DD140206A1 - STAGE REACTOR FOR CARRYING OUT CHEMICAL AND / OR PHYSICAL OPERATIONS AND ITS APPLICATION - Google Patents

Abstract

The invention describes a step reactor for continuous Conducting chemical and / or physical operations fluid Phases, for reasons of reaction rate, the heat of reaction and the backmixing suitably carried out in several stages become. The reactor should have a high throughput, based on the Apparatus volume and the unit of time, have. It consists of several in an apparatus vertically stacked steps through a common, similar to the height of the stages divided stirrer shaft and at this arranged for each stage concentric stirring elements mixed and through the double-walled boundaries of the steps optionally cooled or heated. The invention is preferably used in the converting industry.

Description

VEB CHEMICALS BITTERFEID Bitterfeld, Nov. 24, 1978

1984 ',

Step reactor for performing chemical and / or physical operations and its application

Applicability of the invention

The invention relates to a step reactor for the continuous implementation of chemical and / or physical reactions or operations of fluid phases and its application for various methods.

Characteristic of the known technical solutions

It. It is known that reactions or operations in the liquid phase, which correspond to the reaction rate, the backmixing, the heat of reaction u. In continuous mode, parameters run in several stages, frequently. in a so-called reactor cascade, d. H. in a succession of several agitator apparatuses "

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In the individual agitators a quasi-complete Rückverini research of reactants is achieved by stirrers of different shape and speed,

Reactor cascades require a considerable construction volume (in particular floor space requirement, Stahlbaukonstruktiön etc.). The connection of the individual agitator / tank by means of pipes creates an uncontrolled heat transfer, the risk of leaking compounds, which is particularly important for hazardous substances, and a high investment and installation costs.

The summary of the separately operating agitator container to an apparatus leads z. B. to the so-called cell reactor (DD-PS 103 390).

In this flow through the mutually reactive liquid reactants formed in a horizontal cylindrical vessel by means of circular section internals cells in succession. At the same time, the components are mixed with each other by disks sitting on the horizontal drum and submerged in the cells.

 The positive or negative reaction enthalpy occurring in the reactions requires an increase or decrease of heat through corresponding heat exchange surfaces, which may be formed as a double jacket or welded solid or half tubes.

With the summary of the reaction cascade to the cell reactor, the deficiencies of the usual agitator cascade are largely eliminated, but the specific, d. H. the heat exchange surface related to the reaction volume is decisively reduced since the horizontal arrangement of the reactor means that its cross-section can only be utilized up to the overflow edge of the circular-section-like internals.

The heat transfer can therefore be made only by the liquid-wetted part of the cylindrical jacket.

The horizontal design of the cell reactor and its imperfect volume utilization lead to long asymmetrically loaded stirrer shafts whose deflection requires special design measures.

It is also the combination of several cascade stages to an apparatus known in which in a plurality of superimposed by cylindrical parabolic staggered constrictions interconnected inlets can be constructed by arranged on a common rotating shaft conical rings with plunging into the annular chambers liquid rings, depending on This arrangement, like the so-called cell reactor, permits the stepwise separate supply or removal of heat, but, despite a relatively better utilization of the exchange surfaces, has one for many applications low heat exchange capacity, especially at low speeds of the stirring element, since then the outer shell, which is the only heat exchange surface, is only partially wetted. Due to its Korftruktion the apparatus is useful only for rapid reactions and can be used only within narrow limits in terms of loading, throughput and average residence time. Sr also has the disadvantage of not being designed according to the modular principle and requires a high manufacturing complexity because of the complicated contours of the outer shell.

Another vertical summary of several separate reaction spaces is described in DD-PS 66 616. In this apparatus, the reaction components are replaced by

The internals according to the principle of the thin-film evaporator are centrifuged separately from one another onto the inner surface of a cylinder serving for the heat exchange and run together under the action of gravity to the next stage.

In terms of reaction technology and hydrodynamics, the construction has many similarities with the apparatus according to OE-OS 1 442 735. Again, the residence time can only be varied within very narrow limits and given the effective heat exchange surface only through the outer cylinder. Furthermore, also applies to this construction, that it is very expensive to manufacture.

Both constructions are unsuitable for reactions with a longer required residence time.

Also in several stages in a vertical arrangement is proposed in DD-PS 57 108 device for the continuous implementation of chemical reaction processes. Although not explicitly stated, this apparatus is undoubtedly heatable or coolable on the outer jacket. The puncture of the apparatus is based on a reliable acting seal the rotating downwardly open sectors relative to the fixed base plate and optionally the cylindrical outer shell. Although any residence times can be achieved in this device, such an apparatus is unsuitable for corrosive and / or erosive substance systems.

In DE-AS 1 028 539 an apparatus for the continuous implementation of chemical and physical processes is described. It consists of a stirrer, which orders from concentric tubes, which engage in the annular spaces of a likewise formed from concentric tubes stator * The walls of the stator can be double-walled as heating or cooling surfaces.

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This construction has the disadvantage that reactions under gas evolution can only be carried out to a limited extent, since only the overflow zone, which is small in relation to the reactor volume, between two annular spaces is available for safe degassing.

Another serious disadvantage of this single-stage construction lies in the closely adjacent arrangement of the heat exchange surfaces, which does not permit a clearly definable temperature control of individual reaction phases.

Object of the invention

The intensification of the production equipment requires the increase of the equipment throughput in relation to the volume of the apparatus and the time unit.

At the same time, the safety of the operation should be increased by stable management of the reaction and improvement of the reparability of the apparatus. The apparatus should be easily adaptable to different reaction systems. '

The. Invention is based on the object of combining any number of stages for performing chemical and / or physical operations in an apparatus. Furthermore, for safety reasons, the reactor content is to be reduced and the specific heat transfer area related to the reaction mass and the throughput related to the apparatus volume to be increased. The apparatus should be easy to adapt to various processes by means of modular elements. Easy assembly / disassembly must guarantee good cleaning and repairability «

By using in the form and / or speed of different stirrers, the flow of the fluid phases should be influenced.

Explanation of the essence of the invention

It has been found that by vertically stacking any number of individual stirrer stages 1, Pig. 1, in an apparatus using a common analogous to the height of the stages divided stirrer shaft 2 can receive a variable stages reactor corresponding to the established requirements.

The individual stages consist of a cylindrical outer boundary 3 of the reaction space 23 and a concentrically arranged, formed as a cylinder tube coil 4. Thus, in the interior of the reactor stage, a heating or cooling is possible. Both cylinders are interconnected by a circular bottom. In the vessel thus formed immersed also a concentric, rotationally symmetrical.es stirring and / or conveying member 6 a. This is attached to the common stirring shaft 2. The lateral boundary of the individual. Steps is designed as a double wall 7, and thus each stage can also be heated or cooled from the outside. The individual Y / armeübertragungsstufen can also be switched recuperatively. By forming a plurality of concentrically intermeshing rotor, or can be heated or cooled stator rings can be realized in each stage a plurality of successively flow-through annular reaction chambers 23.

The individual stages are connected by flanges 8 in the usual manner in apparatus construction.

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The inner cylinder 4 of the reactor stage also serves as an overflow of the liquid phase in the next stage. Due to its special design, this overflow 9 ensures uniform liquid distribution, so that the overflowing liquid is again cooled or heated in a falling film zone 24 between the stages. Optionally formed in the reaction gaseous products are deposited and guided by the free cross section of the inner cylinder 4 upwards. The gases leave through the sufficiently sized gas discharge openings 10 in the stirring and / or conveying member 6 and through the nozzle 11 the apparatus. The nozzle '12 allow the supply and the nozzle 13, the removal of the components in or, from the individual stages .. Through port 14, the reaction mixture leaves the final stage of the device. The compound 21 of the stirring and / or conveying member 6 with the shaft 2 is formed so that. by exchanging the same for such another suitable form of the step reactor is fluidly adaptable to various reaction conditions. Fig. 2 shows a possible embodiment, which works largely without backmixing of the reactants. By contrast, FIG. 3 shows a stirrer shape which achieves a very large backmixing. The heat transfer system 7 of the individual stages enables optional independent heating or cooling of each individual stage, so that the required temperature profile is easy to manufacture. Optionally, the reaction partners in the upper stages can be preheated to the required reaction temperature with the heat of reaction liberated (recuperative procedure).

In the case of strongly exothermic reactions, the thermal behavior of the reactor can also be influenced by the stepwise metering of reaction components.

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At the cylinder 3, a nozzle 15 is mounted for measuring temperatures. The agitator shaft 2 has at the upper part of the reactor outside the WeIIenabdichtung and below the reactor bearings 16 and 17. The shaft seal 18 must be formed according to the required pressures in the reactor and the corrosion stresses. Any construction customary in apparatus construction can be used.

The agitator shaft 2 is rotated by a preferably continuously variable speed drive 19 in turns. The formation of the shaft connection 20 between the individual stages ensures rapid and accurate assembly as well as the release of the compounds even after corrosive attack of the material (Fig. 4). ··

By varying the mass flow supplied through port 12, the desired residence time in the reactor can be set to a value determined by the flow resistance of the interior of the reactor.

The construction of the device makes it possible to perform all chemical and physical operations that take place in the fluid state, ie. H. also reactions in heterogeneous solid-liquid, gaseous-liquid or gaseous-solid-liquid mixtures. Of course, it is also possible to carry out processes under a protective gas atmosphere. Furthermore, it is possible to supply pesticides through the nozzle 22 and optionally zu.dispergieren, dissolve or melt * The construction allows the production of the reactor of all conventional apparatus materials, such as metal, glass, plastics, Grafitwerkstoffen and optionally. Material combinations.

The materials used and the dimensioning of the components allow the system pressure and temperature to be adapted to practically all requirements. , '_'.

•. r -

pig. 1 shows a vertical section through a preferred embodiment of the step reactor,

FIG. 2 illustrates the arrangement of the gas discharge openings on a possible embodiment of the stirring and / or conveying element,.

pig. 3 shows a further design possibility of the stirring and / or conveying member,

Pig. 4 shows the formation of the shaft connection between the individual stages.

The following examples describe the execution of some special processes in the step reactor according to the invention, without restricting its fields of application,

Example yy

Reaction of 4-nitrotoluene with 28er oleum

It is a reactor gem. Pig. 1 with 5 stages used «The reaction volume of the individual stages is 34.5 1 · The stages are equipped with agitators 6 acc. Pig. 2 equipped. All stages are provided with a temperature control at 15. The number of revolutions of the stirring shaft 2 is 40 rpm. In the reactor 182.7 parts by weight / h of 4-lTitrotoluol be reacted with 437.5 parts by weight / h 28er oleum. The mean residence time is 26 minutes, too. Beginning in the first stage, 36.5 parts by weight of 28 oleum over the nozzle 12 in the first. Stage fed. Filling the drive 19 are also fed via a nozzle 12 15.25 parts by weight of 4 * ~ nitrotoluene in the reactor. It is ensured by supply of cooling liquid according to 4 and 7 that the temperature measured at '15 80 ⁰ C does not exceed. Thereafter, it is switched to continuous operation. For this purpose, 127.9 parts by weight / h of 4-Witrotolnol of .70 ⁰ C and 437.5 parts by weight / h of oleum 28 via the nozzles 12 at the same time

from room temperature to the first stage. After about 5 minutes, the addition of a further 54.8 parts by weight / h of 4-nitrotoluene at 12 to the second stage of the reactor is begun.

Via the temperature measuring devices attached at 15, the supply of cooling or heating means according to 4 and 7 in the individual stages is regulated so that the following temperature regime is set:

• "Level 1: 85 - 90 ⁰ C Level 2: 90 - 95 ⁰ C Levels 3-5: 95-98 ⁰ C

This gives 620 parts by weight / h of reaction mixture with a share of 286.5 parts by weight of 4-Nitrotolüol-2-sulfonic acid. This corresponds to a degree of conversion of 99 % of theory, based on 4-nitrotoluene ·

The reaction mixture leaves the reactor via the nozzle of the 5-stage and is fed from there to the v / eere workup.

Example 2:

Reaction of 1 ~ nitro-4 * -chlorobenzene with oleum 65 in the presence of H ₂ SO.

It is a reactor gem. Pig. 1 with 3 stages used «Step size, stirrer shape and rotation as well as temperature monitoring correspond to example 1.

In the first stage of the reactor are at 12 at the same time 45.6 parts by weight / h of H ₂ SO ₄ (96 #ig) of 25 ⁰ C, 48.4 parts by weight / h of 1 ~ nitro-4-chlorbeiizol of 115 ⁰ C and 67.9 parts by weight / h 65er oleum of 25 ⁰ C fed.

With the aid of the temperature measurement at 15, the supply of heating or * cooling medium according to 4 and 7 is controlled so that adjusts the following temperature profile in the reactor:

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Stage 1: 128 - 130 ⁰ C

Stage 2: 130 - 132 ⁰ C

Stage 3: 132 - 135 ⁰ C

Via the nozzle 14 of the third stage, the sulfonation mixture is fed to the workup. It contains 72 parts by weight / h. 1 ~ ~ Uitro 4-chlorobenzene-2-sulfonic acid ~. This corresponds to a degree of conversion of 99 $ of theory, based on 1-Kitro-4-ehlorbenzol.

Example 3:

Reaction of acetanilide with chlorosulfonic acid

A 3-stage reactor according to Example 1 is used. 67.5 parts by weight / h of N-acetylaniline are introduced via a rotary valve at the connection 22 into the first reactor stage filled with 30 parts by weight of chlorosulfonic acid before the beginning of the reaction. At the same time 262 parts by weight / h of chlorosulfonic acid are fed at 12 in step 1. The hydrogen chloride formed, which is released particularly intensively in the film zone 24, leaves the reactor via the gas discharge openings 10 in the neck 11. The reaction is exothermic in its first stage (sulfonation) and endothermic in the second stage (sulfochloride addition) . ' For this reason, the first stage is cooled, the two following heated, however. The reaction temperature in stage 1 should be 40 - 50 ⁰ C, in the following stages is carried out at 80 90 ⁰ C. ·

About den.Stutzen 14 leaving 311.4 parts by weight / h Chlorsulfoniergemisch the reactor with a content of 93 parts by weight / h N-acetylamino-benzenesulfonyl chloride * This corresponds to a yield of 79.5 % of theory, based on E At the same time, 11 18 parts by weight / h of hydrogen chloride are supplied to the absorption via the connecting piece.

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Example 4:

Chlorination of vinyl acetate

It is a reactor gem. Fig. 1 with a stirrer gem. Fig. 3 used. There are 6 similar reactor stages used. The rotational speed of the rotor shaft 2 is 60 rpm, the reaction temperature should not exceed ⁰ ° C. "With the aid of the temperature measuring devices attached at 15, the admission of the tube coils 4 and the cooling jacket 7 is controlled with cooling brine. In the first stage of the reactor be fed at 12 258 parts by weight / h of vinyl acetate and pre-cooled to - 5 to - 10 ⁰ C. Through the nozzle 12 of the second stage 106.5 parts by weight of chlorine / h are introduced after about 8 minutes. After another 4 minutes you start with the introduction of another 64 G-ew.-parts chlorine / h in the neck 12 of the third stage. 25 minutes after the beginning of the supply of vinyl acetate in the 1st stage, 42.5 parts by weight of chlorine / h are fed through the nozzle 12 of the 5 "stage. About the nozzle 14 of the 6th stage leave 468 parts by weight of dichloroethyl / h the reactor. The degree of conversion is 99.4 iö. Unbound chlorine is removed via the pipe 11.

Example 5:

Nitration of chlorobenzene

It is a reactor gem. Pig, 1 used. Step number and size as well as rotor shape and revolution number correspond to example 1. In the first reactor stage, at the same time 132.6 parts by weight / h chlorobenzene and 115.2 parts by weight / h mixed acid (consisting of 38 % HFOo, 52 % H ₂ SO, and 10 fo HpO). Approximately 10 minutes after the start of the reaction, 12 additional 76.8 parts by weight / h of mixed acid are added to the second stage at 12. With the help of the temperature monitoring installed at 15, the following reaction temperatures are realized in the individual stages;

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step 1: 45 - 50 ⁰ C step 2: 50 - 55 ⁰ C step 3: 60 ⁰ C step 4: 65 ⁰ C step 5: 70 ⁰ C

Per hour, leave the reactor at 14 324 parts by weight of nitration mixture with a share of 169.8 parts by weight of nitrochlorobenzenes (ratio ortho: para: meta = 34.6: 64.5: 0.9). The liberated during the reaction nitrous gases are fed through the nozzle 11 of the absorption.

The technical and the technical-economic effects of the invention:

Due to the vertical arrangement of the stages is an optimal utilization of the apparatus walls to. achieved heat transfer. At the same time, the throughput, which is related to the volume of the apparatus, can be considerably increased by the large specific heat exchange surface in reactions with high heat of reaction.

Claims (3)

Inven tion sanspruc h. Step reactor for the continuous performance of chemical and / or.physikalischer operations fluid phases, characterized in that a plurality of similar with multiple nozzles for produktzu- (12) or -abführung (13, 14) and / or for measuring purposes (15) provided heatable or coolable cylindrical, possibly by concentric partitions (4) divided into several reaction chambers stages (1) are vertically arranged one above the other like a box, in the reaction chambers (23) concentrically from above agitating and / or conveying members (6) engage, on a common, analog the height of the stages divided stirrer shaft (2) sit, and a 3? Allfilmzone (24) for temperature regulation and degassing of the reaction mass after flowing through the reaction space have. Step reactor according to item 1, characterized in that the boundaries of the individual stages are designed as double walls (7) which serve for heat transfer, and each stage can also be recuperated, heated or cooled independently of the adjacent ones. - '- 15 -20 9 45 4 1984 3-stage reactor according to item 1 and 2, characterized in that the specific heat exchange surface is increased by incorporating v / eerer concentric double walls (4) in the individual stages. · Step reactor according to item 1, characterized in that by appropriate design of the concentric stirring and / or conveying member (6) and by variable-speed drive (19) quasi any flow shape and any mixing sgrad can be achieved. 5 stage reactor according to item 1, characterized in that the residence time can be adjusted to an arbitrary value by changing the supplied Masse.stromes. 6. stage reactor according to item 1 to 5, characterized in that this also supplied to pesticides and optionally dispersed, dissolved or melted. 7. stage reactor according to item 1 to 5 », characterized in that can be carried out in this chemical and / or physical operations that proceed in a fluid state, even in heterogeneous solid-liquid, gas-liquid or gaseous solid-liquid mixtures. 8. stage reactor according to item 1, characterized in that it can be produced from all metallic materials, glass, plastics, graphite and optionally material combinations. 9 * stage reactor according to item 1, characterized in that it can be operated depending on the design and requirement also at vacuum or higher pressures and different temperatures. - 16 -it U ν ** 2 ^ 1984 1O. Process for the continuous performance of chemical processes in a stage reactor according to items 1 to 9, characterized in that a liquid under the process conditions component with one or more other components, which may be liquid, solid or gaseous, is treated in fluid phase, wherein arise liquid and / or gaseous end products, For this. ^ .... ropes drawings