Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B30—PRESSES
  • B30B—PRESSES IN GENERAL
  • B30B11/00—Presses specially adapted for forming shaped articles from material in particulate or plastic state, e.g. briquetting presses, tabletting presses
  • B30B11/22—Extrusion presses; Dies therefor
  • B30B11/24—Extrusion presses; Dies therefor using screws or worms
  • B30B11/243—Extrusion presses; Dies therefor using screws or worms using two or more screws working in the same chamber
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
  • B27N—MANUFACTURE BY DRY PROCESSES OF ARTICLES, WITH OR WITHOUT ORGANIC BINDING AGENTS, MADE FROM PARTICLES OR FIBRES CONSISTING OF WOOD OR OTHER LIGNOCELLULOSIC OR LIKE ORGANIC MATERIAL
  • B27N3/00—Manufacture of substantially flat articles, e.g. boards, from particles or fibres
  • B27N3/08—Moulding or pressing
  • B27N3/28—Moulding or pressing characterised by using extrusion presses
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B30—PRESSES
  • B30B—PRESSES IN GENERAL
  • B30B11/00—Presses specially adapted for forming shaped articles from material in particulate or plastic state, e.g. briquetting presses, tabletting presses
  • B30B11/22—Extrusion presses; Dies therefor
  • B30B11/224—Extrusion chambers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B30—PRESSES
  • B30B—PRESSES IN GENERAL
  • B30B5/00—Presses characterised by the use of pressing means other than those mentioned in the preceding groups
  • B30B5/04—Presses characterised by the use of pressing means other than those mentioned in the preceding groups wherein the pressing means is in the form of an endless band
  • B30B5/06—Presses characterised by the use of pressing means other than those mentioned in the preceding groups wherein the pressing means is in the form of an endless band co-operating with another endless band

Definitions

• the invention relates to an extruder for small vegetable components mixed with binders to form compact strands for the production of pallet blocks, strips, profiles or the like with an arrangement for shaping, compressing and conveying the strand and with an arrangement for introducing thermal energy for the purpose of binding the binder.
• AI grit mats are formed from glued or unglued grit, preheating is first carried out with an air-conditioned fluid from air and water vapor which flows through the grit. Condensation of the water vapor in the spreading material is accepted. Thereupon, the spreading material mat which has been pretreated in this way is shaped in a continuous press or in a cycle press by hot pressing to form the final chipboard.
• Such technology is unsuitable for the formation of compact strands, especially when it comes to forming the strands with the help of an extrusion press and at the end of curing the individual benefits, e.g. B. by sawing off.
• the extrusion is first formed in a cold piston extrusion press, calibrated and pressed through a heated curing channel.
• the length of this extrusion press is depends on the cross-section of the strand and requires an extraordinary amount of space.
• the performance of such an extrusion press is limited due to the low thermal conductivity of the material.
• EP 0 376 175 B1 proposes to transport the batch compacted in an extrusion press through a reactor connected to the extrusion press by bringing the edge zone of the extrusion to a higher moisture level by means of water, water vapor or additional liquid or vaporous binder.
• these processes are only about changing the surface structure of the strand.
• the invention is based on the object of developing a continuously working extrusion press for the production of compact extrudates which works much more simply than the previously known piston extrusion presses, both in terms of construction and in terms of space.
• the solution to this problem according to the invention is that the arrangement for shaping and conveying the strand consists of endlessly rotating conveyors, in particular shaped-jaw conveyors, in the inlet gusset, the arrangement for introducing the thermal energy being provided.
• These conveyors which are preferably designed as shaped jaw conveyors, are intended to encompass the strand from all sides over its entire circumference. They serve to form and maintain the strand shape, as well as to apply the press energy.
• the surfaces of the conveyors facing the strand, in particular of the pairs of shaped jaws, are intended according to the invention to form a smooth and uninterrupted shape-maintaining surface, at least in the conveying area, so that the outer contour of the strand being formed is produced in a flat and smooth manner.
• the supply of thermal energy takes place primarily by introducing steam into the loose batch of small parts in a conveying area before or during shaping; b) the heat energy flow is directed into the inner region of the small parts mixture such that a
• the binding of the strand takes place when saturated steam is used by its condensation; d) the shaped strand passes through a heated shape-maintaining guide while avoiding additional pressing or thermal energy.
• a new method can thus be carried out, according to which essentially steam is primarily introduced as a heat energy source into the small part mixture before it is formed into a strand.
• the heat energy introduced must be so great that the condensation of the steam alone leads to the binding of the binding agent and thus hardening of the strand.
• the invention teaches to direct the steam into the interior of the mixture of small parts in such a way that a flow through the mixture of small parts predominantly takes place from the inside to the outside.
• the strand that has been formed and is already hardening only needs to be guided in a low-friction, shape-maintaining manner until the setting is completed.
• the guide means required for this should be warmed up so that no heat losses occur. However, it is not intended to introduce additional curing energy into the strand in the area of this guide.
• the principle of operation of the invention thus consists in immediately starting the reaction of the binder by the introduced steam, so that a relatively short clamping distance of the strand is sufficient to bring about the setting.
• the steam introduced into the loosely poured mixture of small parts should largely condense there so that a build-up of pressure in the subsequently compressed but not yet fully cured product strand is avoided.
• Molded-jaw conveyors rotating around the chain are particularly suitable as conveyors. In their place, however, circumferential steel strips or other equivalent effects Conveyors with appropriate stability and tear resistance can be used.
• the inlet area of the conveyors is formed by wedge-shaped, gently approaching runs, the wedge angle of which is a measure of the compression of the small batch.
• the wedge angle of 3: 1 has proven to be expedient, but this wedge angle should expediently be adjustable in order to change the compaction of the small part mixture as desired.
• the other conveyors acting on the sides of the strand form a shaft in the inlet area, the height of which is adapted to the wedge angle.
• Several conveyors forming the shaft are arranged on the same level one above the other.
• a middle conveyor has the width corresponding to the height of the side surface of the strand to be formed and runs along the entire conveyor line. The conveyors adjoining them upwards or downwards only cover the gusset on the side and are only one length in length until the strand is completely enclosed by the conveyors.
• the invention also relates to an arrangement with which the controlled feeding of the small batch into the feed area of the conveyor can be ensured.
• the exemplary embodiment provides that at least one conveying aid for the batch of small parts extending parallel or slightly obliquely to the strand axis is arranged in the inlet region of the arrangement for shaping and conveying the strand.
• This conveying aid can consist, for example, of rotating screw conveyors. If the conveying aids are hollow, the thermal energy, in particular the steam, can be fed through them and directed into the interior of the small parts batch. Because of the tapered shape of the
• a conveying aid is formed in the ⁇ trang axis as a rotating conveying mandrel, which, however, must not be open at the front, because otherwise the thermal energy, primarily steam, introduced into the conveying mandrel could escape through the strand channel formed.
• the conveyor in the inlet region and along the "conveyor section are supported by heated pressure rollers which are mounted in heated pressure retainer rail. It is achieved thereby that along the conveying route can be no cooling of the strand, and that accordingly, the condensation of the steam in the Strand can take place unhindered.
• a pair of pressure rollers is arranged according to the invention, the distance between which is decisive for the maximum height of the strand. If you do that
• This contact pressure which can be determined, for example, by a load cell, can be used as a control means in order to change the speed of the conveying aids which are located in the inlet area of the arrangement. In this way the constancy of density of the strand generated.
• An independent object of the invention relates to the spatial shape of the mold jaws or the mold jaw conveyor.
• the mutually facing end edges of the pairs of mold jaws are interlockingly cylindrical and convex and concave and are centered on the curvatures, such that an uninterrupted shape retention surface is maintained even with mold jaws angled slightly to one another.
• the invention provides that the individual mold jaw is composed of several parts, according to which a central part has the convex and concave shape on its front edges, the central part being connected along its lateral edges with webs which are connected to one Grip the front edge of the adjacent central part in a fork shape and form the limb joint.
• Such webs are also preferably used to produce bevelled edges on the strand, as are required for pallet blocks.
• the webs therefore encompass the shape-forming surface of the central part and have the required bevels in the overlapping part.
• the webs are also concave or convex at the end so that no changes in shape of the bevelled edge surfaces of the strand occur at these points.
• FIG. 1 a schematic partial side view of a continuous extrusion press
• FIGS. 2 and 3 partial side views of the inlet area of the extrusion press according to FIG. 1 in different types of embodiment
• FIG. 4 a cross section through the conveyor section of the extrusion press along the line IV-IV with one surrounded by pairs of shaped jaws
• Figure 5 a vertical section through the
• Figures 6 to 8 side view, top view and cross section
• the front part of an extrusion press (1) for forming a compact strand (2) is shown in side view, which has an arrangement (3) for shaping and compressing the strand (2), an arrangement (4) for conveying the Contains strands (2) and an arrangement (5) for introducing thermal energy primarily in the form of steam in a loose batch of small parts (7). It is assumed that the mixture of small parts (7), which is mixed with binders and consists of small plant parts, ' is shaped by a feed channel (6) of any shape into the inlet gusset (8) of the arrangement (3).
• the arrangement for shaping, compressing and conveying the strand (2) in the exemplary embodiment consists of rotating mold jaw conveyors (12, 13, 14).
• the mold jaw conveyors (12, 13) delimiting the strand at the top and bottom are guided circumferentially over deflection rollers (16) and form a wedge in the inlet gusset (8), the wedge angle of which is decisive for the size of the compression of the loose mixture of small parts (7).
• the runs (23, 24) of the upper and lower mold jaw conveyors (12, 13) come into the range of action of a pair of pressure rollers (17), the distance between which is responsible for how thick or high the strand (2 ) is in its final form.
• the invention therefore differs from the prior art in that the thermal energy required to set the binder is introduced into the loose small batch (7) before it is shaped and compressed.
• the loose mixture of small parts made of small plant parts that is pressed is a so-called non-rising mixture. Accordingly, it can be expected that the batch of small parts located in the inlet gusset (8) will be carried along by the sloping runs (23, 24) of the mold jaw conveyors (12, 13) and compressed accordingly.
• the invention proposes to provide additional conveying aids in the inlet area of the extruder (1), for example in the form of one or more screw conveyors (9), which have the task of targeting the small parts batch (7) located in the feed channel (6) To promote the inlet gusset (8) of the runs (23, 24). It is advisable to make these • conveying aids (9) hollow, to provide them with holes in the wall and thereby to introduce the thermal energy or steam into the interior of the loose mixture of small parts (7). Of course, the binding does not rule out the introduction of the steam into the small parts mixture (7) through other central lines. With (11) the steam outlet holes in the conveying aids (9) are shown.
• the conveying aids taper conically in the conveying direction in order to bring about an even supply of the small part quantity (7).
• a variant is shown in such a way that a plurality of conveying aids (9), for example in the form of screw conveyors, are partially arranged at an angle in the inlet gusset (8), the conveying direction of which is aimed specifically at the point between the pair of pressure rollers (17).
• one of the pressure rollers (17) is equipped with a load cell (20), which measures the spreading pressure which the small parts mixture (7) exerts when it passes the pressure roller pair (17).
• this pressure measuring device (20) can be used to change the delivery rate of the small batch (7), which can be done, for example, by changing the speed of the delivery aids (9). In this way, a dependent function between the pressure of the pressure roller pair (17) and the delivery rate of
• This rotating conveying mandrel forms a strand channel (21) in the strand (2), as is useful, for example, for the production of pallet blocks.
• This rotating conveyor mandrel (22) can also be hollow and charged with steam. However, the conveying mandrel (22) must be closed at the end in order to prevent the steam from escaping through the strand channel (21).
• a cross section along the line IV-IV in FIG. 1 is shown through the strand (2), which is encompassed by pairs of shaped jaws (25, 26) over its entire circumference.
• This strand (2) is a compact strand, which is used in particular for the production of pallet blocks. Accordingly, the longitudinal edges of the strand (2) are provided with bevels (39).
• the upper and lower pair of mold jaws (25) is consequently designed such that it produces this bevel (39).
• the lateral mold jaw pairs (26), on the other hand, are simply prismatic in cross section and determine the side surfaces of the strand (2).
• the inner surfaces of the pairs of mold jaws (25, 26) are designed as shape retention surfaces (27) and are designed so that they form a flat and uninterrupted surface as the strand passes through the conveyor section (4) in order to avoid irregularities in the shell of the strand (2 ) to avoid.
• Pressure rollers (18) which are mounted in pressure holding rails (19), engage the outer surfaces of the pairs of mold jaws (25, 26). Both the pressure rollers (18) and the pressure holding rails (19) are heated and prevent the heat from the strand (2) from flowing away.
• Form die pairs (26) assume their position shown in FIG. 4 right from the start.
• the spatial assignment is shown in Figure 5, which shows a cross section along the line VV in Figure 1.
• the cross section of the strand (2) is shown here in symbolic dash-dotted lines.
• the upper and lower mold jaws (25) are still at a distance from this.
• a shaft (28) is formed in the area of the inlet gusset (8) from the lateral pairs of mold jaws (26) and the additional lateral guide conveyors (30) adjoining them on both sides, which prevents the batch of small parts located between the runs (23, 24) from moving sideways can.
• These lateral guide conveyors (26, 30) are guided via common vertical deflecting rollers (29).
• the length of the lateral mold jaw conveyor (14, 26) is guided over the entire distance of the extrusion press (1), whereas the adjoining lateral guide conveyor (30) only have a length up to the end of the gusset (8).
• the dimensions are shown in dash-dot lines in FIG.
• the spatial shape of the chain-like interlocking jaws (25, 26) shown in FIGS. 6 to 8 disclose an independent subject of the application of the application.
• the mutually facing end edges (32, 33) of the pairs of mold jaws (25, 26) are cylindrical and convex and concave, and are centered on the curvatures, such that even with slightly angled mold jaws (25) there is an uninterrupted shape retention surface ( 27) is maintained. If the mold jaws (25, 26) are designed so that they can also produce the bevels (39) of the strand (2), then the
• FIGS. 6 to 8 it is disclosed in FIGS. 6 to 8 that the individual shaping jaw (25, 26) is formed in several parts.
• a central part (31) is connected at its lateral edges (36) with webs (37) which project beyond the shape-maintaining surface (27). In this way it is possible to impart the concave or convex edge shape (32, 33) to the front of the middle part (31).
• the lateral webs (37) are arranged on a front side to form a fork (38).
• This fork (38) projects beyond the concave frontal edge (33) of the central part (31) and encompasses the convex edge (32) of the adjacent central part (31).
• the edges of the webs (37) are also convex and concave to fit into one another, because it must be ensured that the bevels (39) (cf. FIG. 4) of the strand (2) must be continuously reproduced.
• the webs (37) and the middle part (31) are connected to one another in a conventional manner, for example pinned or screwed.
• the drive of the shaped jaw conveyors (12, 13, 14, 15) can be designed in the usual way, for example in that the individual shaped jaws (25, 26) have rack-like profiles, into which suitable ones
• Extrusion press Forming arrangement Arrangement for conveying Arrangement for introducing heat energy Feed channel Loose small batches Inlet gusset Conveyor taper Steam outlet bore
• Upper mold jaw conveyor Lower mold jaw conveyor forehead shaping roller shaping roller pressure roller holding pressure roller holding pressure roller holding pressure roller holding pressure roller vertical deflection roller lateral guide conveyor middle section convex frontal edge concave frontal edge swivel joint bushing side edge web fork bevel of the strand

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Manufacturing & Machinery (AREA)
• Wood Science & Technology (AREA)
• Forests & Forestry (AREA)
• Dry Formation Of Fiberboard And The Like (AREA)
• Finger-Pressure Massage (AREA)
• Fodder In General (AREA)

Applications Claiming Priority (3)

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• 2000
  • 2000-03-09 DE DE20004452U patent/DE20004452U1/de not_active Expired - Lifetime
• 2001
  • 2001-03-01 WO PCT/EP2001/002293 patent/WO2001066339A1/fr active IP Right Grant
  • 2001-03-01 DE DE50100834T patent/DE50100834D1/de not_active Expired - Lifetime
  • 2001-03-01 EP EP01929380A patent/EP1261476B1/fr not_active Expired - Lifetime
  • 2001-03-01 AT AT01929380T patent/ATE252449T1/de active

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