EP0510256B1 - Method and apparatus for crushing, dispersing, wetting and mixing of pumpable, non-magnetic multiphase mixtures - Google Patents

Abstract

Apparatus for crushing, dispersing, wetting and mixing pumpable, non-magnetic multiphase mixtures consists of a sealed-off annular gap chamber 1 whose annular gap forms a working chamber into which the material to be processed flows from below and flows out from the top. This annular gap chamber is formed by a double pipe whose outer pipe is surrounded by an outer exciter system 4 and whose inner pipe is surrounded by an inner exciter system 5. In the working chamber, in addition to the material to be processed, there are freely movable magnetic working bodies 7 which move inside the multiphase mixture, flowing through the annular gap chamber 1 in the direction of the circulating electromagnetic fields, and carry out translatory transverse movements and rocking movements. Inside the working chamber, or the annular gap, there is a flowing-in zone 13 and a flowing-out zone 14 which are each free of working bodies. <IMAGE>

Description

The invention relates to a method for comminuting, dispersing, wetting and / or mixing pumpable, non-magnetic multiphase mixtures by means of electromagnetic energy which acts on magnetic working bodies within substances in a closed volume, the working bodies moving differently under the influence of an electromagnetic field and the multiphase mixture is surrounded on two sides by two mutually opposed, self-contained excitation systems, each of which generates an electromagnetic field that rotates in the same direction, penetrates the multiphase mixture in one direction, and changes tangentially around the volume of the multiphase mixture between the opposing pathogen systems.

When processing materials by crushing, in particular by fine and very fine crushing of granular substances, and / or by mixing, dispersing and / or stirring powders, liquids and gases, the focus is on the fact that the largest possible contact surface or surface of the interacting Phases must be generated because this shortens the processing time and reduces the temperature and concentration gradient in the processing volume.

For the procedural steps, such as comminution (deagglomeration), dispersion, wetting and mixing of pumpable non-magnetic multiphase mixtures, it is known that agitator ball mills in various technical designs are used.

With this processing technology, the energy used is only indirectly transferred to the multi-phase mixtures via several intermediate stages, starting with the electric drive, via a rotating agitator and one or more grinding media. This results in high energy losses, which have to be dissipated as thermal losses via complex cooling systems.

Furthermore, on the material discharge side of the working space for the grinding media, additional separation devices, such as screens, gap filters, etc., and shaft sealing systems are required, which are exposed to high material wear.

Devices and methods for mechanically processing granular substances and / or for mixing and stirring powders, liquids and gases using electromagnetic fields are also known. Here, the electrical energy supplied to a stationary main element is converted directly into mechanical energy of freely movable ferromagnetic working bodies by means of electromagnetic fields. The stationary main element is, for example, an electrical excitation arrangement which carries an excitation winding and which has an air gap space.

From the patent specification DD-A1 - 240 674 a method of the type described in the introduction and devices for carrying out the method are known. In these devices, the comminution, mixing and stirring of powders, liquids and gases, in particular of granular substances, takes place on the basis of the direct electromechanical energy conversion with the aid of moving electromagnetic fields. For this purpose, a plurality of excitation system parts which are hermetically limited in the direction of movement of the electromagnetic field are put together to form an excitation arrangement with gap distances. The excitation system parts can be flat, rectilinear and / or flat, curved parts that go to that in itself closed and located in a surface exciter arrangement are assembled. The electromagnetic field of this excitation arrangement penetrates a closed working chamber which is arranged in the gaps between the excitation system parts. Magnetic working bodies and the substances to be processed are located in the working chamber. In the known method, the movement of the multiphase mixture takes place parallel to the direction of movement of the working bodies, which can result in uneven distributions of the working bodies in the multiphase mixture, as well as lower relative movements between the working bodies and the multiphase mixture, which significantly reduce the treatment effects.

In addition, due to the above-mentioned multi-phase mixture guidance, such an exciter arrangement is only suitable for the dry fine and very fine comminution of granular material, but not for the mechanical preparation of pumpable multi-phase mixtures.

From DE-OS 25 56 935 a material processing method for powders, liquids, gases and their mixtures and a device for carrying out the method is known, in which the material to be processed is introduced into a chamber together with magnetic elements made of hard magnetic material, which are under the influence of an alternating electromagnetic field move chaotically. The alternating field is generated by means of an electrical excitation winding in a room in which the chamber is arranged. The field winding surrounds the chamber. The magnetic elements are arranged in the chamber in a layer of a predetermined thickness, this being determined by the operating conditions of the magnetic field, the size of the magnetic elements, their density and their magnetic sizes, such as induction and coercive force, and by gravity.

In other material processing methods, as described in US Pat. Nos. 3,219,318 and 3,423,880, hard magnetic ferromagnetic elements and alternating magnetic fields, in particular pulsating magnetic fields, are used.

In this method, the machining material of any shape is first introduced into a chamber and then the ferromagnetic elements made of a hard magnetic material. The chamber is then brought into a room in which an alternating magnetic field is generated. The magnetic field sets the ferromagnetic elements in a chaotic movement, in which they rotate about their axes and collide with each other, whereby the material is processed accordingly.

In the methods according to the cited patents, the magnetic elements are made of a hard magnetic material with a coercive force above 50 Oe and have a non-spherical shape. Their average size is in the range of at least a few tenths of a micrometer up to a maximum of 2.5 cm. The magnetic field strength of the alternating field is over 0.01 Oe and its frequency up to 1 MHz.

These processes are used to process substances in a periodic and uninterrupted operating sequence in small vessels, boxes, tubes or capillaries as well as for grinding difficult to access surface areas.

The devices with which the above-mentioned working methods are implemented contain an electric solenoid winding and a working chamber made of a non-magnetic material, arranged in the inner and outer space of the solenoid coil, in which a sinusoidal alternating magnetic field is generated. The magnetic elements made of barium hexaferrite or an "Alnico-8" alloy or iron-cobalt-nickel-aluminum alloy of indefinite shape introduced into the chamber, through their movements under the influence of the magnetic field, cause the machining material to be mixed or comminuted. The number of magnetic elements in the chamber is chosen so that they are sufficiently far apart from one another during their movements in the chamber and do not wear one another, this number being less than the number of elements in their single-layer arrangement over the entire floor area the chamber.

A disadvantage of the known methods is the low energy density, which is caused by the relatively small number of magnetic elements per volume of the working chamber, which is introduced into the processing operations. As a result, large energy requirements arise because not the the entire volume of the magnetic field is used, per unit of the processed product, which increases the cost of material processing. It can be seen that an increase in the number of magnetic elements in the working chamber leads on the one hand to their high wear, whereby the processing product is contaminated and the processing costs increase due to the high consumption of the expensive magnetic bodies, and on the other hand the lower-lying magnetic elements move less intensely than the upper ones as a result of gravity acting on the underlying elements.

In the known processing devices, an air gap space is available as a work space. It contains a large number of ferromagnetic working bodies, which act in the conventional sense as grinding media, and the substances or multiphase mixtures to be processed.

• konzentrische Wechselfelderregersysteme mit einphasig gespeisten Ring- bzw. Solenoidwicklungen wie sie z.B. in den Druckschriften SU-PS 480 447 DE-OS 25 56 935 SU-PS 662 144 SU-PS 837 411 SU-PS 908 389 DE-OS 38 43 368 beschrieben sind,
• lineare ein- und zweiseitige Wanderfelderregersysteme mit mehrphasig gespeisten Strangwicklungen gemäß den Druckschriften SU-PS 995 221 SU-AS 102 3573 DE-OS 32 33 926 DE-OS 32 40 021 DE-OS 32 40 057 SU-AS 110 3887 und
• rotationsymmetrische ein- und zweiseitige Drehfelderregersysteme wie sie aus den Druckschriften DE-PS 888 641 GB-PS 15 70 934 SU-PS 808 146 SU-AS 10 45 927 DE-OS 32 33 926 DD-PS 240 674 bekannt sind.

Three different types are generally used for the excitation systems:

• Concentric alternating field excitation systems with single-phase fed ring or solenoid windings as described, for example, in the publications SU-PS 480 447 DE-OS 25 56 935 SU-PS 662 144 SU-PS 837 411 SU-PS 908 389 DE-OS 38 43 368 ,
• linear single and double-sided traveling field excitation systems with multi-phase fed phase windings according to the publications SU-PS 995 221 SU-AS 102 3573 DE-OS 32 33 926 DE-OS 32 40 021 DE-OS 32 40 057 SU-AS 110 3887 and
• Rotationally symmetrical single and double-sided field excitation systems as they are known from the publications DE-PS 888 641 GB-PS 15 70 934 SU-PS 808 146 SU-AS 10 45 927 DE-OS 32 33 926 DD-PS 240 674.

In alternating field excitation systems with single-phase fed ring or solenoid windings, the space enclosed by the winding is fully available as a work space for material processing. Ferromagnetic components are not required to guide the excitation field.

In contrast, however, there is initially the necessary additional use of winding material to ensure sufficient working area field strengths and problems in dissipating the current heat losses from the compact toroidal coils. The low heat transfer to the environment and the limited heat absorption capacity of the material flow always require additional measures for sufficient dissipation, which on the one hand ensures that the magnetic characteristics of the working bodies are not significantly reduced and on the other hand that the material to be processed does not exceed prescribed limit temperatures warmed up.

mit:

B̂ - Amplitude
f - Frequenz des Erregerstromes
t - Zeit

dar.Furthermore, the excitation field B (x, t) here is a pure alternating field $$\text{B (x, t) =}\widehat{\text{B}}\text{Cos (2πf t)}$$

With:

B̂ - amplitude
f - frequency of the excitation current
t - time

represents.

This means that at each location x of the work area only field changes of the same size take place. They can only bring about the same oscillating or rotating movements of the working bodies.

• der Arbeitsraum nahezu vollständig mit Arbeitskörpern gefüllt sein,
• bestimmte Gattierungen (Größe und/oder Form) der Arbeitskörper eingehalten werden und eine
• Gradierung in der radialen Feldstärkeverteilung vorhanden sein.

In order to ensure the relative movements between the working bodies that are absolutely necessary for the mechanical stressing of the substances to be processed

• the work area is almost completely filled with work bodies,
• certain genera (size and / or shape) of the working body are observed and a
• Grading should be present in the radial field strength distribution.

The high degree of filling of the working body limits on the one hand the essential dimensions of the processing device and thus the material throughput, since the gravity and adhesive forces of the working body fix their maximum dumping height (DE-OS 25 56 935). In addition to the critical dumping height of the working bodies, insufficient working body movements are achieved, especially in the lower areas. This results in a decrease in the energy input into the work area and a reduction in the machining effectiveness.

On the other hand, the high working body filling levels result in high working body wear due to the frequent working body collisions.

The required local field strength gradients are only possible radially inwards in the case of alternating field excitation systems. The field strength drops exponentially over the inner extent of the excitation system. As a result, the working body movement and thus the machining effectiveness radially inward is becoming less and less. This enables dead space areas in batch operation and bullets with continuous material replenishment.

Versions with ring and solenoid windings are limited to small diameter / length ratios and have low energy densities and low efficiency.

mit:

B̂ - Amplitude
τ_p - Polteilung der Erregeranordnung
f - Frequenz der Erregerströme

Das heißt, im Arbeitsraum liegt eine sinusförmige Induktionsverteilung vor, die sich mit konstanter Geschwindigkeit $${\text{v}}_{\text{o}}{\text{= 2τ}}_{\text{p}}\text{· f}$$

bewegt. Diese gesetzesmäßige Feldbewegung bewirkt einen Transport des ferromagnetischen Inhaltes des Arbeitsraums. Damit wandern die Arbeitskörper in kurzer Zeit zu einem der beiden Enden der Arbeitskammer, stauen sich hier und behindern sich gegenseitig in ihrer Bewegung. Dadurch vermindert sich merklich der mögliche Energieumsatz und der Wirkungsgrad. Es werden deutlich geringere und ungleichmäßige Aufbereitungseffekte erhalten. Um diesem Nachteil entgegenzuwirken, werden grundsätzlich zwei gegenüberliegende Wanderfelderregersysteme verwendet und zusätzliche Maßnahmen zur Verungleichmäßigung der Arbeitskörperbewegung realisiert:

• entgegengesetzte Schaltung der Erregerfelder der einander gegenüberliegenden Erregersysteme über die gesamte Erregersystemlänge (SU-PS 995221, DE-OS 3233926) oder abschnittweise (SU-AS 1023573, SU-AS 1103897),
• Änderung des Abstandes der einander gegenüberliegenden Erregersysteme über ihre Länge (DE-OS 3233926, SU-AS 1103897),
• Feldverungleichmäßigungen durch verschiedene Polteilungen, unterschiedliche Einspeisung und Dimensionierung der Erregerwicklungen der einander gegenüberliegenden Erregersysteme (DE-OS 3233926),
• Anbringen von Trennwänden im Arbeitsraum quer zur Bewegungsrichtung des Erregerfeldes (DE-OS 3233926).

The known linear traveling field excitation systems have a three-strand winding distributed in slots. A closed magnetic circuit made of laminated laminated cores is required to guide and ensure the penetration of the work area with the excitation field. The field of excitation changes not only in time but also in location. It applies to the fundamental wave: $$\text{B (x, t) =}\widehat{\text{B}}\text{cos (}\frac{\text{π}}{{\text{τ}}_{\text{p}}}{\text{x - 2π · f · t + ρ}}_{\text{B}}\text{)}$$

With:

B̂ - amplitude
τ _p - pole pitch of the excitation arrangement
f - frequency of excitation currents

This means that there is a sinusoidal induction distribution in the work area that is moving at a constant speed $${\text{v}}_{\text{O}}{\text{= 2τ}}_{\text{p}}\text{· F}$$

emotional. This legal field movement causes the ferromagnetic content of the work area to be transported. This means that the working bodies move to one of the two ends of the working chamber in a short time, jam here and hinder each other's movement. This noticeably reduces the possible energy conversion and efficiency. Significantly lower and uneven treatment effects are obtained. In order to counteract this disadvantage, two opposite traveling field excitation systems are used and additional measures are taken to make the movement of the working body uneven:

• opposite switching of the excitation fields of the opposing excitation systems over the entire excitation system length (SU-PS 995221, DE-OS 3233926) or in sections (SU-AS 1023573, SU-AS 1103897),
• Change in the distance between the opposing excitation systems over their length (DE-OS 3233926, SU-AS 1103897),
• Field irregularities due to different pole pitches, different feed and dimensioning of the field windings of the opposing field systems (DE-OS 3233926),
• Attaching partitions in the work area transverse to the direction of movement of the field (DE-OS 3233926).

Although each of these measures brings about a reduction in the transport speed, it also results in a significant reduction in the electromechanical energy conversion and thus a deterioration in the efficiency. On the other hand, this entails considerable additional constructive and mechanical engineering expenses as well as increased expenses for operational management, control and process engineering handling.

In rotating field excitation systems there are in principle endless tracks in the plane of the direction of movement of the field for the working bodies, since these excitation systems are self-contained.

In GB-PS 1570934 an outer rotationally symmetrical rotating field excitation system and multiply polarized working bodies are used to additionally irregularize the working body movement.

In the known device for crushing, mixing and stirring with opposing rotationally symmetrical rotary field excitation systems according to DE-OS 3233926, the disadvantage of this device is that the directions of movement of the excitation fields of the outer and inner system are switched in the opposite direction and additional field irregularities due to variable pole divisions, flooding and air gap widths must be realized.

The translatory transport movement, which is constant over time, is required in order to use a stationary electromechanical device that can be used for mechanical processing To guarantee energy turnover in the work area. Therefore - as is known from DD-PS 240674 - for intensive use of the supplied electrical energy and ensuring sufficiently high energy densities in the work space, it is only sensible to form the exciter arrangement on both sides opposite and insecure, to design the working chamber equally unsecured and the excitation winding with regard to its dimensioning, switching and To design the feed so that there is only a single direction of movement of the electromagnetic field penetrating the working chamber. Endless paths, effective energy conversion and corresponding treatment effects are then created for all ferromagnetic components of the work chamber content.

However, the self-locking in the direction of movement of the excitation field is realized by a stringing of a plurality of geometrically finite excitation system parts provided with gap spacing. Such an arrangement is suitable for the dry fine and very fine comminution of granular materials, but not for the mechanical processing of pumpable multiphase mixtures.

The object of the invention is to improve a method of the type described above for processing non-magnetic multiphase mixtures in such a way that the wear of the magnetic working bodies is largely avoided, emissions from the working space are greatly reduced and the yield of microfinished multiphase mixtures is increased with little energy expenditure.

This object is achieved in such a way that a multi-phase mixture flow to be prepared is continuously supplied to the volume at an angle of 90 ° to the rotating electromagnetic field, that by superimposing the axial flow direction impressed by the multi-phase mixture flow and that generated by the rotating electromagnetic field in one Direction in the time-average constant orbital movement of the working bodies, a spiral flow of the multiphase mixture in volume is set so that the working bodies are drawn and held here by the revolving electromagnetic field and its intensity into the volume that the multiphase mixture occupies between the opposing excitation systems and that prepared multiphase mixture is discharged from the volume without the need for additional workpieces.

The further procedural measures result from the features of claims 2 to 7.

Within the scope of the present task, a device for processing multiphase mixtures is also to be created, which has a simple structural design and layout of the electromagnetic excitation systems and the working chamber with an optimal energy yield compared to the energy expenditure for the movement of the working bodies.

This is done in such a way that an annular gap chamber, hermetically sealed except for the inlet and outlet, forms the working chamber and consists of a double tube, the outer tube of which is surrounded on the outside by an outer excitation system and the inner tube of which is surrounded by an inner excitation system on the inside the electromagnetically active area of the working chamber axially into a body-free inlet or. Run-out zone merges, with the working bodies being drawn into and held in the electromagnetically active region of the annular gap chamber along the electromagnetic fields generated by the excitation systems, and in that the annular gap chamber is designed as a unit which is separable from and from the internal and / or external excitation system ( m) can be removed to one side.

The development of the device results from the features of claims 9 to 24.

The advantages of the invention are that an energy adapted to the process can be optimally adjusted and difficult dispersion processes, wetting and mixing conditions can be carried out or maintained.

This enables significant energy savings of more than 50% to be achieved compared to known methods. Due to the extensive hermeticization of the device, pollutant emissions cannot occur. Furthermore, the manufacturing, operating and maintenance costs are minimized by dispensing with any mechanical transmission systems and working body separation devices. With controlled temperature, pressure and working body filling behavior, the device can be integrated into a fully automated process control as an element of the pipeline network.

Fig. 1

einen Längsschnitt A-A einer ersten Ausführungsform einer Vorrichtung nach der Erfindung,

FIG. 2

eine Draufsicht im Schnitt B-B der Vorrichtung nach FIG. 1,

FIG. 3

einen Längsschnitt C-C einer zweiten Ausführungsform der Vorrichtung nach der Erfindung, die gegenüber den FIG. 1 und 2 geringfügig abgewandelt ist,

FIG. 4

eine Draufsicht im Schnitt D-D der Vorrichtung nach FIG. 3,

FIG. 5

einen Längsschnitt E-E einer dritten Ausführungsform der Vorrichtung nach der Erfindung, die sich von den beiden anderen Ausführungsformen geringfügig unterscheidet, und

FIG. 6

eine Draufsicht im Schnitt F-F der Vorrichtung nach FIG. 5.

The invention is explained in more detail below with reference to exemplary embodiments shown in the drawings. Show it:

Fig. 1

2 shows a longitudinal section AA of a first embodiment of a device according to the invention,

FIG. 2nd

a plan view in section BB of the device of FIG. 1,

FIG. 3rd

a longitudinal section CC of a second embodiment of the device according to the invention, which compared to FIG. 1 and 2 is slightly modified,

FIG. 4th

a plan view in section DD of the device of FIG. 3,

FIG. 5

a longitudinal section EE of a third embodiment of the device according to the invention, which differs slightly from the other two embodiments, and

FIG. 6

a plan view in section FF of the device of FIG. 5.

Figures 1 and 2 show sectional views of a first embodiment of the device according to the invention. An annular gap chamber 1 consists of a double tube, the outer tube of which is surrounded by an outer excitation system 4 and the inner tube of which is surrounded or bordered by an inner excitation system 5. “Bordered” is to be understood to mean that the inner excitation system 5 forms the edge of the inner tube. The working space of the annular gap chamber 1 is an annular gap which is chamfered at the bottom 16 and is welded to a curved annular gap disk. The upper end of the annular gap chamber 1 forms a flange 12 which is screwed to a cover 11. An outlet 3 leads through the cover 11 of the annular gap to the outside. The annular gap chamber 1 consists of a non-ferromagnetic material. An inlet 2 for the multi-phase mixture to be processed is arranged at the lowest point of an inclined bottom 16, which likewise consists of a non-ferromagnetic material. In the electromagnetically active working space of the annular gap chamber 1 there are freely movable magnetic working bodies 7 which, within the working space of the annular gap chamber 1, appear to be chaotic, as will be described in more detail below, on endless tracks at a constant speed over time along the path generated by the excitation systems 4, 5 , move in one direction rotating electromagnetic field, the multiphase mixture to be processed flows through the working space, which is fed via the inlet 2 of the annular gap chamber 1 and flows out of the annular gap chamber 1 via the outlet 3.

The two rotationally symmetrical excitation systems 4, 5 consist of laminated cores 4a, 5a, which are formed from individual laminations, and of excitation windings 4b, 5b, which, for example, have three strands and are distributed in grooves in the laminated cores 4a, 5a. The laminated cores 4a, 5a carry these excitation windings, which are equipped with the same number of pole pairs. The excitation windings 4b, 5b are fed by a three-phase network and are interconnected so that there is a rotating and time-changing electromagnetic field 8 which penetrates the annular gap in the radial direction and runs tangentially along the laminated core, ie along the circumference. The field windings 4b, 5b and the laminated cores 4a, 5a of the excitation systems 4, 5 are poured into a solvent-resistant resin 9 and completely surrounded by it, so that there is good heat transfer from the excitation windings to the laminated cores of the respective excitation systems and, moreover, protection of the excitation systems from damaging solvent effects which are possible in the event of an accident given is.

The inner excitation system 5 has an axially continuous cylindrical free space, so that the heat loss generated in the inner excitation system 5 and the heat loss generated in the annular gap chamber 1 can be dissipated, for example, via a central heat sink 6, which the annular gap chamber 1 encloses in such a way that the laminated core 5a of the inner excitation system 5 is in direct contact with the heat sink 6. The heat sink 6 advantageously consists of a non-ferromagnetic tube inserted into the cylindrical free space of the inner excitation system 5 and closed at the top, into the interior of which a cooling tube 10 leads through which a liquid or gaseous coolant flows into the heat sink 6 from below. This coolant flows downward out of the heat sink 6 through an outflow pipe, not specified.

The annular gap chamber 1 is designed as a unit that can be separated from the outer and / or inner excitation system 4, 5 and can be pulled out of the latter upwards or downwards.

The excitation systems 4, 5 lie opposite one another and can be switched on independently of one another. They are designed in such a way that a circumferential electromagnetic field changes over time, in which the already mentioned working bodies 7 made of a hard magnetic material, for example hexaferrite, move. The intensity of the electromagnetic field 8 and its circulation are well adapted to the requirements of the material to be processed. Since the annular gap chamber 1 is largely hermetically sealed, the entire device between the inlet 2 and the outlet 3 is emission-free.

The working bodies 7 have a spherical or barrel-like shape with a diameter or with a length of 1.0 to 4.0 mm. The packing density of the working bodies 7 within the annular gap, i.e. the electromagnetically active working space of the annular gap chamber 1 is in the range from 40 to 90 volume%. In the area of the inlet 2 there is an inflow zone 13 which is free of working bodies 7. In the area of the outlet 3 there is an outflow zone 14, the cross section of which increases in the direction of the outlet 3 and which, like the inflow zone 13, is free of working bodies 7.

The pumpable multiphase mixtures are, for example, dispersions and suspensions, primarily for dye comminution.

• translatorischen Bewegungen in und entgegen der Bewegungsrichtung des Erregerfeldes, d.h. des elektromagnetischen Feldes 8,
• translatorischen Bewegungen quer zur Bewegungsrichtung des Erregerfeldes,
• Dreh- und Taumelbewegungen um die Körperachsen, sowie
• einer überlagerten, im zeitlichen Mittel konstanten Umlaufbewegung in Richtung des Erregerfeldes.

As already mentioned above, the working bodies 7 move macroscopically in the electromagnetic field 8 which is generated by the two excitation systems 4, 5 looks seemingly chaotic on endless tracks. From a microscopic point of view, the paths of the working bodies result from the superposition of:

• translational movements in and against the direction of movement of the excitation field, ie the electromagnetic field 8,
• translational movements transverse to the direction of movement of the excitation field,
• Rotating and tumbling movements around the body axes, as well
• a superimposed, constant movement over time in the direction of the excitation field.

The stream of material to be processed is fed continuously from below at an angle of 90 ° to the circumferential plane of the excitation field and, after flowing through the annular gap, is again removed from the annular gap chamber 1 without an additional collecting device for the working bodies 7. Due to the superimposition of the axial flow direction impressed by the material flow and the orbital movement of the working bodies 7 that is constant over time in one direction on average, the components of the material flow in the working space of the annular gap chamber 1 assume spiral paths. This means that the load path is considerably longer than the axial dimension of the work area.

The flow path can take place both from the bottom up, as in the illustrated first exemplary embodiment of the invention, and via positive guides in the working space or in the annular gap, exclusively from above, as is the case with the second and third exemplary embodiments of the device which are shown in FIGS Figures 3.4 and 5.6 are shown.

The material processing in the annular gap takes place through shear and impact stresses of the components of the material flow with one another, with the working bodies 7 and with the walls of the annular gap chamber 1.

The inlet 2 is a so-called double-angular inlet, i.e. it merges directly into the annular gap without rounding or kinking, while the outlet 3 is designed as a diffuser. In the inflow and outflow zone 13, 14 free of working bodies 7, a homogenization or reduction of the flow velocity of the material flow takes place.

The working bodies 7 are drawn in and held by the electromagnetic field 8 into the electromagnetically active working space of the annular gap chamber 1 during the working process and are used only very slowly as a result of the wear occurring, without physical disturbances occurring in the material flow stream. To comply with limit values, ie to ensure the processing of the machining process, sensors are installed in the area of the material guide and on one of the excitation systems 4, 5.

The temperature is measured at the inlet and outlet 2 or 3 of the material flow and on the excitation windings 4b, 5b in the axial center with the help of temperature sensors 19 and 20, which provide control signals for cooling and for an alarm circuit, not shown, if predetermined limit values Temperature in the material is exceeded. Furthermore, temperature sensors 24, 25 are available for the excitation systems, which either alone or together with the temperature sensors 19, 20 provide the control signals for the cooling and for the alarm circuit as soon as the predetermined temperature limits are exceeded.

For pressure measurement, a pressure sensor 18 is arranged in the annular gap, which actuates a safety contact circuit in order to stop the material flow when inadmissibly high wall pressures are found in the annular gap chamber 1.

The amount of active working bodies 7 in the annular gap can be determined by measuring the voltage on field coils 21 of the external excitation system 4 with the aid of a voltmeter 15.

The field coils 21 are arranged on the tooth ends of the external excitation system 4. With the help of these field coils, the induced voltage is measured and evaluated as a measure of the quantity of the working bodies 7 in the multi-phase mixture by the working bodies 7 moving in the electromagnetically active working space of the annular gap chamber 1.

For material that is difficult to disperse, the arrangement of annular gap chambers connected in series is provided in order to avoid an extreme working length of a single annular gap chamber, which would cause complicated excitation systems and problems during cleaning.

For special preparation processes, the material inlet and outlet in the second and third embodiment of the device, as shown in FIGS. 3 to 6, are only possible from above. In these two exemplary embodiments of the device, the same reference numbers are used for the same components as in the first exemplary embodiment according to FIGS. 1 and 2. In the exemplary embodiments, the excitation systems 4, 5 also consist of laminated cores 4 a, 5 a, each of which carries a three-strand excitation winding 4 b, 5 b distributed in the slots with an equally large number of pole pairs. The inner and outer excitation systems 5 and 4 are also cast in solvent-resistant resins 9, so that they represent closed, ready-to-assemble elements. The inner excitation system 5 is designed as a hollow shaft. The cylindrical free space within the inner excitation system 5 is designed for cooling by means of an air flow or by means of a forced circulation liquid cooling system.

In the second exemplary embodiment, as is shown in the sectional representations of FIGS. 3 and 4, a forced guide projecting from above into the annular gap chamber 1 is installed, which extends to just before the bottom 16 of the annular gap chamber 1. This positive guidance is, for example, a cross-section elliptical or semicircular and against the outer wall of the annular gap chamber 1 or terminating with it, the annular gap tube 22 which connects to the inlet 2. The small axis of the elliptical tube 22 is smaller than the diameter of the inlet 2 and smaller than the width of the annular gap, which is generally in the range from 10 to 40 mm, so that the circulation resulting from the rotating electromagnetic field 8 is constant over time on average the working body 7 is hardly disturbed. The desired flow cross section of the annular gap tube 22 is determined by the large axis of the cross section. FIG. 4 shows both a tube 22 with an elliptical cross section and a tube 22 as a half tube, which terminates with the outer wall of the annular gap chamber. The material flowing in through the inlet 2 is thus guided within the annular gap in the annular gap tube 22 and only emerges into the working space of the annular gap chamber 1 at the bevelled lower end of the annular gap tube 22. The incoming material then presses the multiphase mixture upwards in the direction of the outlet 3 from within the annular gap.

Likewise, a plurality of tubes 22 with an elliptical cross-section projecting into the annular gap chamber 1 and resting on the inside of the outer or inner wall of the annular gap chamber, which tubes are fed via several inlets 2 or through a suitable distributor system in the cover 11 via an inlet 2, can also be used. The annular gap tube 22 is also designed, for example, as a half tube, which then contacts the inside of the outer or inner wall the annular gap chamber 1 connects or is connected to the inside.

The remaining elements of the second embodiment of the device correspond to the corresponding elements of the first embodiment, so that they will not be described again.

In the third embodiment of the device shown in FIGS. 5 and 6, as in the second embodiment of the device, the material is fed in and out from above. In this embodiment, instead of guiding the material through an elliptical annular gap pipe, the material is guided inside the annular gap chamber 1 by means of a cylindrical ring wall 23, which projects into the closed annular gap chamber 1 from close up to the end thereof. This annular wall 23 divides the annular gap chamber into two sections and thus leads to a doubling of the path of the material and thus to a particularly intensive preparation of the material. The ring wall 23 advantageously leads centrally through the annular gap.

It is also possible, although this is not shown in the drawing, to arrange both the inlet and the outlet of the annular gap chamber in the bottom and to provide corresponding positive guides in the annular gap as in the second and third exemplary embodiments of the device.

In general, the annular gap chamber 1 and the working bodies 7 are rinsed by a flushing agent flowing continuously through the annular gap chamber 1. During the flushing process, the excitation systems are either operated with reduced power by means of economy circuits of the excitation windings 4b, 5b or one of the excitation systems is switched off in order to achieve a slowed movement of the working bodies.

It is also possible to operate the processing method discontinuously, that is to say to introduce the multiphase mixture discontinuously into the working space of the annular gap chamber 1 and to remove it from the working space and to separate it from the working bodies after a time-based processing time, for example with the aid of filters or sieves.

Claims (24)

1. A process for reducing, dispersing, wetting and/or mixing pumpable, non-magnetic multiphase mixtures by means of electromagnetic energy, which acts on magnetic working media within substances in a closed volume, the working media moving differently under the influence of an electromagnetic field and the multiphase mixture being surrounded on two sides by two self-contained exciter systems which are opposite each other at a constant distance, generate in each case a changing electromagnetic field which rotates in the same direction and penetrates the multiphase mixture in one direction, and pass tangentially around the volume which the multiphase mixture takes up between the opposite exciter systems, wherein a stream of multiphase mixture to be prepared is fed continuously to the volume at an angle of 90° with respect to the rotating electromagnetic field, wherein a spiral flow of the multiphase mixture is established in the volume by superposing the axial flow direction imparted by the stream of multiphase mixture and the rotational motion of the working media, constant in one direction on average over time, produced by the rotating electromagnetic field, wherein the working media are drawn by the rotating electromagnetic field and its intensity into the volume which the multiphase mixture takes up between the opposite exciter systems and are held here and wherein the prepared multiphase mixture is discharged from the volume free from working media without any additional separating devices.
2. The process as claimed in claim 1, wherein the multiphase mixture is fed to the volume continuously from below and flows vertically upward.
3. The process as claimed in claim 1, wherein the multiphase mixture is restrictively guided continuously from above vertically into the volume and downward in the latter, and wherein the multiphase mixture is deflected at the bottom and discharged vertically upward.
4. The process as claimed in claim 1, wherein the volume is subdivided centrally into two regions which are connected to each other and wherein the multiphase mixture is restrictedly fed to the one region from the top and discharged from the other region at the top.
5. The process as claimed in claims 1 to 4, wherein the inner of the two exciter systems is cooled with air or a liquid for heat removal from the same and from the multiphase mixture.
6. The process as claimed in claims 1 and 2, wherein, before introducing the multiphase mixture, the volume is flushed by a flushing agent passed continuously through and wherein, during the flushing, the exciter systems are operated at reduced power or one of the exciter systems is switched off, in order to achieve a slowed, gentle motion of the working media.
7. The process as claimed in claim 1, wherein, after a predetermined working time, the multiphase mixture is separated from the working media and discharged from the working space.
8. An apparatus for reducing, dispersing, wetting and/or mixing pumpable, non-magnetic multiphase mixtures by means of electromagnetic energy, which acts on magnetic working media within substances in a closed volume, the working media moving differently under the influence of an electromagnetic field and the multiphase mixture being surrounded on two sides by two self-contained exciter systems which are opposite each other at a constant distance, generate in each case a changing electromagnetic field which rotates in the same direction and penetrates the multiphase mixture in one direction, and pass tangentially around the volume which the multiphase mixture takes up between the opposite exciter systems, wherein an annular-gap chamber (1), hermetically sealed apart from the inlet and outlet, forms the working chamber and comprises a double tube, the outer tube of which is surrounded on the outside by an outer exciter system (4) and the inner tube of which is surrounded on the inside by an inner exciter system (5), wherein the electromagnetically active region of the working chamber passes axially over into a working-media-free inlet zone (13) and outlet zone (14), the working media (7) being drawn into the electromagnetically active region of the annular-gap chamber (1) along the electromagnetic fields generated by the exciter systems (4, 5) and held, and wherein the annular-gap chamber (1) is designed as a unit which can be separated from the inner exciter system (5) and/or outer exciter system (4) and can be removed from the latter to one side.
9. The apparatus as claimed in claim 8, wherein the annular-gap chamber (1) consists of non-ferromagnetic materials and encloses a central heat sink (6), into which a cooling tube (10) is introduced, through which a liquid or gaseous coolant flows in.
10. The apparatus as claimed in claim 8, wherein the cross-section of the outflow zone (14) increases in the direction of the outlet (3) and wherein the outflow zone, free from working media, goes over into the concentrically arranged, screen-free outlet (3), which is taken through a cover (11) of the apparatus.
11. The apparatus as claimed in claim 8, wherein the closed inner and outer exciter systems (4 and 5) lie opposite each other at the annular gap of the annular-gap chamber (1), which has a width of 10 to 40 mm, and wherein each of the two rotationally symmetrical exciter systems (4, 5) comprises sheet assemblies (4a, 5a) of individual sheets and exciter windings (4b, 5b), which are fed with three-phase current and are interconnected in such a way that the annular gap is permeated radially by an electromagnetic field (8) changing over time, which passes through in the tangential direction of the sheet assemblies (4a, 5a).
12. The apparatus as claimed in claim 11, wherein the sheet assemblies (4a, 5a) comprise punched sheets and in each case bear the three-phase exciter windings distributed in slots and having the same number of pairs of poles.
13. The apparatus as claimed in claim 11, wherein the sheet assemblies and exciter windings of each of the two exciter systems (4, 5) are cast in solvent-resistant resins (9) or are impregnated with such resins.
14. The apparatus as claimed in claim 8, wherein there are temperature measuring sensors (24, 25) for temperature measurement of the exciter systems as well as temperature measuring sensors (19, 20) for determining the temperature at the inlet (2) and at the outlet (3) of the annular-gap chamber (1).
15. The apparatus as claimed in claim 8, wherein a filling-level measuring sensor (17) and a pressure measuring sensor (18) for determining the multiphase mixture pressure in the annular-gap chamber (1) are arranged in the annular gap.
16. The apparatus as claimed in claim 8, wherein a number of field coils (21) are arranged at the ends of the outer exciter system (4), by means of which coils the induced voltage is measured and evaluated by the working media (7) moving in the electromagnetically active region of the annular-gap chamber (1).
17. The apparatus as claimed in claim 16, wherein the working media (7) are ball-shaped or barrel-shaped bodies of hard-magnetic material, of a diameter of 1.0 to 4.0 mm.
18. The apparatus as claimed in claim 16, wherein the packing density of the working media (7) in the annular-gap chamber (1) is 40 to 90 % by volume of the electromagnetically active working space of the annular-gap chamber (1).
19. The apparatus as claimed in claim 8, wherein the inlet (2) is arranged in the bottom and the outlet (3) of the annular-gap chamber (1) is arranged in the cover (11), and wherein the multiphase mixture flows from bottom to top through the annular-gap chamber (1) without restrictive guidance.
20. The apparatus as claimed in claim 8, wherein both the inlet (2) and the outlet (3) are arranged in the cover (11) of the annular-gap chamber (1), in order respectively to feed in and discharge the multiphase mixture from the top.
21. The apparatus as claimed in claim 8, wherein both the inlet (2) and the outlet (3) are arranged in the bottom of the annular-gap chamber (1).
22. The apparatus as claimed in one or more of claims 19 to 21, wherein there are one or more annular-gap tubes (22) projecting into the annular-gap chamber (1).
23. The apparatus as claimed in claim 22, wherein the annular-gap tubes (22) have an elliptical cross-section and bear against the inner side of the inner or outer wall of the annular-gap chamber (1).
24. The apparatus as claimed in claim 22, wherein the annular-gap tubes (22) are half-tubes which are connected to the inner side of the inner or outer wall of the annular-gap chamber (1).

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