DE19607664C2 - mixer - Google Patents

Description

Screw machine for mixing, coloring and homogenizing viscous masses with an outer and an inner housing, which are arranged coaxially to one another, with a plurality of Conveyor mixer shafts, the axes of which are parallel to the longitudinal axis of the Housing evenly distributed around the circumference of a circle, most rigid arranged between the outer and inner housings are, between the outer housing and the conveyor mix waves an outer mixing room and the inner housing and the Conveyor mixing shafts an inner mixing space is formed, which in the same direction of rotation, of which adjacent funding mixing waves mesh and each other and they Scrape off the surrounding housing with a first material feed through at least one hole in the region of one end of the outer casing in the outer mixing room and with a mate rial outlet for the mixture in the area of the other ends of the Casing.

Mixing machines, regardless of which construction principle they work, have the common disadvantage that they are only suitable for batch operation and the size of the batch Mixing machine determined in volume because of the supply container forms a unit with the mixing tool, such Batch mixer for continuous operation is therefore unsuitable are suitable because the mixing process does not occur simultaneously necessarily defined mass transport process is superimposed.  

In addition, such mixers are specially designed for viscous masses are to be cleaned with very time-consuming man hours, especially then when several different colors of the same fabric come from should be asked.

In US-PS 1 356 296 and in DE-PS 8 41 058 Screw machines shown, with an outer and a inner housing, being between the conveyor mixing shafts and the Housing an outer or an inner mixing space formed and a material inlet in the outer housing only the outer Mixing room supplied with work items, so that therefore an intimate Mixing the processed material from the inside with that of the external mixing room is not possible.

The present invention has for its object one To create mixers in which the inner ring of the worm shafts is also supplied with processed goods, so that at a forced change in a multi-flight screw profile bar longitudinal mixing effect between the outer and the inner Mixing room sets, which was not previously in worm machines is possible to quickly, intimately mix the metered masses already in the entrance area of the mixer digits.

To solve this problem is the mixer mentioned at the beginning characterized in that a second material feed through at least one hole in the area of one end of the inner Housing is provided in the inner mixing room and that the Holes are in the same area of the outer or inner Housing.

Such a mixer - for example with 8 mixer shafts - works in such a way that first the mass transfer process in Mixer is forced because the mixer shafts are provided with a sealing profile which works together with the outside and tightly enveloping along its entire length Inner housing for forced transportation to the mix well wetted surfaces of the mixer.  

This sealing profile can be used with one, two or more threads Incline without the Verar processing goods in the mixer is impaired. That just one two-course sealing profile is preferably used explained below in the description of the mixing process.

The number of mixer shafts is also determined by the process ren determined because the formation of the inner housing depends on whether the mixer can be tempered should be and must therefore have at least 8 waves, although the mixer with 6 conveyor mixing shafts in terms of mixing technology has better properties in every relationship.

Tests have shown that the outer ring of shafts with 8th Mixer shafts and one turn of the ring, i.e. 1.66 turns the mixer shafts, axial 6 gears and the inner shaft rim only conveys 2 gears in one revolution, which means that the multi-shaft screw in addition to the advantageous mixing of the two material rings rotating against each other in radial Direction, also characterized in that the two materi alkränze superimposed, axially mixed intimately be, so that volume concentrations of individual components be balanced in the processed material and complete color equality is achieved in the mix.

The type of loading of the outer and inner crane according to the invention The screw shaft is only available with multi-flight screw filen a longitudinal mixing effect, as in the same direction rotating snails could not be observed because not possible there, nevertheless their housing the snails all surrounded and thus forced transport is achieved.

There were rotating twin screws with different directions the number of flights of the screw profiles with the same screws as multi-shaft screws with different numbers of shafts formed and compared.  

The different axial paths of the two shaft rings have that Longitudinal mixing effect cited above between the outer and the inner mixing room resulting from the choice of gear and Effectiveness can be influenced by the wavenumber number; so is the lingering time behavior of this type of machine can be changed.

The material is fed into the fixed inner housing such that, advantageously, the material leakage does not, such as common with worm machines at the non-driven end,  is arranged in the center of the axis, but according to the invention the axial Material outlet channel of each worm shaft in an annular towards the melt channel, whose cross-section differs from the snail enlarged to worm, so that at the largest cross section radially offset to the center axis, the material outlet is longitudinal or takes place radially outwards, so that it is inventively by the novel material leakage is possible - because inside sufficient space was created half of the ring-shaped melt channel could be opened in this free space to arrange the fixed inner housing.

The type of training of the mixer according to the invention at the point the material discharge from the mixer enables only that defined material supply to the inner ring of the mixer shafts and is therefore a prerequisite for the exact allocation of the partial flows to the mixer shafts and the inevitable longitudinal mixing of the Components into the mix.

The mixer is therefore preferred with a two-start seal profile equipped, because with a catchy sealing profile the axial overlap completely missing; on the other hand, with a three-course sealing profile still 2.2 times the wreath coverage, however the mixer would then have to be longer because of the shorter dwell time be built, which is uneconomical.

With the mixer according to the invention completely new and thus more economical processes in material handling perform because of the extremely good and fast radial mixing, overlaid by an adjustable longitudinal mixture with forced operation in the mixing phase, which was the case with the previous batch necessary and time-consuming cleaning hours ver avoids and the entire mixing, dosing and cleaning process can be done programmatically.

The mixer is also particularly characterized in that when adding solvent or cleaning liquid instead of processed goods, self-employed within a short time  dig cleans and requires no personnel, so that derar term cleaning processes are fully automated, d. H. of the Mixer is remotely controllable and therefore programmable.

Pistons are used as metering devices for low viscosities dosing pumps in question, but preferred for higher viscosities as gear pumps, so that each shaft ring has its own dose tion is assigned.

The gear pump can advantageously also be designed that two gear pairs are driven by common shafts, whose tooth widths are like the required ratio of the individual NEN subsets of the wreaths behaves, so that the two with pumps coupled to one another only by an intermediate one The housing wall are separated and a common inlet opening have, however, for each shaft rim to be loaded one outlet each. This has the advantage that the ratio of the Material quantities are always correctly adjusted to each other, especially this ratio for a mixer with a fixed gear and Wavenumber does not change.

To avoid that the mixer by means of the overpressure metering can be overfeed and thus overloaded, is on Outer housing opposite the inlet bore an overflow bore provided. If material should leak there, is reduce the dosage accordingly.

The device according to the invention is illustrated by drawings provides and is explained in more detail below; show it:

Fig. 1 shows a longitudinal section through the process section of the mixer,

Fig. 2 shows the cross section through the mixer along the line II of Fig. 1 on the same scale.

In Fig. 1 the shortened process part of the mixer is shown in longitudinal section, with 1 denotes the outer, 2 the inner housing and 3 the mixer shafts. The mixing space, which is formed by the outer and inner shaft ring 4 , 5 , is closed at the top with the end plate 6 penetrated by the shaft and fixed or screwed with the dowel pins 7 and the screws 8 relative to the outer housing, the inner one Housing is connected via an involute toothing 2 a torsion-proof and position-centered to the upper end plate and thus also to the outer housing.

The screw-side shaft ends 3 a are radially supported by the needle bearings 6 a relative to the upper end plate and protected with Laby ring rings 6 b against the process part. After the roller bodies of the needle bearings have to run on the surface of the shaft ends because of the small center distance of the bearings from one another, it has proven to be very advantageous to coat these raceways with chromium oxide.

Non-contact and therefore maintenance-free labyrinth rings on this Site are therefore particularly suitable, especially since they are of low construction need space and secure against the ingress of foreign substances kicking fat are effective, especially if they are in a circulate thin layer of fat.  

At the upper shaft ends Evolven ten toothing 3 b are provided, on which the couplings 3 c are pushed and the procedural ends are also equipped with labyrinth rings 3 d. The assembly of the couplings is explained below.

The lower ends of the preferably solid Mischerwel len are designed as screw tips 3 e and lie in corresponding recesses of the lower end plate 9 , in which in the mixer shaft axes the same size exit bore 9 a are seen, which open into a melt channel 9 b, the cross cut from wave to wave expanded. At the point of the largest cross-section, the melt channel is continued axially and deflected radially outward in the holding plate 10 . The Mischerwel len can, however, for certain applications also consist of Evolven tenwellen with pushed screw bushes or processing elements, as shown in Fig. 2 each in half.

From Fig. 2, the inlet bores 1 a and the Überlaufboh tion 1 b for the outer shaft ring, and the inner inlet hole 2 c for the inner shaft ring can be seen, which are arranged at the same height to the upper end plate with about 3 gears spacing. This arrangement is chosen because at 8 mixer shafts, the axial conveyance of the shaft ring at half a turn is 3 gears, so that the overflow hole is about 3 gears apart from the mix level and is therefore reliable.

The direction of rotation 3 u of the mixer shafts determines the direction of rotation of the outer and inner shaft rings 1 u and 2 u, so that the location of the inner inlet bore 2 c thus automatically results.

The collection channel 9 b for the processed material, which is arranged unusually for screw machines, has the advantage according to the invention that the inlet bore 2 b can be arranged in its center not only in a simple manner, which opens into the radial, inner inlet bore 2 c and the inner worm ring supplied with mixed material, but, if necessary and the mixer should be temperature-controlled, the possibility of accommodating either inlet and outlet bores for tempering liquid or heating elements with their power supply lines and thermocouples around the melt channel.

The type of training of the mixer according to the invention at this point only enables the defined material supply to the inner rim of the Mixer shafts and is therefore a prerequisite for the exact addition tion of the partial flows to the mixer shafts and the longitudinal mixing of the components in the mix.

The inner housing 2 is just at its outlet end if rotatable with involute teeth 2 d and lagezen triert out against the lower end plate, which in turn is fixed by means of dowel pins 7 and screws 8 to the outer Ge housing or screwed.

Subsequently, the inner housing 2 is provided with a fine winch 2 e, so that with the lock nut 11 , between the inner housing and the lower end plate, a Montageein unit is created and the axial forces of the mixer can be absorbed.

The outlet-side sealing of the mixer takes place with the O-rings 12 a, 12 b, 12 c, 12 d, which can be made of perfluoroelastomer at higher working temperatures.

Because of the required tilt stability, the mixer stands on 4 feet 13 , which are screwed into position with the holding plate 10 . In order to facilitate the insertion of the mixer onto the base plate 14 and additionally to precisely define the process part for the distribution gear, guide grooves 14 a are provided in the base plate, which are provided on the insertion side with the conical extensions 14 b for easy finding of this groove.

With the base plate 14 are 3 handrails 15 screwed in position, the task of which is not only to carry the transfer case at a defined distance and align it to the process part, but also to enable it to be lifted around the process part for the purpose of installing other mixer shafts or maintenance work to be able to take out.

Claims (7)

1. Screw machine for mixing, coloring and homogenizing viscous masses with an outer and an inner housing, which are arranged coaxially to one another, with a plurality of conveyor mixing shafts, the axes of which are distributed parallel to the longitudinal axis of the housing evenly on the circumference of a circle, fixed between the outer and the inner housing are arranged, wherein an outer mixing space is formed between the outer housing and the conveyor mixing shafts and an inner mixing space is formed between the inner housing and the conveyor mixing shafts, which can be driven in the same direction of rotation, of which adjacent conveyor mixing shafts mesh with one another and each other and the enclosures enclosing them scrape off, the characterized with a first material feed through at least one bore (1 a, 1 b) in the region of one end of the outer casing in the outer mixing chamber and having a material outlet for the mixture in the area of the other ends of the housing as a second material feed (b 2 2 c) by minde least one bore is provided in the region of one end of the inner housing into the interior mixing chamber and that the bores (1 a, 2 c) in the same region of the outer or inner housing are located. 2. Screw machine according to claim 1, characterized in that the material outlet starts from an annular collecting channel ( 9 b) which is in flow connection with the outer and the inner mixing space. 3. Screw machine according to claim 2, characterized in that the flow connection between the outer and inner mixing chamber to the collecting channel ( 9 b) via holes ( 9 a) in the outlet-side end wall ( 9 ), which lie in the axis of the mixer shafts. 4. Mixer according to claim 1 to 3, characterized in that the outer and inner wave ring with separate Partial quantities are fed, their relationship to each other two-start snails behaves like 5: 1, 6: 2, etc. so the sum of these ratios is the number of waves results, however, in the case of three-flight snails like 9: 3, 11: 5 etc. behaves and only half the sum of these ratios nisse corresponds to the number of waves. 5. Mixer according to claim 1 to 4, characterized in that the inner housing ( 2 ) at least on one end by an involute toothing ( 2 a) with the housing end plate ( 6 ) is designed to be non-rotatable and position-centered. 6. Mixer according to claim 1 to 5, characterized in that a maximum of 3 screw flights below the upper screw start, the hole for the material inlet ( 1 b) to the outer ring and 180 ° opposite a material overflow hole ( 1 a) on the outer housing, and at the same height on the inner housing ( 2 ) opposite the material inlet for the outer ring, a separate material inlet ( 2 c) for the inner ring of the mixer shaft ( 3 ) is arranged. 7. Mixer according to claim 1 to 6, characterized in that as a metering device, a speed-controlled gear pump is used, whose tooth widths are like those to be conveyed Sub-sets behave, both gear pairs a common one Have inlet and two separate outlets, the Gears on the outlet side by an intermediate one Housing washer are separated from each other.