EP0119208A1

EP0119208A1 - Extruding machine.

Info

Publication number: EP0119208A1
Application number: EP83902419A
Authority: EP
Inventors: Raimund Falkner
Original assignee: Individual
Current assignee: Individual
Priority date: 1982-09-16
Filing date: 1983-08-01
Publication date: 1984-09-26
Also published as: AU1824183A; EP0119208B1; IT8367958A0; WO1984001125A1; IT1193148B; DE3376102D1

Abstract

Dans les extrudeuses à vis traitant en particulier des déchets combustibles, il est nécessaire d'avoir une alimentation de la matière par dosage, une pression élevée et une élimination de liquide la plus complète possible pour obtenir un rapport aussi bon que possible entre l'alimentation, la compression et la densification. A cet effet, au moins un organe de guidage qui est en contact avec l'extrémité antérieure de la vis et avec la sortie (3) voisine de la filière, permet le guidage axial de la matière extrudée pour éviter qu'elle ne se casse. La section et par conséquent la contre-pression dans un organe de rallonge (18) de la sortie de filière (3) est réglable et s'obtient de préférence par des éléments de paroi (21) extensibles et amovibles axialement grâce à l'action de ressorts. Un dispositif de dosage qui en dépend, comprend des éléments de couvertures commandés de préférence par le déplacement axial de l'organe de rallonge (18) en fonction de la pression. Ces éléments de couverture protègent une grille ou similaire disposée dans la trémie (2) entre un broyeur de la trémie (2) et l'extrémité amont de la vis. L'organe de guidage traverse la paroi (5) de la filière (1), est entraîné par la vis et nettoie constamment la sortie principale du liquide exprimé, matérialisée par la fente du support dans la paroi (5).In screw extruders dealing in particular with combustible waste, it is necessary to have a feed of the material by metering, a high pressure and the most complete elimination of liquid in order to obtain as good a ratio as possible between the feed , compression and densification. To this end, at least one guide member which is in contact with the anterior end of the screw and with the outlet (3) adjacent to the die, allows the axial guidance of the extruded material to prevent it from breaking. . The section and therefore the back pressure in an extension member (18) of the die outlet (3) is adjustable and is preferably obtained by wall elements (21) which are axially extendable and removable by virtue of the action. springs. A metering device which depends thereon, comprises cover elements preferably controlled by the axial displacement of the extension member (18) as a function of the pressure. These cover elements protect a grid or the like disposed in the hopper (2) between a hopper crusher (2) and the upstream end of the screw. The guide member passes through the wall (5) of the die (1), is driven by the screw and constantly cleans the main outlet of the expressed liquid, materialized by the slot in the support in the wall (5).

Description

SCREW PRESS

The invention relates to a screw press according to the preamble of patent claim 1.

Such a screw press is described for example in DE-A-2736810. The guide element is a longitudinal guide for the material to be pressed within the screw flights, that is, an effective in the circumferential direction is achieved that only allows axial movement of the material. Separate sieve-like outlet openings are provided for cooling the pressed-out liquid, which cannot be kept free. The screen openings inevitably become blocked, which means that the entire press has to be dismantled and cleaned. In particular, this disadvantage occurs when processing combustible waste of any composition, such as industrial waste, domestic waste, sawdust, Rixid pieces, waste paper, etc., which have a different liquid content, different particle size and different pressing properties. For example, thermoplastic waste becomes viscous to thin, so that even in small proportions they quickly move the liquid outlet openings. However, the trapped liquid causes differences in the strength of the resulting strand, so that the strand may disintegrate even after further compression. A high moisture content naturally also reduces the calorific value or the burning properties of the product if it is to be used as a fuel. The strength of the resulting strand is dependent on other factors, such as an adapting post-compression and a correspondingly metered feed, which are not dealt with in the known screw press.

The invention has now set itself the task of designing a screw press of the type mentioned in such a way that not only a constant leakage of liquid can take place and continuous strand formation with the same strength as possible is achieved, so that the best possible coordination between loading, pressing and post-compression given is. According to the invention, the essential problem of liquid leakage is now solved in that each guide element is inserted to an extent for the pressed-out liquid, which represents the longitudinal slot in the wall of the screw tube, the teeth of the guide element moving in the longitudinal slot forming cleaning elements for keeping the outlet free.

Due to the arrangement of the longitudinal slot according to the invention, through which the guide element engages with the teeth in the screw and is therefore kept in motion when the screw rotates, the longitudinal slot is constantly cleaned, so that the squeezed-out liquid can escape through the longitudinal slot of the screw tube wall at any time can.

An additional outlet for the squeezed-out liquid can be created by connecting an extension part to the screw tube beyond the mouthpiece, which is formed by at least two radially expandable wall parts which are separated from one another by longitudinal slots.

The extension part also ensures the closing of each longitudinal groove formed by a guide element in the strand during the recompression, in particular if, in a preferred embodiment, it is provided that the guide element extends into the mouthpiece over the last screw flight.

Furthermore, it has proven to be advantageous for the extension part to be spring-loaded counter to the pressing direction and to be displaceable along outer guide parts, the expandable wall parts being articulated in a radially movable manner on a slide which can be displaced on the mouthpiece.

The strand of material coming from the press cylinder of the extrusion press into the displaceable section of the mouthpiece is compressed due to its friction on the inner wall and advanced to the outlet opening, the spring acting on the displaceable section axially defining the latter on the ver sliding portion acting friction forces too large, the displaceable portion is moved against the spring in the pressing direction.

Fixed rolling bearings are preferably provided as guide parts, on which flat guide surfaces of the displaceable extension part roll.

If a pressure surface can be placed on the end of the emerging strand, which can be displaced in the pressing direction to attract a particularly adjustable counterpressure, then in a further embodiment it is provided that the screw press provides a device for canceling the counterpressure if the outlet length of the strand is equal to the length of the strand piece to be cut corresponds to a cutting device which can be used after the counterpressure has been lifted substantially perpendicularly to the strand, and has a return guide device for the printing surface in the starting position.

In the area of the hopper, which preferably has at least one wall moving towards the screw, it is further provided that the pitch of the screw flights is increased, an edge of the hopper near the screw being designed to be shear or Sri Lina-oriented. The shear or cutting element ensures that the screw is only fed well in a compressible size.

Since the metering of the material supply is also important for uniform strand compression and liquid pressure, and in particular overdosing should be prevented, it is provided in a further embodiment of the invention that the filling funnel is designed as the housing of a comminution device, in which a pair rotates in opposite directions Rolls of several interlocking and equipped with fangs discs is arranged, a grid or the like below the crushing rollers. is provided, the total passage area can be adjusted by at least one movable cover dan absorption capacity of the screw. The cover allows the passage for the shredded material to the extent required, so that overdosing is avoided. The excess material remains in the hopper and is conveyed upwards again by the slowly rotating shredding rollers, where it is returned to the material to be shredded. It then gradually falls down through the grille openings.

Since it is provided in a preferred embodiment that the distances of the comminution rollers to the grid essentially correspond to the inside width of the grid openings and to the side walls of the hopper are larger than the inside width of the grid openings, the grid has in particular a longitudinally symmetrical curved shape adapted to the rolls. To cover the grid, it is therefore particularly expedient if two covers are arranged so as to be symmetrically displaceable parallel to the grid, the

Release of the total passage cross section is preferably controlled by the movement of the slide of the expandable wall parts of the extension part. The latter enables automatic metering of the material feed into the screw.

The term "lattice" is understood to mean all components which have passages which can be used for screening purposes. For example, the grille can be formed by a perforated plate, the covers also representing perforated plates. In the closed position, each hole of the grille is covered by a material area of a cover in this embodiment. If the cover is moved, the holes in the cover increasingly slide over all holes in the grille at the same time until they are aligned with one another, thus achieving the largest passage area. The displacement of the covers is only slightly above the hole diameter.

In another embodiment it is provided that the grating consists of rods extending in one direction, and metal sheets are provided as covers which have teeth which extend along their contact edges over a plurality of rods interlock in the closed position. The grid is formed by a bar grate. If the covers are pulled apart, the gaps between the middle bars open first, and then only between the edge bars, since the direction of displacement of the covers extends perpendicular to the bars of the grid. With a displacement direction in the longitudinal extension of the bars, which is also possible, there is a longer displacement path since the filling funnel preferably has a rectangular outlet opening. It will depend above all on the design of the coupling of the displacement movements of the covers and the extension part, which displacement length of the covers appears to be the most favorable in the respective embodiment.

If the Kihrungselement for axial guidance of the strand is formed by a toothed disk driven by the worm, the teeth of which cause the cleaning of the most important liquid outlet as described, in a further embodiment it is provided in order to achieve the greatest possible axial engagement length that the toothed Disc with at least two successive teeth at the same time engages snugly in the worm, which tapers concavely in the area of engagement corresponding to the starting line of the disc. The screw preferably ends at the level of the axis of the disk, so that it protrudes by half its diameter beyond the front screw end into the mouthpiece and also forms an axial guide in this area.

Instead of the disk, it can be provided in a further embodiment of the inventive concept that the guide element is formed by at least one bar equipped with teeth and loaded towards the screw axis, which is arranged to be radially movable in the plane of the longitudinal slot, preferably the length of each tooth being at most corresponds to half the distance between the assigned pair of worm threads. While in the first-mentioned embodiment the teeth of the guide element, that is to say the disk, the evasive movement also has a large, sometimes even exclusively axial Has component, the radial component of the evasive movement is at least predominant in a strip as a guide element.

The worm threads approaching the teeth displace them radially to the outside when touching the worm axis, whereby of course also keeping the longitudinal slot free for the

Liquid leakage remains. After passing through each worm gear below the dodged tooth of the bar, it is pushed back towards the worm axis, whereby various options are available for this loading.

For example, the application of pressure springs is conceivable. However, since these would have to be of relatively large dimensions in order to be able to penetrate the space between two screw flights, which has at least partially been filled in the meantime, positive guidance is advantageous. In a preferred embodiment, this can be achieved by the worm itself, in that at least one pair of strips equipped with teeth are arranged in diametrically opposite longitudinal slots and are coupled in a radially movable manner in the same direction. Coupling the two strips of each pair results in their positive guidance. If one ledge is pushed outwards by the worm threads, the teeth of the other ledge inevitably penetrate between two worm threads on the opposite side, which are offset by exactly half the pitch. For coupling, the pair of strips can be connected on at least one side by a ring which surrounds the screw tube at a distance and is preferably guided in a displaceable manner. Such a ring can of course the strips on both. Connect the sides with each other, the depth of the screw flight being the same across the entire length of the screw.

The forced guidance of each bar can also be achieved by an eccentrically rotating driven element, the speeds of the eccentric element and the screw being the same.

A preferred embodiment kαifoiniert the above possibilities in that the ring on a roller bearing on the ex centric element is mounted, which is arranged coaxially with the screw axis.

The eccentric element can be formed on a support ring which is connected to the worm via a reinforced section of the worm thread forming a spoke. The support ring protrudes on all sides from the screw tube, which is thus divided into two parts, the inner surface of the support ring being flush with the inner surface of the screw tube, so that the annular gap interrupted by the spoke does not cause any significant change in the conveying cross section.

Here, too, it proves to be advantageous if the guide element extends into the mouthpiece over the last screw flight, so that the axially parallel guidance of the strand that is formed, which is effective as long as possible and above all also in the mouthpiece area, is achieved.

The end section of the screw with a constant pitch, which tapered evenly towards the mouthpiece for the progressive compression of the material, also makes it possible to link each bar equipped with the teeth on one side to the screw tube and to move it radially on the other side, with the bar joint moving axially the tapered end portion of the screw is offset to the outside. In this way, all teeth of the groin can penetrate equally deep between the worm threads, since in the immediate area of the groin joint, in which the swivel path would not be sufficient to allow passage of a worm gear, the radial distance from the worm is greater if the groin joint is provided on the funnel side or at an axial distance from the preferably tapered screw end if the inguinal joint is provided on the mouthpiece side.

The expandable wall parts of the connecting part can be formed, for example, by flat strips which complement one another to form the corresponding polygon if a prismatic strand is to be achieved. So the extension part between four and eight such Stripes included. However, it is also conceivable to use curved wall parts, for example quarter disks or, in particular, half disks for the extension part, so that there is a continuation of the cylindrical screw tube.

In a preferred embodiment it is provided that the guide surfaces along which the extension part can be displaced diverge in the pressing direction.

The convergence of the guide surfaces to the mouthpiece or their divergence in the pressing direction allows its radial expansion and thus a cancellation or at least reduction of the friction when the extension part is displaced, whereupon the compressed spring brings about a return movement of the displaceable extension part. The guide surfaces converging towards the mouthpiece reduce the cross section of the extension part, as a result of which the frictional forces increase again and the

Post-compression of the strand of material is increased. In this way, there is a constant change in the cross section with a very short displacement path and an essentially uniformly compressed strand is obtained which, when it emerges from the mouthpiece, is not subjected to any pressure components acting in the pressing direction, which could cause its disintegration. When a certain outlet length is reached, a strand piece breaks off due to its own weight. The compression spring, in particular a helical spring, is preferably adjustable, so that the starting position, which defines the minimum cross section of the displaceable section, can then be adapted to the material to be processed, such as industrial waste, household waste, sawdust, pieces of bark, waste paper etc. or its necessary degree of compaction. The extrusion pressure of the extrusion press can be kept smaller thanks to the reduction in extrusion friction when the spring pressure is exceeded, since it does not reach the maximum

Must overcome frictional forces. The extrusion press can thus be lighter and therefore more economical.

It has also been shown that an increasing cross-sectional enlargement towards the outlet opening of the extension part is favorable For this reason, the guide surfaces are advantageously formed in two spaced-apart rings on the displaceable section, the divergence of the guide surfaces on the outlet opening side being greater than that of the worm tube side. Rolling bearings or rollers are preferably provided as fixed guide parts, on which the guide surfaces roll during the longitudinal displacement.

At least on the outlet-side ring, each guide surface can be delimited in the longitudinal direction by projections on both sides. Of these, the screw tube side serve as end stops in the pressing direction if the spring travel of the compression spring is greater than the displacement length. The projections on the outlet opening side represent a flange on which the compression spring, preferably a pressure plate and radial roller bearings, is supported.

It is of course possible to provide the second ring of guide flat at least on the outlet opening side with such projections and to support a second compression spring thereon.

A second embodiment for post-compression, which uses the pressure face mentioned above, provides that it is formed on a piston which is acted upon by the pick-up device counter to the feed direction, the return device being designed, for example, as a compression spring which surrounds the piston rod and engages with one another adjustable abutment of the device frame supports. The piston can also be acted upon by a compressible pressure medium, for example air. In a preferred embodiment, the expandable wall parts are locked during the pressing feed of the emerging strand and opened during the ejection of the strand piece. For this embodiment, the aforementioned design of the wall parts as quarter shells is favorable, two of which are stationary in the extension of the mouthpiece and are separated by a longitudinal slot, and the two second quarter shells are each articulated to a first quarter shell. In another embodiment, the Er is in the longitudinal slot between the two quarter shells invention arranged an ejection plate to cause the ejection of the strand piece when the second quarter shells are open. In this case, a cutting plate is provided as a cutting device on the mouthpiece side of the ejection plate, and the device for canceling the counter pressure is provided on the pressure surface side, which device can be displaced perpendicularly to the strand. The actuating device for the device for canceling the counterpressure, which is formed, for example, by a displacement slide for the pressure surface with an oblique ramp surface, also displaces the cutting plate and subsequently the ejection plate, so that the counterpressure is lifted, the strand piece is separated, and finally released of the strand piece from the fixed quarter shells.

A third way to achieve the post-compression provides that the pressure surface is formed on a connecting web which extends over about half the circumference of two disks combined to form a roller, which are fixed eccentrically on a drive shaft, and their distance from one another is greater than the cross section of the emerging strand is. In the embodiment, the eccentrically arranged roller rotates over 180 to continuously evade the pressure surface, but the back pressure remains essentially the same. As soon as the rotation through 180 ° has taken place, due to the missing connecting web, the pressure on the strand is increased and the further rotation of the roller is made possible, the strand entering between the disks of the roller. The other end of the connecting step is preferably shaped into a cutting edge, so that the strand piece protruding into the roller is cut off before reaching the starting position, the counterpressure being built up again immediately thereafter. To be able to adjust the counter pressure to the required strength of the material to be pressed, it is further provided in a preferred embodiment that the drive shaft, which in particular can consist of two pins, each of which protrudes from the outside of a disk, on both sides in a carriage is rotatably mounted, each carriage rests in a sliding guide in the pressing direction on an adjustable pressure element in particular. If the roller drive is switched on when the set pressure is exceeded, exact control of the back pressure can be achieved, since the rotation of the roller then only takes place until the set back pressure is fallen below due to the backing of the pressure surface. At this moment the roller is stopped until the counter pressure is exceeded again. There is therefore a rotation of the roller divided into a plurality of small steps.

In this embodiment, the expandable wall parts are advantageously designed as half-shells which are articulated on the slide and whose movement is controlled by the roller. The control of the movement of the half-shells is achieved, for example, by providing a recess which extends approximately over half the circumference and is offset by 180 ° to the connecting web on the periphery of the outside of each disc, the half-shells being assigned positive guide rollers which are associated with one another then roll the recessed peripheral area of each disc.

It is preferably provided that the two positive guide rollers are arranged on parallel guide elements extending parallel to the half-shells, which are articulated on the slide of the extension part, each guide element being articulated to the roller-side end of the opposite half-shell. The articulated connections between the movable parts of the extension part and the slide can be designed in any suitable manner. They are preferably formed by bolts which connect the corresponding parts with radial play, with at least one contact surface being arched in each connection. A half-shell, its guide element, the slide and the connection between the half-shell and the guide element, preferably a screw bolt, represent in a preferred embodiment an articulated parallelogram which is controlled by the rotating roller and the positive guide roller arranged on the guide element. The alternate connection between a positive guide roller and a half-shell prevents their opening during the press feed, since in this phase the roller does not run in the recess of the roller disc. The pressing pressure acting on the half-shells during the pressing feed takes the extension part in the pressing direction and thereby stops it on the roller lying. It is therefore preferably provided that a roller is arranged on the outside of each half-shell at the roller-side end, which rolls on the end face of a disk of the roller. As soon as the positive guide rollers can enter the recesses in the roller disks, the pressing pressure acting on the half-shells spreads them so that they detach from the strand. As a result, the return of the extension part into the starting position is easily possible, which is done by further rotation of the roller.

The roller rotation can be controlled in various ways. In one embodiment, a control disk can be arranged on the drive shaft, which has a switching cam which extends over half the gear, which interacts with the drive of the roller, if, for example, a mechanical pressure lament (rubber buffer, compression spring, etc.) is used. The control cam of the control disk can actuate at least one limit switch of the drive motor of the roller, the accuracy of the control depending on the response speed of the limit switches, the drive or the drive brake, etc.

Another possible solution provides that the switching cam acts on a switching lever that mechanically engages the roller drive. For this purpose, it can preferably be provided that the roller drive has a worm wheel fixed on the roller drive shaft, a worm driving it, an axially displaceable intermediate shaft extending the worm drive shaft, and an output shaft rotated by the motor of the press worm, an axially displaceable between the worm drive shaft and the intermediate shaft , toothed clutch with a limit stop lying in the pressing direction and between the intermediate shaft and the output shaft of the press worm motor a friction clutch is provided when the intermediate shaft is moved in the pressing direction, and the cam-actuated shift lever axially displaces the intermediate shaft. This eliminates the need for a separate drive motor for the roller. It is of course possible to use hydraulic pressure elements instead of mechanical pressure elements, which drive the roller by means of its own motor or from the screw press motor

Control pressure relief valves. The invention will now be described in more detail with reference to the accompanying drawings, without being limited thereto.

1 to 3 show schematic views of three different exemplary embodiments, FIG. 4 shows a longitudinal section through the exemplary embodiment according to FIG. 1, FIGS. 5 and 6 show a further embodiment in two different positions, FIG. 7 shows a section along the line VII-VII in FIG. 5, FIG. 8 shows a schematic side view of an exemplary embodiment similar to FIGS. 3 or 5 and 6, FIG. 9 shows a schematic view of a fifth embodiment, and FIG. 10 shows a vertical section through the mouthpiece and the extension part, Fig. 11 shows a section along the line XI-XI in Fig. 11, Fig. 12 shows a schematic longitudinal section through a sixth embodiment in the starting position, Fig. 13 shows a longitudinal section in the end position 14 shows a section along the line XIV-XIV of FIG. 13, FIG. 15 shows a longitudinal section through a seventh exemplary embodiment in the ed 15, FIG. 17 shows a longitudinal section through the end position of the fifth exemplary embodiment, FIG. 18 shows a plan view of the illustration according to FIG. 17, FIG. 19 shows a section along the line XIX -XIX of FIG. 14, FIG. 20 shows a schematic illustration of the drive of the post-compression device according to FIGS. 15-19 via the motor of the press screw, FIG. 21 shows a vertical section through an embodiment of the filling funnel according to line XXI-XXT of FIG. 1 and FIG. 22 is an enlarged bottom view of an embodiment of the grille cover of the hopper.

Invention screw presses are particularly suitable for sealing all kinds of combustible waste and have a screw tube 1 with a screw 6, a hopper 2 above one end of the screw 6 and a mouthpiece 3 which is located at the other end of the screw 6 Screw tube 1 connects. The screw 6 is provided with screw flights 7, which are in the area between the feed hopper 2 and the mouthpiece side End have a flat slope, while they rise much steeper in the area of the hopper 2. The hopper 2, not shown in detail, is, for example, of a truncated pyramid shape, with at least one of the hopper walls 22, for example, having conveyors moving in the direction of the screw 6, for example a conveyor belt or the like equipped with drivers. are provided. Other structural designs of the hopper are shown in FIGS. 21 and 22. One of the edges 19 of the hopper 2 close to the screw is arranged at a distance from the screw 6, which corresponds to the maximum size of the material to be pressed that can be grasped by the screw 6, and serves as a shear element for the material to be processed, the edge 19 in the direction of rotation of the Snail 6 points. The materials fed through the hopper 2, for example plastic, cardboard or wooden packaging, waste paper, food waste from commercial operations, pieces of bark, sawdust and wood waste from sawmills, straw, brushwood and other waste from agriculture etc. are supported by the preferred funding the funnel wall 22, gripped by the worm threads 7 of the worm 6 running in this area with a large gradient, torn by the Scherelanent and conveyed into the worm tube 1. Instead of or in addition to the Scherelanent, an edge 19 of the hopper 2 pointing against the direction of rotation of the screw 6 can also be designed as a cutting edge. The material to be pressed is then compressed in the screw tube 1 in which the screw flights 7 are continued with a smaller and, for example, constant pitch, the liquid contained, in particular water, which can be a relatively large proportion depending on the material, being released. At least one longitudinal slot 4 in the wall 5 of the screw tube 1 is used to discharge the squeezed liquid, while that compresses to one strand

Material leaves the mouthpiece 3 coaxially with the screw axis 12. After leaving the screw press, this strand 10 breaks into handy parts or, if appropriate, is also divided into parts which have a transportable strength and can be used as fuel with a medium to high calorific value. With material-related fluctuations, this lies approximately in the Height of lignite briquettes, the strand parts also having approximately similar combustion properties.

A progressive compaction of the material is necessary in order to achieve a higher degree of dewatering with strong, water-containing waste, for example with pieces of bark that previously had to be pre-dried during briquetting. In the exemplary embodiments according to FIG. 3 or 5 to 8, this could also be achieved by continuously reducing the pitch of the screw flights 7. However, it is also more favorable in these exemplary embodiments, in the two other exemplary embodiments according to FIGS. 1/4 and 2, it is necessary to keep the slope constant. At least the end section 20 of the screw 6 is therefore tapered towards the mouthpiece 3. In order to ensure a longitudinal guidance of the material to be pressed, also in the tapered end section 20 of the screw 6, at least one guide element 9 is provided which engages between the screw flights 7 and thus, seen in the circumferential direction, a positive connection between the strand 10 and the screw tube which is formed 1 results. For this purpose, each guide element 9 is equipped with teeth 8, 37 and is designed to be movable in a radial plane of the screw axis 12, so that it can avoid the migrating screw flights 7. The radial plane runs through the longitudinal slot 4 in the wall 5 of the screw tube 1, so that the guide element 9 can be mounted on the outside of the screw tube 1. Due to the constant movement of the guide element 9, the longitudinal slot 4 is also kept constantly free and its clogging by the material, which would prevent the liquid from escaping. The worm 6 also ends on the mouthpiece side at a distance from the mouthpiece 3, and the guide element 9 projects beyond the worm 6, so that the guiding action of the guide element 9 is maintained approximately directly up to the mouthpiece 3.

1 and 4, the guide element 9 is formed by a toothed disc 11 which is arranged loosely rotatable on the axis 42. The rotating screw 6 therefore drives the disk 11 provided with teeth 8, which on the one hand cleans the longitudinal slot 4 and on the other hand forms a longitudinal guide for the material. The taper of the end portion 20 of the screw 6 is concave to the extent of Adjusted disk 11 so that several teeth 8 of the disk 11 engage snugly in the screw 6.

The longitudinal slot 4 can be made substantially longer than shown and, if necessary, a further disk 11 provided with teeth 8 can also be provided at a distance from the front disk 11 in order to increase the length of the guide element 9. In this case, the worm 6 has a further concavely curved, tapering section.

2, the tapering of the screw 6 is constant over the entire length of the screw tube 1 and a circumferential chain 13 is provided as a guide element 9 in the longitudinal slot 4, the links of which are also equipped with teeth 8. The chain 13 is guided over two deflection rollers 23, 24, the oil steering roller 24 near the mouthpiece being arranged directly at the mouthpiece 3 before the end of the screw 6. The teeth 8 of the chain 13 now engage between two screw flights 7 and in turn bring about the axial or longitudinal guidance of the material to be pressed, as well as the keeping of the longitudinal slot 4. The chain 13 is also loosely rotatably supported and is rotated by the rotating screw 6 driven.

3 and 5 to 7 show a third and fourth embodiment of the screw press according to the invention. According to FIG. 3, the guide element 9 is formed by a bar 14 which is rigid in the longitudinal direction and on which teeth 8 are provided, which in turn engage between the screw flights 7. Since the teeth 8 of the bar 14 must also dodge, but an axial movement of the teeth 8 is not possible, the bar 14 is arranged to be movable essentially radially or perpendicularly to the surface of the screw, with a corresponding displacement of the teeth 8 in this case as well is achieved by the rotating screw 6. An additional device is, however, for the return of the bar 14 after the passage

Worms 7 on the teeth 8 required. The kick of the bar 14 towards the screw axis 12 can be achieved by an eccentrically rotating element 15, the speed of which is equal to the screw speed. The eccentric element 15 can thereby a cam disk or camshaft can be formed, which bears against the bar 14 from the outside, the nooke causing the bar 14 to be returned. For example, such a cam could be arranged at each end of the bar 14.

3 surrounds the eccentric

Element 15, the screw tube 1 on the hopper side and is driven at the same speed in a manner not shown. On the eccentric element 15, a roller bearing 17 is arranged, which is enclosed by a ring 16, from which a tab 26 projects radially. This is loosely penetrated by a bolt 25 which is provided on the bar 14. The protruding into the tab 26 bolt 25 prevents the entrainment of the ring 16 when the eccentric element 15 rotates, so that the ring 16 orbits the screw axis 12 eccentrically without self-rotation. Since a second degree of freedom is advantageous for the circular movement of the ring 16, the tab 26 is preferably only pivotable to a limited extent ver arranged on the ring 16 which extends to the screw axis 12. The movement of the eccentric element 15 therefore presses the bar 14 and thus its teeth 8 alternately radially outwards and inwards. The area of the bar 14 close to the tooth, insofar as it engages in the longitudinal slot 14, with unevenness such as ribs, sharp-edged projections 38 or the like which supports the cleaning of the longitudinal slot 4. be provided. Such a guide for the bar 14 can be provided at both ends. For the sake of simplicity, however, the bar is articulated at the other end, in the exemplary embodiment on the mouthpiece side, so that its movement represents a pivoting movement about the joint axis 28. The bolt 25 is therefore, as mentioned, arranged in the bracket 26 with some play and therefore movable and longitudinally displaceable so as not to hinder the swiveling movement.

In the embodiment according to FIGS. 5 to 7, which is designed in the same way as the embodiment according to FIG. 3 with regard to the strip 14 as the guide element 9, the eccentric element 15 does not surround the screw tube 1 as a separately driven component, but is formed on a support ring 32 , which is connected to the screw 6. The Screw tube 1 is interrupted in this area, ie divided into two parts, and the support ring 32 protrudes outward from the conveying space of the screw 6. The inner surface of the support ring 32 is aligned with the inner wall of the worm tube 1 and the connection between the support ring 32 and the worm 6 takes place via the reinforced section 33 of the worm gear 7, which consequently forms a type of spoke (FIG. 7), so that the conveying cross section is only slightly reduced. Since in this connection area between the support ring 32 and the screw 6 the material to be pressed would inevitably co-grow in the circumferential direction, a further guide element 9 in the form of an angled lever 36 is provided in this embodiment, which is attached to a screw tube fixed and an outer bearing 34 for the support ring 32 the part of the screw press is articulated. The lever 36 extends on the side of the support ring 32 facing the feed hopper 2 into a further longitudinal slot 4 of the wall of the screw tube 1 and is equipped with a tooth 37 which engages in the space 41 between the support ring 32 and the screw 6 at a slightly inclined angle to the screw axis 12 has a long length, since the slope of the screw flights 7 in the feed area, as mentioned, is high. The other end of the lever 36 is provided with a longitudinal slot through which a guide pin provided on the bracket 26 extends, the bracket 26 being pivotable about the axle pin 27. A roller bearing 35 is provided between the support ring 32 and the outer bearing 34. Between the support ring 32 and the screw tube 1, an annular gap 40 is also provided on both sides, through which liquid which has also been squeezed out can escape. To clean the annular gaps 40, as can be seen from FIG. 7, the adjacent area of the eccentric element 15 or the support ring 32 is also provided with unevenness, such as sharp-edged ribs, or cutting edges 39, which can additionally be bent.

Fig. 5 shows in longitudinal section the pivoted-out position of the bar 14, in which the screw flights 7 are arranged below the teeth 8 and at the same time the lever 36 is pivoted in with the tooth 37. 6, on the other hand, shows the pivoted-in position of the strip 14, in which the teeth 8 engage between the worm threads 7, and the pivoted-out position of the lever 36, in which the tooth 37, the worm thread 7 and let section 33 pass. The teeth 8, 37 preferably have a length which corresponds to approximately half the pitch, so that there is sufficient play. The hinge axis 28 is arranged closer to the mouthpiece 3 than the front end of the worm 6, so that the teeth 8 can all be formed with the same depth, since a sufficient distance from the worm 6 is already achieved with the first tooth 8 engaging between the two foremost worm threads 7 , which allows the passage of the worm gear 7.

The arrangement or guidance shown of the bar 14 could also be reversed, so that the hinge axis 28 on the side of the hopper 2 and the ring 16 and the eccentric element 15 is on the mouthpiece side. Even with such an embodiment, there are no obstacles to the pivoting movement if the hinge axis 28 is arranged closer to the filling funnel 2 with respect to the tapering section of the screw 6.

In all of the embodiments described, it is also possible to arrange a plurality of guide elements 9 distributed over the circumference. 8, the formation of a further strip 14 on the side of the screw tube 1 diametrically opposite the first strip 14, in whose wall 5 a further longitudinal slot 4 is provided, is particularly favorable. The two strips 14 can be coupled in a simple manner through the ring 16 and the two tabs 26 and attached to two parallel joint axes 28. In this embodiment, the formation of an eccentric element 15 is not absolutely necessary, since the two strips 14 force each other. For this purpose, the ring 16 must surround the screw tube 1 with a sufficient distance. In this case, the teeth 8 ′ of the two strips 14 are arranged exactly opposite one another, with one strip 14 (the upper one in FIG. 7) being pivoted in by the half displacement of the screw flights 7 and the other strip 14 being pivoted out, the teeth 8 thereof just be passed by the worm gear 7. Here, the rotation of the worm 6 in turn causes the drive of the coupled strips 14, since the worm threads 7 alternately displace the teeth 8 of the two strips 14, which are displaceable in a common plane. Since an eccentric element 15 is not absolutely necessary, can also on the support ring 32 can be dispensed with. The lever 36 can of course still be provided.

Instead of the articulation of the two strips 14 according to FIG. 7, a coupling by a ring 16 and tabs 26 can also be provided on this side.

Following the mouthpiece 3 there is further provided an extension part 18 composed of individual wall parts 21 arranged at a distance to form longitudinal slots 29. The wall parts 21 are individually radially adjustable, for which purpose, for example, a ring 30 is provided which is penetrated by adjustable bolts 31 which bear against the wall parts 21. By means of the extension part 18, a radial compression of the strand 10 emerging from the mouthpiece 3 is achieved, which is adjustable. Post compression can be used depending on the material. If, on the one hand, very dry waste, such as paper wool or wood wool, or, on the other hand, very wet waste, the drainage of which has not been completely carried out in the screw tube 1, is pressed, the strength of the strand 10 is usually too low, and this disintegrates into small parts when it emerges. 1-8, the expandable wall parts 21 are individually adjusted so that a further cross-sectional taper is achieved. This also compensates for the grooves in the strand formed by the guide elements 9 and sufficiently compresses the strand 10. Post-compression by tapering the cross-section can be unnecessary if the waste contains a large proportion of thermoplastic materials, which melt during the compression in the screw press and mix intimately with the remaining material due to the screw movement.

The setting of the post-compression can also be automated, as will be explained using the next drawing figures. According to FIGS. 9-11, a Rafonen 60 is provided in this embodiment with a side plate 65 which adjoins the screw tube 1 and which carries the extension part 18. As can be seen in more detail from FIGS. 10 and 11, the extension part 18 has a displaceable section 43 Mistake. This has a slide 49 on the press side, which is slidably arranged on the end region of the screw tube 1, ie on the mouthpiece 3. On the carriage 49 several, for example six strip-shaped flat wall parts 21 are articulated, for example by means of screws 51 which penetrate them with play, which complement each other to form a tube with a hexagonal cross section. Continuous longitudinal slots 29 remain over the entire length between the wall parts 21, which also allow the liquid squeezed out of the material to exit.

To guide the displaceable section 43, at least two wedges 55 are fastened at a distance from one another on each wall part 21, the outer surfaces of which form flat guide surfaces 44, 45 and each diverge on the outlet side. During the longitudinal displacement of section 43 in the direction of the double arrow B, the guide surfaces 44, 45 roll on stationary rolling bearings 52 or rollers. The wedges 55 are arranged in rings 61 and the roller bearings 52 in cages 53, the angle of the guide surfaces 44, 45 to the pressing direction A being different. The outlet-side guide surfaces 44 run, for example, at an angle of 5, the screw-tube-side 45 at an angle of 1 ° to the pressing direction A.

On the rim 61 of the guide surfaces 44 on the outlet opening, projections 54, 56 of the wedges 55 protrude outward on both sides in the longitudinal direction. The projections 54 on the screw tube side form a sliding stop for the section 43 of the extension part 18 in the pressing direction A. The projections 56 on the outlet opening side of the wedges 55 complement one another to form a flange on which a compression spring 59 is supported. A pressure plate 58 and radially movable roller bearings 57 are provided between the compression spring 59 and the projections 56. The compression spring 59 is supported on the outlet opening side against an abutment 63 arranged longitudinally adjustable on the frame 60, so that the spring travel of the compression spring 59 can be changed with the aid of the nuts 62.

The waste material to be pressed into the strand 10 is pressed by the screw 5 through the mouthpiece 3. Through to the wall share 21 resulting friction there is an increasing compression of the material strand 10, which exits at the outlet opening 66 and breaks off into handy pieces due to its own weight. The length of the extension part 18 corresponds approximately to 10 to 20 times the strand diameter.

If the compression pressure becomes too high due to the different compression properties of the material to be processed and thus the frictional forces, which could lead to an interruption of the feed and possibly damage to the press, the section 43 of the extension part 18 moves under compression of the compression spring 59 in Pressing direction A with the material strand 10, with the slide 49 sliding on the end section of the screw tube 1 or mouthpiece 3. The guide surfaces 44, 45 roll on the roller bearings 52 since they are pressed against them by the radial pressure of the material strand 10. The divergence of the guide surfaces 44, 45 now causes an enlargement of the mouthpiece cross-section when the section 43 is displaced, so that the frictional forces and the compression become smaller and the feed of the material strand 10 is maintained or increased slightly. At the same time, the compressed compression spring 59 moves the displaceable section back again, the cross section of the extension part 18 being reduced by the divergence of the guide surfaces, the frictional forces being increased and the compression of the material strand 10 being increased.

If, on the other hand, the pressing pressure is too low to ensure sufficient strength of the material strand 10, the section 43 is pushed even further onto the mouthpiece 3 by the compression spring 59, so that the cross section of the section 43 at the outlet opening 66 is also smaller than the cross section of the Mouthpiece 3 can be, whereby the compression of the strand 10 is increased.

A constant forward and backward shift occurs with a simultaneous change in cross-section, which results in a strand of essentially the same strength. The change in cross section decreases as the distance to the slide 49 decreases, since the wall parts 21 are hinged to this. However, the frictional forces also increase on the outlet opening side, so that the largest cross-sectional change is favorable there. The crown 61 of wedges 55 on the side of the screw tube can therefore have contact surfaces 45 with a smaller angle than the guide surfaces 44 to the pressing direction A. The auger tube-side rim 61 is used in particular for the longitudinal stiffening of the expandable wall parts 21, so that they can be made of a thinner material and bulges are kept out.

If necessary, a central ring 61 with guide surfaces and a central cage 53 with roller bearings 52 could also be provided to support the wall parts 21. The adjustment of the abutment 63 could also be automated, with different setting levels for certain compositions of the waste to be processed can be provided.

12 to 20, which automatically adapt themselves to the compression pressure and subsequently achieve the desired degree of strength of the strand 10 to be obtained, or strand pieces 72, shown in FIGS For the strand 10 entering the extension part 13, a counterpressure device 73 with a pressure surface 74 abutting the end face of the strand 10, a device 75 for canceling the counterpressure after the desired strand outlet length has been reached, a cutting device 76 which can be used after the counterpressure has been canceled, and which simultaneously cuts off the cut strand piece 72 ejects, and a return device 77 for returning the pressure surface 74 to the starting position, in which it is pressed against the end face of the strand 10, is provided. 12-14, in which only the foremost section of the screw press

Auger 6 is shown in the area of the mouthpiece 3, the extension part 18 follows in the form of a cylindrical part which is composed of quarter shells 86, 87 over the length of the strand section 72 to be produced. The first two quarter shells 86 preferably form the upper half of the cylindrical part with horizontal pressing direction A and are immovably arranged in the extension of the mouthpiece 3. A longitudinal slot 88 extends between the two quarter shells 86. The two second quarter shells 87 are each movably connected to the two first quarter shells 86 via a joint 89 and are held in contact with one another by a locking device (not shown) during the pressing advance of the strand 10 (FIG. 12 ). After the desired strand exit length has been reached, the lock is released and the two second quarter shells 87 are opened (FIGS. 13 and 14), so that the strand piece 72 to be cut can exit laterally, preferably downwards. An ejector plate 94 acts as an ejector, which is inserted into the longitudinal slot 88 and retracted so far that it does not protrude into the cylindrical space 92. The cutting device 76 is arranged on the mouthpiece side of the longitudinally extending ejection plate 94 in the form of a cutting plate 95 perpendicular to the direction of the strand and is guided in corresponding transverse slots 96 (FIG. 12) of the first quarter shells 86. At the other end of the ejection plate 94, the device 75 for canceling the counter pressure is designed in the form of a displacement slide 95, which projects beyond the lower edge of the ejection plate 94 and has an inclined run-up surface 97.

The counterpressure device 73 with the pressure surface 74 is accommodated in a tubular extension section 91 which adjoins the hollow cylindrical part consisting of the quarter shells 86, 87 and forms a fixed part of the frame 60. The pressure surface 74 is provided on the end face of a piston 81 which is guided axially displaceably via a piston rod 82. A compression spring 59, which also serves as a return device 77, presses the pressure surface 74 against the end face of the strand 10 and is supported on an abutment 63, preferably axially adjustable by means of screws 98, which are arranged rotatably in the frame 60.

To produce the strand pieces 72, the compression spring 59 is increasingly compressed by the strand 10 pressed out of the mouthpiece 3. The quarter shells 86, 87 support the emerging strand 10 circumferentially against buckling. As soon as the desired outlet length has been reached, the displacer disk 95 is set in motion, the contact surface 97 of the displacer slide 59 pressing so that it detaches from the end face of the strand. Subsequently, the cutting plate 93 begins to separate the strand piece 72, the second quarter shells 87 opening, and subsequently the strand piece 72 is ejected by the advance of the ejection plate 94. The displacement slide 95, the cutting plate 93 and the ejection plate 94 then pull back again, the second quarter shells 87 are closed and the released one

Pressure surface 74 is pressed forward under the action of the compression spring 59 against the end face of the strand 10.

While the device according to FIGS. 12-14 increases the back pressure acting on the strand 10 with increasing outlet length, the exemplary embodiment according to FIGS. 15-19 shows an embodiment of the device according to the invention in which the back pressure during the press feed of the strand 10 remains essentially unchanged. In this embodiment, too, the essential components, namely the counter pressure device 73 with pressure surface 74, the device 75 for canceling the counter pressure, the cutting device 76, the return device 77 of the pressure surface 74 and the extension part 18 are provided. The most important component of this variant is represented by a roller 100, which is composed of two side disks 101 and a connecting web 102 extending approximately over half the circumference of the disks 101, the outer surface of which forms the pressure surface 74. The roller 100, the disks 101 of which are at a distance from one another which is greater than the diameter of the strand piece 72 to be cut off, is fixed eccentrically on a shaft running perpendicular to the pressing direction A, which is preferably formed from two pins 103, but can also be formed continuously . A sliding guide 104 is provided on each side of the roller 100, each of which receives a slide 119, the two pins 103 each being rotatably mounted in a slide 119. Each carriage 119 rests on a pressure element 105, for example a rubber buffer, a compression spring cdgl. on. On one of the two pins 103, a control disk 106 is also fastened, which cooperates via a switching cam 117 extending over half the circumference with two limit switches 118, which control the drive 107 of the roller 100, which is coupled to the second pin 103. The pressure element 105 is preferably adjustable, as is the position of the limit switches 118, in order to be able to adjust the counterpressure to be applied to the strand 10 approximately uniformly, depending on the type and moisture content of the material to be pressed.

To support the emerging strand of material 10, expandable wall parts 21 are also provided in this embodiment, which consist of two half-shells 108. The two half-shells 108 are articulated on the face of the carriage 49, which is displaceable on further guides 116, preferably arranged in the extension of the slide guides 104. On the roller side, a roller 112 is rotatably arranged on each half-shell 108, on which the side plates 101 of the roller 100 roll. Parallel to each half-shell 108, also articulated to the slide 49, extend guide elements 109, on the front end of which a positive guide roller 111 is rotatably supported, which abuts the periphery of a side window 101. In the contact area js of the positive guide roller 111, a recess 113, in particular a groove, is made in the side window 101 over the ecden area over which the connecting web 102 forming the pressure surface 74 does not extend. When the roller 100 rotates, the positive guide roller 111 therefore runs over approximately 180 in the recess 113 and over the remaining active area on the outer surface of the side window 101 itself. This causes an alternating occupation of each guide element 109, from which the upper and lower connecting bolts 110 close of the respective opposite half-shell 108 of the extension part 18 for the strand 10. The shells 108 are therefore held in contact with one another during a roller rotation, as long as the positive guide rollers 111 do not roll in the recesses 113 but on the side window 101 itself, and spread apart as soon as the positive guide rollers 111 have entered the recesses 113. The ex Centricity of the roller 100 to its drive shaft is half the length of the strand piece 72 to be cut, a change in length being possible by radial adjustment of the pins 103 on the roller 100 and displacement of the associated pressure elements 105 in the pressing direction A. The facilities required for this are

However, not shown for clarity. The densification of the strand 10 and separation of the strand pieces 72 now takes place in the following manner: from the starting position shown in FIGS. 15, 16, in which the slide 49 of the extension part 18 is arranged in the position closest to the screw tube 1, and in which Connecting web 102 of the two side disks 101 closes the front of the extension part 18, the roller 100 is displaced from the emerging strand 10 in the pressing direction A under the action of the pressing pressure of the screw 6 until the counterpressure set on the pressure element 105 is reached, with its two carriages 119 in move the two slide guides 104. When the desired back pressure is reached, the switching cam 117 on the control disk 106 switches on the drive 107 of the roller 100, which starts rotating. Due to the eccentricity of the roller 100 and thus the pressure surface 74, the distance between the pressure surface 74 and the mouthpiece 3 increases by a certain amount, so that the strand 10 can emerge by this partial length. Since the counterpressure is thereby briefly reduced, the pressure elements 105 move the roller 100 again against the pressing direction A, as a result of which the switching cam 117 of the control disk releases the switch 118 again. The drive 107 is interrupted and the roller 100 stops. The pressing pressure of the screw 6 then increases again, so that the roller 100 is moved again in the pressing direction A, the pressure elements 105 are compressed again more intensely and finally the drive 107 is switched on again in the manner described. In this way, a stepped rotation of the roller 100 over approximately 180 is achieved with substantially constant back pressure on the strand 10, the end position being shown in FIGS. 17 and 18. The expandable wall parts 21 of the extension part 18 are inevitably held on the side disks 101 of the roller 100 by the emerging strand 10 itself. From Fig. 15 it can be seen that the two Half-shells 108 of the extension part 18 enclose the mouthpiece 3, there being a small distance between the pressure surface 74 and the mouth of the mouthpiece 3. The strand 10 entering this slightly enlarged space 120 relative to the mouthpiece 3 is pressed radially by the counterpressure against the half-shells 108, which are each held in the closed position by the positive guide roller 111 running in the curved piece between the recess 113 and the side window 101 via the connecting bolts 110 become. As the strand 10 emerges, the radial pressure now creates a frictional connection to the half-shells 108, which are prevented from moving laterally by the positive guide rollers 111, so that the extension part 18 is carried along by the strand 10. The rollers 112 of the extension part 18 therefore rarely remain attached to the forehead of the side windows 101 during the entire press feed, so that when the end position is reached according to FIGS. 17 and 18 of the extension part 18, a tubular extension to the extent of the length of the strand piece 72 to be cut off, i.e. the double eccentricity of the side windows 101 forms.

As soon as the end of the connecting web 102 (FIG. 17) has released the end face of the emerging strand 10, the counter pressure is released and the roller 100 moves due to the pressure elements 105 into its unloaded position against the pressing direction A, whereby by the 15 and 16, a second switch 118 is actuated, which also causes the roller 100 to rotate continuously through its remaining angle, so that it is returned to the starting position according to FIGS. With the release of the strand end, the positive guide rollers 111 enter the grooves or recesses 113 on the side window 101, so that the half-shells 108 can be expanded. This also takes place automatically due to the radial pressure generated in the strand, which leads to the removal of the conclusion of the conclusion of strand 10. The onset kick rotation of the roller 100, in which the end faces of the side disks 101 approach the mouthpiece 3 again, pushes the one that has exited Strand detached extension part 18 back on the mouthpiece 3. The extruded strand 10 penetrates between the side disks 101 into the roller 100 and is exposed there. The end of the groove 113 is reached immediately before the starting position is reached, as a result of which the positive guide rollers 111 are lifted off and the half-shells 108 are pressed together again. Furthermore, at this time the severed free strand 10 is cut off by the cutting device 76, which is formed by a cutting edge 121, into which the front end of the connecting surface 102 forming the pressure surface 74 runs out. When the strand 10 is cut and the strand section 72 is ejected, the pressure surface 74 begins to bear against the web and the counterpressure builds up, the switching cam 117 releasing the second switch 118 and the roller 100 standing still. It is now moved again in the pressing direction A together with the extension part 18, and the counterpressure is built up, the further rotation of the roller 100 being controlled in the described manner in small steps by the compression and decpression of the pressure elements 105.

The articulated connection between the slide 49 of the extension part 18 and the half shells 108 and the guide element 111 carrying the positive guide rollers 111 is given in a simple manner by fastening screws 114 arranged with play, the end faces of the half shells 108 and the guide element 109 resting on the slide 49 are slightly fcαnbiert to allow a rolling movement.

20 shows a variant of the control of the roller drive. 15-19, if a separate motor, not shown, is provided as the drive for the roller 100, the drive of the press worm 6 takes place in this embodiment. The drive shaft or a drive pin 103 is located next to the control disk 106 another worm wheel 123 is fixed, in which a gear worm 124 engages. The gear worm 124, which also moves with the slide 45, has a worm drive shaft 126 which, via an axially displaceable toothed coupling 133, has an axially displaceable intermediate shaft 125 is coupled. The switching cam 117 of the control disk 106 moves a switching lever 122 articulated on the frame 60, the movement of which axially displaces the intermediate shaft 125, a compression spring 130 supported on the frame 60 acting on a pressure disk 132 fixedly connected to the intermediate shaft 125 via a thrust bearing 131. This compression spring 130 is compressed by the switching cam 117 when the switching lever 122 is actuated. At the other end of the intermediate shaft 125, a clutch disc 127 of a friction clutch 129 is arranged, which interacts with a second clutch disc 128. This clutch disc 128 is preferably driven by a gear from the motor of the press screw 6. The axially displaceable coupling 133 has a coupling sleeve 140 provided with an internal toothing 137 and a front limit stop 136 in the pressing direction. A gear 139 fixed on the worm drive shaft 126 slides in the internal toothing 137. As soon as the gear worm 124 with the roller 100 mounted in the slide 49 is displaced by the pressing pressure, the clutch 133, the coupling members of which lie against one another in the front end position shown, also the intermediate shaft 125 is displaced, so that when the set counterpressure is exceeded, the friction clutch 129 engages and the roller 100 is rotated. The deflection of the pressure surface and falling below the set counterpressure disengages the clutch 129, since the intermediate shaft 125 can be pushed back again by the compression spring 130. Immediately before the maximum strand exit length is reached and the counter-pressure has to be eliminated and the roller 100 has to be turned back quickly, the switching cam 117 of the control disk 106 is in the position shown in FIG. 20. In the last counter-pressure controlled rotation step that is still required, the switching cam 117 now actuates the switching lever 122 which can be rotated about the axis 134, the claw 138 of which comprises the intermediate shaft 125 and abuts the internally toothed sleeve 140. This also attracts the intermediate shaft 125 and engages the friction clutch 129, the gear wheel 139 being axially displaced in the toothing 137.

Due to the pressure and the back pressure, an adjustable high compression of the strand 10 is achieved, so that one sufficient strength of the material is achieved. Escaping water flows out of the screw press mainly through each longitudinal slot 4 in the wall of the screw tube 4, in which the guide element 9 is arranged, and through the longitudinal slots 29 between the flat expandable wall parts 21 according to FIGS. 1-11, and also Slits between the quarter shells 86, 87 (Fig. 12-14) or half shells 108 (Fig. 15-19) of the extension part 18. Through

Profiling the inner surfaces of the shells 86, 87, 108, the cross-sectional shape of the strand pieces 72 can be determined. The preferably compressed combustible waste material is therefore, regardless of its moisture content, compressed to transportable press briquettes with sufficient strength and high calorific value.

21 and 22, as mentioned, a preferred embodiment of the filling funnel 2 is explained in more detail. The filling funnel 2 has two vertical side walls 156 and two side walls 146 widening after the filling opening 148. In the two vertical side walls 156, two drive shafts 142, 143 of a shredding device 149 are mounted, each of which is equipped with a slowly rotating shredding roller 150, which is composed of shredding disks 144 provided with fangs 145. The shredding disks 144 are axially grounded at a distance from one another which corresponds to the width of a shredding disk 144, the shredding disks 14 of one shredding roller 150 engaging those of the other shredding rollers 150. The two shredding rollers 150 rotate in opposite directions, so that the waste filled in via the filling opening 148 is passed between the shredding disks 144 of the rollers 150 and thereby shredded. Provided below the comminution device 149 is a grid 147, for example a sieve, a perforated plate or a bar grate, which has openings 157 corresponding to the desired size of the comminuted material particles.

The amount of material shredded by the shredding device 149 and fed to the screw press 6 below it can now be too large, which also results in too little Compression of the strand 10 and thus disintegration of the strand pieces 72 would occur. A, preferably two-part cover 151 on the underside of the grating 147 ensures the correct metering of the amount of shredded material passing through the grating 147. To avoid material jams, the distance between the grating 147 and the shredding rollers 150 is approximately as large as the size of the shredded pieces of material and the distances between the comminution rollers 150 and the inclined side walls 146 are chosen to be larger than the size of the comminuted material pieces, and furthermore each comminution roller 150 is assigned a series of wipers 152 which each extend obliquely in the direction of the center web 153 extending below the comminution device 149 Drive shafts 142, 143 extend between the shredding disks 144. To achieve the mentioned distance of the grid 147 to the comminution rollers 150, this is therefore symmetrical

Roll circumference adapted bent, wherein it is supported in the middle by the central web 153. The two covers 141 are therefore also correspondingly curved.

If the amount of material falling through the openings 157 of the grille 147 cannot be absorbed by the screw 6 without loss of strength of the strand 10, the overall passage area of the grille 147 is reduced by shifting the covers 151. This can be done manually, but is preferably coupled with the change in the outlet cross section of the extension part 18, in particular with the axial displacement given in the embodiments according to FIGS. 9-19.

In FIG. 21, both the grid 147 and the covers 151 are formed by perforated metal sheets, the latter being able to be displaced by the hole diameter in the direction of the arrows from the closed state shown. As a result, all of the openings 157 in the grille 147 widen at the same time, and the displacement path is short.

22, on the other hand, shows a different design in a view from below, that is to say from the side of the screw 6. Here, the grid 147 is formed by parallel bars 154 of a grate, so that it can be seen as Openings 157 provide slots extending lengthways. The covers 151 are in turn formed by metal sheets which, in the closed state, also engage under the central web 153 carrying the wipers 152 and have a toothing along their contact edges, for example the teeth 155 shown, which, in the closed state, completely close the mesh 147 in the closed state. With increasing pull-out movement of the cover, the openings 157 are gradually opened from the center, FIG. 22 showing a central position. As shown, the covers 151 can be moved perpendicular to the bars 154, but also parallel to them.

If the amount of material between the shredding device 149 and the grating 147 is greater than the amount that can be fed to the screw 6, the shredded material is taken along by the shredding rollers 150 again into the filling funnel 2, or is circulated until the total cross-sectional area of the grating 147 is enlarged. Any further comminution that may take place during this time is of no importance; however, a dosage which is essentially adapted to the absorption capacity of the screw 6 is achieved in a simple manner.

A variant of the embodiment shown in FIGS. 9-11 provides an immovable extension section 18, the expandable wall parts 21 having legs which are angled outwards on the mouthpiece side and which are articulated on the frame 60. On the side of the outlet opening 66, a radially acting compression spring can now be provided for each wall part 21, which, when the radial pressure of the strand 10 increases, allows the wall parts 21 to pivot slightly outwards and returns them inwards as the radial pressure decreases. Instead of the radially acting compression spring or in addition, an axially acting compression spring can also be provided, which is supported on the angled legs which essentially complement one another to form a flange. In this way, a shorter overall length is achieved in any case, since the front abutment 63 is omitted.

The exemplary embodiments shown in FIGS. 9-22 are not limited to the use of a screw 6 for generating the press feed. They can also be designed as piston extrusion presses.

Claims

Claims:

1. Screw press for the production of strand-shaped pieces of pressed material with a simultaneous reduction in the liquid content of the material, with a screw with at least one toothed guide element for the strand, whose teeth in the

Intervene screw flights and avoid them when the screw rotates in an axial plane, with a screw tube having an axial mouthpiece for the pressed material and a filling funnel, and in the wall of which at least one side outlet for the pressed-out liquid and a longitudinal slot are provided through which the guide element protrudes into the screw tube, the screw tube tapering towards the mouthpiece and characterized by a device for exerting a pressure counteracting the pressing pressure on the strand emerging from the mouthpiece, which is preferably adjustable to adapt to the desired strength of the pressed material that each guide element (9) is inserted into an outlet for the squeezed liquid, which represents the longitudinal slot (4) in the wall (5) of the screw tube (1), the teeth (8,37. moving in the longitudinal slot (4) ) of the guide element (9) cleaning elements to keep the outlet clear.

2. Screw press according to claim 1, characterized in that an extension part (18) adjoins the screw tube (1) beyond the mouthpiece (3) and is formed by at least two radially expandable wall parts (21) which are formed by longitudinal slots (29). are separated from each other.

3. Screw press according to claim 2, characterized in that the extension part (18) against the pressing direction (A) is spring-loaded and displaceable along outer guide parts, the expandable wall parts (21) on a on one mouthpiece (3) displaceable carriage (49) are articulated radially movable.

4. Screw press according to claim 3, characterized in that fixed rolling bearings (52) are provided as guide parts, on which flat guide surfaces (44, 45) of the displaceable extension part (18) roll.

5. Screw press according to one of claims 1 to 4, with a pressure surface which can be placed on the end of the strand and which can be displaced in the pressing direction, characterized in that the screw press has a device (75) for canceling the counterpressure when the outlet length of the strand (10) corresponds to the length of the strand piece (72) to be cut off, has a cutting device (76) which can be inserted essentially perpendicular to the strand (10) after the counterpressure has been released, and a return device (77) for the pressure surface (74) into the starting position.

6. Screw press according to claim 5, characterized in that the pressure surface (74) is formed on a connecting web (102) which extends over approximately half the circumference of two disks (101) which are combined to form a roller (100) and which are eccentric on one Drive shaft are fixed, and the distance between them is greater than the cross section of the emerging strand (10).

7. Screw press according to one of claims 1 to 5, characterized in that the slope of the screw flights (7) in the region of the hopper (2) is increased, wherein a near-snail edge (19) of the hopper (2) is designed as a shear or cutting element is.

8. Screw press according to one of claims 1 to 5, characterized in that the feed hopper (2) is designed as a housing of a comminution device (149) in which a pair of counter-rotating rollers (150) from a plurality of interlocking and with fangs (145) equipped disks (144) is arranged, a grating (147) or the like below the comminution rollers (150). The total passage area can be adapted to the absorption capacity of the screw (6) by at least one movable cover (151).

9. Screw press according to claim 8, characterized in that the distances of the crushing rollers (150) to the grid (147) substantially correspond to the inside width of the grid openings and to the side walls (146) of the hopper (2) larger than the inside width of the grid openings are.

10. Screw press according to claim 8, characterized in that two covers (151) are arranged symmetrically parallel to the grid (147), the release of the total passage cross-section preferably by the movement of the carriage (49) of the expandable wall parts (21) of the extension part (18) is controlled.

11. Screw press according to claim 1, in which the guide element is formed by at least one toothed disk driven by the screw, characterized in that the toothed disk (11) with at least two successive teeth (8) at the same time snugly into the screw (6) engages, which tapers concavely in the engagement area corresponding to the circumferential line of the disc (11).

12. Screw press according to claim 1 or 10, characterized in that the guide element (9) extends over the last screw gear (7) in the mouthpiece (3).

13. Screw press according to claim 11 or 12, characterized in that the screw (6) at the level of the axis (42) of the driven disc (11) ends, and the disc (11) on the screw (6) by half the diameter in the mouthpiece (3) protrudes.

14. Screw press according to claim 1, characterized in that the guide element (9) by at least one with teeth (8,37) equipped, to the screw axis (12) towards the bar (14,36) is formed, which is in the plane of the longitudinal slot (4) is arranged to be radially movable, the length of each tooth (8,37) preferably corresponding to a maximum of half the distance between the associated pair of worm threads (7).

15. Screw press according to claim 14, characterized in that at least one pair of teeth (8) equipped strips (14) in diametrically opposed longitudinal slots (4) is arranged and radially movably coupled in the same direction.

16. Screw press according to claim 14 or 15, characterized in that the bar (14, 36) or the pair of bars (14) is connected on at least one side to a ring (16) surrounding the screw tube (1) at a distance, which is preferably guided parallel to the level of the bar (s) (14.36).

17. Screw press according to one of claims 14 to 16, characterized in that each strip (14.36) is positively guided by an eccentrically rotating element (15), the speeds of the eccentric element (15) and the screw (6) being the same .

18. Screw press according to claim 16 and 17, characterized in that the ring (16) is mounted on a roller bearing (7) on dan eccentric element (15) which is arranged coaxially with the screw axis (12).

19. Screw press according to claim 17 cder 18, characterized in that the eccentric element (15) on anan from dan screw tube (1) projecting support ring (32) is formed, which with the screw (6) via a reinforced section forming a spoke (33) of the worm gear (7) is connected.

20. Screw press according to claim 19, characterized in that on both sides of the support ring (32) an annular gap (40) as v / eiterer

Liquid leakage is formed.

21. Screw press according to claim 1 or 20, characterized in that the part of the guide element (9) which moves in the region of the longitudinal slot (4) or the region of the support ring (32) associated with the annular gap (40) with sharp-edged projections, elevations, Cutting (38.39) cd. is provided.

22. Screw press according to einan of claims 14 to 17, characterized in that each with the teeth (8) equipped bar (14) on one side on the screw tube (1) and guided radially displaceably on the other side, the strip joint ( 28) is displaced outwards in the axial direction via the end section (20) of the screw (6).

23. Screw press according to claim 3, characterized in that the expandable wall parts (21) are half-shells.

24. Screw press according to claim 3, characterized in that six or eight expandable wall parts (21) in the form of planes

Stripes are provided that complement each other to form a hexagon or octagon.

25. Screw press according to claim 3 or 4, characterized in that the guide surfaces (44, 45) on the outlet opening side di.

26. Screw press according to claim 25, characterized in that two rings (61) spaced apart from one another in the pressing direction (A)

Guide surfaces (44, 45) are provided, wherein the divergence of the guide surfaces (44) on the access opening side is greater than that of the guide surfaces (45) on the screw tube side.

27. Screw press according to claim 26, characterized in that the guide surfaces (44, 45) enclose an angle of 5 ° or 1 ° to the pressing direction (A).

28. Screw press according to claim 26, characterized in that each at least on the outlet opening side ring (61)

The guide surface (44) is delimited in the longitudinal direction by projections (54, 56) on both sides, of which the projections (54) on the screw tube side form end stops in the pressing direction (A) and the projections (56) on the outlet opening form a flange on which a compression spring (59) supports.

29. Screw press according to claim 28, characterized in that the compression spring (59) is supported on a pressure plate (58), and a roller bearing (57) is arranged between each projection (56) and the pressure plate (58).

30- screw press according to claim 5, characterized in that the pressure surface (74) which can be placed on the end of the strand (10) is formed on a piston (81) acted upon by the return device (77) counter to the feed direction.

31. Screw press according to claim 30, characterized in that the return device (77) is designed as a compression spring (59) which surrounds the piston rod (82) and is supported on an adjustable abutment (63) of the frame (60).

32. Screw press according to claim 3, characterized in that the expandable wall parts (21) are locked during the press feed of the emerging strand (10) and are opened during the ejection of the strand piece (72).

33. Screw press according to claim 5, characterized in that the cutting device (76) and the device (75) for canceling the counter pressure at the two ends of an ejection plate (94) are arranged, which in a longitudinal slot (88) of the extension part (18th ) can be inserted, with a cutting plate (93) oriented perpendicular to the strand (10) on the mouthpiece side and a displacement slide (95) with a run-up surface (97) on the pressure surface side, which is used to lift the pressure surface (74) from the end face of the strand (10) causes.

34. Screw press according to claim 6, characterized in that the drive shaft consists of two pins (103), each of which protrudes from the outside of a disc (101) and is rotatably mounted in a carriage (119) which in one

The sliding guide (104) is slidable in the pressing direction against a pressure element (105).

35. Screw press according to claim 6, characterized in that one end of the connecting web (102) of the rotatable roller is formed into a cutting edge (121) which forms the cutting device (76), and the other end of the connecting web (102) the device (75) forms to cancel the back pressure.

36. Screw press according to claim 6 and 23, characterized in that the movement of the expandable half-shells (108) is controlled by the roller (100).

37. Screw press according to claim 36, characterized in that on the periphery of the outside of each disc (101) is provided a recess (113) which extends approximately over half the base, which is offset by 180 from the connecting web (102), the half-shells (108) are assigned positive guide rollers (111) which roll on the peripheral region of each disc (101) facing the recess (113).

38. Screw press according to claim 37, characterized in that the two positive guide rollers (111) are arranged on parallel to the half-shells (108) extending guide elements (109) which are articulated on the end of the slide (49) of the extension part (18), whereby each guide element (109) is connected in an articulated manner to the roller-side end of the opposite half-shell (108).

39. Screw press according to claim 37, characterized in that a roller (112) is arranged on the outside of each half-shell (108) at the roller-side end, which rolls on the end face of a disk (101) of the roller (100).

40. Screw press according to claim 3, 23 and 38, characterized in that the articulated connections between the half-shells (108), the guide elements (109) and the slide (49) are each formed by bolts (110, 114) inserted laterally with play, whereby at least one contact surface of each articulated connection is curved.

41. Screw press according to claim 6 or 34, characterized in that a control disk (106) is arranged on the drive shaft, which has a switching cam (117) extending over half the circumference, which interacts with the drive of the roller (100).

42. Screw press according to claim 41, characterized in that the switching cam (117) actuates at least one limit switch (118) of the drive motor of the roller (100).

43. Screw press according to claim 41, characterized in that the switching cam (117) acts on a switching lever (122) which mechanically engages the roller drive.

44. Screw press according to claim 41 and 43, characterized in that the roller drive is a worm wheel (123) fixed on the roller drive shaft, a screw driving this (124), an axially displaceable intermediate shaft (125) extending the screw drive shaft (126), and one of motor of the press screw (6) rotated output shaft (135), wherein between the worm drive shaft (126) and the intermediate shaft (125) an axially displaceable toothed coupling (133) with a limiting stop (136) lying in the pressing direction and between the

Intermediate shaft (125) and the output shaft (135) of the press worm motor a friction clutch (129) is provided when the intermediate shaft (125) is moved in the pressing direction, and the cam-operated shift lever (122) axially displaces the intermediate shaft (125).

45. Screw press according to claim 44, characterized in that the friction clutch (129) is formed by axially offset conical disks (127, 128).

46. Screw press according to claim 10, characterized in that the grid (147) and the covers (151) are perforated

Sheets are formed.

47. Screw press according to claim 10, characterized in that the grid (147) from extending in one direction

There are rods (154), and sheets (151) are provided which have teeth (155) which extend along their contact edges over a plurality of rods (154) and which engage in one another in the closed position.

48. Screw press according to Anspiruch 2, characterized in that the expandable wall parts (21) on the mouthpiece side have outwardly angled, pivotably mounted legs and are acted upon by radial compression springs.