NO139038B - EXTRUSES FOR PROCESSING VISCOSE MATERIALS AND THEN SPECIAL CAMP OR CLAY-LIKE MATERIALS - Google Patents

Description

The invention relates to an extruder for processing viscous materials, which extruder consists of a rotating transport member, which is arranged in a housing provided with an inlet and outlet opening, which transport member on its peripheral surface and distributed over its width exhibits several oriented in the direction of rotation and several of equal height projections, which along part of the rotation path practically reach the wall of the house,

and whereby a wiping device is arranged at the outlet opening which engages in the spaces between the projections.

An extruder of the initially mentioned type is known.

It has been a task of the present invention to further improve this known extruder. According to the invention, this is achieved by the protrusions in the middle area of the transport member having a greater distance between each other than in the outer areas.

By the fact that the protrusions of the transport member in the central area have a greater mutual distance than in the outer areas, a surprisingly even structure has been obtained in the pressed string.

Depending on the conditions, i.e. depending on the size of the string to be pressed and the material to be processed, it may be appropriate to let the distances between the protrusions successively decrease from the center of the conveyor towards the outer areas. The size of the distance change between the protrusions depends on the construction of the extruder as well as on the type of material to be processed. The distances between the protrusions in the central area of the transport

the body can e.g. be up to 2.5 times the distances between the protrusions in the outer areas. Preferably, the distance between the central protrusions is 1.5 times the distance between the protrusions in the outer regions.

The extruder is suitably constructed so that the protrusions,

which -are arranged on a carrier and separated from each other by

with the help of segment-shaped spacers, form projection segments. The spacers and the projection segments are suitably exchangeable and mutually interchangeable.

This makes it easy to exchange individual protrusion segments that are worn out. It is also easy to restore the transport device by changing the material to be processed. The segments are appropriately held together by means of a clamping device.

By arranging an additional rotating transport means, the extruder's capacity can be improved with a relatively small change in the size of the structure.

The transport member or transport members can be designed drum-like. With two transport means, these can be differently paired with each other. Preferably, however, uniform transport means are used, e.g. unite two faith-like ones with each other. Thereby, paired transport means can be guided to a common or to two different outlet openings. In the first-mentioned case, it is possible to dispense with wiping means for each individual transport means, whereby one transport means in turn acts as a wiping means for the other.

The wiping member or members are suitably designed comb-like with teeth extending between the protrusions. Optionally, however, the wiping bodies can also

be rotating and exhibit intervening protrusions in the spaces between the protrusions of the transport members.

Appropriately, the wiping device is adjustable or adjustable in its penetration depth between the protrusions.

Thereby, the wiping device not only allows itself to be adapted to certain materials to be transported, but the wiping device can especially also be adjusted when it becomes worn. It is furthermore particularly appropriate when the wiping device is composed of individual replaceable teeth or protrusions as well as spacers, which are held together with a clamping device.

This not only facilitates an exchange of worn teeth or protrusions, but also a replacement of the wiping member by changing the arrangement of the protrusions on the transport member.

The sides of the transport member are preferably sealed against the housing by means of a sealing device, and suitably have a labyrinth seal to prevent the material from escaping. This not only prevents the house from getting dirty, but also that the pressure can be kept at a certain height. In order to also prevent any passing material from entering the house, a device is preferably used to return the material coming out through the seal to the inlet opening.

It is also particularly advantageous to equip the house, which

located in a recess that accommodates the transport member, with a replaceable liner, so that in case of wear, only the liner can be replaced.

The quality of the string can be improved when, according to a preferred embodiment, a suction device is arranged for

evacuation of the inlet end of the extruder.

The string quality can also be improved with the help of a front-connected pre-press. This not only works by increasing the pressure, but also serves to mix the material. Particularly favorable results are achieved when the pre-press connected in front is of the same type as the main press.

When the conveyor occasionally needs to be expanded for maintenance or to rebuild the projection, it is recommended to equip the extruder with an extraction device for the conveyor.

The extruder is suitable for a wide variety of viscous materials, such as e.g. for pressing sludge, cellulose, pulp, and especially clay or clay-like materials.

In the following, the exemplary embodiment of the extruder according to the invention shall be described with the help of drawings.

Fig. 1 shows a two-stage extruder for clay materials i

partial longitudinal section.

Fig. 2 shows the extruder from fig. 1 in section 11-11 of fig. 1. Fig. 3 shows the main press, which forms the second stage, i

vertical longitudinal section and to a larger scale.

Fig. 4 shows the extraction device placed on the transport drum in a vertical longitudinal section, i

detail and on a larger scale.

Fig. 5 shows an extruder with two side-by-side transport drums with a stripping chamber in the rendering according to fig. 2. Fig. 6 shows an extruder with a transport drum and a stripping drum that engages with this ifclge

fig. 2.

Figures 1 and 2 show a two-stage extruder, which consists of a main press 1 and a pre-press 2 which are connected via a connection channel 3. Connection channel 3 is designed as a negative pressure chamber in the embodiment shown. The operation of the main press 1 takes place with the help of a drive mechanism 4, which is connected by means of a .remdrift 5, with a

drive motor. Analogously, the pre-press 2, which in the present example is a screw press, is also driven by means of a drive mechanism 6 and a belt drive 7.

The main press contains a housing 8 with a recess 9 for receiving a rotating transport member, which in the present example is designed as a transport drum 10, and whose housing contains both an inlet opening 11 and an outlet opening 12.

As can be seen in particular from fig. 3, the transport drum contains around its circumference several ring-shaped projections 13 distributed over the length of the transport drum and lying in the peripheral direction and practically extending to the wall of the house, which essentially have the same height. At the inlet opening 11 there is a rotating supply roller 14, which presses the supplied material into the spaces between the protrusions 13. At the outlet opening 12

a wiping device designed as a wiping comb 35 is arranged, which contains teeth that engage between the projections 13 and which takes over the material between the projections 13 in the transport drum 10.

The supply roller 14 has a cylindrical and smooth surface,

and it practically rests against the annular projections 13. The area on the conveyor roller 14 lying behind the transfer point between the conveyor roller 14 and transport drum 10 is coated by a wiper 17, which feeds the stripped material to the transport drum. Via an adjustment device 18, wiper 17 can be adjusted in relation to supply roller 14.

As can particularly be seen from Figures 1 and 3, the annular projections 13 a in the central area of transport drum 10 are arranged at a greater mutual distance than the projections 13 b in the peripheral area. The annular projections

13 a and 13 b are formed by means of the ring segments 19, which in the present case make up a quarter of the ring. These ring segments are arranged on a support cylinder 20 and are kept at a distance by means of spacer rings 21. The ring segments 19

and the spacer rings 21 are secured against distortion by means of the wedges 22 on the support cylinder 20. The ring segments 19, which form the protrusions 13, are held together with the spacer rings 21 by means of a tensioning device 23. The tensioning device in the present example consists of a tension rod that runs transversely through the ring segments and the spacer rings. The ring segments of the projections are easy to replace and mutually interchangeable.

The same also applies to the spacer rings.

In contrast to the embodiment shown, continuous rings can also be used instead of ring segments 19, and spacer ring segments can also be used instead of spacer rings. It would also be possible to form the protrusions 13 a and 13 b by creating annular grooves in a cylinder.

The sides of the transport drum are sealed against the housing by means of a sealing device 25. The sealing device is preferably designed as a labyrinth seal, and exhibits an annular groove 26 in which an annular flange 27 belonging to the housing intervenes. On the outside, this annular groove 26 is joined by a further annular groove 28 into which existing material enters, which material passes through the annular groove 26 protected by the annular flange 27. In the outer annular groove 28, a return device 29 engages, which reduces what has penetrated into the outer annular groove 28 and present material by means of a scraper 30, which material is returned through an opening 31 to the inlet opening of the main press.

The recess 9 in the housing 8 is provided with a wear-resistant and replaceable lining 32, which protects the housing against wear.

The wiping comb 15 consists of individual teeth 16, which are held by means of spacers at a distance corresponding to the respective thicknesses of the protrusions 13. The individual teeth 16 are replaceable in order to be replaced in case of wear. The teeth and the spacers are held together by means of a clamping device 33 which is designed as a tension rod in the same way as the clamping device 23 for the protrusions of the transport drum. The ironing comb is preferably arranged in such a way that its penetration depth between the protrusions 13 is settable or adjustable. Thereby, in case of wear, the wiping comb can be adjusted within certain limits.

The outlet opening 12 is formed by a housing part 34 which is separated from the rest of the housing 8, and which can be opened and removed. After opening this housing part 34, the wiping comb 15 is accessible. The housing part 34 can also be exchanged for parts that have other cross-sectional openings.

As can be seen in particular from fig. 3, the house has a house plate

35 which covers one front side of the recess 9 for the transport drum 10. The housing plate carries the one bearing 36 to the shaft 37

on which the transport drum 10 is arranged. The housing plate 35 is removable, whereby at the same time the bearing 36 is pulled from the shaft 37

while completely exposing the transport drum 10, and so that this can be pulled off the axle.

The extruder is equipped with a pull-off device 38 with which the transport drum 10 can be pulled off the shaft 37, for e.g. to replace worn projections 13 or worn spacer rings 21, or to supply the transport drum with projections with other spacer combinations. The extraction device 38 is shown in its general form in fig. 1 and inserted in fig. 4.

The stripping device 38 has a mobile stand 39 which rests on rails 40 which are stored via an adjusting device 41 on the foundation 42. With the help of the adjusting device 41, the stripping device 38 can be aligned coaxially with respect to the transport drum 10. The stand 39 has a head 43 which, by means of the fastening devices 44, which in the present example are made of screws, are connected to the front side of the transport drum. A drive device 45 serves to move the stand in relation to the extruder's housing 8. In the present example, the drive device 45 has a spindle 46, which is driven by a spindle screw which in turn is moved by an electric motor 47

via a drive mechanism 48. The spindle 46 rests after exposing the transport drum and the axle on the front side of the latter and is fixed there appropriately by means of screws 49.

The stand 39 of the pull-off device 38 is guided on the rails by means of rollers 50 so that the stand when pulling off the transport drum, and which is indicated in fig. 1 with dotted lines, cannot overturn. In this way, the rails are appropriately shaped from C-profiles open from the side, whereby the rear rollers 50 a engage from the side in the C-profile so that the stand is secured in the vertical direction.

To remove the transport drum, as already indicated above, the housing plate 35 on the front side of the extruder is removed, whereby at the same time the bearing 36 together with its removable bearing sleeve on the shaft is removed, after which the transport drum 10, the shaft 37, the recess 9 of the housing 8 for the transport drum 10 as well as the liner 32 is completely exposed to any manipulation. To remove the transport drum 10", it is thus necessary to remove the ring flange 27 and the scraper 30 to the seal 25 on the side of the drum on the side of the inside of the machine, after which the drum can be removed using the removal device. For this purpose, the spindle 46 is first driven towards the front side of the shaft 37 and fixed with the help of the screws 49. Finally, the head 43

placed against the transport drum's front side and connected by means of the fixing devices 44 to the transport drum. After the drive device 45 is started, the transport drum is pulled off the shaft 37 and held by the pull-off device. After loosening the clamping device 23, the protrusions 13 and the spacer rings 21 can then be exchanged. The assembly takes place in the reverse order.

If the transport drum is removed, the liner 32 in the recess 9 of the housing 8 can also be replaced.

In contrast to the embodiment shown, the extraction device can be modified in different ways. Thus, it is e.g. conceivable that the drive device is not supported on the shaft 37, but on the housing 8. It would also be possible to

supply the pull-off device with a mandrel which lies coaxially in relation to the shaft 37, and which exhibits practically its outer diameter, so that the transport drum can be guided over this mandrel. To pull off the drum, spindles or other lifting devices could be used which attack directly on the front side of the transport drum. Thereby, the pull-off device could support itself via such a mandrel on the shaft.

As can be seen from Figures 1 and 2, the extruder in the present example is designed as a two-stage extruder. The first step forms the pre-press 2, which is designed as a screw press, and which, in addition to some processing of the material to be pressed, produces a primary pressure. The pre-press delivers the material further through a grid plate 51 to the connection channel 3,

which is connected via a suction line 52 with a suction device not shown in detail. The connection channel 3 is thereby evacuated, and thereby a greater density of the material to be pressed is achieved. The thus pre-treated material arrives at the inlet opening 11 in the extruder's second stage, i.e. the main press, whereby the supply roller 14 facilitates the supply of material to the spaces between the projections 13 of the transport drum 10. The material is taken in by the projections 13 of the transport drum 10 and bent with the help of the wiping comb 15

to the outlet opening 12.

In contrast to the embodiment example shown, the pre-press can advantageously also be designed as the second stage,

namely the mainstream press. For simple extrusion purposes, single-stage extruders are also sufficient, and these are then produced by a main press of the type shown. Figures 5 and 6 show further exemplary embodiments of the extruder, which are, however, equipped with rotating transport means (fig. 5 ) respectively a rotary transport means and a rotating wiping means (fig. 6). Fig. 5 shows the main press 101 of an extruder, which is designed analogously to the main press 1 from Figures 1 to 3, but which, however, has two rotating transport members designed as transport drums 110 a and 110 b. The transport drums 110 a and 110 b are arranged so that they rotate in the opposite direction in a recess 109 in the housing 108, and they contact each other with their projections 113 at point 100. From this point, the protrusions 113 slide in the direction of rotation along the liner 132 in the recess 109, and transport materials to two outlet openings 112 where the material is removed by the wiping combs 115 from the spaces between the protrusions. The supply of the material takes place for both transport drums 110a and 110b through an inlet opening 111. The supply roller in the main press 1 in figures 1 to 3 is omitted as their function is taken over by the transport drums.

The main press 201 in fig. 6 is analogous to the one designed and shown in fig. 1 to 3, whereby, however, instead of a wiping comb 15, there is a wiping drum 215 rotating in the same direction as the transport drum 210 in housing 208. The last-mentioned is likewise provided with projections 200, which, however, intervene in the spaces between the projections 213 and transport drum 210, whereby the the material transported in the interstices is guided in the direction of the outlet opening 212. For example, the interstices of the wiping drum can be removed with the help of a wiping edge 215 a. Similar to the main press in figures 1 to 3, a supply roller 214 with a cylindrical jacket is arranged here as well the inlet opening 211.

By arranging the protrusions at different distances on the transport means, namely the transport drum and/or the transport belt, an unusually uniform structure of the material string is obtained in the outlet opening. In addition, the extruder is distinguished by the use of two transport means by a very high performance,

which not only consists in a high production per unit of time and a low power requirement per unit of quantity transported, but above all also in an insensitivity to changes in the structure and consistency of the material to be extruded. The extruder

is suitable for materials with a high moisture content as well as for materials with an unusually low moisture content, i.e. almost dry material. A sealing of the extruder is practically not achieved.

The present extruder is not only particularly insensitive to changes in material properties, but can also be converted to materials of a different type by particularly simple changes to the device with the protrusions. By replacing the housing parts at the outlet opening, it is also possible to easily change the profile of the manufactured string. This is possible especially due to that the transport means can easily be adapted to the extrusion properties obtained by changing manufactured string profiles.

Claims (4)

1. Extruder for extruding a string of viscous material, especially of clay or clay-like material, with a rotating transport means, which is arranged in a housing provided with inlet and outlet openings, which transport means over its periphery has several over its width in the direction of rotation protrusions of the same height, which along part of the circulation path practically reach the wall of the house and transport the material along the house wall to the outlet opening, whereby a wiping device is arranged at the outlet opening which engages in the spaces between the projections, characterized in that the projections (13a, 13b , 113, 213) in the middle area of the transport member (10, 110a, 110b, 210) have a greater distance from each other than in the outer areas. 2. Extruder according to claim 1, characterized in that the distances between the protrusions (13, 113, 213) successively decrease from the center of the transport member (IO, 110a, 110b, 210) and outwards. 3. Extruder according to claim 1 or 2, characterized in that the distances between the projections (13, 113, 213) in the central area of the transport member (10, 110a, 110b, 210) are up to 2.5 times, preferably up to 1.5 times, the distances between the protrusions in the outer areas. 4. Extruder according to one of claims 1-3, where the transport means is made up of a transport drum, characterized in that the projections (13) are formed by rings or ring segments (19), which are arranged on a support cylinder (20), and which are separated from each other by means of ring or ring segment-shaped spacers (21) of varying width, whereby the spacers (21) and the rings or ring segments (19) are interchangeable and clamped together by means of a clamping device (23).