DE19607664A1 - Multi=shaft screw machine for processing viscous materials and distributor drive for machine - Google Patents

Abstract

A multi-shaft screw machine with a distributor drive for mixing, pigmenting and homogenising viscous fluids and solids comprises two coaxial housings (1, 2) between which and around whose common axis parallel mixing screws (3) are arranged and closely intermesh with each other. Material for processing is supplied to the outer and inner rims of the screws (3) by separate opposing bores (1a, 2c) in the housings (1, 2) and the material outlet from each screw is via a bore (9) along the axis of each screw, each bore entering a collecting channel (9a) with a cross-section which increases from screw to screw and which continues axially or radially out of the machine at the point of largest diameter. The material feed channel (2b) to the inner housing (2) passes through the centre of the collecting channel(9a). A claimed distributor drive for the machine comprises a central shaft driving pinion shafts with coated end caps which under axial loading press against a coated thrust plate rotating with the drive shaft and supported on a thrust bearing coaxial with the latter.

Description

The invention relates to a vertical, multi-wave Screw machine for mixing, coloring, homogenizing viscous liquids and masses, with a fixed one Housing, in the longitudinal axis in a fixed ring with closely arranged conveying mixing shafts little rotating, parallel to the axis and interlocking, with their Surfaces each other and with their combs so that they are tight Game enveloping or the housing enveloped by them forcibly scrape off.

Such mixing machines, regardless of the con principle of construction they work, have the common disadvantage that they are only suitable for Gargenbetrieb and the size of the Garge the mixer determined in volume, such Batch mixer for continuous operation is therefore unsuitable are suitable because the mixing process is not a constraint at the same time current, defined mass transfer 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.

The present invention has set itself the task of To create mixers, which are suitable for both batchwise and is also suitable for continuous operation, the cleans itself and despite its small machine volume mens, is also able to process extremely large batches.  

To solve this problem is the mixer mentioned at the beginning characterized in that the metered material feed for the outer and inner ring of the mixer shafts opposite each other horizontal, separate bores in the housings assigned to them and the material discharge from a ring-shaped collecting box nal runs out, within which the inlet channel for the inner Wreath of mixer shafts is arranged.

According to the invention, such a mixer works, for example 8 mixer shafts such that first the mass transfer process in the mixer necessarily because the mixer shafts are provided with a sealing profile, which for a compulsory wise transport of the mix in 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, will continue 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 in each Relationship has more optimal properties.

Tests have shown that the outer ring of shafts with 8th Mixer shafts and one turn of the ring, i.e. 2 turns of Mixer shafts, axial 6 gears and the inner shaft rim at One turn only promotes 2 gears, 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 material wreaths superimposed, axially mixed intimately, so that quantitative concentrations of individual components in the Ver work well balanced and complete color uniformity is achieved in the mix.  

This results in a radial mixing of the material to be processed forced - especially with wetting products - that in the gusset area of the sealing profile of the screws, double the circumference speed is effective, especially since the screw surfaces at this point turn opposite to each other so that over the outer ring is supported - for example with 8 waves moved at 3 times the axial speed in relation to the inner ring, so that it was previously unknown in screw machines Longitudinal mixing is achieved and so mixing components collections can be dissolved, which is a prerequisite to achieve a consistently homogeneous mix.

The mixer is therefore preferred with a two-start seal profile equipped because with a catchy sealing profile the axial crown overlap is completely absent, but one is three-course sealing profile is still three times the rim coverage available, but then the mixer would have to be short longer dwell time, which is uneconomical.

Since such batch batches can be several cubic meters in size, it is useful, with the same recipe and different colors, the approach to produce without color and the color solution directly to Feed mixer by means of additional metering device, whereby the color change is done by switching the new color is fed to another dosing device and the dunk the lighter color follows the lighter one.

If different viscosities are to be mixed together it is expedient to separate these depending on the two wave rings ability to pump in metered amounts to each other and the material to be processed to feed a third container, the material outlet of which is just if formed by a metering device, so that the mixing good until a certain mix quality is reached, several times in Cycle can be driven.

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 does not change with a mixer.

For certain applications it is also possible to use the inside wreath of mixer shafts over the outer rim ken that the processed goods through the gusset area of the Mixer shafts is pushed through, which is an essential Lich requires higher feed pressure and leads to the fact that the removal of the outer inlet bore from the upper screw conveyor ginn, must be increased and the pressure difference between Radial pressure from outside and inside on the outside Mixer shaft generated, so that this leads to this before mentioned distance is viscosity-dependent and therefore on a Mixer, which is designed for low viscosities, none higher viscosities can be processed, or these Working method can only be used with very low viscosities.  

The device according to the invention is illustrated by drawings poses. Show it:

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

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

Fig. 3 shows a longitudinal section through the transfer case of the mixer on the same scale, without reduction gear and drive motor.

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 rim, and the inner Zulaufboh tion 2 c for the inner shaft rim can be seen, which are at the same height to the upper end plate with about 3 gears net angeord . 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 ver, the task of which is not only to carry the transfer gear 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 To be able to take out maintenance work or to lower it in a defined manner for the assembly of the couplings, each height position must be self-locking for safety reasons, which will be explained in more detail later.

The illustrated in Fig. 3 without motor and reduction gear distributor 16 , consists of the upper connection housing 17 , the bearing plates 18 , 19 , the intermediate plate 20 and the lower sealing plate 21 , which are fixed and screwed together via dowel pins 22 and the screws 23 . All housings are sealed to one another with the same size O-rings 24 .

In the bearing plates, the same needle bearings 18 a, 19 a are provided, which receive the pinion shafts 22 , 23 with their axially offset toothings and are driven by the central shaft 25 , the radial bearing of which is supported by 2 identical needle bearings 25 a, 25 b and a third needle bearing 17 c is taken over. Because of the small center distances of all shafts to each other, all rolling elements run on the shaft surfaces, so that these raceways are also coated with chromium oxide, although other layers, following technical progress, may also be possible.

At the drive end of the pinion shafts a right-handed fine thread 22 a corresponding to the direction of rotation of these shafts is provided for receiving the chromium oxide coated end caps 22 b, which transmit the axial forces of the pinion shafts to the pressure plate 25 d driven by the central shaft, which are transmitted to the thrust bearing 25 e and the flat surface 17 c supports.

At the non-driven end of the central shaft a further pressure bearing 25 f is arranged, which is biased by the coil springs 21 a. This biasing force is transferred via the split ring 25 g to the pressure plate, which also prevents it from falling out. Thus, the thrust bearing 25 e is under a biasing force generated by the coil springs 21 a, which is of crucial importance for the life of this bearing and the function of the axial bearing of the pinion shafts. The supply of lubricant to the running surfaces of the end caps is ensured because the driven pressure plate moves relative to the end caps.

The driven end of the central shaft is provided with involute teeth 25 h, which drives the likewise coated inner ring 25 i of the needle bearing 17 a and the pressure plate 25 d. The axial bracing of the inner ring 25 i with the pressure plate 25 d compared to the split ring 25 g take over the conical studs 25 l in cooperation with the conical recess 25 k.

In order to fix the pinion shafts with little axial play when the transfer case does not rotate axially with respect to the pressure plate, a left-hand fine thread 22 c is provided on the output side of the pinion shafts for receiving the bearing bushes 22 d coated on the end face, which bear against the coated flat surface of the sealing plate 21 and stand out immediately as soon as the transfer case rotates and axial pressure is built up by the mixer shafts in order to overcome its own weight.

At the output ends of the pinion shafts are mirror image Lich the same involute teeth 22 e and conical grooves 22 g for receiving and axially fixing the shaft couplings 3 c, as on the mixer shafts.

The transfer case 16 is provided on both sides with radial shaft seals 21 b and 17 b, the sealing surfaces of which are also coated and polished in order to achieve a corresponding service life and tightness of these sealants.

The upper end of the 3 support rods 15 is carried out with a flat thread 15 a for receiving the pinion 15 b provided with the same counter thread, which is arranged via an internally toothed intermediate ring 15 c, from a not shown and between the lower sealing plate 21 and the intermediate plate 20 Pinion shaft, can be turned using a commercially available 1/2 inch ratchet wrench.

When the transfer case is lowered, the pinions 15 b rest with their lower end faces on the flat surfaces 15 d and the transfer case is supported with the flat surfaces 20 a of the intermediate plate 20 on the thrust bearing 20 b, which forces these via the centering ring 20 c on the upper flat surface, the pinion 15 b transmits, so that the exact height of the end faces 22 f of the pinion shafts relative to the end faces 3 f of the mixer shafts and the lower game 26 of the mixer shafts relative to the lower end plate 9 and its upper game 27 opposite the upper end plate 6 is ensured.

When lowering the transfer case, thread the fitting bolts 6 c of the upper end plate into the fitting holes 21 c of the lower sealing plate, the task of which is not only to bring both assemblies into precise axial alignment, but also the counter torque from the process part into that To direct transmission.

The part inserted when the transfer case is raised includes the shaft couplings pushed onto the mixer shafts without studs 3 c. Since the shaft couplings each have 4 symmetrically arranged threaded holes on the circumference, it must be ensured when pushing on that 2 opposite threads each point with their axes parallel to a mixer axis.

Before the final push on of the couplings is special to ensure that all involute gears let it move easily. It has proven to be beneficial proved to number the couplings so that they always on the same place and the same partner area find Chen.

Now the transfer case is slowly lowered until the end faces 22 f reach the end faces of the clutches. Nevertheless, to make assembly easier both end faces of the involute teeth are pointed so that they can be easily snapped in, it is not possible to insert all the couplings together into the involute teeth 22 e of the pinion shafts at the same time, since the mixer shafts, despite the slight play of their sealing profile, are slightly twisted towards each other can, so that the small tooth spacing of the involute toothing is not sufficient to make this possible.

Therefore, it is much easier to lift each shaft coupling individually and move it back and forth with the mixer shafts until the involute gears grasp and then fasten with a conical stud screw in the upper thread 3g in the conical groove 22 g of the pinion shafts. After all the shaft clutches hang on the transfer case, it is lowered a little. In this state, both involutes are in alignment and coupled with each other, so that the studs can be removed from all shafts again, and the two dowel bolts 6 c are inserted into their partner holes and both assemblies are rotatably connected, aligned.

After the transfer case is in its operating position, the lock nuts 15 e are tightened so that the axial pressure of the mixer shafts cannot lift it up via the pinion shafts.

Claims (10)

1. Vertical, multi-shaft screw machine for mixing, coloring, homogenizing viscous liquids and materials, with a fixed housing, in the longitudinal axis of which in a fixed ring arranged mixing shafts rotating in the same direction, parallel to the axis and interlocking, each other and the enveloping or scrape the housing they sheathed, characterized in that the metered material inlet for the outer and inner ring of the mixer waves takes place over opposite, separate bores in the housings assigned to them and the material outlet starts from an annular collecting channel, within which the inlet channel for the inner Wreath of mixer shafts is arranged. 2. Mixer according to claim 1, characterized in that the outer and inner wave ring with separate subsets is loaded, their relationship to each other in two-course Snails behave like 5: 1, 6: 2 etc., so that the Sum of these ratios gives the number of waves, however in the case of three-speed snails, 9: 3, 12: 4 etc. holds and only half the sum of these conditions, the waves number corresponds. 3. Mixer according to claim 1 and 2, characterized in that the Inner housing on both ends via involute gears with the two housing end plates torsion-proof and position-centered is trained. 4. Mixer according to claim 1 to 3, characterized in that the Transfer case with drive after uncoupling the mixer shaft len can be raised and after the guide pins are released Recording the counter torque, the entire process part can be removed laterally. 5. Mixer according to claim 1 to 4, characterized in that a maximum of 3 screw flights below the upper screw fangs, the hole for the material feed to the outer ring and  180 ° opposite a material overflow hole on the outside housing, as well as at the same height on the inner housing opposite own material for the outer wreath rial inlet arranged for the inner ring of the mixer shafts is. 6. Mixer according to claim 1 to 5, characterized in that the axial forces of the mixing shafts above that of a Zen tralwelle driven pinion shafts and their coated End caps, on a driven by the central shaft, coated printing plate, which can be transferred supports a thrust bearing arranged coaxially to the central shaft. 7. Mixer according to claim 1 to 6, characterized in that its shaft couplings approximately in the middle, with two rows conical, radially arranged studs are provided, which in conical ring grooves of the two shafts to be coupled engage ends to axially chuck the shafts to each other and for mounting these couplings, on the pinion shaft side another threaded hole to accommodate the same Stud screw is arranged. 8. Mixer according to claim 1 to 7, characterized in that whose height-adjustable transfer case turned on in each provided its altitude self-locking holds. 9. Mixer according to claim 1 to 8, 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. 10. Mixer according to the preamble characterized in that the inner rim of the mixer shafts over their outer rim is supplied by means of overpressure in the processed goods.