DE102007041796A1 - Processes and apparatus for preparing pre-condensed resin solutions - Google Patents

Abstract

The invention relates to a process for preparing precondensed resin solutions, wherein a) the starting materials of the resin solution are at least one aminoplast generator and at least one carbonyl compound, b) the starting materials are subjected to direct heating in at least one heating stage (C1). Furthermore, the invention relates to a device which is particularly suitable for carrying out the method.

Description

The The present invention relates to a method according to claim 1 and An apparatus according to claim 90, in particular for the production can be used by pre-condensed resin solutions. In this case, a fast heating rate can be achieved by means of direct heating and products with a narrow distribution of the degree of polymerization getting produced.

precondensed Resin solutions find versatile use, especially in the woodworking industry, z. B. in the production of Laminates or chipboard. In their preparation, the polymerization reaction stopped so early that the resin is still soluble is and thus processed in dissolved form can. During further processing, the resin then becomes condensed completely, so the polymerization completed. The resin gets thereby its duroplastic properties.

There Polymerization reactions in the form of a stepwise condensation reaction The stopping of this reaction before its completion inevitably leads to expiration to a mixture of substances of different degrees of polymerization in the resin solution. So there is a spectrum of low condensed substances (eg educts and monomers) and stronger condensed polymers. For many applications is however, it is desirable to narrow the width of this spectrum as possible.

It is known, pre-condensed resin solutions in large, heatable stirred tanks batchwise (ie in batch process) to produce.

To the starting materials (for example, aminoplast, carbonyl and if necessary, catalyst) normally introduced cold into the vessel, then heated to reaction temperature and after completion the reaction time cooled again. The heat input takes place by means of heat transfer of heated Surfaces (eg the boiler wall) on the fluid. The im technical scale representable conditions of heat exchange surface and reactor volume limit the rate at which the reaction solution is heated can be. Should the heating-up times be as economical as possible? Measure are shortened, this leads to an inhomogeneous temperature distribution in the reactor. Consequently become products with a broad distribution of the degree of polymerization generated.

Lie one or more reactants at the beginning of the reaction not in solution, but as suspended solids before, this disadvantage is still reinforced: By the slow heating goes first only a part of the solid in solution over and stands thus already available for the reaction while the other part of the solid redissolved later will and can react. As a result, the spectrum of the Degree of polymerization in the resulting resin solution. Another disadvantage of the low heating rate of conventional methods lies in the fact that the time required for the heating up reducing the space-time yield and thus the production output corresponding assets.

These Disadvantages can be partially due to a continuous operation be caught: The in the heating stage of such a reaction system Heated surface is continuous throughout and thus used more effectively for heating. Therefore, you can favorable conditions of surface to volume and an increase in the heating rate within certain limits be achieved.

In continuous process can even be a very rapid temperature increase can be achieved: passes the cold or preheated educts continuously in a fully mixed and at reaction temperature located stirred tank, so finds a nearly jump-like temperature increase instead of. The larger this temperature jump is, the more longer, however, the mean residence time in this fully mixed Be a zone. The consequent widening of the residence time distribution in the reaction system, however, results in a broad distribution prevailing degrees of polymerization in the resulting resin solution.

Of the with the heat input through heated surfaces associated disadvantage of an inhomogeneous temperature distribution in the Heating stage of the system can be in previous methods even by continuous operation can not be avoided.

Continuous methods are for. B. in the patent DE-1595035 and layout DE-1720306 described.

It is Z. B. from the US patents US 4413113 . US 2927097 or the patent DE-2161052 known to perform condensation reactions in tubular reactors.

The object of the present invention is to provide processes and devices for the production of precondensed resin solutions with as narrow a distribution of the degree of polymerization as possible. This implies, on the one hand, compliance with the lowest possible hydraulic residence time distribution and, on the other hand, the drastic minimization of spatial temperature gradients in the reaction mixture. For this purpose, it is also necessary to bring the reactants as soon as possible after their mixture to reaction temperature in order to process such material systems, in which a or several reactants are only available to some extent at low temperatures for the reaction (eg, by insufficient solubility at low temperature). In addition, this measure improves the space-time yield of the process.

It has surprisingly been shown that for this Task required, high heat input rates below Minimization of spatial temperature gradients and with only slight broadening of the hydraulic residence time distribution are possible if the heat input is not like in the hitherto known methods of heated surfaces, but via direct heating of the reaction mixture takes place.

To become the educts of the resin solution, namely at least an aminoplast generator and at least one carbonyl compound in subjected to at least one heating step of a direct heating. A Stage can have one or more apparatuses, with each one one or more (sub) areas of different process conditions. The areas can also be in the same apparatus in a spatial and / or chronological order.

Advantageous becomes a liquid in the reaction mixture Component (in particular a solvent) the possibly preheated other components in superheated state, preferably in vapor form, admixed. However, other methods of direct heating may be used be used or combined, for example: irradiation the reaction mixture (microwaves, infrared, gamma or particle radiation etc.), inductive heating (possibly with the addition of an electrically conductive, particulate phase, which separated later if necessary ), adding a chemically inert, overheated phase, which if necessary later separated etc.

The The object is also achieved by a device according to claim 89 solved. The device has at least one fumigant for the introduction of a gas or a steam for direct heating at least one liquid and / or suspension on and a stirrer, with the stirrer through essentially radially arranged blades or flow channels with regard to the at least one liquid and / or suspension.

Further advantageous embodiments are objects the dependent claims.

The Invention will be described below with reference to the figures of Drawings closer to several embodiments explained. Show it:

1A Embodiment of an arrangement with a continuous and spatially sequentially arranged sequence of process steps;

1B Embodiment of an arrangement with a discontinuous sequence of process stages arranged chronologically one after another;

2 schematic representation of a first embodiment of a continuous method and an embodiment of a continuous apparatus with a tubular reactor;

3 schematic sectional view through an embodiment of a continuous device;

4 schematic sectional view through an embodiment of a discontinuous device;

5 Embodiment of a continuous process with static mixer and calorimetric measuring section;

6 Exemplary embodiment of residence time and cooling stage in the continuous process.

7 Especially for an F: M ratio of 1.3 possible operating parameters for an embodiment of the continuous process.

Relating to 1A . 1B Embodiments of the method according to the invention are shown in the form of block diagrams. 1A describes a continuous process.

It will be in 1A the reactants of a resin solution, for. Example, an aminoplast, phenol or a phenol derivative and a carbonyl compound and a catalyst at least one heating stage 1 fed. As will be described later, a direct heating takes place in the at least one heating stage.

After heating, the product becomes the heating stage 1 at least one residence time stage 2 fed. After the substances have a predeterminable time in the at least one residence time stage 2 have spent the substances of at least one cooling stage 3 fed.

In 1A the process steps are continuously formed and spatially arranged so that they are passed through successively.

In 1B an alternative flow diagram is shown with a discontinuous procedure, in which the process step of filling 5 of the at least one heating stage 1 is performed with the starting materials. The educts may be those of in 1A represented example correspond.

At least one heating stage 1 here means that in a container several heaters with direct heating are feasible.

Subsequently, the residence in the same container or in the same containers, ie the at least one residence time 2 , Here, too, can be spent in one step or in several staggered stages.

Finally, at least one cooling step takes place 3 with a subsequent emptying and a subsequent filling.

From the 1A and 1B It is clear that the term "stage" in the context of a continuous procedure ( 1A ) may mean a spatial arrangement of apparatuses for the realization of stages. In the discontinuous case ( 1B ) stage means the temporal succession of certain operating conditions.

Relating to 2 a continuous plant is shown as an embodiment for the production of pre-condensed resin solution.

When An example is the preparation of a formaldehyde-melamine resin described, whereby also other resins, in an analog plant and can be produced with an analogous method.

When Starting materials for the resins serve Aminoplastbildner, such as. B. Urea, at least one urea derivative, at least one dicyandiamide, at least one guanamine, melamine and / or at least one melamine derivative. In principle, it is also possible that phenol or phenol derivatives can be used as starting materials. In the following, however, aminoplastics are considered.

When Reaction partner for the Aminoplastbildner serves at least a carbonyl compound, such as. As an aldehyde, especially formaldehyde is. The formaldehyde z. B. wholly or partially as a formalin solution and / or be used as paraformaldehyde.

The process is carried out in a plant which consists of several, substantially serially connected stages, which are flowed through by the reaction mixture continuously. In this respect, this embodiment is an embodiment of the principle in 1A illustrated method.

In alternative embodiments, it is also possible to switch individual stages or partial areas of the stages in parallel.

When an educt here becomes particulate melamine the metering device H1 fed to a first container M1. The melamine serves as Aminoplastbildner in the following processing.

When further starting material and as carbonyl compound here is formaldehyde (and lye) fed into the first container M1.

In a first step is a premix of the reaction components with reduced water content compared to the required Reaction mixture prepared (stirred tank M1). It can over the heating jacket of the stirred tank M1 a pre-tempering the premix are made.

about a pump P1, which is preferably designed as an eccentric screw pump is, the premix is in the heating stage C1, which is here as continuous Stirred reactor is formed, promoted. The heating stage C1 is here under an operating pressure of 6 bar.

Of the Contents of the heating stage C1 is by means of direct heating on a Temperature of about 137 ° C brought. The direct heating takes place here by introducing steam over a Control valve V2 in the heat-up stage C1.

To a temperature controller TC1 leads via the valve V2 so much steam that a corresponding discharge temperature is reached becomes. This steam condenses in the heating stage C1 to liquid Water and heated the mixture by the resulting heat of condensation on.

Around to adjust the required water content of the reaction mixture, Add more water in liquid form Control valve V1 added. This amount is via a ratio controller FV3 controlled so that the effluent from the heating stage C1 Mass flow in the correct ratio to the incoming premix stands.

The Premix is characterized in the appropriate ratio with Diluted in water, so that in the produced resin solution a solids content of about 57% sets. The described control circuits are parameterized in such a way that they are largely stationary during operation Equilibrium state.

In a specific embodiment of the described control, the control valve V1 can be controlled via a flow regulator, which in turn sets a desired value for the flow of the valve V1 from the ratio controller FV3 receives. Similarly, the flow measurement FI1 can be removed to the controller, which receives a setpoint for the flow in the pump P1 from the ratio controller FV3 and controls them accordingly.

In a further embodiment of the method (cf. 5 ), the discharge temperature of the heating stage C1 is controlled by the amount of water added via V1 by the temperature controller TC1. As much steam is added via the valve V2 that results in a suitable running mass flow from the heating stage C1 in relation to the incoming premix. This ratio is controlled by the ratio regulator FV3, which controls valve V2.

alternative To the shown here conventional control strategies can also a model-based control algorithm can be used to dilute and to control the temperature in C1.

The average hydraulic residence time of the reaction mixture in the heating stage C1 is at 45 s. This is fed into suspension Melamine in whole or in part in solution.

In other embodiments (as, for example, also in connection with the 3 and 4 can be represented), the hydraulic residence time in the heating stage may also be shorter or longer. It is advantageous if the mean hydraulic residence time in the at least one heating stage is less than 60 minutes, preferably less than 20 minutes, more preferably less than 5 minutes, most preferably less than 1 minute.

As soon as the reaction mixture is tempered so far that the reaction in should be used to a significant extent, should be advantageous the residence time over all volume elements of the reaction mixture as possible be distributed uniformly until the reaction by a sufficient Cooling is virtually stopped again.

considered one the stages or partial areas, which a corresponding temperature should, as a flow system, whose residence time distribution therefore be as close as possible.

Advantageous Thus, if the hydraulic residence time distribution of this Flow system and / or over all heating and residence time levels a standard deviation less than 60%, in particular less than 40%, in particular less than 25%, particularly preferred less than 15% and most preferably less than 9% of the corresponding Has spacetime.

For the determination of the hydraulic residence time distribution and their Standard deviation should be the following: Is the distribution at discrete points (eg by measurements in a tracer test) determined, there are sufficient (at least 100) investigation points to choose at equidistant intervals. The residence time distribution is at least up to 4.5 times the Determine spacetime and the standard deviation over the To determine the interval from 0 to 4.5 times the spacetime. Of the Centroid of the determined residence time distribution must match more than +/- 2% with the corresponding space-time. The hydraulic parameters in the determination of the residence time distribution must match the actual operating conditions.

Under Space-time is the quotient of liquid volume and flow understood.

It is advantageous if the heating rate of the inlet temperature on the starting temperature, especially in the last sub-areas the heating stage and / or in the entire heating step larger than 1 ° C per minute, especially larger than 30 ° C per minute, especially larger as 150 ° C per minute, more preferably greater than 380 ° C per minute.

The Temperature at the output of the heating is advantageously at least 90%, in particular at least 95%, especially at least 97% of the average reaction temperature in Celsius.

Also It is advantageous, depending on the educts used, that the temperature at the output of the heating stage between 60 and 230 ° C, in particular between 70 and 200 ° C, more preferably between 80 and 180 ° C and most preferably between 110 and 150 ° C.

In a particular embodiment of the process, for example, MF resins having an F / M ratio of 1.3 to 2.4, temperatures of 120 to 140 ° C are particularly advantageous. Especially for the in 7 Resin type shown as an embodiment, a temperature between 135 and 140 ° C is particularly preferred in this embodiment.

Under MF resin in this case is a resin with melamine as Aminoplastbildner and formaldehyde understood as a carbonyl compound. The F / M ratio denotes the mass ratio of the reactants formaldehyde to melamine.

The reaction mixture leaving the heating stage C1 is then passed into the residence time stage C2 designed as a tubular reactor. Under a residence time C2, a device is generally used herein understood, in which the materials are held for a predetermined time, so that a reaction can take place. It is possible, but not mandatory, that a temperature control and / or temperature maintenance is provided.

It is advantageous if the mean hydraulic residence time in the at least one residence time C2 less than 10 hours, preferably less than 2 hours, more preferably less than 45 minutes, most preferably less than 15 minutes.

In a particular embodiment of the process, for example, for MF resins having an F / M ratio of from 1.3 to 2.4, residence times of from 6 to 12 minutes are particularly advantageous. Especially for the in 7 Resin type shown as an embodiment, a residence time between 6 and 9 minutes is particularly preferred in this embodiment.

The individual pipe sections which make up this residence time stage are accommodated in a steam-heated jacket in the manner of a shell-and-tube heat exchanger, but these pipe sections are essentially connected in series. Through the tube surface, the reaction mixture is heated so that the heat of reaction and the energy required for a possible redissolution of melamine still in suspension are compensated and the temperature of the reaction mixture z. B. for in 7 as an embodiment illustrated resin type remains at about 137 ° C. The tube diameter of the residence time C2 is selected so that Reynolds numbers greater than 2300 and thus present turbulent flow conditions. The volume of the residence time C2 is chosen so that the reaction mixture flows through this zone with a mean residence time of about 7 minutes and thereby converted to a resin solution having the desired degree of polymerization.

When Criterion for the ongoing control of the degree of polymerization is the water compatibility of the produced resin solution manually determined by titration at certain intervals or continuously via an online measuring device certainly. Also, the online measurement of the following material properties of produced resin solution can be used as a criterion for the Control of the degree of polymerization are used: density, Viscosity, conductivity, refractive index, dielectric constant and / or light scattering and diffraction.

In a further embodiment of the method, the heat of reaction can also be evaluated calorimetrically as a measure of the progress of the reaction. For this purpose, at least one adiabatic measuring section A1 is placed within or after the residence time step with a measuring point for its inlet temperature (TI2) and outlet temperature (TI3) (cf. 5 ). The temperature difference can be determined very accurately and is a measure of the evolution of heat of the reaction in the measuring section.

Based such measurement results in the operation, if necessary, a Fine tuning of the degree of polymerization made manually or via a model-based control algorithm. A such voting is within certain limits over the variation possible from reaction temperature and throughput.

On the one hand however, the throughput should always remain high enough to be critical Reynolds number in the tubular reactor is not undershot. On the other hand can to achieve certain resin qualities compliance a limit temperature is required, which does not exceed during operation should be.

are to change the degree of polymerization coarser changes desired, as can in the tube bundle heat exchanger executed residence time C2 bridged individual pipe sections or cancel such a bridging, so as to change the reaction volume.

The from the residence time C2 expiring resin solution passed into the radiator W1, similar to the Dwell time C2 as tube bundle heat exchanger is constructed. The radiator W1 is thus a cooling stage W1 for the reaction mixture.

Of the Pipe diameter is chosen so that the hot Resin solution under turbulent flow conditions very fast to a temperature level below the reaction temperature is cooled. In the course of the pipe diameter is preferably chosen larger, so that with decreasing Temperature rising viscosity does not cause excessive Pressure loss leads.

The running out of the cooling stage W1, finished resin solution is passed through a valve V3, which as a pressure holding valve (see FIG. 5 ), in particular can be designed as a pinch valve. The pressure loss at this valve is adjusted so that the boiling pressure of the reaction mixture at any point of the system is exceeded with sufficient certainty. For example, for the in 7 As an embodiment illustrated resin type in the heating C1 an operating pressure of 6 bar are set. Particularly preferred is the execution of the valve V3 as a control valve (see FIG. 2 ), in particular as a pinch valve and control of this valve by a pressure regulator PIC1. The pressure regulator is designed such that it exceeds a boiling point at one or more measuring points which have a high temperature level and / or a high vapor pressure of the reaction mixture ensures pressure. This makes it possible, in a particularly economical manner, to keep the operating pressure of the plant as low as possible and to make use of the relaxation of the reaction mixture to some extent in order to overcome the pressure loss of the cooling stage (s).

At the valve V3 can be further cooling stages connect.

The direct heating is carried out in the heating step C1 of the continuous process. Due to the achievable high rates of heat input, this stage can be kept comparatively small, so that reactor containers with high backmixing (eg stirred tank) can also be used for this purpose, without an excessive broadening of the hydraulic residence time distribution in the overall system. Furthermore, for the heating step C1 and static mixers, as in the embodiment of 5 shown, or jet pumps or jet mixer 84 as in the embodiment of 6 shown, can be used.

As related to 1A executed, the heating stage C1, the residence time C2 and / or the cooling stage W1 can also be designed differently apparatus, as in 2 shown. In particular, the stages can each be distributed over more than one apparatus and can also be connected in series and / or in parallel.

In the heating step C1 become the educts of the polymerization at storage temperature or initiated in preheated condition. For the production of condensation resins are preferably urea, melamine or their derivatives used. The combination of several Aminoplastbildner can be used. Also, phenol or phenol derivatives can be used as starting materials.

When reactive component becomes a carbonyl compound, preferably one Aldehyde, in particular formaldehyde used. Other reactive components, as modifiers in the network of the resulting condensation resin can be installed, can also be added (eg, in particular, a monohydric alcohol, a polyhydric alcohol, a caprolactam, a polyol, in trimethylopropane, a sorbitol, glucose, Sulfite, toluenesulfonic acid amide, a carbamate, a salt of Maleic or fumaric acid monoamide and / or an aminoalcohol).

Also the addition of conventional additives, such as dyes can already take place in this production step.

It It is also possible to add a solvent. For most types of resin is also the addition of one or several catalysts are required, which usually consists of one Acid or a base. A variant of the method according to the invention sees the addition of the catalyst only in a downstream Level before, so that the heating stage in this case substantially not for reaction, but for heating and possibly for Mixture of the reaction components is operated.

Subsequently passes the reaction mixture brought to the reaction temperature in one or more residence time stages.

The Residence time stages are preferably flowed through as turbulent Tubular reactors formed. By the use of internals (z. B. perforated plates), which the flow velocity over the Tube cross-section even or in the edge areas but can also enlarge tube reactors be used under non-turbulent operating conditions.

The residence time stages are essentially connected in series. However, individual stages of this series can also have parallel sections 81 include, as in 6 shown

In addition, a cooling stage 80 one or more areas 82 contained, which can be bridged by a bypass, so that a volume adjustment of the residence time can be made.

If one or more of the reactants are present as suspended solids in the reaction mixture at the beginning of the reaction, their dissolution process need not be completed within the heating stage. Rather, the dissolution process may also come to an end at the beginning of the residence time stages and optionally be limited by the solubility product of the substance in the solvent, so that redissolving of the substance is only possible in the further course of the reaction. Preferably, in such a case as in 6 represented, the first area 83 the first residence time stage 80 designed so that any not yet dissolved residues are operationally controllable by deposits of undissolved residues is prevented by means of vertical flow control or increased flow rate or such in their consequences by a particularly easy accessibility for cleaning or replacement measures are made manageable.

One However, the aim of the method according to the invention is a dissolution of such substances as soon as possible and in particular not by slow heating to hinder.

The in the residence time levels transferred amounts of heat are usually comparatively small and serve only the Temperature maintenance or the tracking of the temperature in Frame of a variable in the course of the reaction temperature profile. Therefore can in these residence time a heat transfer by appropriate heat exchange surfaces (preferably through the pipe wall) without damaging it Temperature gradient comes. Are part of a for the Reaction required temperature profile or by their heat of reaction larger amounts of heat in one of the following To exchange residence time levels, this can be done via a intermediate further stage for direct heating or a Evaporators are made so that the temperature gradients in the reaction medium can be kept low.

The The reaction system formed from the stages described is in its Volume so measured that after expiration of the reaction required average residence time, the reaction solution exits from the last residence time stage. From there she will be in passed a cooling step to stop the reaction. Is a further processing of the resin solution on elevated Temperature level required (eg spray drying), so the cooling can be completely or partially omitted when further processing is sufficiently rapid or immediate Following the reaction takes place and the residence time in the reaction system if necessary shortened accordingly, so that an excessively advanced polymerization of the product is avoided.

The cooling stage has, as in 6 Preferably, a plurality of subregions are formed, designed to initially cool rapidly with the most turbulent flow conditions in correspondingly closely dimensioned tube cross sections (US Pat. 85 ) and also to minimize the spatial temperature gradients here.

Advantageously, for the first region of the cooling stage, an evaporator (preferably a flash evaporator) can be used. In the embodiment of 6 The flash evaporation is via a relief valve 89 and a separator 87 realized, which is preferably designed as a cyclone. The resulting steam gets into the condenser 88 passed and condensed there. The resulting in the separator resin solution is the next area 85 the cooling stage fed, which has a narrower dimensioned pipe cross-section.

The further the resin solution has already cooled below its reaction temperature, the slower or the greater the spatial temperature gradient, the further cooling can take place without the spectrum of the degrees of polymerization contained in the product appreciably increasing in width. Preferably, the last area (s) are 86 Therefore, the cooling stage dimensioned so that there is a lower flow rate, which may no longer allow turbulence, but limits the construction of undesirable pressure losses. In order to improve the heat exchange, in particular under non-turbulent flow conditions, corresponding static mixing elements can be arranged in the cooling stage.

A sees another embodiment of the cooling stage the addition of a cold medium (preferably that in the reaction used solvent) in the first region of the cooling stage, or immediately after the evaporator. The used for cooling Medium can also be added particulate in solid state so that it melts in the resin solution and you removes heat in this way.

To Leaving the cooling step, the resin solution further processed or stored or bottled. It should be noted that most resin types in solution are stable on storage only for a limited period of time and correspondingly early on further processing (eg to solid resin or laminates) must be supplied.

object The invention further provides a device with which in the heating stage of the continuous process described above Direct heating can be performed. in principle This device according to the invention is also for other reaction systems usable.

The Device allowed in the manner of a continuously operated gassing stirrer the merging and intensive mixing of the incoming liquid medium with a vaporous medium, which thereby condenses, so that heating of the liquid Medium by the resulting condensation heat the episode is. For this purpose, the contents of the stirred tank under maintained at a pressure above the boiling pressure at operating temperature lies. In the agitator according to the invention In addition to pure liquids, they can also be liquid Media in the broader sense, in particular also treated suspensions become.

One Gassing stirrer is just one example of one Fumigation apparatus, the z. B. also has a special Nozzle system can be equipped with which the reaction mixture is mixable.

The agitator and the essential flow processes occurring therein are in 3 shown. This embodiment may, for. B. as heating C1 in the embodiment according to 2 be used.

Preferably, the stirred tank 30 arched floors and is cylindrical. Within the inlet nozzle 32 for the premix, a hollow shaft rotates 34 facing the inlet nozzle with the sealing system 35 is sealed. This is preferably designed as a double-acting mechanical seal (details not shown in the drawing). The inlet nozzle 32 is preferably mounted axially below the mixing vessel.

On the hollow shaft 34 located and driven by this, an effective as a gassing agitator stirrer is mounted, which consists of several elements:
The stirring element has a horizontal, circular disk in the manner of a paddle or disk stirrer 40 on, the top and bottom with essentially radially extending blades 36 is equipped. On the upper blades is preferably a cover plate 37 attached, which has an inlet opening in its center. Alternatively, the blades can 36 be arranged only on one side of the disc.

The disc contains on its top and bottom discharge openings 38 through which steam is introduced for heating in the funded by the agitator reaction medium fine bubbles. This steam gets over the hollow shaft 34 fed into the disk. Within the disc is a preferably adjustable distribution system, which accomplishes the distribution of the steam outlet between the top and bottom or on the individual outlet opening. In the illustrated embodiment, the distribution system via a hollow screw ( 41 ) realized with lateral holes. The vertical positioning of these holes acting as an outlet opening, the distribution between the top and bottom exiting steam amount can be varied.

At the level of the stirring element is optionally located on the inside of the container wall, an annular guide plate 30 , This baffle 30 deflects the fluid conveyed on the underside of the stirring element in such a way that it largely remains below the stirring element and is sucked back into the stirring element from there. The conveyed on the top of the stirrer fluid is deflected so that it remains largely above the agitator and an optional guide tube 39 is sucked in again by the stirring element. By this type of flow guidance, two well-mixed areas within the stirred tank form, between which a reduced exchange of fluid exists. The inlet-side region preferably has a smaller volume than the outlet-side. As a result, rapid heating of the inflowing premix is achieved in the inflow-side region, while the second region effects reheating and further mixing between the fluid elements. This ensures intensive heating, mixing and compensation of temperature and / or concentration fluctuations in a small space. In this case, the residence time distribution of the overall system can be kept relatively narrow because the fully mixed zones of the heating stage are small in relation to the residence time and divided into two areas.

In the advantageous, upflowed through the agitator, which in 3 is shown, is the inlet nozzle 32 for the inflowing premix, preferably through the lower bottom and brought to close to the stirring element. As a result, the incoming premix can flow directly against the underside of the stirring element, so that no gas cushion can form there. As a result, the conveying efficiency of the stirring member is maintained.

In a simplified, not shown here embodiment the agitator according to the invention can the supply of steam and premix also over corresponding inlet pipes take place outside the agitator axis bring to the bottom of the stirring body.

Furthermore the agitator can optionally with baffles or baffles that are excessive Prevent rotary flow of the contents of the container. Furthermore, the agitator can also with several, in particular be equipped similar stirring bodies, the either on a common wave or on multiple waves are arranged.

The heated and mixed with the condensed vapor reaction medium leaves the stirred reactor via the outlet pipe 33 ,

object The invention is also a batch process and a corresponding device, the z. B. for those described here Preparation of resin solution can be used. in principle But this device according to the invention also usable for other reaction systems.

in the The following is the discontinuous preparation of the precondensed Resin solution using direct heating described. The reactor is designed so that it can be pressed above the boiling pressure of the reaction mixture at the reaction temperature can be operated.

At the beginning of the process cycle, the reactants of the polymerization at storage temperature or in the preheated state are introduced into the reactor. For the production of condensation resins it is preferred to use urea, melamine or their derivatives as the aminoplast former. Also, at least one urea derivative, at least one dicyandiamide or at least one guanamine, melamine can be used.

Also The combination of several Aminoplastbildner can be used. As the reactive component, a carbonyl compound, preferably a Aldehyde, in particular formaldehyde used. Other reactive components, as modifiers in the network of the resulting condensation resin can be installed, can also be added (eg alcohols). The addition of conventional additives, For example, dyes can already be used in this production step respectively. As a rule, the addition of a solvent also takes place. For most types of resin is also the addition of one or several catalysts are required, which usually consists of one Acid or a base. A variant of the invention Process sees the addition of the catalyst in whole or in part only at a later stage of the process cycle.

After completion of filling, the heating stage of the process cycle begins (cf. 1B ). In this case, the direct heating is carried out within the reaction system. Due to the achievable high rates of heat input, this stage can be kept relatively short, so that advantageously results in an increased space-time yield of the process and reactants, which are present as a solid as quickly as possible or as far as possible and made available for the reaction.

The Reaction usually sets already during the heat-up stage one, but predominantly following within one or more Residence time steps instead. A certain reaction progress is in the Usually, however, during the subsequent Cooling down.

In the residence time stage is either heat exchange only for temperature maintenance or to compensate for heat losses or to set a temperature profile in the course of the reaction progress required.

is the heat exchange during the residence time step low, it can by means of heat exchange surfaces be performed, the heated or cooled accordingly become. Preferably, a necessary heat input takes place however, with the already described means of direct heating and a dissipation of heat by evaporation. This is special then advantageous if the heat of reaction in the Synthesis of the desired type of resin is significant.

To Completion of the residence time (s) is a rapid cooling preferably by evaporation. This allows a quick Termination of the reaction. Finally, the emptying, in which the product is discharged from the reactor. The product is fed, for example, to a cooled tank, by being stored until further processing. Subsequently the process cycle starts again.

At the Cooling or during the reaction take place described evaporation steps for heat dissipation by Lowering the operating pressure in the reactor, allowing the reaction mixture begins to boil. Preferably, a solvent with chosen high vapor pressure, so here largely pure solvent evaporating. The vapors are discharged from the reactor and condensed in a condenser. Is the steam out only slightly contaminated water, so this can also directly be delivered to the atmosphere.

Around the high volumes of steam required for rapid cooling to separate out of the reaction mixture and an effective phase separation To facilitate a stirrer can be used, the just below the self-adjusting fluid level the reaction mixture is rotated. As a stirring member is preferably used a bottom-sucking paddle stirrer. to Improving the mixing of the reactor can be the agitator be equipped with a guide tube.

Furthermore the agitator can optionally with baffles or baffles that are excessive Prevent rotary flow of the contents of the container. Furthermore, the agitator with several, in particular be equipped similar stirring bodies, the either on a common wave or on multiple waves are arranged.

This procedure is related to 3 explained with reference to a further embodiment.

In the filling stage of the production cycle, the stirred reactor 51 over the inlet nozzle 60 filled with preheated formalin solution, KOH and melamine. These starting materials can be introduced individually or as premix.

The external preheating has the advantage that the time required for the temperature does not need to be taken into account in the cycle time of the actual reactor. Thus, the preheating can be slower and using waste heat, which z. B. from the product cooler or condenser, take place. A preheating can be done below the boiling point or below the temperature at which already a reaction in it considerable extent. In practice, for example, for MF resins having an F / M ratio between 1.3 and 2.4, an advantageous temperature within the range of 40 to 90 ° C results.

The Further heating of the reaction mixture is advantageously carried out fast, so that with the onset of the reaction as the aminoplast used melamine dissolved as quickly as possible. This is in the heating stage of the production cycle over a gassing stirrer water vapor into the reaction mixture registered, which, for example, 137 ° C and the desired solids content is brought.

An optimally arranged for the heating described stirring body 55 is to be placed in the lower part of the stirred reactor, it is driven by a hollow shaft and supplied with steam, which flows through appropriate outlet holes fine bubbles in the reaction mixture. An arranged above the agitator guide tube 54 ensures during the heating step that the circulation by the stirring body 55 extends to the entire liquid reactor contents.

In the residence time stage, which adjoins and which lasts for instance about 9 minutes, temperature losses can occur via an optional heating jacket 61 be compensated.

Once the desired degree of polymerization has been achieved, it is advantageous to slow down the reaction as quickly as possible by pre-cooling. This is done in the illustrated agitator by pressure reduction by means of discharge of gas through the outlet nozzle 58 with simultaneous startup of the degassing stirrer. Its stirring body 52 is located just below the surface of adjusting itself in his operation Trombe. About the guide tube 54 he sucks liquid from below, so that even during the cooling phase, the entire contents of the container is intensively circulated. The lowest pressure within the system occurs in this process on the blades of the degassing stirrer, where therefore the evaporation of the liquid preferably starts, so that the resulting vapor can escape relatively easily to the liquid surface. In the Trombe itself also takes place due to the centrifugal forces an enrichment of gas bubbles in the direction of agitator axis. These processes allow a high evaporation rate in the described agitator.

When the contents of the agitator are relieved to atmospheric pressure, the described cooling process comes to a halt at temperatures around 100 °. This is sufficient to slow down the reaction considerably. After the subsequent emptying stage, which lasts about 5 minutes, however, a further cooling of the resin produced must take place, if this can not be further processed directly. For this purpose, the finished resin solution on the outlet pipe 62 led into a cooling container by preferably pre-cooled resin solution is already produced, so that when mixing the fresh, hot resin solution results in a further rapid cooling of the same. The cooling tank is equipped with appropriate heat exchange surfaces (eg pipe coils) in order to dissipate the accumulating heat. The cooled resin solution is removed at temperatures between 30 and 80 ° C from the cooling tank for further processing or storage.

A simplified version of the in 4 The agitator shown can dispense either on the degassing and the possibility of precooling or give up the particularly favorable arranged below positioning of the gasification stirrer. In the latter case, the above-arranged stirrer under respective respective pressure conditions for both degassing and for gassing is effective when the drive shaft is designed as a hollow shaft with steam supply and corresponding outlet openings for the steam are preferably provided in the outer Rührkörperbereich. Particularly advantageous in this case is the design of the stirring body with alternately upward and downward flow channels and attachment of the steam outlet openings in the region of the downwardly directed flow channels.

Will the agitator, as in 4 shown, operated with two stirring bodies, it should be noted that in each case only one of the stirring elements is put into operation. The suction process via the guide tube 54 can then be done via the respective stationary stirrer.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 1595035 [0010]
• - DE 1720306 [0010]
• US 4413113 [0011]
• US 2927097 [0011]
• - DE 2161052 [0011]

Claims (116)

A process for the preparation of precondensed resin solutions, wherein a) the starting materials of the resin solution are at least one aminoplast generator and / or at least phenol and / or a phenol derivative and at least one carbonyl compound, b) the starting materials having at least one heating stage ( 1 , C1) are subjected to direct heating. Process according to claim 1, characterized in that the product of the heating stage ( 1 , C1) at least one residence time stage ( 2 , C2) is supplied. A method according to claim 1 or 2, characterized in that the product of the heating stage ( 1 , C1) and / or the residence time stage ( 2 , C2) at least one cooling stage ( 3 , W1) is supplied. Method according to at least one of the preceding claims, characterized in that the mean hydraulic residence time in the at least one heating stage ( 1 , C1) is less than 60 minutes, preferably less than 20 minutes, more preferably less than 5 minutes, most preferably less than 1 minute. Method according to at least one of the preceding claims, characterized in that the mean hydraulic residence time in the at least one residence time stage ( 2 , C2) is less than 10 hours, preferably less than 2 hours, more preferably less than 45 minutes, even more preferably less than 15 minutes, and most preferably less than 8 minutes. Method according to at least one of the preceding claims, characterized in that the flow system, which by the existing heating stages ( 1 , C1) and residence time steps ( 2 , C2), overall has a hydraulic residence time distribution which determines under hydrodynamic operating conditions and over 4.5 times the space-time, a standard deviation of less than 60%, in particular less than 40%, very particularly less than 25%, particularly preferably less than 15% and most preferably less than 9% of the space-time has. Method according to at least one of the preceding claims, characterized in that the heating rate in the heating stage ( 1 , C1) from the inlet temperature to the outlet temperature is greater than 1 ° C per minute, in particular greater than 30 ° C per minute, very particularly greater than 150 ° C per minute, particularly preferably greater than 380 ° C per minute. Method according to at least one of the preceding claims, characterized in that the temperature at the outlet of the heating stage ( 1 , C1) is at least 90%, in particular at least 95%, very particularly at least 97% of the average reaction temperature in Celsius. Method according to at least one of the preceding claims, characterized in that the temperature at the outlet of the heating stage ( 1 , C1) between 60 and 230 ° C, in particular between 70 and 200 ° C, preferably between 80 and 180 ° C, more preferably between 110 and 150 ° C, most preferably between 135 and 140 ° C. Method according to at least one of the preceding claims, characterized in that the cooling rate in the cooling stage ( 3 , W1) from the inlet temperature to the outlet temperature is greater than 1 ° C per minute, in particular greater than 10 ° C per minute, very particularly greater than 100 ° C per minute. Method according to at least one of the preceding claims, characterized in that the at least one heating stage ( 1 , C1), residence time stage ( 2 , C2) and / or the cooling stage ( 3 , W1) is connected in series and / or in parallel with at least one further stage. Method according to at least one of the preceding Claims, characterized in that the reaction medium after reaching the reaction temperature for a preselected Time is performed on a predetermined temperature profile, in particular is kept at a predetermined temperature. Method according to at least one of the preceding Claims, characterized in that as Aminoplastbildner at least urea, at least one urea derivative, at least a dicyandiamide, at least one guanamine, melamine and / or at least a melamine derivative is used. Method according to at least one of the preceding Claims, characterized in that the carbonyl compound an aldehyde, especially formaldehyde, acetaldehyde, isobutyraldehyde, acetone, Methyl ethyl ketone and / or diethyl ketone. Method according to claim 14, characterized in that that the formaldehyde in whole or in part as a formalin solution and / or is used as paraformaldehyde. Method according to at least one of the preceding claims, characterized that at least one catalyst or the catalysts are added wholly or partly only in one of the direct heating downstream stage to the rest of the reaction mixture. Method according to at least one of the preceding Claims, characterized in that as further components at least one acidic or basic catalyst is used. Method according to at least one of the preceding Claims, characterized in that as further components at least one modifier, in particular a monohydric alcohol, a polyhydric alcohol, a caprolactam, a polyol, a trimethylopropane, a sorbitol, glucose, sulfite, toluenesulfonic acid amide Carbamate, a salt of the maleic or fumaric acid monoamide and / or an aminoalcohol is used. Method according to at least one of the preceding Claims, characterized in that as further components at least one additive, in particular a postforming additive for Life extension is used. Method according to at least one of the preceding Claims, characterized in that as a further component at least one solvent, in particular water or a Alcohol, is used. Method according to at least one of the preceding Claims, characterized in that the direct heating at least partially by a substance, in whole or in part in gaseous or vaporous state in the rest Reaction medium is mixed. Method according to claim 21, characterized that the wholly or partially added as a vapor component Solvent is. A method according to claim 21 or 22, characterized in that the at least one heating stage ( 1 , C1) in which the admixing of the vaporous component for direct heating takes place, is subdivided into a plurality of sequential regions, so that in the first region a preheating or main heating takes place and in downstream regions a subsequent heating by addition of further gas or vapor. Method according to at least one of claims 21 to 23, characterized in that the supplied amount of gas or vapor is controlled by a ratio control, which keeps the ratio of incoming premix and running reaction mixture constant, while the temperature control in the at least one residence time ( 2 , C2) by adding a liquid component diluting the resin solution, the variable portion of which does not substantially adversely affect the properties of the resin solution. Method according to at least one claims 21 to 24, characterized in that a liquid, the resin solution diluting component and the for the direct heating supplied vapor Component material are largely identical. Method according to at least one of claims 21 to 25, characterized in that a regulation of the discharge temperature of the at least one heating stage ( 1 , C1) via the added amount of gas or steam. Method according to at least one of the claims 21 to 26, characterized in that the variability the added amount of gas or amount of steam caused variability in the solid content of the produced resin solution by a Adjustment of the feed temperature of the premix is controlled, so that after adjustment the variability of the added Steam quantity is significantly limited. Method according to at least one of the claims 21 to 27, characterized in that the variability the added amount of steam caused variability in the solid content of the produced resin solution by means of a ratio control is compensated, which the ratio from incoming premix and running reaction mixture through Addition of a premix diluting, liquid Component keeps constant. Method according to at least one of the claims 21 to 28, characterized in that for the direct heating used vapor component and the premix diluting liquid component from the same Fabric exist. Method according to at least one of claims 21 to 29, characterized in that the amounts of gaseous or vaporous and non-gaseous or vapor-fed components are controlled by a model-based control algorithm, which determines the solids content of the produced resin solution and the discharge temperature of the at least one heating stage ( 1 , C1) regulates. Method according to one of the preceding claims, characterized in that the viscosity of the reaction mixture, their density, their heat of reaction, their conductivity, their refractive index, their dielectric constant, their light scattering and diffraction are detected and evaluated as a measure of the reaction progress and in particular for correction used by operating temperature and / or system throughput. Method according to at least one of the aforementioned Claims, characterized in that the direct heating at least partly by irradiation, in particular with microwaves, Infrared radiation, X-ray radiation of the reaction mixture and / or radioactive radiation takes place. Method according to one of the preceding claims, characterized in that the direct heating at least partially by inductive heating of the reaction mixture. Method according to claim 33, characterized that the inductive heating by adding a conductive Medium is supported. A method according to claim 34, characterized that added to support inductive heating conductive medium is separated later again. Process according to claims 33 to 35, characterized characterized in that in support of the inductive Heating added conductive medium a solid, particulate Phase, in particular a metallic material. Method according to at least one of the preceding Claims, characterized in that the direct heating the reaction mixture at least partially by addition of a chemically inert, overheated Component takes place. Method according to claim 37, characterized in that that the chemically inert, overheated component in one particulate phase, in particular in the form of a metallic Solid is present. Method according to claims 37 to 38, characterized that the chemically inert component later separated again becomes. Method according to at least one of the claims 37 to 39, characterized in that the separated, chemically inert Component again to one over the reaction temperature Higher temperature overheats and again for direct heating in the at least one heating stage (C1) is used. Method according to at least one of the preceding Claims, characterized in that the direct heating with indirect heating by heated equipment surfaces in the at least one heating stage (C1) is combined. Method according to one of the preceding claims, characterized in that a premix of the educts in already preheated state, but still well below the Reaction temperature in the at least one heating stage (C1) occurs where the further heating takes place by means of direct heating. Method according to one of the preceding claims, characterized in that the at least one heating stage (C1) at least one agitator and / or at least one static Mixer and / or at least one jet mixer and / or at least having a jet pump. Method according to claim 43, characterized in that that the agitator filled so far with the reaction mixture is that above the reaction mixture no significant Gas space is more and no liquid level formed. Method according to claims 43 to 44, characterized in that that at least one stirring element as a gassing stirrer is trained. Method according to at least one of the preceding Claims, characterized in that the volume of at least one heating stage (C1) is dimensioned so that at Use of solid starting materials in suspension in the premix, these educts when leaving the at least one heating stage (C1) have largely gone into solution. Method according to at least one of the preceding Claims, characterized in that the reaction mixture further processed after passing through the heating stage in a first region of the residence time becomes, in which when using in suspension, solid Educts may not yet dissolved residues operational are controllable by means of vertical flow or increased flow rate deposits is prevented by unresolved remains or those in their Follow through a particularly easy accessibility for Cleaning or replacement measures made manageable become. Method according to at least one of the preceding claims, characterized by at least one residence time stage ( 2 , C2), which is connected downstream of the at least one heating stage (C1), wherein the at least one further stage comprises a heat exchanger, so that over the surface, a temperature control or temperature maintenance of the reaction mixture is achieved. Method according to at least one of the preceding claims, characterized in that at least one stage, in particular those, which downstream of the at least one heating stage (C1) is, is designed as a tubular reactor. Method according to claim 49, characterized that bridges individual sections of the tubular reactor can be used to reduce the reaction volume. Method according to claim 49 or 50, characterized that the tubular reactor in the manner of a Rohrbündelwärmeübertragers is constructed, but the individual pipe sections essentially have a serial connection. Method according to at least one of the claims 49 to 51, characterized in that a partial flow between at least two areas of the tubular reactor through a bypass and / or pipe sections is guided parallel to the residence time distribution to influence the reaction mixture targeted. Method according to at least one of the preceding Claims, characterized in that at least one Partial flow between two stages and / or subregions of stages is recirculated to specifically influence the residence time distribution. Method according to at least one of the preceding Claims, characterized in that a fully mixed Zone targeted to other areas in the steps is increased to the residence time distribution to influence specifically. Method according to at least one of the preceding Claims, characterized in that the flow is selected in at least one stage so that the present Reynolds number is above the critical Reynolds number and a turbulent flow prevails. Method according to at least one of the preceding Claims, characterized in that the viscosity curve the reaction solution in the reaction progress under company-like Conditions in advance in a reaction viscometer or in a model experiment measured or calculated from known material data and the sizing of Pipe sections with supercritical Reynolds number at optimized Pressure losses is achieved by putting in areas where lower Viscosities occur, larger pipe diameter be chosen and vice versa. Method according to at least one of the preceding Claims, characterized in that at least one Stage, in particular a tubular reactor, has internals, which slow down the flow rate in the center of the pipe and increase in the edge area. Method according to claim 57, characterized that the internals mounted perpendicular to the flow direction Have perforated plates, which reduced in the interior by a Density and / or size of holes applied slow down the flow and which outside a relatively higher permeability for having the fluid. Method according to claim 57 or 58, characterized that the number of fixtures is selected and the fixtures so over the run length of the stage, in particular be distributed to the tubular reactor, that the hydraulic residence time distribution the residence time distribution approximates a plug flow. Method according to at least one of the aforementioned Claims, characterized in that in a first Area of the cooling stage, an evaporation takes place, in which under pressure reduction from the resin solution a substance or a mixture of substances evaporates and as a result of the evaporation enthalpy consumed The resin solution heat is removed. Method according to claim 60, characterized that the vaporizing substance mainly from the solvent used consists. Method according to at least one of the preceding Claims, characterized in that after at least a range of at least one cooling stage at least a pressure holding valve or pressure regulator are arranged, which the Operating pressure of the respective upstream areas and stages above the boiling pressure of the reaction mixture or the resin solution hold. Method according to at least one of the preceding Claims, characterized in that behind the at least a residence time at least one pressure holding valve or pressure regulator are arranged, which the operating pressure of each upstream Areas and levels above the boiling pressure of the reaction mixture holds. Method according to claims 62 to 63, characterized that the control or pressure holding valve dead space, in particular is designed as a pinch valve. Method according to at least one of the preceding Claims, characterized in that at least one Cooling step substantially tubular is. A method according to claim 65, characterized in that the tube cross-section of the at least one tubular cooling stage with decrease the temperature and increasing viscosity of the resin solution increases, so that an excessive pressure loss is avoided. Method according to claims 65 to 66, characterized that the tube cross section in the first region of the tubular Cooling stage is chosen relatively narrow, so initially under turbulent flow conditions allows a particularly intense heat exchange becomes. Process according to claim 67, characterized in that that in the first tubular cooling stage turbulent Flow conditions by dimensioning the pipe diameter be ensured with supercritical Reynolds number, which to a previously determined viscosity curve of the Resin solution during the cooling process supports. Method according to at least one of the preceding Claims, characterized in that the at least a cooling stage comprises static mixing elements. Method according to at least one of the preceding Claims, characterized in that at least one Cooling stage and / or more of its tubular formed areas in the manner of a double tube heat exchanger and / or in the manner of a tube bundle heat exchanger are formed. Method according to any preceding claim, characterized characterized in that all conveying elements in the flow direction seen before the at least one heating stage (C1) are arranged. Method according to any preceding claim, characterized characterized in that when starting the cold plant, this up to reach a certain starting temperature in whole or in part a solvent is operated. Method according to claim 72, characterized in that that the solvent used for starting a polyvalent Alcohol, especially polyethylene glycol is. Method according to at least one of the preceding Claims, characterized in that when starting the cold plant first in at least one stage a starting temperature which is below the reaction temperature for the production of the product lies. A method according to claim 74, characterized that said starting temperature is selected so that a special quality of the resin is stable or in the first reaction zone can be generated, which in the for starting used solvent has a particularly high solubility. Method according to claim 75, characterized that the production of the resin of particularly soluble quality during the startup process in the heating stage temporarily discontinuous operation occurs while starting up the remaining stages by operation with the solvent he follows. Method according to at least one of the preceding Claims, characterized in that before or during of the starting process Resin of particularly soluble quality is added to one or more areas of the system. Method according to at least one of the preceding Claims, characterized in that the production a precondensed resin solution at least partially in a batch reactor as at least one reaction zone, wherein the reactor undergoes individual process stages in a cycle and is filled with educts in a filling stage, then next to other possible levels one Heating stage, in particular with a direct heating, a residence time and goes through an emptying stage. Method according to claim 78, characterized in that that the reaction above the boiling pressure of the reaction mixture is carried out. A method according to claim 78 or 79, characterized that the educts fed in the filling stage completely or partially as a premix, in particular as already preheated Premix present. Method according to at least one of the claims 78 to 80, characterized in that for the compensation of heat losses or to set a temperature profile over a heat exchange Heat exchange surfaces takes place. Method according to at least one of the claims 78 to 81, characterized in that between the residence time and the discharge stage is a process stage in which the reaction medium is cooled. Method according to at least one of the claims 78 to 82, characterized in that it is at the cooling only a pre-cooling of the resin solution, which after their emptying from the reactor, a further cooling in a subsequent container learns. A method according to claim 83, characterized in that the pre-cooling wholly or teilwei se is effected by a flash evaporation, which is brought about by lowering the operating pressure in the reactor. Method according to at least one of the claims 78 to 84, characterized in that the method with a operated suitable solvent, which is sufficient has high vapor pressure, so that in the flash evaporation evaporates largely pure solvent. A method according to claim 85, characterized that the solvent is water, and an emerging, u. U. low contaminated vapor to the atmosphere can be delivered. A method according to claim 84 or 85, characterized that discharged during the flash evaporation Steam is treated in a condenser. Method according to at least one of the claims 84 to 87, characterized in that during the Flash evaporation steam removed by blowing in a template with already pre-cooled liquid is treated where it condenses. Method according to at least one of the claims 84 to 88, characterized in that the evaporated from the reactor Amount of liquid due to supply of liquid is replaced, so that the level in the reactor during the precooling remains largely constant. Device, which as at least one heating stage to carry out a process after at least one of claims 1 to 89, characterized by at least a fumigant for the introduction of a gas or a vapor for direct heating of at least one liquid and / or a suspension and a stirrer with at least one Stirring body, wherein the at least one stirring body by substantially radially arranged blades or flow channels with regard to the at least one liquid and / or suspension. Device according to claim 90, characterized in that that the agitator has at least one guide tube, which the place where the from the at least one stirring body aspirated promoted liquid and / or suspension is shifted so far away from the stirring body, that an intensive circulation of the stirring body subsidized suspension and / or liquid the entire contents of the stirred container can be generated is. Device according to claim 90 or 91, characterized that the fumigation of the liquid and / or suspension fine bubbles with a vapor, which under pressure in the Liquid and / or suspension flows in, there condenses and over the thereby released evaporation enthalpy the liquid is heated. Device according to at least one of the claims 90 to 92, characterized in that the supply of liquid or suspension is done from below in style and the underside the impeller flows, so that there no gas cushion can train. Device according to at least one of the claims 90 to 93, characterized in that the gas or the steam the Stirring element fed via a hollow shaft becomes. Device according to at least one of the claims 90 to 94, characterized in that the steam over separate supply lines to the at least one stirring body is led, which are in the middle just above or just below the agitator surface end up. Device according to at least one of the claims 90 to 95, characterized in that the steam over separate supply lines to the at least one stirring body is guided, which laterally on the circumference of the stirring body just next to the stirring surface end up. Device according to at least one of the claims 94 to 96, characterized in that the ends of the leads for the supply of steam as a nozzle system are formed. Device according to at least one of the claims 94 to 97, characterized in that gas or the vapor over corresponding outlet holes emerges from the at least one stirring body. Device according to claim 98, characterized that outlet holes at the bottom, top and / or arranged on the circumference of the at least one stirring body are. Device according to at least one of the claims 94 to 99, characterized in that the quantity ratio at the top, bottom and / or on the perimeter outflowing steam controllable via an adjustable distribution system is. Device according to at least one of claims 94 to 100, characterized in that outlet bores at the backward in the direction of rotation gene side of the promotional blades are attached. Device according to at least one of the claims 90 to 101, characterized in that the expansion of the stirred tank in the axial direction is sufficiently small, so that an intensive circulation funded by at least one stirring body Suspension or liquid in the entire volume of the stirred tank results without the need for a guide tube. Device according to at least one of the claims 90 to 102, characterized in that the stirring member leaving flow is guided so that in the stirred tank give two zones between which there is a relatively low convective mass transfer. Device according to claim 103, characterized that the formation of the zones by installing an annular Guide on the inside of the stirred tank supported at the level of the stirring element. Device according to claim 104, characterized that the guide from the brims of two dished ends exists, which are placed on their smaller diameter each other and welded. Device according to at least one of the claims 94 to 105, characterized in that the stirring member in the manner of a paddle or disc stirrer from a horizontally mounted, rotating disc is made, in the Essentially radially extending delivery-effective blades are attached. Device according to claim 106, characterized that the blades on the bottom of the disc and / or on the Top of the disc are arranged. Apparatus according to claim 106 or 107, characterized characterized in that the blades on the top with a round Cover plate are completed, in the middle of an inlet opening having. Device according to at least one of the claims 90 to 108, characterized in that the agitator as Batch reactor is formed. Device according to at least one of the claims 90 to 109, characterized in that the agitator over has at least one stirring body, at which a degassing process takes place at pressure reduction, for quick cooling of the agitator contents is usable. Device according to at least one of the claims 90 to 110, characterized in that the at least one stirring body, where the degassing process takes place, just below the surface the appropriate in his operation Trombe is appropriate. Device according to at least one of the claims 90 to 111, characterized in that at least one stirring body of the gassing stirrer is identical to at least one effective at appropriate pressure reduction for the degassing Agitator. Device according to at least one of the claims 90 to 112, characterized in that at least one stirring body of the gassing stirrer in the lower part of the agitator is arranged. Device according to at least one of the claims 90 to 113, characterized in that the agitator a heatable or coolable jacket and / or a heated one or coolable coil over which its content is temperature controlled. Device according to at least one of the claims 90 to 114, characterized in that the agitator its lid has a dome over the emerging Steam can be largely removed free of liquid can. Device according to at least one of the claims 90 to 114, characterized in that the agitator baffle having.