Abstract: For use in gas phase polymerization apparatus having an agitator in a fluidized bed polymerization reactor, the present invention provides a gas distributor which has holes, and caps covering the respective holes from above and each having an opening oriented in a substantially horizontal direction at an angle of about 90 to about 135 deg with, and outwardly of, a tangent to a circle centered about the center of the reactor whereby an increase in the gas solid ratio can be prevented in the region above the distributor to ensure efficient discharge of the polymer produced, and the polymer particles can be prevented from falling into a gas room thereunder.

Abstract: The variations in the delivery rate of additive caused by fluctuations in a system for the preparation of a polyurethane reaction mixture from flowable reactants and an additive, in particular a blowing agent, are kept within negligible limits by subdividing the supply pipe (4) to the mixing head (6) into a main pipe (8) and a subpipe (9) and introducing the additive into the side stream, which is substantially smaller than the main stream.

Abstract: Apparatus and method of hydrating a particulated polymer and producing a well treatment gel includes a mixer for spraying the polymer with water at a substantially constant water velocity and at a substantially constant water spray pattern at all flow rates of the water. A centrifugal diffuser is connected to the mixer for receiving the mixture, centrifugally diffusing the motive energy of the mixture, and hydrating the mixture into a gel. A centrifugal separator and constant velocity jet pump may be connected between the mixer and the centrifugal diffuser. A dilution valve is connected to the discharge of the centrifugal diffuser for mixing water with the gel at a substantially constant mixing energy at all flow rates of the gel and producing a diluted gel. A viscometer may be connected to the discharge of the dilution valve for measuring the viscosity of the diluted gel and regulating the flow of gel from the centrifugal diffuser to the dilution valve in order to control the viscosity of the diluted gel.

Abstract: A fluidized bed-type polymerization apparatus has an upper blowing equipment installed at a definite height in the fluidized bed area. Through the equipment, a part of the circulating gas and a part, or the whole, of the fresh feed material is blown, thereby to prevent the formation of lumps of polymer in the fluidized bed portion, owing to improved intermixing at the upper portion of the fluidized bed, as well as efficient heat-removal at that portion.

Abstract: There is provided an apparatus for suspension polymerization to produce polymer particles having uniform size. The apparatus has a droplet forming device with at least one orifice and a recycle line which recycles the aqueous dispersion medium through the droplet forming device, a first reactor and a second reactor. The apparatus can produce polymer particles having uniform particle size.

Abstract: In devices for the production of a reaction mixture, which forms a foamed plastic, from at least two reaction components and a foaming agent, it is possible to determine the content of foaming agent in a reaction component mixed therewith in that an intermediate container is provided for this mixture. The intermediate container is provided with a circulating line in which are arranged a circulating pump and a temperature-compensating viscometer. Optionally, the foaming agent content can be automatically adjusted to the theoretical value via a computer and pulse lines by influencing the drive means of the dosing pumps for the respective reaction component and the foaming agent.

Abstract: A vertical reactor system having a plurality of substantially vertically aligned reaction compartments one on top of the other, the reactant materials (and catalyst and solvent, if desired), flowable from a first top compartment through intermediate compartments, if any, to a bottom compartment from which a desired product of a reaction of the reactant materials is withdrawn, the compartments having inlets for the addition of additional reactants, catalysts, or solvents and outlets for withdrawing by-products, vapors, and water from any compartment, and processes for producing products using such a system. In one embodiment the product is a liquid epoxy resin. Stirring impellers may be provided in any compartment. A liquid seal may be provided on a shaft for the impellers and, in one embodiment the seals in each compartment may be elevated above the liquid in the compartments.

Abstract: The invention is directed to a method and an arrangement for continuously producing a rubber base compound and a rubber end compound in a single stage for vehicle tires, drive belts, conveyor belts as well as for industrial rubber products. The rubber base compound and the rubber end compound are produced continuously in one and the same mixing arrangement which includes a twin-screw extruder.

Abstract: A polymerizing apparatus for polymerizing a monomer having an ethylenically unsaturated double bond which is equipped with a polymerization vessel having an agitator and a return nozzle to a gaseous phase part and with a circulating pipeline extending from said polymerization vessel and connected to said return nozzle of the polymerization vessel through a heat exchanger, in which said return nozzle is installed such that it discharges a reaction mixture in the direction which is tangential to the circumferential wall of the vessel and in which the agitator is rotated. Scale of a polymer can be prevented from depositing in the polymerization vessel and it is possible to reduce the number of fish eyes of a molded product such as a sheet into which the polymer obtained by the present polymerizing apparatus can be worked.

Abstract: An apparatus for dissolving dry polymer particles in water consisting of a bin which contains the powdered polymer, a feeding means for the delivery of the polymer to a vortex chamber, a feed line for the delivery of water into the vortex chamber, an eductor, a centrifugal pump and a tank which contains an agitator.

Abstract: In an automated solid-phase peptide synthesizing apparatus comprising at least one reaction vessel containing particulate resin as an insoluble support matrix which anchors elongating peptide chains yielded through coupling-assembly formation of peptide bonds, mixing agitation of reagents, as well as circulation agitation of washing solvents flushing the coupling-associated reaction solutions, introduced in peptide chain-assembly process steps into the reaction vessel, is effected by the bubbling of an inert gas forcibly passed through the reagents or washing solvent via a drainage port of the reaction vessel, in order to promote peptide synthesis. A removable agitation stabilizer is inserted into the reaction vessel as a barrier for inhibiting extra-vessel escape, due to action of the bubbling inert gas, of the reagents as well as the washing solvents, and of the support matrix anchoring the elongating peptide chains.

Abstract: Polymer particles having a small particle diameter and a narrow particle diameter distribution are obtained by a continuous polymerization method which does not accompany an increase of cohering products attaching to an inner face of a reaction vessel and an air-bubble invasion and, in which stirring of a material solution for polymerization is easy. An emulsion polymerization reaction or a suspension polymerization reaction is carried out by supplying a material solution for polymerization continuously to a clearance between coaxial double cylinders, which have stretched toward a direction crossing a horizontal plane, from the end side of the cylinders, by rotating at least one of the double cylinders round the axis and thereby, causing Taylor vortices. The polymer particles thus-formed are obtained by through the other end side of the double cylinders to the outside.

Abstract: An apparatus for preparing foams exhibiting a uniformly small cell size, a minimum number of ruptured cell walls and a smooth surface from foamable curable compositions comprises means to transport the ingredients of a foamable, curable composition to the input of a static mixer in which the ingredients of the composition are blended to homogeneity prior to being extruded into an exit zone and through an exit orifice. The length to diameter ratio of the mixing zone and the diameter of the exit orifice are within specified ranges.

Abstract: an automated synthesizing apparatus which comprises a raw material, reagent and solvent supply unit, a reaction unit, a purification unit provided with HPLC and CPC, and a freeze-drying unit for freeze-drying a purified product supplied from the purification unit. The raw material, reagent and solvent supply unit includes a plurality of reservoirs for containing raw material, reagents and solvents; volumetric tubes and gas-liquid boundary sensors for the quantification of the raw material, reagents and solvents from the reservoirs; flow-lines for supplying the raw material, reagent and solvent from the reservoirs towards subsequent steps; and solenoid valve assemblies disposed on the respective flow-lines for selectively closing and opening such respective flow-lines.

Abstract: An apparatus for converting synthetic resin into oil thermally decomposes the synthetic resin by heating it in a heating vessel, thereby producing oil. The apparatus includes the heating vessel and a heating furnace. The synthetic resin fed into the heating vessel is stirred. At least the lower part of the heating vessel is disposed in the heating furnace. By providing a radiating fin on the outer surface of the upper part of the heating vessel disposed outside the heating furnace or providing a heat-insulation on the outer surface of the upper part of the heating vessel disposed in the heating furnace, the temperature rise in the upper part of the heating vessel is limited.

Abstract: In order not to have to rinse, during breaks in production, oscillating mixheads such as are used for the manufacture of free-flowing, plastic-forming reaction mixtures, an exchangeable insert part held in position by means of a clip and preferably consisting of plastic material is provided in the mixhead. The insert has a mixing chamber and an outlet channel. This insert part can be disposable or reusable.

Abstract: A vertical reactor system having a plurality of substantially vertically aligned reaction compartments one on top of the other, the reactant materials (and catalyst and solvent, if desired), flowable from a first top compartment through intermediate compartments, if any, to a bottom compartment from which a desired product of a reaction of the reactant materials is withdrawn, the compartments having inlets for the addition of additional reactants, catalysts, or solvents and outlets for withdrawing by-products, vapors, and water from any compartment, and processes for producing products using such a system. In one embodiment the product is a liquid epoxy resin. Stirring impellers may be provided in any compartment. A liquid seal may be provided on a shaft for the impellers and, in one embodiment the seals in each compartment may be elevated above the liquid in the compartments.

Abstract: Apparatus and methods for accurately determining the gel time of oxygen inhibited polymerizable compositions is provided. Gel times in these compositions are related to dissolved oxygen concentration. The inventive method and apparatus use a small diameter capillary tube filled with the composition and sealed thereafter at one end to include an air space between the end of the liquid column and the sealed end of the tube. A pulsed force of air is applied to the unsealed end of the tube which causes the column of liquid and air/liquid interface to move in accordance with the amplitude of the pulsed air force. A motion detector sensor is located at the air/liquid interface. A light source is then applied to the polymerizable column within the tube causing it to gel. Recording equipment appropriately connected to the motion detector sensor visually describes the motion of the air/liquid interface which becomes zero at the gel point.

Abstract: The invention relates to a process for the production of low-gel spinning solutions-surprisingly stable in their solution viscosity-of segmented polyurethane urea elastomers in highly polar solvents, such as dimethyl formamide or dimethyl acetamide, characterized by the use of multistage jet reactor, and to a multistage jet reactor.

Abstract: A reactor for the solution polymerization of volatile monomers equipped with an agitator to cause splashing and droplet formation to reduce volatile monomer accumulation in the vapor space.

Abstract: A polymer activation apparatus for activating and diluting a liquid polymer with water includes, a vessel defining a cylindrical chamber divided into first and second processing zones, the polymer and water being supplied to the first processing zone, an impeller located in the first processing zone subjecting the polymer to a high shear rate for a short contact time to initiate dissolution and activation of the polymer, and the polymer being moved to the second processing zone under the force of the water supplied to the first processing zone, a second impeller in the second processing zone subjecting the polymer to a lower shear rate for a longer period to continue the polymer dissolution and activation process.

Abstract: Polymer activation apparatus for activating a liquid polymer emulsion in dilution water includes a first processing zone in which the polymer solution is subjected to a high mean shear rate for a predetermined period of time, and a second processing zone in which the polymer solution is subjected to a low mean shear rate for a longer period of time. The shear rates and residence times in the zones are selected to produce maximum activation in less total processing and aging time than that required in known apparatus.

Abstract: Through three separate passages opening in a common plane at right angles to one another into a mixing chamber, three components of a reactant polyurethane or polyurea elastomer composition to form in a mold cavity are introduced. One of the components is an aliphatic polyether amine having primary amino function and substantially free from free hydroxyl groups, catalysts with tertiary amino groups, carbon dioxide as a carbamate reactive with the polyether amine and optionally other inert gases and conventional polyurea additives. The second component is a polyisocyanate or prepolymer thereof and the third component C is water. The reacting mixture is formed through a throttle gap into the mold to form low-density foamed products under low fuming conditions and has no unreacted diisocyanates.

Abstract: An apparatus for the direct fluorination of solid particles of polymeric resins capable of being fluorinated in which the solid particles are in contact with the gaseous phase of fluorine/dense carrier fluid in a tubular reactor with an internal mechanical device comprising a rotatable shaft with screw flight, multiblade or wire brush that mechanically fluidizes the solid phase. The design of the internal mechanical device is a function of the diameter and length of the tubular reactor and the reaction time and other physical properties of the solid particles of polymeric resins. The internal mechanical device prevents agglomeration of the solid particles and promotes uniform contact with the gaseous phase by inducing mobility to the solid particles. The enhancement of solid surface contact with the gaseous phase assists the reaction between the solid polymeric resin and the elemental fluorine, as well as the heat dissipation into the dense carrier fluid.

Abstract: Method and apparatus for synthesizing biopolymers, such as polypeptides and polynucleotides. The apparatus includes plural reaction vessels in which subunit coupling to biopolymers in a particle suspension is carried out. The vessels are connected to common valving structure for use in mixing the suspension and removing suspension liquid. In one embodiment, a robotic arm in the apparatus is operable to transfer reaction solution to the reaction vessels, and to transfer particle suspensions from the reaction vessels to a mixing vessel and back to the reaction vessels. The method can be used to produce preferably equi-molar amounts of different-sequence biopolymers, such as polypeptides and polynucleotides.

Abstract: A continuous horizontal reactor system and process for employing such a system. In one embodiment, a reactor system having a cylindrical multi-compartment vessel, the compartments intercommunicating via a common overhead space or separated spaces from which vapor with reaction product or by-products may be removed, and from which liquid effluent with reaction products or by-products may be removed and reactants and catalyst flowable into each compartment and agitators in each compartment. Such a reactor system for producing liquid epoxy resins. Processes using such a reactor to produce reaction products, e.g. liquid epoxy resins.

Abstract: The present invention relates to a process and a device for introducing a catalytically active powder into a reactor (20) for gas phase alpha-olefin polymerization. The device comprises a storage vessel (3) containing the powder, a metering valve (4) delivering metered quantities of the powder into an intermediate chamber (5) comprising at least one obstacle (6) separating an upper part (5a) of the chamber (5) comprising an auxiliary gas inlet (2a) from a lower part (5b) terminated by an outlet orifice (5c). A connecting pipe (18) connects the outlet orifice (5c) to a mixing device (8) situated on a conveying pipework (15) communicating with the reactor (20). The powder is introduced into the reactor in a dilute suspension form and in a more uniform rate.

Abstract: An apparatus for producing a homogeneous material from a mixture of a plurality of reactive components is disclosed. Included is an injector having first and second spaced apart end portions. The injector defines a plurality of cylindrical passages each having a predetermined length and a predetermined cross sectional area. The passages have an inlet at the first end portion and an outlet at the second end portion. Each of the reactive components is delivered at a pressure within a predetermined pressure range to the injector. The reactive components are adapted to pass through the passages, exiting the injector at respective flow velocities. A mixing tube having a first end portion, a second end portions, and a middle portion of a predetermined length is also included. The middle portion is located between the first and second end portion. The second end portion of the injector is in communication with the first end portion of the mixing tube.

Abstract: A batch type process for purification of a polymer resin, in which a predetermined volume of acid is rapidly emptied and stirred into a fixed volume of polymer slurry for chemically treating impurities in the slurry, is converted to a continuous operation by supplying a substantially constant stream of polymer slurry and a controlled stream of acid to a mixing vessel. pH control of the polymer slurry required for effective purification of the polymer resin is achieved by manipulating the flow rate of the acid stream responsive to a feedforward control signal which operates in conjunction with a feedback signal. The feedforward signal is based on an upstream measurement of slurry flow rate to the mixing vessel and the feedback signal is based on a downstream pH measurement of slurry flowing from the mixing vessel.

Abstract: A reactor for highly viscous media with a horizontally oriented reactor casing having an inlet and an outlet in which a cage-like rotor is mounted in a rotary manner by means of stub shafts. To the cage-like rotor are fixed elements, e.g., rings, which are immersed in and thoroughly mix the media. A stripping rotor is provided coaxially with the cage-like rotor. Both rotors rotate within one another and mix and deliver the media and thereby form free surfaces. In addition, they also clean one another through a scraping action.

Abstract: A mixing device exhibiting a mixing chamber, feed and recirculation lines for components and for the component mixture. A control piston reciprocates inside the mixing chamber between a recirculation position where the feed and recirculation lines are in fluid communication and a mixing position where the components impinge and mix in the mixing chamber. At least one component has a straight line recirculation path from its feed to return line through a radial slot in the control piston. A bypass line branches off from at least one feed line and opens into the mixing chamber at a mixing input duct in the same radial plane as a mixing input duct for a second component.

Abstract: The invention relates to a method for maintaining a continuous mixing extending throughout the transversal section of the reactor space in a liquid containing solids and gas, and for simultaneously separating gas or gas and solids from the liquid. The invention also relates to an apparatus whereby the mixing is maintained, and simultaneously at least one phase is removed from the liquid under agitation. In a particularly advantageous fashion the method and apparatus of the present invention are suited for the stirring of bioreactors, as well as to removing gas and solids from the said reactors.

Abstract: A rotating processor is disclosed. The apparatus includes a hollow enclosed rotor, a rotor drive, internal space to hold particulate porous reaction or separations media which may be porous, lines connecting the center and periphera of the internal space with the exterior through fluid line seals, valving to control fluid flow, gradient makers, and a microprocessor to control and monitor the entire system. Optionally the rotor may be spun with the axis vertical or horizontal, and may be used as a conventional column at rest. The rotating processor permits any synthetic or separative process utilizing particulate or solid phase supports, or separations involving phases of different density to be accomplished under conditions which facilitate precise control of fluid flow and minimization of both micro- and macro-anomalous flow. A computer-controlled flat multiport valve system is also described to facilitate programmed scheduling of reagents through the rotor.

Abstract: An apparatus for producing rubber mixtures, comprising: as a master batcher, a ram kneader than operates in a batch-type process; a ram-less final mixer that is disposed below the ram kneader, also operates in a batch-type process, and has a greater volume capacity than does the ram kneader, with the final mixer having a mixing chamber that is provided with rotors; an essentially vertically disposed transfer channel for the transfer of a master batch from the ram kneader to the mixing chamber of the final mixer; and one or more withdrawal or exhaust openings disposed above the mixing chamber of the final mixer in walls of at least one of the transfer channel and the mixing chamber of the final mixer.

Abstract: The invention relates to a method for maintaining a continuous mixing in a liquid throughout the transversal reactor space, and for simultaneously separating from the liquid either another liquid, a solid material or possibly gas. The invention also relates to an apparatus whereby the mixing is maintained and simultaneously another phase is separated from the liquid under agitation.

Abstract: A plant for producing chain-type ammonium polyphosphate from ammonium orthophosphate and phosphorus pentoxide in the presence of gaseous ammonia comprises a reactor having rotatable mixing, kneading and comminuting tools in its interior and a feed pipe for the solid starting materials, an introduction pipe for ammonia, a gas discharge pipe and a discharge line for the reaction product, all of which are flow-connected to the interior of the reactor. The discharge line of the reactor is also connected for material flow to a mixing apparatus. A discharge device, which is controlled by the power consumption of the drive motor of the reactor, is arranged in the discharge line.

Abstract: High molecular weight, essentially uncrosslinked polychlorophosphazenes are prepared by bulk polycondensing a monomer of the formula P.sub.2 NXCl.sub.2, in which X is an oxygen or sulfur atom, e.g., N-dichlorophosphoryl- or N-dichlorothiophosphoryl-P-trichlorophosphazene, and wherein at least that final stage of polycondensation following cessation of evolution of PXCl.sub.3 is carried out in a stirred reaction zone, such stirred reaction zone including means to prevent the accumulation of polycondensate on the stirrer.

Abstract: In order to improve mixing efficiency of highly viscous fluid, while structural simplicity being maintained, two types of stirring impellers are employed in a single stirring apparatus. One of such stirring impellers is a large flat impeller and the other is a slanted or screw-shaped impeller to cause an up-and-down flow. This principle is further utilized in a stirring tower type polymerization reaction apparatus which has an array of mixing areas, each of which corresponds to the stirring apparatus above, and partitions between the mixing areas. The partitions are disposed so that the temperature of reaction can be controlled easily. Undesirable effects such as "dead space", space in which flow is insufficient, and the attachment of gelled material to the rotational shaft can be avoided while rather obvious, but no less important, advantages of efficient and uniform mixing, etc., are secured.

Abstract: A process for the solution polymerization of volatile monomers in a reactor equipped with an agitator to cause splashing and droplet formation to reduce volatile monomer accumulation in the vapor space.

Abstract: A method and apparatus for conducting chemical reactions in polyphase systems by using emulsifying means for the liquid components consisting of ultrasound emitters or turbines, in the absence or presence of a solid catalyst in fixed bed form with which the emulsified liquid components are brought into immediate contact by continuous circulation.

Abstract: A multi-shaft thin-layer reactor for treating fluid materials in which gaseous material is present during such treatment. The treatment involves the addition of gas to the fluid material or the removal of gas therefrom. The reactor includes a housing in which a plurality of axis-parallel conveying shafts are disposed. The housing is cylindrical and the shafts are disposed around the inner periphery thereof in such a manner that each shaft meshes with the two shafts adjacent thereto. The meshing shafts jointly define the outer periphery of a treatment chamber within the housing. At least one sun-and-planet roller extrusion assembly rotates the shafts and is adjacent at least one end of the shafts in a form-locking manner. The conveying shafts also scrape against the internal wall of the housing so that thin layers of the fluid materials fed into the reactor are formed and these thin layers become disposed on the conveyor shafts.

Abstract: A continuous stirred-tank reactor suitable for the liquid-phase oxidation of an aromatic alkyl to an aromatic carboxylic acid is provided with vertically disposed, relatively narrow baffles on the reactor wall and with oxidizing gas inlet means below the agitator in the reactor. The baffle width is about 0.02 to about 0.04 times the diameter of the reactor.

Abstract: A stirring reactor for a viscous material. The reactor comprises a stirring vessel; a revolvable shaft provided in the vessel; a surface layer stirring vane provided on the revolvable shaft in the vicinity of interface of the gas and the liquid to be stirred; a stirring vane having at least a pair of radially directed multiple portion blades which extend radially towards the inner wall, a first of which blade portions is fastened on the revolving shaft below the upper layer stirring vane and the other of which blade portions extends outwardly radially from said first portion to terminate close to the inner wall of the vessel; and baffle plates provided on the inner side wall at positions substantially parallel to the surface layer stirring vane, and at a height between the heights of any stirring vanes having multiple blades.

Abstract: A mixing head for high pressure mixing of reactive chemicals defines a mixing chamber for receiving and mixing oppositely directed impinging chemicals and having an outlet through which the chemicals are discharged after mixing. A separate tubular nozzle assembly for each chemical is replaceably mounted in the body of the mix head and has an inlet for receiving one of the chemicals and an orifice communicating with the mixing chamber. Each nozzle assembly includes a nozzle body and an annular sleeve or ring shaped orifice member of abrasion resistant material defining the orifice and a tubular support fabricated from a non-metallic material, e.g., an internally lubricated super polyamide, snugly spacing the annular orifice member from portions of the nozzle body defining the associated passage and also interfitting with the annular orifice member in supporting relation.

Abstract: A device for mixing and dispensing pasty masses comprises a container 10 ing two parallel compartments 12, 13 for accommodating two components which react with each other and an opening 14 including two concentric spaces 15, 18 each communicating with a respective one of the compartments 12, 13. A static mixer 11 is screwed onto the container opening 14 and includes a sleeve-like separator 24 at its entrance end. In the assembled state, the separator 14 is sealingly contiguous with a cylindrical partition 16 which separates the two spaces 15, 18 of the container opening 14 from each other. The location where the two components are combined is thus axially spaced from the location where the component strings are interrupted upon removal of the mixer 11, so that clogging of the container 10 caused by mutual carry-over of the components is prevented.

Abstract: In plant for the production of alkylated resins from an alcohol of boiling point greater than 100.degree. C. at atmospheric pressure, comprising an alkylation reactor, a distillation column, a condenser, and a separator, structure is provided to ensure that contact between descending alcohol-rich liquid phase and the vapor stream of alcohol and water ascending from the reactor is confined essentially to the walls of the column.

Abstract: The invention is directed to a device and a method for the application of any adhesive. The device include a hydraulically actuated mixhead which contains means to controllably deliver the components of a polyurethane based adhesive to the point of application of the adhesive and the means to separate between the components until the reaction between them is desired. Typically the components are in the form of streams and comprise an isocyanate stream and a polyol stream, the volume and flow velocity of each of which are in accordance within the invention hydraulically controlled.

Abstract: An apparatus for continuously charging a liquid reactant with a gas is provided. The gas is dispersed in the reactant through a hollow stirrer in a gassing tank. The quantity of gas introduced per unit time is kept constant.

Abstract: A polymer activation apparatus for activating and diluting a liquid polymer with water includes, a vessel defining a cylindrical chamber divided into first and second processing zones, the polymer and water being supplied to the first processing zone, an impeller located in the first processing zone subjecting the polymer to a high shear rate for a short contact time to initiate dissolution and activation of the polymer, and the polymer being moved to the second processing zone under the force of the water supplied to the first processing zone, a second impeller in the second processing zone subjecting the polymer to a lower shear rate for a longer period to continue the polymer dissolution and activation process.

Abstract: An apparatus for processing high viscosity materials consisting of a heatable, horizontal vessel with a product inlet on the one end and a product outlet on the other end and, parallel to the axis of the vessel, a heatable rotating hollow shaft, supporting a plurality of heatable stirrer elements, and between these stirrer elements, fixed to the wall of the vessel, stationary baffle and scraping elements of different configurations.Each stirrer element comprises one to four stirrer wings, each with two hollow spokes and a peripheral, hollow ring-segment connecting the spokes, and fixed to the peripheral end of these ring-segment connections trailing product dragging blades.