DE102012220926A1 - Fixed Bed Reactor - Google Patents

Abstract

The invention relates to a reactor (1) with radial flow through it for carrying out chemical-catalytic reactions with an isothermal reaction regime. According to the invention, the reaction space (7) of the reactor (1) is penetrated by a multiplicity of heat exchange tubes (9), the heat exchange tubes (9) being arranged largely parallel to the central axis (6) and in a plurality of groups, so that the rows of full rows (38) form, which are arranged in the reaction space (7) in the radial direction, wherein the outer contours of adjacent heat exchange tubes (9) a row (38, 39) are so close to each other that radial flow channels (40) are formed.

Description

The invention relates to a radially flowed fixed bed reactor.

Fixed bed reactors are reactors for carrying out chemical reactions, wherein a fluid flows through a catalyst located in a fixed bed axially or radially.

From the prior art a variety of fixed bed reactors are known. Of particular interest are radially through-flow fixed bed reactors. With this design, it is possible to create a large flow area at low pressure loss. Heat exchangers are frequently provided in the reactors in order to remove or supply heat in order to provide constant reaction conditions in the case of exothermic or endothermic reactions.

So will in the EP 2 165 755 A1 an isothermal chemical reactor comprising heat exchange elements having a plurality of heat exchange elements arranged around the reactor axis and each consisting of a radially aligned series of a plurality of parallel axially extending heat exchange channels. The channels of a heat exchange element are each connected to a manifold or to a manifold with continuously variable cross-section. The heat exchange channels have an elongate cross section with approximately oval or rectangular shape and a different lateral orientation within a heat exchange element. The integration of each channel with non-circular cross-section of the perpendicular to him distributor or manifold is technically demanding, and thus again costly. In addition, only a limited heat exchange surface density can be achieved by design.

In the publication DE 100 31 347 A1 a cylindrical reactor is presented with radially arranged heat exchanger plates, wherein the heat exchanger plates can also be designed wedge-shaped. Due to the design, the maintenance and repair of such apparatus is expensive. The uniform distribution of the heat exchange medium in the heat exchanger plates requires special care. The production of heat transfer plates, especially when required pressure stability or variable plate thickness, is complicated and therefore costly.

Also in the EP 2 363 203 A1 discloses a reactor with heat transfer plates having a plurality of adjacent channels for transporting the heat carrier. Due to their complicated construction, these heat transfer plates are expensive to manufacture and, due to their filigree structure, are susceptible to mechanical, in particular compressive stress.

The DE 10 2009 031 765 A1 discloses a cylindrical converter for carrying out exothermic catalytic reactions in which wedge-shaped heat panels are used to dissipate the heat of reaction. The heat panels are specially adapted to a cooling system with an evaporating medium. In this system, the vaporized heat carrier releases its heat in a heat exchanger located in the converter itself to a heat carrier of a secondary heat carrier circuit. These heat panels are costly in their production due to their complicated structure to ensure the pressure stability.

Object of the present invention is to propose a radially flowed through fixed bed reactor for chemically catalytic reactions, even under elevated pressure, with heat of reaction, which is inexpensive to manufacture and very easily tuned to different reaction courses and different amounts of released or required heat of reaction to create isothermal reaction conditions as possible can be.

According to the invention the object is achieved by a reactor having the features of the main claim. Preferred embodiments of the invention are the subject of the dependent claims.

The reactor according to the invention is suitable for carrying out chemically catalytic reactions with evolution of heat with the most isothermal reaction conditions possible.

In principle, the shape of the reactor is cylindrical with a substantially circular cross section, so that this shape defines an axial (in the longitudinal direction of the cylinder) and a radial direction (in the circular cross-sectional area from the center to the outside). The central axis of the reactor is arranged centrally in the circular cross-section in the axial direction. In use, the reactor is upright, i. the axial direction is vertical.

The reactor has a cylindrical reactor shell arranged around the central axis, which is preferably pressure-stable and which is closed at its upper end by an upper hood and at its lower end by a lower hood. The entirety of reactor shell and upper and lower hood is referred to in this document as a pressure jacket.

Within the reactor shell is a substantially annular reaction space, which encloses a perforated central tube. With the The phrase "substantially" is expressed to mean that a circular shape is preferred, but small deviations, eg, due to manufacturing tolerances, are permissible.

The annular reaction space is enclosed by an outer cavity, wherein the outer cavity and the reaction space are separated by an at least partially perforated outer wall. For the use of the reactor, a catalyst bed is filled into the reaction space. Inside the central tube an inner cavity is defined.

The outer cavity and the central tube are provided for supplying the feed gas and for discharging the product gas, wherein it depends on the concrete reaction to be carried out, whether the supply is via the central tube and the discharge through the outer cavity or vice versa. The feed of the feed gas or discharge of the product gas takes place through the perforated regions of the inner and outer walls delimiting the reaction space. The inflow and outflow allow the radial gas flow.

Perforated here expresses the gas permeability of the outer wall of the reaction chamber and the central tube (the inner wall of the reaction chamber), so that the reaction gas can penetrate this, but the catalyst located in the reaction chamber is retained. The perforation can be ensured in a variety of ways, e.g. through a wall with interruptions, e.g. in the form of holes or slits, or a wire mesh. The hole size must be matched to the particle size of the catalyst to be filled. It must also be ensured that catalyst particles do not clog the perforation. Optionally, this can be provided a multi-layer wall, the layers are also advantageously arranged spaced by spacers.

The dimensions of the reactor according to the invention are not particularly limited and are determined depending on the respective required production capacity. In commercial use, it is generally desirable for economic reasons to dimension the reactor as large as possible. In a first step, the radial and axial dimensions of the reaction space are determined on the basis of the reaction-technical requirements. The outer reactor dimensions then result from the space requirement of the corresponding parts of the apparatus for guiding the reaction gas and the heat carrier as well as design requirements.

The outer diameters of such reactors are generally in a range between 2 m and 9 m, preferably between 3 m and 5 m. The overall height is generally in a range between 3 m and 30 m, preferably between 15 m and 25 m. However, smaller size reactors are also possible, e.g. for decentralized solutions or for experimental purposes. The central tube generally has a diameter between 0.3 m and 1.5 m. Preferred diameters are in a range between 0.6 m and 0.9 m. As a result, the central tube for the purpose of installation, maintenance or repair is walkable. Depending on the porosity and length of the porous wall on the central tube, a uniform radial flow of the gas over the surface of the porous wall is made possible. The radial dimension of the outer cavity is preferably in a range between 0.05 m and 0.5 m, preferably between 0.1 m and 0.3 m.

Furthermore, the reaction space is penetrated by a plurality of heat exchange tubes, wherein the heat exchange tubes are arranged largely parallel to the central axis and in several groups. Each group forms a full row, which is aligned in the reaction space in the radial direction. The outer contours of adjacent heat exchange tubes of a row are so close together that radial flow channels are formed by the solid rows. Full row here means that the rows cover almost the entire reaction space in the radial direction. Radial flow channels are here understood to mean channels in which the catalyst is present when the reaction is carried out and which subdivide the reaction space into radially extending sections, the tube rows largely preventing crossflows to adjacent channels as channel boundaries.

The radial direction of the flow channels or the full rows is understood in this context not only the exact radial direction from the central axis to the outside. For certain reactions, it may be advantageous if the reaction space is not traversed by the reaction gas by the shortest route, but e.g. slightly oblique or serpentine. The term "radial flow through the reactor" means flows which flow through the reactor in the radial direction, but these may also be directed slightly obliquely, ie with an axial portion.

The outer contours of adjacent heat exchange tubes of a row preferably have a distance of less than 5 mm, preferably less than 3 mm, more preferably less than 2 mm and particularly preferably less than 1 mm, with direct contacting abutment being particularly advantageous.

The withdrawal of the product gas or the supply of the feed gas can be carried out laterally through the reactor jacket or in the region of its axial ends, ie the upper and lower hood, and there in particular in the region of the central axis.

The cross-sectional shape of the heat exchange tubes is not limited in principle. However, circular tubes are preferred since they are inexpensive to obtain and easy to process as a semi-finished product and, moreover, cost-effective automated methods for welding in the tubes are available. In addition, a circular cross-section allows for a given pressure difference, the smallest wall thickness.

The outer diameters and wall thicknesses of the heat exchange tubes are selected depending on the process requirements and flow considerations. The flow cross sections are chosen so large that a flow rate of the medium is achieved, which ensures a sufficient heat transfer in exothermic or endothermic reactions, which means that the heat of reaction can be safely removed in exothermic reactions or in endothermic reactions necessary for the reaction Heat is supplied and the pressure losses remain in an economic context. Conventional outer diameter of such heat exchange tubes are in a range between 15 mm and 40 mm, preferably between 20 mm and 30 mm. The wall thicknesses are generally between 1.0 mm and 4.0 mm, preferably between 1.5 mm and 2.5 mm. The material is selected primarily depending on the maximum temperatures during overall operation and chemical resistance. As a rule, non-alloyed or low-alloyed boiler tube steels and in special cases also stainless steels are used.

The distance of the full rows with each other and their arrangement to each other are dependent on the desired reaction conditions. Thus, the design of the arrangement of the rows of heat exchange tubes in the reaction chamber depends on the course of the reaction in the flow direction and on the degree of heat of reaction. By adapted to a reaction arrangement of the heat exchange tube rows, the isotherm is ensured in the reaction chamber. The heat exchange surface density is adapted to the reaction conditions. By setting intermediate rows or using different pipe diameters, the heat exchange surface density can be increased.

The heat exchange tubes are suitable for the flow of various heat carriers, e.g. Water, oil, steam or molten salt and are in circulation with another heat exchanger, which is preferably arranged outside of the reactor shell.

The course of the reaction depends on several factors. It is significantly influenced by the pressure, the temperature and the composition of the reaction gas, the residence time of the reaction gas in the catalyst bed and the composition, size and shape of the catalyst. The residence time depends on the volume flow of the reaction gas and on the cross-sectional area of the flow-through channel. The temperature is determined by the heat transfer at the channel walls, the heat transfer in turn depends on the flow velocity in the channel and the type of wall surface. By an appropriate definition of the size and arrangement of the heat exchange tubes according to the invention, therefore, an optimal reaction sequence can be set.

Advantageously, such a reactor is provided, which is particularly flexible adaptable to the required reaction conditions of various reactions. So only the arrangement of the heat exchange tubes must be adjusted in the reaction chamber. Thus, the heat exchange surface density can be adjusted flexibly and easily. Due to the structured surface of the radial flow channels formed, in addition, swirling of the reaction gas in this area is generated, which advantageously supports the heat exchange. Also advantageous are (in particular circular) tubes pressure-stable, so that this requirement is met in a cost effective manner.

A person skilled in the art can easily carry out the design of the reactor, in particular the adaptation of the abovementioned factors to the reaction conditions intended for a particular reaction.

At least one heat exchange tube of a group is preferably simply or preferably doubly cranked at at least one tube end and fastened at least on one side in a tube plate. Preferably, the tubes are double cranked in opposite directions, so that the offset causes a misalignment without changing the entrance angle into the tube sheet, so that the connection in the tube plate continues to take place in the axial direction.

The heat exchange tubes are guided through holes in the tubesheet and the pipe ends sealingly connected to the tube sheet, in particular welded. The welding is preferably carried out in automated processes by means of arc welding or laser welding. Thus, the heat exchange tubes are fixed in position and position in the tube sheet.

Preferably, all heat exchange tubes are fixed on one side in a tube plate, particularly preferably in a tube plate at each end. Preferably, two tube sheets are provided.

Due to the offset caused by the offset lateral offset of the pipe ends they can be connected in the tube plates to the heat transfer circuit without hindering despite the small distances of the outer contours of the heat exchange tubes thereby. There are various possibilities for the configuration of the offset, for example, the tubes of a group can be alternately cranked to the right and left, or alternately cranked to the left (or right) and straight (without crank) configured.

Another advantageous effect of the cranking is the increased stability of the tubesheet. Thus, attachment of the heat exchange tubes without cranking leads to a segmentation of the soil through the boreholes. By the offset is advantageously achieved that the holes are spaced and thus the tube sheet is not segmented and the holes do not merge into one another and thus form a comb-shaped slot.

Although the tubes are preferably attached at their respective ends in a single tube sheet, but this does not preclude that the tube plates can also be multi-part one side, such as in the DE 20 2007 006 812 U1 presented.

In an alternative embodiment, the tubes may also have a smaller pipe diameter at their ends, so that a distance between the outer contours is present, which allows a professional connectivity.

Further preferably, further groups of heat exchange tubes are arranged between the rows of heat exchange tubes, forming shorter intermediate rows. Preferably, the intermediate rows start on a radius between the central tube and the outer wall and extend to the outer wall. Advantageously, the heat exchange effect in the outer region of the reactor can be increased by the intermediate rows.

In a preferred embodiment of the invention several full rows of heat exchange tubes are arranged in a star shape and symmetrically around the central tube. These extend preferably from the central tube to the outer wall.

In the region of the central tube and / or in the region of the outer wall, adiabatic zones may be provided, in the region of which no heat exchange tubes are arranged, the proportion of the catalyst volume in these adiabatic zones being process-dependent. Alternatively or additionally, an adiabatic intermediate zone which is annular in a central region of the reaction space may be provided. The proportion of the catalyst in the adiabatic zone in the region of the central tube and in the annular adiabatic intermediate zone on the total catalyst volume should preferably not exceed 5% in each case, in the adiabatic zone in the region of the outer wall this may be up to 10%, depending on the reaction. be.

Preferably, the heat exchange tubes have a continuous circular cross-section. Such pipes are inexpensive and very readily available as a semi-finished product. In an alternative embodiment, the heat exchange tubes have a circular cross-section at their ends and an elongated (for example oval or n-angular) cross-section in the middle region. Thus, the connection and the fastening in the tube sheet due to the circular cross-section can be carried out as described above. The elongated cross section in the central region of the heat exchange tubes is very well suited for certain processes. If the transverse axes of these tubes are large enough in the radial direction, the distances of the tubes in the tubesheet can become so great in straight tubes that the welds of adjacent tubes no longer influence each other. On a bend of the tubes can be dispensed with in this case.

Furthermore, the heat exchange tubes within a group preferably have varying cross sections. Here there are various alternatives, the selection of which is based on the process-specific conditions, for example: alternately large and small circular diameter within a group or larger diameter in the outer region and smaller diameter in the inner region of the reaction space.

By arranging the rows of heat exchange tubes (full rows and intermediate rows), the geometry of the radial flow channels (gas-flowed catalyst columns) is specified.

Preferably, the distance between the outer contours of adjacent full rows or adjacent full and intermediate rows increases from the central tube to the outside. Such a design is particularly suitable for gasoline synthesis.

In the course of a reaction with decreasing conversion in the flow direction (for example synthesis of hydrocarbons from methanol or from dimethyl ether / methanol mixture or from a mixture of alcohols), the radial flow channels are designed so that they become wider in the flow direction. As a result, the cooling effect in the inlet region of the gas is greatest and is lower in the flow direction to the outlet. With this kind of reaction, a discontinuity at the inner beginning of an intermediate row (smaller pipe diameter at the beginning of the intermediate row) is advantageous because it optimally utilizes the space between the solid rows to accommodate the heat exchange surface.

Other reactions, such as reactions with a constant flow reaction (e.g., syngas synthesis from synthesis gas), require parallel flow channels, e.g. be obtained by becoming larger outward pipe cross-sections. As a result, the cooling effect is constant in the flow direction of the reaction gas.

• – eine Schädigung des Katalysators durch Überhitzung wird verhindert;
• – unerwünschte Nebenreaktionen durch örtliche Überhitzungen im Reaktionsraum werden vermieden;
• – die Zwischenregenerationszyklen bei regenerierbaren Katalysatoren werden länger;
• – die Lebensdauer des Katalysators wird erheblich verlängert;
• – die Produktselektivität und -ausbeute erhöhen sich.

Thus, the heat dissipation in each area of the reaction space is adapted to the course of the reaction by the targeted distribution of the heat exchange surfaces. This results in the following advantages:

• - Damage to the catalyst due to overheating is prevented;
• - unwanted side reactions caused by local overheating in the reaction space are avoided;
• The intermediate regeneration cycles with regenerable catalysts become longer;
• - the life of the catalyst is considerably extended;
• - Product selectivity and yield increase.

In order to allow a good fillability of the reactor with the catalyst, the minimum distance between two (full or intermediate) rows is at least 15 mm, preferably 20 mm.

Preferably, the axes of the heat exchange tubes are at least one full or intermediate row on a radially outwardly directed straight line.

In an alternative embodiment, the axes of the heat exchange tubes of at least one full or intermediate row form a serpentine line. By this arrangement, turbulent flow rates are favored in the field of heat exchange tubes.

To increase the turbulence of the flow of gases through the reaction space, the heat exchange tubes may have turbulence generators on their outer contour. The turbulence generators are arranged only in regions of the outer contour, so that the turbulence generators protrude into the flow channel. No turbulence generators are provided between the heat exchange tubes. Also in the interior of the heat exchange tubes can be provided to increase the turbulence in the flow with heat transfer and thus also to increase the heat exchange turbulence generator.

The heat exchange tubes are connected to at least one, preferably both ends, with a distributor or a collector. The collecting device collects the heat transfer medium emerging from the heat exchange tubes and the distribution device distributes the heat transfer medium to the heat exchange tubes. These distribution or collection devices are preferably formed from the tube plate to which the heat exchange tubes are attached, and from a hood which spans this tube plate.

The collecting device (also referred to as heat carrier collector or collecting hood) is usually associated with a heat exchanger, which is preferably arranged outside the reactor. Advantageously, the heat exchange circuit thus formed can be used for cooling and heating. Thus, it is possible, for example when starting the reactor, to supply heat in order to reach the process temperature faster. When the reaction starts, cooling is then carried out to maintain the optimum process temperature for the exothermic reaction.

The supply and discharge of the heat carrier from / to the heat exchanger to / from the reactor preferably takes place via a loop, which is preferably also outside the reactor. The ring lines have several connections to the distribution or collection device. Preferably, four compounds are provided.

Optionally, the distribution device may also have a device for flow equalization, for example a perforated plate, in front of the tube plate.

The specific embodiments of distribution or collection devices, the loop and the heat exchanger are particularly dependent on the heat transfer medium used. The reactor according to the invention is suitable for most heat transfer media, these are in particular water, oil, steam and molten salts.

For example, for a reactor for gasoline synthesis, molten salt is provided as a heat carrier having the following composition: potassium nitrate (53% by weight), sodium nitrite (40% by weight) and sodium nitrate (7% by weight).

During operation, there are different thermal expansions of the reactor shell and the heat exchange system therein, consisting of heat exchange tubes, manifolds and collectors and the corresponding feedthroughs from the reactor. To avoid undue stress between these groups of apparatus compensators, preferably on the upper passages of the heat carrier from the Reactor, provided. Preferred are corrugated pipe compensators. The compensators may in principle be outside or inside the reactor, with an arrangement outside the reactor being preferred.

Preferably, the perforation of the central tube and / or the outer wall of the reaction space over the axial length of the reactor vary, with the aim of a uniform distribution of the feed gas into the reaction space at each axial point of the catalyst bed.

Between the heat exchange tubes in the reaction chamber, a catalyst, preferably in the form of a granular bed, filled. In the gasoline synthesis, the ratio of the heat exchange surface of the heat exchange tubes to the catalyst volume in the radial flow direction of the reaction gas (from the central tube to the outer cavity) preferably decreases. In the synthesis of methanol, this ratio preferably remains constant in the flow direction of the reaction gas. The ratio of the heat exchange surface of the heat exchange tubes to the catalyst volume generally behaves as 10 m ² / m ³ to 200 m ² / m ³ , preferably as 50 m ² / m ³ to 110 m ² / m ³ .

Preferably inert material is introduced in the upper and lower regions of the reaction space, which prevents a reaction in these regions and avoids bypass flows of the reaction gas. In the case of bent pipe ends, the structure of the flow channels is disturbed by the cranking in this area, so that a defined course of the reaction appears hardly possible in these areas. In addition, the heat exchange tubes usually extend axially out of the catalyst bed, so that a dead space forms in the uppermost region of the reaction space. In the area of the inert material and also of the dead space, the central tube and outer wall are preferably not perforated.

Preferably, the catalyst to be filled is an extrudate having a particle size between 1 mm to 2 mm in diameter and a length between 3 mm and 15 mm, more preferably between 3 mm and 6 mm in length. Particularly preferred are approximately spherical particles with a diameter of 1 mm to 3 mm, preferably 1.5 mm to 2 mm. Advantageously, the necessary size of the reactor can be reduced by a higher packing density of the catalyst, with concomitant material and energy savings. In addition, the filling of the reactor with catalyst is facilitated by a small particle size and, not least, also advantageously equalizes the gas flow.

Preferably, at least one holding grid is arranged on the heat exchange tubes between the upper and lower end, which fixes the position of the tubes relative to one another and within the reactor, thus also adjusts the width of the flow channels. This consists of a ring-spoke system. Particularly preferably, the holding grid consists of at least two concentric rings, connected by parallel to the rows of tubes and thus largely radially extending rods so that closed cassettes form around the rows of heat exchange tubes, wherein the spacings of the spokes for holding the heat exchange tubes of different diameters may vary. The rods are particularly preferred flat iron, and connected by welding. The flat bars may have interlocking grooves to facilitate assembly. Particularly preferably, the flat iron have sloping and / or rounded upper and lower edges in order not to hinder the filling and removal of the catalyst and to avoid concomitant dead zones. Advantageously, the annular adiabatic layer may coincide in the middle region with the ring of a holding grid.

The reactor is preferably accessible for maintenance and repair work. This can be done in particular via one or more manholes in the upper and / or lower hood of the pressure jacket or via the supply line of the reaction gas or the outlet line of the product gas. Particularly preferred for this purpose in the supply or discharge line is a detachable connection, e.g. a flange provided to release the conduit for entry.

The reactor preferably has a filling device for filling with catalyst. A particularly preferred filling device is described in claim 15 and has at least one catalyst distributor and a plurality of filling tubes, which are connected to this or these. The filling device is arranged above the reaction space. The at least one catalyst distributor is arranged outside the bundle of heat exchange tubes. A plurality of filling tubes, which each open into the at least one catalyst distributor with their upper tube ends, extend into a dead space formed by the uppermost region of the reaction space and open at their lower tube ends, the sequence of all filling tubes in each other in the dead space is agreed that the entirety of their lower tube ends over the entire cross section of the catalyst space is distributed.

The filling device makes use of the knowledge that, when filling the catalyst space with catalyst particles, on the one hand the time interval between two catalyst particles impinging on the same location should be sufficiently large so that the impinging catalyst particles do not tilt and jam, but have sufficient time to rotate in their own stable position and slide, and they are thereby packed as close as possible, and on the other hand, these intervals should be as evenly as possible to obtain a homogeneous homogeneous packing. With the filling tubes preferably arranged in the form of an ostrich, which extend from a catalyst distributor into the intermediate spaces between the heat exchange tubes into the catalyst-free dead space (ie the unfilled reaction space) between the underside of the upper tube plate and the top of the catalyst bed to be filled, a stationary filling device can be provided be formed, which can fill in spite of the lack of rotational and vertical movement of catalyst material so that the resulting catalyst bed in the horizontal and vertical direction is homogeneous and tightly packed. Characterized in that the course of all filling tubes in the dead space is coordinated so that the entirety of their lower tube ends is distributed over the entire cross section of the catalyst space, a uniform over the cross section of the catalyst space filling with catalyst material is ensured.

The upper ends of the filling tubes open into a catalyst distributor, so that an uninterrupted uniform flow of catalyst material to each filling tube and thus a uniform over time leakage of catalyst material from the lower ends of the filling tubes - also referred to as trickle speed - is ensured. The amount of catalyst material that passes through the filling tubes per unit time is determined by the size of the opening cross-section of the filling tubes or the inlet opening at the upper tube ends of the filling tubes. According to the desired trickling speed, the inlet openings or the inner dimensions of the filling tubes can be determined. The catalyst distributor is arranged outside the groups of heat exchange tubes, so that it can be freely designed and placed on the one hand and freely accessible on the other, whereby during the filling of the catalyst space of the catalyst manifold can be refilled by an operator readily with catalyst material. A filling device according to the invention is preferably permanently installed in the fixed bed reactor and is preferably not removed again after completion of the filling process, so that the design freedom is not limited by an expansion possibility to be provided.

After completion of the filling, the top of the catalyst bed is located at the lower tube ends of the filling tubes. Since the filling device preferably remains in the fixed bed reactor, the filling tubes and the catalyst distributor can remain filled with catalyst material, so that additional catalyst material trickles automatically into the catalyst space during reactor operation in the event of possible settling of the catalyst bed until the desired height of the catalyst bed is reached again, ie. H. until the top of the catalyst bed has again reached the lower tube ends of the filling tubes. Thus, the maintenance of the optimum height of the catalyst bed is always guaranteed.

The capacity of the filling device and the dimensions and distances of the relevant parts of the apparatus are preferably dimensioned so that even when settling the top of the catalyst bed is always safely above a predetermined minimum catalyst height. To limit bypass flows in the upper region of the catalyst bed and above, it makes sense to fill the area above the minimum height of the catalyst bed with an additional inert bed. The inert bed can also be supplied via the filling device, if the amount of catalyst is sufficient, or through the gap between the heat carrier collector and the reactor jacket or through an opening in the heat carrier collector. For this purpose, for example, the gas-impermeable upper end of the central tube can be removed for a short time. Likewise, openings can be created in the impermeable region in the outer wall of the reaction space for this filling process. The dead space below the heat transfer medium collector can be effectively minimized by an upper inert bed thus produced.

Preferably, the reactor shell forms the catalyst support. An additional component for horizontal support of the catalyst bed is thereby avoided.

In another, likewise preferred embodiment of the invention, the groups of heat exchange tubes and the catalyst bed are annularly formed with a tube and catalyst-free inner cavity, wherein the catalyst bed is supported by a radially outer and a radially inner catalyst holder and between the reactor shell and radially outer catalyst holder outer cavity is arranged. The inner and the outer cavity can be used for the supply of the feed gas or for the discharge of the product gas. In addition, reactions are avoided in the edge region of the fixed bed reactor, in which the reaction conditions can be subject to interference.

Advantageously, the catalyst support is the surface of a bed in the lower reactor hood. The construction of the fixed bed reactor is thereby simplified, since no separate component must be provided as a catalyst support.

Preferably, the catalyst manifold is disposed horizontally outside the groups of heat exchange tubes. In this way, the space can be used vertically above the heat exchange tubes for other components, such as a heat transfer manifold or collector.

In a favorable development of the invention, only one catalyst distributor is formed and extends annularly along the inside of the reactor jacket over the entire circumference. With these measures, the catalyst manifold is arranged both space-saving and freely accessible in the fixed bed reactor.

In this case, the catalyst distributor is preferably formed in cross section in the form of a trough, open into the bottom of the filling tubes and the walls are inclined to the mouth of the filling tubes. In another embodiment, the walls can also run vertically. In this way, the catalyst manifold can be structurally simple and it is ensured that all the catalyst material present in the trough reaches the junctions of the filling tubes.

In a preferred embodiment of the invention is a heat transfer manifold or collector (depending on the flow direction of the heat carrier) over the cross-sectional area of the groups of heat exchange tubes (solid or intermediate rows) and the catalyst manifold over the dead space between the heat transfer manifold or collector and the Reactor jacket arranged. With such an arrangement of heat carrier distributor or collector and catalyst distributor, the space above the heat exchange tubes is used to save space.

In this case, the upper tube ends of the heat exchange tubes are advantageously tightly welded in respective through holes of an upper tube plate and the tubesheet is the bottom of the heat carrier distributor or collector and open the heat exchange tubes in this heat carrier distributor or collector. In this way, a fixed bed reactor according to the invention can be manufactured even more cost-effectively, since a separate component for the bottom of the heat transfer medium distributor or collector is omitted.

In this case, the filling tubes each particularly preferably have a first section which extends vertically downward from the catalyst distributor between the heat carrier distributor or collector and the reactor jacket into the dead space, and a second section which extends radially inwards from the first section. In this embodiment, the first sections of the filling tubes run in a space-saving manner concentrated between heat carrier distributor or collector, d. H. upper tube plate, and reactor jacket and then distribute themselves in the form of an ostrich with its second sections above the catalyst space.

The filling tubes can also be passed in the case of multipart heat transfer manifolds and / or collectors between two heat carrier distributors or collectors. It is also possible to pass filling tubes through heat transfer manifold or collector.

In an advantageous embodiment of the invention, the lower tube ends of the filling tubes are distributed so that they each fill equal volume fractions of the catalyst bed. As a result, a largely uniform density of the catalyst bed over its entire cross-section is achieved. The catalyst bed preferably extends in the vertical direction exclusively over the area in which all the heat exchange tubes have straight sections, ie. H. not in the areas in which the radially outer heat exchange tubes are cranked.

The filling tubes preferably have an oval cross-section. Such shaped filling tubes can easily run with the smaller cross-sectional dimension in narrow spaces between heat exchange tubes and still have due to the larger in the vertical direction to larger cross-sectional dimension a sufficiently large tube cross-section in order to achieve a sufficient trickling speed and / or to avoid clogging of the tubes ,

It is advantageous if, in the operating state of the fixed bed reactor, the catalyst space, the filling tubes and each catalyst distributor are filled with catalyst material. As a result, catalyst material can trickle automatically into the catalyst space even during ongoing reactor operation in the case of possible settling of the catalyst bed and refill the catalyst bed again. The reactor operation is thus consistent with the optimum height of the catalyst bed.

Preferably, each filling tube has a throttle. In this way, the internal dimensions of the filling tubes can be chosen so that their clogging with catalyst material is excluded, and can be selected by means of the throttle, the access cross-section for each filling tube so as to give the desired trickling speed.

In this case, the size of the throttle openings is particularly preferably adjustable. As a result, the size of the throttle openings and thus the trickling speed can be readily adapted to changed conditions even during a running filling operation.

The invention also relates to the use of a reactor with in groups largely directly juxtaposed heat exchange tubes forming radial flow channels, with molten salt as heat transfer in the heat exchange tubes to achieve an approximately isothermal reaction regime. Under an approximately isothermal reaction regime is a reaction regime understood, which is a nearly constant temperature with a temperature fluctuation of max. 10 ° C, preferably max. 5 ° C, more preferably max. 2 ° C has. Particularly preferably, the use of the reactor according to the invention for carrying out an exothermic or endothermic reaction with an approximately isothermal reaction regime with molten salt is carried out as a heat carrier within the heat exchange tubes.

It is further preferred to use the reactor according to the invention for gas phase reactions, preferably exothermic catalytic or endothermic catalytic reactions. The use of the reactor according to the invention for oxidation, hydrogenation, dehydrogenation, nitration, alkylation reactions or for the production of hydrocarbons from alcohols or dimethyl ether, in particular for gasoline synthesis from methanol and methanol synthesis from synthesis gas, is particularly preferably carried out.

When used for the gasoline synthesis, the feed of the reactants via the central tube and the removal of the reaction products via the outer cavity are preferably carried out. As a heat transfer medium is preferably a molten salt is used, which is pressed in the heat transfer circuit via a bottom arranged heat transfer manifold through the heat exchange tubes in the heat carrier collector arranged above and is supplied from the collector of a heat exchanger.

The invention will be explained below with reference to embodiments and figures. Showing:

1 a longitudinal section through a reactor according to the invention,

2 a cross section through a reactor according to the invention,

3a . 3b various arrangements of tube rows,

4 a section of a retaining grid,

5a . 5b the connection of cranked and non-cranked tubes in the tubesheet in two sectional views,

6 3 a longitudinal section through an axially flowing isothermal fixed bed reactor with a catalyst filling device according to the invention,

7 a longitudinal section through a radially flowed through isothermal fixed bed reactor with a catalyst filler according to the invention, and

8a . 8b two sections through a filling device according to the invention.

The 1 shows an isothermal reactor according to the invention 1 in section. This has a pressure jacket 2 on, consisting of a cylindrical reactor jacket 3 , which at its upper end by an upper reactor hood 4 and at its lower end by a lower reactor hood 5 is completed. The reactor 1 is oriented vertically, ie the central or reactor axis 6 runs vertically. Inside the reactor shell 3 there is a reaction space 7 passing through a perforated outer wall 10 , and a central tube 13 that has an internal cavity 11 surrounds, is limited. The perforated outer wall 10 separates the reaction space 7 from an outer cavity 12 , In the reaction room 7 is a catalyst bed 8th filled. The reaction space 7 is in the axial direction (ie in the direction of the central axis 6 ) of a variety of heat exchange tubes 9 penetrated.

The axis of the gas-permeable central tube 13 is the central axis 6 , The catalyst bed 8th Thus, it extends annularly between the outer wall of the reaction space 10 and the central tube 13 ,

At the in 1 illustrated embodiment is the reactor 1 in its lower region until the beginning of the catalyst bed 8th with a lower inert bed 14a filled, on which the catalyst particles of the catalyst bed 8th rest. Above the catalyst bed 8th there is an upper inert bed 14b ,

That through the reactor 1 flowing generally to be designated reaction gas 15 depending on the place where it is located within the reactor 1 is a different composition and will be referred to differently. As a feed gas 16 it enters as a fresh, unreacted gas via a central in the lower reactor hood 5 located gas inlet line 17 in the reactor 1 one. Pressure, temperature and composition of the feed gas 16 are optimally adjusted to the specific process. The feed gas 16 flows from the gas inlet line 17 in the directly adjoining perforated central tube 13 one. From there it passes through the openings formed by the perforation 18 in the wall of the central tube in the annular reaction space 7 located catalyst bed 8th one, it as a reaction gas 15 in the radial direction and thereby reacts to the desired reaction products. After that it occurs as product gas 19 through the gas-permeable outer wall of the reaction space 10 in the outer cavity 12 one from where it is in the upper reactor hood 4 flows and from there over one, through the upper reactor hood 4 passing, gas outlet line 20 the reactor 1 leaves.

A constant radial exit velocity from the central tube 13 in the reaction space 7 is achieved by a careful design and mutual coordination of all pressure loss generating flow sections. The relevant design variables here are the ratio of the flow cross section of the central tube 13 to the total flow area of the central tube wall, the axial porosity distribution of the central tube wall and the pressure loss coefficients of the catalyst bed 8th and the gas-permeable outer wall 10 of the reaction space available. During operation, the catalyst bed is always settling 8th to count. To avoid bypass flows in the upper area of the catalyst bed 8th has the central tube 13 above a gas-impermeable area 21 , as well has the outer wall 10 above a gas-impermeable area 22 , In addition, the catalyst is in a sufficient amount in the reactor 1 filled so that the level of the catalyst is not below the impermeable area 21 of the central tube 13 and not under the impermeable area 22 the outer wall 10 decreases.

The reaction temperature in the catalyst bed 8th is made by a variety of with heat transfer 25 flowed through heat exchange tubes 9 controlled. The heat exchange tubes 9 are doing at their ends in an upper tube sheet 23 or in a lower tube sheet 24 brought in and sealed there with these sealed. Here, the heat exchange tubes 9 flowing heat transfer medium 25 via a heat carrier supply line 26 in the heat transfer manifold 28 directed. The distributor hood 27 is close to the bottom tube bottom 24 connected. Before entering the heat exchange tubes 9 becomes the heat carrier 25 within the distributor 28 with a homogenizer 29 , here designed as a perforated plate, evenly distributed over the flow cross-section. After flowing through the heat exchange tubes 9 the heat transfer medium arrives 25 in a heat carrier collector 30 , This is identical or similar to the heat transfer manifold 28 , The collector 30 has accordingly a collector hood 31 , Through a heat transfer line 32 becomes the heat carrier 25 from the reactor 1 led out and fed to a cooling device, not shown here. For maintenance and repair work is the collector 30 through a collector manhole 33 accessible. Access to the interior of the reactor 1 For example, by a detachable connection 34 in the gas outlet pipe 20 or by a manhole not shown here in the upper reactor hood 4 , Different thermal expansions of reactor jacket 3 and all located in the reactor interior elements of the heat exchange system of compensators 35 taken here as outside the upper reactor hood 4 arranged corrugated pipe compensators are formed.

The in the catalyst bed 8th located heat exchange tubes 9 are according to the invention in groups 36 (S. 2 ) arranged as far as possible parallel to the central axis. For the production and transport of the tube bundle, the heat exchange tubes 9 through several horizontal grids 37 fixed in position.

2 shows a cross section of the reactor showing the distribution of the heat exchange tubes 9 within the catalyst bed 8th , The heat exchange tubes 9 are to groups of full rows 38 and of intermediate rows 39 grouped, the radial flow channels 40 form. Reaches the radial extent of the intermediate rows 39 not to the extreme extent of the full rows 38 , this results in radial flow channels 40 with enlarged flow cross-section. Thus, if necessary, radial flow channels with reduced cooling surface density 41 be created. Furthermore, radially outside the heat exchange tube regions catalyst zones without cooling, ie adiabatic reaction zones 42 , intended. These adiabatic reaction zones can be arranged both radially inwards, ie towards the reactor axis, and also radially outwards, ie away from the reactor axis.

The two 3a and 3b show alternative embodiments of the series of heat exchange tubes 9 , In 3a These are arranged with their axes on straight lines, with heat exchange tubes 9 alternate in diameter.

3b shows a serpentine arrangement of the axes of the heat exchange tubes 9 thus forming a serpentine radial flow channel 40 form.

In 4 is a holding grid 37 for the (in the 4 not shown) heat exchange tubes shown. This consists essentially of radial retaining elements 43 and of circular retaining elements 44 , The holding grid 37 can also by additional cross struts 45 be strengthened. The holding elements 43 . 44 . 45 are preferably made of rectangular semi-finished products. You still have preferred rounded upper and Bottoms to fill the reaction space 7 (Sat. 1 ) with catalyst does not hinder the fall of the same and to avoid dead spaces. The radial holding elements 43 hold the rows of heat exchange tubes 9 (Sat. 1 ) on both sides, wherein the flat bars are adaptable, for example, by changes in thickness to different pipe diameters. They thus fix the heat exchange tubes 9 a row to each other. The circular retaining elements 44 In turn, fix the various rows of tubes to each other by this with the radial holding elements 43 are connected.

The 5a shows a sectional view of the arrangement of bent heat exchange tubes 9 in a tube sheet 23 in the flight of two rows of pipes. Here are the tubes 9:01 . 9:02 and 9:03 in a row directly next to each other. The pipe 9:01 is doubly bent in two opposite directions to the right and penetrates the tubesheet 23 in a position offset to the right of the straight line arrangement. The pipe 9:02 is going straight through the tubesheet 23 guided. The pipe behind it 9:03 becomes analogous to the pipe 9:01 also doubly cranked, but to the left and left offset by the tubesheet 23 guided. With the row of pipes next to it with the pipes 9.11 . 9.12 and 9.13 is exactly the procedure.

The 5b shows a plan view of the tubesheet with the in 5a described from above visible pipe ends. The dashed circles indicate the location of the under the tubesheet 23 located cranked pipes.

At the in 6 illustrated embodiment, the catalyst space extends 49 or the catalyst bed filled in it 8th in the horizontal direction over the entire cross-section within the reactor shell 3 ie the horizontal cross-section through the catalyst bed 8th is a circular area whose edge is the inner wall of the reactor shell 3 forms. Accordingly, the heat exchange tubes 9 in the catalyst bed 8th also distributed on a circular area, ie a horizontal cross section through the bundle of heat exchange tubes 9 essentially also occupies a circular area. Here are the radially innermost heat exchange tubes 9 approximately circular around the reactor axis 6 arranged and the radially outermost heat exchange tubes 9 approximately circular with a predetermined distance to the inner wall of the reactor shell 3 arranged.

The terms "substantially" and "approximately" are intended to indicate that the radially innermost and outermost heat exchange tubes 9 Due to the design, they may not lie exactly on a circular line, but are displaced radially by a maximum of two pipe pitches.

The catalyst bed 8th lies on the outsides of the heat exchange tubes 9 and is in the operating state of the reactor 1 of reaction gas 15 flows through.

In this embodiment, reaction gas flow 15 and heat transfer medium 25 in the catalyst bed 8th in countercurrent, the reaction gas 15 from top to bottom and the heat transfer medium 25 from the bottom up.

That in the reactor 1 entering gas is called feed gas 16 denotes the catalyst bed 8th flowing, reacting gas as the reaction gas 15 and that from the reactor 1 escaping gas as product gas 19 ,

The feed gas 16 is in this embodiment by a gas inlet line 17 in the upper reactor hood 4 initiated and the product gas 19 through a gas outlet pipe 20 from the lower reactor hood 5 derived.

The lower ends of the heat exchange tubes 9 are in through holes of a lower tube plate 24 tightly welded and discharge into a heat transfer manifold 28 whose bottom is the bottom tube sheet 24 forms.

The upper ends of the heat exchange tubes 9 are in through holes of an upper tube plate 23 tightly welded and discharge into a heat transfer collector 30 whose bottom is the upper tube sheet 23 forms.

The lower reactor hood 5 spans the heat carrier distributor 28 and the upper reactor hood 4 the heat carrier collector 30 ,

In one embodiment, not shown, the heat transfer manifold 28 and / or the heat transfer collector 30 also be executed in several parts.

In the illustrated embodiment are heat transfer manifolds 28 and heat transfer collectors 30 ring-shaped, wherein the reactor axis 6 each passes through the ring center. The inner diameter of the rings is chosen so that the radially innermost heat exchange tubes 9 straight line between heat transfer manifold 28 and heat transfer collectors 30 can run. The outer diameter of the rings is smaller than the outer diameter of the bundle of heat exchange tubes 9 , so that radially further outward heat exchange tubes 9 have cranked pipe ends to enter the heat transfer manifold 28 or collector 30 to be able to lead. Halfway between the heat transfer manifold 28 and heat transfer collectors 30 go through the heat exchange tubes 9 a horizontal grid 37 . that the heat exchange tubes 9 stabilized in the horizontal direction.

In an embodiment not shown here, a plurality of holding grids 37 be arranged in the vertical direction.

The heat carrier distributor 28 is at least one heat carrier supply line 26 connected. In the illustrated embodiment, there are two heat carrier supply lines 26 coming from outside the reactor 1 vertically through the lower reactor hood 5 run.

The heat carrier collector 30 is at least one heat transfer line 32 connected. In the illustrated embodiment, there are two heat carrier drain lines 32 passing horizontally through the reactor jacket 3 run outwards.

The catalyst bed 8th extends in the vertical direction exclusively over the area in which all heat exchange tubes 9 have straight sections, ie not into the areas in which the radially outer heat exchanger tubes 9 are cranked.

Under the catalyst bed 8th is a bed of inert material - hereinafter also referred to as lower inert bed 14a designated - which is the lower part of the reactor 1 ie the lower reactor hood 5 and the lower part of the reactor shell 3 , to the beginning of the straight heat exchange tube sections in the bent heat exchange tubes 9 and thus until the beginning of the catalyst bed 8th fills. The top of the inert bed 14a therefore forms a catalyst support for vertical support of the catalyst bed 8th and thus to their limitation down.

The upper limit of the catalyst space 49 and thus the desired height of the catalyst bed 8th , ie the top, is located at a predetermined distance to the bottom of the upper tube sheet 23 or the heat transfer medium collector 30 , The space formed by this distance becomes dead space 50 designated.

The filling device 51 is above the catalyst space 49 arranged and has a catalyst distributor 52 and a variety of filling tubes 48 / 53 on.

The catalyst distributor 52 is annular and in the reactor 1 above the heat carrier collector 30 arranged. The cross section of the catalyst distributor 52 is trough-shaped with a bottom 54 and walls 55 going to the ground 54 tapering towards each other.

The filling pipes 48 / 53 are with their upper ends tight in through holes 56 (S. 8a ) in the ground 54 the catalyst distributor 52 fastened and open in these, see detailed representation in 8a , They run from the catalyst distributor 52 out initially bundle-shaped outward towards the reactor jacket 3 and then between the outer edge of the heat transfer medium collector 30 and the inner wall of the reactor shell 3 down into the dead space 50 into it. There they branch off and run in different directions and with different lengths in the spaces between the heat exchange tubes 9 , Wherein the entirety of the lower tube ends of the filling tubes 48 / 53 substantially uniform over the entire cross section of the catalyst space 49 is distributed. The filling pipes 48 / 53 have a minimum inclination over their entire length, which is a perfect flow or trickling of the catalyst material in the filling tubes 48 / 53 guaranteed.

In one embodiment, not shown, filling tubes 48 / 53 in multi-part heat transfer manifolds 28 and / or collectors 30 between two heat transfer manifolds 28 or collectors 30 be passed. It is also possible to fill pipes 48 by heat transfer manifold 28 or collector 30 pass therethrough.

The inner dimensions of the filling tubes 48 / 53 are designed so that only a given amount of catalyst material per unit time each filling tube 48 / 53 can go through, ie that results in a given trickle speed.

The filling device 51 remains permanently in the reactor 1 , Therefore, the heat transfer manifolds 28 and / or collectors 30 be designed freer, for example, with regard to easier accessibility to the heat exchange tubes 9 and regardless of an expansion option.

The upper reactor hood 4 has a catalyst filler neck 57 through, through it by means of a suitable device, the catalyst manifold 52 can be filled with catalyst material.

The lower reactor hood 5 has a catalyst discharge nozzle 58 through, through which the lower inert bed 14a , the catalyst bed 8th and possibly the upper inert bed 14b from the reactor 1 can be removed again.

Further, in the upper reactor hood 4 another manhole 59 trained, through which a fitter for maintenance and repair work in the upper area, ie above the heat transfer medium collector 30 , can get on. This manhole 59 can also be used to supply the catalyst.

In addition, the heat carrier supply line 26 and / or the heat carrier drain line 32 be designed so that through them access into the reactor interior is possible.

Unless otherwise described below, the embodiment corresponds to 7 the embodiment according to 6 ,

At the in 7 illustrated embodiment of a reactor according to the invention 1 is the catalyst space 49 or the catalyst bed 8th annular with a catalyst-free inner cavity 11 and a catalyst-free outer cavity 12 along the inner wall of the reactor shell 3 educated. On its radially outer side is the catalyst bed 8th from a cylindrical gas-permeable outer wall 10 enclosed. To avoid bypass flows, the gas-permeable outer wall closes 10 an impermeable area 22 at. Between the outer wall 10 and the inner wall of the reactor shell 3 is the outer cavity 12 educated. At its radially inner side is the catalyst bed 8th on a gas-permeable central tube 13 on or is limited by this, the axis of which on the reactor axis 6 lies.

According to the annular formation of the catalyst bed 8th is also the bundle of heat exchange tubes 9 ring-shaped. Here are the radially innermost heat exchange tubes 9 at a predetermined distance from the radially inner boundary of the catalyst bed 8th and the radially outermost heat exchange tubes 9 at a predetermined distance to the radially outer boundary of the catalyst bed 8th arranged.

In this embodiment, the gas flows from bottom to top, using it as feed gas 16 in the lower end of the gas inlet line 17 is initiated and in the catalyst bed 8th through the gas-permeable wall of the central tube 13 in the catalyst bed 8th flows in, this substantially radially as a reaction gas 15 flows through and then in the outer cavity 12 vertically upwards to a gas outlet pipe 20 flows and out of this as product gas 19 exit.

As the heat carrier 25 also flows from bottom to top, in this embodiment, a direct current of heat transfer 25 and gas available.

All heat exchange tubes 9 run in this embodiment in a straight line over its entire length. As in the embodiment according to 6 are the lower ends of the heat exchange tubes 9 in through holes of a lower tube plate 24 tightly fastened and open into a heat transfer manifold 28 whose bottom is the bottom tube sheet 24 forms. Furthermore, the heat carrier distributor 28 a distributor hood 27 on top of the lower tubesheet 24 spanned and tightly connected to this.

The upper ends of the heat exchange tubes 9 are in through holes of an upper tube plate 23 tightly fastened and open into a heat transfer collector 30 whose bottom is the upper tube sheet 23 forms and further a dome-shaped in this embodiment collector hood 31 which has the upper tube sheet 23 spanned and tightly connected to this.

In the collector's hood 31 is a collector manhole 33 designed to provide an installer for maintenance and repair access to the heat exchange tubes 9 to enable.

The heat carrier distributor 28 and the heat carrier collector 30 are annular, each having a central passage opening, which is the central tube 13 in the case of the heat transfer manifold 28 passes through and into the central tube 13 in the case of the heat transfer medium collector 30 extends for a given distance.

The radially outer edge of heat transfer manifold 28 and heat transfer collectors 30 lies between the radially outer heat exchanger tubes 9 and the radially outer boundary of the catalyst bed 8th , so that between the radially outer edge of the heat transfer manifold 28 (and also of the heat carrier collector 30 ) and the inner wall of the reactor shell 3 an annular gap is formed whose radial extent is greater than that of the outer cavity 12 ,

The heat carrier distributor 28 is at least one heat carrier supply line 26 connected. In 7 are two heat carrier supply lines 26 shown running vertically and through the lower reactor hood 5 extend to the outside.

The heat carrier collector 30 is at least one heat transfer line 32 connected. In 7 are two heat carrier drain lines 32 shown vertically through the upper reactor hood 4 through to the outside and in turn to an outer, annular heat transfer medium collector 60 are connected. The outer heat carrier collector 60 is in turn to a horizontal heat carrier drain line 61 connected.

The vertical heat carrier drain lines 32 between the one in the upper reactor hood 4 located heat carrier collector 30 and the outer heat carrier collector 60 point inside the upper reactor hood 4 one compensator each 35 to compensate for different thermal expansions.

Halfway between the lower and upper tubesheet 24 and 23 or between heat transfer manifold 28 and heat transfer collectors 30 is for horizontal stabilization of the heat exchange tubes 9 a horizontal grid 37 arranged, which is the heat exchange tubes 9 run through.

The central tube 13 extends down through the lower reactor hood 5 through and beyond this outwards and forms a gas inlet line 17 for the feed gas 16 , From the lower end, ie from the inlet opening for the feed gas 16 , until the lower beginning of the catalyst bed 8th is the wall of the central tube 13 gas impermeable trained.

At its upper end, the central tube extends 13 into the central opening of the annular heat transfer medium collector 30 , In its upper end area is the central tube 13 also with a gas-impermeable wall 21 formed, extending from the top of the central tube 13 up to a predetermined distance in the catalyst bed 8th extends into it. The upper end of the central tube 13 is gas-tight.

The lower part of the reactor 1 - ie the lower reactor hood 5 and the lower part of the reactor shell 3 to the lower end of the catalyst bed 8th - is also here with a lower inert bed 14a filled. The top of this lower inert bed 14a thus forms the lower boundary and vertical support for the catalyst bed 8th ,

At the in 7 illustrated embodiment, the catalyst manifold extends 52 the filling device 51 annular along the inside of the reactor shell 3 over its entire circumference. He is above the gap or annular gap between the outside of the heat transfer medium collector 30 and the inner wall of the reactor shell 3 arranged so that the filling tubes 53 from the ground 54 the catalyst distributor 52 from to below the upper tube bottom 23 or the heat transfer medium collector 30 extend vertically and then as in the embodiment according to 6 in the form of an ostrich in the bundle of heat exchange tubes 9 branch into it.

In 7 is the state after complete filling of the catalyst space 49 represented with catalyst material, ie the top of the catalyst bed 8th lies at the lower tube ends of the filling tubes 53 at. The filling pipes 53 and the catalyst manifold 52 are still filled with catalyst material, so that when setting the catalyst bed 8th Even during reactor operation, catalyst material automatically into the catalyst space 49 is refilled. In this embodiment, there is still an upper inert bed 14b over the catalyst bed 8th ,

The upper reactor hood 4 has as in the embodiment according to 6 a catalyst filler neck 57 and a manhole 59 on.

Likewise, the lower reactor hood 5 as in the embodiment according to 6 a catalyst discharge nozzle 58 on.

The in 7 represented reactor 1 also has a fluidizing device 62 for emptying the reactor 1 on. They include distribution lines 63 for a fluidizing gas between the catalyst bed 8th and the heat transfer manifold 28 in the lower inert bed 14a run. The distribution lines 63 have a loop 64 on top of that bunch of heat exchange tubes 9 runs around and to a gas supply line 65 connected horizontally through the reactor jacket 3 extends outwards and outside the reactor shell 3 a compressor 66 having. The gas can be supplied in a dehumidified state at elevated pressure and pulsating continuously or with pressure surges. Furthermore, the distribution lines 63 still radial branches 67 on that with the loop 64 fluidly connected and within the lower inert bed 14a into the bundle of heat exchange tubes 9 extend into and out of which the fluidizing gas exits. Optionally, there are further, preferably separately operable, lower branch lines 68 , which are below the bundle of heat exchange tubes 9 are arranged.

In 8a is on an enlarged scale the connection of the upper pipe end of a filling tube 53 to the ground 54 the catalyst distributor 52 shown. The upper tube end of the filling tube 53 has a radially expanded shoulder portion 69 on that with the ground 54 the catalyst distributor 52 is tightly connected. The floor 54 indicates a slope to the mouth of the filling tube 53 so that catalyst material from the side areas of the catalyst manifold 52 slides towards the junction. In the shoulder section 69 at the upper tube end of the filling tube 53 is a throttle 70 with a throttle opening 71 arranged, by means of the per unit time in the filling tube 53 entering amount of catalyst material and thus the rate of trickling out of the filling tube 53 exiting catalyst material is set.

The filling tube 53 has an oval cross section ( 8b ). The smaller cross-sectional dimension 72 is due to the size of the gap between adjacent heat exchange tubes 9 , by through the filling tube 53 runs, determined. The size of the larger cross-sectional dimension 73 is set so that the free passage cross section 74 of the filling tube 53 is sufficiently large compared to the dimensions of the catalyst particles, to jamming of catalyst particles and thus clogging of the filling tubes 53 to avoid.

LIST OF REFERENCE NUMBERS

1

 reactor

2

 pressure shroud

3

 reactor shell

4

 Upper reactor hood

5

 Lower reactor hood

6

 Central axis / reactor axis

7

 reaction chamber

8th

 catalyst bed

9

 Heat exchange tubes

10

 Outer wall of the reaction space

11

 Inner cavity

12

 Outer cavity

13

 Central tube / inner wall of the reaction space

14a

 Lower inert bed

14b

 Upper inert bed

15

 reaction gas

16

 feed gas

17

 Gas inlet pipe

18

 Openings in the central tube

19

 product gas

20

 Gas discharge line

21

 Impermeable area in the central tube

22

 Impermeable area in the outer wall of the reaction space

23

 Upper tube sheet

24

 Lower tube sheet

25

 heat transfer

26

 Heat transfer supply line

27

 distribution hood

28

 Heat transfer manifold

29

 The equalizing device

30

 Heat carrier collector

31

 collectors hood

32

 Heat carrier drain pipe

33

 Collectors manhole

34

 Detachable connection

35

 compensator

36

 Group of heat exchange tubes

37

 holding grid

38

 full series

39

 between rows

40

 Radial flow channel

41

 Radial flow channel with reduced cooling surface density

42

 Adiabatic reaction zone

43

 Radial retaining elements

44

 Circular holding elements

45

 crossbars

48

Fill pipes through the heat carrier collector

49

catalyst chamber

50

dead space

51

 filling

52

catalyst distribution

53

filling tubes

54

Bottom of the catalyst distributor

55

Walls of the catalyst distributor

56

Through holes

57

Katalysatorfüllstutzen

58

Catalyst drain nozzle

59

manhole

60

Annular heat carrier collector

61

Horizontal heat carrier drain line

62

fluidisation

63

distribution lines

64

loop

65

Gas supply line

66

compressor

67

branch lines

68

Lower branches

69

 shoulder portion

70

throttle

71

 throttle opening

72

 Smaller cross-sectional dimension

73

Larger cross-sectional dimension

74

Passage section

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 2165755 A1 [0004]
• DE 10031347 A1 [0005]
• EP 2363203 A1 [0006]
• DE 102009031765 A1 [0007]
• DE 202007006812 U1 [0035]

Claims (19)

Radially flowed reactor ( 1 ) for carrying out chemical-catalytic reactions with an isothermal reaction regime, comprising one essentially around a central axis ( 6 ) arranged cylindrical jacket ( 3 ), within which a substantially annular reaction space ( 7 ), which has a perforated central tube ( 13 ) and from an outer cavity ( 12 ) is enclosed, wherein the outer cavity ( 12 ) and the reaction space ( 7 ) through a perforated outer wall ( 10 ) and outer cavity ( 12 ) and central tube ( 13 ) for supplying the reaction gas ( 15 ) and for the removal of the product gas ( 19 ), characterized in that the reaction space ( 7 ) of a plurality of heat exchange tubes ( 9 ) is penetrated, wherein the heat exchange tubes ( 9 ) as far as possible parallel to the central axis ( 6 ) and are arranged in several groups, so that the groups full rows ( 38 ), which in the reaction space ( 7 ) are arranged in the radial direction, wherein the outer contours of adjacent heat exchange tubes ( 9 ) of a series ( 38 . 39 ) are so close to each other that radial flow channels ( 40 ) are formed. Reactor ( 1 ) according to claim 1, characterized in that at least one heat exchange tube ( 9 ) a group on at least one pipe end single or preferably double cranked and at least one side in a tube sheet ( 23 . 24 ) is attached. Reactor ( 1 ) according to one of the preceding claims, characterized in that between the full rows ( 38 ) of heat exchange tubes ( 9 ) other groups of heat exchange tubes ( 9 ), the shorter intermediate rows ( 39 ) form. Reactor ( 1 ) according to one of the preceding claims, characterized in that between the perforated central tube ( 13 ) and the full rows ( 38 ) of the heat exchange tubes ( 9 ) and / or between the perforated outer wall ( 10 ) and the full rows ( 38 ) of the heat exchange tubes ( 9 ) in annular spaces adiabatic reaction zones ( 42 ) and / or the full or intermediate rows of at least one annular adiabatic intermediate zone are interrupted. Reactor ( 1 ) according to one of the preceding claims, characterized in that the heat exchange tubes ( 9 ) have a continuous circular cross section or at their ends have a circular and in the central region an elongated cross section. Reactor ( 1 ) according to one of the preceding claims, characterized in that the heat exchange tubes ( 9 ) have varying cross-sections within a group. Reactor ( 1 ) according to one of the preceding claims, characterized in that the distance between the outer contours of adjacent full rows ( 38 ) or adjacent full and interim series ( 39 ) from the central tube ( 13 ) increases to the outside or remains largely the same. Reactor ( 1 ) according to one of the preceding claims, characterized in that the axes of the heat exchange tubes ( 9 ) lie at least one full or intermediate row on a radially outwardly directed straight line. Reactor ( 1 ) according to one of claims 1 to 7, characterized in that the axes of the heat exchange tubes ( 9 ) form a serpentine line at least one full or intermediate row. Reactor ( 1 ) according to one of the preceding claims, characterized in that at least one end, preferably at both ends, of the heat exchange tubes ( 9 ) a distributor ( 28 ) or collectors ( 30 ) for heat transfer ( 25 ) is arranged. Reactor ( 1 ) according to claim 10, characterized in that the heat carrier supply line ( 26 ) and / or the heat transfer ( 32 ) via compensators ( 35 ) with the reactor jacket ( 3 ) or the upper ( 4 ) or lower reactor hood ( 5 ) are connected. Reactor ( 1 ) according to one of the preceding claims, characterized in that the perforation of the central tube ( 13 ) and / or the outer wall ( 10 ) of the reaction space ( 7 ) in the axial direction of the reactor ( 1 ) varies. Reactor ( 1 ) according to one of the preceding claims, characterized in that between the heat exchange tubes ( 9 ) in the reaction space ( 7 ) a catalyst ( 8th ) is filled in the form of a granular bed and the ratio of the heat exchange surface of the heat exchange tubes ( 9 ) to the catalyst volume in the radial flow direction decreases or remains constant and behaves as 10 m ² / m ³ to 200 m ² / m ³ , preferably as 50 m ² / m ³ to 110 m ² / m ³ . Reactor ( 1 ) according to claim 13, characterized in that the catalyst to be filled ( 8th ) has a particle size between 1 mm to 2 mm in diameter and 3 to 15 mm in length, preferably between 3 mm and 6 mm in length, or particularly preferably spherical particles having a diameter of 1 mm to 3 mm, preferably 1.5 to 2 mm. Reactor ( 1 ) according to one of the preceding claims, characterized in that in the reactor ( 1 ) a filling device ( 51 ) for filling the reaction space ( 7 ) with catalyst bed ( 8th ) above the reaction space ( 7 ), which comprises: at least one catalyst distributor ( 52 ) outside the bundle of heat exchange tubes ( 9 ) is arranged, and a plurality of filling tubes ( 53 ), with their upper tube ends in each case in the at least one catalyst distributor ( 52 ) flow into one through the uppermost region of the reaction space ( 7 ) formed dead space ( 50 ) extend into it and open with their lower tube ends in this, wherein in the dead space ( 50 ) the course of all filling tubes ( 53 ) is coordinated so that the entirety of its lower tube ends over the entire cross section of the catalyst space ( 49 ) is distributed. Use of a reactor according to one of the preceding claims with largely directly juxtaposed heat exchange tubes forming radial flow channels, and with molten salt as heat transfer in the heat exchange tubes to achieve an approximately isothermal reaction regime. Use of a reactor according to any one of claims 1 to 15 for carrying out a reaction with heat of reaction with approximately isothermal reaction regime with molten salt as a heat carrier within the heat exchange tubes. Use of a reactor according to one of claims 1 to 15 for gas-phase reactions, preferably exothermic or endothermic catalytic reactions. Use of a reactor according to any one of claims 1 to 15 for oxidation, hydrogenation, dehydrogenation, nitration, alkylation or for the production of hydrocarbons from alcohols or dimethyl ether, in particular for gasoline synthesis from methanol and synthesis of methanol from synthesis gas.

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