DE1619731C3 - Device for evaporating volatile components from viscous mixtures - Google Patents

Description

3 4

The mixture to be treated will be mistaken for the kneading cylinders, as well as a thrust of the

through the mixture opening out at one end of the container, which allows its rapid passage through the

Lines fed and enters the device at the other end.

axial direction through the gap that distinguishes the device according to the invention

between each cylinder and the cylinder is therefore very substantially separated from the degassing

closing container inner wall is recessed. Extrusion presses with several of the usual conveyor

The volatile constituents escape in longitudinal screws and with vacuum connections in the working direction to the end of the container, where the treated chamber, the one transverse to the feed axis of the mixture Mixture is discharged, and not in the transverse direction, are arranged and only serve some as in the known devices. One can use the io percentages or traces of those contained in the product To discharge the vacuum to the outlet line for the volatile components. The various components create in order to reduce their evaporation. Shapes of this extrusion do not lead to cheap. Formation of a single central space between

The cylinders can be smooth or threaded, the screws with sufficient volume to accommodate the

Have ribs or grooves. When smooth, 15 is added to completely evaporate the volatiles

the mixture is only moved in thin layers. components required expansion of the mixture

In the other cases, the cylinders intervene to allow.

other, whereby they are along their original Further features and advantages result from

Diameter with a certain amount of play, which corresponds to the following description of an example

The thickness of the layer of the mixture to be treated 20 has the embodiment of the device according to FIG

determined to move. You thus call an additional invention. In the drawing shows

Shear off the mixture and enlarge Fig. 1 is a cross section along the line 1-1 of the

its treatment surface without the dimen- F i g. 2 and

Solutions of the device increase. Of course, Fig. 2 is a longitudinal section along the line 2-2 of the

borrowed one must with the enlargement of the volume 25 Fig. 1.

the evaporation chamber the number of cylinders and / In the embodiment shown there is the

or increase their diameter. Device consisting of a cylindrical interior 1,

The outer shell of the device can be circulated by flanges 2 and 3 at its ends a heat-exchanging medium that is closed, which is attached to the interior 1 by bolts or brings the mixture to the working temperature and 30 other means are attached. The interior 1 and also the amount of heat generated by friction and that which forms the outlet end of the device Kneading the mixture arise, discharges, double flange 3 are enclosed by a jacket 4, the be walled. The cylinders are an advantageous circuit of a heat-exchanging medium adhesively hollow, in order to likewise enable the circulation of the heat. This is exchanged through the lines 5 and a more effective temperature 35 and discharged through the lines 6. In the interior of the mixture to be treated, space 1 is provided with four threaded cylinders. the 7 arranged, their axes to each other and to

With this device, high percentages of the space 1 axis XX can be parallel. The cylinders

of 50% and more of the volatile constituents are stored in flanges 2 and 3 and can

are separated, without that it was not a contamination \ o by any in the drawing DAR

the mixture comes. You can thereby put means outside of the flange 2 in rotation

sensitive thermoplastic polymers are also added,

not preserved discolored. The cylinders 7 are engaged with each other and

From the description below it can be seen that each cylinder is arranged with its

know that the evaporation chamber is a sufficient 45 original diameter two other cylinders

Must have volume so that it touches the area to be treated.

mixed can expand greatly. This is possible The surface lines along which this contact

with at least three cylinders, which takes place in this case, are shown in FIG. 1 through their intersections A,

but a sufficiently large diameter have B, C, D shown with the plane of this figure. The

must, so that the exhaust steam chamber is large enough 50 square ABCD with curved sides represents the

for the effective treatment of the mixture. Before cross-section of the evaporation chamber 8 of the device

preferably four cylinders or one in a transverse plane.

larger number of cylinders used, which can be seen that the chamber 8 of the cylinders 7

the same total volume the creation of an ab- is completely included. Your longitudinal walls will be

Steam chamber with a much larger usable 55 due to the part of the axis facing the XX

Enable volume. Side surface of each cylinder formed between

The diameter of the cylinder thus influences the contact surface lines. The rest

the size of the evaporation chamber. It influences each side surface of each cylinder 7 is from the

but not the treatment of the mixture because the inner wall 9 of the space 1 enclosed so that the

this device neither the task of a strand 60 chamber 8 is the only room in which a development

press still has a mixer. The cylinders have tension and evaporation of the volatiles

constant slope and constant profile so that the mixture can take place.

not a compression like in an extrusion press This mixture is introduced through the lines 10

zone and a kneading zone is present, which results from the one end in the room 1 in the

Incline or enter from the thread profile of the worm 65 transverse direction and along the surface lines

result. In the device according to the invention the points of intersection B and D open,

If the cylinders are not smooth, the mixture leaves space 1 through the open

shear of the mixture, which is not with a voltage in the flange 3 between the rotary

pin-forming part of reduced cross-section of each cylinder and the bearing of this pivot is recessed.

The volatile constituents emerge through an axial bore 11 in the flange 3 in the extension the chamber 8 is drilled and can be connected to a vacuum source. This hole 11 is surrounded by drainage openings for the mixture that has been freed from the volatile constituents.

The cylinders 7 are hollow in this example; its inner bore 12 is from a heat exchange medium flows through. This is introduced through an axial tube 13 and exits through the space, that between this tube and the inner wall of the part of the cylinder 7 of reduced cross-section which is mounted in the flange 2.

The mode of operation of the device is as follows:

The mixture to be treated, which is introduced through the lines 10 into the space 1, is of the cylinders 7 detected and along the movable walls of the cylinders regularly and in thin Layers distributed. The mixture is pushed between these cylinders and the inner wall 9 moves and constantly transferred into the central space 8, in which it expands and from its volatile constituents is freed. The mixture is then recaptured and again thinner in shape Layers distributed on the movable walls. The room 8 therefore completely fulfills its task as Evaporation chamber eliminating the risk of the mixture being deposited on the walls this chamber, which are constantly being renewed.

The volatile constituents, the release of which is largely due to the spread of the mixture in Form thin layers is facilitated, eventually emerge through the bore 11, which is preferably is under vacuum. Through the heat exchange lines 5,6 and 13 can inside the Device must be maintained at the temperature that is most favorable for evaporation, either in terms of the amount of heat used to heat the mixture, or in terms of Dissipation of the heat that occurs as the mixture spreads in thin layers. That of the volatiles freed mixture, which in the device under the simultaneous action of the continuous supply of the mixture and the thread of the cylinder 7 will eventually advance Discharged through the flange 3. It is not due to charred residue of the volatiles discolored, as is the case when using the known evaporation devices. According to the invention it is thus possible to obtain practically uncolored thermoplastic polymers, even with polymerization mixtures, which contain a high proportion of unreacted monomers.

Of course, it is also possible, above all, instead of cylinders with the same diameter to use cylinders of different diameters for smooth cylinders.

1 sheet of drawings

Claims (3)

1 2 by harmful impurities in the product in claims: the later stages of evaporation of volatile constituents are adversely affected by the 1. Apparatus used for vaporizing volatile currently known vaporizing devices. Components from viscous mixtures, in particular 5 Various attempts have already been made special polymerisation mixtures, made up of the tar-containing deposits an elongated container with an avoidance and evaporation without the risk of Evaporation chamber and at least three in the container to carry out contamination. So it was recommended ter arranged rotatable cylinders with par- the exhaust steam chamber to a temperature above allel axes aligned with the container axis, io the melting temperature of the polymer-containing gel each of which has to be heated with a mixture of working cycles in order to avoid deposits, touched, characterized in that it was also found that the discolored the cylinder (7) with its axis too- deposits to a small extent on surfaces turned side surfaces form the evaporation chamber (8) aluminum or its alloys. In order to form and the inner wall of the container (9) the remaining 15 but is not a complete solution to the problem Lent side surface of each cylinder (7) encloses. achieve because the substances to be evaporated in each 2. Device according to claim 1, characterized in the case with the fixed walls of the Abdampk that the evaporation chamber (8) come into contact through the filling chamber and because such a longitudinal bore (11) with the outside of the container probably the volatile constituents, as well as the polyin Connection is and to a vacuum source 20 merisatschichten tend to be on these walls is connectable. adhere and eventually char or tar too 3. Apparatus according to claim 2, thereby forming. They then fall back into the polymer, indicates that the longitudinal bore (11) axially contaminate them in a disruptive manner,
directed and of outlet openings for the mixture that has been freed from the volatile constituents in order to avoid these impurities. leave so that the jacket of the evaporator is then on the screws or rollers are adjacent. In this case but would be an expansion of the volatile constituents The invention relates to a device for preventing and the evaporation of volatile components from viscous 30 due to the missing expansion chamber not or pasty mixtures, for example from more under satisfactory conditions,
plastic, rubber-like or very viscous Mas- The subject of the invention is now a Vorrichsen. In particular, it relates to a device for the evaporation of volatile constituents from the evaporation of monomers, additives or viscous mixtures, in particular polymerization impurities from polymerization mixtures, with which the risk of impurities when exiting the polymerization stage. Such a movement of the mixture practically completely stripped devices is usually called evaporation, but at the same time an effective evaporation of the devices. to be separated components are guaranteed The currently known evaporation devices can be used. This device consists of a long standing from a heated container in which 4 ° elongated container with an evaporation chamber and one or more screws or rollers rotate. at least three rotatable cylinders arranged in the container are connected to an expansion chamber with cylinders aligned parallel to the container axis, which have a vacuum connection through the axes, from each of which the volatile constituents can escape with ardene. Example game touches and is characterized by these devices are effective, but have 45 that the cylinder with their axis of the container also considerable disadvantages. The more cursed side surfaces of the vapor chamber form components that condense and surrounds the remaining side wall of the expansion chamber on the surface of each cylinder on the inner wall of the container,
collect, become overheated and form tar or this way the mixture will char at its. The resulting tar or carbonaceous deposits in the device that enter the device contaminate the polymers in the course of and in thin layers along the moving part of the treatment and discolor them throughout the walls. It then becomes that under vacuum in an undesirable manner. set central space, its volume This contamination is all the more unpleasant the dimensioned so that the mixture can expand well higher the percentage of the polymers 55 and the volatile constituents due to the bursting is to be separated components. She is particularly good at releasing layers of the mixture. The annoying the new polymerisation or copolymers are then recirculated, this being the case merization process in which the conversion is again applied as thin layers on the movable The degree of efficiency is deliberately distributed over between 40 and 80% of the walls and again in the central ones limited values. Here the amount of 60 space is transferred. volatile constituents are naturally very high and · can be in the device according to the invention more than half of the polymerization obtained - all walls of the evaporation chamber movable and mixed amount. These procedures are extremely new during the rotation of the cylinders interesting both in terms of yield and constant. All the layers that come with the moving technical structure as well as with regard to the qua- 65 walls will be instantly quality of the products obtained, which are very dense again with the mixture to be treated. Composition and molecular weight distributed and can therefore neither form nor tar have lung. But the technical interest can burn out.