AT525727B1 - press screw separator - Google Patents

Abstract

The invention relates to a press screw separator (1) for separating solid components from a sludge containing solid and liquid components, comprising: a housing (2), a cylindrical screen (4) which is arranged in the housing (2), and a screen ( 4) arranged and rotatably mounted about a longitudinal axis (6) of the sieve (4) clearing element (3) for pressing out the slurry, wherein the housing (2) comprises a first housing part (20) and a second housing part (21), the second Housing part (21) adjoins the first housing part (20) in the direction of the longitudinal axis (6), with a first screen area (41) of the screen (4) being mounted in the first housing part (20) in a rotationally fixed manner, and with a second screen area (42) of the screen (4) is mounted without play in the radial direction of the screen in the second housing part (21) and makes direct contact with the second housing part (21).

Description

Description

PRESSING SCREW SEPARATOR

The present invention relates to a press screw separator for separating solid components from a slurry containing solid and liquid components.

[0002]Press screw separators are used to press out a slurry. The pulp can be liquid manure or waste water in particular. The waste water can come from agricultural, municipal and industrial plants, whereby it should always be separated into solid and liquid components. In some cases it is advantageous to add precipitants or flocculants to the pulp before pressing it out. A cylindrical screen is usually arranged in the housing of the press screw separator, within which a clearing element rotates. The pulp is conveyed and pressed through the press screw separator by means of the clearing element. The liquid parts of the sludge pass through the sieve, while a solid plug forms inside the sieve. The solid plug is conveyed to one end of the press screw separator by the rotating clearing element, in order to be ejected there. The torque is transmitted from the clearing element to the screen via the solid plug. The screen must therefore be arranged in the housing in a rotationally fixed manner.

In practice it has been shown that when solids are pressed out to a high dry content, a high bursting pressure acts on the screen. EP 2 938 418 B1 describes a press screw separator with a frame which is fastened in the housing of the press screw separator and in which a part of the screening area is mounted. This frame supports the screen, preventing screen failure. With this solution, it is disadvantageous in terms of manufacturing costs and maintenance that an additional component is required in the housing with the frame.

DE 202011105765 U1 shows a screen arrangement for a press screw separator, comprising a rigid, hollow-cylindrical shell and a hollow-cylindrical screen resting against the inner surface of the shell. Holding rods are attached to the outside of the jacket. The screen arrangement is mounted and fixed in the press screw separator with these holding rods. DE 102011080865 A1 shows further relevant prior art.

For the present invention, therefore, based on the prior art described above, the task of creating a technically simple press screw separator of the type mentioned, which enables safe, reliable and low-maintenance operation with simple and inexpensive production.

[0006] The object is achieved by a press screw separator for separating solid components from a slurry containing solid and liquid components

a housing, a cylindrical screen, which is arranged in the housing, and a clearing element, which is arranged inside the screen and is mounted so that it can rotate about a longitudinal axis of the screen, for pressing out the pulp, the housing comprising a first housing part and a second housing part, with a first screen area of the Screen is rotatably mounted in the first housing part, and wherein a second screen area of the screen is mounted without play in the second housing part and directly contacts the second housing part.

According to the invention, the object is achieved by a press screw separator which includes a housing in which a screen is mounted. As with other press screw separators, this housing absorbs all radial and axial forces acting during operation. The press screw separator according to the invention usually comprises a cover surrounding the housing in order to concentrate and drain off the liquid phase after separation. This cover can be removed quickly and easily for maintenance work. Furthermore, the press screw separator according to the invention comprises a clearing element, which is arranged within the screen and is mounted such that it can rotate about a longitudinal axis of the screen, for pressing out the slurry. The screen is therefore usually of cylindrical design, with the housing also preferably being of cylindrical design. As a supporting component, this housing accommodates all in operation

occurring radial and axial forces. Part of the screen is accommodated in this housing without play. The housing according to the invention therefore enables not only the task of absorbing all other radial and axial forces but also a supporting function of a screen area against the bursting pressure prevailing in this screen area, so that the screen can absorb significantly higher forces than would be the case without the supporting function of the housing.

According to the invention, a first screen area of the screen is rotatably mounted in the housing, while a second screen area of the screen is mounted without play in the housing. Thus, the arrangement according to the invention allows the reinforcing second area of the housing to be provided only at those points of the screen where particularly high forces occur and which are therefore potential failure points. The first screen area, which is not supported by the housing, can also be mounted in the housing in a rotationally fixed manner in a very simple manner. The housing can thus support the screen in the second screen area, so that no deformation and thus no failure of the screen is possible here. The second screen area is in particular that area of the screen where the greatest dry matter content occurs within the press screw separator. This means that in the second screen area the pulp is largely separated into its solid and liquid components and the plug forms. In other words, the second screening area is behind the first screening area in the conveying direction of the clearing element.

The solution according to the invention differs from EP 2 938 418 B1 in that a two-part housing is provided so that no separate frame has to be inserted into the housing. In the solution according to the invention, the second screen area is therefore not connected to a separate frame, but directly to the second housing part, which means that a frame that would have to be inserted into the housing can be dispensed with. This is made possible by the second housing part, which adjoins the first housing part in the longitudinal direction of the screen. Compared to the devices of DE 202011105765 U1 and DE 102011080865 A1, the advantage is achieved that part of the sieve can be mounted in a rotationally fixed manner and part can be mounted without play.

The screen preferably has a plurality of bars oriented parallel to the longitudinal axis. Such bar screens have advantageous properties when used in press screw separators, since in particular there are no elements running in the circumferential direction that could be damaged by the solid plug conveyed by the clearing element.

Furthermore, it is preferably provided that the supporting second region of the housing comprises support rings which are normal to the axis of rotation. This has the advantage that only the supporting bars of the screen are covered by the supporting housing. The area between the supporting bars of the screen, which is important for separating the liquid components of the pulp, remains free. This enables a high performance of the press screw separator. As an alternative to the support rings, a rolled-up elongated perforated plate or a rolled-up perforated plate could also be used, with the support rings being advantageous over such solutions since they do not cover any parts of the open screen surface.

Furthermore, it is preferably provided that the supporting area of the housing has at least one reinforcement strip which extends parallel to the longitudinal axis. It is provided in particular that boreholes, threaded holes and/or threaded rods are provided in the reinforcement strip, by means of which a retaining strip can be screwed to the housing. In particular, the reinforcing strip makes it possible to design the frame to be very stiff, as a result of which deformation of the screen together with the housing can be prevented.

Advantageously, the second screen area has a recess in the direction of the longitudinal axis. A lug of the housing can preferably engage in this recess in order to prevent rotation of the second screen area about the longitudinal axis relative to the housing. Since, as described above, the rotation of the clearing element is transmitted to the screen, torsion within the screen can be prevented in this way. It is thus possible to keep unnecessary stresses away from the wire. Furthermore, the nose can be designed

Store sieve within the housing. Alternatively or additionally, the lug can be designed to clamp the screen within the housing. This can be done in particular in that the screen has a cylindrical base body, with a slot being present parallel to the longitudinal axis over the entire lateral surface. Therefore, a lug of larger dimension than the slot engaging the slot can increase the outer diameter of the screen, thus forcing the screen into the frame.

In a preferred embodiment, the housing has a retaining strip which can be connected to the rest of the housing. Particularly preferably, the holding strip can be screwed to the housing. The nose of the housing can preferably be formed in this way. This has the advantage that the nose of the housing can be removed, which makes it easier, for example, to install and/or remove the screen.

Furthermore, it is preferably provided that the second screen area takes up a proportion of up to 30%, in particular up to 50%, of the screen. As previously described, the highest forces within the press screw separator occur within the second screening area. Therefore, according to the invention, the second screen area is to be selected according to the values mentioned in order to ensure that failure of the screen due to the occurrence of excessive forces is ruled out.

It is also preferred if the press screw separator comprises an inlet housing on which the housing is mounted on one side for absorbing torques of the clearing element. The housing is thus only supported on one side and protrudes freely on the side facing away from the inlet housing.

In particular in the aforementioned embodiment it can be preferred if the first housing part comprises at least two rods which support both the first screening area and the second housing part. The bars can thus preferably extend between the inlet housing and the second housing part, with the first screening area being able to be supported on these bars at the same time. Particularly preferably, only two bars are used and the first housing part has no further elements in the circumferential direction in the area of the bars, in order to enable deformation of the first screen area.

[0018]More preferably, the press screw separator can comprise a cover which is arranged around the housing or under the housing in order to collect the pulp that has passed through the housing. Thus, the housing can be made to absorb the torque without having to take over the function of collecting the separated liquid, which can take place through the cover, which in turn does not have to absorb the torque of the reaming element. It is particularly advantageous here that more space is available for additional components between the housing and the cover.

In particular, a washing device can be arranged in this gained space between the housing and the cover, which preferably comprises a washing ring driven by a linear drive, which is arranged around the housing. Using spray nozzles on the washing ring, a large part of the screen can be washed without having to remove the screen from the press screw separator.

The invention will now be described in detail using an exemplary embodiment, taking into account the accompanying drawings. In the drawings is:

1 shows a schematic representation of a press screw separator according to an embodiment of the invention, and

Figure 2 is a schematic representation of the second screen section of the screen together with the second housing section of the press screw separator according to the preferred embodiment of the invention.

FIG. 3 shows a sectional view of the second housing part and the second screen area.

FIG. 4 shows a schematic representation of the press screw separator according to the invention in a particularly preferred embodiment.

shows a press screw separator 1, which has a housing 2, the housing 2 is further divided into a first housing area 20 and a second housing area 21. Both the first housing area 20 and the second housing area 21 are usually substantially cylindrical executed and can each have a longitudinal axis. To form the housing 2 , the two housing areas 20 , 21 are lined up along the longitudinal axes in order to form a substantially cylindrical housing 2 . In order to connect the two housing parts 20, 21 to one another, a flange connection is preferably used, as shown in FIG. 1, although another type of connection such as a welded connection or a slip connection can also be used.

In the following, only those components of the press screw separator 1 that are important for the present invention are described. All other components correspond to those components as are used in known press screw separators.

Within the housing 2, a clearing element 3 is arranged, which in particular comprises two circumferential coils. A slurry can be compressed by the clearing element 3, so that liquid components can be separated from solid components. The clearing element thus has a conveying direction towards which the slurry is conveyed in order to compress it. A sieve 4 is provided for this purpose, which extends cylindrically around the clearing element 3 . The screen 4 has a longitudinal axis 6 which is also the longitudinal axis of the clearing element 3 at the same time. The longitudinal axis 6 of the screen usually coincides with the longitudinal axis of the housing sections 20,21. Furthermore, the screen 4 is divided into a first screen area 41 and a second screen area 42 . The first screen area 41 can have a design that differs from the design of the second screen area 42 . In addition, it is preferably provided that the first screen area 41 and the second screen area 42 are installed separately from one another.

In the example shown in FIG. 1, the first screen area 41 is connected to the first housing area 20 via holding brackets that are not visible in FIG the clearing element 3 rotates. However, it can be provided in particular that the first screen area 41 is only mounted in a rotationally fixed manner and not without play in the radial direction of the screen 4, i.e. an elliptical deformation of the first screen area 41 is made possible in particular. In other words, the first screen area 41 can be mounted with a degree of freedom in the radial direction. In the present invention, for example, the first housing portion 20 may be constituted by two or more rods extending in the axial direction. The rods can on the one hand each linearly support the first screen area 41 (so that the first screen area 41 can, for example, deform elliptically between the rods) and on the other hand support the second housing area 21 . The first housing area 20 could, for example, comprise a flange ring at that end of the rods which faces the second housing area 21 in order to facilitate the connection of the second housing area 21 .

The second screen area 42 is mounted without play directly in the second housing area 21 in the radial direction of the screen 4 . As a result, the second housing area 21 largely prevents deformation of the second screen area 42. The second screen area 42 and the second housing area 21 are arranged directly in front of an outlet 22 of the housing 2, since the highest forces act on the screen 4 here. This results from the fact that the slurry is compressed along the longitudinal axis 6, i.e. in the conveying direction of the clearing element 3, with liquid components continuously passing through the screen 4 and the solid components of the slurry remaining within the screen 4. Thus, as the solids approach the outlet 22, the dry matter content of the solids within the screen 4 steadily increases. The second housing area 21 prevents the second screen area 42 from being destroyed by the occurrence of excessive forces. The second screen area 42 makes up about 30-50% of the total length

of the screen 4, which is sufficient for a support function with the second housing area. Overall, safer and more reliable operation is thus made possible, since the sieve 4 is protected against failure.

An exploded drawing can be seen from FIG. 2, which shows the second screen area 42, the second housing area 21, and a holding strip 7, which forms a nose of the second housing area, in a preferred embodiment. It can be seen that the second screen area 42 has a recess 43 which extends over the entire lateral surface of the second screen area 42 parallel to the longitudinal axis 6 and is preferably reinforced by end strips. The retaining strip 7 can engage in this recess 43 and can in particular be screwed to the second housing area 21 . For this purpose, the second housing area 21 has a reinforcement strip 24 in which bores are provided, so that the holding strip 7 can be screwed inside the reinforcement strip 24 . It is also possible for the retaining strip to be connected to the reinforcement strip 24 via other fastening means. In particular, this can be a rivet connection or an adhesive connection. The second housing area 21 can have further reinforcement strips 24, in which case not every reinforcement strip 24 has to be provided with a retaining strip 7. In particular, it is provided that only one holding strip 7 is arranged on the second housing area 21 .

The screen 4 is designed in particular as a bar screen. The screen 4 therefore has a large number of bars 44 which are oriented along the longitudinal axis 6 . A gap width of the sieve is defined by a distance between the rods 44, so that the quality of the solid to be pressed out can be determined. The longitudinal rods 44 are connected via a plurality of ring-shaped support rods 45 which extend around the longitudinal axis 6 .

Finally, it can be seen from FIG. 2 that the second housing area 21 is made up of rings 23, among other things. These rings 23 form the contact surface for the second screen area 42, which is thus mounted in the second housing area 21 without play in the radial direction of the screen 4. The support rods 45 of the second screen area 42 rest against the rings 23 of the second screen area 42 without play. The second housing area 21 thus absorbs the bursting pressure prevailing in the second screen area 42 . A failure of the second screen area 42 and thus of the screen 4 is therefore almost impossible. Furthermore, the area between the individual support rods 45 remains free and allows the separated liquid part of the sludge to drain freely.

Figure 3 shows a sectional view of the second housing part 21 and the second screen area 42, which is formed with support rods 45 in the illustrated embodiment. It can be seen at the first point S1 that the support rods 45 rest directly on the respective retaining ring 23 so that the second screen area 42 is mounted in the second housing part 21 without play in the radial direction of the screen 4 . In principle, it would also be possible to mount the second screen area 42 in a different way in the radial direction of the screen 4 without play in the second housing part 21, e.g. if the second housing part 21 comprises a rolled-up elongated perforated plate or a rolled-up perforated plate in which the sieve rests. The second sieve area 42 is usually also mounted in the second housing part 21 in a rotationally fixed manner, since the holding strip 7 engages in a recess in the second sieve area 42 . However, a small gap can also occur at the second point S2 between the retaining strip 7 and the second screen area 42 due to the torque during operation, since the second screen area 42 is usually not mounted in a completely rotationally fixed manner.

Figure 4 shows a particularly preferred embodiment of the press screw separator 1 according to the invention with a drive 81 of the clearing element 3 and an inlet housing 82 for feeding the pulp to the clearing element. What is special about this embodiment is that, in contrast to other separators, there is no closed housing that absorbs the entire torque and also drains off the separated liquid. Instead, the two-part housing 2 is provided, which absorbs the torque and allows the liquid to pass freely. There is also a cover 83 which catches the liquid which has passed through the housing 2 . The two-part housing 2, or more precisely the first housing part 20, is mounted on one side on the inlet housing 82. The other end of the case, i.e. the

second housing part 21 is usually freely available and is not stored separately. The cover 83 is arranged loosely around the housing 2 and does not absorb any torque from the clearing element 3 or the slurry.

Such an embodiment with housing 2 and cover 83 makes it possible, for example, to provide a washing device between housing 2 and cover 83, which can clean a large part of the screen. The washing device can, for example, comprise a washing ring 84 which is arranged between the cover 83 and the housing 2 and can be moved in the axial direction by means of a linear drive 85 . The sieve 4 can be cleaned by means of spray nozzles which are provided around the circumference of the washing ring and are directed in the direction of the housing 2 .

REFERENCE LIST:

1 press screw separator 2 housing

20 First part of the housing 21 Second part of the housing 22 Outlet of the housing 23 Retaining ring

24 Reinforcement strip 3 clearing element

4 screens

41 First screen area 42 Second screen area 43 Recess

44 longitudinal bar

45 support bar

6 longitudinal axis

7 retaining bar

81 drive

82 inlet housing

83 cover

84 wash ring

85 linear drive

Claims (14)

patent claims 1. Press screw separator (1) for separating solid components from a pulp containing solid and liquid components, comprising: - a housing (2), - a cylindrical screen (4) which is arranged in the housing (2), and - an inside the screen (4) arranged and rotatably mounted about a longitudinal axis (6) of the sieve (4) clearing element (3) for pressing out the pulp, characterized in that the housing (2) comprises a first housing part (20) and a second housing part (21). , the second housing part (21) adjoining the first housing part (20) in the direction of the longitudinal axis (6), a first screen area (41) of the screen (4) being non-rotatably mounted in the first housing part (20), and a second The sieve area (42) of the sieve (4) is mounted without play in the second housing part (21) in the radial direction of the sieve (4) and makes direct contact with the second housing part (21). 2. Press screw separator according to claim 1, characterized in that the second screen area comprises annular support rods (45), the second housing area (21) being designed with retaining rings (23) in which the support rods (45) of the second screen area (42) are mounted are. 3. Press screw separator according to claim 2, characterized in that each retaining ring (23) in the second housing area (21) is opposite a supporting rod (45) of the second screen area (42). 4. Press screw separator according to claim 2, characterized in that only every second, every third or every fourth supporting bar (45) of the second screen area (42) is opposite a retaining ring (23) in the second housing area (21). 5. Press screw separator according to one of the preceding claims, characterized in that the second housing part (21) has at least one reinforcing strip (24) which extends parallel to the longitudinal axis (6). 6. Press screw separator according to one of the preceding claims, characterized in that the first screen area (41) is elastically deformable. 7. Press screw separator according to one of the preceding claims, characterized in that the second screen area (42) has a recess (43) in the direction of the longitudinal axis (6), in which a lug of the second housing part (21) engages to prevent rotation of the second Screen area (42) to prevent the longitudinal axis (6). 8. Press screw separator according to Claim 7, characterized in that the second housing part (21) comprises a retaining strip (7) which can be connected, in particular screwed, to the second housing part (21) in order to close the nose of the second housing part (21). form. 9. Press screw separator according to one of the preceding claims, characterized in that the second screen area (42) takes up a proportion of up to 30%, in particular up to 50%, of the screen (4). 10. Press screw separator according to one of the preceding claims, characterized in that the second housing part (21) is connected to the first housing part (20) by means of a flange connection. 11. Press screw separator according to one of the preceding claims, characterized in that the press screw separator (1) further comprises an inlet housing (82) on which the housing (2) is mounted on one side for absorbing torques of the clearing element (3). 12. Press screw separator according to any one of the preceding claims, characterized in that the first housing part (20) comprises at least two rods which support both the first screening area (41) and the second housing part (21). 13. Press screw separator according to one of the preceding claims, characterized in that the press screw separator (1) further comprises a cover (83) which is arranged around the housing (2) or under the housing (2) in order to ) to catch the pulp that has passed through. 14. Press screw separator according to claim 13, characterized in that the press screw separator (1) further comprises a washing device arranged between the housing (2) and the cover (83), which preferably comprises a washing ring (84) driven by a linear drive (85), which is arranged around the housing (2). 2 sheets of drawings