DE10159824A1 - Ordered packing used for carrying out exothermic or endothermic reactions has flow deviating sheets arranged in longitudinal direction of reactor and parallel with heating/cooling casing - Google Patents

Abstract

Ordered packing (1) for a reactor has flow deviating sheets (A, B) arranged in the longitudinal direction of the reactor and parallel with a heating/cooling casing. Corrugated flow deviating sheets (A) are alternately arranged with planar flow deviating sheets (B) forming flow deviating channels (2). The flow deviating sheets (A) completely fill the cross-section of the reactor and the flow deviating sheets (B) expose an edge gap (3) on the inner wall of the reactor. Preferred Features: The edge gap is formed in a non uniform manner over the cross-section of the reactor having the largest possible radial extension in regions of the inner wall of the reactor into which flow deviating channels protrude and having the smallest possible radial extension in which flow deviating channels do not protrude. The flow deviating channels contain inert material and/or catalyst material.

Description

The invention relates to an ordered packing for a reactor and a use.

Ordered packs, that is, systematically structured with regular geometry Packs come in a variety of designs for use in Mass transfer columns as well as known in reactors.

For example, the commercially available packs such as Montz A3 and Sulzer BX several layers of fabrics - in other designs also sheets - in one Mass transfer column arranged parallel to one another in the longitudinal direction of the column, that neighboring layers form more or less sealed channels through which the fluid flows. These channels are preferably against the longitudinal direction of the reactor inclined, usually adjacent layers are inclined in different directions. These directions regularly close the same angular amount with the vertical, but with different signs, a. The channels can be straight or be curved. Instead of sheet metal or fabric layers, expanded metal layers can also be used with or can be used without perforation.

EP-A 0 785 019 describes a packing for use in a mass transfer column known, with alternately arranged first corrugated or kinked and second slightly wavy or preferably flat layers, the first with the second layers each include power conduction channels that are inclined to the vertical. Here, the less or not corrugated layers do not reach an edge zone of the Pack or have an increased gas permeability in the edge zone of the pack, especially holes. The edge zone comprises one to twenty, preferably three to ten power conduction channels. Due to this special design with an edge zone, which as Concentric volume element is understood in the outer region of the pack an increased mass transfer area between the liquid and the Counter current moving gaseous phase and thereby improved separation performance compared with the mass transfer column equipped with a comparable pressure drop known packs guaranteed. For this, the edge zone must have at least one Include Stromleitkanal.

High heat reactions are often carried out in reactors using are equipped with a double jacket through which a heat exchange medium circulates. If such reactors are equipped with ordered packings, the problem arises that the intersecting flow guide channels essentially the reaction fluid in Steer the longitudinal direction of the reactor. Especially when using the packings as a catalyst or catalyst supports for reactions are used for the sake of providing a large volume-specific surface finely structured packs preferred. This has one result in a high number of intersections of the current-conducting channels, with the result that the substance and heat transport in the longitudinal direction of the reactor predominate. Beyond that Known packs optimized for reactors with the aim of flowing through the Packed power largely uniform over the reactor cross-section to distribute. However, this also leads to poorer heat transfer at the tempered wall. However, this is necessary, especially for reactions with strong Heat tone, an isothermal temperature profile over the reactor longitudinal and transverse direction. This requires good heat transfer to the tempered wall.

The object of the invention was therefore to provide an orderly packing for a reactor To make available, which ensures good heat transport to the tempered wall, and thus avoids or at least reduces the formation of hot spots that lead to losses selectivity and catalyst life.

The object is achieved by an orderly pack for one single-phase flow reactor with a heating / cooling jacket with parallel to each other, in Current guide plates arranged in the longitudinal direction of the reactor, with a wavelength (λ) periodically kinked or corrugated baffles with flat baffles alternate, forming flow guide channels inclined to the longitudinal direction of the reactor, and wherein the kinked or corrugated baffles have the reactor cross section Fill in completely and the flat baffles have an edge gap at the Leave the inner wall of the reactor free, its maximum width measured vertically in the plane to the longitudinal direction of the reactor, smaller than the wavelength (λ) of the periodically bent or corrugated baffles, preferably less than half the wavelength of the periodically kinked or corrugated baffles.

It has surprisingly been found that the design of the orderly packing a targeted increase in turbulence near the wall, the means in the area where the heat can be transferred is reached.

For this it is necessary to design the marginal gap narrowly, with a maximum Width, measured in the plane perpendicular to the longitudinal direction of the reactor, smaller than that Wavelength λ of the periodically kinked or corrugated baffles, preferred smaller than half the wavelength of the same.

The ordered packing according to the invention comprises, alternating with flat current plates arranged, with a wavelength λ periodically kinked or corrugated baffles. In this case, the distance between two is known as the wavelength λ in a known manner successive maxima of the waves or kinks. Thus, the Edge gap according to the invention less than one flow conduit on the inner wall of the reactor, preferably less than half a Stromleitkanal.

The packing according to the invention is for a single-phase reactor trained, that is, for a reactor that is either exclusively of a gas phase or flows through a liquid phase.

The reactor is equipped with a heating / cooling jacket, that is, with an outer one Double jacket through which a heat exchange medium circulates, depending on the type to be carried out Reaction, absorbs or releases heat of reaction.

The invention is not restricted with regard to the geometric shape of the Reactor cross section. The reactor cross section can preferably be round or rectangular be trained.

According to the invention, the maximum width of the marginal gap is now measured in the plane perpendicular to the longitudinal direction of the reactor, smaller than the wavelength of the periodically kinked or corrugated baffles. The invention is in principle not restricted regarding the lower limit for the maximum width of the marginal gap, this is only production technology and due to the minimum throughput through the reactor. The The lower limit can be up to 0.05 times the wavelength, in particular up to 0.1 times the wavelength of the waves or kinks of the baffles.

The fact that the Stromleitkanäle to the reactor longitudinal direction, due to the orientation of the Kinks or waves are inclined, there will be areas of the inner wall of the reactor in which Power conduction channels open to the inside of the reactor and areas in which none Current conduction channels open to the inside of the reactor.

The flat current-conducting plates are preferably designed in such a way that they Areas of the inner wall of the reactor in which current-conducting channels open out are larger Leave the marginal gap opposite the areas of the inner wall of the reactor in which none Stromleitkanäle open. Such a formation of the marginal gap is particularly for a reactor with a round cross section is suitable. It enables further optimization the flow of the reaction fluid in the package and thus another Improvement of the heat transport to the tempered wall.

The edge gap is preferably shaped in such a way that the smallest radial extent is zero. This allows the flat baffles in a simple manner Be centered.

In a preferred manner, the locations at which the smallest radial extent of the Edge gap is zero, that is, on which the flat baffles up to When viewed in the longitudinal section of the packing, the inner wall of the reactor is sufficient to be punctiform. For this purpose, the flat baffles on the adjacent to the inner wall of the reactor Pages jagged or curled.

The pack according to the invention preferably has an angle of inclination Flow guide channels to the longitudinal direction of the reactor from 20 to 70 °, in particular from 30 to 60 °. For good heat transport to the tempered wall, larger ones are in the above values mentioned above are particularly suitable.

In a preferred embodiment, the marginal gap is non-uniform over the reactor height trained, both a continuous and a discontinuous Changing the width of the edge gap over the reactor height is possible. Through the Variation of the marginal gap over the reactor height is an adaptation to the temperature profile the respective reaction is possible by entering in areas with great heat increased heat transport to the tempered wall is guaranteed and accordingly in Areas with less heat toning the heat transfer to the tempered wall is reduced in favor of a lower pressure drop.

It is also possible to change the shape, wavelength and / or amplitude of the kinks or waves of the current baffles over the reactor length and / or over the To design the reactor cross section variably. This allows the shape of the channels to match specific conditions of the reaction to be carried out.

Preferred cross-sectional shapes of the current-conducting channels in the package according to the invention are triangular, rounded, rectangular or trapezoidal.

Known ordered packs are usually constructed in such a way that the Conductor ducts between a bent or corrugated conduction plate and the adjoining flat current conducting plate are formed opposite the current conducting channels, those formed with the next following kinked or corrugated baffle are inclined in different directions that are regular with the vertical Form the same angle, but with a different sign. In contrast is an embodiment is preferred for the pack according to the invention, according to which two or several consecutive kinked or corrugated baffles the same Have orientation. Such configurations have the advantage of another Improvement of the heat transport to the tempered wall.

The ordered packing can be designed as a catalyst or catalyst carrier.

It is possible to introduce catalyst material into the flow guide channels. This allows the Heat transfer to the tempered wall, while reducing the Pressure loss compared to a bed of catalyst material can be improved. The The catalyst material introduced can, for example, in the form of a fleece, in particular of a fleece with a large specific surface area, as for example in Form of an open-pore metal foam. It can be a supported one Catalyst material, in particular an active material applied to balls or around a Trade fully catalyst material.

The orderly pack can equally be used to carry out exothermic or endothermic reactions are used, preferably to carry out Partial oxidation, selective hydrogenation or aerosol hydrogenation.

The invention is based on a drawing and from Embodiments explained in more detail.

It show in detail

Fig. 1 shows a cross section through a first embodiment of a structured packing according to the invention, with different geometrical configuration of the lip gap in Fig. 1a and 1b, respectively,

Fig. 2 is a schematic representation of a structured packing in longitudinal section with continuous variation of the width of the edge gap over the packing height in Fig. 2a and discontinuous variation in Fig. 2b,

Fig. 3 are schematic views of different structural forms of the rippled or corrugated Stromleitbleche A (Fig. 3a to 3d),

Fig. 4 are schematic representations of flat baffles B in longitudinal section, each with different shapes in the edge region ( Fig. 4a to 4c) and

Fig. 5 shows another embodiment of a package according to the invention.

The cross-sectional view in FIG. 1 shows, by way of example, an ordered packing 1 with alternately arranged corrugated baffles A and planar baffles B, which form electricity baffles 2 , the corrugated baffles A completely filling the reactor cross section and the baffles B leaving an edge gap 3 on the inner wall of the reactor. From the simplified illustration in FIGS. 1a and 1b, it can be clearly seen that the edge gap 3 is in each case non-uniformly formed over the reactor cross-section, with different geometric configurations being possible, for example a crescent-shaped configuration in FIG. 1a or an configuration in the form of circular sections as in Fig. 1b.

Fig. 2 shows a schematic representation of a longitudinal section through an ordered packing, for clarification only one flat current baffle B is shown for clarification, with continuously varying width (in Fig. 2a) or with discontinuously varying width (in Fig. 2b ). As a result, the edge gap 3 is formed non-uniformly over the package height.

In FIG. 3a to 3d different structure of the rippled or corrugated Stromleitbleche A are shown schematically: a triangular relief form in Figures 3a, corrugated embossing form in Figure 3b, a rectangular embossing form in Figure 3c or trapezoidal relief form in Fig. 3d....

FIG. 4 shows schematically longitudinal sectional representations of planar baffles B, each with a different design of the edge regions, that is to say the regions in which the planar baffles B extend as far as the inner wall of the reactor. The geometric configuration can preferably be corrugated ( FIG. 4a), serrated ( FIG. 4b) or angled at a right angle ( FIG. 4c).

FIG. 5 schematically shows an ordered package with kinked current baffles A and flat current baffles B, a filling of inert and / or catalyst material being introduced into the current conducting channel 2 .

Examples

In a laboratory apparatus, comprising a tubular measuring section with a length of 200 mm and an inner diameter of 25 mm with a double jacket was equipped, via which the inner wall of the measuring section was heated to 100 ° C with water vapor was one of alternately arranged levels and with an amplitude of 1 mm and a wavelength of 4 mm periodically corrugated baffles, each made of Kanthal®, the four arranged one above the other, each rotated 90 ° against each other Pack sections formed, loaded. The measuring section was filled with air from below Flowing to room temperature, the measuring section over the four pack sections through her. Both at the inlet and at the outlet of the air from the measuring section measured their mean temperature.

The total radial heat transfer coefficient α _{tot was} determined from these mean temperature measurements.

Comparative Examples V1 to V3

With the arrangement described above, the radial was first Total heat transfer coefficient of the measuring section, in which a pack is made exclusively periodically waved with an amplitude of 1 mm and a wavelength of 4 mm Baffles, without flat baffles, measured pack. Here, the Air throughput, as listed in the table below, from comparative example V1 increased over comparative example V2 to comparative example V3. The measured Pressure drops and from the difference in mean air temperatures between Radial calculated exit and entry into the measuring section Total heat transfer coefficients are listed in the table below.

Examples 1.1 to 1.3

The experimental set-up was modified compared to the comparative experiments in that than in addition to the periodically with an amplitude of 1 mm and a wavelength of 4 mm corrugated baffles alternatingly flat baffles were installed under Release of a concentric marginal gap from the inner wall of the measuring section with a Width of 2 mm, i.e. corresponding to half the wavelength λ (4 mm) of the corrugated Baffles. The throughputs corresponding to the comparative examples were run. In the table below, the pressure losses measured in each case as well as those via the measured temperature differences calculated radial Total heat transfer coefficients listed.

Examples 2.1 to 2.3

The experimental setup differed from Examples 1.1. to 1.3 insofar as the flat guide plates leave a narrower concentric marginal gap on the inner wall of the measuring section of 0.4 mm, corresponding to 1/10 of the wavelength (4 mm) of the corrugated guide plates. The measured or measured and calculated values for the pressure losses or radial total heat transfer coefficients at different air flow rates are listed in the table. table

The test results show that with decreasing marginal gap, with the same Throughput of a single-phase, gaseous medium (air) through the measuring section of the radial total heat transfer coefficient increases sharply.

Claims (10)

1.Ordered packing ( 1 ) for a single-phase flow reactor with a heating / cooling jacket with current baffles (A, B) arranged parallel to one another in the longitudinal direction of the reactor, with periodically kinked or corrugated current baffles (A) with flat current baffles with a wavelength (λ) (B) alternate, with the formation of flow guide channels ( 2 ) inclined to the longitudinal direction of the reactor, and wherein the bent or corrugated flow guide plates (A) completely fill the reactor cross section and the flat flow guide plates (B) leave an edge gap ( 3 ) on the inner wall of the reactor, the maximum width of which , measured in the plane perpendicular to the longitudinal direction of the reactor, is less than the wavelength (λ) of the periodically kinked or corrugated baffles (A), preferably less than half the wavelength of the periodically kinked or undulated baffles (A). 2. Ordered packing ( 1 ) according to claim 1, characterized in that the marginal gap ( 3 ) over the reactor cross-section is non-uniform in such a way that it has the greatest radial extent and in. In areas of the reactor inner wall in which flow guide channels ( 2 ) open Areas in which no current-conducting channels ( 2 ) open out and have the smallest radial expansion. 3. Ordered packing ( 1 ) according to claim 1 or 2, characterized in that the smallest radial extent of the edge gap ( 3 ) is zero. 4. Ordered packing ( 1 ) according to one of claims 1 to 3, characterized in that the angle of inclination of the flow guide channels ( 2 ) to the longitudinal axis of the reactor is 20 to 70 °, preferably 30 to 60 °. 5. Ordered packing ( 1 ) according to one of claims 1 to 4, characterized in that the edge gap ( 3 ) is non-uniform over the reactor height. 6. Ordered packing ( 1 ) according to one of claims 1 to 5, characterized in that the cross section of the current conduction channels ( 2 ) is triangular, rounded, rectangular or trapezoidal. 7. Ordered pack ( 1 ) according to one of claims 1 to 6, characterized in that two or more successive baffles (A) have the same orientation. 8. Ordered pack ( 1 ) according to one of claims 1 to 7, characterized in that it is constructed from two or more pack sections, successive pack sections being rotated relative to one another by 90 ° and the height of each pack section preferably being 0.5 to 20 times the inner diameter of the reactor, preferably 1 to 5 times the inner diameter of the reactor. 9. Ordered packing ( 1 ) according to one of claims 1 to 8, characterized in that in the flow guide channels ( 2 ) inert material and / or catalyst material is introduced. 10. Use of an ordered pack ( 1 ) according to one of claims 1 to 9 for carrying out exothermic or endothermic reactions, preferably partial oxidations, selective hydrogenations or aerosol hydrogenations.