EP1384502A1 - Mixer, heat exchanger - Google Patents

Abstract

The combined static mixer and heat exchanger has a housing (6) with heat exchange pipes (1) with projecting blades (2a,2b) at their circumference, which act as static mixers in at least two parallel levels. The blades are offset from each other by an angle (alpha) of 45-135 degrees and especially 70-110 degrees around the pipe axes. The blades are pitched an angle (beta) to the material flow direction of +/-10 degrees to +/-80 degrees.

Description

The invention relates to a combination of static mixer and heat exchanger for process engineering treatment of thermally sensitive viscous Media consisting of several in parallel next to, on top of each other or offset from one another arranged pipes, which are at an angle, preferably of 90 °, to Product flow direction stand in a housing and the flow is flowing. The Tubes have radially arranged webs on the outer diameter or curved, which are arranged axially offset to the tube axis and on the Pipe axis are offset from each other. The raised contours are arranged that especially in the case of viscous and highly viscous substances and mixtures good mixing effect occurs and at the same time due to the significantly enlarged pipe outer surface rapid, gentle temperature control is only possible.

The quick, even and gentle tempering of viscous and highly viscous Products, e.g. Polymer melting takes place only insufficiently with the known ones static mixer systems described below. As a direct heating surface for such Only the outer temperature-controlled housing or pipe wall is available for tasks Available. For the temperature control of a product, this is repeated several times by the known static mixer from the housing or pipe center to the temperature-controlled housing wall passed so that the desired length with increasing length of the heating section Product temperature is reached. Such temperature control tasks require due to Low thermal conductivity of most organic substances tempered for a long time Mixing sections that lead to a long dwell time and high pressure loss and thereby viscous substances (> 1 mPa.s) with laminar flow velocity, in particular those with a temperature-sensitive character. An additional one The disadvantage of the long mixing sections is the high design-related investment costs of such systems. Disadvantages, such as the low mechanical stability and high Pressure losses of known static mixers lead to large flow cross sections, which in turn make temperature control more difficult.

A slight improvement in temperature control tasks is achieved if known Static mixer pressed or rolled into pipes or into housings become. This will result in limited metallic contact between the heated inner housing wall and the small outer cross-sectional areas of the metallic Static mixer formed. However, the static mixer can be pulled in or rolled in only form an insufficient contact surface with the temperature-controlled housing wall. The Experience shows that contact surfaces are not fully developed, so always Column to the inner housing wall arise. Because of this narrow gap, due to higher thermal conductivity properties of the metallic mixing bars, heat directed radially into the flow area of the static mixer. This method enables only a slight improvement with very small housing or pipe diameters, since the heat conduction to the center of the static mixer or the housing is limited by the small, not fully formed contact areas. Furthermore, these columns are "dead spots", which are used for speck formation, e.g. in polymer melts contribute. The specks (impurities) reduce the quality of the sales products (e.g. thermoplastics).

Known static mixers, which are in somewhat better temperature control properties Housing or pipes are soldered. Soldering requires a precisely prepared one Housing or tube and a machined on its outer diameter Static mixer, so that a good and complete solder connection is achieved can. The mechanical preparations for the parts to be soldered are complex and expensive. Soldered static mixers show a good contact surface when soldered well to the inner tempered housing wall. Because of the geometric structure however, the static mixer is the contact surface to the heated housing surface small, so that only a slightly higher temperature control output to the product flow is possible. The enlargement of the tempered area compared to the rolled area Static mixers are not significantly higher, so mixing sticks with soldered Static mixers, can not be shortened significantly. The soldering process is because of the limited size of the soldering furnace and because of the distortion of the tubes when Soldering only possible with a small tube length (generally <2 m).

Due to the solder used, additional corrosion problems often occur which must be taken into account when using such mixers so that, for. B. Purity and quality of a product due to contamination due to corrosion is not deteriorating.

For the heat transfer of liquid and gaseous substances are still Pipes with outer drawn on or pressed in or welded on known thin sheet metal. Have the outer thin disks no full contact with the actual carrier tube, so they're ready for use for temperature control of air in the highly turbulent flow area preferably be used. These versions are not pressure stable and have none mixing properties for viscous substances in the laminar flow range. Therefore are such pipe systems for tempering more viscous and highly viscous Liquids not suitable. To improve the heat transfer properties e.g. these outer disks and the carrier tube with a low temperature solder completely covered to enlarge areas in contact with the product and thus increasing the heat conduction. The solders used (e.g. zinc, tin) are in chemical processes with high corrosion requirements cannot be used, des furthermore, the mechanical strength of such solders, in particular when subjected to high temperatures, very low.

The temperature-controlled static mixer reactor (DE 2 839 564 A1) is also known. This reactor mixes the product flowing through, the mixing internals consist of meandering tubes. This device exists from a temperature-controlled housing in which the mixing internals by a special shaped meander - tube bundles are replaced.

The pipeline bundle consists of several curved bends running in parallel thin tubes. The ends of the tubes are welded to a flange from which from which the heating or cooling medium for temperature control of the product stream is fed.

The parallel, curved pipes are temperature-controlled internals inserted into the housing parallel to the direction of flow of the product. The meandering pipes are at an alternating angle in the Product flow direction and run across the hydraulic diameter of the housing. The parallel tubes in the bundle cross each other in the axial direction of the housing, according to the known principle of the static mixer. The mixing pipes show a round to in this construction elliptical flow cross-section, the pipes are under a product flow Angle inclined so that only a small distributing deflection or mixing of the product flow to be tempered. There flow round profiles one have a low mixing effect, is a homogeneous temperature distribution in a highly viscous Short flow of product is not sufficient.

The length of the insertable meander tube bundle is always a multiple of the hydraulic housing diameter. The meandering tubes have a large heat transfer surface due to their elongated length. The liquid heat carrier is supplied and removed through the connecting flange, which releases its energy through the tube bundle around which the product flows. In particular when tempering viscous fabrics, the heat insulating properties own, the large heating surface cannot be used effectively because the internals do not have a good mixing effect.

The bent, insertable tube bundles are susceptible to large pressure gradients. When starting up or when the product is blocked due to high viscosity Products experience high pressure gradients, so that the meandering curve Heating / cooling pipes in the product flow direction are subjected to tensile or pressure loads and stretched become. The internal heat-transmitting internals of the apparatus tend to do so for deformation and a further tempering of the product by the then missing redirection of the product is no longer possible. The unwanted stretching of the tube bundle is irreparable and can lead to plant downtime with high failure costs to lead.

The temperature-controlled meandering tube bundle shows due to the ideally stretched Length of the single pipe and the small flow cross-section a high pressure loss and a long dwell time on the tempering side. Both pressure loss and Dwell time e.g. of the temperature control medium in the meander lines leads to high Differences between inlet and outlet temperatures and reduces those for heat transfer important mean temperature difference is crucial. Because of that the performance of such meandering tube bundles is low. In practice several tube bundles are often connected in series, which in turn increases the investment costs, the pressure loss, the dwell time of the temperature to be controlled Fabric and increases the assembly effort.

A uniform and gentle tempering of highly viscous, single-phase or multiphase product streams with a short dwell time can be used with the known systems, e.g. Static mixers with heated housings or temperature-controlled meandering tube bundles do not take place.

This results in the need to develop a temperature-controlled static mixer the heating channels in the product flow and has good mixing properties. The New temperature-controlled static mixers are said to have a low pressure drop on the Have heat transfer side, so that with large temperature differences to the temperature Product flow can be expected. Furthermore, the new apparatus concept be applicable to large hydraulic housing diameters. additional Improvement in terms of high robustness against mechanical influences, against high pressure gradients and the possibility of various heat-conducting and use corrosion-resistant materials to meet different product requirements would be beneficial.

Further requirements exist with regard to a good adaptation to different ones procedural tasks with regard to low pressure loss on the product-touched and the tempered side, high mixing performance, one short residence time spectrum on the product side, large temperature control area and high heat transfer performance. The invention is intended for the use of viscous to highly viscous substances (viscosity 0.001 to 20,000 Pa.s) significant advantages demonstrate.

The mechanical stability during start-up processes or during assembly should be increased, so that higher operational reliability is also achieved.

The new device is said to be a compact heat exchanger with a low Installation wall and low manufacturing costs installed in production facilities can be.

In summary, the object of the invention is a static mixer / heat exchanger provide the disadvantages of the known constructions of the prior art technology avoids a significantly improved temperature control with less Apparatus volume enables, reduces the manufacturing costs of the apparatus and greater robustness, operational reliability and service life than known heat exchangers having.

The object is achieved according to the invention by a mixer / heat exchanger according to the preamble of claim 1 with the characterizing features of Claim 1.

The invention relates to a static mixer / heat exchanger for the Treatment of viscous and highly viscous products, at least comprehensively an optionally temperature-controlled housing for the passage of the product in which in particular at least two at right angles to the main flow direction of the product, preferably tempered tubes arranged one behind the other, in particular temperable are arranged by passing a heat transfer medium, whereby on attached to the circumference of the pipes a variety of heat exchanger webs are characterized in that the heat exchanger webs along each Tube are aligned in at least two parallel layers and the webs of the different positions at an angle α of 45 ° to 135 °, preferably from 70 ° to 100 °, particularly preferably from 85 ° to 95 ° to one another about the axis of the tube are arranged twisted and that the webs of the different layers to the main flow direction of the product through the housing at an angle β of ± 10 ° stand up to ± 80 °.

The webs of the different layers are available in a preferred embodiment Main flow direction of the product through the housing at an angle β from ± 30 ° to ± 60 ° and particularly preferably at an angle β of ± 40 ° to ± 50 °.

A mixer / heat exchanger is preferred, characterized in that each web of a layer has a web opposite this web on the tube is arranged. In the simplest case, both webs are then exactly on the tube at an angle of 180 ° opposite.

A mixer / heat exchanger is also preferred, characterized in that the Bars of the different layers of bars alternating over the length of the tube are arranged. This further improves the mixing effect.

In a preferred embodiment, the webs are designed such that the webs of the various web layers along the tubes to each other on a gap are.

For processing higher viscous products, in an alternative design Mixer / heat exchanger, the distances between the webs of the different layers along of the pipe to each other to gap to reduce the pressure loss.

For processing higher viscous products, in an alternative design Mixer / heat exchanger, the distances between the webs of the different layers along of the pipe so chosen that the gap between the pipe-axial neighboring Webs is larger than the respective web width.

The gaps enlarge the product flow cross section and reduce it Pressure loss. If the gaps are smaller than the respective axial web width, this increases the pressure loss and at the same time the heat transfer surface of the pipes.

In a special embodiment, the web width / gap ratio is between two webs two adjacent web layers less than 1, preferably less than 0.7 and particularly preferably less than 0.5 in order to reduce the pressure loss.

A mixer / heat exchanger is also preferred, characterized in that that several tubes with webs in the housing transverse to the main flow direction are attached side by side.

Under the main flow direction of the product, the direction becomes parallel to Denoted longitudinal expansion of the housing, which follows the product flow, in tubular Housing the direction parallel to the central axis of the housing.

In a preferred form of the mixer / heat exchanger, the tubes have Temperature control channels for the passage of a liquid heat transfer medium, in which Outflow area of each channel a nozzle with a smaller than the channel hydraulic diameter, to limit the flow rate of the temperature control medium, is appropriate.

The diameter of the nozzle is preferably only half as large as the hydraulic one Channel diameter of the respective pipe.

The preferred integrated nozzle at the end of the temperature control channel, in the outflow area of the pipes, reduces the flow rate of the liquid temperature control medium when completely flooded channel. This increases the even flow many parallel tubes of the mixer / heat exchanger.

In a particularly preferred form of the mixer / heat exchanger, this Housing of the mixer / heat exchanger one separate supply and one separate dissipative housing area for the heat transfer medium to the To supply inflow and outflow areas of the temperature control channels. This is done forced flow through the web tubes.

The temperature-controlled mixer / heat exchanger can be a circular (hydraulic) or show a rectangular cross-section so that the cross-sectional shape of the module can be adapted to the procedural need. The Mixer has a height from length to diameter L / D <10, preferably at larger diameters the L / D ratio is <5 and this is particularly preferred L / D ratio <1.

A preferred variant of the mixer / heat exchanger is characterized in that that in the housing in several levels one behind the other (in the main flow direction) tubes provided with webs, in particular with different web shapes pipes or versions provided are attached. This multi-stage On the one hand, execution enables the mixed material to be mixed more locally on the other hand, due to the different heating surface in the Product flow direction, a temperature gradient along the pipes Mixing section enables.

By choosing the distances "a" (see Fig. 13) of the horizontal tubes can the outer webs form gaps defined to each other. By varying the vertical Pipe distances "h" can form gaps between the individual mixing levels, so that there is a reduction in pressure loss and a good welding connection of the mixing elements formed in segments with the housing is.

A preferred one is to intensify the mixing effect and tempering further Mixer / heat exchanger constructed so that the radial expansion of the arranged adjacent tubes, each adjacent heat exchanger webs overlaps.

The variation of the pipe distances across the product flow direction or the variation of the distances in the product flow direction enables an improvement of the Mixing and temperature control processes with simultaneously lower apparatus volume (hold-up). When flowing through the mixer / heat exchanger takes place in a close arrangement an interlocking of the temperature control bars, side by side or one behind the other arranged pipes. That increases the flow rate and in Follow the tempering and mixing performance.

A mixer / heat exchanger is also preferred, characterized in that that the radial extension of the webs is at least 0.5 times to 30 times, preferably at least 5 times to 15 times the inner diameter of the connected pipe is.

A mixer / heat exchanger is also preferred, characterized in that that the radial webs on the tubes are hollow and the web cavity is a direct one Has connection to the pipe interior.

In special versions, the guide surfaces of the webs are raised, so that the heat-exchanging area is increased further and additional mixing or flow effects especially when passing through low-viscosity substances occur.

The radial expansion of the webs and the resulting effective heat exchange area while reducing the local pressure drop at the same time due to the thermal conductivity properties of the pipe material used and the substance-specific heat transfer coefficient of the product to be tempered cannot be chosen arbitrarily large. A large radial expansion of the webs can take place when the webs are hollow and the web cavity is a direct one Has connection to the channel of the pipe. Is a high dispersion performance on the process side If required, the radial expansion of the webs can be chosen to be large, so that intersect the webs in different levels or webs of neighboring pipes mesh. The tubes with hollow webs can be cast in one piece getting produced. Due to modern welding processes (laser welding) even a welded construction is economical.

A variant of the mixer / heat exchanger is also preferred characterized in that the inner wall of the pipes is contoured for enlargement has its surface, in particular in the form of longitudinal ribs. In analogy to The interior of the temperature control tube is preferably the outer surfaces of the temperature control tubes and in particular contour the webs to the product side Enlarge heat transfer area.

Alternatively, the mixer / heat exchanger is preferably designed so that the pipes are provided with an electrical resistance heater.

The mixer / heat exchanger comes as a heater with the pipes inserted electric heating cartridges are used, the separately designed supply lines are not required and dissipative lines for temperature control, so that the pipes with the enclosing housing are directly connected, one-sided with the heating cartridges can be equipped.

When using liquid tempering agents, the temperature range of the Mixer / heat exchanger from -50 ° C to + 300 ° C. Above 300 ° C the Mixer / heat exchanger operated with electric heating cartridges up to 500 ° C become.

Another preferred design for the implementation of catalyzed processes is the Mixer / heat exchanger is advantageous, which is characterized in that the Pipes and / or the webs on their surface in contact with the mix with a catalyst are coated.

The web tubes of the mixer / heat exchanger are preferably formed in one piece, e.g. in that the pipes with webs in the casting process or as a forging are made.

The production of the tubes with webs or the web tubes by casting or forming technology has cost advantages. In particular, the homogeneous material structure good heat conduction from the flowing tempering agent to the product contact External surface secured and cold bridges avoided. For this reason, in particular metallic, alloyed CrNi materials, Cu connections, aluminum, titanium, Highly alloyed nickel steels or precious metals are preferred as materials.

The mixing effect and heat exchanger function are particularly effective in one preferred mixer / heat exchanger, in which the web tubes in the transverse direction to Main flow direction of the product at an angle γ of at most +/- 15 Degrees are arranged in the housing.

For special mixing tasks, a preferred mixer / heat exchanger is advantageous, in which one behind the other in the housing in several levels in the flow direction webs are attached, and the tubes of the levels differently dimensioned webs compared to the webs of the pipes of neighboring Have levels.

A mixer / heat exchanger is preferred, characterized in that at least two parallel groups of tubes with webs arranged one behind the other have different web shapes.

A mixer / heat exchanger is particularly preferably constructed, characterized in that that at least one tube with webs in one plane with one Pipe extension through the supply or discharge temperature range is guided outside the housing and the channel of the bridge tube on one side is closed and at least two radial openings connect the channel of the bridge tube to the flowed through product space of the mixer / heat exchanger forms an additional liquid or gaseous component in the main stream to direct the mix and mix it immediately.

The direct injection of an additional substance via an extended one Stegrohr, enables the use of the mixer / heat exchanger as a reactor. On the one hand, a dye or an additive or an entrainer can be added are e.g. dyeing viscous products, realizing admixtures or Add detergent for a subsequent cleaning step. Another procedural use becomes possible if e.g. a reaction component over the flow cross section of the mixer / heat exchanger in the Main flow metered in and thereby initiated or started a chemical reaction becomes. Any heat of reaction that arises from the start of an exothermic Reaction, can be removed immediately to keep the process isothermal.

Another preferred embodiment of the invention with plug-in temperature control units is possible if the housing of the product-side flow channel in Flow direction has lateral openings through which the temperature control unit transversely to Flow direction can be used, so that the product-side flow cross-section is completely filled with the temperature-controlled static mixer unit. Several plug-in temperature control units can then, each in the main flow direction offset by 90 degrees, inserted into the product-carrying channel of the housing become. This disassembles and assembles the device for cleaning purposes due to e.g. of a product change considerably simplified. The one-sided In this version, adjustable temperature control units are equipped with heating medium on one side supplied, so that via an extended capillary extending into the temperature control channel the tempering leveled the flow conditions of the heat exchanger and another. No narrowing of the temperature control channel.

In special versions of the mixer / heat exchanger, pipes are also used outer webs or baffles arranged one above the other in a U-shaped housing and welded both U-shaped housing shells to a tight housing, see above that there is a right-angled flow cross-section for the product to be tempered forms (Figure 2, 2a).

Another user-friendly version of the mixer / heat exchanger consists of, if temperature-regulating tube ends each in separate heating pockets, for the supply and discharge of the temperature control medium, used, welded and be provided with a flange on one side in order to be plugged in as temperature control units an adapted housing to be used.

The stacked tubes with the one-sided distribution pockets can be pushed into temperature-controlled housings as plug-in units. In such a Arrangement is particularly small heating area in a small space, so that product-friendly temperature control takes place with a short dwell time. A special The advantage for the user is the possibility of cleaning the temperature-controlled ones Mixer unit.

A plurality of mixers / heat exchangers can preferably be arranged one behind the other are, optionally in combination with known static mixers. The Mixer / heat exchanger can be set at an angle δ of 45 to 135 °, e.g. of 90 °, rotated relative to one another about the central axis of the housing.

By connecting several mixer / heat exchangers in series a chemical reaction in a static-mixing reactor is sufficiently homogenized and kept isothermal.

The mixer / heat exchanger is a powerful temperature control unit that itself a high heat transfer capacity at laminar flow rate allows. For this reason, the mixer / heat exchanger according to the invention preferred for the construction of low backmixing flow reactors, suitable for carrying out exothermic and endothermic processes. ever According to the task, process-intensive reactor areas in which a Reaction is started, rapid heat exchange is desired and according to dwell time ranges which are less temperature regulating and only mix is differentiated. Dwell time ranges of flow reactors can e.g. Tempered tubes with known static mixers used.

The main application of the invention is in the field of gentle quick Temperature control of viscous to highly viscous material systems. In these applications in addition to an effective temperature control is always a good and effective mixing required to maintain a constant temperature across the flow cross-section to achieve.

The possibility of adding another substance via the additional preferred substance feed To feed and distribute directly into the main stream, additives or Dyes are mixed in so that in a process plant additional mixing sections can be omitted. Especially in processes for demonomerization of polymer melts can be entrained directly into the Melt can be metered in, at the same time takes place through the effective temperature control a gentle short-term heating of the polymer to a higher temperature level, without initiating thermal product damage, so that a downstream Evaporation step as a cleaning step, e.g. an easier boiling unwanted component can be performed.

Several consecutive mixers / heat exchangers can be used for this are used to design low-back-mixing tubular reactors. For example, a Reaction component via the additional feed of a preferred Mixer / heat exchanger evenly in the reaction space (product space) be distributed. In the case of endothermic reactions, the Reaction required energy can be supplied immediately. Arises during the Reaction heat, so can the heat of reaction when connecting a refrigerant be discharged immediately.

With the invention mentioned, small, compact high-performance heat exchangers can be Form for low-viscosity and high-viscosity, liquid and gaseous substances. The devices show a very stable design, can because of the stable Execution used with high pressure gradients have a large heat transfer Area and work with low backmixing. Especially in applications for tempering viscous and highly viscous single-phase or multi-phase The advantages of material systems are particularly noticeable due to their short residence times.

The flow behavior of very highly viscous material systems implies a lot high pressure loss, which is why only low flow velocities are economical possible are. The specialist speaks of creeping currents. Here is the Heat exchange between the heat transfer medium and the product is particularly bad. With these In addition to the large heat-exchanging surface, application is simultaneous intensive mixing process necessary for gentle and uniform heating of the product. The temperature of the product is adjusted accordingly Arrangement of the web tubes with a very short dwell time and a small dwell time spectrum, so that in particular temperature-sensitive substances with the invention Mixer / heat exchanger can be tempered.

In individual cases, the invention can even be used at a fully tempered temperature Housing are dispensed with, which u. a. Investment costs can be further reduced.

Due to the high conceptual flexibility of the mixer / heat exchanger according to the invention, by combining the pipe distances "a" and "h" with different Web areas, variation of the number of web tubes next to each other, with each other or offset with each other, as well as the variation of the pipe spacing across or with the main flow direction of the product, there is possibility for everyone to meet procedural and product-specific requirements.

The device always works with small temperature differences between input and Escaping the heat transfer medium or the coolant, so that a high power transfer when tempering and a very good use of the secondary energies is possible.

The invention enables compact, pressure-resistant and inexpensive heat transfer apparatus or low backmixing tubular reactors. The form of insertable Mixer / heat exchanger units in appropriate tempered housing results particularly user-friendly apparatus that allow easy cleaning.

In particular, the application as a low back-mixing tubular reactor with a integrated unit for uniform feeding of a reaction component via offers the hydraulic flow cross-section of a primary main product stream Further technical applications that were previously available with state-of-the-art units technology are not possible.

The invention is explained below with reference to the figures by the examples which but do not constitute a limitation of the invention, explained in more detail.

Figur 1

einen Längsschnitt durch das Gehäuse 6 eines erfindungsgemäßen Mischer/Wärmeaustauschers gemäß Linie A-A in Figur 1a und den Winkelversatz der Stege zu einander sowie die Winkelannordnung der Stege zur Hauptströmungsrichtung.

Figur 1a

Teil-Querschnitt und seitliche Ansicht des Rohres 1 mit Stegen 2a und 2b nach Figur1.

Figur 2

zeigt einen Mischer/Wärmeaustauscher mit zwei parallel angeordneten Rohren 1 in einer Ebene mit Stegen 2a und 2a' im Bereich der Produktströmung, sowie den Winkelbereich α der Stege 2a und 2b und den Winkelbereich β der Stege zur Hauptströmungsrichtung.

Figur 2a

zeigt den Mischer/Wärmeaustauscher gemäss der Linie B-B aus Figur 2 mit einer zuführenden Wärmeträgerkammer 4 und einer abführenden Wärmeträgerkammer 5 und den Winkelbereich γ für die Schrägstellung der Stegrohre im Bereich der Produktströmung.

Figur 3, 3a

eine Variante zu einem Stegpaar 2a aus Figur 1 im Querschnitt.

Figur 4, 4a

eine weitere Variante zu einem Stegpaar 2a aus Figur 1.

Figur 5, 5a

eine weitere Variante zu einem strömungsoptimierten Stegpaar 2a aus Figur 1.

Figur 6, 6a

eine Variante zu einem Stegpaar 2a aus Figur 1 mit nur einem Steg. 62' und exzentrischem Heizkanal 3.

Figur 7, 7a

eine Variante zu einem Stegpaar 2a aus Figur 1.

Figur 8, 8a

eine weitere Variante zu einem Stegpaar 2a aus Figur 1.

Figur 9, 9a

eine weitere Variante zu einem Stegpaar 2a aus Figur 1.

Figur 10

einen Längsschnitt gemäss Linie D-D aus Figur 12, durch eine rechteckige Mischer/Wärmeaustauscher-Einheit mit drei nebeneinander liegenden Rohren 1, 1', 1" in einer Ebene und einer um das Gehäuse verlängerten Wärmeträgerzuleitungskammer 4.

Figur 11

einen Querschnitt durch eine Mischer/Wärmetauschereinheit, gemäss der Linie C-C aus Figur 10 und integrierter Düse bzw. Blende 3' im Austrittsbereich des Heizkanals 3.

Figur 12

eine Draufsicht auf eine Mischer/Wärmetauschereinheit nach Figur 10 mit Anschlüssen für die Wärmeträgerzuführung 4 und -ableitung 5.

Figur 13

einen Längsschnitt durch eine Mischer/Wärmetauschereinheit mit drei in Produkt-Hauptströmungsrichtung hintereinander angeordneten Reihen von nebeneinander liegenden Rohren mit unterschiedlich dimensionierten Stegen und mit verschiedenen Rohr-Mittenabständen "a" bzw. "h" sowie definierten Spalten zur Gehäusewandung und zwischen den einzelnen Rohrebenen für die Reduzierung von Toträumen.

Figur 14

zeigt einen Querschnitt auf ein Mischer/Wärmetauscher-Einheit mit getrenntem konzentrischen Wärmezuleitungs- 4 und Wärmeableitungsbereich 5, desweiteren ist durch den Wärmezuleitungsbereich 4 eine zuführende Kapillare 13 gezeigt, als einseitige Verlängerung des Temperierkanal, um eine zusätzliche Substanz über Verteilerbohrungen 14, in den Produkthauptstrom verteilt einleiten zu können.

Figur 14a

zeigt eine Schnittdarstellung entlang der Linie A-A aus Figur 14, insbesondere sind die Verteilerbohrungen 14 zur gleichmäßigen Verteilung einer zugeführten Substanz in den Produkthauptstrom.

Figur 15

zeigt eine modular aufgebauten Mischer/Wärmeaustauscher-Reaktor mit einer Stoff-Einleitung über Kapillare 13 und Verteilung über Bohrungen 14 für die Zuführung einer Reaktionskomponente, wobei die Anordnung vier hintereinander geschaltete Mischer/Wärmetauschereinheiten (9, 9a, 9b, 9c) mit unterschiedlichen L/D-Verhältnissen hat und die Mischer/Wärmeaustauscher-Einheiten um 90 Grad verdreht zueinander angeordnet sind.

Show it:

Figure 1

a longitudinal section through the housing 6 of a mixer / heat exchanger according to the invention according to line AA in Figure 1a and the angular offset of the webs to each other and the angular arrangement of the webs to the main flow direction.

Figure 1a

Partial cross-section and side view of the tube 1 with webs 2a and 2b according to Figure 1.

Figure 2

shows a mixer / heat exchanger with two tubes 1 arranged in parallel in one plane with webs 2a and 2a 'in the region of the product flow, as well as the angular range α of the webs 2a and 2b and the angular range β of the webs to the main flow direction.

Figure 2a

shows the mixer / heat exchanger according to the line BB from Figure 2 with a supplying heat transfer chamber 4 and a discharge heat transfer chamber 5 and the angular range γ for the inclined position of the web tubes in the area of the product flow.

Figure 3, 3a

a variant of a web pair 2a from Figure 1 in cross section.

Figure 4, 4a

a further variant of a pair of webs 2a from FIG. 1.

Figure 5, 5a

a further variant of a flow-optimized web pair 2a from FIG. 1.

Figure 6, 6a

a variant of a web pair 2a from Figure 1 with only one web. 62 'and eccentric heating duct 3.

Figure 7, 7a

a variant of a web pair 2a from Figure 1.

Figure 8, 8a

a further variant of a pair of webs 2a from FIG. 1.

Figure 9, 9a

a further variant of a pair of webs 2a from FIG. 1.

Figure 10

a longitudinal section along line DD from Figure 12, through a rectangular mixer / heat exchanger unit with three adjacent tubes 1, 1 ', 1 "in one plane and a heat carrier supply chamber 4 extended by the housing.

Figure 11

a cross section through a mixer / heat exchanger unit, according to the line CC from Figure 10 and integrated nozzle or orifice 3 'in the outlet area of the heating duct 3.

Figure 12

10 shows a plan view of a mixer / heat exchanger unit according to FIG. 10 with connections for the heat carrier supply 4 and discharge 5.

Figure 13

a longitudinal section through a mixer / heat exchanger unit with three rows of juxtaposed tubes with differently dimensioned webs and with different tube center distances "a" or "h" as well as defined columns for the housing wall and between the individual tube levels for the Reduction of dead spaces.

Figure 14

shows a cross section of a mixer / heat exchanger unit with separate concentric heat supply 4 and heat dissipation area 5, furthermore a supplying capillary 13 is shown through the heat supply area 4, as a one-sided extension of the temperature control channel by an additional substance via distribution bores 14, distributed in the main product stream to initiate.

Figure 14a

shows a sectional view along the line AA from FIG. 14, in particular the distributor bores 14 for the uniform distribution of a substance supplied into the main product stream.

Figure 15

shows a modular mixer / heat exchanger reactor with a material introduction via capillary 13 and distribution via holes 14 for the supply of a reaction component, the arrangement comprising four consecutive mixer / heat exchanger units (9, 9a, 9b, 9c) with different L / D ratios and the mixer / heat exchanger units are arranged rotated by 90 degrees to each other.

Examples example 1

FIG. 1 shows a one-piece tube 1 in a housing 6 through which the product flows, which has a web area on the outer circumference and two under one Angle β = 45 or -135 ° to the radial direction of the main flow (arrow) Mixing bars 2a, 2a 'in a front, shown in section and a rear Has web area with two further webs 2b, 2b '. The width of the land area is chosen here so that alternating two web layers, each with two webs 2a, 2a 'and 2b, 2b 'are arranged radially offset from one another in the housing 6 along the tube axis and they connect seamlessly in their axial extent (see figure 1a).

The shape or design of the webs and the web surface quality can be different. The surface of the webs and the tube can e.g. structured be by raised pimples, warts or grooves or grooves to the heat transfer Enlarge area and produce additional flow effects. in the It essentially depends on the process engineering task or requirement. Examples of this are shown in FIGS. 3 to 9. The bridges can on the outer circumference of the tube 1 radially symmetrical (as in Fig. 3-5) or also be arranged asymmetrically (Fig. 7-9) and different from each other Show angles, with different web shapes combined can and correspond to Fig. 7-9. The web shape can be from the radial simple form differ in that they also have a curved Show shape as a guide vane, which is particularly advantageous if the intersect concentric areas and forced secondary flows become.

3, 3a show a cross section or longitudinal section through a tube 1 similar to FIG. 1 with two webs 32a, 32a 'which have a constant diameter and one Have flat 31 transversely to the main flow direction 21 at its ends.

4, 4a, the webs 42a, 42a 'are tapered at the end in cross section educated. The webs 52a, 52a 'according to the variant according to FIGS. 5, 5a are similar 4, but with a widened foot corresponding to the diameter of the tube 1 executed.

Fig. 6 shows a variant of a web tube 1 similar to that of FIG. 5, but with only a web 62 'in a web position. 7 combines web shapes 4 and FIG. 5 here with different radial expansion of the webs 72, 72 '. 8, which is similar to FIG. 7, both webs 82, 82 ' in cross-section and at an angle of 170 ° C around the pipe axis rotated to each other arranged.

In the variant according to FIG. 9, the angular offset is 90 ° C. between the webs 92 and 92 'compared to the arrangement of FIG. 7.

Due to the shape and arrangement of the webs, the heat transfer surface can the side in contact with the product and also the flow around the pipe and thus also the important mixing process are favored. Especially with temperature control processes of highly viscous media with a viscosity greater than 1 Pa.s is a defined one Arrangement of the webs on the outer circumference of the tube makes sense to next to the Heat transfer can also achieve an effective mixing effect. To increase the Heating power can be the inner contour of the web tubes 1, which is in contact with the Temperature control is also available with ribs. This will make the Heating surface on the heat or coolant side increased significantly.

The tube shape with any number or specifically arranged web areas on the outer tube diameter can be economical in the casting process or in a Forging processes are manufactured, this always ensures that a complete metallic contact between tube and raised outer contour consists . In special cases, the radial webs can be hollow, so that the web cavity has a direct connection to the temperature control room and everywhere constant wall thicknesses are present. Mechanical strength requirements and the required compressive strength is made by choosing the appropriate wall thickness.

The tubes can be made of different materials, so that one sufficiently high corrosion resistance is guaranteed.

The casting process allows economical production of only one particular one Pipe length too. Larger pipe lengths have to be connected by connecting several pipe units be produced using a suitable welding process.

Example 2

Another mixer / heat exchanger is shown in Figure 2 in longitudinal section. Six tubes 1 have two parallel layers of webs 2a and 2b with each on the outer circumference of the tubes two radially offset webs 2a, 2a '. The pipes 1 protrude at one end into a heat transfer medium supply chamber 4 and end in one Heat transfer chamber 5 (Figure 2a). The tubes 1 are with the feed 4 and the Discharge chamber 5 welded. The tubes 1 are at an angle γ of approximately 5 degrees transverse to the main flow direction 21 of the product. The tubes 1 with the webs are positioned so that the webs are at an angle β of 45 degrees to the product flow 21 are positioned. The webs 2a are in relation to the offset webs 2b in an angle α of 90 degrees.

The supply chamber 4 and discharge chamber 5 of the temperature control consist of a on the housing 6 welded pocket or a half tube (not shown).

Example 3

FIG. 10 shows a mixer / heat exchanger unit with a rectangular housing 6 and three web tubes 1, 1 ', 1 ". The webs 12a, 12b correspond in their construction the types shown in Fig. 3 and are over the length of the Pipes 1, 1 ', 1 "arranged in an alternating position.

In the cross section in Fig. 11 along line C-C of Fig. 10 it can be seen that by a outer casing 15 two chambers 4, 5 are formed, with a feed line 16 or a discharge line 17 are connected for a liquid heat transfer medium (see Fig. 12). The tubes 1, 1 ', 1 "are as shown in Fig. 11 in operation from Flows through heat transfer medium 18. At one end, the tubes 1, 1 ', 1 "have one Constriction 3 'in channel 3.

The mixer / heat exchanger (compare sectional view in Fig. 12) has one through the housing 6 formed rectangular product flow area. The further that Housing 6 surrounding housing 15, which is divided with separators, forms the Chambers 4, 5 for the heat transfer medium 18. Several shaped according to FIG. 10 Mixer / heat exchanger units are one behind the other in the direction of flow arranged and connected flush to a product line. The product flows through 10 from above (flow direction 21).

Another option for supplying and discharging the bath liquid is in that around the heat exchanger housing with internal web tubes Ring or jacket tube, which in turn has two dividers to separate between supply and return of the heat transfer medium (see figure 14), put up and welded. With a round heat transfer chamber and Housing are the temperature-controlled tubes 1 with their webs in the inflow plane of the Product of different lengths.

The shape and direction of the web can interact with the horizontal Pipe distances "a" or the vertical pipe distances "h" among each other an optimal Form temperature-controlled mixer / heat exchanger geometry with large Heat transfer surface and high mixing effect. The pipes with the outer Crosspieces can show different pipe spacings, they can be chosen so closely that the concentric land areas overlap and the outer Crossbars cross each other (see Figure 13). This allows the heat transfer Area varies per unit volume and the residence time of the product be made smaller. The tubes in one level can have different web shapes show and arrangements.

Example 4

FIG. 13 shows a mixer heat exchanger arrangement similar to that shown in FIG. 10 Shape however with two further rows of bridge tubes 131, 132, which in Product flow direction 21 are arranged one behind the other.

The first row of web tubes 1, 1 ', 1 "with webs 12 a, 12b corresponds to that in FIG Fig. 10 shape shown.

In the further rows, the tubes 131, 132 with the outer webs are arranged in such a way that the respective end webs to the housing 6 have a defined gap show in order to flow around the web tubes as completely as possible, in particular for To enable housing wall 6 (Figure 13, level 2 and 3). This gap prevents the Formation of dead spaces in the flow direction in which products are deposited can be used to reduce the quality of the products due to long temperature exposure leads. At the same time, additional temperature control takes place through the targeted Guiding the product to the temperature-controlled housing.

Example 5

The temperature-controlled mixer / heat exchanger can according to the variant Fig. 14 can be used to evenly mix in a component Distribute product. In this application, in the middle tube 13 in Area of the webs 2a, 2b introduced small inlet openings 14, which make it possible a component to be mixed in via a pipe extension (13) through the To supply heating medium room and through the openings 14 through the Enter the entire product flow cross-section evenly (Figure 14, 14a).

A combination of several mixer / heat exchangers 9, 9a, 9b, 9c into one Flow reactor is shown schematically in section in FIG. 15. The unit 9a has here an L / D ratio of 1.5 while the remaining units of the reactor L / D ratio of 0.75. The units are offset from each other by 90 degrees arranged. The incoming heat transfer chambers 4 and dissipative heat transfer chambers 5 of the mixer / heat exchanger units are all in parallel with the Heat transfer supply connected. The temperature control tubes 1 with webs are in the Units 9, 9b by broken lines and in units 9a, 9c by the Crossing points of the broken lines are indicated. It can be seen that the Units in the horizontal and vertical planes or in the main flow direction Have 21 different number of web tubes for temperature control in order to Module to achieve a differentiated temperature control and dispersion performance. In unit 9, the middle tube is only open on one side (similar to the version in FIG. 14 a) and through a capillary 13 on one side through the temperature control chamber 4 extended to outside the mixer / heat exchanger unit 9. Outside the Unit 9 can now connect a metering pump, which is not shown in FIG. 15 to e.g. another substance (additive, entrainer, reactants) over the entire flow cross-section of the module or unit dose and distribute. Bores or nozzles 14 along the tube in the product stream ensure an even distribution over the flow cross-section the unit.

Depending on the volume flow of the heat transfer medium (e.g. hot water, oil, cooling brine) it is necessary to narrow the cross-section or to see a nozzle (orifice) in front, so that webs with the same flow flow in parallel Energy density are supplied. The simplest version is the inside diameter 3 of the pipe in the outlet area to the dissipating heat transfer chamber reduced in size over a short distance, e.g. on the inside diameter 3 ', similar to in Figure 11 is shown. If steam is used as an energy source, this narrowing is of the inner diameter 3 of the tube 1 is not required.

Example 6 Compact heat exchanger

Compact heat exchangers have the task of flowing through in a short time Medium as high as possible, i.e. heat as close as possible to the heating medium temperature, so that due to a short-term temperature load no thermal Damage to the product occurs. Compact heat exchangers are designed to have smaller apparatus dimensions have, as known heat exchangers with the same performance, thus only a small space requirement in a process engineering plant and this results in low installation and investment costs. An essential feature to compare different types of heat exchanger is the heat transfer performance, the required heat exchange surface and the product side Apparatus volume. The mixer / heat exchanger according to the invention was also used a device from the prior art (published patent application DE-2 839 564 A1) compared. The investigated mixer / heat exchanger according to the invention corresponded basically the embodiment shown in FIGS. 2 and 2a, but with four instead of two pipes arranged next to each other across the product flow direction and overall Nine instead of three arranged one behind the other in the direction of flow 21 Pipe bundles (see Figure 2a).

For the experiment, a highly viscous substance (silicone oil) with a viscosity of 10 Pa.s was selected and pumped through the heat exchanger with a gear pump, so that the mass flow could be determined gravimetrically in the outlet area of the respective apparatus. For the test, the heat exchangers were connected to an electrically heated and controlled thermostat (heating output 3 kW). Water was selected as the heat transfer medium so that the thermostat controller for the flow temperature at the thermostat was set to 90 ° C. The inlet and outlet temperatures of the heat transfer medium and the product side were measured using a Pt-100 thermocouple and registered and saved on a data acquisition system. In addition, pressure sensors registered the pressures occurring in the inlet and outlet areas of the temperature control and product side as a result of the flow losses occurring. The equipment characteristics of the heat exchangers are summarized in Table 1. apparatus data State of the art Mixer / heat exchanger material 1.4571 * 1.4571 Hydraulic cross section 38 x 38 mm 40 x 43 mm apparatuses length 310 mm 158 mm web width Tube 4 x 1mm 5 mm Bar areas per tube / bars per area 8 pipe parallel 8/2 Pipe diameter / inside diameter Pipe 4 x 1 mm 7 mm / 5 mm Nozzle Drchm. in the exit area -------------------- 2.5 mm Temperature control surface of the internals 0.09 sqm 0.068 sqm Tempering surface of the u. dissipative area (housing portion) 0.00 sqm 0.012 sqm

The apparatus data show design-related deviations. From table 1 is It can be seen that the mixer / heat exchanger has a shorter design and therefore has a lower volume on the product side (hold-up). In addition, the Mixer / heat exchanger an effective heat transfer area smaller by 0.01 qm. Due to the design, there is always a section in the mixer / heat exchanger of the housing tempered. The effective total temperature control area is for the test evaluation been used. From the tests carried out, the measured Temperatures and pressures, the characteristic data were calculated and compared in Table 2 for both heat exchangers. It the transferred heat output, the average heat transfer coefficient and the pressure loss was calculated from the recorded measured values.

Table 2 shows the calculated performance data of the heat exchangers for a constant volume flow (silicone oil) of approx. 30 l / h. Stand d. technology Mixer / heat exchanger Heat transfer performance 400 W. 520 W. Product inlet temperature 22.6 ° C 22.5 ° C Product exit temperature 55.2 ° C 67.3 ° C Average heat transfer coefficient 98 W / qm / K 160 W / qm / K Pressure drop (product page) 1.5 bar 1 bar

The result of the tests confirms the higher performance of the invention compact mixer / heat exchanger. It was at constant volume flow and reduced dwell time in the heated zone approx. 120 watts more, although the heat transfer area in contact with the product is smaller than in the well-known heat exchanger. Due to the compact design of the Mixer / heat exchanger the residence time could be halved.

The test result confirms a significant improvement in heat transfer performance with a shorter residence time through the mixer / heat exchanger according to the invention.

Claims (19)

Static mixer / heat exchanger for the treatment of viscous and highly viscous products at least comprising a housing (6) for the passage of the product, at least two temperature-controlled pipes (1), which are in particular provided with a channel (3) for the passage of a heat transfer medium, the housing being the Surrounds tubes (1), a plurality of heat exchanger webs (2a, 2b) being distributed on the circumference of the tubes (1), characterized in that the heat exchanger webs (2a, 2b) along the tubes (1) in at least two parallel positions (7, 8) are aligned and the webs (2a) and (2b) of the different layers (7, 8) by an angle α of 45 ° to 135 °, preferably from 70 ° to 110 ° to each other about the axis of the tubes ( 1) are arranged rotated and that the webs (2a, 2b) to the main flow direction (21) of the product through the housing (6) are at an angle β of ± 10 ° to ± 80 °. Mixer / heat exchanger according to claim 1, characterized in that for each web (2a) or (2b) of a layer (7) or (8) a web (2a ') or web opposite to this web on the tube (1) or (2b ') is arranged. Mixer / heat exchanger according to claim 1 or 2, characterized in that the webs (2a) or (2b) of the different layers (7) or (8) are arranged alternately over the length of the tube (1). Mixer / heat exchanger according to one of claims 1 to 3, characterized in that the angle α between the webs of the different layers (7, 8) is from 85 to 95 °. Mixer / heat exchanger according to one of Claims 1 to 4, characterized in that a plurality of tubes (1, 1 ') with webs (2a, 2b) are arranged next to one another in the housing (6) transversely to the main flow direction of the product. Mixer / heat exchanger according to one of claims 1 to 5, characterized in that the housing (6) has supply lines (4) and discharge lines (5) for a heat transfer medium, which are connected to the input or output of the channels (3, 3 ') are. Mixer / heat exchanger according to one of claims 1 to 6, characterized in that in the housing (6) in several levels one behind the other with webs (2a, 2b) provided tubes (1, 1 ') are attached. Mixer / heat exchanger according to one of claims 1 to 7, characterized in that the radial expansion of the respective adjacent webs (2a, 2b) arranged on adjacent tubes (132, 132 ') overlap. Mixer / heat exchanger according to one of claims 1 to 8, characterized in that the webs (2a, 2b) of the different layers (7, 8) along the tubes (1, 1 ', 1 ") are arranged to each other in a gap. Mixer / heat exchanger according to one of claims 1 to 9, characterized in that the radial extension of the webs (2a, 2b) is at least 0.5 times the inner diameter of the pipe (1) connected to it. Mixer / heat exchanger according to one of claims 1 to 10, characterized in that the inner wall of the tubes (1, 1 ', 1 ") have a contour to increase their surface area, in particular in the form of longitudinal ribs. Mixer / heat exchanger according to one of claims 1 to 11, characterized in that selected webs (2, 2a ', 2b, 2b') of the tubes (1) are hollow on the inside and the cavity with the channel (3) of the tube (1 ) is connected. Mixer / heat exchanger according to one of claims 1 to 11, characterized in that the tubes (1, 1 ', 1 ") are provided with a resistance heater or an electrical cooling element. Mixer / heat exchanger according to one of claims 1 to 13, characterized in that the tubes (1, 1 ', 1 ") and / or the webs (2a, 2b) are coated with a catalyst. Mixer / heat exchanger according to one of Claims 1 to 14, characterized in that the tubes (1, 1 ', 1 ") are arranged in the housing (6) in the transverse direction to the main flow direction of the product at an angle γ of at most +/- 15 ° are. Mixer / heat exchanger according to one of claims 1 to 15, characterized in that in the housing (6) in several levels one behind the other with webs (2a, 2b) provided tubes (1, 1a) and the tubes (1) of the levels have differently dimensioned webs (2a, 2b) compared to the webs of the tubes (1a) of the adjacent plane. Mixer / heat exchanger according to one of claims 1 to 16, characterized in that the mixer / heat exchanger has at least one material introduction tube arranged parallel to the tubes (1), which is provided with similar webs (2a, 2b) and a plurality of openings (14) for Has inside of the housing (6). Mixer / heat exchanger according to one of claims 1 to 17, characterized in that the tubes (1) have channels (3), in the outflow area of which a nozzle (3 ') with a smaller diameter than the channels (3) is attached. Use of the mixer / heat exchanger according to one of claims 1 to 17 for tempering viscous material systems with a viscosity of 0.001 up to 20,000 Pa.s.

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