational movement or pivotal movement about the screening drum axis. The screening drum can in this case preferably be rotated or pivoted about the screening drum axis.

[0014] The crushing device can be further configured by a cleaning drive coupled to the first screening device or the first cleaning device in order to generate a relative movement between the first screening device and the first cleaning device. Such a cleaning drive, which can be configured as an electric motor or a hydraulic motor, for example, generates a preferably constant or periodically acting relative movement between the screen wall and the brush elements and thereby cleans the openings from solids. The cleaning drive can in particular also be formed by the drive of the crushing shaft, for example in such a way that the crushing shaft and the screening drum and / or the brush elements are coupled to one another and are driven synchronously by the drive. Such a coupling can be implemented by means of a gear transmission, a belt drive, a mechanical lever arrangement or the like, for example.

[0015] It is further particularly preferred that the screening drum is rotatably supported about a screening drum axis and that the cleaning drive is coupled to the screening drum for driving the screening drum in rotational movement about the screening drum axis. In this configuration, the screening drum is rotated in constant or pivotal (reciprocating) movement about the screening drum axis and the brush elements can in particular be arranged stationary on the housing and exert a cleaning action by the rotational movement of the screening drum.

[0016] According to a further preferred embodiment, it is provided that:

[0017] the screening drum is arranged adjacent to the first crushing shaft and the screen wall extends over an inlet circumferential angle from a region adjoining the crushing shaft, the inlet circumferential angle defining a circumferential section of the screening drum over which a fluid flowing in through the inlet opening can flow through the screen wall into the screening drum, and the screen wall is divided into a plurality of screen wall sections, at least one of the plurality of screen wall sections extending over a section circumferential angle about the screening drum axis which is less than or equal to the inlet circumferential angle, or

[0018] the screening drum is arranged adjacent to the first crushing shaft and the screen wall extends over an outlet circumferential angle from a region adjoining the crushing shaft, the outlet circumferential angle defining a circumferential section of the screening drum over which a fluid flowing to the discharge opening can flow out of the screening drum through the screen wall, and the screen wall is divided into a plurality of screen wall sections, at least one of the plurality of screen wall sections extending over a section circumferential angle about the screening drum axis which is less than or equal to the outlet circumferential angle.

[0019] According to this embodiment, the screen wall is divided into a plurality of screen wall sections which are arranged next to one another in the circumferential direction of the screening drum about the screening drum axis. One screen wall section thus extends about the screening drum axis only over a limited angular range which is smaller than the total circumferential angle of the screen wall, for example the screen wall can be divided into two screen wall sections each extending over 180° or into three screen wall sections each extending over a circumferential angle of 120°. At least one screen wall section of the screening drum extends over a circumferential angle which is so small that this screen wall section can be removed from the installation starting with the entry opening and removed in the direction of the entry opening or starting with the discharge opening and removed through the discharge opening. In this way, the screening drum itself can be removed without the crushing shafts having to be removed for this purpose. On the one hand, by removing the screen wall sections in this way the interior space of the screening drum is made accessible and thus the solids which have accumulated therein can be removed with little maintenance effort. In particular, it is thereby possible to remove again the smaller solids which have passed through the openings but have accumulated in the interior space of the screening drum without large maintenance effort and thereby to restore the throughput of the crushing device to the original extent. On the other hand, it is thereby also possible to access the interior space of the screening drum in a simple manner, which is helpful, for example, for maintenance work on the screening drum bearings. Finally, this configuration also allows the replacement of damaged screen wall sections in a simple manner without the screening drum having to be removed, which is again an advantageous maintenance option. For this purpose, it is particularly preferred that all screen wall sections extend over a circumferential angle which allows such removal through the entry opening or through the discharge opening without the screening drum or the crushing shaft or the crushing shafts having to be removed for this purpose.

[0020] According to a further preferred embodiment, the screening drum has a screening drum frame, the screening wall sections are fixed on the screening drum frame, and the at least one screening wall section is detachably fixed on the screening drum frame and can be radially unfolded or detached with respect to the screening drum axis. The configuration of the screening drum with the screening drum frame firstly enables the screening drum itself to have a rigid and stable support structure which has a good support of the screening wall sections even for high pressure drops which can occur from the inlet opening to the discharge opening and act on the screening wall sections. The screening drum frame can be formed by an end plate, for example a circular end plate, on each end side and struts which extend axially in the region of the outer circumference between these end plates. The struts can be arranged at an angular distance from one another which corresponds to the extension angle of the screening wall sections. It is for example preferred that the screening wall sections are fixed on the struts by means of a connection by means of a plurality of bolts, in order to achieve a stable fixing of the screening wall sections and at the same time a simple detachability. The screening wall sections can here be fixed on the screening drum frame in general detachably or unfoldably, in such a way that the screening wall sections are fixed on the screening drum frame with hinges, joints or the like. The detachability or unfoldability is here preferably designed in such a way that the screening wall sections can be taken off or unfolded radially outwards. By this configuration, the detachment or unfolding of the screening wall sections is not blocked by the material which is located in the interior space of the screening drum, so that a cleaning purpose can be achieved even in the case of a heavily soiled interior space. It is more preferred that:

[0021] - the screening wall sections are fixed on the screening drum frame in such a way that they are aligned on the outer circumference, so that the outer surface of the screening wall sections is arranged with a radius around the screening drum axis which is greater than or equal to the radius of the outwardly protruding portion of the screening drum frame, or

[0022] - the screening wall sections are fixed on the screening drum frame in such a way that they are aligned on the outer circumference with one another, so that the outer surface of the screening wall sections completely covers the screening drum frame.

[0023] According to this embodiment, the screening wall sections are arranged on the outer circumference either in such a way that the entire outer circumference of the screening drum axis is formed by the screening wall sections or the outwardly protruding portion of the screening drum frame is arranged in such a way that it is flush with the outer surface of the screening wall sections or they are arranged radially inwardly recessed with respect to one another. By this configuration it is possible to clean the openings in the screening wall sections in a simple manner by rotating the screening drum, for example in such a way that fixed brush elements are arranged at a distance from the outer surface of the screening wall sections, so that the brush elements sweep over the screening wall sections, so that the brush elements have a small distance with respect to the screening wall sections or the brush elements are applied against the outer surface of the screening wall sections, so that the bristles slightly enter into the openings.

[0024] It is further preferred that the screening drum is rotatably supported about the screening drum axis in the housing by means of two journal bearings and that the journal bearings can be detached from the interior space of the screening drum or from outside the housing. It is furthermore preferred that, after such detachment of the journal bearings or after detachment of the drum shaft bearing in general, the screening drum can be removed from the housing in radial direction about the rotary drum axis through the entry opening or the discharge opening. The configuration of the screening drum supported by means of such two journal bearings advantageously makes the screening drum detachable without requiring a significant construction space in axial direction of the screening drum axis above or below the housing for this purpose. The journal bearings here are short shafts which do not extend over the entire length of the screening drum but are provided only on the respective end-side end of the screening drum and serve for supporting the screening drum. The journal bearings or rotary bearings here can preferably be detached inwardly into the interior space of the screening drum and detached by assembly steps from inside. Thus, no access to the housing from the outside is required for detachment, so that the bearings of the screening drum can be easily detached after removal of the screen wall sections. Alternatively, in certain arrangements, it can also be preferred to detach the bearings of the screening drum from the outside, where, by using journal bearings, it is also not necessary to reserve a large assembly space, for example dimensioned according to the screening drum length, in order to be able to pull out a shaft which extends completely through the screening drum. After detachment of the bearings, the screening drum can be removed in radial direction. This allows the screening drum to be removed from the housing through the entry opening or the discharge opening and significantly simplifies the maintenance work on the screening drum or its bearings. In contrast to the general configuration in which the housing must allow removal of a cover in order to remove the screening drum in axial direction, it is possible to save significant construction space required for such removal on the one hand and, on the other hand, to achieve simple assembly and maintenance of the screening drum by using the entry opening or the discharge opening which is easily accessible in general anyway for detaching the screening drum and removing it from the housing.

[0025] It is further preferred that the screening drum is rotatably supported about the screening drum axis in the housing by means of two journal bearings and that the journal bearings can be detached from the interior space of the screening drum or from outside the housing. It is furthermore preferred that, after such detachment of the journal bearings or after detachment of the drum shaft bearing in general, the screening drum can be removed from the housing in radial direction about the rotary drum axis through the entry opening or the discharge opening. The configuration of the screening drum supported by means of such two journal bearings advantageously makes the screening drum detachable without requiring a significant construction space in axial direction of the screening drum axis above or below the housing for this purpose. The journal bearings here are short shafts which do not extend over the entire length of the screening drum but are provided only on the respective end-side end of the screening drum and serve for supporting the screening drum. The journal bearings or rotary bearings here can preferably be detached inwardly into the interior space of the screening drum and detached by assembly steps from inside. Thus, no access to the housing from the outside is required for detachment, so that the bearings of the screening drum can be easily detached after removal of the screen wall sections. Alternatively, in certain arrangements, it can also be preferred to detach the bearings of the screening drum from the outside, where, by using journal bearings, it is also not necessary to reserve a large assembly space, for example dimensioned according to the screening drum length, in order to be able to pull out a shaft which extends completely through the screening drum. After detachment of the bearings, the screening drum can be removed in radial direction. This allows the screening drum to be removed from the housing through the entry opening or the discharge opening and significantly simplifies the maintenance work on the screening drum or its bearings. In contrast to the general configuration in which the housing must allow removal of a cover in order to remove the screening drum in axial direction, it is possible to save significant construction space required for such removal on the one hand and, on the other hand, to achieve simple assembly and maintenance of the screening drum by using the entry opening or the discharge opening which is easily accessible in general anyway for detaching the screening drum and removing it from the housing.

[0026] According to the application, a screening device having a screening wall is provided. A liquid carrying solids can flow through the screening wall from an inlet opening to a discharge opening, wherein solids exceeding a determined size, i.e. exceeding the width of the screen or the size of the openings, are prevented from passing the screening wall due to a screening effect. Thus, the passage through the screening wall reduces the flow resistance through the crushing device by providing an additional flow path for the liquid. Here, solids exceeding the determined size are prevented from flowing through the crushing device on these flow paths.

[0027] In order to keep the screening wall with the openings contained therein passable, according to the application a cleaning device is also provided. The cleaning device comprises a plurality of bristles, wherein a relative movement between the bristles and the screening wall takes place. Due to this relative movement, the bristles pick up solids which partially or completely clog the openings, clean the solids and thereby keep the openings free.

[0028] In principle, the relative movement can be actively or passively driven, for example by the flow of the liquid through the crushing device, wherein this is effected by corresponding flow guiding elements coupled to the brush elements or the screening device, if necessary. Furthermore, the cleaning device or the screening device can be coupled to the first crushing shaft and / or the second crushing shaft and driven by the coupling device, which synchronizes the relative movement with the movement of the crushing cutting elements.

[0029] According to a first preferred embodiment, the crushing device can comprise a cleaning drive coupled to the first cleaning shaft and rotating the first cleaning shaft. According to a further refinement, a cleaning drive, for example an electric motor, a hydraulic motor, etc., is provided with which a cleaning shaft on which the cleaning elements are fixed is rotated, so that the cleaning elements describe a circular path as a movement path and the circular path extends at least sectionally through the gap. It is understood that each cleaning element in principle follows its own movement path, for example each cleaning element is assigned to and cleans one gap in the screening wall, or a plurality of such cleaning elements are provided for cleaning one slot and the plurality of such cleaning elements successively clear the movement path with or without deviation.

[0030] According to a further preferred embodiment, the cleaning drive comprises a fluid- dynamically acting fluid guide element which is arranged in the interior space and is flowed through by the liquid flow through the interior space, or an electrically, pneumatically or hydraulically driven motor. According to this embodiment, the cleaning drive is configured from a fluid guide element, such as a guide vane, which has been set in motion by the liquid flow through the interior space and thereby causes a rotation of the first cleaning shaft. Alternatively, a motor can be provided which generates a movement of the cleaning element which acts independently of the throughflow of the interior space. The motor can in particular be arranged outside the interior space in order thereby to avoid a loading of the motor with liquid.

[0031] According to a further preferred embodiment, the first and second crushing shafts are arranged between a first and a second screening device, the second screening device having a second screen wall with a plurality of openings and having a second cleaning device with at least one second brush element with a plurality of brush hairs, the second screen wall and the second brush element being movable relative to one another, and the brush hairs preferably at least partially engaging into the screen wall openings upon relative movement of the brush element and the second screen wall. According to this embodiment, a total of two screening devices are provided, which are preferably structurally identical and mirror-symmetrical with respect to a plane which extends centrally between the two crushing shafts in the throughflow direction and parallel to the crushing shafts through the interior space. Alternatively, however, the second screening device can also be embodied with a different geometry, a different arrangement or a different cleaning device than the first screening device. In this embodiment with two screening devices, the first and second crushing shafts are arranged between the two screening devices, so that the liquid flowing through the interior space can in total take three generally applicable liquid flow paths through the interior space, one liquid path through the first screening device, one liquid path through the second screening device, and one liquid path through the region of the two crushing shafts. The advantage of these two arrangements is that a generally uniform flow pattern is achieved at the outlet, and solids can continue to be transported through the first and second cleaning devices from both sides towards the direction of the crushing shafts as the slots in the first and second screening devices are cleaned. It is particularly advantageous for this purpose that the relative movement between the brush element and the screening device generates a fluidic out-to-in flow movement, i.e. a flow movement directed towards the crushing shafts, in order to transport the solids to the crushing shafts.

[0032] It is furthermore preferably provided that the relative movement between the first screen wall and the first brush element and the relative movement between the second screen wall and the second brush element take place synchronously, preferably by means of a mechanical coupling to a common cleaning drive. According to the present embodiment, the first cleaning drive and the second cleaning drive can be embodied integrally or coupled to one another and are jointly, in particular, placed in rotation, thereby causing a synchronous movement and synchronous drive of the first cleaning drive and the second cleaning drive.

[0033] According to a further preferred embodiment, the axial distance between two axially adjacent first crushing elements is at least the size of the ball passage of the opening in the screen wall, at least twice, at least five times, or at least ten times the size of the ball passage of the opening in the screen wall. According to this embodiment, the axial distance between two axially adjacent first crushing elements is at least twice, in particular at least five times, preferably at least ten times the size of the ball passage of the opening. According to this embodiment, the axial distance between two adjacent crushing elements in axial direction and the ball passage of the opening in the first or second screen wall have a defined minimum size ratio. The ball passage is here to be understood as a measure describing the diameter of a circular ball that just passes through the opening of the screen wall, i.e. the maximum diameter of a ball that can pass through the opening of the screen wall. By such a defined ratio it is ensured on the one hand that solids above a certain size cannot pass through the screen wall nor through the crushing shaft from the inside of the entry opening through the interior space to the exit opening. It is to be understood that the distance between two crushing elements is to be understood as the axial dimension of the free space between one crushing element and the other crushing element with respect to the rotational axis of the crushing shaft, i.e. for example in a disc-shaped crushing element having teeth on the circumference the axial distance between the mutually facing end faces of two axially adjacent disc-shaped cutting elements of the crushing shaft. It is to be understood that during operation the cutting elements of the second crushing shaft are engaged into the intermediate gap (formed by the axial distance) constituted in this way by the two crushing elements of the first crushing shaft, thereby narrowing the cross section. This makes it possible for only solids having a very small size to pass in the region where the cutting elements of the first and second crushing shafts are engaged with one another. In contrast thereto, a larger cross section is provided for the passage of solids in the region located outside thereof in which the cutting elements are not engaged with one another. In principle, the cutting elements can be embodied with a movement opposite to the flow direction of the solids in the region located outside, i.e. for example in such a way that the first and second crushing shafts are embodied with a rotation opposite to one another, said rotation pointing in the flow direction of the liquid from the entry opening to the exit opening in the region of the inner circumferential region in which the cutting elements are engaged with one another.

[0034] It is understood in principle that the free space between the cutting elements in the region located outside in which the first and second cutting elements do not engage one another can also be partially or completely filled by fixed element parts on the housing of the cutting device, the cutting elements then being correspondingly inlaid with said fixed parts in order to prevent solids of a certain size or all solids in this region located outside from passing through.

[0035] It is further preferred that the first and second crushing shafts are driven in opposite directions of rotation to one another and that the first and second crushing shaft axes preferably extend parallel to one another and spaced apart. According to this embodiment, the two crushing shafts extend parallel to one another such that the axes of rotation of the two crushing shafts have the same distance from one another everywhere. In particular, this configuration can result in a good and uniform crushing performance along the entire length of the crushing shafts.

[0036] It is further preferred that the first screen wall has a curved screen wall surface, preferably that the first screen wall is a cylindrical surface about the first screening drum axis. The configuration of the first screen wall with a curved screen wall surface facilitates the sliding of the solids along the screen wall on the one hand, thereby preventing the accumulation of solids, as would occur for example in a planar screen wall surface. In particular, the curvature of the screen wall surface can be designed such that the entry opening of the screen wall pointing towards the entry opening is convexly curved, thereby preventing the deposition and accumulation of solids on the screen wall by the possibility of the sliding of the solids along the convexly curved surface. In particular, the configuration with the convex screen wall surface allows the relative movement to occur on a circular path and thus the relative movement is realized as a rotational movement of the screen wall by the cylindrical geometry of the screen wall. BRIEF DESCRIPTION OF DRAWINGS

[0037] Preferred embodiments of the present application are explained below with reference to the drawings. The following drawings show preferred embodiments of the crushing device according to the present application in different views and perspectives. In the drawings:

[0038] Figure 1 a perspective view from an oblique side showing the crushing device according to the present application;

[0039] Figure 1 a a perspective view showing Figure 1 a detail circled and marked as "A";

[0040] Figure 1 b a perspective view showing Figure 1 a a detail circled and marked as "B";

[0041] Figure 1 c a perspective view showing Figure 1 a a detail circled and marked as "C";

[0042] Figure 2 Showing according to Figure 1 A perspective side view of the crushing apparatus according to the invention, wherein the screening drum is removed;

[0043] Figure 3 Showing according to Figure 1 A front view of the internal space of the housing of the crushing device according to the invention, wherein the screening drum is removed;

[0044] Figure 3 a shows Figure 3 A perspective view of the detail circled in the center and marked "A";

[0045] Figure 3 b shows Figure 3 A perspective view of the details circled in the center and marked "B". Detailed Implementation

[0046] Figure 1 , Figure 2 and Figure 3 The diagram shows a housing 10 of a crushing device according to the invention, having an internal space 10. The crushing device includes a first crushing shaft 11 and a second crushing shaft 12 (in...). Figure 1 (The first and second crushing shafts are rotatably supported within the housing 10 in the internal space 10a of the housing 10, about the axes 100 and 200 of the first or second crushing shafts.) The first crushing shaft 11 and the second crushing shaft 12 have multiple crushing and cutting elements constructed on cutter discs 111 and 112 and axially spaced apart along the axes of the first or second crushing shafts. Both the first and second crushing shafts 11 and 12 are composed of multiple cutter discs 111 and 112. The internal space of the housing includes an inlet opening 13 and an outlet opening 14, through which solids or liquids carrying solids can enter or exit the internal space. The crushing shafts 11 and 12 extend vertically within the internal space of the housing in their installed positions.

[0047] The two crushing shafts 11 and 12 rotate at different speeds, so that during each rotation, the other crushing elements of the adjacent cutter discs 111 and 112 of the two crushing shafts 11 and 12 interlock with each other, and a shearing action is generated between the crushing and cutting elements.

[0048] In the gear chamber a transmission 20 is provided, which consists of two gears with different numbers of teeth, which are fastened directly in torsion to the crushing shafts 11, 12 and engage with one another. Thereby opposite rotational movements of the two crushing shafts 11, 12 are generated, which run at different rotational speeds. One of the two crushing shafts 11 or 12 is led out of the housing interior and can be set in rotation by means of a drive motor 25. This rotation is transmitted by the transmission 20 to the other crushing shaft 11, 12. Thereby the first crushing shaft 11 rotates about a first crushing shaft axis and the second crushing shaft 12 rotates in the opposite rotational direction about a second crushing shaft axis. The first crushing shaft axis and the second crushing shaft axis extend parallel to one another and spaced apart.

[0049] On the periphery of each cutter head 111, 112 eight crushing cutting elements are respectively configured which are uniformly distributed in the circumferential direction. The crushing cutting elements form a helix with steep inclination along the periphery of each crushing shaft 11, 12. The crushing cutting elements of one crushing shaft form a left-hand thread and the crushing cutting elements of the other crushing shaft form a right-hand thread.

[0050] Adjacent to the first crushing shaft 11 a first screening drum 30 is provided, which is rotatably supported in the housing about a first screening drum axis 300. The first screening drum 30 comprises a first screen wall 31, which has a cylindrical surface and is formed by a total of three screen wall sections 31a-c. Each screen wall section has a plurality of openings 32.

[0051] The screening drum 30 is set in rotation about the screening drum axis 300 by means of a drive motor 35 via a transmission 36.

[0052] In Figure 1 a and Figure 1 c a brush element 50 is shown in more detail, which is adjacent to the first screening drum 30 and extends parallel to the first screening drum axis 300. The brush element 50 is arranged and fixed on an outer edge of the housing. The brush element comprises a plurality of bristles and is arranged at such a distance with respect to the first screening drum axis 300 that the bristles sweep over the outer surface of the screen wall 31 and to a small extent protrude into the openings 32. If the screening drum is rotated about the screening drum axis, the bristles thus clear the openings of solids located in the openings and keep the openings free.

[0053] Similarly, the second screening drum 40 is supported adjacent to the second crushing shaft 12 in a rotatable manner about a second screening drum axis 400, and second brush elements are arranged adjacent to the second screening drum. The mounting position of the second brush elements is indicated in the figures by the reference 60. The second screening drum 40 and the second brush elements at the assembly position 60 are configured mirror-symmetrically to the first screening drum 30 and the first brush elements 50 with respect to a mirror plane located between the two crushing shafts and comprise a cylindrical second screening wall 41 which is also formed from three screening wall segments 41a-c, each having a plurality of openings 42.

[0054] The crushing shaft axes 100, 200 and the screening drum axes 300, 400 are arranged parallel to one another and extend transversely to the throughflow direction of the housing from the inlet opening to the discharge opening.

[0055] The cylindrical faces of the first and second screening walls 31, 41 form a convex outer surface, respectively. The cylindrical face of the first screening drum points over an angular range of approximately 120° about the drum longitudinal axis towards the inlet opening and is bounded by the first crushing shaft 11 adjacent to the screening drum and the first brush elements 50. In the same way, the cylindrical face of the second screening drum points over an angular range of approximately 120° about the screening drum axis 400 towards the inlet opening and is bounded by the second crushing shaft 12 adjacent to the screening drum and the second brush elements 12.

[0056] As Figure 1 b As shown in detail, the screening wall segments 30a-c and 40a-c are detachably fixed to the first or second screening drum frame 38 by means of a plurality of bolts 37. The screening drum frame is formed by an end plate in the region of the end side and three longitudinal struts which extend axially in the region of the outer circumference. Each screening wall segment 30a-c, 40a-c extends over a circumferential angle of 120° about the drum longitudinal axis 300 or 400. After loosening the threaded fixing, the screening wall segments can thus be removed from the screening drum frame towards the inlet opening and removed through the inlet opening from the screening drum mounted in the housing, as Figure 2 is shown.

[0057] By removing the individual screening wall segments 30a, c, 40a-c, the interior space of the screening drum 30, 40 becomes accessible. As Figure 3 a and Figure 3As shown in detail in b, the screen drum 30 is mounted in the housing in a manner rotatable about the screen drum axis 300 by means of the upper journal 38 and the lower journal 39 in the upper rolling bearing 18 and in the lower sliding bearing 19. The journals are detachably fixed on the respective upper and lower end plates of the screen drum frame by means of bolts 38a, 39a. After loosening the threaded connections, the journals 38, 39 can be pulled axially out of the sliding bearings 38a, 39a into the interior space of the screen drum, thereby releasing the rotational guidance and retention of the screen drum in the housing. Thus, the screen drum can be taken out of the housing in the radial direction through the access opening, as Figure 3 shown in b.

[0058] This dismounting option is implemented in the same manner for the second screen drum 40, respectively.

Claims

1. A breaking device for a liquid with solids, the breaking device comprising: - a housing (10) having an inlet opening (13), an outlet opening (14) and a housing interior extending from the inlet opening to the outlet opening; - a first breaking shaft (11) extending through the housing interior, the first breaking shaft being arranged for rotational movement about a first breaking shaft axis (100) and having a plurality of first breaking cutting elements fixed on the first breaking shaft axially spaced apart along the first breaking shaft axis; - a drive device (20, 25) for driving the first breaking shaft in rotational movement; - a breaking flow path extending through the housing interior from the inlet opening about the first breaking shaft to the outlet opening; - a first screening device (30) arranged in the housing interior adjacent to the first breaking shaft, the first screening device having a first screen wall (31) with a plurality of screen wall openings (32) and having a first cleaning device for removing blockages from the screen wall openings, the first screening device and the first cleaning device being movable relative to each other, characterized in that - a bypass flow path extending parallel to the breaking flow path extends from the inlet opening through the screen wall openings (32) to the outlet opening, and - the first cleaning device is formed by at least one first brush element (50) having a plurality of brush hairs, wherein the first screen wall and the first brush element are movable relative to each other and the brush hairs at least partially engage into the screen wall openings upon relative movement of the first brush element and the first screen wall, - the first screening device is configured as a screening drum about a screening drum axis (300), the first screen wall being arranged on a circumference of the screening drum, wherein: - the screening drum is arranged adjacent to the first breaking shaft and the first screen wall extends over an inlet circumferential angle from an area adjoining the first breaking shaft, the inlet circumferential angle defining a circumferential section of the screening drum over which fluid flowing in through the inlet opening can flow into the screening drum through the first screen wall, and the first screen wall is divided into a plurality of screen wall sections (31a-c), at least one of the plurality of screen wall sections extending over a section circumferential angle about the screening drum axis which is less than or equal to the inlet circumferential angle, or - the screening drum is arranged adjacent to the first breaking shaft and the first screen wall extends over an outlet circumferential angle from an area adjoining the first breaking shaft, the outlet circumferential angle defining a circumferential section of the screening drum over which fluid flowing towards the outlet opening can flow out of the screening drum through the first screen wall, and the first screen wall is divided into a plurality of screen wall sections (31a-c), at least one of the plurality of screen wall sections extending over a section circumferential angle about the screening drum axis which is less than or equal to the outlet circumferential angle. The screening drum has a screening drum frame, the individual screening wall sections are fixed on the screening drum frame, and the at least one screening wall section is detachably fixed on the screening drum frame and can be radially unfolded or detached with respect to the screening drum axis, wherein the at least one screening wall section can be removed through the entry opening or through the discharge opening.

2. The crushing device of claim 1, wherein A second crushing shaft (12) is provided which extends through the interior space of the housing, is arranged for rotation about a second crushing shaft axis (200), and has a plurality of second crushing cutting elements fixed on the second crushing shaft axially spaced apart along the second crushing shaft axis, the drive device being configured to drive the second crushing shaft in rotational movement.

3. A crushing device according to claim 1 or 2, characterized in that A cleaning drive device (35, 36) is provided which is coupled with the first screening device or the first cleaning device for generating a relative movement between the first screening device and the first cleaning device.

4. The crushing device of claim 3, wherein The screening drum is rotatably supported about a screening drum axis, and the cleaning drive device is coupled with the screening drum for driving the screening drum in rotational movement about the screening drum axis.

5. The crushing device according to claim 1 or 2, characterized in that - the individual screening wall sections are fixed on the screening drum frame in alignment on the outer periphery, such that the outer surface of the screening wall sections is arranged about the screening drum axis with a radius which is greater than or equal to the radius of the outwardly protruding portion of the screening drum frame, or - the individual screening wall sections are fixed on the screening drum frame in alignment with one another on the outer periphery, such that the outer surface of the screening wall sections completely covers the screening drum frame.

6. A crushing device according to claim 1 or 2, characterized in that The screening drum is rotatably supported in the housing about the screening drum axis by means of two journal bearings (38, 39), and the journal bearings are detachable from the interior space of the screening drum or from outside the housing.

7. The crushing device of claim 6, wherein After detachment of the journal bearings, the screening drum can be removed from the housing in the radial direction about the screening drum axis through the entry opening or the discharge opening.

8. A crushing device according to claim 1 or 2, characterized in that The screening drum is rotatably supported in the housing about the screening drum axis on a first end with a first rotational bearing and on a second end with a second rotational bearing, and the first rotational bearing and / or the second rotational bearing is a plain bearing (19).

9. The crushing device of claim 8, wherein, The lower arranged rotational bearing in the installed position of the crushing device is a plain bearing (19).

10. The crushing device of claim 3, wherein The cleaning drive device comprises: - a fluid-dynamically acting fluid guiding element which is arranged in the interior space of the housing and is flowed through by a liquid flow of the interior space of the housing; or - an electrically, pneumatically or hydraulically driven motor.

11. The crushing device of claim 1, wherein A second screening device is provided in the interior space of the housing, the first crushing shaft is arranged between the first screening device and the second screening device, the second screening device has a second screening wall with a plurality of screening wall openings and has a second cleaning device with at least one second brush element with a plurality of brush hairs, the second screening wall and the second brush element are movable relative to one another, and the brush hairs at least partially engage into the screening wall openings of the second screening wall when the second brush element and the second screening wall move relative to one another.

12. The crushing device of claim 2, wherein, A second screening device is provided in the internal space of the housing. A first crushing shaft and a second crushing shaft are disposed between the first screening device and the second screening device. The second screening device has a second screen wall with multiple screen wall openings and a second cleaning device. The second cleaning device has at least one second brush element with multiple bristles. The second screen wall and the second brush element can move relative to each other, and the bristles are at least partially embedded in the screen wall openings of the second screen wall when the second brush element moves relative to the second screen wall.

13. A crushing device according to claim 11 or 12, characterized in that The relative movement between the first screen wall and the first brush element and the relative movement between the second screen wall and the second brush element occur synchronously.

14. The crushing device of claim 13, wherein The relative motion between the first screen wall and the first brush element and the relative motion between the second screen wall and the second brush element are synchronized by means of mechanical coupling to a common cleaning drive.

15. The crushing device according to claim 1 or 2, characterized in that The axial distance between two axially adjacent first crushing and cutting elements is at least the same as the size of the ball channel of the screen wall opening in the first screen wall.

16. A crushing device according to claim 1 or 2, characterized in that The axial distance between two axially adjacent first crushing and cutting elements is at least twice the size of the ball channel of the screen wall opening in the first screen wall.

17. A crushing device according to claim 1 or 2, characterized in that The axial distance between two axially adjacent first crushing and cutting elements is at least five times the size of the ball channel of the screen wall opening in the first screen wall.

18. A crushing device according to claim 1 or 2, characterized in that The axial distance between two axially adjacent first crushing and cutting elements is at least ten times the size of the ball channel of the screen wall opening in the first screen wall.

19. A crushing device according to claim 1 or 2, characterized in that Each or at least one of the screen wall openings extends circumferentially in the first screen wall by a length such that the length differs from the axial extension dimension of the screen wall opening about the axis of the screening drum by no more than 50%.

20. The crushing device of claim 2, wherein, The first and second crushing shafts are driven in opposite directions of rotation.

21. The crushing device of claim 20, wherein, The first crushing shaft axis and the second crushing shaft axis extend parallel to each other and spaced apart.

22. The crushing device of claim 20, wherein, The first screen wall has a curved screen wall surface.

23. The crushing device of claim 22, wherein, The screen wall surface is a cylindrical surface surrounding the axis of the screening drum of the first screening device.

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