DD140653A1 - STATIC MIX AND HOMOGENIZATION DEVICE - Google Patents

Abstract

The invention relates to a static mixing and Homogenizer for mixing plastic or viscous Masses, especially in piping systems. The goal exists in the simple constructive solution and the improvement of Quality of the flowing melt and the use value behavior of the spun threads. The object of the invention is in the strong homogenization of the residence time spectrum of Melt particles between the pipe wall and the center of the pipe. The problem is solved by the fact that the circular or triangular in the cascade and offset arranged Mixing discs incorporated recess in the range between 5 and 49% of the flow cross-section of the tube is. The solution according to the invention is for mixing and homogenizing, especially in extrusion plants for plastics processing, used. -

Description

7 3

Title of the invention

Static mixing and Horaogenisiervorrichtung

Field of application of the invention

The invention relates to a static mixing and homogenizing device for mixing plastic or viscous masses, in particular in piping systems.

Characteristic of the known technical solutions

Devices for mixing and homogenizing plastic or viscous masses are known in various embodiments.

According to GB-PS 1 238 506 a device is known, which divides the melt stream within a tube into y ^x partial melt streams (y = 4 and χ = number of elements) by their structural design, with melt particles from the tube wall to the center of the tube and vice versa be relocated.

A disadvantage of this solution is that the production cost is very high and no 100% replacement of flowing on the * pipe wall melted particles takes place. To improve the homogeneity of the melt, a further solution from GB-PS 1 220 688 is known, which mixes the melt by axial and radial division or, rearrangement operations. The angular flow channel and the speed gradients prevailing therein and the difficult, complex production are unfavorable features of this mixer. Furthermore, the limits. resulting pressure drop the combination length of the mixer both according to GB-PS 1 238 506 and after the GB-PS T 220 688 a strong.

In GB-PS 1 360 751 a spiral mixing element is protected, with which the layer formation according to the law y ^x erf.folgt, where y = 2 and χ = represents the number of individual elements. This solution has the advantage that in addition to the mixing effect by layer formation on the left-right arrangement of the spiral elements, an additional turbulence is generated, which supports the mixing, effect. The prerequisite for the full functionality of this mixer is that the elements must be ground into the molten tube in order to achieve a perfect contact with the pipe wall. The grinding in is necessary so that there is not too much play between the pipe wall and the mixing elements. Too large a game would cause the near-wall melt layers, which is particularly strong to replace, continue to flow in the existing game between mixer element and pipe wall, without being involved in the mixing process. The grinding process of such Spiralmischeiemente is extremely complex and costly at the same time.

Object of the invention

The object of the invention to provide a static mixing and homogenizing, in particular for distribution lines, to be designed so that by a simple constructive solution, the quality of the flowing melt and the Gebrauchsv / ertverhalten of the spun yarns or "improve the ¹ end products produced therefrom.

Explanation of the essence of the invention

The invention has for its object to provide a static mixing and homogenizing, especially for melt lines, with which the residence time spectrum of the melt particles between tube wall and center of the pipe is greatly homogenized and thus, especially in offset with thermally sensitive dyes melting within a certain limits uniform residence time between pipe center and pipe wall is achieved.

According to the invention the object is achieved in that cascading mixing discs are arranged in the interior of a shrimp-carrying tube, the recess is in the range between 5 and 49 % of the flow cross-section of the tube and the recesses are offset from each other so that in the flow direction no preferential flow is formed, wherein 51 bis 95 % of the melt particles are separated from the pipe wall when passing through the individual mixing disks and mixed with melt particles of the remaining flow cross section.

The mixing disks are designed so that their end faces are evenly inclined towards the center of the disk, and the recess is circular or triangular Conditionally slowly flowing Schmelzzerandschichten forced peeled away, led to the center of the mixing disk and accelerated in the recess by the existing speed differentials of the individual-flow components, with a particularly good mixing effect of slow and fast flowing melt layers is achieved.This interplay of mixing between the particularly slowly flowing Edge melt layers and the rapidly flowing regions are repeated within the cascaded arrangement according to the invention in accordance with the number of mixing disks ren tube length and a reasonable pressure drop, the mixing discs can be worked in the range of 5 to 49 % of the flow cross-section of the tube. By varying the inclination or curvature of the end faces of the mixing disks, the detachment process of the slowly flowing melt layers on the pipe wall can take place intensively but also very gently. This depends on which pressure drop or which temperature control or temperature increase are permissible in the mixing and homogenizing device according to the invention. Of course, the design of the mixing disks is very much dependent on the melt viscosity. Pure high-viscosity melts, the recesses are preferably between 25 and 49 % and to choose for low-viscosity melts between 5 and 25 % of the flow cross-section of the tube. In order to keep the pressure drop within practically acceptable limits, the curvatures or inclinations of the end faces of the mixing disks must be matched to the melt viscosity. It is true that with growing

the melt viscosity the inclination or curvature of the end faces of the mixing disks is to be selected larger, d. that the detachment process should be gentler and more uniform «

embodiment

The invention is intended to be closer to an embodiment

be explained.

In the accompanying drawings show;

Fig. 1: section through a cascade mixer

Fig. 2: section A-A after Pig. I

Pig. 3; Section B-B of FIG. 1

4 shows section C-O of FIG. 1

5 shows section D-D according to FIG. 1

6 shows section E-E of FIG. 1

FIG. 7: ϊ section FF according to FIG. 1

8: section G-G of FIG. 1

Fig. 9: Top view of a mixing disk with a circular cut-out and curved end faces

10 shows the section H-H of FIG.

11 shows a plan view of a mixing disk with triangular

shaped cutout and curved end faces

Pig. 12: the section I-I in FIG. 11

Pig. 13: Top view of a mixing disk with a circular cut-out and continuously inclined. End faces.

Pig. 14: the cut K-K after Pig. 13

15t top view of a mixing disk with a triangular cutout and continuously inclined end faces

Pig. 16: the cut L-L to Pig. 15

Pig. 1 shows the solution according to the invention in section with mixing disks 1. The mixing disks 1 can be centered and locked in the molten pipe 5 by a shaft (not shown). The melt supplied by the melting is forced by the mixing disk 1 at the curved end faces 2 necessarily centered and accelerated again in the region of the recess 3, wherein in the region of the recess partially limiting cutting line 4 melt layers of the near-edge region with melt layers from the middle region of the otherwise laminar melt flow are brought together and mixed.

In Pig. 2 to 8 (section A-A to section G-G), the advantageous arrangement of the mixing discs 1 and indeed shown so that no preferential flow is present in the mixing and homogenizing. By choosing the size and the geometry of the recess 3, the solution according to the invention can be adapted to the most diverse melt modifications.

Due to the courageous centering of the mixing disks 1 via the V / elle not shown and the tension of the mixing-cheeses 1 against each other, a smooth grinding of the outer diameter of the mixing disks 1 of the device is possible. The incorporation of the recesses 3 can be done after the grinding. FIGS. 9 to 16 show variants of the mixing disks 1 with the associated sections H-H to L-L. Pig. 9 shows a mixing disk with a circular recess 3, which is delimited by the section line 4 and the wall of the pipe 5.

From Pig. 10, the curved end faces 2 can be seen * The cascaded arrangement of these mixing discs is from the sectional view of Pig. 1 and the associated pig. 2 to 8 show.

A mixing disk 1 with triangular recess 3 ", which is bounded by the end face 6 and the V / orung of the tube is in Pig. 11 shown.

The Pig * 12 shows the corresponding section with the curved end faces 2.

Pig · 13 his 16 show similar mixing discs 1, except that the end faces 6 are inclined towards the center instead of curved steadily.

Claims (2)

- 8th - Erfindungganspruch Static mixing and homogenizing device for mixing plastic or viscous masses, consisting of a molten tube in which mixing disks are centered by a shaft, characterized in that the recess (circular or triangular in the cascaded and offset mixing disks (1) incorporated recess ( 3) in the range between 5 and 49 % of the flow cross-section of the tube (5). 2. Static mixing and homogenizing apparatus according to item 1, characterized in that the mixing disks (1) can be combined Dazu_2 / pages Zeiduiunüen