EP0945168B1 - Process and apparatus for the preparation of a homogeneous mixture in continuous way - Google Patents

Abstract

The mixing of difficult-to-mix materials, e.g. water and polyacrylamide suspension, comprises injecting air into both components and providing variable mixing stream profiles in a static mixer. When components are difficult to mix, e.g. water and polyacrylamide suspension, air is injected into both components as they enter a mixing chamber. The gas enters through a nozzle (3) at the top and water is fed into the base. Air connections (6,7) enter the nozzle, and a water bath through an aerator (10). The water passes upward through a floor (11) to be put into rotation by a fixed vane (12). An indirect level sensor (2) and the position of the vane, whose level is variable, automatically control the profile of the rotating water. The gas/air mixture passes through a water-free zone (1) and, when mixed, passes through a perforated floor (13) to an outlet (9). The process can be carried out at elevated pressure or partial vacuum. The capacity of the smallest mixer is about 1 liter and the mixing time is measured in seconds.

Description

The present invention relates to a device for continuous manufacturing and online dosing homogeneous mixtures of difficult to mix gaseous, using liquid or solid mixes a liquid solvent, preferably water, consisting of at least one small dimensioned working under overpressure or underpressure conditions Mixing chamber.

The liquid mixed substances can be emulsions, Act dispersions or the like, solid Mixed substances can be made from powders, granules or the like exist.

Methods and devices are known which are used for continuous Production and dosage more homogeneous Mixtures are used. Here are with restrictions the so-called STATIC MIXERS and the DYNAMIC MIXERS (see trade journal "Chemical plant process" 4/97, page 89), as well as the DE-PS 32 22 209 worth mentioning.

In the aforementioned DE-PS 32 22 209 and in EP 0 096 746 B1 is a continuous manufacturing process of mixtures and inline doses of two heavy miscible components, preferably of water and a polyacrylamide suspension described in which the components via a dosing point of a closed, supplied with a turbine-equipped mixing cell and mixed, which is characterized is that in the mixing cell a gas cushion by feeding is formed by air, which means that the mixed goods initially " be kept contactless "and that the intensive mixing in a pipe mixer connected to the mixing cell he follows.

A device is also described in the cited DE-PS, the only liquid on the mixture Dosing is aligned and to carry out the Procedure serves. The device essentially consists from the fact that by means of an injector the air for the gas cushion is generated and a turbine in the mixing cell is arranged by the pressure difference of the first component is driven, and that the supply line of the second Component arranged at a distance from the surface of the mix is.

With the static mixers, they are because of their small dimensions Design also called tubular reactors, are mixers that are mostly continuous Use, take up little space and compare procured to the dynamic mixers inexpensively can be. Because of the lack of moving Parts include running costs and set-up times low when changing varieties. They are devices with fixed internals using the flow energy effect the mixing of fluid product flows. They become continuous and discontinuous Homogenization and dispersion in all areas chemical process technology.

For this, however, the mixed goods must already be pre-mixed or be merged before going over a Conveying device (pump) for further intensive mixing be fed to the static mixer.

A direct merging and mixing of several Mixing material in the mixer body is not due to the design possible because the static mixer is only from a tube with fixed static mixer inserts. These mixer inserts differ depending on the mixing feed geometric shapes, but they are cannot and cannot be changed during the mixing process thus have no influence on the quality of the solution the mixture. Due to the closed design is also not a visual control of the mixing process possible (trade journal "CHEMIE TECHNIK", 25. Year -1996- No. 1, page 12 + No. 8, page 38).

The dynamic mixers are in contrast to do this, as a rule, discontinuously, i.e. in Batch operation, working mixers, which are very expensive in purchase and require considerably more space. The set-up and cleaning work is accordingly associated with considerable additional effort. System-related moving and rotating parts are required hence an unevenly higher operating cost and Energy consumption than usual with static mixers.

When compared to static mixers dynamic mixers Combine mixed goods in one step and can mix them together at the same time the technical effort required for this is very large. This applies equally if within mixed operation Changes to the device are made can, which have a direct influence on the mixing quality have e.g. those entered in the mixing room Mixing energies are changed by variations of the Agitator speeds, drive powers etc., or by Limitation of the mixing room volume by level restrictions the batch container etc.

Additional dangers with potentially explosive mixes are due to the relatively large and storage volumes are not insignificant. mixes with air or oxygen sensitive properties for mixed processes in the open system not or only limited suitable.

• geringe Investitionen,
• kleine Bauseise, geringer Platzbedarf,
• Einsatz über einen weiten Viskositätsbereich der Mischgüter,
• Energieeintrag in weiten Bereichen den Mischgütern anpaßbar,
• minimales Reaktionsvolumen für gefährliche Mischaufgaben,
• enges Verweilzeitspektrum,
• gute Anpassung an vorhandene Rohrsysteme,
• minimaler Verschleiß,
• hoher Selbstreinigungseffekt,
• keine rotierenden Teile,
• automatischer Betrieb mit visueller Überwachungsmöglichkeit.

The present invention has for its object to provide a device of the type mentioned, with which essential disadvantages of the known mixing systems listed can be eliminated and includes the following features:

• low investment,
• small building iron, small space requirement,
• Use over a wide viscosity range of the mix,
• Energy input can be adapted to the mix in a wide range,
• minimal reaction volume for dangerous mixing tasks,
• narrow range of dwell times,
• good adaptation to existing pipe systems,
• minimal wear,
• high self-cleaning effect,
• no rotating parts,
• automatic operation with visual monitoring.

The task is solved by a Device according to claim 1.

In the device according to the invention, the mix can fed directly to a mixing chamber and visually controllable there be mixed. Corrections or interventions during the mixing process it is possible at any time by adding a static mixer insert and one for the fill level responsible electronic level sensor height adjustable are arranged. The procedure can also both in the pressure and in the vacuum range (vacuum) be performed. The procedure with the Device according to the invention in the vacuum area is used when there is annoying air or Influences of oxygen should be avoided, e.g. at mixed goods sensitive to oxidation. The already for this Known mixing systems used require one considerable additional technical effort than it does with the the method according to the invention is the case.

In the procedure in the overpressure area an additionally installed ventilation unit enables the solvent intensely before entering the mixing zone to ventilate and, if required, the mixing task does that in the subsequent mixing process of the excess portion not taken up by means of a venting device immediately from the same Eliminate mixing chamber.

New mixing tasks can be realized with this procedure and carried out, e.g. also by a Modular summary of several consecutive Mixing chambers in a network.

In a modification of the device according to claim 1 specified a device according to claim 2, which is that in a small dimension Reaction chamber of a mixing chamber, which with a transparent top is equipped, the mixed goods merged in a controlled manner and immediately intensively together are mixed, being at any time of the Mixing process there is an option through stepless Changes e.g. the static mixer position or of the electronic chamber level responsible for the mixing chamber Level sensor in the mixing process effectively intervene. By means of one connected to the mixing chamber Control and operating module, its electronic Circuit operations are not shown here, the Automated mixing process and the current interconnection the mixing device can also be visualized.

Advantageous further developments are in the subclaims the device according to claim 2 described.

In connection with the conveyor, for example a combined suction and pressure pump, the Combine mixing chambers very well, e.g. a Mixing chamber in the suction line under negative pressure conditions and another mixing chamber in simultaneously the pressure line of the same pump under overpressure conditions operate.

Each mixing unit is with a small dimension Control electronics with visual status display Execution of a fully automatic process combined.

Using the drawings, using the example of an overall circuit diagram and a preferred embodiment Device according to the invention will be explained in more detail.

Fig. 1 ein Prinzipschema einer Ausführungsform der Vorrichtung gemäß der Erfindung.

Fig. 2 zeigt ein Schaltschema zum Betrieb der erfindungsgemäßen Vorrichtung im Unterdruckbereich (Vakuum).

Fig. 3 zeigt ein Schaltschema zum Betrieb der erfindungsgemäßen Vorrichtung im Überdruckbereich.

Fig. 4 zeigt ein Schaltschema zum Betrieb der erfindungsgemäßen Vorrichtung in der Kombination der Anordnungen gemäß Fig.2 und Fig.3.

Fig. 5 zeigt eine schematische Darstellung der stufenlosen Verstellmöglichkeiten zur Einflußnahme auf die Mischqualitäten.

In the drawings:

Fig. 1 is a schematic diagram of an embodiment of the device according to the invention.

2 shows a circuit diagram for operating the device according to the invention in the vacuum region (vacuum).

3 shows a circuit diagram for operating the device according to the invention in the overpressure range.

4 shows a circuit diagram for operating the device according to the invention in the combination of the arrangements according to FIGS. 2 and 3.

Fig. 5 shows a schematic representation of the stepless adjustment options to influence the mixing qualities.

As can be seen from the figures, the device is made essentially of two basic parts, the mixing chamber 1 with a small-sized reaction space, in which the mixed goods are brought together and mixed are, as well as one connected to the control line f electronic control and operating module a with which is a continuous and in particular a fully automatic Continuous mixing is guaranteed.

From the device according to FIG. 1 it can be seen that a Dosing lock 3 at the apex of the mixing chamber is attached, on the body of the supply connections for the mix 5, a combined vacuum pressure gauge 4 with safety valve 4/1 and the two supply connections 6, 7 are located, which are independent from each other via the flexible supply lines 6/1 and 7/1 from the respective solenoid valves 6/5 and 7/5 or via the two manual valves 6/4 and 7/4 be charged. At positions 6/2, 7/2 and 6/6, 7/6 are only connection fittings for the respective ventilation supply lines, wherein these are equipped with pressure gauges 6/3 and 7/3 for checking are. The one primarily intended for ventilation tasks Supply line with the integrated solenoid valve 7/5 can also use the check valve 7/7 and the Aeration unit 10 gaseous media directly into the solvent inject what is going on during the ventilation process the supply line with the integrated solenoid valve 6/5 otherwise only indirectly, via the solvent-free zone LZ, is possible.

The arrangement of the two working independently Ventilation systems 6, 7 allow ventilation of the solvent via the solenoid valve 7/5 and the ventilation unit 10, with the ventilation at the same time the mixing chamber 1 via solenoid valve 6/5 into the free atmosphere is possible. These aeration and ventilation processes are fully automated by the control and operating module a controlled.

The solvent is fed into the mixing chamber via the inlet 8 1 introduced, aerated by the ventilation unit 10 and by a static integrated in the bore 11 Mixer insert 12 in highly turbulent rotating ring layers added. The mix is fed from the metering lock 3 coming across the solvent free zone LZ vertically from above into this turbulent solvent flow introduced, mixed and over a distributor floor 13 supplied with slots to the output 9 to the Leave mixing chamber 1 as a homogeneous mixture.

Height is adjustable on the outer wall of the mixing chamber 1 a level sensor 2 is arranged, the contactless through the mixing chamber wall Level of the mixing chamber 1 detected. The solenoid valves 6/5, 7/5 and the electronic level sensor 2 are included the control and operating module a via the control line f electrically connected to each other.

On the surface of the top of the control and operating module a is symbolically the mixing chamber with the respective associated aggregates shown with flashing and / or color-changing LEDs L1, L2 are the current interconnection of the mixing device identifies, in particular the solenoid valves 6/5, 7/5, the electronic level sensor 2 and the function lamp b.

The surface of the housing of the control and operating module a is with an electrical switch d to the friend Vent and e to switch the module on / off.

The control and operating module a is circuit-wise designed that an electrical connection of all shown, given electrically operated units together is. With the use of electronic components thus an automatic and controlled mixing process can be set, whereby the energy supply of the control and control module by means of the plug 10 from conventional 220 V sockets.

In the device according to Figure 2 is the operation of the invention Device in the vacuum area, e.g. in the suction line of a suction and pressure pump 9/1 with downstream valve 9/2 and flow meter / flow monitor 9/3 shown. With this process arrangement the control and operating module a with the Switch d set to the "vent" function.

This ventilation function is only in the vacuum area provided the level in the To keep mixing chamber 1 constant. Should the liquid level rise in the reactor so far that the in a preset position adjusted electronic level sensor 2 is activated, the solenoid valve 6/5 opens interval-like and one finely dosed via the manual valve 6/4 Air volume is via the connection fittings 6/6, 6 and Dosing lock 3 fed to the mixing chamber 1 until the desired level in the reactor set and the solenoid valve 6/5 closes again. As Aeration medium can e.g. atmospheric Outside air are sniffed.

The mixes used for the mixing process are as shown in Figs. 2, 3, 4 by an externally operated Dosing unit 5/1 on the connection fitting 5 and Dosing lock 3 by the level of the Mixing chamber 1 dependent solvent-free zone LZ vertically into that generated by the static mixer part 12 turbulent solvent flow introduced.

The suction and pressure pump 9/1 required for conveying the finished mixture continuously draws the homogeneous mixture produced in accordance with the method from the connection fitting of the outlet 9 of the mixing chamber 1 in order to use the valve 9/2 and the flow meter / flow monitor 9/3) to be transported to the end user. The underpressure that results in this method in the mixing chamber 1) 1 can be set by a pressure reducing valve (not shown) in the supply line of the inlet 8 supplying the solvent.

The control and operating module a is via the control line g with the actuators of the pump 9/1 and the valve 9/2, with the flow meter / flow monitor 9/3 and the Dosing unit 5/1 connected. Circuitry are involved these units interconnected so that deviations in the specified flow rate from Flow meter / flow monitor 9/3 registered and e.g. by switching off the pumps 5/1, 9/1 or closing the Valve 9/2 are corrected. With this measure an uncontrolled mixing process avoided and always one constant solution concentration ensured.

The operation according to the invention is shown in the device according to FIG Device in the overpressure area, e.g. in the pressure line of a suction and pressure pump 8/3 with downstream valve 8/2 and flow meter / flow monitor 8/1 shown. With this process arrangement the control and operating module a with switch d set to the "ventilate" function.

This ventilation function is also in the overpressure range as provided in the vacuum area Fig. 2 exclusively for the level in the mixing chamber 1 constant to keep. The ventilation medium is e.g. compressed air suitable.

The mixes used for the mixing process are as shown in Figs. 2, 3, 4 by an externally operated Dosing unit 5/1 in the same way as in the vacuum area 2 in the solvent flow of the Mixing chamber introduced.

A necessary for the promotion of the solvent Suction and pressure pump 8/3 presses through valve 8/2 and the flow meter / flow monitor 8/1 the solvent through the entrance 8 into the mixing chamber 1 into it, so that, as in the negative pressure area 2 a homogeneous mixture according to the process continuously manufactured and via the exit 9 to the end user can be transported continuously.

Control and operating modules a are via control line g with the actuators of the pump 8/3 and the valve 8/2 with the flow meter / flow monitor 8/1 and the dosing unit 5/1 connected. Circuitry are involved these units are also electrically interconnected as shown in Fig. 2.

When carrying out the mixing process in the overpressure range can be used with the second ventilation line, e.g. Compressed air or another gaseous medium Mixing chamber 1 supplied to aerate the solvent become. Via the connection fitting 7/6, the solenoid valve 7/5 the manual valve 7/4 and the check valve 7/7 the gas then passes into the ventilation unit 10 to be finely divided with the solvent before the actual mixing process in the subsequent reaction space takes place. With this advantageous arrangement, for example Be influenced on one more or less rapid mass transfer, maturation process etc.

In gas-liquid reactions, the course of the reaction is determined by the speed of mass transfer. Since due to the device according to the invention the very small dimensioned reaction volume of the Mixing chamber short mixing times (seconds up to Can be realized in fractions of a second) The methods described here also in particular for gas-liquid reactions.

Excess gas that is not absorbed by the solvent can be removed from the mixture can be from the first ventilation line via the connection fitting 6 and the manual valve 6/4 or Solenoid valve 6/5 according to the description Fig. 1 removed become. With this process arrangement, the control and Control module a) with the switch d on the function "vent" set.

The mixture can also be made after leaving the exit 9 again partly the circuit of the pump 8/3 are fed. This will mix the mixture in several times the pump 8/3 circulated. This will make the mix improved.

4 shows the operation of the device with the mixing chamber 1 in the underpressure range, according to the description in FIG. 2 and simultaneously with the mixing chamber (1 ") in the overpressure range, according to the description in FIG. 3, each mixing chamber as an independent one Mixing module can be operated.

• in nur einem Arbeitsgang können zwei unterschiedliche Mischgüter miteinander vermischt werden,
• die für den Transport von Mischungen benötigte Förderpumpe 9/1 kann optimal ausgenutzt bzw. als zusätzliche Mischvorrichtung mitbenutzt werden,
• es können besonders schwer mischbare Mischgüter in zwei unterschiedlichen Druckbereichen (Unterdruckund Überdruckbereich) miteinander vermischt werden,
• physikalisch unterschiedliche Mischgüter können in einem Arbeitsgang miteinander vermischt werden, z.B. in der Mischkammer 1 ein festes Mischgut und in der Mischkammer 1" ein flüssiges Mischgut, oder umgekehrt.

This method in the device shown has e.g. B. The following advantages:

• two different mixes can be mixed with each other in just one operation,
• the feed pump 9/1 required for the transport of mixtures can be optimally used or used as an additional mixing device,
• Mixing materials that are particularly difficult to mix can be mixed together in two different pressure ranges (negative pressure and positive pressure range),
• Physically different mixes can be mixed together in one operation, for example a solid mix in the mixing chamber 1 and a liquid mix in the mixing chamber 1 ", or vice versa.

In the device according to Figure 5, the stepless adjustment possibilities shown, with its Help influence at any point in the mixing process the mixing quality can be taken. This is particularly beneficial if during adjust the mixing process changes, for example the throughput quantities, temperatures, viscosities, Relate to surface activities or the like can.

The representation "mixer lowered" should symbolically show that the static mixer insert 12 in the bore 11 is arranged adjustable in height.

When using different mixer shapes, the Mixer flowing around solvent flow variable Generate mixed geometries and thus according to the Mixer position different mixing energies and Mixing effects in the reaction chamber of the mixing chamber 1 contribute.

• die Einmisch- und Benetzungsfähigheiten der Mischgüter lassen sich individuell beeinflußen,
• die berührungslos arbeitende Niveauerfassung ist verschleißfrei und unempfindlich gegen Verschmutzungen aller Art. Reaktionen zwischen Mischgut und Sensor 2, wie sie z.B. bei Direktkontakten auftreten können, sind ausgeschlossen.
• das einmal mit dem Füllstandsensor fixierte Füllstandniveau bleibt im Sinne eines konstanten Mischergebnisses solange erhalten, bis eine neue Einstellung erfolgt. In Verbindung mit dem Regel- und Bedienmodul a und dem eingangs beschriebenen Be- und Entlüftungssystem wird dieser Vorgang vollautomatisch durchgeführt.

The representation "level sensor lowered" is intended to symbolically show that the electronic level sensor 2 is arranged on the outer wall of the mixing chamber 1 in a height-adjustable manner, the level in the mixing chamber being detected without contact and without contact with the medium. With the respective positioning of the sensor 2, the filling volume is accordingly predetermined, so that the following advantages can be achieved with this arrangement:

• the mixing and wetting capabilities of the mix can be individually influenced,
• The non-contact level detection is wear-free and insensitive to all types of contamination. Reactions between the mix and sensor 2, such as can occur with direct contacts, are excluded.
• The level level, once fixed with the level sensor, remains in the sense of a constant mixing result until a new setting is made. In connection with the control and operating module a and the ventilation system described above, this process is carried out fully automatically.

Claims (10)

1. Device for the continuous production and on-line metering of homogeneous mixtures of difficult-to-mix gaseous, liquid or solid materials to be mixed by using a liquid solvent, preferably water, consisting of at least one mixing chamber with small dimensions operating under excess pressure or vacuum conditions, characterised in that a static mixer insert (12) is arranged height adjustably inside the mixing chamber (1) in a hole (11) providing the inlet on the base, and an electronic level sensor (2) is height adjustably arranged outside of the mixing chamber (1).
2. Device according to claim 1, characterised by at least one mixing chamber (1) with small dimensions equipped with a height adjustable, static mixer component (12), a distribution base (13), an aerator (10) and a height adjustable, electronic level sensor (2) which is connected by the control cable (f) to an electronic control and operating module (8), a metering sluice (3) being placed on the transparent upper part of the mixing chamber (1), on which sluice (3) a combined vacuum-pressure manometer (4) with safety valve (4/1), and the connection fitting (5) for the material to be mixed, the connection fitting (6) for the first aeration and/or venting branch, consisting of the flexible supply line (6/1), the connection fitting (6/2) with manometer (6/3), the metering valve (6/4), the magnetic valve (6/5) and the connection fitting (6/6), are located, the second aeration and/or venting branch consisting of the connection fitting (7) with the flexible supply line (7/1), the connection fitting (7/2) with manometer (7/3), the metering valve (7/4), the magnetic valve (7/5), the connection fitting (7/6) and the return valve (7/7) for the connection to the aeration unit (10), which unit (10) is located in the lower part of the mixing chamber (1) to introduce the aerating medium in countercurrent into the solvent introduced from the entrance (8), so in operation the solvent enriched with the aerating medium subsequently passes through the static mixer insert (12) via the hole (11) and after mixing with the material to be mixed entering vertically from the metering sluice (3) via a solvent-free zone (LZ) leaves the mixing chamber (1) as an homogeneous solution via the distribution base (13) with punched-in slotted grooves and the exit (9).
3. Device according to claim 2, characterised in that the upper part of the mixing chamber (1) consists of transparent and impact-resistant material and in its smallest embodiment the mixing chamber is limited to about one litre total volume.
4. Device according to claim 2 and 3, characterised in that the guide console for receiving the sensor (2) is rigidly connected to the outer wall of the mixing chamber (1), the sensor (2) being provided with a base plate on which a light-emitting diode for illuminating the mixing chamber (1) is located, the electronic level sensor (2) being electrically connected to the control and operating module (a) via the control line (f).
5. Mixing chamber according to any one or more of the preceding claims, characterised in that the static mixer insert (12) is arranged height adjustably in a hole (11) in the centre of the lower side of the mixing chamber (1).
6. Device according to any one or more of the preceding claims, characterised in that the control and operating module (a) is also electrically connected to external units, such as for example the material metering device (5/1), the suction and pressure pump (9/1), the valves (9/2) or the flow control instrument (9/3) and the suction and pressure pump (8/3), the valve (8/2), the flow meter/flow control instrument (8/1) via the control line (g).
7. Device according to any one or more the preceding claims, characterised in that the control and operating module (a) symbolically represent the mixing chamber with the respective associated units which are provided with flashing and/or colour changing light-emitting diodes (L1, L2) which make the current connection of the mixing device recognisable, in particular of the magnetic valves (6/5, 7/5), the electronic level sensor (2), the operating light (b) and the material metering device (5/1) and/or the valves (8/2, 9/2), and a respective electric switch (d) for aerating and venting and (e) for switching on and switching off the module is arranged on said surface of the housing.
8. Device according to any one or more of the preceding claims, characterised in that the control and operating module is designed in terms of circuitry in such a way that an electric connection with one another of all illustrated electrically operated units is provided and therefore a continuous, automatic mixing process can be adjusted by using electronic components, the energy being supplied to the control and operating module by means of the connector (c) from conventional 220 V sockets.
9. Device according to any one or more of the preceding claims, characterised in that the mixing chamber (1) operating under vacuum conditions (vacuum) is provided with a valve (9/2) connected downstream in the suction line of a suction and pressure pump (9/1) and a flow meter/flow control instrument (9/3), a second mixing chamber (1'') optionally subsequently being operated under excess pressure conditions in the pressure line of the same suction and pressure pump (9/1), with valve (9/2) connected downstream and flow meter/flow control instrument (9/3).
10. Device according to any one or more of the preceding claims 1 to 8, characterised in that the mixing chamber (1) operated under excess pressure is provided with a pressure line, a pressure and suction pump (8/3) with valve (8/2) connected downstream and a flow meter/flow control instrument (8/1).

Images