GB1580826A - Reaction vessel - Google Patents

Abstract

A base vessel (1) having a predefined design and a likewise predefined cascade attachment (3, 21) are assembled, by means of a flange connection (12), to form a reaction vessel. By connecting a plurality of such reaction vessels in series, reaction cascades for carrying out multi-step chemical reactions proceeding continuously can be assembled as required. The base vessel (1) contains agitator appliances (8-10), while the cascade attachment (3, 21) is provided with product inflow and outflow arrangements (13, 14, 17, 19). Depending on the specific cascade attachment (3, 21) being used, the reaction vessel can be fashioned as an open or as a closed vessel. The fitting and energy connection elements (11, 12, 18) and the product inflow and outflow arrangements (13, 14, 17, 19) at the vessel parts (1, 3, 21) are designed in such a way that the reaction vessels can be mounted directly onto stationary support arrangements having fixed connection elements. <IMAGE>

Description

(54) A REACTION VESSEL (71) We, VEB ARZNEIMITTEL WERK DRESDEN, of 35, W,Fshelm-Pieck- Strasse, 8122 Radebeul, German Democratic Republic, a Corporation organised under the laws of the German Democratic Republic, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to a cascade-type reaction vessel for selective use as an open top or closed top vessel for multiple-stage chemical reactions which take place continuously, possibly highly exothermically.

This invention is concerned with a reaction vessel having standardised dimensions for chemical reactions which occur pressurelessly, but possibly highly exothermically, in homogeneous or heterogeneous phase, and also to the arrangement of a plurality of such vessels on the cascade principle for multiple-stage chemical reactions.

German Democratic Republic Patent Specification 94 606 describes a reaction vessel having easily exchangeable fittings for continuous multiple-stage chemical reactions occurring more particularly in suspensions with highly fluctuating consistence of the reactants.

The simple adaptation of the vessel fittings to the consistence of the particular reactants for multiple-stage chemical reactions described in said Patent Specification can only ever relate to the liquid or suspended phase because of the design considerations explained in said specification. At higher operating temperatures which may lead to the partial evaporation of a solvent used, it is necessary to fit individual cooling devices in order to condense the res- pective solvent vapours. Similar problems of apparatus are encountered when gaseous reaction products occur. In both cases, this fact leads to the installation of units which are not co-ordinated with the reaction vessel according to said specification and exclude a rational mode of use in the reactor cascade.

It is an object of the invention, without modification to the reactants and energy supply means necessary for multiple-stage chemical reactions, to construct the vessel for assembly and disassembly on the buildingblock unit principle, whilst fixed physical conditions constant for auxiliary elements of the apparatus. The vessel is particularly intended to be arranged in any desired number to form a reactor cascade and to be used predominantly for continuous reactions, possibly taking place highly exothem:ically, in which solvent vapours are condensed or harmful gases absorbed in some sections, but manual intervention with the reactive mixture is necessary in other sections. The manual interventions may include, for example elimination of crusts, exchange or cleaning of measuring electrodes or continuous sampling.

The present invention, whilst retaining all the advantages of the easily exchangeable fittings, broadens the universal scope of use fulness of the reaction vessel according to the above mentioned specification to include also the stem space above the liquid level by the selective assembly and reassembly of standardised fittings with different possibilities od use on to a vessel base part whilst maintaining fixed connections constant.

The combinable cascade reaction vessel assemblably and disasseblably on the buildingblock unit principle for selective use as an open top or closed top vessel for multiplestage chemical reactions taking place continuously, possibly high exothermically, is achieved according to the invention in that the combination is constituted by a vessel base part and either a closed top part connectible to the base part and having at least one inlet connecter for rhe reactants and at least one weir outlet connecter for the reaction products located below said inlet connecter, said top part including measuring, gas or vapour outlet connectors, or an open top part connectible to the base part and having an outlet duct of semi-cylindrical cross-section, the connection between the vessel base part and the open or closed top part being constructed as a flange joint.

The dimensions of the open or of the closed cascade top part are so determined that no modifications arise for any of the fixed points of energy and reactant pipes or conductors when exchanging the open or closed cascade top part.

Where a plurality of the vessels according to the invention are arranged to form a reactor cascade, its length and height difference between inlet and outlet is not modified by the partial or total exchange of the open or closed cascade top parts on the indivdual vessels.

Standard coolers for solvent vapours or flue and sorption devices for vapours or gases can selectively be attached to the gas or vapour outlet connections of the closed cascade top part.

By virtue of the favourable ratio of reactor volume and free crossffection of the discharge pipes, and of the possibilities of intensive cooling, the vessels in the combination of vessel base part and closed cascade top part are suitable for reactions which occur highly exothermically with spontaneous evolution of gas, such as nitriding or halogenating processes.

The combination of vessel base part and open cascade top' part finds application par ticularly where manual interventions in the reaction process are constantly necessary.

The cascade arrangement of the vessels according to the invention represent the optimum technical process variant compared to conventional reaction apparatuses for multiple-stage chemical reactions with different physico-chemical behaviour of the individual stages.

The capacity of the reaction vessel of the invention is 20 to 500 1, preterably 50 to 100 1, the ratio of diameter: overflow height is 0.8 to 1.2 : 1.

The principal advantage of the reaction, vessels is to be seen in the fact that any desired number of vessels which are arranged ro foom a cascade and are provided with stationary energy and reactants supply means together with support and bearing elements, can be used selectively for different basic processes and basic operations whilst main taining the stationary connections. Particularly in continuously operating multiple-purpose plants for chemical or chemical-p harm aceutical products with low tonnage, a change of the reagents and of the reaction conditions frequently occurs. As is shown by the exemplary embodiment, the universally useful reaction vessel can be exchanged as an open or closed variant within the cascade arrangement or be connected together. Since in both embodiments the vessel base part with its energy connections and support elements is unchanged, and the outlet channel to the next vessel and the chemical inlet can likewise remain stationary irrespectively of the variant of the vessel, the reactants inlet and reactants outlet of a reactor cascade thus remain constant.

This exchangeability with constant overall dimensions of the apparatus is achieved technically by the following arrangement of the individual elements: The height difference between top edge of vessel base part and damping sleeve wedge bearing ob the open embodiment is identical with the height difference between top edge of vessel base part and the bearing bushing of the closed embodiment. Thus, irrespectively of the embodiment, the position and length d the agitator including the coupling point between agitator drive and agitator shaft remains constant.

Constant inclinations of outlet channel of the open and outlet pipe of the closed em- bodiment with constancy of the overall dimen sions d the apparatus are further common dimensions of indivdual elements. The vessel base part which is always present, irrespectively of the open or closed embodiment, has the stationary feed means for steam and cooling water, which require no modification.

The construction of the reactor cascade is thus bounded in its overall dimensions in one plane by a right-angled triangle, the hy potenuse of which fixes the connection points of rhe agitator drive and its acute angle the reagent charging and/or product discharging.

Within these limits the selective exchange of the indivdual vessels is effected geometrically by elements, the boundary of which is like wise given by a right-angled triangle. The vertical difference between rhe top edge of the vessel base part and the agitator drive forms the one, and the difference in length between the lateral edge of the vessel base part and the end of the outlet pipe or outlet channel forms the other short side. The hypotenuse touches the coupling point be tween agitator shaft and drive. Thus the selective exchange of the components of the apparatus can be characterised geometrically by fixed points of right-angied triangles, while the sum of these geometrically and physically identical exchange elements does not exceed the prescribed spatial limits of the cascade.

This phenomenon is extremely important, because reactor cascades are generally charged by stationary transport or dosing devices and the reaction product is isolated by likewise stationary mounted separator devices, and thus an existing utilization of space of a production area is present.

The exehaneability of the vessel elements in conformity with the particular specific con ditions cannot be deduced from the prior art of chemical process technology. The possibility according to the invention of arranging open and closed top vessels one after another for the optimum apparatus condition and rhe most favourable manual intervention with the process cycle of an existing multiple-stage chemical reaction are possible only by break ing-donvn the product stream into a plurality of theoretically stationary reaction regions, which can be formed in optimum manner, for example by a series of open or closed top vessels as thermically, hydrodynamically or chemically different components of the cascade arrangement in an optimum manner.

Such a physical-chemical optimisation in partial stages of a chemical reaction, which can be effected in a manually simple manner, by selective demarcation of different regions within a product stream can only be performed by the selective exchange of the top vessel elements according to the invention and, in the case of conventional agitator reactor cascades, only by exchanging the entire unit.

The advantages of the invention which have been mentioned can therefore be achieved only with the combinable vessel described.

In such a cascade arrangement, as complared with the possibilities of the previously mentioned patent specification, special reactions can be performed, such as substitution reactions, reductions, alkylations, halogenations, nitrifications, can take place even with different solvents in the boiling range thereof with full utilization of the advantages of the continuous reaction oontrol.

Particularly for reactions which are highly exothermic or involve spontaneous evolurion of gas, the favourable ratio of the free crosssection of the gas outlet pipe or cooling surfaces with respect to the reaction vessel which is used is extraordinarily important from technical safety standpoints.

In order that the invention may be more readily understood, reference is made to the accompanying drawings which illustrate dia grainmatically and by way of example embodiments thereof, and in which: Wig. 1 shows a vessel base part viewed in section on 'the line A - B of Fig. 4, with double wall, IFig. 2 shows a vessel base part with a single wall viewed in section on the line C - D of Fig. 5, Fig. 3 shows an open cascade top part for aqueous suspension reactions viewed in section on the line E - F of Fig. 6, Fig. 4 shows a section on the line G - of Fig. 1, Fig. 5 shows a section on the line I - K of Fig. 2, Fig. 6 shows a section on the line L - M of Fig. 3, Fig. 7 shows a closed cascade top part for toxic reactions viewed in section on the line N -- O of Fig. 8, Fig. 8 shows a section on line R - S of Fig. 7, and Fig. 9 shows an arrangement of a plurality of reaction vessels using different components.

Figures 1, 4 and 2, 5 respectively show the essential details of the construction of two kinds of the vessel base parts 1, 2. The base vessel part 1 having a double wall 4 is made of steel and is enamelled. The internally located bracket plates 7 serve to fix a partition wall 5 which has bottom clearance.

A bearing block 8 serves to receive a geared motor (not shown) and to mount an agitator 9 by means of clamping bearings 10. The heating or cooling of the contents of the reaction vessel is effected through the double wall 4, an inlet connection 15 being fitted tangentially to the wall 4. Straps 11 made of steel are provided for mounting the vessel.

For reactions without supply or dissipation of thermal energy, a vessel base part 2 is provided which is made of compounded material, for example polyvinyichloride with polyester laminate. It may alternatively be manufactured of steel or special steels without the use of special tools. The internal and external fixtures correspond to the vessel base part according to Fig. 1. In Figs. 2 and 5 the partition wall 6 is constructed as a cooling pocket. The construction to form a reaction vessel is effected with the cascade top parts or headpieces according to Figs. 3, 6, 7 and 8. The open cascade top part 3 with an outlet duct 13 of semi-cylindrical cross-section is made of special steels. The fixed joint to the base part 1 or 2 is made by means of a flanged ring 12. Sealing is effected with a PTFE-seal element. The outlet duct 13 serves for the continuous outlet of the contents into the next reaction vessel and by means of a flange 14 the headpiece 3 can be firmly connected to a closed cascade top part 21 for toxic reactions as shown in Figs. 7 and 8.

This closed cascade top part 21 is used with the vessel base part 1 or 2 when reactions with readily boiling substances, highly exothermic reactions or reactions with cleavage of toxic gases are carried out.

The continuous supply of the reactants is effected via the inlet connecter 17 which ter minutes below the surface of the liquid level in the reaction vessel and thus forms a gas lock. The outlet duct in the case of this top part is constructed as an outlet connecter 19.

The gas-tight sealing lof the agitator 9 iso effected by a simmer ring in the bearing bush 18, because in this case the clamping sleeve bearing 10 is dispensed with and the mounting of the agitator is effected by a ball-bearing in the bearing bush 18. The inserted pipe connections 16 are provided for the erection of reflux coolers or for fixed connecting pipes of toxic substance destruction plant. The smaller connections 20 serve for pH measurement, temperature monitoring and for dosing reaction substances.

All the components are made in such a way that any desired variants adapted to the par ticular production process are possible, as is shown, for example in Fig. 9.

WHAT WE CLAIM IS:- 1. A reaction vessel for selective use as an open top or closed top vessel, comprising in combination a vessel base part and either a closed top part connectible to the base part and having at least one inlet connecter for the reactants and at least one weir outlet conneoter for the reaction products located

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (5)

1. **WARNING** start of CLMS field may overlap end of DESC **.

   Such a physical-chemical optimisation in partial stages of a chemical reaction, which can be effected in a manually simple manner, by selective demarcation of different regions within a product stream can only be performed by the selective exchange of the top vessel elements according to the invention and, in the case of conventional agitator reactor cascades, only by exchanging the entire unit.

   The advantages of the invention which have been mentioned can therefore be achieved only with the combinable vessel described.

   In such a cascade arrangement, as complared with the possibilities of the previously mentioned patent specification, special reactions can be performed, such as substitution reactions, reductions, alkylations, halogenations, nitrifications, can take place even with different solvents in the boiling range thereof with full utilization of the advantages of the continuous reaction oontrol.

   Particularly for reactions which are highly exothermic or involve spontaneous evolurion of gas, the favourable ratio of the free crosssection of the gas outlet pipe or cooling surfaces with respect to the reaction vessel which is used is extraordinarily important from technical safety standpoints.

   In order that the invention may be more readily understood, reference is made to the accompanying drawings which illustrate dia grainmatically and by way of example embodiments thereof, and in which: Wig. 1 shows a vessel base part viewed in section on 'the line A - B of Fig. 4, with double wall, IFig.
2. 2 shows a vessel base part with a single wall viewed in section on the line C - D of Fig. 5, Fig. 3 shows an open cascade top part for aqueous suspension reactions viewed in section on the line E - F of Fig. 6, Fig. 4 shows a section on the line G - of Fig. 1, Fig. 5 shows a section on the line I - K of Fig. 2, Fig. 6 shows a section on the line L - M of Fig. 3, Fig.

   7 shows a closed cascade top part for toxic reactions viewed in section on the line N -- O of Fig. 8, Fig. 8 shows a section on line R - S of Fig. 7, and Fig. 9 shows an arrangement of a plurality of reaction vessels using different components.

   Figures 1, 4 and 2, 5 respectively show the essential details of the construction of two kinds of the vessel base parts 1, 2. The base vessel part 1 having a double wall 4 is made of steel and is enamelled. The internally located bracket plates 7 serve to fix a partition wall 5 which has bottom clearance.

   A bearing block 8 serves to receive a geared motor (not shown) and to mount an agitator 9 by means of clamping bearings 10. The heating or cooling of the contents of the reaction vessel is effected through the double wall 4, an inlet connection 15 being fitted tangentially to the wall 4. Straps 11 made of steel are provided for mounting the vessel.

   For reactions without supply or dissipation of thermal energy, a vessel base part 2 is provided which is made of compounded material, for example polyvinyichloride with polyester laminate. It may alternatively be manufactured of steel or special steels without the use of special tools. The internal and external fixtures correspond to the vessel base part according to Fig. 1. In Figs. 2 and 5 the partition wall 6 is constructed as a cooling pocket. The construction to form a reaction vessel is effected with the cascade top parts or headpieces according to Figs. 3, 6, 7 and 8. The open cascade top part 3 with an outlet duct 13 of semi-cylindrical cross-section is made of special steels. The fixed joint to the base part 1 or 2 is made by means of a flanged ring 12. Sealing is effected with a PTFE-seal element. The outlet duct 13 serves for the continuous outlet of the contents into the next reaction vessel and by means of a flange 14 the headpiece 3 can be firmly connected to a closed cascade top part 21 for toxic reactions as shown in Figs. 7 and 8.

   This closed cascade top part 21 is used with the vessel base part 1 or 2 when reactions with readily boiling substances, highly exothermic reactions or reactions with cleavage of toxic gases are carried out.

   The continuous supply of the reactants is effected via the inlet connecter 17 which ter minutes below the surface of the liquid level in the reaction vessel and thus forms a gas lock. The outlet duct in the case of this top part is constructed as an outlet connecter 19.

   The gas-tight sealing lof the agitator 9 iso effected by a simmer ring in the bearing bush 18, because in this case the clamping sleeve bearing 10 is dispensed with and the mounting of the agitator is effected by a ball-bearing in the bearing bush 18. The inserted pipe connections 16 are provided for the erection of reflux coolers or for fixed connecting pipes of toxic substance destruction plant. The smaller connections 20 serve for pH measurement, temperature monitoring and for dosing reaction substances.

   All the components are made in such a way that any desired variants adapted to the par ticular production process are possible, as is shown, for example in Fig. 9.

   WHAT WE CLAIM IS:- 1. A reaction vessel for selective use as an open top or closed top vessel, comprising in combination a vessel base part and either a closed top part connectible to the base part and having at least one inlet connecter for the reactants and at least one weir outlet conneoter for the reaction products located

   below said inlet connecter, said top part in oluding measuring, gas or vapour outlet con necters, or an open top part connectible to the base part and having an outlet duct of semi cylindrical cross-section, the connection between the vessel base part and the open or dosed top part being constructed as a flange joint 2. A reaction vessel as claimed in claim 1, wherein the vessel base part is provided with a bearing block supporting an agitator.
3. 3. A reaction vessel as claimed in claim 1 or 2, wherein the vessel base part is of double wall construction.
4. 4. A reaction vessel as claimed in any of the preceding claims, having a volume of 20 to 500 litres, preferably 50 to 100 litres, and a ratio of vessel diameter overflow height of 0.8 to 1.2 : 1.
5. 5. A reaction vessel as claimed in claim 1 and substantially as herein described with reference to and as shown in the accompanying drawings.