Helical screw conveyor unit, worm shaft, worm extruder and method for preparing a worm shaft

Abstract

The present invention relates to a helical screw conveyor unit (100), which is formed as a replacement part for a screw-shaped or helically wound helix (240) of a worm shaft (200) of a worm extruder, and which has a base body (10) with a screw-shaped wound helix (30) to allow the helical screw conveyor unit (100) to be serviced with less maintenance effort, the upper side (16) of the mantle surface is curved concavely in a shell shape about the longitudinal axis (L) and the base body It is proposed that - the helical screw conveyor unit (100) has a radial opening (20) formed to pass a fixing area (40) of the shaft (230) of the worm axle (200), - the helical member (30) has at most half a helical turn, - the outer surface of the base body (10) has an inner surface (18) formed to rest on the fixing area (40), and - the helical screw conveyor unit (100) has at least one fixing member (34) formed to removably fix the base body (10) to the fixing area (40).

Description

[Technical Field]

[0001] The present invention relates to a helical screw conveyor unit as defined in the preamble of claim 1. The invention further relates to a worm shaft, in other words a conveyor worm, as defined in the preamble of claim 6.

[0002] The invention further relates to a worm extruder as defined in the preamble of claim 14.

[0003] The invention also relates to a method for preparing a worm shaft, which is constructed according to the preamble of claim 15. [Background technology]

[0004] Worm shafts for use in worm extruders and the general construction of worm extruders for dewatering suspensions are described, for example, in EP 1 072 574 A, US 2017 / 08778 A and EP 2 792 739 A.

[0005] EP 1 072 574 A1 discloses a fermentation plant having a fermenter and a dewatering device in the form of a cylindrical worm conveyor, which extends along a straight axis. As shown in Figures 1 to 3, a helical element with a worm shaft forms a fixed unit.

[0006] U.S. Patent Application Publication No. 2017 / 08778 discloses a worm extruder for dewatering an aqueous suspension of organic material. The device has an extruder chamber in which an extruder worm having a helical member is wound in a screw shape and supported for rotation about its longitudinal axis. To enable easy and quick maintenance of the worm extruder, U.S. Patent Application Publication No. 2017 / 08778 teaches the provision of a multi-section, highly movable screen basket, which allows easy access to the extruder chamber and allows for basket replacement by one person.

[0007] EP 2792739 A1 discloses a double worm shaft in an extruder chamber, known for example as an example of a cell disruption extruder, in which the helical screw conveyor unit has so-called tooth spacers on the side-by-side worm shafts.

[0008] Anaerobic digestion (AD) is a bioprocess that energetically utilizes organic residues, especially green waste, by converting them into biogas. The substrate is solubilized under anaerobic conditions in a fermenter, the waste-containing fermentation material is mixed with a liquid, and the resulting fermentation material suspension is subjected to anaerobically fermentation in the fermenter.

[0009] The digestate produced during the fermentation of the fermentation material suspension is dewatered using a worm extruder, whereby the press water is separated, resulting in a press cake with an increased ratio of dry substrate to digestate. After the substrate leaves the fermenter, it is thus separated into solid and liquid fermentation residues by the worm extruder.

[0010] Essentially, a worm extruder has an internal worm shaft with a helical element wound like a screw, and a screen drum or screen cylinder surrounding the worm shaft. The digested liquid to be dewatered is pumped into the screen drum via the digested liquid inlet. The worm shaft rotates, thereby transporting the digested liquid to the press cake outlet, where it is pressed against a resistance, e.g., a counter-pressure cone. Press water flows out via the press water outlet.

[0011] The further the digestate is transported forward, i.e., in the direction of resistance, the more its volume decreases and the greater the pressure on the digestate, forcing more liquid out of the digestate, which then exits as press water. The dewatered press cake leaves the worm extruder through the press cake outlet.

[0012] When driving a worm extruder, the helical element wears over time. This wear occurs more rapidly the more pressure the helical element exerts on the digestate, and is particularly pronounced in the area in front of the worm shaft, near the press cake outlet. Wear causes the pressing point to move backward, thereby weakening the dewatering of the digestate. Worn helical elements must therefore be repaired or replaced.

[0013] As shown in Figures 2 and 3 of U.S. Patent Application Publication No. 2017 / 08778, the helical members are typically rigidly connected, e.g., welded, to the shaft of the worm shaft, so that when an individual helical member wears, extensive welding must be performed or the entire worm shaft must be replaced.

[0014] EP 0 098 340 A1 discloses a worm pump for transporting solid and particulate materials. To replace the end region of the worm helix, which is subject to particularly high wear, a replaceable sleeve is provided in the end region, which can be axially removed from the worm shaft. To replace the sleeve, the worm shaft must be removed from the worm pump.

[0015] Furthermore, GB 859416 A1 discloses a worm spiral conveyor having a replacement spiral member that can be inserted as a sleeve. To enable the removal of individual sections of the worm shaft for maintenance and repair work, the worm shaft is constructed from a number of connected sleeve-shaped longitudinal sections. These longitudinal sections are removably fixed to the worm shaft shaft using semicircular bracket-shaped bearings. After loosening the bearings, the sleeve-shaped longitudinal sections can be pulled axially from the worm shaft shaft, so the worm shaft must be removable from its bearings on at least one side.

[0016] To avoid the need to repair worn-out blades of a worm conveyor by laborious welding, Chinese Utility Model No. 212831025 teaches fixing the blades to the shaft using grooves and screws. The blades are separate paddle-shaped members that are screwed onto the shaft independently of each other. [Prior art documents] [Patent documents]

[0017] [Patent Document 1] European Patent Application Publication No. 1072574 [Patent Document 2] US Patent Application Publication No. 2017 / 08778 [Patent Document 3] European Patent Application Publication No. 2792739 [Patent Document 4] European Patent Application Publication No. 0098340 [Patent Document 5] British Patent Application Publication No. 859416 [Patent Document 6] Chinese Utility Model No. 212831025 Summary of the Invention [Problem to be solved by the invention]

[0018] The object of the present invention is to further develop the spiral screw conveyor unit of the type mentioned at the beginning, the worm shaft of the type mentioned at the beginning, the worm extruder of the type mentioned at the beginning, and the method of the type mentioned at the beginning, so that the spiral screw conveyor unit can be serviced with reduced maintenance effort. In particular, a spiral screw conveyor unit configured as a replacement part for the spiral must be replaceable without removing the worm shaft from its bearing. Furthermore, the maintenance costs of the worm shaft must be reduced. [Means for solving the problem]

[0019] This problem is solved by a helical screw conveyor unit having the features of claim 1, by a worm shaft having the features of claim 6, by a worm extruder having the features of claim 14 and by a method having the features of claim 15. Preferred embodiments and expedient developments of the invention are characterized in the respective dependent claims.

[0020] The invention is therefore based on the fact that the helical screw conveyor unit can be mounted radially replaceably on the fixed region of the shaft of the worm shaft, i.e., the helical screw conveyor unit can be mounted as a replaceable replacement on the rotatably supported worm shaft of the worm extruder. The invention therefore allows for a quick replacement of the helical screw conveyor unit, since the radial opening of the base body of the helical screw conveyor unit, which is designed to accommodate the shaft, allows it to be mounted radially replaceably on the shaft, and can be replaced even if the shaft is supported at its axial end in at least one rotary bearing.

[0021] Here, "radial" refers to a direction perpendicular to the longitudinal axis (L) of the worm shaft or base body of the worm shaft. Therefore, radial replacement allows for efficient replacement of the helical member without removing the worm shaft from its bearing, allowing for extended operation of the worm shaft.

[0022] The shaft of the worm shaft is a bar-shaped member for transmitting rotational motion. The helical screw conveyor unit can be attached to the fixed area of ​​the shaft as a removable replacement part. The helical screw conveyor unit is therefore preferably configured to be removably attached to the fixed area of ​​the above-mentioned worm shaft. Furthermore, the worm shaft is preferably suitable for installation in a worm extruder of the above-mentioned type.

[0023] For releasably fixing the base body of the helical member to the fixing area, the helical screw conveyor unit has at least one fixing member, and thus preferably the fixing member of the helical screw conveyor unit of the above-mentioned kind is releasably connectable with the fixing means, in particular with the fixing structure, of the worm shaft of the above-mentioned kind.

[0024] In a preferred embodiment, the base body is a foot member of the helical member, the foot member being arranged in a radially inner region of the helical member, and the fixing member is configured to removably fix the foot member to the fixing region, the foot member being mountable on the fixing region in the form of a foot, and the helical member extending outwardly away from the foot member.

[0025] In order to radially and removably fix the helical member to the worm shaft in a simple manner, the fixing member can extend radially into a support area of ​​the shaft in its use position that is configured to support the helical screw conveyor unit, and a foot member placed on the fixing area can be fixed to the support area.

[0026] In a preferred embodiment, the support area of ​​the shaft has at least two helical members, each of which is associated with at least one fastening element, and the fastening elements of adjacent helical members are axially and radially offset relative to one another. The fastening elements are preferably cylindrical bolts and the fastening means are screws. Alternatively, the fastening elements can cooperate with the fastening means in the form of removable snap fasteners.

[0027] Preferably, the inner surface of the base body of the helical screw conveyor unit of the above-mentioned kind is configured to rest on, and in particular to bear against, a fastening area of ​​the worm shaft of the above-mentioned kind, in other words the fastening area corresponds to a region of the worm shaft that is configured to support the base body of the helical screw conveyor unit.

[0028] To facilitate particularly easy replacement of the helical screw conveyor unit on the worm shaft, the inner surface of the base body is preferably shaped so that placing the inner surface of the base body on the fastening area of ​​the worm shaft determines the orientation of the helical element of the helical screw conveyor unit on the worm shaft and at least limits the radial mobility of the base body on the worm shaft. Therefore, the inner surface of the base body and the fastening area preferably have a shape or structure that cooperates and prevents radial sliding or rotational movement of the helical screw conveyor unit about the shaft. Radial rotational movement of the helical screw conveyor unit about the shaft is then already prevented by the cooperation of the shape or structure of the fastening area with the shape or structure of the inner surface of the base body. In this case, a fastening means is used for further or additional fastening. As will be explained in more detail below, this fastening achieved by shape or structure can be achieved, for example, by the square shape of the fastening area. The fastening area is configured to removably fasten the fastening member of the helical screw conveyor unit and is associated with a support area of ​​the worm shaft shaft configured to support the helical screw conveyor unit. The fastening area has at least one fastening means, e.g., a fastening structure. Preferably, the support area has at least two fastening areas, so that preferably at least two helical screw conveyor units of the above-mentioned kind can be removably fastened to the support area of ​​the worm shaft.

[0029] Therefore, preferably, the worm shaft has at least two helical screw conveyor units. In this case, the fastening areas of the support area are preferably configured as follows: adjacent helical screw conveyor units are respectively arranged axially and radially offset with respect to one another, for example, mirror-symmetrically offset. In this preferred embodiment, the worm shaft has at least two helical members arranged axially and radially offset with respect to one another. Thus, the support area has at least two fastening areas arranged axially and radially offset with respect to one another. Preferably, in this embodiment, the fastening elements of adjacent helical screw conveyor units are also arranged axially and radially offset with respect to one another, for example, offset by 90 degrees, for example, perpendicular to one another.

[0030] The helical element has a partial helical turn, for example, a quarter to a half helical turn. A plurality of adjacent helical elements together form a helical, helix, or screw-shaped helical turn. A plurality of helical turns together form a helix wound around the screw, helix, or spiral shape of the worm shaft. In the present invention, the helical elements are replaceable, so that increased material wear of these helical elements can be tolerated compared to worm shafts known from the prior art that have non-removable helical elements, and the resistance of the worm extruder can be increased, for example, the counter-pressure cone can be enlarged or lengthened, to provide a greater power consumption for dewatering the digestive fluid.

[0031] The base body of the helical screw conveyor unit has a radial opening through which the fastening area can be guided radially, i.e., perpendicular to the longitudinal axis (L) of the base body, and can be arranged on the inner surface of the base body. In other words, the support area can be inserted into the opening and accommodated in a hollow space surrounded by the concave base body.

[0032] The fixing member is preferably configured to provide a complementary connection between the base body and the support region or axial body member of the shaft, for example a bolt, such as a cylindrical bolt, Alternatively, the fixing member may be configured to provide a snap or clip connection.

[0033] In order to enable the base body to be supported and positioned on the support area, the inner surface of the base body is configured in a shape complementary to the fixing area, and the outer surface of the base body is concavely curved and extends around the longitudinal axis, preferably in a half-shell shape or semicircular shape.

[0034] The fixing area has at least one support surface configured to support the base body, in particular the inner surface of the base body. To prevent the base body from sliding on the support surface, the inner surface of the outer surface of the base body preferably has at least one contour configured to position the base body fixedly in place on the fixing area, and preferably configured in a shape complementary to the fixing area or to the support surface of the fixing area. Preferably, the contour of the inner surface of the base body of the helical screw conveyor unit is configured in a U-shaped or N-shaped cross section.

[0035] The helical screw conveyor unit on the worm shaft can be replaced particularly quickly and simply if the helical element is formed in such a way that by placing the inner surface of the base body on the fixing area of ​​the worm shaft, the helical element is oriented and thereby at least substantially extends the course of the spiral wound on the thread or helical shape of the worm shaft.

[0036] To prevent radial sliding of the base body on the shaft, the inner surface of the mantle surface can be formed, for example, at right angles, bent, curved or stepped. For example, the fastening region can be formed in a U-shape in cross section and the inner surface of the base body in an N-shape in cross section, or vice versa.

[0037] The support area of ​​the shaft can be configured as a square, at least in the area of ​​the fastening area. Alternatively, the fastening area can be formed by at least one recess or at least one groove in the otherwise cylindrical support area. For example, the fastening area can be a U-shaped or N-shaped recess in the otherwise cylindrical support area. To prevent the helical screw conveyor unit from sliding on the fastening area, the fastening area preferably has a square seat.

[0038] The helical member has a part or section of a helical revolution, preferably half a helical revolution. Alternatively, the helical member can have, for example, one-third or one-quarter of a helical revolution. The helical screw conveyor unit has at least one helical unit, preferably a plurality, for example, four, helical units arranged side by side. To achieve a correct fit, the helical members of the helical screw conveyor units arranged side by side can be welded and ground together.

[0039] Preferably, in its use position, the fastening element extends radially through the support area and projects into the base body or through the base body of at least one helical screw conveyor unit arranged in the support area. Particularly preferably, the fastening element projects into the base body of the helical screw conveyor unit with its end projecting from the support area. Thus, in order to replace the helical screw conveyor unit, the fastening element only needs to be partially removed, e.g., removed only from the base body of the helical screw conveyor unit, while remaining fixed to the support area. This prevents the fastening element from being lost.

[0040] The worm shaft preferably has at least one helical screw conveyor member of the type described above, in which case the helical screw conveyor member is removably fixable to the fixing area.

[0041] In addition to the helical screw conveyor member, the shaft may further comprise a cylindrical shaft body extending along the longitudinal axis with at least one shaft body helix wound in a screw-like manner around the shaft body. The fixing area with the support area also extending along the longitudinal axis has a smaller cross-sectional diameter compared to the cylindrical shaft body. This allows the helical screw conveyor unit to be arranged on the support area so that the upper side of its outer surface is flush with the cylindrical shaft body.

[0042] Preferably, the support area is arranged eccentrically, in particular in a region near the end of the cylindrical shaft body, e.g., at the end. The worm shaft can be arranged in the worm extruder as follows: at least one replaceable helical element is arranged in the front region of the worm extruder, near the press cake outlet. Replacing only the most worn front helical element allows for simple, fast, and less costly maintenance of the worm shaft.

[0043] In a preferred embodiment of the method of the present invention, the worm shaft comprises: - at least one fastening means for fastening the first helical screw conveyor unit to the fastening area is loosened; - the first helical screw conveyor unit is removed from the worm shaft; -Other helical screw conveyor units are placed in the fixed area, and - by being removably fastened to the fastening area by means of fastening means associated with this other helical screw conveyor unit;

[0044] The invention also relates to the use of at least one worm shaft of the type described above in a worm extruder of the type described above for separating solid and liquid fermentation residues from biological residues, in particular green waste, which have been treated using fermenters.

[0045] As already discussed above, there are various possibilities for shaping and developing the teachings of the present invention in a preferred manner, to which, on the one hand, reference is made to the claims dependent on claims 1 and 6, and on the other hand, further aspects, features and advantages of the present invention will be explained in more detail below, in particular by means of the examples made clear by figures 1 to 7. [Brief explanation of the drawings]

[0046] [Figure 1] 1 is a perspective view of a longitudinal section of a first embodiment of a worm shaft according to the present invention, on which a helical screw conveyor unit according to the present invention is removably disposed and replaceable according to the method of the present invention. [Figure 2] FIG. 2 is a longitudinal cross-sectional view of the worm shaft of FIG. [Figure 3] FIG. 3 is a side view of the worm shaft of FIG. [Figure 4] FIG. 4 is a detailed view of the front region of the worm shaft of FIG. [Figure 5] 5 is a cross-sectional view of the helical screw conveyor unit of FIG. 1 taken along line BB shown in FIG. [Figure 6] FIG. 6 is an exploded perspective view of the worm shaft of FIG. [Figure 7] FIG. 7 shows an embodiment of a worm extruder according to the present invention having the worm shaft of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0047] In Figures 1 to 7, the same or similar features, components or features have the same reference numerals.

[0048] 1 shows an embodiment of a helical screw conveyor unit 100 for a worm shaft 200. The helical screw conveyor unit 100 has a base body 10 extending along a longitudinal axis L. The base body has two end regions that extend perpendicular to the longitudinal axis, i.e., facing each other in the direction of the longitudinal axis. The end regions 12, 14 are connected to each other by a mantle surface, around whose upper side 16, i.e., the outside, at least one helical member 30 is arranged, winding in a screw-like manner.

[0049] 1-3, the worm shaft 200 has a plurality of, for example, two, helical members 30. The helical members 30 can be welded and ground together to connect them with the correct fit.

[0050] At least one helical element 30 has a partial helical turn, in particular a quarter to half a helical turn. The base body is concavely curved, i.e., inwardly curved, and has a radial opening 20. In other words, the base body is hollow and extends in an arc about a longitudinal axis L. Preferably, the base body extends in a partially circular shape, for example in the shape of a half shell, about the longitudinal axis L.

[0051] The helical screw conveyor unit 100 is configured to be replaceably mounted on a worm shaft 200, preferably on the worm shaft 200 of a worm extruder 300 configured to dewater digestate obtained by anaerobic fermentation of organic material.

[0052] 6 shows an exploded perspective view of the worm shaft 200. This worm shaft has four helical screw conveyor units 100, which together form two rotating helices. Adjacent helical screw conveyor units 100 are radially offset by 180° relative to each other, thus being mirror-symmetrical. Base body 10Each helical screw conveyor unit has two cylindrical bolts 34 for removably fastening the helical screw conveyor unit 100 to the fastening area 40 of the support area 210. The fastening area 40 is formed in a partially square or rectangular shape. The area of ​​the support area 210 facing the helical screw conveyor unit 100 or the fastening area 40 is configured as a filling body, which supports and stabilizes the support area 210. This filling body is rigidly connected to the support area 210 and can, for example, be formed integrally with the support area 210 or can be removably fastened to the support area 210. The filling body is concavely curved about the longitudinal axis L.

[0053] As shown in Figure 7, the worm extruder 300 has an inner worm shaft 200 with helical members 30, 210 that wind in a screw shape that extends away from the outside, and a screen drum 340 that encases the worm shaft 200. The screen drum 340 can have a swingable screen shell, which allows for easy access to the worm shaft and quick replacement of screen and wear parts.

[0054] The helical screw conveyor unit 100 is provided with a worm shaft 200 for interchangeable mounting. - on the outer surface of the base body 10, it has an inner surface 18 configured to accommodate the support area 210 of the shaft 230; and It has at least one fixing member 34 configured to removably fix the inner surface 18 to the support area 210 .

[0055] The helical screw conveyor unit 100 is therefore a removably fixable or replaceable member for the worm shaft 200 .

[0056] In an embodiment of the invention not shown here, the worm shaft 200 can have only the replaceable helical member 30. Alternatively, as shown in Figures 1 to 7, only a partial area of ​​the worm shaft 200, for example the front area near the press cake outlet 350 in the use position, can be configured as a replaceable helical screw conveyor unit 100.

[0057] 1 to 7, in addition to the replaceable helical screw conveyor unit 100, further comprises a shaft 230 with a cylindrical shaft body and a shaft body helix 240 wound in a screw-like manner around the shaft 230. In the region of the cylindrical shaft body, the shaft body helix 240 is permanently connected to the shaft 230, for example being formed integrally with the shaft 230 or being welded thereto.

[0058] The support area 210 of the helical screw conveyor unit 100 can be permanently connected to the cylindrical shaft body, for example by welding techniques, for example by means of a weld seam 232. Alternatively, the support area 210 can be integrally formed with the cylindrical shaft body of the shaft 230.

[0059] The helical screw conveyor unit 100 is arranged so that the helical member 30 extends the course of the shaft body helix 240 of the cylindrical shaft body to form a common shaft body helix unit therewith.

[0060] The base body 10 of the helical screw conveyor unit 100 is concavely curved. In this case, the base body can be configured in such a way that, in the operating position of the worm shaft 200, the support area 210 is completely enclosed by the base body 10 of the helical screw conveyor unit 100 arranged on the support area 210 (not shown). For example, two helical screw conveyor units 100 configured as half shells each can completely enclose the shaft body part 210.

[0061] Alternatively, the base body 10 can be a foot member 32 of the helical member 30, which is arranged in a radially inner region of the helical member 30 and can be replaceably arranged in a fixing region 40 configured as a groove in the support region 210.

[0062] 1-7, the helical frequency of the helical member 30 is the same as the helical frequency of the shaft body helix 240. However, the helical frequency or pitch of the helical member 30 can be increased compared to the helical frequency of the shaft body helix 240.

[0063] To rotatably support the worm shaft 200 within the worm extruder 300, the worm extruder has at least one rotation bearing 250. To relieve the radial and axial force loads of the gear mechanism of the worm extruder 300, the worm shaft 200 can be double-bearing, which allows for a longer lifespan of the worm extruder 300.

[0064] The preferred material for the helical screw conveyor unit 100 of the type described above and the worm shaft 200 of the type described above is steel. The present disclosure also includes the following aspects. [Aspect 1] A helical screw conveyor unit (100) configured as a replacement part for a screw- or helically wound helix (240) of a worm shaft (200), comprising a base body (10) extending along a longitudinal axis (L), the base body (10) having two axial end regions (12, 14) and a mantle surface connecting the end regions (12, 14) to each other, on an upper side (16) of the mantle surface at least one screw-wound helical member (30) arranged, the screw-wound helical member extending radially outward from the upper side (16), the upper side (16) of the mantle surface is curved concavely in the shape of a shell about the longitudinal axis (L), and the base body (10) has radial openings (20) configured such that a fixing area (40) of a shaft (230) of the worm shaft (200) can be guided through the opening (20) in a direction perpendicular to the longitudinal axis (L) and can be placed in a hollow space formed by the base body (10), - the helical element (30) has at most half a helical turn, the outer surface of the base body (10) has an inner surface (18) configured to rest on the fixing area (40); and - the spiral screw conveyor unit (100) comprises at least one fixing member (34) configured to removably fix the base body (10) to the fixing area (40). [Aspect 2] 2. The helical screw conveyor unit according to claim 1, characterized in that the base body (10) extends in a semicircular or half-shell shape around the longitudinal axis (L), in particular is configured as a half-shell, and the helical member (30) has half a helical revolution. Aspect 3 3. The helical screw conveyor unit according to claim 1 or 2, wherein the inner surface (18) of the base body (10) is shaped in such a way that, as a result of the inner surface (18) of the base body (10) resting on the fixing area (40) of the worm shaft (200), the orientation of the helical member (30) of the helical screw conveyor unit (100) on the worm shaft (200) is determined and the radial mobility of the base body (10) on the worm shaft (200) is at least limited. Aspect 4 4. The helical screw conveyor unit according to claim 3, wherein the inner surface (18) of the mantle surface has a contour of a shape complementary to the fixing region (40) of the shaft (230) for the orientation of the helical member (30) on the worm shaft (200). Aspect 5 4. The helical screw conveyor unit according to claim 2 or 3, characterized in that the helical member (30) is shaped in such a way that, as a result of the inner surface (18) of the base body (10) resting on the fixing area (40) of the worm shaft (200), the helical member (30) is oriented at least substantially in the extension of the course of the helix (240) wound in the thread or spiral shape of the worm shaft (200). Aspect 6 A worm shaft (200) for use in a worm extruder (300), having a shaft (230) extending along a longitudinal axis (L) and provided with a spiral (240) wound in a screw or helical configuration, A worm shaft comprising at least one helical screw conveyor unit (100) according to at least one of aspects 1 to 5 and at least one fastening means (212) configured to removably fasten to the fastening member (34). Aspect 7 7. The worm shaft according to claim 6, wherein the fastening means (212) is configured to cooperate with the fastening member (34) of the helical screw conveyor unit (100) such that the helical screw conveyor unit (100) is removably fastenable to the fastening region (40) of the worm shaft (200). Aspect 8 A worm shaft (200) according to aspect 6 or 7, characterized in that the fixing region (40) of the worm shaft (200) is shaped as follows: that is, so that radial movement of the base body (10) placed on the fixing region (40) is at least limited. Aspect 9 9. The worm shaft (200) according to at least one of aspects 6 to 8, characterized in that it has at least two fixing regions (40), which are formed by at least one recess or at least one groove in the otherwise cylindrical shaft body member (210) and are arranged radially and axially offset with respect to each other. Aspect 10 10. The worm shaft (200) according to at least one of aspects 6 to 9, wherein the shaft (230) has a cylindrical shaft body and the fixing region (40), the fixing region (40) being associated with a support region (210) of the shaft (230) configured to support the base body (10) of the helical screw conveyor unit (100), and having a smaller cross-sectional diameter than the cylindrical shaft body. Aspect 11 A worm shaft (200) according to aspect 10, characterized in that the support region (210) is arranged eccentrically, in particular, for example in a region near the end of the shaft (230), for example in the end region. Aspect 12 12. The worm shaft according to claim 10 or 11, wherein the support area (210) comprises at least two helical screw conveyor units (100) according to at least one of claims 1 to 5, the helical screw conveyor units (100) being arranged so that the helical member (30) of the helical screw conveyor unit (100) extends the course of the helix (240) of the cylindrical shaft body and together therewith forms a common shaft body helix unit. Aspect 13 13. The worm shaft according to at least one of aspects 10 to 12, wherein the worm shaft has at least two helical screw conveyor units (100), each disposed adjacent to one another and together forming one complete helical revolution around the shaft (230). Aspect 14 A worm extruder (300) for dewatering suspensions, in particular digested juices obtained by anaerobic fermentation of organic materials, comprising an extruder chamber and a worm shaft (200) having a screw-shaped helical element wound therein, the worm shaft (200) being mounted rotatably about its longitudinal axis (L) (250), 14. A worm extruder, characterized in that the worm shaft (200) is a worm shaft (200) according to at least one of aspects 6 to 13, the shaft (230) of the worm shaft (200) has at least two helical screw conveyor units (100), in particular is surrounded by at least two helical screw conveyor units (100), and the helical screw conveyor units (100) are the helical screw conveyor units (100) according to at least one of aspects 1 to 5. Aspect 15 A method of providing a worm shaft (200) configured for use in a worm extruder (300), comprising: a helical screw conveyor unit (100) according to at least one of aspects 1 to 5 is arranged in the fixing area (40), and - removably fastening the helical screw conveyor unit (100) to the fastening area (40) by means of the fastening member (34) associated with the helical screw conveyor unit (100). [Explanation of symbols] [Explanation of symbols]

[0065] 10 base body, particularly the foot member of the helical member 30 12 a first end region of the base body, in particular a first end region extending perpendicular to the longitudinal axis of the base body 14 second end region of the base body, in particular a second end region extending perpendicular to the longitudinal axis of the base body 16 Upper side, especially outer side, of the outer surface of the base body 10 18 Inside the outer surface of the base body 10 20 Radial or concave opening in base body 10 30 Spiral member of spiral screw conveyor unit 100 34 Fixing member for helical member 30 40 fixing area of ​​the base body 10, in particular a fixing area formed in a u-shape, a square element or a receiving element 42 Filling body 100 Spiral Screw Conveyor Unit 200 worm shaft or conveyor worm or extruder worm, in particular a bar-shaped worm shaft having a screw-shaped or spirally wound helical member 240, 30 210 shaft body member or support area for the worm shaft shaft 230, in particular the shaft rest area or support area for the shaft 230 of the worm shaft 200, configured to support the base body 10 of the helical screw conveyor unit 100 212 Fixing means for the shaft body member 210, especially a screw 230 has a support area 210 configured to support the shaft or bar-shaped base body of the worm shaft 200, in particular the cylindrical shaft body, and the base body 10 of the helical screw conveyor unit 100. 232 Weld seam, especially fillet seam, for connecting the cylindrical shaft body 230 to the base body 10 240 A shaft body spiral or spiral member wound in a spiral, helix or screw shape on the worm shaft 200 250 Rotary Bearing (See Figure 4) 300 Warm Extruder 340 Screen Drum 350 Press cake outlet 360 Digestive fluid inlet 370 Resistance, especially counter pressure cones L Longitudinal axis

Claims

1. 1. A helical screw conveyor unit (100) configured as a replacement part for a screw- or helically wound helix (240) of a worm shaft (200), comprising a base body (10) extending along a longitudinal axis (L), the base body (10) having two axial end regions (12, 14) and a mantle surface connecting the end regions (12, 14) to one another, on an upper side (16) of the mantle surface at least one screw-wound helical member (30) arranged, the screw-wound helical member extending radially outward from the upper side (16), the upper side (16) of the mantle surface is curved concavely in the shape of a shell about the longitudinal axis (L), and the base body (10) has radial openings (20) that are configured such that a fixing area (40) of a shaft (230) of the worm shaft (200) can be guided through the opening (20) in a direction perpendicular to the longitudinal axis (L) and can be placed in a hollow space formed by the base body (10), - said helical element (30) has at most half a helical turn; the outer surface of the base body (10) has an inner surface (18) adapted to rest on the fixing area (40); the helical screw conveyor unit (100) has at least one fastening element (34) configured for releasably fastening the base body (10) to the fastening area (40), and the inner surface (18) of the base body (10) is shaped in such a way that, as a result of the inner surface (18) of the base body (10) resting on the fastening area (40) of the worm shaft (200), the orientation of the helical element (30) of the helical screw conveyor unit (100) on the worm shaft (200) is determined and the radial mobility of the base body (10) on the worm shaft (200) is at least limited, the inner surface of the base body and the fastening area having shapes that cooperate and prevent rotational movement of the helical screw conveyor unit around the shaft.

2. 2. The helical screw conveyor unit according to claim 1, characterized in that the base body (10) extends in a semicircular or half-shell shape around the longitudinal axis (L) and is configured as a half-shell, and the helical member (30) has half a helical revolution.

3. 2. The helical screw conveyor unit according to claim 1, characterized in that for the orientation of the helical member (30) on the worm shaft (200), the inner surface (18) of the outer surface has a contour of a shape complementary to the fixing area (40) of the shaft (230).

4. 3. The helical screw conveyor unit according to claim 2, characterized in that the helical element (30) is shaped in such a way that, as a result of the inner surface (18) of the base body (10) resting on the fixing area (40) of the worm shaft (200), the helical element (30) is oriented at least substantially in the extension of the course of the helix (240) wound in the thread or spiral shape of the worm shaft (200).

5. A worm shaft (200) for use in a worm extruder (300), having a shaft (230) extending along a longitudinal axis (L) and provided with a spiral (240) wound in a screw or helical configuration, 5. A worm shaft comprising at least one helical screw conveyor unit (100) according to any one of claims 1 to 4 and at least one fixing means (212) configured to removably fix to the fixing member (34).

6. 6. The worm shaft according to claim 5, wherein the fastening means (212) is configured to cooperate with the fastening member (34) of the helical screw conveyor unit (100) such that the helical screw conveyor unit (100) is removably fastenable to the fastening area (40) of the worm shaft (200).

7. 6. A worm shaft according to claim 5, characterized in that the fastening area (40) of the worm shaft (200) is shaped in such a way that the radial movement of the base body (10) resting on the fastening area (40) is at least limited.

8. 6. A worm shaft according to claim 5, characterized in that it has at least two of the fastening regions (40), which are formed by at least one recess or at least one groove in an otherwise cylindrical shaft body member (210) and which are arranged radially and axially offset with respect to one another.

9. 6. The worm shaft according to claim 5, wherein the shaft (230) has a cylindrical shaft body and the fixing region (40), the fixing region (40) being associated with a support region (210) of the shaft (230) configured to support the base body (10) of the helical screw conveyor unit (100) and having a smaller cross-sectional diameter than the cylindrical shaft body.

10. 10. A worm shaft according to claim 9, characterized in that the support area (210) is arranged eccentrically, in an area near the end of the shaft (230).

11. 10. The worm shaft according to claim 9, characterized in that the support area (210) has at least two of the spiral screw conveyor units (100), which are arranged so that the spiral member (30) of one of the spiral screw conveyor units (100) extends the course of the spiral (240) of the cylindrical shaft body and together therewith forms a common shaft body spiral unit.

12. 10. The worm shaft of claim 9, wherein the worm shaft has at least two helical screw conveyor units (100), each disposed adjacent to one another and together forming one complete helical revolution around the shaft (230).

13. A worm extruder (300) for dewatering suspensions, in particular digested juices obtained by anaerobic fermentation of organic materials, comprising an extruder chamber and a worm shaft (200) having a helical element wound therein in the form of a screw, mounted (250) so as to be rotatable about its longitudinal axis (L), 10. A worm extruder, characterized in that the worm shaft (200) is a worm shaft (200) according to claim 5, and the shaft (230) of the worm shaft (200) has at least two of the helical screw conveyor units (100), in particular is surrounded by at least two of the helical screw conveyor units (100).

14. A method of providing a worm shaft (200) configured for use in a worm extruder (300), comprising: - a helical screw conveyor unit (100) according to any one of claims 1 to 4 is arranged in the fixing area (40), and - by means of the fixing member (34) associated with said helical screw conveyor unit (100), said helical screw conveyor unit (100) is removably fixed to said fixing area (40).

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