DE102012112162B4 - basket reactor - Google Patents

Abstract

Basket reactor, in particular for the mechanical, chemical and/or thermal treatment of products in a housing (1), in which a shaft (6) with disc elements (5) is arranged and interacts with counter-elements (27.1-27.3), the counter-elements (27.1 -27.3) are assigned to a mixing basket (7) which is arranged around the shaft (6), characterized in that the counter-elements are configured as kneading and scraping rings (27.1-27.3) rotating with the machine and are provided with projections (29.1, 29.2 or 29.3) are provided, which graze along the inner surface (24) of the disc elements (5).

Description

The present invention relates to a basket reactor according to the preamble of claim 1.

State of the art

Mixing kneaders of this type serve a wide variety of purposes. The first to be mentioned is evaporation with solvent recovery, which can be carried out batchwise or continuously and often under vacuum. In this way, for example, distillation residues and in particular toluene diisocyanates are treated, but also production residues with toxic or high-boiling solvents from chemical and pharmaceutical production, washing solutions and paint sludge, polymer solutions, elastomer solutions from solvent polymerisation, adhesives and sealants.

The apparatus is also used for continuous or batch contact drying of water and/or solvent-moist products, often also under vacuum. The application is primarily intended for pigments, dyes, fine chemicals, additives such as salts, oxides, hydroxides, antioxidants, temperature-sensitive pharmaceutical and vitamin products, active ingredients, polymers, synthetic rubbers, polymer suspensions, latex, hydrogels, waxes, pesticides and residues from the chemical or pharmaceutical production, such as salts, catalysts, slags, spent liquors. These processes are also used in food production, for example in the production and/or treatment of block milk, sugar substitutes, starch derivatives, alginates, for the treatment of industrial sludge, oil sludge, organic sludge, paper sludge, paint sludge and generally for the treatment of sticky, encrusting viscous products and waste products and cellulose derivatives.

Degassing and/or devolatilization can take place in mixing kneaders. This is applied to polymer melts, after condensation of polyester or polyamide melts, to spinning solutions for synthetic fibers and to polymer or elastomer granules or powders in the solid state.

A polycondensation reaction can take place in a mixing kneader, usually continuously and mostly in the melt, and is mainly used in the treatment of polyamides, polyesters, polyacetates, polyimides, thermoplastics, elastomers, silicones, urea resins, phenolic resins, detergents and fertilizers.

A polymerization reaction can also take place, also usually continuously. This applies to polyacrylates, hydrogels, polyols, thermoplastic polymers, elastomers, syndiotactic polystyrene and polyacrylamides.

In general, solid/liquid and multi-phase reactions can take place in the mixing kneader. This applies above all to baking reactions, in the treatment of hydrofluoric acid, stearates, cyanates, polyphosphates, cyanuric acids, cellulose derivatives, esters, ethers, polyacetal resins, sulfanilic acids, copper phthalocyanines, starch derivatives, ammonium polyphosphates, sulfonates, pesticides and fertilizers.

Furthermore, reactions can be solid/gaseous (e.g. carboxylation) or liquid/gaseous. This is used in the treatment of acetates, acids, Kolbe-Schmitt reactions, e.g. BON, Na salicylates, parahydroxybenzoates and pharmaceutical products.

Liquid/liquid reactions occur in neutralization reactions and transesterification reactions.

Dissolving and/or degassing in such mixing kneaders takes place in the case of spinning solutions for synthetic fibers, polyamides, polyesters and celluloses.

A so-called flushing takes place during the treatment or production of pigments.

A solid-state post-condensation takes place in the production or treatment of polyester and polyamides, a continuous mashing, e.g. in the treatment of fibers, e.g. cellulose fibers with solvents, crystallization from the melt or from solutions in the treatment of salts, fine chemicals, Polyols, alcoholates, compounding, mixing (continuously and/or batchwise) in the case of polymer mixtures, silicone compounds, sealants, fly ash, coagulation (in particular continuously) in the treatment of polymer suspensions.

Multifunctional processes can also be combined in a mixer-kneader, for example heating, drying, melting, crystallizing, mixing, degassing, reacting - all this continuously or in batches. Polymers, elastomers, inorganic products, residues, pharmaceutical products, food products, printing inks are manufactured or treated in this way.

Vacuum sublimation/desublimation can also take place in mixing kneaders, whereby chemical precursors, e.g. anthraquinone, metal chlorides, organometallic compounds, etc. are cleaned. Furthermore, pharmaceutical intermediates can be manufactured.

A continuous carrier gas desublimation takes place, for example, in the case of organic intermediates, such as anthraquinone and fine chemicals.

Essentially, a distinction is made between single-shaft and twin-shaft mixing kneaders. A multi-shaft mixing and kneading machine is in the CH 506 322 A described. There are radial disc elements on a shaft and axially aligned kneading bars arranged between the discs. Frame-like mixing and kneading elements from the other shaft engage between these discs. These mixing and kneading elements clean the discs and kneading bars of the first shaft. The kneading bars on both shafts in turn clean the inner wall of the housing.

These known twin-shaft mixing kneaders have the disadvantage that they have a weak point in the area where the two shaft housings are connected due to the eight-shaped housing cross section. When processing tough products and/or during processes that take place under pressure, high stresses arise in this area, which can only be controlled by complex design measures.

• - Abdichtung der Wellen gegen Druck oder extrem tiefes Vakuum,
• - Dichtungen,
• - Explosionssicherheit der Gehäuse,
• - Rundlaufgenauigkeit im Gehäuse und
• - Gehäuseabdichtung

bekanntOther disadvantages of twin-shaft machines are related to

• - Sealing of the shafts against pressure or extremely deep vacuum,
• - seals,
• - explosion-proof housings,
• - Concentricity in the housing and
• - Housing sealing

known

These known mixing kneaders are already through a basket reactor after DE 195 36 946 A1 improved, such a basket reactor being particularly suitable for processes under pressure.

Furthermore, from the DE 195 36 945 A1 a mixing kneader of the type mentioned above is known in which at least one ring is arranged between the mixing elements around the shaft and has a larger diameter than the shaft.

Task

The present invention is based on the object of further improving this basket reactor with an internal mixing basket, with particular emphasis being placed on extensive cleaning of all internal surfaces, improved mixing and kneading effects and improved transport of the product in the housing.

solution of the task

The features of the characterizing part of claim 1 lead to the solution of this problem.

On the one hand, so-called wall scrapers are provided according to the invention, with which the mixing basket can clean an inner wall of the housing. These wall scrapers have the considerable advantage that they can be kept relatively small, so that their power absorption is particularly important when removing heavy incrustations on the inner surface of the Housing is reduced. The wall scrapers can also be arranged on the surface of the mixing basket in such a way that they overlap when the mixing basket is unwound, so that any point on the inner surface of the housing can be cleaned.

In a preferred embodiment, the surface of the mixing basket is also provided with openings in the form of a grid. These openings have the advantage that the product can get from the space between the mixing basket and the inner surface of the housing into the mixing basket itself and back again. This significantly improves the mixing and shearing of the product.

For example, if the mixing basket is made of metal, the openings can be punched into the mixing basket. A small strip remains, which is then bent up so that it protrudes from the openings and thus forms a wall scraper. This simplifies the manufacture of the mixing basket.

The wall scrapers should be positioned in the direction of rotation of the mixing basket and offset at an angle to the axis of the housing. Positioning at an angle has the advantage that the wall scrapers slide under the incrustations on the inner wall of the housing and scrape them off the inner wall. The oblique positioning of the wall scrapers in turn has the advantage that a transport effect is thereby exerted on the material to be mixed, so that the product is constantly circulated in the housing.

Mixing and kneading counter-elements should also be improved and designed to be more variable in their function. For this purpose, a kneading counter-element runs obliquely to the housing axis and runs through the mixing basket, passing close to the shaft. Here, a part of the shaft is cleaned, but mainly two adjacent mixing and kneading elements are cleaned, ie two mutually facing inner surfaces of mixing and kneading elements, provided these are designed as disc elements. In the following wear these Mixing and kneading elements contribute significantly to the rigidity of the mixing basket.

Successive mixing and kneading elements should be arranged around the shaft in a mutually rotated manner. Furthermore, the cross-section of the mixing and kneading elements should be designed in such a way that the disk elements are cleaned as efficiently as possible. For this purpose, it is advisable to design the cross section of the mixing and kneading counter-elements similar to wedges or ploughshares, so that a scraping edge always runs along the inner surface of the disc elements.

The shape of the mixing and kneading elements that slide over the disc elements is very important. Depending on their design, a kneading or a stripping effect is achieved. The latter is particularly important for improving the surface renewal of the product to be treated.

The number of mixing and kneading elements that graze over the disk elements can also be compacted as required. This is an important feature of the present invention.

The wall scrapers and the other elements that contribute to cleaning the inner wall of the housing, the shaft and the disk elements can also be designed in such a way that they do not clean completely, but rather intermittently. This creates a kind of "potato furrow". The following cleaning element then shifts the "hump" into the "furrow". By angling the cleaning element, a rotating movement can be created in order to always get fresh product on the surface. In the profile, it is also better, the ratio of hill to furrow is not 1:1 but in a different ratio so that more cutting planes are generated.

This "potato ridge" also results in complete occupation of the surface, while with a simple design of the cleaning elements, the upper part of the housing or the disc elements never come into contact with the product. This allows the tolerances of the kneader to be increased.

The disc elements can also be configured differently. They can run continuously around the shaft or consist of individual disc sections with interruptions. In terms of cross-section, they can be rectangular or, for example, conical or pyramid-shaped. The latter design is particularly important in order to increase the heating surface, to stiffen the shaft and to prevent product build-up on the shaft.

Shaft and mixing basket preferably rotate around the same axis. There can be applications in which the shaft in particular does not rotate while only the mixing basket rotates around the world. This considerably simplifies the construction, in particular the sealing and storage. It is also conceivable that only the shaft rotates, but the mixing basket stands still. In this case, however, the inner wall of the housing is not cleaned. Above all, the invention also includes the fact that both components rotate in the same or different directions, optionally at the same or different speeds. There should be no limit to the inventive idea here.

The mixing basket can move ahead or behind the main shaft in a relative movement. The kneading elements ensure that the product is transported radially, alternating radially outwards and radially inwards. Mixing discs instead of mixing and kneading elements can be designed as perforated discs, slotted discs or spoked discs and thus create large product surface renewals.

character list

• 1 einen schematisch dargestellten Längsschnitt durch einen erfindungsgemässen Korbreaktor;
• 2 einen Querschnitt durch den Korbreaktor gemäss 1;
• 3 eine teilweise dargestellte Abwicklung eines Mischkorbs aus einem Korbreaktor gemäss 1;
• 4 eine Draufsicht auf eine Niveauscheibe;
• 5 einen Querschnitt durch ein weiteres Ausführungsbeispiel eines Korbreaktors;
• 6 einen Querschnitt durch einen weiteres Ausführungsbeispiel eines Korbreaktors;
• 7 einen teilweise dargestellten Längsschnitt durch ein weiteres Ausführungsbeispiel eines Korbreaktors;
• 8 einen Querschnitt durch das Ausführungsbeispiel des Korbreaktors gemäss 7;
• 9 einen teilweise dargestellten Längsschnitt durch ein weiteres Ausführungsbeispiel eines Korbreaktors;
• 10 einen Querschnitt durch das Ausführungsbeispiel des Korbreaktors gemäss 9;
• 11 einen teilweise dargestellten Längsschnitt durch ein weiteres Ausführungsbeispiel eines Korbreaktors;
• 12 einen Querschnitt durch das Ausführungsbeispiel des Korbreaktors gemäss 11;
• 13 einen teilweise dargestellten Längsschnitt durch ein weiteres Ausführungsbeispiel eines Korbreaktors;
• 14 einen Querschnitt durch das Ausführungsbeispiel des Korbreaktors gemäss 13;
• 15 einen teilweise dargestellten Längsschnitt durch ein weiteres Ausführungsbeispiel eines Korbreaktors;
• 16 einen Querschnitt durch das Ausführungsbeispiel des Korbreaktors gemäss 15;
• 17 einen teilweise dargestellten Längsschnitt durch ein weiteres Ausführungsbeispiel eines Korbreaktors;
• 18 einen Querschnitt durch das Ausführungsbeispiel des Korbreaktors gemäss 17;
• 19 einen teilweise dargestellten Längsschnitt durch ein weiteres Ausführungsbeispiel eines Korbreaktors;
• 20 einen Querschnitt durch das Ausführungsbeispiel des Korbreaktors gemäss 19;
• 21 einen teilweise dargestellten Längsschnitt durch ein weiteres Ausführungsbeispiel eines Korbreaktors;
• 22 einen Querschnitt durch das Ausführungsbeispiel des Korbreaktors gemäss 21;
• 23 einen teilweise dargestellten Längsschnitt durch ein weiteres Ausführungsbeispiel eines Korbreaktors;
• 24 einen Querschnitt durch das Ausführungsbeispiel des Korbreaktors gemäss 23.

Further advantages, features and details of the invention result from the following description of preferred exemplary embodiments and from the drawing; this shows in

• 1 a schematically illustrated longitudinal section through an inventive basket reactor;
• 2 according to a cross section through the basket reactor 1 ;
• 3 a partially illustrated development of a mixing basket from a basket reactor according to FIG 1 ;
• 4 a plan view of a level disc;
• 5 a cross section through another embodiment of a basket reactor;
• 6 a cross section through another embodiment of a basket reactor;
• 7 a partially illustrated longitudinal section through another embodiment of a basket reactor;
• 8th a cross section through the embodiment of the basket reactor according to 7 ;
• 9 a partially illustrated longitudinal section through another embodiment of a basket reactor;
• 10 a cross section through the embodiment of the basket reactor according to 9 ;
• 11 a partially illustrated longitudinal section through another embodiment of a basket reactor;
• 12 a cross section through the embodiment of the basket reactor according to 11 ;
• 13 a partially illustrated longitudinal section through another embodiment of a basket reactor;
• 14 a cross section through the embodiment of the basket reactor according to 13 ;
• 15 a partially illustrated longitudinal section through another embodiment of a basket reactor;
• 16 a cross section through the embodiment of the basket reactor according to 15 ;
• 17 a partially illustrated longitudinal section through another embodiment of a basket reactor;
• 18 a cross section through the embodiment of the basket reactor according to 17 ;
• 19 a partially illustrated longitudinal section through another embodiment of a basket reactor;
• 20 a cross section through the embodiment of the basket reactor according to 19 ;
• 21 a partially illustrated longitudinal section through another embodiment of a basket reactor;
• 22 a cross section through the embodiment of the basket reactor according to 21 ;
• 23 a partially illustrated longitudinal section through another embodiment of a basket reactor;
• 24 a cross section through the embodiment of the basket reactor according to 23 .

A basket reactor P according to the invention has according to 1 an approximately cylindrical housing 1, which serves to accommodate a mixture to be treated. This mixed material enters the housing 1 through an inlet 2 and can be removed through an outlet 3 after treatment. Any vapors or vapors that are produced can be drawn off through a vapor nozzle 4 .

Disc elements 5 are provided on a shaft 6 which is rotatably mounted in the housing 1 for treating the material to be mixed. In the present case, six disk elements 5 are indicated on the shaft, but any other kneading or stirring elements can also be provided on the shaft. The disk elements 5 are preferred only because they allow better heat transfer. For this purpose it is possible to introduce a heat transfer medium into the shaft 6 which then also flows through corresponding cavities in the disc elements 5 .

According to the invention, the shaft 6 together with its disc elements 5 is encompassed by a mixing basket 7 which rotates about an axis A concentrically with the shaft 6 . Here, the shaft 6 engages on the one hand in a plain bearing 11.1 in a pipe section 8 of the mixing basket 7 and on the other hand is supported against the housing 1 via a bearing 9 . The mixing basket 7 or the pipe section 8 is supported on the one hand by a bearing 10.1 against the housing 1 and on the other hand encloses the shaft 6 with a plain bearing 11. It goes without saying that the mixing basket and shaft are sealed against one another by additional, corresponding sealing elements or bearings can be supported. For the sake of clarity, these are neglected or not identified in more detail.

Both the shaft 6 and the mixing basket 7 are each connected via couplings 17 and 18 to a drive 19 and 20, respectively.

The mixing basket 7 forms an in 2 and 3 shown grid-like surface 21, which is provided with openings 22. Wall scrapers 23 are bent out of these openings 22 and serve to clean an inner wall 15 of the housing 1 . This is particularly important when the housing 1 is heated, with a corresponding heat transfer medium being heated through annular chambers 16, as in 1 evident, is conducted.

The wall scrapers 23 are otherwise employed in the direction of rotation. They preferably not only serve to clean the inner wall 15 of the housing 1, but also as a transport scraper. That is why they, as in 3 indicated, employed at an angle to the longitudinal axis A of the housing 1, so that they transport the product in one direction of the housing during rotation. In this way the product passes from the inlet 2 mentioned above to the outlet 3 or is moved back and forth in the housing if this is desired.

Kneading counter and scraping elements 12 extend inside the rotating mixing basket 7, one kneading counter element 12 being sufficient for a mixing space between two disk elements 5, but several kneading counter and scraping elements 12 can be provided depending on the mixing frequency and requirement. The successive in the longitudinal direction of the housing 1 mixing and kneading elements 12.3 in the successive mixing chambers can, as in the 9 and 10 implied each rotated by 120°, but any arrangement is possible here.

In 1 and 5 it can be seen that a kneading counter element 12 in each case cleans the two mutually facing inner surfaces 24 of two adjacent disc elements 5 . For this purpose, the counter kneading and scraping element 12 is set at an angle in relation to the longitudinal axis A of the housing 1 . Cross-sectionally, the kneading and scraping element 12 is preferably designed like a ploughshare, so that a scraping edge 25 points towards the inner surface 24 .

In 1 it is also shown that one or more co-rotating level discs 26 distributed along the length of the machine can be installed in such a way that a controlled flow can be guaranteed for low-viscosity products. One of these level discs 26 is in 4 shown.

According to 6 Kneading counter and scraping elements 12.1 are employed in or against the direction of rotation of the shaft 6 in such a way that they run tangentially.

According to the 7 and 8th counter kneading and scraping elements 12.2 pass through the mixing basket 7, running obliquely; first near the inner surface 24 of a disk element 5, then near the shaft 6, where they also cross the kneading space to the next disk element 5, and the rest of the way near the surface 24 of that disk element 5. Thereby the in a kneading space are between two Disc elements 5 provided kneading and scraping elements 12.2 arranged crossing each other.

Kneading counter and scraping elements 12.3 according to 9 and 10 are, as mentioned above, each arranged offset by 120° and designed in an angled manner, whereby they also traverse the kneading space between two disk elements 5 here. A knee 28 of the respective angular kneading counter and scraping element 12.3 is close to the shaft 6.

The counter kneading and scraping elements 12.4 according to 11 and 12 have a larger design than those according to 9 and 10 , where they are also designed arcuate. However, they loop around the shaft 6, with two kneading counter and scraper elements 12.4 being provided for each kneading space.

Kneading counter-elements 12.5 according to 13 and 14 together form a triangle within a kneading space between two disk elements 5, passing tangentially on the shaft 6.

The kneading and scraping elements 12.7 and 12.8 according to 15 and 16 are elliptically shaped, whereby the ellipse can be twisted so that, as in 15 recognizable, forms an eight in side view. This twisted design is missing in the kneading counter and scraping element 12.8. Here the elliptical design lies in an inclined plane.

According to the 17 and 18 perforated or slotted discs 13 are provided instead of the counter kneading and scraping elements. These can have a wide variety of passage structures. Some of these are in 18 implied.

The rotating slotted and perforated disks 13 can also be supplemented or replaced by co-rotating kneading and scraping elements 12, especially if the mixing and kneading counter-elements 12 are designed as they are in FIGS 5 and 6 are shown.

The shape of the disk elements 5 does not need to be conical, moreover, the disk elements 5.1 can, as in FIGS 19 and 20 shown, can also be designed like a disc. A perforated or slotted disk 13 is provided between two such disk elements 5.1 and is provided with corresponding openings.

In the 21 until 24 loosely rotating kneading or scraper rings 27.1, 27.2 and 27.3 can be seen, whereby these can have any configuration. They are preferably provided with projections 29.1, 29.2 or 29.3. These projections rub against the inner surface 24 of the disc elements 5 along.

Reference List

1

Housing

2

entry

3

discharge

4

exhaust vent

5

disc elements

6

Wave

7

mixing basket

8th

pipe section

9

camp

10

camp

11

bearings

12

kneading counter element

13

Perforated and slotted disc

14

15

inner wall

16

ring chamber

17

coupling

18

coupling

19

drive

20

drive

21

surface

22

breakthroughs

23

wall scraper

24

Inner surface

25

scraping edge

26

level washer

27

kneading and scraping rings

28

Knee

29

head Start

A

axis

Claims (2)

Basket reactor, in particular for the mechanical, chemical and/or thermal treatment of products in a housing (1), in which a shaft (6) with disc elements (5) is arranged and interacts with counter-elements (27.1-27.3), the counter-elements (27.1 -27.3) are assigned to a mixing basket (7) which is arranged around the shaft (6), characterized in that the counter-elements are configured as kneading and scraping rings (27.1-27.3) rotating with the machine and are provided with projections (29.1, 29.2 or 29.3) are provided, which graze along the inner surface (24) of the disc elements (5). basket reactor claim 1 , characterized in that the projections (29.1, 29.2 or 29.3) of a kneading and scraping ring (27.1-27.3) brush along the inner surfaces (24) of disc elements (5) lying opposite one another.

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