EP3445480A1

EP3445480A1 - Device for metering solids, in particular fibrous substances

Info

Publication number: EP3445480A1
Application number: EP17721969.8A
Authority: EP
Inventors: Norbert Marek
Original assignee: Brabender Technologie & Co KG GmbH
Current assignee: BRABENDER TECHNOLOGIE & Co KG GmbH
Priority date: 2016-04-22
Filing date: 2017-04-20
Publication date: 2019-02-27
Anticipated expiration: 2037-04-20
Also published as: EP3445480B1; WO2017182564A1

Abstract

A device for metering solids, in particular fibrous substances, such as natural fibres, glass fibres or carbon fibres, but also in particular for metering recycled materials such as edge trimmings from film extrusion, recycling usable materials, etc. through to powders, is characterized in that the central region (II) of the metering space is formed as a half-cylindrical trough, in that the chute (13) is formed by the slope that lies tangentially against both the walls of the agitator trough (4) and the walls of the screw trough (11) and in that the metering screw (5) has teeth on its outer circumference.

Description

Device for dosing solids, in particular fibrous substances

The invention relates to a device for metering solids, in particular fibrous materials such as natural fibers, glass fibers or carbon fibers, but also especially for the metering of recyclates such as edge trimmings in film extrusion,

Recycling of recyclables, etc. up to powders, according to the preamble of claim 1.

Examples of fibrous materials are natural and artificial long fibers (1 to 50 mm in length), scrim or fabric pieces, pressed mats (pieces),

Recyclate materials, eg. B. fiber-reinforced plastic recyclate.

The device should also be suitable for dosing other materials (powder, granules, fruit pieces).

State of the art

The metering of fiber materials, especially natural fibers, but also of other fibers and fiber-containing solids can lead to technical problems. The fibers agglomerate easily and form balls that are very difficult to separate again. Therefore, it is known in the art to

Facilitating dosing Use shredders or vibration means to move the fiber product into the dosing auger area, which then conveys it to the outside. Especially long fibers with a fiber length of more than 10 mm lead to

Difficult to dose with dosing screws. This applies in particular to renewable resources, ie natural fibers. But also recycled products, eg. B. made of glass fiber reinforced plastics are very difficult to dose for this reason.

So far available solid feeders solve the following problems only insufficient. Non-flowable materials do not get from the template to the discharge and to the discharge. The fibrous materials agglomerate and the agglomerates cause an irregular flow of material. When separating the agglomerates, damage or shortening of the fiber lengths may occur. The further processing of the shortened fibers may, depending on the application, lead to the production of rejects. Known Feststoffdosiergeräte are severely limited in terms of specific dimensions (fiber lengths) of the fibrous material to be metered and require that the specific dimensions remain the same. Because of these problems, for some fibrous materials, especially fibers with lengths of more than 10 mm, there is still no suitable solids metering device in the prior art.

A device according to the preamble of claim 1 is known from US 3,529,870 A. There are differences with the following characteristics:

Below the stirrer shaft and above the metering screw a trough-shaped interior with oblique, flat walls is provided. This arrangement means that the space adjoining this trough with oblique, planar walls above the agitator shaft contains considerable dead spaces which are not detected by the stirrer. Among other things, due to the oblique trough walls and the large number of dead spaces, bridging can therefore occur. To avoid this, a so-called "jogger" (loosener) is provided above the stirrer, which is expressly attached to avoid bridging.

The asymmetry can be found in US Pat. No. 3,529,870 A not only in the area of

Metering screw, but especially in the area between the agitator shaft and the metering screw shaft. Further differences: The dosing screw has no teeth. A

Height adjustment of the dosing screw is not recognizable. The outlet is horizontal here and is done with compressed air. There is no central axial cavity at the end of the dosing screw. DE 41 24 714 A1 discloses that saw teeth or needles are arranged on an opening roller surface in the form of a helical winding in order to extract individual fibers from a sliver.

Task and solution of the invention

Object of the invention: With a device for metering solids, in particular fibrous materials such as natural fibers, glass fibers or carbon fibers, but also especially for the dosage of recyclates such as edge trimmings

Film extrusion, recycling of recyclables, etc. up to powders, according to the preamble of claim 1, a problem-free and uniform dosage of fibers and fibrous material with fiber lengths of more than 10 mm by means of forced filling of the metering screw and with a residue-free promotion without bridging to be achieved, without that additional technical means such as "joggers" would have to be used.

This object is achieved by the features of claim 1, namely by a

Device for dosing solids,

with an inlet (1) in the upper area,

with an outlet in the design of a screw tube (6) or a vertical outlet (15) in the lower region,

with a stirrer (3) arranged below the inlet (1) with a horizontally arranged stirrer shaft (18) and with agitator blades (8),

with a metering screw (5) arranged below the stirrer (3) with a rotation axis (10) arranged parallel to the stirrer shaft (18),

the stirrer (3) being surrounded by an asymmetrical stirrer trough (4), the metering auger (5) being surrounded by a part-cylindrical auger trough (11),

wherein the asymmetric agitator trough (4) via a chute (13) to the

Partial cylindrical screw trough (11) connects,

wherein the inner wall of one of the two connection areas between the

asymmetrical stirrer trough (4) and the part-cylindrical screw trough (11) is formed as an inclined plane in the form of a chute (13), so that one of the

Agitator (8) of the stirrer (3) and the screw (5) unrecognized space (14) and a lateral and enlarged feed area of the metering screw is formed, wherein the stirrer (3) and the metering screw (5) for rotating in the same direction of rotation (19, 20) are set up,

the agitator blades (8) and the metering screw (5) moving downwards in the region of the chute (13) during rotation,

wherein the dosing space can be subdivided into three areas, which lie vertically one above the other,

the upper region (I) lying above a horizontal plane enclosing the stirrer shaft (18), the middle area (II) being below the upper area (I) and above a horizontal plane located between the spaces swept by the agitating blades (8) and the metering screw (5),

the lower area (III) being below the middle area (II),

wherein the lower region (III) of the metering space is formed as a part-cylindrical trough,

wherein the central region (II) and the lower region (III) adjoin one another directly on the one side, so that a recess (27) is formed, on the other side the transition between the central region (II) and the lower region (III) is formed by an oblique plane which bears tangentially both on the walls (26) of the agitator trough (4) and on the walls of the worm trough (11),

which is characterized

the middle region (II) of the metering chamber is formed as a semi-cylindrical trough,

that the chute (13) is formed by the oblique plane tangent to both the walls of the stirrer trough (4) and to the walls of the screw trough (11),

the metering screw (5) has teeth (23) on its outer circumference.

Particularly difficult in the prior art, the uniform filling of the

Discharge device. The problem is solved according to the invention with the stirrer, the use of a metering screw with teeth as Austragsorgan and the

asymmetric design of Rührwerkstrogs, the partially cylindrical design of the screw trough and the lateral filling of the metering screw via a chute and by the semi-cylindrical shape of the central region (II) of the metering.

Because the middle region (II) of the metering chamber is designed as a semi-cylindrical trough, no dead spaces are formed there. Corners and edges, where non-promoted material can accumulate, are also missing - unlike in the prior art.

A uniform promotion on that side of the dosing, where the metering screw is filled, without obstacles such as recesses, is achieved by the fact that the chute (13) is formed by the inclined plane, the tangential both on the walls of Rührwerkstrogs (4) also on the walls of the Screw trough (11) is applied. Therefore, no residues of the fiber material remain in the feed path to the metering screw.

Characterized in that the dosing screw (5) has teeth (23) on its outer circumference, resulting agglomerates, such as balls wound around the stirrer,

Gentle on materials separated and a continuous discharge is possible.

An essential difference of the fiber feeder according to the invention compared to the cited references is the shape of the metering space, namely:

The middle region of the metering chamber, namely between the horizontal plane in which the agitator shaft (3) lies, and the horizontal plane directly above the

Metering screw (5) is designed as a semi-cylindrical trough. The space swept by the impellers fills this area completely.

The area above this central area, that is above the agitator shaft, has vertical walls. The vertical walls immediately adjoin the upper edge of the semi-cylindrical trough. Due to the shape of the central region, bridging does not occur in this upper region and a "jogger" as in US 3,529,870 A is not necessary.

The lowermost region, namely the partially cylindrical screw trough is asymmetrical, with a free space (14) only on the side in which promotes the stirrer.

Particularly important is the semi-cylindrical space between the agitator shaft (3) and the dosing screw, which is symmetrical except for a small area adjacent to the free space (14) on the metering screw. The semi-cylindrical shape causes the interior of the device according to the invention is made considerably more compact. Here are the many empty spaces as in US 3,529,870 A, which favor bridging.

Since the semi-cylindrical trough for the metering screw (5) directly adjacent to the bottom of the semi-cylindrical trough of the stirrer (3), the shape of the entire interior is recessed. If this return is eliminated by applying an oblique plane tangentially to both the semi-cylindrical screw trough and the semi-cylindrical stirrer trough, this return disappears. Of the The resulting additional space is the "free space (14)" mentioned here, which occurs only on one side, as shown in Figure 7 of the present application

semi-cylindrical stirrer trough for semi-cylindrical screw trough without edge, so smooth. The transition is formed by an inclined plane, referred to herein as a "chute".

The teeth (23) are designed to pull fibrous matter from the chute (13) into the dosing screw (5) without damaging or dissolving the fibrous matter. For this purpose, the teeth (23) which are attached to the outer circumference of the metering screw (5) have a shape like the tilting vibrations in the electronics. That is, the front edge in the direction of movement falls steeply, the in

Moving direction behind flank falls off flat. The opening roller mentioned in DE 41 24 714 A1, on the other hand, is not designed to feed the material into the screw.

In contrast to the prior art, the invention in the promotion of fibers on forced delivery is set (agitator, dosing screw, speeds). For other materials to be metered, the invention is set as usual, that is without forced delivery.

Among other things, the following advantages are achieved:

The synergistic interaction of active and passive flow support ensures continuous screw filling. A residence time distribution is present.

The flow support becomes active through the stirrer (3) and passively through the stirrer

Execution of the troughs and the slide (13) with the lateral and large

Catchment area reached.

The separation of agglomerates is made possible by a special discharge. The discharge element consists of a metering screw (5). It is provided according to the invention with teeth. The discharge can optionally be optimized with a rotating impeller (7). The impeller is driven either by a vertical outlet with drive or by a in the metering screw (5) inside the second shaft. The delivery principle is based on the pressure of the inflowing fibers on the fibers lying in the chute. The stirrer (3) pushes the fibers through the chute into the lateral intake area of the metering screw.

Advantageous embodiments of the invention are set forth in the subclaims. So it is also suggested

that the space swept by the agitating blades (8) completely fills the central area (II),

the upper area (I) has vertical walls (25),

that the vertical walls (25) of the upper region (I) merge tangentially and without an edge into the walls (26) of the semi-cylindrical agitator trough (4),

that the upper area (I) of the metering space has a rectangular cross-section, that the agitator shaft (18) and the rotation axis (10) of the metering screw (5) are arranged vertically one above the other,

the distance between the agitator shaft (18) and the rotational axis (10) of the metering screw (5) is adjustable, in particular by means of a height adjustment of the metering screw (5),

the worm (5) has an impeller (7) at the discharge end (16),

the ratio of the speeds of rotation of the metering screw is adjustable.

The metering device can be adjusted according to different fiber lengths of the material to be metered, in particular by means of the height adjustment of

Dosing screw.

Previously non-recoverable materials can now be dosed in stable process windows and thus processed industrially.

With the optional height adjustment, the distance between stirrer and

Dosing screw to be adjusted. Thus, the optimal, dependent on the metering distance between stirrer and metering screw can be adjusted.

The dosing screw consists of a shaft (also called soul) and the

Schneckenflügeln (spiral). The soul is not over the complete

Screw flight length. The soul ends in front of the screw tube (or discharge tube). There is a central axial through cavity. The cavity serves to reduce the material pressure in the screw tube by compression is caused. Furthermore, the cavity for the connection of the optional Abwurfunterstützung (impeller 7) is required.

embodiment

In the following an embodiment of the invention will be described in more detail with reference to drawings. In all drawings, like reference numerals have the same meaning and therefore may be explained only once. Show it

Figure 1 is a perspective view of the entire inventive

Contraption,

Figure 2 is a perspective view of the entire inventive

Device, but without the optional attachment container (la) and without the vertical outlet with drive (15),

FIG. 3 shows a vertical section through the device according to FIG. 1 perpendicular to the axis of rotation of the stirrer or metering screw, viewed from the front,

FIG. 4 shows a vertical section through the device according to FIG. 1, parallel to the axis of rotation of the stirrer or metering screw, seen from the right side,

FIG. 5 is a perspective view of the metering screw (5),

FIG. 6 shows a detail A from FIG. 5,

Figure 7 is a schematic representation of the operation and

FIG. 8 shows the flow of material by forcing the stirrer over the material in the chute.

Structure of the inventive device

FIG. 1 shows the entire device according to the invention. The attachment container (1) is placed on a trough housing (2). The internal asymmetric

Stirrer trough (4) comprises the stirrer (3) and the partially cylindrical screw trough and the metering screw (5). Stirrer (3) and metering screw (5) are set in rotation by one drive (9) or several drives. On the front side sits on the screw tube (6) of the vertical outlet with drive (15). Figure 2 shows the device according to the invention without the optional attachment container (1) and without the vertical outlet with drive (15).

FIG. 3 shows a sectional view from the front view. The stirrer (3) promotes, from this direction in a clockwise direction, the material up to the metering screw (5). The direction of rotation is determined by the asymmetrical design of the agitator trough (4). The metering screw (5) conveys the material to be metered from the drawing sheet level. Stirrer (3) and metering screw (5) rotate in the same

Rotation.

Figure 4 shows a sectional view, in a view from the right side. Stirrer (3) and the metering screw (5) can be driven by two individual drives or by an additional gear and a common drive. The distance between stirrer (3) and metering screw (5) can be adjustable.

FIG. 5 shows the metering screw (5). The outer contour of the illustrated

Dosing screw is provided with teeth (23).

The device according to the invention is used to supply solids to a process. The process can be continuous or discontinuous. The device according to the invention is particularly advantageous for the following branches of industry:

• Chemical industry

• Plastics and rubber industry

• (animal) food, cosmetics and pharmaceutical industries

· and other.

Mode of operation of the device according to the invention During operation, the following steps take place continuously and simultaneously (see also FIGS. 7 to 8).

Step 1: The material to be dispensed is manually or through upstream

Process engineering in the attachment container (la) or the asymmetric

Agitator trough (4) abandoned.

Step 2: The material is caught by the relatively slowly rotating stirrer (3).

Either the material falls into the empty space (14) or it already presses in the empty space Room (14) existing material towards catchment area and it is then retracted through the teeth.

Step 3: The teeth (23) on the dosing screw (5) are able to separate agglomerates and thus ensure a better filling of the dosing screw (5). The material is conveyed in the axial direction through the screw tube to the end of the screw (16).

Step 4: The optional impeller (7) rotates at the discharge and supports the

Separation of agglomerates. The impeller (7) rotates in the direction of rotation (20) of the metering screw (5) and at a higher speed than the metering screw (5).

If the fibers agglomerate and form a ball of fibers around the stirrer (3) (Figure 8), the teeth (23) engage and singulate individual fibers (24) of the fiber nugget.

The fibers (24) are pressed into the chute (13) via the stirrer. Nachgefördertes material pushes the material in the slide to the discharge. This results in the advantageous asymmetrical design of the agitator trough (4) according to the invention and of the part-cylindrical screw trough (11) and the chute (13). Due to the lateral and large catchment area and the teeth of the dosing screw, it is optimally filled. Depending on the specific geometry of the material to be dosed, the height adjustment of the dosing screw can be used to determine the degree of filling of the dosing screw

Dosing screw to improve. Another way to optimize the Dosierschneckenfüllgrad lies in the

Adjustment of the ratio between metering screw speed and stirrer speed.

The above-mentioned materials to be dosed are the focus of particularly innovative industries, such. B. the auto industry, the aerospace and the

Defense industry. Among other things, the invention makes it possible to develop new fiber composite materials. It can also be used to advantage in recycled fiber composites because it is capable of metering high cost blank waste from fabric mats. The invention therefore has a high priority for the high technology industry.

The geometries of the metering screw and the conveyor are preferably matched to the metered solids and adapted to it. The im Embodiment illustrated parts are only examples. Such geometric parameters are for example:

a. Diameter of the dosing screw

b. Number of teeth on the dosing screw

c. Size and length of the teeth

d. Length of agitator blades

e. Basic body of the agitator wing (round, flat ...)

f. Annexes to the wing (crowds, pins ...)

G. the room above the slide

H. Number of agitator blades

i. Alignment of the agitator wings to each other

j. Ratio of diameter of the dosing screw to the diameter of the screw tube

k. Slope of the dosing screw

1. Different gradients on the dosing screw to reduce the

Pressure / compaction in the screw tube

m. Channel depth of the dosing screw

n. One-handed or multi-course dosing screws

o. Diameter of the screw tube

p. Depth of the asymmetric agitator trough, the partially cylindrical

Helical troughs and the slide

q. Design / Layout of the asymmetric stirring electrode

r. Design / layout of the partially cylindrical screw trough

s. Design / layout of the slide

In summary, important advantageous features of the novel device are:

• the lateral catchment area,

• the large catchment area,

The height adjustability of the metering screw (5),

· The adjustability of the ratio of the speeds from stirrer to

dosing screw,

The asymmetrical design of the stirring electrode,

The partially cylindrical design of the screw trough,

• the slide,

· The room above the slide,

• the equalization of the discharge by a vertical outlet with

Drive, • the teeth on the dosing screw and

• the design of the agitator or agitator blades.

Other important features:

An asymmetrical trough 4 with a free space (14) is provided, wherein there are no dead spaces in the dosing space below the agitator shaft (18), except in the area of the dosing screw (space (14)). The metering chamber has a rectangular cross-section and vertical walls above the agitator shaft (18).

Below the agitator shaft (18) and above the metering screw (5), a semi-cylindrical screw trough is provided, which is adapted to the rotating arms of the agitator shaft (18). In other words, the space swept by the stirrer blades (8) completely fills this area of the metering interior.

The vertical walls above the agitator shaft (18) connect directly to the semi-cylindrical trough (4) below the agitator shaft (18) and above the metering screw (5).

The asymmetry is provided essentially only in the area of the metering screw (5). That is, the portion of the metering screw below the stirrer is asymmetrical and has a free space (14) at the side into which the agitator is conveyed.

The stirrer (3) has such a direction of rotation (19), so that the product is first conveyed down into the space (14) and then to the metering screw (5). The stirring blades (8) are wire-shaped.

A vertical outlet (15) with a drive and an impeller (7) is provided, wherein the impeller (7) rotates faster than the metering screw (5). In addition, a central axial cavity is provided at the end of the metering screw. LIST OF REFERENCE NUMBERS

inlet

Attachment container (optional)

Trough housing (optional)

stirrer

asymmetric agitator trough

dosing screw

screw tube

impeller

impellers

drive

axis of rotation

partly cylindrical snail trough

Height adjustment dosing screw

Slide, sloping plane

room

vertical outlet with drive

End of the snail

Stirrer shaft

Direction of rotation of the stirrer 3

Direction of rotation of the dosing screw 5 tooth

fiber material

vertical wall of upper section (I) wall of agitator trough (4)

return

the upper area of the dosing space, the middle area of the dosing space, the lower area of the dosing space

Claims

Device for dosing solids,

with an inlet (1) in the upper area,

with a stirrer (3) arranged below the inlet (1) with a horizontally arranged stirrer shaft (18) and with agitating blades (8), with a metering screw (5) arranged below the stirrer (3) with a parallel to the stirrer shaft (18) arranged axis of rotation (10),

wherein the stirrer (3) is surrounded by an asymmetrical stirrer trough (4),

wherein the metering screw (5) is surrounded by a part-cylindrical screw trough (11),

wherein the asymmetrical agitator trough (4) via a chute (13) to the part-cylindrical screw trough (11) connects,

wherein the inner wall of one of the two connection areas between the asymmetric agitator trough (4) and the partially cylindrical worm trough (11) is formed as an inclined plane in the form of a chute (13), so that one of the agitator blades (8) of the stirrer (3) and the Snail (5) unperceived space (14) and a lateral and enlarged catchment area of

Dosing screw is formed,

wherein the stirrer (3) and the metering screw (5) are arranged to rotate in the same direction of rotation (19, 20),

wherein the upper region (I) above a stirrer shaft (18)

enclosing horizontal plane,

the central area (II) being below the upper area (I) and above a horizontal plane located between the spaces swept by the agitating blades (8) and the metering screw (5), the lower area (III ) is located below the central region (II), wherein the lower region (III) of the metering chamber is formed as a part-cylindrical trough, wherein the central region (II) and the lower region (III) adjoin one another directly on the one side, so that a recess (27) is formed, on the other side the transition between the central region (II) and the lower region (III) is formed by an oblique plane which bears tangentially both on the walls (26) of the agitator trough (4) and on the walls of the worm trough (11),

characterized ,

the metering screw (5) has teeth (23) on its outer circumference.

2. Device for metering solids, in particular fibrous substances according to claim 1,

characterized ,

that the space swept by the agitating blades (8) completely fills the central area (II).

3. Device for metering solids, in particular fibrous substances according to claim 1,

characterized ,

the upper area (I) has vertical walls (25).

4. Device for metering solids, in particular fibrous substances according to claim 3,

characterized ,

the vertical walls (25) of the upper region (I) merge tangentially and without an edge into the walls (26) of the semi-cylindrical agitator trough (4).

5. Device for dosing solids, in particular fibrous substances according to claim 1,

characterized ,

the upper area (I) of the dosing space has a rectangular cross-section. Device for metering solids, in particular fibrous substances, according to claim 1,

characterized ,

the stirrer shaft (18) and the rotation axis (10) of the metering screw (5) are arranged vertically one above the other.

Device for metering solids, in particular fibrous substances, according to claim 1,

characterized ,

the distance between the agitator shaft (18) and the axis of rotation (10) of the

Dosing screw (5) is adjustable.

characterized ,

the worm (5) has an impeller (7) at the discharge end (16).

characterized ,

the ratio of the speeds of rotation of the metering screw is adjustable.