Multi-stage liquid distributor for a separation device including a dual trough pre-distributor

Abstract

A liquid distributor for a separation apparatus such as a mass transfer column, particularly a packed column for absorption, stripping, scrubbing or distillation, or for a reactor, such as for distributing liquid above a catalyst bed of the reactor, comprising at least one pre-distributor element and a plurality of distributor elements, wherein the at least one pre-distributor element is disposed above the plurality of distributor elements, the at least one pre-distributor element comprising at least two troughs each comprising a plurality of discharge openings, each two of the at least two troughs being connected to one another, and a first trough of the at least two troughs being connected to an overflow trough. The system comprises a row means and an overflow means or at least one deflector attached to a side wall of a first of the at least two troughs, wherein a second of the at least two troughs has an upper edge, and the overflow means or at least one deflector attached to the side wall of the first trough extends from above the upper edge of the second trough to the second trough, so that when the liquid level in the first trough reaches the overflow means, liquid flows from the first trough over the overflow means and the at least one deflector into the second trough.

Description

[Technical Field]

[0001] The present invention relates to a liquid distributor for a separation apparatus such as for a mass transfer column, in particular for a packed column for absorption, stripping, scrubbing or distillation, or for a reactor, such as for distributing liquid above a catalyst bed of a reactor, comprising at least one pre-distributor element and a plurality of distributor elements, a separation apparatus comprising such a liquid distributor, and a method for using the same.

[0002] Separation devices such as mass transfer columns are used for intensive gas-liquid or liquid-liquid contact in a wide variety of processes, particularly absorption, stripping, scrubbing, distillation, and extraction. Distillation columns are designed, for example, to separate a specific substance from a liquid mixture containing two or more substances by selective evaporation and condensation. For this purpose, distillation columns contain a boiler at the bottom and a condenser at the top, so that during operation, vapor rises and liquid descends, allowing gas-liquid contact for mass transfer between the two phases. Substances with higher boiling points are concentrated in the liquid phase, while substances with lower boiling points are concentrated in the gas phase. To achieve intensive gas-liquid contact, such columns are typically filled with internals to optimize gas-liquid mass transfer. Examples of such internals are trays and packings, such as random packings and structured packings, especially those with a cross-channel structure. An essential requirement for optimal mass transfer between both phases is that the liquid be uniformly distributed across the cross section of the trays or packing, respectively. Furthermore, especially in packed columns, i.e., columns containing random or structured packing, it is even more important that the liquid flow as a thin film over the surface of the packing to maximize the contact area and contact time between the liquid and gas phases. For both of these purposes, a liquid distributor is usually provided above the packing or in each packing layer, respectively. Such liquid distributors are also used in certain reactors, such as to distribute liquid above the catalyst bed of the reactor.

[0003] A liquid distributor typically includes one or more pre-distributor elements and multiple distributor elements arranged below the one or more pre-distributor elements. The pre-distributor element is also referred to as a parting box in the art. Typically, the pre-distributor element and the distributor element have the form of a trough including two side walls, two front walls, and one or more bottom walls. The upper surface of the trough opposite the one or more bottom walls may be closed by providing a top wall, or may be open. The troughs of the one or more pre-distributor elements each include multiple discharge openings in their bottom walls, and the troughs of the pre-distributor elements typically each include multiple discharge openings in their bottom walls, side walls, or both. The one or more pre-distributor elements are arranged parallel to each other in a plane, but the distributor elements are arranged parallel to each other in a plane below the longitudinal axis of the pre-distributor element, and the longitudinal axis of the distributor element is perpendicular to the longitudinal axis of the pre-distributor element. The one or more pre-distributor elements and distributor elements are arranged so that the discharge openings of the one or more pre-distributor elements are above the open or closed top surfaces of the distributor elements. The number of distributor elements is much greater than the number of pre-distributor elements, because each of the one or more pre-distributor elements distributes liquid to multiple distributor elements, typically several tens of distributor elements. More specifically, during operation of the liquid distributor, liquid flows through an inlet of the liquid distributor into the supply line of the one or more pre-distributor elements. The supply line may or may not separate into two or more additional lines, each of which leads to one or more pre-distributor elements, for example, via their open or closed top surfaces. Liquid supplied into the one or more pre-distributor elements via the supply line remains there for a certain residence time before being discharged into the distributor elements via the open or closed top surfaces through discharge openings located in the bottom walls of the one or more pre-distributor elements. When the top surfaces of the distributor elements are each closed by a top wall, the top wall includes respective openings that allow liquid to be discharged from the corresponding pre-distributor elements through the discharge openings into the distributor elements. Each distributor member distributes liquid through its discharge opening.The liquid may be discharged directly onto the surface of the packing or packing layer located immediately below the distributor element, or it may be deflected using a guide element before it falls onto the surface of the packing or packing layer, respectively. For example, each distributor element may distribute the liquid in the form of a jet through its discharge opening. To form a thin liquid film, one or more deflectors or so-called screens in the form of specifically shaped guide walls may be arranged in front of (or in front of) the discharge opening of the distributor element, with which the liquid jet impinges at a specific impact angle to at least substantially prevent the formation of small droplets at the impact site on the screen. Avoiding such splashing typically requires a small impact angle of the liquid with the screen. The liquid film formed on the screen surface flows down the screen surface to the bottom edge of the screen, forming a drip edge from which the liquid falls in the form of droplets onto the surface of the packing or packing layer located immediately below the drip edge of the screen. Also known are respective liquid distributors comprising two groups of distributor members, each distributor member of the first group being connected with a distributor member of the second group in such a way that liquid flows from each of the distributor members of the first group to the distributor members of the second group, from which the liquid is discharged through their discharge openings and deflected by a screen as described above.

[0004] The liquid distributor described above is particularly suitable for an operating range of 1 to 3, where the operating range is the quotient of the maximum liquid load divided by the minimum liquid load. This is due to the fact that a minimum liquid height is required in the pre-distributor element to ensure uniform distribution of liquid across the cross-section of the pre-distributor element, which limits the cross-sectional area of ​​the trough at low liquid flow rates. Furthermore, because the liquid height in the trough at a given cross-sectional area is proportional to the square of the liquid load, the maximum possible height of the pre-distributor element is limited by the dimensions of the manway through which the pre-distributor element must move during installation in a separation system, thereby limiting the possible upper liquid load within the pre-distributor element. To increase the operating range, the height of the pre-distributor element can be correspondingly increased. However, in that case, the pre-distributor element would become so heavy that it could no longer be manually moved through the manway of a separation system, such as a distillation column, before being installed therein. Furthermore, the dimensions, and especially the height, of such an enlarged pre-distributor element would be too large for the manway typically found in separation systems. Therefore, if a wider operating range is required, one or more pre-distributor elements of a liquid distributor may each be provided with a partition extending along the length of the pre-distributor element, thereby making each pre-distributor element a multi-stage or dual-chamber element. The partition allows liquid to flow over the partition from the first chamber of the pre-distributor element to the second chamber of the pre-distributor element when a certain liquid level is reached in the first chamber. For this purpose, the partition may have a height lower than the side walls of the pre-distributor element, thereby forming an overflow edge. Alternatively, the partition may include one or more slits, holes, or differently shaped openings in its upper portion that allow liquid to flow from the first chamber through the overflow opening to the second chamber of the pre-distributor element. This allows only one chamber to operate in the event of a low liquid load, while both chambers are operated or filled with liquid in the event of a high liquid load, thereby allowing the pre-distributor element to operate over a wide operating range of 1 to 10.In an alternative application, each of the aforementioned pre-distributor elements with a partition wall may be operated with two different liquids, with the first liquid being supplied exclusively to the first chamber of the pre-distributor element through the first inlet and the second liquid being supplied exclusively to the second chamber of the pre-distributor element through the second inlet. During operation, neither liquid is guaranteed to flow past the partition wall. However, such pre-distributor elements with a partition wall have several drawbacks. First, to ensure that liquid flows exclusively from the first chamber to the second chamber of the pre-distributor element through the overflow edge or overflow opening, respectively, over long operating times, the partition wall must be fixed in the groove of such a pre-distributor element by seal welding. However, seal welding results in a large welding thermal shock and requires special welding equipment. Second, because such pre-distributor elements must be moved through a manway during installation in a mass transfer column, their maximum width and height are limited, thereby limiting the upper end of their operating range. Third, such pre-distributor members, being single-piece troughs, have a very high weight which hinders their installation if they utilize the maximum possible dimensions allowed by the dimensions of the manway.

[0005] In view of this, the underlying object of the present invention is to provide a liquid distributor for a mass transfer column, in particular for a type of packed column comprising one or more pre-distributor elements and a plurality of distributor elements, wherein the one or more pre-distributor elements do not require a partition secured to the pre-distributor elements by seal welding, and nevertheless, the liquid distributor, in particular the one or more pre-distributor elements, can operate over a wide operating range, even over a wider operating range than known seal-welded multi-stage pre-distributor elements, and nevertheless, the one or more pre-distributor elements can be easily installed in larger dimensions than known multi-stage pre-distributor elements, even through a manway of typical size.

[0006] This object is met, according to the present patent application, by providing a liquid distributor for a separation apparatus such as for a mass transfer column, in particular a packed column for absorption, stripping, scrubbing or distillation, or for a reactor, such as for distributing liquid above a catalyst bed of a reactor, the liquid distributor comprising at least one pre-distributor element and a plurality of distributor elements, the at least one pre-distributor element being disposed above the plurality of distributor elements, the at least one pre-distributor element comprising at least two troughs each comprising a plurality of discharge openings, each two of the at least two troughs being connected to one another, and a first trough having an overflow means and at least one deflector attached to the overflow means or a side wall of a first of the at least two troughs, a second of the at least two troughs having an upper edge, and the overflow means or at least one deflector attached to the side wall of the first trough extending from above the upper edge of the second trough to the second trough, such that when the liquid level in the first trough reaches the overflow means, liquid flows from the first trough over the overflow means and the at least one deflector into the second trough.

[0007] In a liquid distributor, by replacing the known seal-welded multi-stage pre-distributor element, i.e., a trough with a partition wall fixed along the longitudinal axis of the trough to divide the trough into two halves (or chambers), the pre-distributor element can include at least two (separate) troughs connected to each other, for example, by their side walls, so that when the liquid level in the first trough reaches the overflow means, the liquid flows from the first trough over the overflow means and at least one deflector into the second trough, and the troughs no longer need to be provided with a partition wall fixed by seal welding.On the contrary, it is simply necessary to connect the troughs, for example, via their side walls, which can be easily achieved by screwing, riveting, clamping, or any other mechanical connection method, or by simple spot welding, resulting in no or almost no welding thermal shock and no or only simple welding equipment being required. This is due to the fact that the overflow means and at least one deflector connected thereto, which extends into the second trough, ensure that liquid flows completely from the first trough over the overflow means and at least one deflector into the second trough without loss, even if a small gap should exist between the troughs, because one deflector extends into the second trough and thus extends across any possible small gap. Furthermore, because the pre-distributor member includes two separate troughs that can be easily connected to each other, each of the two troughs can have the same dimensions as the entire prior art seal-welded multi-stage pre-distributor member. As a result, the pre-distributor member of the present invention can be more than twice as wide as the prior art seal-welded multi-stage pre-distributor member. This is due to the fact that two, three, four, or more troughs of the pre-distributor member of the present invention can be moved separately from each other through the manway of the separation device and then connected thereto. Due to the possibility of achieving higher widths, the pre-distributor element according to the invention may be designed for an even wider operating range and therefore may be operated at even higher liquid loads than known seal-welded multi-stage pre-distributor elements of the prior art.Furthermore, since the troughs of the pre-distributor element according to the present invention can be moved separately from each other via separate manways, they can be designed to have the same low weight for easy transportation, and by combining a sufficient number of troughs with each other, a single pre-distributor element can still cover the same high operating range. Therefore, the use of the pre-distributor element according to the present invention also improves installation flexibility.

[0008] According to the invention, in accordance with the feature that the at least one deflector attached to the overflow means or the side wall of the first trough extends from above the upper edge of the second trough to the second trough means, the at least one deflector extends at least along a direction from the overflow means towards the adjacent second deflector and terminates above the second trough above the upper surface of the second trough, or in the second trough above the upper surface of the second trough, or in the second trough below the upper surface of the second trough.

[0009] Furthermore, the feature "so that liquid flows from the first trough over the overflow means and at least one deflector" means that the overflow means and the deflector are arranged in a manner suitable for operating the liquid distributor so that "liquid flows from the first trough over the overflow means and at least one deflector." Therefore, this feature does not require that such flow be realized under any possible operating conditions, but it is sufficient that it is achievable using appropriate operating conditions. Preferably, the overflow means or at least one deflector attached to the side wall of the first trough extends from above the upper edge of the second trough to or above the second trough so that when the liquid level in the first trough reaches the overflow means, liquid flows from the first trough over the upper surface of the overflow means and the at least one deflector and into the second trough.

[0010] According to the present invention, at least one pre-distributor element of a liquid distributor includes at least two troughs, each including a plurality of discharge openings. Preferably, at least two troughs, more preferably all of the at least two troughs, each include two sidewalls. Preferably, two adjacent troughs of the pre-distributor element are in contact with each other and connected to each other via their sidewalls. Therefore, the sidewalls of two adjacent troughs that are in contact with each other and connected to each other are separate sidewalls that can be separated from each other. Preferably, at least the sidewalls of the contacting troughs, or more preferably all the sidewalls of the troughs, have at least substantially the same length and width, and the contacting troughs are arranged so that both sidewalls are in contact with each other over their entire area. Contacting means that they are close to each other, and does not exclude the presence of a small gap of a few micrometers or millimeters. If present, the gap is preferably between 1 μm and 50 mm, more preferably between 1 μm and 10 mm, and even more preferably between 1 μm and 5 mm, and the gap refers to the distance between the two sidewalls. As mentioned above, adjacent troughs may be connected to one another by screwing, riveting, clamping or any other mechanical connection method, or by simple spot welding.

[0011] In a further development of the inventive concept, it is proposed that the at least two troughs, more preferably all of the at least two troughs, each comprise a bottom wall, the bottom wall comprising a plurality of discharge openings. Furthermore, further discharge openings may be arranged in one or more of the side walls of the at least two troughs. Preferably, the bottom walls of at least the first and second troughs are flat and essentially aligned with each other, where essentially aligned with each other means that the bottom wall of the second trough is in the same plane as the bottom wall of the first trough or in a plane below or above the plane of the bottom wall of the first trough that is no more than 10%, preferably no more than 5%, of the height of the highest side wall of the first trough.

[0012] According to a further preferred embodiment of the present invention, at least one of the first trough and the second trough, preferably all of them, has the form of a hollow box having two interconnected side walls, two front walls, and a bottom wall, the bottom wall having a plurality of discharge openings. Since all walls are fluid-tightly connected to each other, liquid can only exit the trough through the plurality of discharge openings. It is further preferred that the bottom walls of two adjacent troughs are at least substantially aligned with each other. The upper surface of each trough opposite the bottom wall may be closed by an upper wall, which includes one or more openings for supplying liquid into the trough, or preferably is open. Adjacent troughs may have the same width or different widths.

[0013] The present invention is not particularly limited with respect to the cross-sectional shape of the troughs or hollow boxes, respectively. For example, the hollow boxes may have, independently of one another, square, rectangular, trapezoidal, oval, polygonal or irregular cross sections. However, particularly good results are obtained when each hollow box has a square or rectangular cross section.

[0014] Preferably, none of the troughs of the pre-distributor means are provided with internal partitions, in particular with seal-welded internal partitions.

[0015] The present invention is not particularly limited in terms of the form of the overflow means. For example, the overflow means may include one or more selected from the group consisting of an overflow edge, an overflow slit, an overflow hole, and any combination of two or more thereof.

[0016] According to a first particularly preferred embodiment of the present invention, the overflow means of the first trough of the pre-distributor element of the liquid distributor includes one or more overflow edges or consists of one or more overflow edges. This can be easily achieved by providing two side walls of the first trough, one of which is higher than the other, with the overflow edge being the upper edge of the lower side wall. Preferably, at least one deflector attached to the overflow edge or side wall of the first trough extends from the lower side wall of the first trough to the second trough at an angle greater than 0° and less than 90°, preferably between 30° and 60°. In this context, 0° corresponds to a plane passing through the lower side wall, and 90° corresponds to a plane perpendicular to the plane of the lower side wall. As a result, in this embodiment, the first trough is higher than the second trough.

[0017] In this embodiment, particularly good results are obtained when the overflow edge (i.e., preferably the upper edge of the lower side wall) is at a height corresponding to 50-95%, preferably 60-90%, more preferably 70-90% of the height of the upper side wall. Furthermore, in this embodiment, it is preferred that the upper edge of the side wall of the second trough that is connected to the side wall of the first trough that includes or forms the overflow edge has a height that is approximately the same as the overflow edge or less than 90-100% of the height of the overflow edge.

[0018] In a further development of the inventive idea, it is proposed that the first trough has a deflector attached to the overflow edge or side wall and extending over at least 50%, preferably at least 70%, more preferably at least 90%, even more preferably at least 95%, and most preferably 100% of the length of the overflow edge. This ensures a uniform flow of liquid over the entire width of the overflow edge from the first trough to the second trough. Depending on the width and angle of the at least one deflector attached to the overflow means or side wall extending from above the upper edge of the second trough to the second trough, the at least one deflector may terminate in or above the second trough above the upper surface of the second trough, within the upper surface of the second trough, or below the upper surface of the second trough.

[0019] According to an alternative variation of this embodiment, the overflow edge and at least one deflector are formed by bending one of both side walls of the first trough to form the overflow edge, and the deflector is integrally connected to the overflow edge and preferably extends from the side wall to the second trough at an angle greater than 0° and less than 90°, more preferably between 30° and 60°.

[0020] According to a second particularly preferred embodiment of the present invention, the overflow means of the first trough of the pre-distributor element of the liquid distributor includes one or more, preferably several, overflow slits. The overflow slit is preferably provided in the upper part of one of the side walls of the first trough, and at least one deflector is attached to the overflow means or side wall so that liquid flowing through the overflow slit flows over the upper surface of the at least one deflector. Preferably, the at least one deflector extends from the side wall of the first trough where the overflow slit is provided to the second trough at an angle greater than 0° and less than 90°, preferably between 30° and 60°. In this embodiment, both side walls of the first trough may have the same size or different sizes. For example, the side wall of the first trough containing the slit is lower than the other side wall.

[0021] In this embodiment, the overflow slit preferably extends substantially vertically downward from the upper edge of one of the side walls of the first trough (i.e., the longitudinal sides of the slit are oriented vertically), and preferably the slit extends vertically downward from the upper edge of one of the side walls by 5 to 100 mm, more preferably 20 to 60 mm. The upper end of the slit may be located at the upper edge of the side wall so that the slit is at the top and not surrounded by the side wall, or the upper end of the slit may be located below the upper edge of the side wall so that the slit is completely surrounded by the side wall.

[0022] In particular, if the upper end of the slit is located at the upper edge of the sidewall and the slit is at a top that is not surrounded by the sidewall, the first preferred embodiment of the overflow edge described above can be combined with the second preferred embodiment of the overflow slit. In other words, in this variant, the first trough includes the overflow slit and several overflow edges, i.e., portions of the upper edge of the sidewall where the overflow slit is located, interrupted by slits. If the liquid flow is sufficiently high, the liquid not only flows through the overflow slit but also over the overflow edge. The portion of the sidewall of the first trough that covers the overflow edge and overflow slit is the overflow means.

[0023] At least one deflector is attached to the overflow means of the first trough in this embodiment below the lowest point of all the overflow slits.

[0024] In a further development of the inventive concept, it is suggested that the first trough have a deflector attached to the overflow means or the side wall and extending over at least 50%, preferably at least 70%, more preferably at least 90%, even more preferably at least 95%, and most preferably 100% of the length of the side wall where the overflow slit of the first trough is provided. This ensures that liquid flows uniformly over the entire width of the overflow means from the first trough to the second trough. Depending on the width and angle of the at least one deflector attached to the overflow means or the side wall extending from above the upper edge of the second trough to the second trough, the at least one deflector may terminate in or above the second trough above the upper surface of the second trough, within the upper surface of the second trough, or below the upper surface of the second trough.

[0025] According to a third particularly preferred embodiment of the present invention, the overflow means of the first trough of the pre-distributor member of the liquid distributor comprises one or more, preferably several, overflow openings having another form than a slit, such as having a circular, elliptical or oval cross section. The preferred features mentioned above for the overflow slits of the second embodiment are also preferred for the overflow openings of the third embodiment.

[0026] Preferably, at least one deflector of a first trough of a pre-distributor means of a liquid distributor according to the invention extends from the overflow edge towards the adjacent second trough by 1 to 30%, preferably 5 to 20%, of the width of the second trough, the direction towards the adjacent second trough being the direction of a straight line extending vertically through all side walls of the first and second troughs.

[0027] Particularly good results are obtained if at least one deflector of a first trough extends 10 to 40 mm in a direction from the overflow means towards the adjacent second trough.

[0028] According to a further preferred embodiment of the present invention, at least one pre-distributor member of the liquid distributor comprises three troughs each comprising two side walls, the first trough and the second trough are in contact with each other and connected to each other by each of their side walls, the second trough and the third trough are in contact with each other and connected to each other by each of their side walls, each of the first trough and the second trough has an overflow means and at least one deflector attached to the overflow means or the side wall, each of the second trough and the third trough has an upper edge, and the overflow means or the at least one deflector attached to the side wall of the first trough has an upper edge and the at least one deflector attached to the side wall of the second trough has an upper edge. the at least one deflector attached to the overflow means of the second trough extends from above the upper edge of the trough to the third trough, so that when the liquid level in the first trough reaches the overflow means, liquid flows from the first trough over the overflow means (preferably over the upper surface of the overflow means) and over the at least one deflector into the second trough, and the at least one deflector attached to the overflow means of the second trough extends from above the upper edge of the second trough to the third trough, so that when the liquid level in the second trough reaches the overflow means, liquid flows from the second trough over the overflow edge through the at least one deflector into the third trough.

[0029] Each of the features described above for the overflow means and the at least one deflector of the first trough is also preferred for the overflow means and the at least one deflector of the second trough. In particular, it is preferred that each of the deflectors of the first trough and the second trough extend at an angle of greater than 0° and less than 90°, preferably between 30° and 60°, of the lower side wall of the respective trough.

[0030] Preferably, the first trough has a height greater than the second trough, and the second trough has a height greater than the third trough. The height of a trough refers to the length of a straight line extending from the lowest point to the highest point of the trough.

[0031] According to a further development of the inventive idea, the pre-distributor member, or in the case of two or more pre-distributor members, at least one, and more preferably all, of the pre-distributor members comprises four, five, six or even more troughs embodied in the same way as the first trough, second trough and third trough described above and connected to one another.

[0032] Depending on the diameter of the liquid distributor and the planned liquid load, the liquid distributor according to the present invention preferably comprises one to four pre-distributor elements. Preferably, each of these pre-distributor elements is designed as described above. If the liquid distributor comprises two or more pre-distributor elements, it is preferred that all of the pre-distributor elements are arranged at least substantially parallel to one another and in at least one plane. At least substantially parallel means that the longitudinal axes of adjacent troughs do not deviate from a parallel arrangement by more than 20°, preferably more than 10°, and more preferably more than 5°. In at least one plane, the bottom wall of a trough does not deviate from the plane spanned by the bottom wall of the first trough by more than 10% of the height of the first trough.

[0033] Furthermore, the distributor members are preferably arranged adjacent to each other in at least substantially one plane, defined relative to the distributor member in the same way as the pre-distributor member in at least substantially one plane.

[0034] The distributor elements may be configured and arranged relative to one another as known in the art. For example, the distributor elements may include a first group of distributor elements arranged at least substantially parallel to one another, the first group of distributor elements having the form of a hollow box with two interconnected side walls, two front walls, and a bottom wall, with one of the bottom and / or side walls having a plurality of discharge openings. The hollow box preferably has a square or rectangular cross section, but in principle may have a square, rectangular, trapezoidal, oval, polygonal, or irregular cross section. The top surfaces opposite the bottom wall may be open or may each be closed by a top wall. Preferably, each top surface of the distributor elements is arranged so that liquid flowing through the plurality of discharge openings of the at least two troughs of at least one front distributor element flows through the top surface to the distributor elements of the first group. In particular, good results are obtained when the bottom walls of the distributor elements of the first group are at least substantially aligned with one another. In particular, the bottom walls of the distributor members of the first group may be arranged such that their length axes are at least substantially perpendicular to the length axis of the previous distributor member.

[0035] If the liquid distributor includes only distributor elements of the first group, it is preferred that multiple discharge openings are provided in their side walls. However, they may also include multiple discharge openings in their bottom wall, or only in their bottom wall instead of the side walls. Preferably, the liquid distributor includes, for each distributor element, at least one screen arranged in front of the corresponding distributor element's discharge opening, so that the liquid jet flowing through each distributor element's discharge opening impinges on the surface of the at least one screen and is deformed thereon into a thin, flowing liquid film. In particular, if the liquid distributor is designed for a packed column, it is preferred that the at least one screen be arranged to shield the discharge opening from the upwardly flowing gas flow.

[0036] In a further development of the idea of ​​the present invention, it is proposed that at least one screen is arranged in front of the discharge openings in such a way that, in the case of maximum liquid outflow, the liquid jet emerging through the discharge openings of the distributor members of the second group impinges on the surface of the at least one screen at an angle of less than 60°, preferably less than 30°, more preferably less than 10°, the angle being the angle between the direction of the liquid jet emerging through the discharge opening and the tangent at the point on the surface of the screen where the liquid jet impinges.

[0037] Each of the at least one screen may have a sigmoidal curve shape in the vertical direction as well as in the jet-parallel cross section, the sigmoidal curve more preferably curving downwards and / or having a substantially constant curvature in the region where the liquid jet impinges on the surface of the at least one screen.

[0038] Preferably, the at least one screen is arranged in front of the discharge openings so that the liquid jets emerging through the discharge openings of the distributor member impinge essentially tangentially on the surface of the at least one screen.

[0039] According to an alternative embodiment of the present invention, the liquid distributor may include, in addition to the distributor members of the first group described above, distributor members of a second group having the form of a hollow box having two side walls, two front walls and one or two bottom walls connected to each other, wherein the bottom wall and / or one of the side walls has a plurality of discharge openings for the outflow of liquid in the form of jets, and the upper surface opposite the bottom wall is opened and closed by the upper wall, and the liquid flowing through the discharge openings of the distributor members of the first group flows into the distributor members of the second group through the upper surface and / or through the openings in the upper wall and / or through the openings in the side walls of the distributor members of the second group.

[0040] Preferably, the liquid distributor includes at least one screen arranged and designed as described above for each distributor member of the second group, more preferably for the embodiment, and the liquid distributor includes only distributor members of the first group.

[0041] According to yet another embodiment of the present invention, the liquid distributor may include distributor members instead of the first and second groups of distributor members described above, each of which is provided with a partition wall, thus separating the interior volume of the distributor member into a first chamber and a second chamber. The distribution chambers may be troughs as described above, i.e., troughs including two side walls, two front walls, and a bottom wall. The partition wall disposed therein is preferably not connected to a deflection means. Discharge openings are provided in the bottom and / or side walls of both chambers of each distributor member. A liquid distributor having at least one front distributor member according to the present invention and one or more of these distributor members is particularly suitable for use in a reactor for distributing one or more liquids above a catalyst bed. Such a liquid distributor is particularly suitable for use in distributing individual liquid phases to one or more catalyst beds of a reactor. For example, each of the two chambers of each distributor member is filled with a different liquid, and both liquids are distributed separately from each other onto the catalyst bed located below through the discharge openings of the respective chambers of each distributor member. For regeneration or cleaning of the distributor members, cleaning liquid may be supplied at an increased load to one of the chambers of the distributor members so that liquid overflows from the respective chamber of each distributor member into the adjacent chamber of each distributor member.

[0042] According to a further aspect, the present invention relates to a mass transfer column, in particular for absorption, stripping, scrubbing or distillation, comprising at least one packing and at least one liquid distributor as described above. Furthermore, the present invention relates to a reactor comprising one or more catalyst beds and at least one liquid distributor as described above for distributing liquid over the one or more catalyst beds.

[0043] Furthermore, the present invention relates to a method for separating at least two fluids, preferably for carrying out absorption, stripping, scrubbing or distillation, which method is carried out using at least one of the aforementioned columns.Furthermore, the present invention relates to a method for distributing liquids, preferably two different liquids, separately from one another above one or more catalyst beds in a reactor, which method is carried out using at least one of the aforementioned reactors.

[0044] According to another particularly preferred embodiment of the invention, the liquid distributor comprises only distributor members, which are as described above for the second group of distributor members.

[0045] Subsequently, the present patent application will be described by way of example with reference to advantageous embodiments and the accompanying drawings.

[0046] The following is shown: [Brief explanation of the drawings]

[0047] [Figure 1] 1 is a schematic longitudinal cross-sectional view of a mass transfer column including packing and a liquid distributor according to one embodiment of the present invention. [Figure 2] 1 is a schematic perspective view of a front distributor member of a liquid distributor according to the prior art; [Figure 3a] 1 is a schematic perspective view of a pre-distributor member of a liquid distributor according to one embodiment of the present invention; FIG. [Figure 3b] FIG. 3b is an enlarged cross-section of the pre-distributor member shown in FIG. 3a. [Figure 3c] 3b is a schematic perspective view of a liquid distributor including the pre-distributor member shown in FIG. 3a. [Figure 4] 10 is a schematic perspective view of a pre-distributor member of a liquid distributor according to another embodiment of the present invention. FIG. [Figure 5] 4 is a schematic cross-sectional view of a distributor member of a liquid distributor according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0048] The mass transfer column 10 shown in Figure 1 includes packing 12 and a liquid distributor 14. The liquid distributor 14 includes a pre-distributor member 16 and several distributor members 18. During operation of the mass transfer column 10, a gas 20 rises through the mass transfer column 10, passes around the distributor member 18, and is divided by the distributor member 18 into multiple partial gas streams 22', 22'. Liquid 24 is supplied to the liquid distributor 14 via a feed line 26, passes through the pre-distributor 16, and is directed to the distributor member 18, from where it is evenly distributed onto the packing 12 and falls.

[0049] The prior art pre-distributor member 17 of a liquid distributor shown in FIG. 2 comprises a trough 28, a partition wall 30 fixed to the trough 28 by seal welding, extending along the longitudinal axis of the trough 28, and dividing the trough 28 into two chambers, a first chamber 32 and a second chamber 32′. The partition wall 32 includes an overflow slit 34. When the liquid level reaches the lower end of the overflow slit 34 in one of the chambers 32, 32′ of the trough 28, the liquid flows over the overflow slit 34 into the other chamber 32, 32′ of the trough 28. This prior art seal-welded multi-stage pre-distributor member 17 has several drawbacks. First, to ensure that liquid flows from the first chamber 32 of the pre-distributor member 17 to the second chamber 32′ (or vice versa) only through the overflow slit 34 over a long operating time, the partition wall 30 must be fixed within the trough 28 of such a pre-distributor member 17 by seal welding. However, seal welding results in significant weld thermal shock and requires special welding equipment. Second, because such pre-distributor members 17 must be moved during installation into the mass transfer column 10 through the manway, they are limited in terms of their maximum width and height, which restricts the upper end of their operating range. Third, because such pre-distributor members 17 are single-piece troughs, they have a very high weight that prevents their installation if they utilize the maximum possible dimensions allowed by the manway dimensions.

[0050] To overcome these drawbacks, a liquid distributor according to one embodiment of the present invention, as shown in Figures 3a-3c, includes two troughs 36, 38: a first trough 36 and a second trough 38. Figures 3a and 3b schematically illustrate the liquid distributor 16, while Figure 3c illustrates a liquid distributor 14 including the pre-distributor member 16 and distributor member 18 shown in Figures 3a and 3b. Each of the troughs 36, 38 includes two side walls 40, 42, a bottom wall 44 including multiple discharge openings 46, and two front walls 48. The first trough 36 and the second trough 38 are connected to each other, for example, by riveting the second side wall 42 of the first trough 36 to the first side wall 40 of the second trough 38. The top surfaces 50 of both troughs 36, 38 are open. The second wall 42 of the first trough 36 is slightly lower than the first wall 40 and has several overflow slits 34. Furthermore, the upper edges 52 of the second wall 42 of the first trough 36, interrupted by the overflow slits 34, form several overflow edges 52. The portion of the side wall 42 containing the overflow edges 52 and the overflow slits 34 constitutes the overflow means 54 of the first trough 36. A deflector 56 connected to the overflow means 54 formed by the second wall 42 of the first trough 36 is positioned slightly below the lower ends of the overflow slits 34. The deflector 56 extends from the second side wall 42 of the first trough 36 to the second trough 38 at an angle greater than approximately 45°. The first and second side walls 42, 44 of the second trough 38, and therefore the upper edges 52' of the side walls, are lower than the upper edge of the first trough 36.

[0051] During operation, liquid flows from the supply line 26 into the first trough 36 of the pre-distributor member 16, as shown in FIG. 3c. A portion of the liquid flows through the discharge opening 46 of the first trough 36 of the pre-distributor member 16, as shown in FIGS. 3a and 3b, and into the trough of the distributor member 18, which is located below the pre-distributor member 16, as shown in FIG. 3c. If the liquid load is sufficiently high, the liquid level in the first trough reaches the lower end of the slit 34 and, if even higher, may reach the upper edge 52 or overflow edge 52 of the first trough 36, respectively. Another portion of the liquid then flows through the overflow slit 34 and, as the case may be, the upper edge 52 or overflow edge 52, respectively, from where it flows over the deflector 56 into the second trough 38. From there, the liquid flows through the discharge opening 46 of the second trough 38 of the pre-distributor element 16 and into the trough of the distributor element 18, which is arranged below the pre-distributor element, as shown in FIG. 3c. In order to avoid the need for a seal-welded bulkhead, as in the prior art and as shown in FIG. 2, the pre-distributor element 16 of the liquid distributor according to the invention is easy to manufacture, in particular with little or no welding thermal shock and without any or only simple welding equipment. This is due to the fact that, thanks to the overflow means 54 and the at least one deflector 56 connected thereto and extending into the second trough 38, one of the deflectors 56 extends into the second trough 38, thus overcoming any possible small gap, ensuring a reliable and complete flow of liquid from the first trough 36 over the overflow means 54 and the at least one deflector 56 into the second trough 38 without any loss of liquid, even if a small gap should exist between the two troughs 36, 38. Furthermore, because the pre-distributor member 16 includes two separate troughs 36, 38 that can be easily connected within the separation device, each of the troughs 36, 38 can have the same dimensions as the entire seal-welded multi-stage pre-distributor member 17 of the prior art, and as a result, the pre-distributor member 16 of the present invention can have a width that is more than twice as wide as the seal-welded multi-stage pre-distributor member 17 of the prior art.Due to the possibility of achieving a higher width, the pre-distributor member 16 according to the invention may be designed for an even wider operating range and therefore for even higher liquid loads than the known seal-welded multi-stage pre-distributor members 17 of the prior art. Furthermore, since the troughs 36, 38 of the pre-distributor member 16 according to the invention can be moved separately from one another through a separation manway, they can each be designed to have an equally low weight for easy transport, and by combining a sufficient number of troughs 36, 38 together into one pre-distributor member 16, an equally high operating range can nevertheless be covered.

[0052] The pre-distributor member shown schematically in Figure 4 is similar to that described above with respect to Figures 3a-3c, but includes three troughs 36, 38, 58. Each of the three troughs 36, 38, 58 includes two side walls 40, 42, the first trough 36 and the second trough 38 are in contact with each other and connected to each other by their respective side walls 40, 42, the second trough 38 and the third trough 58 are in contact with each other and connected to each other by their respective side walls 40, 42, and each of the first trough 36 and the second trough 38 has an overflow means 54 and at least one deflector 56 attached to the overflow means 54. The second trough 38 and the third trough 58 each have an upper edge 52, 52', and at least one deflector 56 attached to the overflow means 54 of the first trough 36 extends from above the upper edge of the second trough 38 to the second trough 38, so that when the liquid level in the first trough 36 reaches the overflow means 54, liquid flows from the first trough 36 over the overflow means 54 and the at least one deflector 56 into the second trough 38, and the at least one deflector 56 attached to the overflow means 54 of the second trough 38 extends from above the upper edge of the second trough 38 to the third trough 58, so that when the liquid level in the second trough 38 reaches the overflow means 54, liquid flows from the second trough 38 over the overflow means 54 and the at least one deflector 56 into the third trough 58.

[0053] FIG. 5 shows, in a schematic cross-sectional view, one of the distributor members 18 of a liquid distributor 14 according to another embodiment of the present invention. Each distributor member 18 thus has the form of a trough and is provided with a plurality of outlet openings 62 in the lower part of one of its side walls 60. A screen 64 is arranged in front of the outlet openings 62, so that the liquid jets emerging through the outlet openings 62 impinge on the surface of the screen 64 and are deformed thereon into a thin, flowing liquid film. The screen 64 has a cross-sectional form of a sigmoid curve, which curves downward and has a substantially constant curvature in the impingement region 66 where the liquid jets impinge on the surface of the screen 64. The screen 64 is fixed at its upper end 68 to the distributor member 18 and is designed at its lower end as a drip edge 70. The screen 64 further includes two skirts 72, 72′. While the first skirt 72 is fixed to the screen 64, the second skirt 72' is fixed to the liquid distributor 18. Both skirts 72, 72' advantageously allow the flow of the gas 20 to be influenced so that a stagnation zone 74 is formed below the distributor member 18 and the drip edge 70 of the screen 30 is located inside the stagnation zone 74. During operation of the mass transfer column 10, liquid flows out of the outlet opening 62 in the form of a liquid jet, which strikes the surface of the screen 64 essentially tangentially at the impact region 66, forming a thin, flowing liquid film that flows down the screen 64 to the drip edge 70. Droplets or drips formed at the drip edge 70 fall onto the surface of the packing 12 located immediately below the drip edge 70 of the screen 64. Because of the curvature, the gas 20 is guided by the screen 30 away from the thin liquid film flowing down the surface of the screen 64, so that the liquid film is not, or at least only slightly, disturbed by the rising gas 20. As such, the droplets formed at the drip edge 70 fall into the packing 12 below without being carried away by the rising gas 20, or at least essentially none of them. [Explanation of symbols]

[0054] 10 Separator / Mass Transfer Column 12 Filling 14 Liquid distributor 16 Front distributor member 17 Prior art pre-distributor element 18 Distributor member 20 Gases 22,22' Gas partial flow 24 liquid 26 Supply Line 28 Conventional trough 30 Prior art bulkhead 32 First chamber according to the prior art 32' Second chamber according to the prior art 34 Overflow slit 36 First Trough 38 Second Trough 40 First side wall of trough 42 Second side wall of the trough 44 Trough bottom wall 46 Discharge opening 48 Front wall of trough 50 Top of the trough 52,52' Trough upper edge / overflow edge 54 Trough overflow means 56 Trough deflector 58 Third Trough 60 Side wall of trough of distribution member 62 outlet opening of trough of distribution member 64 Distribution member screen 66 Screen Collision Area 68 Upper end of distribution member 70 Drip edge of distribution member screen 72,72' Distribution member screen skirt 74 Stagnation Zone

Claims

1. A liquid distributor (14) for a separation device (10), said liquid distributor (14) comprising at least one pre-distributor member (16) and a plurality of distributor members (18), said at least one pre-distributor member (16) being arranged above said plurality of distributor members (18), said at least one pre-distributor member (16) comprising at least two troughs (36, 38, 58) each comprising a plurality of discharge openings (46), each two of said at least two troughs (36, 38, 58) being connected to each other, said at least A first trough (36) of the two troughs has an overflow means (54) and at least one deflector (56) attached to the overflow means (54) or to a side wall (42) of the first trough (36) of the at least two troughs, and a second trough (38) of the at least two troughs has an upper edge, and at least one deflector (56) attached to the overflow means (54) of the first trough (36) is attached to the upper edge (52) of the second trough (38). , 52′) to the second trough (38), so that when the liquid level in the first trough (36) reaches the overflow means (54), liquid flows from the first trough (36) over the overflow means (54) or the side wall (42) and the at least one deflector (56) into the second trough (38), and the distributor member (18) includes a plurality of distributor members (18) arranged at least substantially parallel to one another, and the plurality of distributor members (18) are arranged in a direction parallel to one another. The liquid distributor (14) has the form of a hollow box having two side walls (40, 42) and two front walls (48) and a bottom wall (44) connected to each other, the bottom wall (44) and / or one of the side walls (40, 42) having a plurality of discharge openings (46), and an upper surface opposite the bottom wall (44) being arranged open so that liquid flowing through the plurality of discharge openings (46) of the at least two troughs (36, 38, 58) of the front distributor member (16) flows into the plurality of distributor members (18) through the upper surface.

2. 2. The liquid distributor (14) of claim 1, wherein at least the first trough (36) and the second trough (38) each have two side walls (40, 42), at least the first trough (36) and the second trough (38) each have a bottom wall having the plurality of discharge openings (46), and the bottom walls of at least the first and second troughs (36, 38) are flat and essentially aligned with each other, where essentially aligned with each other means that the bottom wall of the second trough (38) is in the same plane as the bottom wall of the first trough (36) or in a plane below or above the plane of the bottom wall of the first trough (36) that is not more than 10% of the height of the highest side wall (40) of the first trough (36).

3. 3. The liquid distributor (14) of claim 1 or 2, wherein at least the first trough (36) and the second trough (38) contact each other and are connected to each other by each of their side walls (40, 42).

4. 4. A liquid distributor (14) according to any one of claims 1 to 3, wherein at least one of the first trough (36) and the second trough (38) has the form of a hollow box having two side walls (40, 42), two front walls (48) and a bottom wall (44) connected to each other, the bottom wall (44) having a plurality of discharge openings (46), and an upper surface opposite the bottom wall (44) being open.

5. The liquid distributor (14) of any one of claims 1 to 4, wherein the overflow means (54) comprises one or more selected from the group consisting of an overflow edge, an overflow slit, an overflow hole, and any combination of two or more thereof.

6. 6. The liquid distributor (14) of claim 5, wherein the overflow means (54) of the first trough (36) includes an overflow edge (52), one of the two side walls (40, 42) of the first trough (36) is higher than the other of the two side walls (40, 42), the overflow edge (52) is an upper edge of the lower side wall (42), and at least one deflector (56) is attached to the overflow edge (52) or the side wall (42) and extends from the lower side wall (42) of the first trough (36) to the second trough (38) at an angle greater than 0° and less than 90°.

7. 7. The liquid distributor (14) of claim 6, wherein the first trough (36) has one deflector (56) attached to the overflow edge (52) or the side wall (42) and extending over at least 50% of the length of the overflow edge (52).

8. 6. The liquid distributor according to claim 5, wherein the overflow means includes several overflow slits provided in an upper portion of one of the side walls of the first trough, and the at least one deflector is attached to the overflow means or the side wall so that liquid flowing through the overflow slits flows over an upper surface of the at least one deflector, the at least one deflector extending from the side wall of the first trough provided with the overflow slits to the second trough at an angle greater than 0° and less than 90°, and the overflow slit extends substantially vertically downward from the upper edge of one of the side walls of the first trough.

9. 9. The liquid distributor (14) of claim 8, wherein the first trough (36) has one deflector (56) attached to the side wall (42) of the first trough (36) on which the overflow slit (34) is provided and extending over at least 50% of the length of the side wall (42) of the first trough (36) on which the overflow slit (34) is provided.

10. The at least one pre-distributor member (16) includes three troughs (36, 38, 58) consisting of a first trough (36), a second trough (38), and a third trough (58), each trough including two side walls (40, 42), the first trough (36) and the second trough (38) contacting each other and connected to each other by each of their side walls (40, 42), the second trough (38) and the third trough (58) contacting each other and connected to each other by each of their side walls (40, 42), the first trough Each of the first trough (36) and the second trough (38) has an overflow means (54) and at least one deflector (56) attached to the overflow means (54) or the side wall (42), and each of the second trough (38) and the third trough (58) has an upper edge, and the at least one deflector (56) attached to the overflow means (54) or the side wall (42) of the first trough (36) directs water from above the upper edge of the second trough (38) to the second trough. (38) so that when the liquid level in the first trough (36) reaches the overflow means (54), liquid flows from the first trough (36) over the overflow means (54) and the at least one deflector (56) into the second trough (38), and the overflow means (54) of the second trough (38) or at least one deflector (56) attached to the side wall (42) directs liquid from above the upper edge of the second trough (38) into the third trough (38).

7. The liquid distributor (14) of claim 5 or 6, wherein the first trough (36) has a height greater than the second trough (38), and the second trough (38) has a height greater than the third trough (58), so that when the liquid level in the second trough (37) reaches the overflow means (53), liquid flows from the second trough (38) over the overflow edge (52) and the at least one deflector (56) into the third trough (58).

11. 11. The liquid distributor (14) of claim 1, wherein the liquid distributor (14) comprises one to four pre-distributor members (16), the distributor members (18) being arranged adjacent to one another substantially in a plane.

12. 2. The liquid distributor (14) according to claim 1, comprising a plurality of further distributor elements (18) in the form of a hollow box having two side walls (40, 42), two front walls (48) connected to each other, and one or two bottom walls (44), wherein the bottom wall (44) and / or one of the side walls (40, 42) has a plurality of discharge openings (46) for the outflow of liquid in the form of jets, and the top surface opposite the bottom wall (44) is open, and liquid flowing through the discharge openings (46) of the plurality of distributor elements (18) flows through the top surface into the further plurality of distributor elements (18).

13. 13. A column (10) for mass transfer, the column (10) comprising at least one packing and at least one liquid distributor (14) according to any one of claims 1 to 12, or comprising a reactor comprising one or more catalyst beds and at least one liquid distributor (14) according to any one of claims 1 to 12 for distributing liquid above the one or more catalyst beds.

14. A method for separating at least two fluids, carried out using at least one column (10) according to claim 13.

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