EP0980703A1 - Static mixer - Google Patents

Abstract

The frames (501 - 504 and 511 - 514) are drawn through at crossing points (320) of the heat carrier channels (580, 581, 590, 591,592). The static mixer insert comprises two or more neighboring layers and parallel frames. The frames of each neighboring layer are crossed by frames. The frames are connected to each other at the crossing points

Description

It becomes a heatable or coolable, static mixer insert and a heatable one or coolable, static mixer described with at least one mixer insert, in which the mixer insert consists of at least two or more arranged side by side Layers of webs, in particular parallel to one another, is built up, wherein the webs of adjacent layers of webs intersect and the webs on the Crossing points of the web layers are interconnected and in which the web layers are crossed at the intersection of heat transfer channels.

Static mixers are often used to mix liquids: One Pump presses the liquid through a static mixer built-in Pipe, the liquid being sheared at the mixer and divided into partial flows that are to be mixed together.

The following two devices may be mentioned as examples of static mixers.

Mischen beim Herstellen und Verarbeiten von Kunststoffen" , Herausgeber VDI Ges. Kunststofftechnik, VDI-Verlag 1986, S. 238-241) wird die Flüssigkeitsströmung des Mischgutes durch ein im Rohr eingebautes Trennblech in Teilströme geteilt. Dieses Trennblech ist um die Rohrachse tordiert. In jedem der Teilströme der Flüssigkeit entsteht eine wirbelförmige Strömung, die zur Umverteilung der Flüssigkeit im Querschnitt des Rohres führt. Mehrere solcher Mischelemente werden in der Praxis hintereinander angeordnet, um die Flüssigkeit immer wieder neu zu teilen und ein hinreichendes Mischergebnis zu erzielen. Die Druckstabilität dieser Mischer gegenüber hochviskosen Fluiden ist jedoch vergleichsweise gering.With the so-called Kenics mixers (see

Mixing in the manufacture and processing of plastics ", publisher VDI Ges. Kunststofftechnik, VDI-Verlag 1986, pp. 238-241), the liquid flow of the mixed material is divided into partial flows by a partition plate installed in the tube. This partition plate is twisted around the tube axis. In Each of the partial flows of the liquid creates a vortex-shaped flow, which leads to the redistribution of the liquid in the cross-section of the tube. In practice, several such mixing elements are arranged one after the other in order to divide the liquid again and again and to achieve an adequate mixing result compared to highly viscous fluids is comparatively low.

The so-called SMX mixers (cf. US Pat. No. 4,062,524) consist of two or more mutually perpendicular grids of parallel sheet metal strips that are welded together at their crossing points and at an angle are set against the main flow direction of the mix to the liquid to be able to divide and mix. The manufacturing cost for these mixers is because of the many welded joints to be made relatively high.

The heat exchange of highly viscous liquids when they pass through known ones Heat exchangers typically take place at a very low Reynolds number. If, for example, smooth pipes are used for heat exchange, one is against Zero Reynolds number the heat exchange rate extremely low and on the part of the For a given throughput, the heat exchanger essentially only depends on the pipe length used. A significant improvement in heat exchange is then possible by combining the tubular heat exchanger with a static one Mixing device.

This combination is known in two forms. For one, in the Tubes of a tube bundle heat exchanger static mixing elements are used. The mixing elements from Kenics are used here in particular. On the other hand the pipes can be used as elements of a static mixer. This is described for example in German Offenlegungsschrift DE-A-2 839 564.

The use of a tube bundle heat exchanger through which the product flows does not apply but in many chemical processes. If e.g. a polymerization reaction must be cooled, is in a slower flow tube due to the higher residence time of the reactants reached a higher degree of polymerization. The Liquid in the pipe may become more viscous than in the neighboring pipes. This further slows the flow rate of the mix. With certain process parameters, tubes of a shell-and-tube heat exchanger can therefore be used clogged by polymer.

In such processes, a static one is formed from heat exchanger tubes Mixers as described in DE-A 2 839 564 are preferable. The manufacturing effort to produce this mixer is so high, however, that this solution is often called is rejected economically.

The object of the invention is to provide a static mixer that can be cooled or is heatable and can be produced in a comparatively simple manner.

The object is achieved according to the invention by the one described below static mixer use and in particular by the static described further Mixer.

The invention relates to a static mixer insert, consisting at least from two or more layers arranged next to one another, in particular to one another parallel webs, the webs being adjacent layers of webs cross and the webs are connected to each other at the crossing points characterized in that the web positions at their crossing points of heat transfer channels are crossed.

The heat transfer channels preferably run at an angle alpha 60 60 ° to Level of the jetty.

The heat transfer ducts can be separated into individual supply and discharge lines Heat transfer medium open.

A preferred variant of the static mixer insert is designed so that the Webs are at least partially designed as hollow webs, the additional channels for have a heat transfer medium.

The webs are in a preferred embodiment of the mixer to the main flow direction of the mix at an angle, in particular from 30 to 50 ° or from -30 up to -50 °, which ensures a good division of the mix flow into partial flows is effected.

In a variant of the static mixer insert, the heat transfer channels are or the channels that run through the hollow webs meandering at their entrances and exits connected with each other. This creates a composite of heat transfer lines created that only a few supply and discharge lines for the heat transfer medium having.

The invention also relates to a static mixer insert, consisting at least from two or more layers arranged next to one another, in particular webs parallel to each other, in particular with a rectangular cross-section, whereby cross the webs of adjacent layers of webs and the webs on the Junction points are interconnected, characterized in that the Bridges are designed as hollow webs, which have channels for a heat transfer medium. In this independent version, the mixer insert is not on the Crossing points penetrated by additional heat transfer channels through the Jetty runs.

The heat transfer channels can also be used with this type of static mixer insert lead into individual supply lines and discharge lines for a heat transfer medium.

Preferred in both independent forms of static mixer inserts Bars designed as straight bars.

Likewise, the webs of this design, which are only equipped with hollow webs as channels is at an angle to the main flow direction of the mixture, in particular from 30 to 50 ° or from -30 to -50 °.

The heat transfer channels of this static mixer insert can also be meandering be connected at their entrances and exits.

Another object of the invention is a static mixer consisting of at least one of the mixer inserts according to the invention mentioned and an inner housing, that encloses the mixer insert and in the openings for the supply line and derivation of the heat transfer medium either to the crossing the web layers Heat transfer channels or to the channels running along the webs or to both are provided.

The heat transfer channels or the channels of the hollow webs are preferably directly connected to the Openings in the inner housing are connected.

A particularly preferred static mixer is constructed so that the inner housing is still enclosed by an additional outer housing, the at least one Has inlet connection and an outlet connection for the heat transfer medium and with the inner housing an inlet space and an outlet space for the heat transfer medium forms and has an inlet and an outlet for the mix.

To improve the mixing effect are in a particularly preferred form static mixer several mixer inserts arranged one above the other in the inner housing and adjacent mixer inserts are mutually about their central axis twisted arranged.

The structure of the static mixer element according to the invention and of the invention static mixer allows this by injection molding one Manufacture workpiece, from the webs and from the heat transfer channels pierced inner case walls by adding sliders in the injection mold create the spaces between the webs and the heat transfer channels. This workpiece can either be itself in an outer housing, e.g. a pipeline, be installed or serve as a lost model for the investment casting.

Accordingly, an embodiment is obtained simply by a Master molding process a block consisting of the webs with the heat transfer channels, will be produced.

In a particularly preferred form, each web of a web position ends up to a maximum a web only at one end of the web on an inner housing wall, while the shows other end in the product stream. This design enables injection molding to spray all inner housing walls together with the webs, as all Spaces between the webs are accessible to sliders. This will make the Joining effort to complete mixer reduced.

Accordingly, a manufacturing method is particularly preferred in which in a primary molding process, the part of the inner housing walls that the Heat transfer channels is pierced with is produced.

With the provision of the mixer insert or mixer according to the invention the heat transfer from the heat transfer medium to the mix improves because the Heat conduction paths from the heat transfer medium to the product can be shortened.

In a preferred embodiment, several static mixers, if necessary also in any combination with known static mixers combined in a mixer module connected in series.

Especially when the successive static mixer inserts against each other are twisted by 90 °, a particularly good mixing effect reached.

Due to the low manufacturing costs for the primary molding process, the described heatable or coolable static mixer not only applied there where static mixing is required, but can be done from a cost standpoint other heat exchangers, e.g. Shell and tube heat exchangers as Capacitors, replace.

The invention is explained in more detail below with reference to figures, without thereby restricting the invention in detail.

Fig. 1a

die Vorderansicht eines erfindungsgemäßen Mischers

Fig. 1b

die Draufsicht auf den Mischer aus Fig. 1a

Fig. 1c

die perspektivische Ansicht des Mischers aus Fig. 1a

Fig. 2

die perspektivische Ansicht der Einbauten des Mischers aus Fig. 1a

Fig. 3a

die Vorderansicht eines Mischelementes des Mischers aus Fig. 1a

Fig. 3b

die Draufsicht auf das Mischelement aus Fig. 3a

Fig. 3c

die perspektivische Ansicht des Mischelementes aus Fig. 3a

Fig. 4

einen Schnitt durch das Mischelement aus Fig. 3a ensprechend der in Fig. 3b eingezeichneten Schnittlinie A-A

Fig. 5

die perspektivische Ansicht eines Mischelementes ohne Heiz-/Kühlkanäle in Richtung der Stege

Fig. 6

einen Schnitt durch das Mischelement aus Fig. 5 analog zur Schnittlinie A-A aus Fig. 3b

Show it:

Fig. 1a

the front view of a mixer according to the invention

Fig. 1b

the top view of the mixer from Fig. 1a

Fig. 1c

the perspective view of the mixer of Fig. 1a

Fig. 2

the perspective view of the internals of the mixer of Fig. 1a

Fig. 3a

the front view of a mixing element of the mixer from Fig. 1a

Fig. 3b

the top view of the mixing element from Fig. 3a

Fig. 3c

the perspective view of the mixing element of Fig. 3a

Fig. 4

a section through the mixing element of Fig. 3a corresponding to the section line AA drawn in Fig. 3b

Fig. 5

the perspective view of a mixing element without heating / cooling channels in the direction of the webs

Fig. 6

a section through the mixing element of FIG. 5 analogous to section line AA from FIG. 3b

Examples example 1

FIGS. 1a to c show an inventive device from different views Mixer. The outer housing is only shown schematically. The mixer consists of an outer housing 1 with product inlet connection 2, product outlet connection 3 and inlet nozzle 4, 6 and outlet nozzle 5, 7 for the heating / cooling medium and the mixer inserts 8, 10 with inner housing 11.

The internals shown in FIG. 2 are located inside the mixer made of 90 ° rotated against each other, stacked mixing elements 8, 10, which are separated from one another by separating plates 9 on the temperature medium side to control the flow direction of the temperature control medium. With others Arrangement of the dividers can reduce the number of heating / cooling medium nozzles are accepting a higher pressure drop.

Figures 3a to c show a mixing element (8) from different views. It consists of the inner housing section 300 and alternating layers of parallel Ridges 301 to 306 or 311 to 317 (in part only recognizable in section in Figure 4). The Bars of two successive layers of bars intersect under one Angle of 90 ° and have an angle of 45 ° to the product flow direction. The webs are hollow and have heating / cooling channels 362 to 367 and 371 to 377 (Fig. 4). In order to achieve a flow through the channels, these are through the Layers of the webs crossing connecting channels 380, 381, 390, 391, 392 with each other connected (see the section in Fig. 4). From each landing 301 to 306, 311 to 317 only one web 304 or 314 extends from one housing inner wall to the opposite Interior wall. All other webs have a free end.

Example 2

Figure 5 shows an alternative structure of a mixing element, as in an inventive Mixer can be used. On the heating / cooling channels along the Stege was dispensed with in favor of simple production, but they are sufficient Layers of the cross-over cooling channels 580 to 592 through the inner housing of the Mixing element.

Such a mixing element is particularly suitable for highly viscous products where the main heat resistance is on the product side and the additional one Thermal resistance due to heat conduction in the now solid webs does not ins Weight drops.

Figure 6 shows a section through the mixing element of FIG. 5 analogous to the section A-A from Figure 3b.

Claims (16)

Static mixer insert (8; 10), consisting of at least two or more layers (a) arranged side by side; (b) from each other in particular parallel webs (501, 502, 503, 504) and (511, 512, 513, 514), where the webs of adjacent layers (a); (b) from webs (501, 502, 503, 504) or (511, 512, 513, 514) and cross the webs (501, 502, 503, 504) and (511, 512, 513, 514) are connected to each other at the crossing points, characterized in that the web layers (a); (b) at the crossing points (320) of heat transfer channels (580, 581, 590, 591, 592) are crossed. Static mixer insert according to claim 1, characterized in that the Heat transfer channels (580, 581, 590, 591, 592) in individual feed lines and Discharges for a heat transfer medium open. Static mixer insert according to claim 1 or 2, characterized in that that the webs (501, 502, 503, 504) and (511, 512, 513, 514) at least partially as hollow bars (301, 302, 303, 304, 305, 306, 311, 312, 313, 314, 315, 316, 317), the additional channels (362, 363, 366, 371, 372, 373, 374, 375, 376, 377) for a heat transfer medium. Static mixer insert according to one of claims 1 to 3, characterized characterized in that the webs (501, 502, 503, 504) and (511, 512, 513, 514) are designed as straight webs. Static mixer insert according to claim 4, characterized in that the Web (501, 502, 503, 504) or (511, 512, 513, 514) to the main flow direction of the mix at an angle, in particular from 30 to 50 ° or are set from -30 to -50 °. Static mixer insert according to one of claims 1 to 5, characterized characterized in that the heat transfer channels (580, 581, 590, 591, 592) or the channels (362, 364, 365, 366) meandering at their entrances and exits are interconnected. Static mixer insert (8; 10), consisting of at least two or more layers (a) arranged side by side; (b) from each other in particular parallel webs (501, 502, 503, 504) and (511, 512, 513, 514), in particular with a rectangular cross-section, the webs being adjacent Layers (a); (b) of webs (501, 502, 503, 504) or (511, 512, 513, 514) cross and the webs (501, 502, 503, 504) and (511, 512, 513, 514) to the Junction points are interconnected, characterized in that the webs (501, 502, 503, 504) and (511, 512, 513, 514) are designed as hollow webs are the channels (362, 364, 365, 366) for a heat transfer medium. Static mixer insert according to claim 7, characterized in that the Heat transfer channels (362, 364, 365, 366) into individual supply lines and discharge lines open for a heat transfer medium. Static mixer insert according to one of claims 7 or 8, characterized characterized in that the webs (501, 502, 503, 504) and (511, 512, 513, 514) are designed as straight webs. Static mixer insert according to claim 9, characterized in that the Web (501, 502, 503, 504) or (511, 512, 513, 514) to the main flow direction of the mix at an angle, in particular from 30 to 50 ° or are set from -30 to -50 °. Static mixer insert according to one of claims 7 to 10, characterized characterized in that the heat transfer channels (362, 364, 365, 366) meandering are connected to each other at their inputs and outputs. Static mixer, consisting of at least one mixer insert (8; 10) according to one of claims 1 to 11 and an inner housing (11) which the Mixer insert (8; 10) encloses and in the openings for the supply line and discharge of the heat transfer medium to the heat transfer channels (580, 581, 590, 591, 592) or the channels (362, 364, 365, 366) are provided. Static mixer according to claim 12, characterized in that the heat transfer channels (580, 581, 590, 591, 592) or the channels (362, 364, 365, 366) are directly connected to the openings of the inner housing. Static mixer according to claim 12 or 13, characterized in that the inner housing (11) is enclosed by an additional outer housing (1) which has at least one inlet connection (4, 6) and one outlet connection (5, 7) for the heat transfer medium and with the inner housing (11) an inlet space (12) and an outlet space (13) for the heat transfer medium forms and an inlet (2) and an outlet (3) for the mix having. Static mixer according to one of claims 12 to 14, characterized in that that several mixer inserts (8, 10) one above the other in the inner housing are arranged and adjacent mixer inserts (8, 10) to each other are arranged rotated about its central axis. Static mixer according to one of claims 12 to 15, characterized in that that each web of a web position except for a maximum of one web only one end of the web ends on an inner housing wall.

Images