DD155141A1 - METHOD AND DEVICE FOR OPTIMAL IMPLEMENTATION OF CHEMICAL REACTIONS IN GRINDING MACHINES - Google Patents

Abstract

The invention relates to a method and a device for the optimal performance of chemical reactions in stirring machines. The invention relates to reactions that are only partially feasible in stirrers and for which other reactors are unsuitable. The aim of the invention is to extend the field of application of the stirring machine to such difficult to carry out reactions. For this purpose, intensive mixing of the reactants from the beginning of the filling process must be ensured. The task is solved by combining the stirrer with a specially designed mixing chamber and a solvent circuit.

Description

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Title of the invention

Method and device for the optimal performance of chemical reactions in stirring machines

Field of application of the invention

The invention relates to a method and an apparatus for carrying out chemical reactions in agitators, in which suspensions of high toughness with partly non-Newtonian behavior arise or are present, the stoichiometry constantly preserved s _; .a must and a good initial mixing is essential.

Characteristic of the known technical solutions

Depending on the application, various reactors have been developed for chemical reactions in liquid phases or in suspensions (Reaction Techniques Volume 1 and 2, Verlag Grundstoffindustrie Leipzig, 1976 »Grundriss chemischer Reaktionstechnik, Weinheim, 1958).

Basic types are the stirring machine, the loop reactor and the flow tube, each of which has characteristic residence time behavior and has its specific field of use.

In many cases, the stirring machine is used as a reactor, preferably for discontinuous reactions. she is a

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the main equipment in production plants used for the production of chemical and especially chemical-pharmaceutical intermediate and final products «

The drilling machine brings with this mode of operation some Kachteile with itself ...

- Depending on the design, a final filling volume is necessary until the existing stirring device becomes effective at all and another _? until there is sufficient stirring intensity by completely immersing the stirrer and the flow disturbers © '...''.

- The limited Wärmeaustauschflächea _s connected to the often insufficient, especially in tough media stirring action, führen.zu long inlet · »and response times in exothermic Prozessenο

The agitators are therefore particularly unsuitable for reactions in which - - ..

- an intensive mixing of the reactants from the beginning is necessary, .. '>.

- the reactants must constantly be in a constant stoichiometric ratio,

- The feed of the reactants must be carried out at the reaction temperature,. .., .., ', ..

- high reaction rates and exothermic,

- Under these conditions additionally a suspension of high toughness was present.

Object of the invention

The aim of the invention is to extend the field of application of the standard batch stirrer to such reaction conditions which hitherto can not be controlled in stirrers and which are usually very difficult to realize even in continuous reactors

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Explanation of the essence of the invention

The invention has for its object to provide a stirred reactor and a method of working with this., Which reactions, in particular of nieht ~ newtonseben liquids and suspensions are allowed, requiring intensive mixing over the entire reaction period, a constant stoichiometric ratio of Reaction partners require high reaction rates and increased heat of reaction »

The object is achieved by the stirrer is combined with a specially designed mixing chamber. · ...... The mixing chamber according to the invention consists of a Hohlzyiinder with a Riihrwelle, on which a plurality of stirring elements of the same or different types are attached. Preferably, paddle stirrers are used for this purpose. The hollow cylinder is provided with a multi-partitioned double jacket, which allows both the heat of reaction by heat transfer and by the reactants themselves on and off »This makes it possible that the reactants enter the reactor at reaction temperature, without any loss of Heat exchange capacity occurs. It is also possible for this purpose that the reactants flow via Reaktandenzufuhrungen, which may be formed as dip tubes, to the mixing point. These installations then serve as baffles. The mixing chamber is designed so that it can be placed on the mixer or immediately next to it. It is also possible, instead of a stirring machine, another suitable apparatus, for. B. a Riihrkesselkaskade or column to react to use · An outlet is used to remove the goods.

According to the invention, the reactants pass after passing

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a Semperierzone in which they ζ _β B * by reaction heat brought to reaction temperature v / earth, in a mixing zone. There, an intensive and rapid mixing of the components and the beginning of the reaction takes place. * The reaction mass leaves the mixing chamber after a short dwell time via the outlet j without being fully reacted. «

By far the greater part of the reaction time is realized in the agitator into which the reaction mass is already mixed homogeneously. The agitator is filled continuously via the mixing chamber. After the filling, the reaction is terminated by the corresponding residence time in the stirrer

It is virtually impossible to convey a non-Newtonian, unreacted suspension through a pipeline, as due to different flow velocities across the cross section, the suspension is not evenly reacted and the solid produced by the reaction quickly adds the line Metering and mixing preferably in the lower part of the mixing chamber to make and release the unfinished reaction product at the top in free fall into the mixer «" The free jet guarantees a uniform velocity profile over the cross sections He may be surrounded by a protective tube »Furthermore, the pipe is provided to be kept free by a partially internal solvent circuit by distilling off a part of the solvent from the stirring machine and returning it again via the condenser and pipe.

embodiment

The invention will be explained in more detail below using an exemplary embodiment

 In the accompanying drawings show:

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FIG. 1: the mixing chamber,

Figure 2: the mixing chamber with downstream stirring machine.

Figure 1 shows the senematic structure of the mixing chamber · The nozzles A and B are the lines for the supply of the components «The double jackets 1 and 2 are used to. or * dissipation of heat of reaction to varying degrees »By the stirrer shaft 3» equipped with paddle stirrers ·, the.-reactants are in the. Ho hl cylinder 8 intense and

quickly mixed together « -

The reaction mixture leaves the mixing chamber via the outlet 4. The sealing of the stirring shaft 3 takes place through the stuffing box fj>. Position 6 is the drive of the stirrer shaft 3, which is mounted in 6 and the bearing 7 «

Figure 2 shows the procedure for an optimal implementation of chemical reactions in .Mührmaschinen * The components flow in the lines A and B through the mixing chamber 11 · They are thereby tempered to reaction temperature. At its exit point at the lower end of the mixing chamber 11 there is an immediate and intensive mixing of the components. The reaction temperature is ensured by the double jackets 1 and 2. By conveying the material flows, the mixture passes under constant agitation to the outlet 4 at the upper end of the mixing chamber 11. About the outlet 4, the mixture comes in free fall in the stirring machine 9 · Here, the post-reaction takes place. ,

To prevent clogging of the spout 4, the line is kept free via an internal solvent circuit 10.

Claims (1)

-6 » Z 2 5 9 2 2 Erfindungsansprach 1 _e Process for the optimal performance of chemical. Reactions in agitators _f, characterized in that the reactants brought to Eeaktionemperatur, intensively • mixed and as unreacted Eeaktionsgemisch from the mixing chamber (11) in free fall on the upper end of the outlet (4 ·), which via an inner solvent circuit (10 ) is released, are released into the agitator (9) * 2 <* Method according to item 1, characterized in that the reactants are dosed by means of dip tubes in the lower part of the mixing chamber (11) and mixed γ / ground. Process according to item 1, characterized in that the heat of reaction is removed both by heat carriers and by the reactants via the subdivided double jacket (1, 2) to and .beta 4 Apparatus for carrying out the method according to item 1, characterized in that a mixing machine (9) comprises a mixing chamber (11) consisting of a hollow cylinder (8) with a ring-shaped, multiply divided double jacket (1, 2), a centrally arranged Stirring shaft (3) with stirring elements, a Reaktandenzuführung (A, B), which is optionally formed as a dip tube and an outlet (4 ·) with optionally subsequent protective tube, and a solvent circuit (10) are arranged upstream. 5 · Device according to item 4-, characterized in that the stirring elements are paddle stirrers. - 7 - 2 2 5 9 2 2 6. Device according to item 4, characterized in that the mixing chamber (11) is constructed directly on the stirring machine (9). 7 «device according to item 4-, characterized in that the Biihrniaschine (9) is a Eiihrkesselkaskade or column. · · For this 1 page drawings