DE10351973B4 - Roll part of a planetary roller extruder - Google Patents

Abstract

Roller part (1) of a planetary roller extruder for degassing material,
wherein the roller part (1) along the circumference has an axially extending recess (5), on which a degassing dome (6) is arranged and on which a vacuum can be applied,
characterized in that
the length of the recess (5) is 80% of the length of the roller part (1).

Description

The The invention relates to a roller part of a planetary roller extruder for Degassing material, the roller part along the circumference a recess extending in the axial direction a degassing dome is arranged and to which a vacuum can be applied is.

Generic devices are known in the art. To a perfect extrusion processing to ensure it is necessary that e.g. the moisture content of the material does not exceed a certain value. If the humidity is too high, either dry the material or, what is possible with most materials, moisture by vacuum degassing during extrusion to the necessary minimum to reduce.

For example, in the DE 200 03 297 U1 a planetary roller system is described in which a transfer part is arranged between a first planetary roller extruder and a second planetary roller extruder. The material falls from the first planetary roller extruder through this transfer part in the second planetary roller extruder. The transfer part can be hermetically sealed and designed as a chute. At the transfer part, a vacuum can still be applied and via a suction corresponding gases are removed from the material. Devices for degassing material from at least one feed unit, a degassing unit and a discharge unit are also known from the DE 1 679 881 A known. The DE 100 09 843 A1 describes a planetary roller extruder section having a recess for degassing.

A another possibility Degassing is the attachment of a corresponding device between two planetary roller parts.

Under Degassing is practiced under more or less strong vacuum Extraction of water or water vapor or of recipe components, such as plasticizers or other desired or undesirable Components required by the planetary roller extruder and to understand recycled materials. In addition to plastic compounds, this can various mixtures used in food technology, chem. Industry, adhesive production etc. find use and with help of the planetary roller extruder.

The Degassing at the end of the roller part is in so-called. EV machines and Cascade machines applied. The EV machine is the one on the roller part flanged single screw corresponding geometrically designed to to allow the application of a vacuum. In cascade extruders, the degassing takes place in the so-called transfer box, as a junction box of the two stages, instead.

The Degassing in the roller part is so far between two parts in Area of so-called start-up or dispersing created. It will the vacuum over openings passed in the start-up or dispersing ring in the roller part.

• a.) die Oberflächen des zu entgasenden Stoffes möglichst groß gehalten werden,
• b.) die Oberflächen des zu entgasenden Stoffes regelmäßig erneuert werden,
• c.) ein niedriger absoluter Druck herrscht,
• d.) große Querschnitte in den Förderleitungen vorhanden sind, um große Mengen des Gases vom entgasten Stoff wegzufördern.

An ideal degassing is given if the following conditions are met:

• a.) the surfaces of the substance to be degassed are kept as large as possible,
• b.) the surfaces of the substance to be degassed are renewed regularly,
• c.) a low absolute pressure prevails,
• d.) large cross-sections are present in the delivery lines to promote large amounts of the gas from the degassed material.

The meet previously known systems the above conditions are not complete. In a cascade extruder and in an EV machine only the conditions a.), c.) and d.), where in the degassing between the roll parts the condition d.) Not can be complied with. Thus, in the known systems a ideal degassing not performed become.

task The invention is to modify a known system such that all mentioned Conditions a) to d) for an ideal degassing prevail.

The solution The object is in connection with the preamble of the claim 1 achieved by the length Recess 80% of the length of the roller part is.

By this improvement will allow a big Cross section to create, in which there is a low absolute pressure and one possible size surface ready for the substance to be degassed. In a planetary roller extruder For example, turning the spindles also becomes the point b) fulfilled, namely, that the surface the substance to be degassed is renewed regularly. The recess may extend to the centerline of a roll member, i. be open at 180 °. practical Experiments have shown that an opening angle of 90 ° makes sense is. But it is also conceivable to choose an angle between 10 ° and 180 °.

Thus, the length of the recess is 80% of the length of the corresponding roller part of a planetary roller extruder, but 150 mm of the respective partial area of the roller cylinder length ste guide the planetary roller available should be.

Consequently could For example, a 500 mm long roller segment over a length of 300 mm open become. Advantageously, this opening is located in the upper region of the Rolling part. In the area where the roller part is not recessed is, in particular the remaining 20%, the gearing partners in a known manner from main spindle, planetary spindles and roll cylinders formed to the so-called sun gear. The planetary spindles are thus in entry and exit area over the entire circumference of the Sun wheel stored.

As at conventional Planetary roller extruders is the proposed degassing extruder Main spindle driven and the planetary spindles are located in a rotational movement and are also in circulation around the main spindle. When degassing extruder based on the planetary roller extruder is Partially filled the part of the machine used for degassing. The partial filling can over it Underdosing, cheap assembly with planetary spindles or variation of the planetary spindles themselves, In particular, here the modification of the planetary spindle geometry via so-called. Grooves in the different versions is addressed. Upstream and downstream sections of the extruder are designed to be filled, what by appropriate equipment can be done with planetary spindles and / or there is the vacuum termination of a Roll section to the next on the sufficient dimensioning of upstream and downstream start-up or dispersing rings. The vacuum itself engages in a roll section and uses the enormous surface renewal, which is known to take place in a planetary roller extruder.

Of the opened Part of the roller part is provided with a sufficiently dimensioned Vacuum chamber or vacuum dome provided. This creates an enormous greater Cross-section for the removal of gases and volatiles.

conditioned by the attached recess in the roller part, the helical on Circumference of the roll cylinder arranged Tem perierungskanäle interrupted. To ensure proper temperature control ensure the temperature control channels are connected in this area with Temperierkanalbrücken, so that the tempering continues to continue through the roll cylinder be guided can.

In The drawings schematically show the device

1 shows a cut-off degassing unit with a vacuum degassing and

2 represents this part of the degassing in a cross section.

1 shows a portion of a cut degassing unit 10 , here a roller part 1 a planetary roller extruder was selected and consequently the roll cylinder 2 and the tempering channels 8th you can see. The upper area of the roll cylinder 2 is partially cut open and has a recess 5 on. In this recess 5 is a degassing dome 6 arranged, which has a vacuum connection 9 having. To ensure proper temperature control, adjacent temperature control channels are connected to temperature channel bridges.

The schematic representation according to 2 illustrates the described opening angle ζ. In this cross-sectional view of a roller part 1 again is the roll cylinder 2 to see in which the main spindle 3 and the planetary spindles 4 form a sun gear. The recess 5 in the roller part 1 , which extends in the axial direction, here is 90 °. This angle is determined around the extrusion axis and from beginning to end of the opening in the roll cylinder 2 measured. In the recess 5 is a degassing dome 6 arranged. The Entga sungsdom 6 has a vacuum connection 9 on, which, as shown here, offset by 90 ° to the presentation like. 1 can be arranged.

The described and illustrated in the figures improvement of a known planetary roller system meets all conditions of a ideal degassing.

1

roller part

2

rolling cylinders

3

main spindle

4

Planet spindle

5

Recess in the roll cylinder 2

6

degassing dome

7

Temperierkanalbrücke

8th

tempering

9

vacuum port

ζ

opening angle

Claims (5)

Roller part ( 1 ) of a planetary roller extruder for degassing material, wherein the roller part ( 1 ) along the circumference an axially extending recess ( 5 ), at which a degassing dome ( 6 ) is arranged and on which a vacuum can be applied, characterized in that the length of the recess ( 5 ) 80% of the length of the roller part ( 1 ) is. Roller part ( 1 ) of a planetary roller extruder according to claim 1, characterized in that the recess ( 5 ) has an opening angle (ζ) between 10 ° and 180 °, preferably 90 °. Roller part ( 1 ) of a planetary roller extruder according to claim 1, characterized in that the recess ( 5 ) in the upper region of the roller part ( 1 ) is attached. Roller part ( 1 ) of a planetary roller extruder according to claim 3, characterized in that in the non-recessed area of the roller part ( 1 ) the main spindle ( 3 ), the planetary rollers ( 4 ) and the roll cylinder ( 2 ) form a sun gear system. Roller part according to one of claims 1-4, characterized in that in the region of the recess ( 5 ) Tempering channel bridges ( 7 ) are arranged.