DE3035877A1 - Squeeze drying etc. sugar beet in two stages - with second piston comprising port to connect first and second pressing chambers - Google Patents

Abstract

Prods. contg. liquids, esp. sliced sugar beet are squeeze-dried in a press comprising two chambers with two separately operating pistons. A first chamber is filled from the feed shaft, the feed shaft is then closed, and the first piston precompresses the material against the rear of the second piston, which at this stage obturates its opening. The second piston, which is of two-part construction, now opens the passage to permit the product to be forced by the continuing movement of the first piston, into the second pressing chamber beyond the second piston; in this stage the material is rolled over and re-layered. The second piston, after closing its opening, then advances, while the first piston retreats to its starting position. The pressure in the precompression chamber (1) can be accurately regulated and the squeeze-drying is virtually continuous.

Description

Method and device for

Dehydration of Liquid Containing Products The invention relates to a method and a device for dewatering products containing liquid, especially for dewatering sugar beet pulp, with a pre-compression in a pre-compression chamber through a first compression piston and with a post-compression in a Nachpreßkammer by a second plunger, with a lockable filling shaft opens into the pre-compression chamber and the discharge of the drained Product from the secondary compression chamber on the opposite of the second compression piston Page takes place.

Particularly in the dewatering of sugar beet pulp the task of achieving the highest possible degree of drying. With the previously known Process and devices after dewatering was always too high a residual moisture available. Too much heating energy would have to be used for the final drying of the beet pulp will.

For dewatering either piston presses or Screw presses used. Despite a strong pressure increase, you couldn't get over one certain degree of drainage come. In addition, the previous oil presses the disadvantage that they could only be used discontinuously.

For this reason, multi-stage pressing devices have already been used in successively arranged presses mostly screw presses proposed. Disadvantageous however, there is the high expenditure on equipment for this.

In DE-OS 28 09 764 a cider press has already been proposed, in which a pre-compression and a post-compression are carried out in one device However, the disadvantage with this must press is that the pressure in the Antechamber can only be adjusted imprecisely. Karin continues with this f'resse only in cycles work, as you always have to wait until the second piston (the post-press piston) is back in its original position.

The present invention is therefore based on the object of a method and an apparatus for performing the method for continuous dewatering of liquid-containing products of the type mentioned at the beginning which the pressing pressures, in particular the pressure in the torpreßkammer, can be precisely regulated and where kD can be continuously drained if necessary.

According to the invention, this object is achieved by the characterizing part of claim 1 mentioned features solved By the invention Process with the two plungers, the second plunger between the prepress chamber and the Nachpreßkammer is, can contain the dewatering of liquid Regulate products to a very large extent. Since the two plungers are independent are adjustable from each other and also the opening in the second plunger through which the pre-pressed product gets into the post-compression chamber, the compression pressures can can be set as required over a wide range. The feed rates can also of the two plungers are chosen so that there is continuous drainage results.

If the shut-off device closes off the pre-compression chamber, so can away without the pressing pressure in the feed chute evading with the pre-pressing to be started. After a certain preselected pressure, which may also be zero can, the opening in the second two plunger plunger by a corresponding Displacement or rotation of the two plunger parts to each other released, so that the product can be pushed into the post-compression chamber. If then this opening is closed again, can with the Nachpreßvorgang by the second plunger can be started while at the same time the first F'reßko.lL) cn can return to its original position.

At the end of the repressing, the second plunger is back in his Starting position reduced There is the possibility that, after previously the Prepress chamber has been filled again by releasing the opening of the feed chute is to move the two plungers against each other during the pre-pressing phase. This can while the opening is closed in the second plunger, or if necessary also happen when the opening is open, so that already during the return stroke of the second Plunger the post-compression chamber is filled. It is only necessary that the volumes of the post-press and pre-press chambers are matched to one another.

A very important advantage of this method according to the invention is that a very high drainage or a very low residual moisture of the product to be treated can be achieved. This is due, among other things, to that the drainage zone t due to the long routes of the product is very long, resulting in a correspondingly long exposure time to the to be drained Cells is given.

The product is also very important for the high degree of dewatering the transport from the pre-compression chamber into the post-compression chamber via the opening. Included there is namely a circulation and redeployment process, which previously due to Their location poorly drained product parts can now get to better locations.

With the method according to the invention, the most varied Dewater productc because, as already mentioned, to a very large extent to the can be adapted to the respective requirements. In addition to sugar beet pulp, e.g. also almost all kinds of fruits such as apples, olives and the like, brewer's grains, pulp suspensions other products and waste products e.g. B. dewatered sludge and juiced.

Especially for the dewatering of large sugar beet pulp it is of advantage if the re-pressing is essentially in an annular gap between the perforated cylinder jacket and one lying in the interior of the Nachpreßkqmmer perforated Packing body, the diameter of which increases towards the discharge @, takes place.

Such subsequent pressing allows the dryness content of the product to be dewatered to be increased even further. This is essentially due to the fact that the pressing fluid of each product part only has to cover short distances, because it can be discharged immediately either through the perforated filling body or through the perforated cylinder jacket. Because the annular gap is reduced towards the discharge, the product is squeezed out more and more. This means that re-moistening is excluded. Press room A device for carrying out the process in a / with a first plunger and a prepress chamber into which a lockable filling shaft opens, with a second plunger behind which a Nachpreßkammer is arranged, and with a discharge opening for the dehydrated product is that between the A filling shaft and the pre-compression chamber a Abspcrrvo rricl ung is arranged that the second, the first plunger opposite plunger is constructed in two parts and is provided with at least one passage opening to the downstream compression chamber.

Further features according to the invention emerge from the subclaims, which are dealt with in connection with the exemplary embodiment.

An exemplary embodiment of the invention is shown below in principle shown.

It shows: r L (l. 1: The side view of a press according to the invention; Fig. 2: an enlarged detail of the side view in a pressing position with opened second plunger; Fig. 3: a cross-section along the line III - III of Fig. 1; FIG. 4: enlarged detail X from FIG. 1; FIG. Fig. 5: Enlarged section Y from FIG. 1.

Good press has a pre-compression chamber 1, above which a Feed chute 2 is arranged. By means of a locking device e.g. slide 3, the hydraulic or is operated in another way, the pre-compression chamber can after appropriate filling getting closed. A first plunger is located on one side of the prepress chamber 4, while a second plunger 5 is arranged on the opposite side is. The second plunger is made in two parts and has an outer piston ring 6 and an inner piston part 7a. The outer piston ring is a star ring formed with ribs 8 extending approximately in the radial direction obliquely to the center. The inner piston part 7 has a truncated cone shape, with its conical surface Can create sealing on the inner peripheral wall of the outer piston ring 6. Of the outer piston ring 6 is on an outer piston-displaceable element in the axial direction 9 and the inner piston part 7 on a likewise displaceable in the axial direction inner piston rod 10 attached. The two rods 9 and 1O are independent can be moved from each other. The inner piston part 7 is also on the outer one Piston rod 9 out.

The plunger 4 and also the two-part plunger 5 rllit the lines that can be moved independently of one another are hydraulic actuated.

behind the second plunger 5 there is a post-press chamber 11, in which a perforated filling body 12 is arranged. The packing has in essentially a frustoconical shape, which, however, consists of several in a row arranged parts with conical or frustoconical shell sections 13 and cylindrical jacket sections 14 is composed. On the front is the conical shell part 13 of the filling body 12- surrounded by a bearing ring 15, of the ribs running obliquely to the center in a radial direction 16 is connected to the filling body 12. The ribs 16 cause a further circulation of the product.

together with the peripheral wall of the compression chamber 11 in this area the bearing ring 15 forms an Oleitlager, so that, with appropriate training, too of the rear bearing, the filling body 12 can be moved in the axial direction. In this way, the post-compression chamber 11 can be enlarged or reduced accordingly will.

Through the interior of the filler body 12 is one of a motor driven shaft 17 out, on the terrain of the Nachpreßkammer 11 protruding end a mixer in the form of a bar mixer 18 is arranged. did a joist mixer can of course also be another mixing device, e.g. a spindle or screw be used. If necessary, the shaft 17 can also be displaced in the axial direction be designed so that the mixing element 18 optionally further into the post-compression chamber 11 can be put in above.

The walls of the press are perforated and the discharge of the pressed Liquid takes place through outlets 19 and 20, while that through the perforation of the filling body 12 in the interior thereof liquid reached via an outlet line 21 is discharged.

Via an inlet line 22 and an annular channel 23 can be in the area of the second plunger 5 / if necessary a treatment liquid is initiated will. So 7.0. a liquid that promotes the dewatering of sugar beet pulp admitted. that causes a chemical reaction that solidifies the cell - * when this is essentially in the inserted state1 substance the sugar beet pulp and thus an improvement in the pressing process occurs. The addition in this area is particularly advantageous because that is to be dehydrated Product is somewhat relaxed for a short time when it enters the post-compression chamber 11.

The first plunger 4 has a sieve disc on its front side 24 provided. The arrangement of the sieve disk is shown in the enlarged detail of FIG. 4 24 clearly visible. On the back, the Sicb disk 24 has several spacer cams or strips 25, so that there is a collecting space for the squeezed out liquid, which can then be discharged via an outlet opening 26.

The dehydrated product is discharged; over an annular gap 27 at the end of the post-compression chamber 11.

By a retaining ring 28, the hydraulically in the axial direction on the Jacket of the filling body 12 can be moved knr> n, the size of the outlet opening to be set. The pressing pressure can also be determined in this way.

If necessary, however, an exit ring 28 can also be omitted.

It has been found, surprisingly, that by training of the packing with its al alternating frustoconical and cylindrical Jacket sections a very good extrusion is achieved. For example, it has been established that the cylinder-shaped sections 14 act as a kind of "plug" through which the pressure in the jacket section behind it is maintained. In this way the product will continue to dehydrate even if e.g. the second plunger 5 is withdrawn. By bridging between the individual product parts in the cylindrical shell sections 14, so that these act like a piston and the sections behind it act accordingly keep under pressure.

The dehydration of a product, e.g. sugar beet syrup, takes place in the following way: From the feed chute 2, the product arrives in the pre-compression chamber 1. When this is filled, it is opened by the gate valve 3 closed and then the first plunger 4 is moved (to the left in the drawing). Either the second plunger 5 can be arranged in this way be that by an abutment of the inner piston part 7 on the inner peripheral wall of the star ring 6 is given a tight seal and the two-part plunger 5 only opens at a certain, preselected operating pressure, or during the The two piston parts of the second are already the two piston parts of the second piston The plunger 5 moved apart, as shown above from the. 2 ersicilkl.ieh will. The separation of the two-part plunger 5 takes place in that the inner piston part 7 by a corresponding axial displacement of the inner piston rod 10 is shifted by a small amount (in the drawing to I. left). To this Way there is an opening for the product to be dewatered through which it is between the ribs 8 and the resulting annular gap between the inner piston part 7 and the star ring 6 the Nachpreßkammer 11 can get.

When the first plunger 4 has reached its end position, i. E. when he completes the pre-compression chamber 1 has passed through the passage through the second plunger 5 closed again by the inner Piston part 7 is pushed back again (to the right in the drawing) and sealing is applied to the outer piston ring.

Then the first plunger 4 moves back into its starting position back, while the second plunger, now as a closed unit, over the outer piston rod 9 is moved forwards (to the left as shown in the drawing), whereby a corresponding repressing of the product to be dewatered in the repressing chamber 11 takes place.

Since it occurs during the passage of the product through the second plunger 5 has come to an upheaval and rearrangement, can be in the post-compression chamber, in particular in the narrowing annular gap between the filling body 12 and the Circumferential wall can still achieve very good drainage. The overturning and redeployment During the passage, the ribs can be positioned accordingly 8 (e.g. inclination or twisting) can still be improved.

During the Naellpreßvorganges, if the Absverrscilieber 3 is withdrawn accordingly, the pre-compression chamber 1 will already be filled again.

Then the second plunger 5 is in its extended end position (shown in dashed lines), so can, if desired, already during of the return stroke of the second plunger 5 again with a pre-compression in the pre-compression chamber 1 can be started.

llierzu can, if necessary, the two plungers 4 and 5 with a corresponding Controls are moved towards each other *. It is also possible to start with Beginning of the return stroke of the second plunger 5, or at any other point of the return stroke to separate the two piston parts 6 and 7 again, so that already during of the return stroke of the second plunger 5, the product to be dewatered into the post-press chamber 11 arrives.

Characterized in that the two plungers 4 and 5 are independent of each other can be moved and at the same time the second plunger as a unit or can function as a two-part piston, all parts being independent of one another * Through this movement a continuous process is achieved, because always one Piston is in pressing function.

are movable, can be depending on the to be drained Product the press in different ways and at different pressures use optimally in relation to the product.

It goes without saying that it is also not unconditional within the scope of the invention required that the second plunger 5 formed in two parts in the form shown is only required that by a mutual shift or Twisting result in one or more openings through which the product to be dewatered from the pre-compression chamber 1 into the post-compression chamber 11. For example, a plunger can also be used used: which essentially consists of two disks one behind the other consists, which are provided with openings, whereby by a corresponding rotation of the two discs to each other either the openings are aligned with each other or are covered.

The jacket of the filling body 12 can either itself for good drainage be provided with a multitude of small holes, or what is even easier to manufacture is, it is provided with relatively large holes and over the jacket is a support fabric (Away- 29 stand cams, spacer bars or the like.) / Placed, with then over the supporting fabric or the like. a fine-mesh sieve 30 is stretched. In this way the supporting fabric underneath the fine-meshed sieve acts like a drainage and good drainage is achieved.

If necessary, the can when opening the second plunger 5 between the inner and outer piston parts 7 and 6 resulting annular gap adjustable be.

This allows the pressure in the pre-compression chamber 1 and the flow rate be managed.

Claims (23)

P a t e n t a n s p r ü c h e Process for dewatering liquid containing products, in particular for watering sugar beet pulp a pre-compression in a pre-compression chamber by a first compression piston and with a Re-pressing in a re-pressing chamber by a second plunger, with a lockable Filling shaft opens into the pre-compression chamber and the discharge of the dehydrated product from the Nachpreßkammer on the opposite of the second plunger Page takes place, that is, that after the shut-off of the Linfülischachtes (2) the pre-compression between the first and the second plunger (4, 5) takes place, after which the two-part second plunger (5) at least releases an opening and the product for re-pressing by the further feed of the first plunger (4) through the opening in the rear of the second plunger (5) lying post-compression chamber (11) with circulation and rearrangement of the product pushes out and the second plunger (5), after closing the opening, through his Feed carries out the post-pressing while at the same time de.r first plunger (4) returns to its original position. 2. The method according to claim 1, d a d u r c h g e k e n n z e i c h n e t that the re-pressing is essentially in an annular gap between the perforated Cylinder jacket and a perforated filler body located inside the post-press (12), the diameter of which increases towards the discharge, takes place. 3. Device for carrying out the method according to in a press housing, Claim 1 9der z with a first price cylinder and a prepress chamber into which a lockable filling shaft opens, with a second plunger, behind the one Nachpreßkammer is arranged, and with a discharge opening for the dehydrated Product, d u r g e k e n z e .1 c h n e t, that between the feed chute (2) and the pre-compression chamber (1) a shut-off device (3) is arranged that the second, the first plunger (4) overlying plunger (5) formed in two parts is and with at least one passage opening to the subsequent compression chamber (11) is provided. 4. Apparatus according to claim 3, d a d u r c h ge k k e n n z e i c h n e t that in the post-compression chamber (11) a substantially conical or frustoconical Filling body (12) is ordered, the diameter of which towards the discharge opening (27) increases. 5. Apparatus according to claim 4, d a d u r c h g e k e n n z e i c n e t, daO the filling body (12) between conical or frustoconical Has jacket sections (13) cylindrical jacket sections (14). G. Vorri.chtung according to claim 4 or 5, d u r c h e k e n n n show that the filling body (12) is perforated and has a drainage line (21) is provided in its interior for the squeezed out liquid. 7. Apparatus according to claim 3, 4 or 5 or 6, d a d u r c h g e it is not noted that the two-part second piston consists of one on one axially displaceable outer piston rod (9) arranged outer Piston ring (6) and an inner one which is also displaceable in the axial direction inner piston rod (10) arranged inner piston part (7), wherein the inner piston part (7) sealingly fit into the outer piston ring (6) and both Piston parts are mutually displaceable. 8. Apparatus according to claim 7, d a d u r c h g e k e n n z e i c n e t that the outer piston ring as a star ring (6) with approximately is formed in the radial direction obliquely to the center ribs (8). 9. Apparatus according to claim 7 or 8, d a d u r c h g c k e n n z e i c h n e t, the inner piston part (7) has a truncated cone shape, its Conical shell can be pressed against the inner circumferential wall of the outer piston ring (6) in a sealing manner is. 10. Device according to one of claims 3 to 9, d a d u r c h g It is not noted that the end wall directed towards the pre-compression chamber (1) of the first plunger (4) with a spaced from the end wall Sieve body (24) is provided and in the lower region of the plunger one of the gap between the strainer body and the end wall of the plunger outlet pipe (26) for squeezed out liquid. 11. The device according to claim 10, d a d u r c h g e k e n n z e i c h n e t that the sieve body as a sieve disc (24) with the front side of Plunger-directed spacer cams or spacer strips (25) is formed. 12. Device according to one of claims 3 to 11, d a d u r c h g e k e n n-z e i c h n e't that the outlet opening (27) for the dried product from the annular gap between the filling body (12) and the housing or cylinder wall is formed and a baffle ring (28) is arranged in front of the outlet opening itself. 13. The apparatus of claim 12, d a d u r c h g e k e n n z e i c h n e t that the retaining ring (28) is axially displaceable. 14. The apparatus of claim 13, d a d u r c h g e k e n n z e i c h n e -t that the retaining ring (28) is guided on the peripheral wall of the filling body (12) is. 15. Device according to one of claims 3 to 14, d a d u r c h g e k e n n n n n e i c h n e t that the filling body (12) is displaceable in the axial direction is. 16. Vorri.ch1: ung according to one of claims 3 to 15, d a d -u r c h g e k e n n n z e i c h n e t that through the interior of the filling body (12) a Shaft (17) is guided, at the front of which from the filling body (12) into the post-compression chamber (11) protruding end of a niche member (18) is arranged. 17. The device according to claim 16, d a d u r c h g e k e n n z e i c h n e t that the mixing element is designed as a rotating bar mixer (18). 18. The device according to claim 17, d a d u r c h g e k e n n z e i c h n e t? that the bar mixer (18) is displaceable in the axial direction. 19. Device according to one of claims 3 to 18, d a d u r c h g e k e n n n n z e i c h n e t that in the Nachpreßkammer (11) in the area of the second Preßkolhens (5) an inlet line (22, 23) for Bchandlungslösung opens. 20. Device according to one of claims 3 to 19, d a d u r c h g I do not know that the jacket of the filling body (12), which is provided with holes, is surrounded by a supporting fabric (29) over which a fine-mesh sieve (30) is stretched. 21. Device according to one of claims 3 - 20, d a d u r c h g e it is not possible to say that when the second plunger (5) is opened, the resulting The ring gap between the inner piston part (7) and the outer piston ring (6) is adjustable is. 22. The apparatus of claim 17 or 18, d a d u r c h g e k e n It is noted that the bar mixer (18) has a feed line for treatment liquid is connected and is provided with injection ports. 23. Device according to one of claims 3-22, d a d u r c h g e it is not indicated that the gate valve (3) is double-walled, where the inner wall directed towards the pre-compression chamber (1) for the discharge of pressing fluid is perforated.