EP0399214A1 - Device for drying of loose material, especially beet chips - Google Patents

Abstract

The invention relates to a device for the drying of bulk loose material, in particular beet chips, in a drying chamber (1), through which flows a drying medium, and which is provided with a perforated floor (2) as a deposition surface for the bulk loose material, and in which is arranged a device for moving the bulk loose material. It is the object of the present invention to create using simple means a device of the simplest possible construction for drying in particular beet chips, which functions reliably over long periods of operation. The invention comprises the perforated floor (2) being made of sieves and being fixed into the drying chamber (1), the device for moving the loose material bulk being composed of carriers (6), which move immediately above the sieve floor (2) and parallel to it, and the drying medium feed line (19) being arranged beneath the sieve floor (2) and the drying medium discharge (20) above the sieve floor (2). <IMAGE>

Description

The invention relates to a device for drying bulk material, in particular beet pulp, in a drying chamber through which a drying medium flows and provided with a perforated floor as a support surface for the bulk material, in which a movement device for the bulk material is arranged.

Such drying devices have become known in various embodiments. In the drying device of DE-GM 1 666 714, the annular perforated base is divided into a plurality of segments which can be tilted about radially arranged axes in order to be able to pass the bulk material from one perforated floor level to the next one underneath during drying. A similar embodiment is known from US-PS 17 69 491, in which the perforated bottom elements foldable below a spokes Spoked wheel are arranged, wherein the folding joints are arranged below the spokes. The spoked wheel, which consists of an inner and an outer ring, rotates around a vertical shaft together with the perforated bottom.

In the case of such dryers, the feeding and emptying of the individual perforated floor levels is often carried out with screw conveyors, as shown in US Pat. No. 864,186.

Such screw conveyors are also used in the drying device of DE-PS 33 37 945, in which several levels of rotating perforated plates are arranged around an axial shaft and combined to form a drying unit. Several such drying units are located one above the other in the same housing.

In practice, the rotating perforated plates have not proven themselves when drying beet pulp. On the one hand, the loading and emptying of these perforated plates by means of screw conveyors was not as easy as one had imagined; on the other hand, beet pulp settled between rotating parts that were only a relatively short distance apart, where they became a viscous paste made the movement of the rotating parts so heavy that motors were overloaded and the device had to be shut down again and again for cleaning, which led to undesired interruptions in operation led. The articulated attachment of the perforated plate segments also led to mechanical faults. As a result, such dryers could not prevail in operation, although they promised considerable advantages over the belt dryers used in the sugar factories, both in terms of space requirements and in terms of energy.

The belt dryers used in the sugar factories work with conveyor belts that are provided with a large number of holes lying close together. The beet pulp is placed on these conveyor belts. The drying medium used for drying, usually the hot release from the steam and heat generating combustion devices, is pushed downwards from above through the layer of the chips lying on the perforated belt, in order to simultaneously press the edges of the perforated conveyor belt against sealing strips on both sides of the Press conveyor belt strands so that dry medium cannot escape to the side of the conveyor belt strand. These dryers also have their problems: in areas between the holes, the material to be conveyed dries less well than in areas above the holes. The drying medium passed through the layer of beet pulp from above presses the beet pulp together, so that the resistance to the drying medium passing through the beet pulp increases. In a not inconsiderable amount Fibers from the beet pulp are discharged downwards through the holes in the conveyor belt from the flow of the beet pulp to be dried. The flow resistance makes long conveying paths necessary, although it is still advantageous if the conveying path is divided into several partial paths on different conveyor belts arranged one behind the other, so that the badly dried beet chips lying in the area between holes come to rest on the subsequent conveyor belt at locations where they are better dried.

The present invention avoids the disadvantages of the prior art. It is the object of the present invention to use simple means to create a device for drying, in particular beet pulp, which is constructed in a very simple and very uncomplicated manner and which works reliably over long operating times.

The invention consists in that the perforated bottom consists of sieves and is firmly installed in the drying chamber, that the movement device consists of drivers that are moved parallel to the sieve plate just above the sieve plate, and that the feed and the discharge plate above the sieve plate of the drying medium is arranged.

This device is very simple. Because it has a fixed sieve plate, which is firmly mounted in the drying chamber. Above the sieve plate there is a driver for the dry material, which guides the dry material over the surface of the sieve plate. Since the drying medium flows through the sieve bottom from below, the movement of the drying material is facilitated, at the same time the layer of the drying material is loosened by the supply of the drying medium from below, so that the drying material only offers little resistance to the drying medium. The use of sieves results in a very uniform supply of the drying medium, so that a considerably increased effectiveness compared to the prior art is achieved in a small installation space. Also, there is no longer any smearing of the motor-driven drivers due to the compressed beet pulp. It is thus achieved that the device runs smoothly over long operating times without the need for cleaning.

An embodiment of this device can be equipped with a vertical shaft as a motion drive. In this embodiment, it is expedient if one of two coaxially arranged rings, between which spokes are arranged and which have approximately the same radius as the inner and outer circumference of the sieve plate, is mounted on the vertical shaft when the lower edges of the coaxial rings and the spokes lie in one plane, if the spokes have a lower height than the rings and if a filling device in the form of a bunker is provided above the spoke wheel, the front wall of which (as seen in the direction of rotation of the spoke wheel) is shorter than the rear wall and if (as viewed in the direction of rotation of the spoke wheel) is behind this bunker a discharge opening is arranged in the sieve bottom, under which there is a bunker for receiving the dried material.

This device, which is distinguished by a very simple construction, has a fixed sieve plate which is fixedly mounted in the vessel forming the drying chamber. Above this ring-shaped sieve bottom there is a spoked wheel, the rings of which are higher than the spokes, so that the material to be dried is held between the two rings and does not get between the rings and the fixed walls, does not get into the motor drive, not the drive belt, Drive chains and other drive elements smeared. It is thus achieved that the device runs smoothly over long operating times and that cleaning is necessary. Since there is only a single rotating part, namely the spoked wheel, the structure is very straightforward and simple, the device can therefore be manufactured very inexpensively and is very reliable in operation.

It is useful if the rings are about twice as big high as the spokes are. This ensures that the spaces between the spokes are always sufficiently filled with material to be dried, that the material to be dried is moved sufficiently and that the material to be dried cannot get outside the area which is intended for this material.

This spoke wheel can be driven by a motor via the shaft. This ensures a very simple structure of the device.

Another possibility is that the outer ring is driven by a motor. A simple drive can also be designed in this way.

One way of executing this drive is for the outer ring to carry a gearwheel in which a pinion driven by the motor engages. Another possibility of execution is that the outer ring carries a pulley or a support ring for a belt or a chain, which is driven by the motor.

Since this device is very straightforward and easy to set up, it may be appropriate to design the vessel as a pressure vessel, in particular to design it as a steam barrel. Since drying with steam is much more intensive than drying with dry air, the container can be used for the same throughput per time be built much smaller.

It is advisable to provide screw conveyors for feeding and emptying the bunkers. These screw conveyors convey into the bunkers reliably and easily. The problems that occurred in the prior art when loading and emptying the rotating ring sieve trays do not occur here.

This device works particularly cleanly if the rings of the spoke wheel run on slide rings, preferably made of plastic. This ensures that beet pulp cannot escape from the path intended for them.

It is also advantageous if the loading bunker is provided with a height-adjustable flap in order to be able to adjust the layer height of the material to be dried to the desired values.

It is also advantageous if at least one of the two bunkers is arranged in the vessel. This saves installation space and this type of construction is particularly advantageous when steaming under pressure.

With this device, drying can be so intensive that it is expedient to arrange only a single sieve plate in the vessel. Is the drying medium through this sieve plate and on If the mass to be dried stored there has passed through, the drying medium is so loaded with moisture that further use of this moisture-laden drying medium on another floor is not practical.

To save space, it may be advisable to arrange several vessels one above the other in a tower shape.

The device for drying bulk material according to the invention can, however, also be designed differently: Another embodiment of this device consists in that the sieve bottom is at least essentially rectangular and the drivers, preferably of vertically placed plate shape, follow a movement path parallel to an edge of the rectangle, the drivers are preferably pulled by chains, one strand of which runs parallel to the sieve, and the drivers preferably run on running rails. While in the previously explained embodiment of the invention the beet pulp is moved in a circle, here the beet pulp runs over a number of straight paths. This results in a particularly even drying effect. Here, too, are the advantages of easier mobility of the beet pulp through the drying medium supplied from below, no beet pulp fibers falling through the sieve bottom, the good drying effect due to the loosened dry material, and therefore the low drying energy consumption and kinetic energy consumption, the long operating times between cleaning and the other benefits have been preserved.

Here, too, it is possible to arrange several drying chambers one above the other and to use one and the same drive, in that the two runs of an endless carrier belt are guided over two screen surfaces arranged one above the other.

It is advantageous if the loading device and / or the emptying device is a screw conveyor and / or a bunker with preferably an allocation device arranged at the lower end.

An embodiment has proven to be particularly advantageous in which the sieve bottom is formed from wire mesh or wire mesh, preferably a coarser one, on which a finer one is placed, the coarser one being preferably attached to a support structure made of vertical sheets and the finer one being fastened by lateral rails is, which are preferably the tracks for the driver. Here the coarser sieve takes on a supporting function for the finer sieve. By using a very fine-meshed sieve, a very even distribution of the flows of the drying medium is achieved.

It is also particularly advantageous to use heated dry air or superheated steam as the drying medium, since this results in dried beet pulp, the fiber material of which can be used for human nutrition.

• Fig. 1 einen Längsschnitt durch eine kreisförmig fördernde Vorrichtung,
• Fig. 2 eine Ansicht des Speichenrades von oben,
• Fig. 3 eine Ansicht der Siebplatte mit den Kunststoff­lagerringen,
• Fig. 4 einen Querschnitt durch die Vorrichtung,
• Fig. 5 eine Ansicht des Füllbunkers,
• Fig. 6 die Vorrichtung mit Riemenantrieb,
• Fig. 7 die Vorrichtung mit Zahnradantrieb,
• Fig. 8 einen Längsschnitt durch eine andere Vorrich­tung, deren Speichenrad am Ende einer nur oben gelagerten Welle angebracht ist,
• Fig. 9 einen Schnitt durch eine geradlinig fördern­de Vorrichtung,
• Fig. 10 eine Ansicht von oben auf die Unterlage für den Siebboden,
• Fig. 11 einen Schnitt durch das förderseitige Ende des Siebbodens,
• Fig. 12 einen Schnitt durch einen Auflagepunkt des Siebbodens auf der Unterkonstruktion,
• Fig. 13 einen Querschnitt durch die Vorrichtung der Figur 9,
• Fig. 14 einen Längsschnitt durch eine in zwei Etagen arbeitende Vorrichtung mit geradlinigen Vorschub der Rübenschnitzel,
• Fig. 15 einen Querschnitt durch diese Vorrichtung.

The essence of the invention is based on in the drawing schematically illustrated embodiments. Show it:

• 1 shows a longitudinal section through a circular conveying device,
• 2 is a view of the spoke wheel from above,
• 3 is a view of the screen plate with the plastic bearing rings,
• 4 shows a cross section through the device,
• 5 is a view of the hopper,
• 6 shows the device with belt drive,
• 7 shows the device with gear drive,
• 8 shows a longitudinal section through another device, the spoke wheel of which is attached to the end of a shaft mounted only at the top,
• 9 shows a section through a straight-line conveying device,
• 10 is a top view of the base for the sieve bottom,
• 11 shows a section through the end of the sieve bottom on the conveying side,
• 12 shows a section through a support point of the sieve bottom on the substructure,
• 13 shows a cross section through the device of FIG. 9,
• 14 shows a longitudinal section through a device working in two floors with a straight feed of the beet pulp,
• 15 shows a cross section through this device.

In the fixed pressure vessel 1 is approximately in the middle hori an annular sieve tray 2 is permanently installed. This sieve bottom has a vertical cylinder 3 on its inner edge, which is firmly connected to it. This cylinder 3 carries a disk 4 in the middle. The sieve plate 2, the cylinder 3 and the disk 4 form a partition within the pressure vessel 1, which is permeable only in the area of the sieve plate 2. Above the sieve bottom 2 there is a spoke wheel 6 which is fixedly connected to the shaft 7 or can be rotated about the axis 7 about the shaft 7 (or if this is fixed). This shaft 7 or axis 7 is installed vertically in the vessel 1. The spokes 8 of the spoke wheel 6 are firmly arranged between two rings 9, 10. The inner ring 9 is connected to the shaft 5 by means of a disk 11 or further spokes or is connected to a hub running on the axis 5. The rings 9, 10 of the spoke wheel 6 are higher than the spokes 8, preferably twice as high, the lower edges of the spokes 8 and the rings 9, 10 are expediently in a common plane. Below these rings 9, 10 are sliding rings 12 on which the rings 9, 10 rest.

This device is fed by means of a screw conveyor 13, which conveys the material to be dried into a bunker 14 located within the pressure vessel 1. This bunker is expediently built in the form of a box which is at least open at the bottom, the walls of which expediently have different heights. The wall under which the material to be dried runs from the bunker into the annular space of the spoked wheel is expediently shorter than the others Walls, the lower edge of this wall is always below the upper edge of the rings 9, 10 of the spoked wheel 6. A displaceable or pivotable flap 15 is expediently provided here, the lower edge of which limits the material flow upwards. With the help of this flap 15, the height of the goods placed in the spoke wheel 6 can be determined. The opposite wall of the bunker 14 is expediently pulled down to just above the spokes 8, in particular when the outlet opening 16 through which the dried material falls into the bunker 17 is arranged directly in front of this wall. At this point, this wall causes the dried material to fall into the discharge opening 16 and not be conveyed further by the spokes of the spoke wheel.

Below the discharge opening 16 is the bunker 17 for receiving the dried material, which is conveyed out of the pressure vessel 1 by the screw conveyor 18.

This pressure vessel expediently has an inlet 19 in the lower region and an outlet 20 for the drying medium in the upper region.

As shown in FIG. 1, the spoke wheel 6 can be driven via the shaft 5, which is driven by the motor 21. But it can also be done via a motor 22 which drives a pinion 23 which engages in a ring gear 24 which is attached to the outer ring 10. Another way of driving is the drive via a belt 25 which is driven by the motor 26 by means of the pulley 27 and wraps around the outer ring 10 and is held by an annular disk 28. Instead of the belt 25, a chain can also be used.

This device is primarily intended for continuous dry operation. However, it can also be used for discontinuous operation if a batch of material to be dried is stopped by means of the spoke wheel 6, then the inlet for the drying medium is opened, after which the material to be dried flows through until the desired degree of drying is reached and then the drying medium supply is switched off, whereupon the spoke wheel is put into operation again in order to drop the dried material through the discharge opening 16 into the bunker 17.

In the exemplary embodiment in FIG. 8, the spoke wheel 6 is arranged at the end of the shaft 5, 7, which projects into the vessel 1 from above. In this embodiment, the motor 22 is carried by brackets 29, which enclose the bearing 30 for the shaft 5, 7 between them. In this case, the vessel 1 is divided by a partition 31 which receives the annular sieve 2 and has the outlet opening 16.

Such vessels can be stacked on top of each other be constructed. In this case, it is expedient to provide a common shaft 5, 7 for all vessels or to accommodate the motor 22 in the interior of each vessel. In this case there is also the option of using belts or chains to drive each spoke wheel either individually or via a shaft common to all drives.

In the exemplary embodiment in FIGS. 9 to 15, a rectangular sieve plate 32 is installed in the drying chamber 33, which rests on a support frame 34, which is composed of webs 35, 36. On the sides of the sieve plate 32 there are rails 37 for drivers 38, which are carried along by chains 39 arranged on both sides. The drivers 38 consist of vertically placed plates, sheets or boards which are guided closely above the sieve bottom 32 and promote the beet pulp 40. The chains 39 are guided over steering wheels 41, one of which is motor-driven. Below the sieve plate 32 there is a supply chamber 42 for hot air or steam with an inlet connection 43, above the sieve plate 32 there is a discharge chamber 44 with an outlet connection 45 for the removal of the dry medium, hot air or steam which has passed through the layer of beet chips 40. The beet pulp is fed in via the feed hopper 46, which has an adjustable slide 47 at the lower end, which serves to adjust the height of the beet pulp 40 which is carried along. At the end of this sieve At the bottom 32 there is a trough 48 for receiving the dried beet pulp 40. In this trough there is a screw conveyor 49 for discharging the dried beet pulp 40.

11 and 12 show how the sieve bottom 32 is attached to the support frame 34, which consists of the webs 35, 36. On the webs 35, 36, a support screen 50 is stapled at the stitching points 51. A fine-meshed sieve 52 is placed on the coarser-meshed support sieve, which is latched onto the angular web 54 at the end of the conveyor track running over the sieve bottom 32 by means of a holder 53 and is tensioned at the end on the input side by a tensioning device 55. The fine-mesh upper sieve 52 is fixed on both sides by the running rails 37.

In the exemplary embodiment in FIGS. 14 and 15, the lower run 56 of the chains 39 dragging the carriers 38 running below the sieve plate 32 is arranged above a further sieve plate 57. Here, the beet pulp is conveyed from the feed bunker 46 over the upper run and falls into the intermediate bunker 58, from where it falls onto the lower sieve tray 57 and is conveyed in the direction of the discharge bunker 59 by means of the drivers 38. The inlet of the drying medium takes place through the feed chamber 60. After passing through the sieve plate 57, the drying medium arrives in an intermediate chamber 61 and after passing through the sieve plate 32 the exit chamber 62.

The structure of the device can also be such that a feed chamber and an outlet chamber are provided for each strand.

List of reference numerals:

• 1 pressure vessel
• 2 sieve plates
• 3 cylinders
• 4 disc
• 5 wave
• 6 spoke wheel
• 7 wave
• 8 spokes
• 9 inner ring
• 10 outer ring
• 11 disc
• 12 slide ring
• 13 screw conveyor
• 14 bunkers
• 15 flap
• 16 outlet opening
• 17 bunkers
• 18 screw conveyor
• 19 inlet
• 20 Let go
• 21 engine
• 22 engine
• 23 sprockets
• 24 ring gear
• 25 straps
• 26 engine
• 27 pulley
• 28 washer
• 29 console
• 30 bearings
• 31 partition
• 32 sieve plate
• 33 drying chamber
• 34 support frame
• 35 bridge
• 36 bridge
• 37 tracks
• 38 carriers
• 39 chains
• 40 beet pulp
• 41 deflection wheel
• 42 feed chamber
• 43 inlet connection
• 44 discharge chamber
• 45 outlet connection
• 46 feed bunkers
• 47 slider
• 48 tub
• 49 screw conveyor
• 50 support screen
• 51 stitching point
• 52 sieve
• 53 bracket
• 54 bridge
• 55 tensioning device
• 56 lower run
• 57 sieve plate
• 58 intermediate bunkers
• 59 discharge bunkers
• 60 feed chamber
• 61 intermediate chamber
• 62 outlet chamber

Claims (10)

1. Device for drying bulk material, in particular beet pulp,
in a drying chamber through which a drying medium flows and provided with a perforated base as a support for the bulk material, in which a movement device for the bulk material is arranged, characterized in that
that the perforated bottom consists of sieves (2, 52, 57) and is firmly installed in the drying chamber (33), that the movement device consists of drivers (8, 38) which are above the sieve bottom (2,32,57) parallel to this be moved
and that the supply chamber (52) for supplying the drying medium is arranged below the sieve plate (2, 32, 57) and the discharge chamber (44) for the discharge of the drying medium is arranged above the sieve plate (2, 32, 57). 2. Device according to claim 1, with a vertical shaft as a motion drive, characterized in that
that on the vertical shaft (5) one of two coaxially arranged rings (9,10), between which spokes (8) are arranged and which have approximately the same radius as the inner and outer circumference of the sieve plate (2), is mounted , that the lower edges of the coaxial rings (9, 10) and the spokes (8) lie approximately in one plane,
that the spokes (8) have a lower height than the rings (9, 10),
that a filling device in the form of a bunker (14) is provided above the spoke wheel (6), the front wall (viewed in the direction of rotation of the spoke wheel (6)) being shorter than the rear wall,
and that (seen in the direction of rotation of the spoke wheel) behind this bunker (14) a discharge opening (16) in the sieve bottom (2) is arranged, under which there is a bunker (17) for receiving the dried material. 3. Device according to claim 1 and 2, characterized in
that the shaft (5) is driven by a motor (21),
or that
the outer ring (10) is driven by a motor (22, 26), the outer ring (10) of the spoke wheel (6) preferably having a ring gear (24) into which a pinion (23) driven by the motor (22) intervenes,
or that the outer ring (10) of the spoke wheel (6) carries a pulley or a support ring (28) for a belt (25) or a chain which is driven by the motor (26). 4. Apparatus according to claim 1 and 2, characterized in
that the rings (9, 10) of the spoke wheel (6) are approximately twice as high as the spokes (8),
and or
that the rings (9, 10) of the spoke wheel (6) run on slide rings (12), preferably made of plastic. 5. The device according to claim 1, characterized in
that the vessel (1) is designed as a pressure vessel, in particular as a steam barrel. 6. The device according to claim 1, characterized in
that the loading bunker (14) is provided with a height-adjustable flap (15). 7. The device according to claim 1, characterized in that
that several drying chambers are arranged one above the other and have one and the same drive, in that the drive shaft extends through these drying chambers and several spoke wheels are fastened to it or several outer rings are assigned to the drive shaft or, in the case of a chain drive, each strand is assigned to a drying chamber. 8. The device according to claim 1, characterized in that
that the sieve bottom (57) is rectangular and the drivers preferably follow a movement path parallel to an edge of the rectangle, preferably in the form of a vertically positioned plate,
the drivers (38) are preferably pulled by chains (39), one strand of which runs parallel to the plane of the sieve plate (57), and the drivers (38) preferably run on running rails (37). 9. The device according to claim 1, characterized in
that the loading device (46) and / or the emptying device (59) is a screw conveyor (49) or a bunker with preferably an allocation device (47) arranged at the lower end. 10. The device according to claim 1, characterized in that
that the sieve bottom (32, 57) is formed from wire mesh or wire mesh,
preferably from a coarser one on which a finer one is placed,
the coarser one being preferably attached to a support structure (34) made of vertical sheets and the finer one being fixed by side rails, which are preferably the running rails (37) for the drivers (38).

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