GB2120566A

GB2120566A - Dispersing or emulsifying apparatus

Info

Publication number: GB2120566A
Application number: GB08312057A
Authority: GB
Inventors: Viktor Press; Herbert Burkhard
Original assignee: Janke & Kunkel Co KG GmbH
Current assignee: Janke & Kunkel Co KG GmbH
Priority date: 1982-05-28
Filing date: 1983-05-03
Publication date: 1983-12-07
Also published as: FR2527474A1; IT8320809A0; DE3220092A1; IT1161822B; GB8312057D0

Abstract

In such an apparatus wherein a rotor (1) sucks in liquid axially and flings it out radially through slots (5) formed in a stator ring (2), so subjecting the particles in the liquid to substantial shearing and resultant comminution, the width of the slots (5) of the stator (2) or slots (4) formed in the rotor (1) is adjustable. In the embodiments, shown, a ring (9), rotatable with respect to the stator (2), has teeth (11) which can cover the stator slots (5) to a greater or lesser degree. Ring (9) may be rotated by means of knob (15) acting via an eccentric (14) on a projection (13) on ring (9) (Fig. 5). <IMAGE>

Description

SPECIFICATION Dispeersing or emulsifying apparatus The invention relates to a dispersing or emulsifying apparatus or the like having at least two tool rings rotating relative to each other, preferably having at least one rotor rotating at high speed and a fixed stator, the tool rings being arranged at a small spacing from each other and comprising slots or similar openings leading radially outwards.

Dispersing or emulsifying apparatus of this kind have long been known. Generally, a rotor rotates inside a stationary stator, at a small spacing therefrom. The rotor sucks in the medium in an axial direction and flings it radially outwards through its own slots and the slots in the stator.

The stator teeth which define these slots act as impact surfaces and the narrow gap between the rotor and stator produces considerable shearing effects. Particles which pass through the stator may generally be, at most, the same size as the width of the slots in the stator. As a result of the mechanical comminution, after a sufficient period of operation, almost all the solid constituents in the medium are, with statistical probability, reduced to a particle size which is somewhat smaller than the width of the slots in the stator.

In the past, in order to disperse a medium having relatively coarse constituents, it has been necessary either to use a multi-stage system with a relatively coarse stator, a medium stator and a fine stator or eise to change the rotors and stators in stages.

The aim of the invention is to provide a dispersing apparatus of the kind mentioned above wherein an end product with the desired degree of fineness can be obtained without changing the stator and without a multi-stage and therefore energy-consuming construction.

To achieve this, in a dispersing apparatus of the kind mentioned above the width of the slots of at least one tool ring is made adjustable. It is particularly advantageous if the width of the slots is infinitely adjustable. One arrangement which is particularly simple in construction and easy to produce and which is of considerable importance to the invention consists in the fact that the slots in the stator which preferably embraces the rotor on the outside are variable in width. Since the stator is stationary, particularly good adjustment is possible therewith.

The stator may comprise a coaxial ring or other component having slots, which is rotatable and capable of being fixed in position relative to the stator. In this way the width of the slots in the stator may be varied particularly easily, namely by rotating this coaxial ring to a greater or lesser extent. As a result its slots coincide more or less with the slots in the other part of the stator.

The rotatable part may have as many slots as the stator and the areas between these slots may serve as slides for at least partially and variably closing off the slots in the stator.

Another embodiment which is also favourable from the point of view of production is obtained if the rotatable part has a ring or the like preferably encircling the end face of the stator at least partially, and has teeth or the like axially arranged thereon for adjusting the effective aperture size of the stator slots. The ring may be rotatably mounted on the end face of the stator and the teeth pointing away from the end face then form the above mentioned slide-like closing flaps for the stator slots.

The teeth or the like of the rotatable part may engage in grooves in the stator which are open in the circumferential direction towards a stator slot, the radial depth of these grooves preferably corresponding substantially to the radial thickness of the teeth, whilst the edge of the slots opposite the groove in question forms an abutment for the teeth in the direction of rotation. In this way a stator is obtained wherein the rotatable part is mounted practically in the contour thereof and wherein, in the open position, the teeth are located in the grooves and leave the slots open, whereas in the other extreme position there are rotated up to the edge of the slots remote from the grooves. The width of the teeth is, of course, at least equal to the width of the slots, so that in this extreme position the slots are practically closed off.Thus, an adjustment of several tenths or even only one tenth of a millimetre is possible. At the same time, the width of the teeth on the rotatable part may correspond to the width of the groove outside the stator teeth in question so that in the open position the full slot width is obtained.

The rotatable part may project coaxially into the interior of the stator. In the above mentioned embodiment with grooves for receiving the teeth of the rotatable part, an additional advantage is thereby obtained by virtue of the fact that, with a partially reduced slot width, the grooves are partly opened up at the same time and additional vortex chambers are produced between the rotor and stator.

However, in some cases, it is advisable for the rotatable part to be mounted on the outer circumference of the stator. It is then more accessible, particularly to permit adjustment.

The rotatable part may be connected to a rotational spindle or the like mounted on the stator clamp or on the stator shaft. The rotational spindle may be capable of being fixed in position by means of a clamping device, particularly a clamping screw or the like. However, it is also possible for the rotatable part to be fixed to an outer sleeve, in an arrangement which surrounds the stator on the outside, this sleeve engaging around the stator shaft or the like and being rotatable and capable of being fixed relative to this stator shaft. Fixing may also be effected using clamping means.

In addition to or instead of the arrangement of actuating members for the rotatable part, this part may be force-fitted relative to the stator. This will enable it to be adjusted directly or by means of a sleeve or the like acting upon it, in certain circumstances, without the need for any special securing means to maintain the selected position.

The ring of the adjustable stator part and/or the end face of the stator itself may bear or form a flange which projects radially inwards and which prevents the medium from escaping axially from the gap between the rotor and stator.

In particular, if one or more of the measures and features described above are combined, a dispersing apparatus is obtained which will produce a fine dispersion even if the solid constituents of the medium have a large particle size to start with. There is no need to replace the tool rings nor is there any need to provide multistage tool rings; all that is required is to reduce the width of the slots, more particularly in the stator, more and more as the operation progresses.

Eventually, a slot width can be achieved which was impossible to obtain with conventional stators, since slot widths of the order of one-tenth of a millimetre can be achieved on the stator.

In order that the invention may be readily understood certain embodiments thereof will now be described by way of example with reference to the accompanying drawings, in which: Fig. 1 is a cross-section and Fig. 2 is a longitudinal section through two tool rings in a dispersing apparatus having an inner rotor and an outer stator, Fig. 3 is a cross-section and Fig. 4 is a longitudinal section through the rotor and stator of a modified embodiment of the dispersing apparatus, Fig. 5 is a longitudinal section through a continuously operating throughflow apparatus and Fig. 6 is a longitudinal section through a modified embodiment which is preferably provided in a batch-type apparatus.

Two tool rings rotating relative to each other, namely a rotor 1 and stator 2, are provided for a known dispersing apparatus or the like, which is not shown in the drawings, for the sake of clarity.

The rotor 1 may be secured to a rotor shaft in known manner by means of the internal thread 3.

The two embodiments by way of example in Figs.

1 and 2, on the one hand, and Figs. 3 and 4, on the other hand, differ only in the shape of the rotor 1. In both cases, the medium sucked in at the end in the direction of the arrow Pf 1 is flung outwards through radial slots 4 when the rotor rotates, for example in the direction of the arrow Pf 2. As a result the medium is forced to flow through the slots 5 in the fixed stator as well. Any solid particles are broken up both in the gap 8 between the rotor 1 and stator 2 and also in these slots 5.

According to the invention, the width of the slots 5 in the stator 2 is adjustable so that the slots 5 can be made progressively narrower in the course of the dispersing operation so as to make the solid particles smaller and smaller. It is possible to reduce the slot width to a size of the order of one-tenth of a millimetre, which is impossible with a one-piece stator.

In all the embodiments shown, the stator 2 has a coaxial ring 9 as its rotatable part which is in turn provided with slots 1 0. This ring 9 is rotatable and capable of being fixed relative to the stator 2, so that the degree of overlapping of the slots 5 and 10 can be varied. This is a particularly simple method of adjusting the slot width of the stator 2.

The rotatable part 9 has as many slots 10 as the fixed part of the stator 2 and the spacings 11 between the slots 10, which are hereinafter also referred to as teeth, act as slides for partially and variably closing off the slots 5 in the stator Figs. 1 to 5 show that the rotatable part 9 has a terminal ring 12 encircling the end face of the stator 2 and on this ring the above-mentioned teeth 11 for adjusting the effective aperture size of the stator slots 5 are axially mounted.

If desired, an adjustment can be made using this terminal ring 12, as shown in Fig. 5, for example. In Fig. 5 an eccentric 14, which can be rotated by means of the handwheel 1 5, engages on a projection 1 3 of the rotatable ring 9 or terminal ring 12. Its eccentricity is sufficient for the relatively slight rotary movement of the ring 9 required.

In the embodiment shown in Figs. 1 and 2, the teeth 11 of the rotatable part 9 engage in grooves 1 6 in the stator 2, these grooves 1 6 each being open in the circumferential direction towards a stator slot 5, whilst the radial depth of the grooves 1 6 corresponds substantially to the radial thickness of the teeth 11. The edge 1 7 of the slots 5 located opposite the groove 1 6 in question forms an abutment for the teeth 11 in the direction of rotation. In this embodiment, the width of the teeth 11 corresponds to the width of the groove 1 6 outside the stator slots 5 in question and even exceeds the width of the stator slots 5 themselves.Thus, in the open position, the entire cross-section of the slots is left open, whilst these slots can be made narrower as desired by lateral rotation of the teeth 11. Fig. 1 shows a middle position of rotation. Here, the edge portions of the grooves 16 remote from the slots 5 in question are partially open, so that individual vortex chambers open up to give an even better dispersing effect.

In the embodiments shown in Figs. 1 to 4, the rotatable part 9 projects coaxially into the interior of the stator 2. Figs. 5 and 6 show an arrangement wherein the rotatable part 9 is mounted on the outer circumference of the stator 2. This depends on the embodiment of the actual apparatus in which the dispersing apparatus according to the invention is to be used.

The embodiment shown in Figs. 1 to 4 is a dispersing apparatus wherein the tool rings can be immersed in a container of fluid. Fig. 5 shows a continuously operating throughflow apparatus wherein the medium may again be fed in in the direction of the arrow Pf 1. The rotor is carried by a drive shaft 1 8 which is mounted in suitable bearings. The stator 2 is located in a housing 1 9.

The adjusting device comprising a handwheel 1 5 and the eccentric 14 for the rotatable part 9 of the stator 2 has already been described.

Figs. 3 to 5 also show that the terminal ring 12 of the adjustable part 9 of the stator or, possibly, the end face of the stator 2 itself bears or forms a flange 20 which projects radially inwards. This prevents the medium from escaping from the apparatus axially or at the ends, particularly if the slot width is very small.

Fig. 6 shows an arrangement which is preferably for use in a batch-type apparatus, wherein the rotor 1 is again carried by a shaft 18 in a vertically downwardly suspended arrangement. The rotatable part 9 embraces the stator 2 from the outside and is secured to an outer sleeve 21 which surrounds the stator shaft 22 and can be rotated and secured relative thereto. Again, the medium enters the apparatus 1 axially from below, in the direction of the arrow Pf 1, and leaves the apparatus in the radial direction through slots 5 which are adjustable in width.

Since the slot width, particularly on the stator of a dispersing apparatus, is adjustable, this apparatus can be used for dispersing even coarse components in the substance in question, without any need to change the tool rings and without using a multi-stage system.

All the features and details of the construction appearing in the specification, abstract, claims and drawings may be essential to the invention both individually and in any desired combination with one another.

Claims

1. Dispersing or emulsifying apparatus comprising at least two tool rings rotatable relative to one another and arranged at a small spacing from each other and comprising slots or similar openings leading radially outwards, in which the width of the slots of at least one of the rings is adjustable.

2. Apparatus as claimed in claim 1, in which the width of the slots is infinitely adjustable.

3. Apparatus as claimed in claim 1 or 2, in which the width of the slots of the stator ring which surrounds the rotor on the outside is adjustable.

4.' Apparatus as claimed in claim 1, 2 or 3, in which the stator ring has a coaxial ring or similar component comprising slots, which is rotatable and capable of being fixed relative to the stator.

5. Apparatus as claimed in claim 4, in which the rotatable component has as many slots as the stator ring and the spacings between its slots act as slides for at least partially and variably closing off the stator slots.

6. Apparatus as claimed in claim 4, in which the rotatable component has a ring or the like which preferably encircles the end face of the stator at least partially and teeth or the like axially mounted thereon for adjusting the effective aperture size of the stator slots.

7. Apparatus as claimed in claim 6, in which the teeth or the like of the rotatable part engage in grooves in the stator, each of which is open in the circumferential direction towards a stator slot, the radial depth of the grooves corresponding substantially to the radial thickness of the teeth, whilst the edge of the slots which is located opposite the groove in question forms an abutment for the teeth in the direction of rotation.

8. Apparatus as claimed in claim 6 or 7, in which the width of the teeth of the rotatable part corresponds to the width of the groove outside the stator slots in question and/or to the width of the stator slots.

9. Apparatus as claimed in any of claims 4 to 8, in which the rotatable part projects coaxially into the interior of the stator.

10. Apparatus as claimed in any of claims 4 to 8, in which the rotatable part is mounted on the outer periphery of the stator.

11. Apparatus as claimed in any of claims 4 to 10, in which the rotatable part of the stator is connected to a rotational spindle or the like mounted on the stator clamp or on the stator shaft.

12. Apparatus as claimed in claim 1 in which the rotational spindle or the like can be fixed in position by means of a clamping device.

13. Apparatus as claimed in one of claims 4 to 12, in which the rotatable part is force-fitted relative to the stator.

14. Apparatus as claimed in of claims 6 to 8, in which the terminal ring of the adjustable stator part and/or the end face of the stator itself bears or forms a flange which projects radially inwards.

1 5. Apparatus as claimed in one of claims 4 to 14, in which the rotatable part, in an arrangement surrounding the stator from outside, is secured to an outer sleeve which embraces the stator shaft or the like and is rotatable and capable of being fixed relative thereto.

16. Apparatus as claimed in one of claims 4 to 15, in which an eccentric or the like engages on a projection of the rotatable ring.

17. Dispersing or emulsifying apparatus substantially as hereinbefore described with reference to any of the accompanying drawings.