Fluid distribution system

[0001] The present invention relates to a liquid distribution system in accordance with the preamble of claim 1.

[0002] In the known pipe-type sprinkler system, a plurality of pipes with a plurality of openings directed at an angle upwards, through which acid flows radially, extend from the main pipe of the distributor. By means of deflector plates attached to the pipes, these streams are directed downwards to a fixed bed.

[0003] Such systems are used, for example, for the absorption of SO3 or steam in countercurrent in sulfuric acid in a fixed bed tower. In the head of e.g. a cylindrical container, the absorption acid is evenly distributed on the cross-section of the device by means of a sprinkler system and filtered through a solid bed from top to bottom. From the gas flowing in the counter-current upwards, the dripping acid absorbs SO3, with correspondingly increasing acid concentration, or water, whereby the acid is diluted. In standard configurations, the absorber is a tower with a fixed bed, built as a countercurrent device, the jacket of which is divided into three zones: the bottom part is formed by a sump with an acid outlet, the middle part, for example, contains a solid bed on the grate through which the acid, which is evenly distributed through the sprinkler system located on top of the fixed bed, filtered down. The acid inlet to the sprinkler system and the gas outlet are located above the fixed bed. The known problems of such systems are the limited surface of the gas outlet, which leads to an undesirable local increase in gas velocity and thus promotes the entrainment of acid droplets or mists.

[0004] From US Patent Document US 2004/0182013 A1, a spreading system is known in which liquid is discharged without pressure from a plurality of openings in the side wall of the spreader through an opening at the top and is directed to the bottom edge of the eaves through a transversely curved mesh structure, the mesh structure passes through the distributor channel to form a throttle. This device, on the one hand, connects with the problem of entraining small drops of acid and mists, and on the other hand, the individual elements of the spreader that make up the spreader chutes and the mesh structure require too much space, which leads to a reduction in the area available for gas flow.

[0005] From US Patent No. 5906773, a liquid distribution system is known in which liquid is guided from a spreader chute that has two holes in the wall arranged one above the other at a certain distance and leading to a vertical pipe leading to the surface of an inclined deflector, on which a valve is formed, which should additionally assist in the distribution of liquid. The liquid therefore flows over the vertical guide plate 7 to the surface of the filling bed. In addition to the space requirements of these spreader components, there is also the problem of entraining liquid droplets or mists.

[0006] A similar configuration of the countercurrent column is disclosed in US Patent No. 6575437 B2, in which the liquid is delivered to the bed as a layer, without pressure, through a deflector plate located transversely to the distributor chute.

[0007] In the spreader tubes known from US Patent No. 5439620, the liquid flows out of the openings in their upper surface and flows on the lateral surfaces located transversely to the distribution pipes, which have a serrated eaves edge, on the surface of the bed. The desired even distribution of liquid over the entire length of the spreader tube is not effectively ensured. Another problem here is accurate pressure control to avoid splashing liquid from the hole.

[0008] Publication document WO 02/083260 of the international patent application discloses a system according to the preamble of claim 1. A liquid spreader for use in a mass transfer column has a mass transfer bed located in the inner open area of ​​the column. The liquid distributor is equipped with supply reservoirs that supply the liquid stream to a plurality of longitudinal gutters that are separated from each other and which extend in parallel in the column. A plurality of openings are provided in the floor and side walls of the supply hopper for supplying liquid to the gutters. The gutters are located under the supply hopper and perpendicular to it.

[0009] Publication Document WO 01/89655 of the international patent application discloses a liquid spreader body for columns in which substance and heat exchange takes place. The liquid distributor body includes several channels that are arranged in the cross-section of the column and can be filled with the liquid to be distributed. The liquid dispenser in the column comprises a central conduit and several bypass conduits arranged in said column. The bypass lines have holes in their side walls through which the pipes are routed. During operation, liquid flows from said central conduit to said bypass pipes and bounces off the deflecting elements. The liquid then flows down towards the bed. The conduit, bypass lines and biasing element are arranged perpendicular to each other so that the free area available for gas flow is automatically reduced.

[0010] US Patent Document US 2001/0028121 A1 relates to a stream spreader for distributing liquid to a solid bed in a process column. The spreader comprises an elongated, centrally located supply hopper having gutters arranged under said supply hopper and extending across the column which is again perpendicular to the longitudinal direction of said supply hopper. Each of the side walls of said gutters has a plurality of openings through which liquid can be discharged. The liquid spreader includes discharge pipes attached to the side walls of the gutters, which significantly exceed the width of the gutter.

[0011] European Patent Document EP 1 323 467 A1 discloses a device for exchanging material and / or energy in a washing column. Individual fabric networks contain vertical wires that are directed upwards outside the network system. These wires are bent at the ends and suspended in the associated channel of the spreader. This spreading mechanism is located on the outer side walls of the spreader channel, thus exceeding the width of this spreader element in the horizontal direction.

[0012] Therefore, the object of the present invention is to enable a more efficient flow of gas flowing in the counter-current. In addition, it is intended to be achieved rather

Even distribution of the liquid throughout the entire cross-section of the bed with little construction effort, while minimizing the amount of liquid droplets or fog entrained by the gas stream.

[0013] According to the present invention, a liquid distribution system comprising the features of claim 1 is provided.

[0014] In this way, a situation is achieved in which drops of liquid or mists generated, when liquid flows out of the nozzles, are trapped in a substantially closed channel of the distributor and do not get into the gas phase. As a result, the gas flow rate can be increased and thereby the column diameter can be reduced, which leads to cost savings. Uneven liquid outflow from the nozzles is compensated by the liquid level created in the distributor channel and by a guide element adjacent to it over the entire length of the distributor element. As a result, a controlled even layer of liquid is fed to the bed. The distributor channel adheres from the bottom to the distributor element and its width does not significantly exceed the diameter of the distributor element. In this way, the free area at the liquid inlet of the filling bed is maximized to allow gas to flow in countercurrent. The specific acid inlet relative to the bed per square meter is up to 10 times, preferably 2 to 3 times higher compared to other sprinkler systems.

[0015] Preferably, the nozzles of the spreader element open downwards into the spreader channel at an angle above the liquid level, so that the liquid streams collide with the side wall of the spreader channel. This promotes more even liquid delivery along the length of the distributor channel.

[0016] To further prevent the production of unwanted particles of liquids or mists, the guide element, which may for example be a guide plate, extends into the bed, for example to a depth of about 100 mm.

[0017] For uniform distribution of liquid by avoiding undesirable transfer of acid particles into the gas stream, it is advantageous if the liquid level in the spreader channel is between 10 and 100 mm, preferably between 15 and 80 mm, above the discharge gap.

[0018] The width of the outlet gap of the spreader channel is, for example, between about 3 and 20 mm, preferably between about 5 and 15 mm.

[0019] The distributor element used, many of which may be arranged at a distance from each other above the bed, preferably have a diameter of from about 30 to 300 mm, more preferably from about 50 to 250 mm.

[0020] In practice, the operating parameters are preferably selected such that an overpressure of from about 0.2 to 6 bar, preferably from about 0.5 to 1 bar, is present in the spreader element.

[0021] According to the invention, a venting device may be provided in the distributor channel chamber to avoid undesired pressure build-up and liquid splashing from the discharge gap.

[0022] It is also advantageous if the spreader channel narrows downwards.

[0023] The system according to the invention may for example be used in a reactor in which liquid is filtered through a bed.

[0024] Further objects, features and advantages as well as possible applications of the invention can be deduced from the following description of the embodiment and drawing. All features described and / or illustrated as such form the subject of the invention, or in any combination thereof, also independently of their inclusion in the individual claims or their reference references.

Fig. 1 schematically shows, by way of example, a vertical cross section of a liquid spreader located above the bed, which consists of a spreader element, a spreader channel and a guide element, many of which can be arranged at a certain distance from each other and parallel to each other to form the entire sprinkler system according to invention.

Fig. 2 schematically shows a top view of a bed with a liquid spreader according to the invention.

[0025] The liquid spreader shown in the drawing comprises a spreader element 1 constituting a pressure pipe, which is preferably arranged parallel to the surface of the PA bed. The spreader element 1 must be supplied with the liquid to be distributed to the PA bed in such a way that there is an overpressure in the bed between about 0.2 and 6 bar, preferably between about 0.4 and 4 bar.

[0026] Without increasing the cross section, the distributor channel 2 connects to the distributor element 1 from below. At its lower tapered end 4, the spreader channel 2 has an outflow slot 3, extending substantially along its entire length, to collect liquid in the distributor channel 2 up to the level FP, which is sprayed into a closed vessel by means of nozzles 6 arranged along the distributor element 1 chamber 7 formed above the liquid level FP and defined by this level and walls of the distributor channel and the distributor element. The system is controlled such that the liquid level FP is kept between the maximum value FPmax (e.g. about 100 mm) and the minimum value FPmin (e.g. about 20 mm).

[0027] The nozzles 6 are arranged at an angle, so that the liquid stream first hits the side wall of the distributor channel 2. The liquid or vapor drops formed cannot be transferred to the counter-flowing gas, but are trapped at the liquid level and hence inside the chamber

7. In the figure, by way of translation, one nozzle direction is shown; of course, the nozzles can also be directed to the other side wall. It is also possible to use an alternating position of the nozzles or double nozzles in different directions. Similarly, the nozzles need not be arranged radially, but they can be tangentially arranged or directed in other directions.

[0028] The chamber 7 maintains a pressure that roughly corresponds to the pressure in the bed tower. By design configuration and pressure parameters, it can be ensured that an even layer of liquid flows out of the discharge gap 3 and that undesirable flooding of the PA bed is avoided. At its lower end, a plate-shaped guide element joining below the discharge gap

EP 2 173 464 B1

3, it sinks into the PA bed for example about 100 mm, so as to similarly avoid undesirable formation of liquid droplets or mists at this point.

In practical operation, the liquid level FP may for example be between 10 and 100 mm, preferably between 20 and 70 mm, the width of the discharge gap 3 may be between about 3 and 20 mm, preferably between about 8 and 10 mm, and the diameter of the spreader element 1 it may be between about 30 and 300 mm, preferably between about 50 and 250 mm.

[0029] In order to maintain the desired pressure in the chamber 7, it can be equipped with a venting device, and particularly preferably with an overflow line, so that the pressure cannot rise when too much liquid is supplied.

[0030] The chamber or its side walls may be configured differently than in figure 1, without departing from the actual idea of ​​the invention, namely in the form of releasing a rather undisturbed liquid stream from the chamber and passing a rather compact liquid stream to the bed.

[0031] In particular, the walls may have a symmetrical, tapered, straight or special shape. Similarly, the guide element 5 does not have to enter vertically into the bed plane, but can be placed at an angle. In addition, it is possible to use not one, but many outflow slots, and especially also many guide elements that are directed in different directions.

[0032] Similarly, the discharge gap need not be inclined, but it can be especially open directly downwards or sideways.

[0033] As shown in Fig. 2 by way of example, many elements (here four) of the spreader 1 side by side over the bed PA are provided here to distribute the liquid evenly throughout the entire cross section of the tower. The elements of the spreader 1 are fed with sulfuric acid through a common supply pipe 8.

[0034] In a particular aspect of the invention, the nozzles 6 may not have a uniform diameter or a uniform shape, but different diameters depending on the distance from the supply cord.

List of reference numbers [0035] spreader element spreader channel discharge gap end narrowed guide element nozzles chamber supply cord

FP liquid level

PA deposit

EP2 173 464 B1