Liquid dispenser

Abstract

A gravity liquid dispenser comprising: a lower plate provided with apertures through which liquid exits the dispenser to flush a lower element; parallel parallelepiped flues specialized for the passage of upstream gases, thereby defining a tank for the liquid above the lower plate, these flues being provided on the upper portion with closure means such that the liquid can be deflected; the flues are distributed on the whole central part with the circular cross section of the lower plate, so that a peripheral channel is released on the periphery of the lower plate, and the peripheral channel is in fluid connection with the groove; a plurality of caps capable of directing the liquid collected above the tanks towards the peripheral channel, each cap having an elongated rectangular shape comprising two ends, with only one cap per tank, the caps being closed at only one end such that at least a majority of the collected liquid flows towards the peripheral channel; the cap is oriented at an acute angle or zero angle to the horizontal.

Description

Technical Field

[0001] The present invention relates to the field of equipment for contacting fluids. Towers or columns for contacting gases / liquids sometimes use packing to improve the heat and mass exchange between the liquid and the gas. These towers are typically used for heat transfer, distillation, absorption or stripping applications. When packing is used, a distributor is also used, whose main function is to evenly distribute the liquid over the packing so as to best utilize the contact surface provided by the packing as a support for the liquid while allowing the gas to pass through the gas passage, also called the flue. Gravity distributors are by far the most widely used.

[0002] Therefore, distributors are used at the liquid inlet, but they are also used from a certain segment height, from which the distribution is no longer considered uniform enough to provide a satisfactory exchange level. Therefore, a device called a collector is used to collect the liquid, which then feeds the distributor. When the collector and distributor are integrated together to save height, the device is called a redistributor.

[0003] Redistributors redistribute liquid flows evenly. However, they also homogenize the composition and temperature of the liquid horizontally to a certain extent. This function is sometimes essential for the proper functioning of a column. This is especially true for complex distillations with components that have very similar boiling points, or when the goal is to achieve very high purities on one side or the other of a distillation section. In these cases, maldistribution of the components can have a significant impact on the performance of the column.

[0004] In general, it is not necessary to mix all the liquid in the column at one point. By mixing only a small portion of the liquid, an almost complete correction can be achieved. The difficulty lies in mixing over long horizontal distances, and ideally in both directions of the plane at a reduced height.

[0005] In addition, the horizontal velocity at the distributor perforation is limited. Specifically, too large a horizontal velocity is likely to produce flow differences in each perforation. Background Art

[0006] There are devices that promote mixing of liquids and thus homogenization of their levels. In general, separate collectors and distributors have better mixing capabilities. Specifically, in the case of collectors, all liquid flows are usually directed into one pipe or a few pipes. However, the columns that are sensitive to maldistribution are usually those that require large exchange surfaces, where vertical compactness becomes a major challenge.

[0007] To ensure uniformity of flow, it is necessary to have the same hydrostatic head above each perforation. To this end, the most robust solution is to achieve liquid-tight hydraulic continuity via a channel connecting the various distribution areas together. This channel usually passes through the center of the distributor or occupies its periphery over its entire circumference.

[0008] To promote uniformity of composition relative to a standard redistributor, a ramp and baffle system is sometimes designed to mix the liquid in the redistributor.

[0009] In the case of a distributor comprising a flue with a rectangular cross section, mixing in the main direction of the flue is more easily promoted than mixing in the transverse direction. It is sometimes common practice to alternate the orientation of the distributor so that mixing is carried out in both directions of the plane of two consecutive packing sections. However, this practice brings architectural design constraints, especially for the inlet and outlet of gases or liquids.

[0010] Redistributors with mixing functions are sometimes manufactured with an outer ring for collecting liquid that accumulates on the walls and a cap that directs some of the liquid toward the center.

[0011] Recently, a redistributor-mixer has been designed so that part of the liquid collected on both sides of the tower is directed to the other end of the tower in the transverse direction of the flue. This device makes it possible to homogenize the composition in a compact redistributor. However, it cannot directly support the packing of the upper section. It is necessary to add an additional crossbeam to it. In addition, the design is more complicated due to the presence of weirs of multiple sizes and the upper peripheral channels of complex shape. Summary of the invention

[0012] Purpose of the Invention

[0013] The invention described herein is directed to a simple apparatus for distributing liquid reflux to a vapor-liquid contacting column section with good flow uniformity and improved mixing of the components relative to the prior art, but without compromising volume.

[0014] Disclosure and advantages of the invention

[0015] Relative to the simple redistributor with a basic homogenizing action described in Jafari, S. et al. (2017) "CFD study of mixing performance of redistribution systems for packed columns", the cap enables mixing of the components in the trough direction and closes one end of the cap to promote liquid flow through the other end and optionally direct them to peripheral channels by alternating orientation, or also promotes mixing of the components in the lateral direction over usually three troughs, while maintaining the compactness of a solution with separate collectors and distributors and having a geometry that is easy to manufacture (number and complexity of parts and components).

[0016] Compared to the redistributors described in US5752538 and US5132055, it is advantageous that the liquid is distributed over three grooves in the lateral direction.

[0017] Furthermore, according to the design, the liquid flow under the cap is less turbulent than the liquid flow obtained by the groove formed by the guide plate. Specifically, the liquid has only one main flow direction and a larger discharge space, including part of the peripheral channel and part of the groove.

[0018] Although the lateral mixing is not as good as that described in US 1 1426676, the distributor of the present invention is less complex and includes supports for the filler sections without the need for additional cross beams.

[0019] Additionally, the cap enhances the structural rigidity of the distributor by further securing the gas flue.

[0020] According to one subject of the present invention, there is provided a gravity liquid dispenser, comprising:

[0021] a lower plate, which is provided with orifices through which the liquid leaves the distributor in order to flush lower elements, such as the lower packing section,

[0022] parallel parallelepiped flues, designed specifically for the passage of ascending gases, delimiting above the lower plate a trough for the liquid, these flues being provided with closing means in the upper part, making it possible both to deflect the liquid, for example, descending from a packing section above the distributor, and to preferably mechanically support this packing section,

[0023] the flues are distributed over the entire central portion of the lower plate, which has a circular cross section, thereby leaving a peripheral channel at the periphery of the lower plate, which is in fluid connection with the grooves,

[0024] A plurality of caps capable of directing liquid collected above the troughs to the peripheral channels, each cap having an elongated rectangular shape with two ends, wherein:

[0025] o each trough has only one cap, each cap being closed at one end only and optionally inclined so that at least a large part of the collected liquid flows towards the peripheral channel,

[0026] o the cap is oriented at an acute or zero angle to the horizontal, and

[0027] o The closed ends of the caps are arranged alternately from one groove to the other.

[0028] According to other optional aspects:

[0029] at least one of the caps covers / hides at most three quarters of the surface of the slot,

[0030] the distributor comprises a baffle located at the outlet of at least one of the caps and above the perforated plate in order to limit disturbances in the liquid level due to liquid falling in case of low liquid levels,

[0031] some caps are located between two adjacent gas flues and have a length less than or equal to the length of at least one of the two adjacent gas flues,

[0032] each cap has a flat bottom oriented at an angle between 0° and 30° relative to the surface of the plate, or even at an angle between 0° and 10° relative to the surface of the plate,

[0033] the caps are oriented at an acute angle to the horizontal and are oriented alternately toward one side or the other of the plate from one slot to the next,

[0034] a portion, or even a majority, of the cap is positioned so that liquid leaves the cap at one end of two adjacent gas flues, thereby draining the liquid directly into the peripheral channel,

[0035] • Each cap covers at least two thirds of the surface of the trough, optionally the entire surface of the trough.

[0036] According to the present invention, there is provided a fluid contact tower comprising at least one distributor as described above, a liquid discharge device located above the distributor, and a structured packing section located below the distributor.

[0037] According to another subject of the invention, there is provided a method for contacting a gas and a liquid in a column as described above.

[0038] The column may include a structured packing section located above the distributor, the packing section being supported by the enclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The present invention is described in more detail with reference to the accompanying drawings.

[0040] [ Figure 1 ] shows a redistributor 1 according to US5645770, whose cap R also serves as a closing device for the gas flue C placed on the plate P. This solution is relatively simple, but does not include a supporting function for the upper section. In addition, it exhibits a weak structural rigidity, without the addition of a parallelepiped flue passing through the assembly.

[0041] [ Figure 2 ] shows a redistributor 1 according to US 11426676. A fine mixing of the liquid components is possible by collecting a portion of the liquid via a closing device for closing the gas flue and a segmented upper peripheral channel. However, it is quite complex and requires the addition of a crossbeam assembled with the assembly (usually by welding) to support the upper section.

[0042] [ Figure 3 ]、[ Figure 4 ]and[ Figure 5 ] is a top view of a dispenser according to the present invention.

[0043] [ Figure 6 ]and[ Figure 7 ] represents an embodiment of the present invention viewed from the side. DETAILED DESCRIPTION

[0044] Figure 3 A gravity liquid dispenser 1A is shown comprising:

[0045] a lower plate P provided with orifices through which the liquid leaves the distributor in order to flush the lower packing section,

[0046] Nine parallel parallelepiped flues C, dedicated to the passage of ascending gases, delimiting the liquid trough above the lower plate, the upper part of these flues C being provided with closing means both to deflect the liquid descending from the filler section above the distributor and to mechanically support this section.

[0047] The flues C are distributed over the entire central portion of the lower plate P, which frees up a peripheral channel P at the periphery of the lower plate which integrates a plurality of caps R which direct the liquid collected above the troughs towards the peripheral channel P.

[0048] Each trough has only one cap R which is tilted (as shown) and / or closed at only one end so that most of the collected liquid flows towards the peripheral channels.

[0049] The closed ends alternate from one slot to another, so if the left end of the cap in one slot is closed, the right end of the cap in the adjacent slot will be closed, and vice versa. Thus, the caps drain liquid into the peripheral channels in a balanced manner.

[0050] The cap may be horizontal or may be at an acute angle to the horizontal of less than 30° or even less than 10°, the plate P being oriented horizontally.

[0051] In this example, the caps R1, R2 are oriented at an acute angle to the horizontal and are oriented alternately toward one side or the other of the plate from one slot to the next. Thus, the caps R1, R2 have an alternating gradient. Thus, the lowest ends of the four caps R1 are oriented toward one edge of the plate, while the lowest ends of the five caps R2 are oriented toward the opposite edge.

[0052] A single cap R1 , R2 covers at most the entire surface of the groove, but preferably only a part, for example at least two thirds of the groove surface.

[0053] Optionally, a baffle may be arranged at the end where the liquid leaves the cap and above the perforated plate in order to limit disturbances in the liquid level due to liquid falling down at low liquid levels.

[0054] exist Figure 3 In a variation of the present invention, except that the length of the central cap-shaped object is the same as the length of the two adjacent flues, the lengths of the other cap-shaped objects are shorter than one adjacent flue and longer than the other adjacent flue.

[0055] exist Figure 4 In a variation of , the three central caps are shorter than the adjacent flues.

[0056] The cap is preferably in contact with the vertical wall of the flue.

[0057] Figure 5 The dashed arrows in the figure depict the liquid leaving the cap and being distributed through the peripheral channels to the Figure 3 A path among three connected slots.

[0058] exist Figure 6 In Figure 4 The top of each cap is blocked to prevent liquid from being discharged from the wrong side. The top of the flue C is pierced with a plurality of openings to allow the gas ascending in the tower to pass through.

[0059] exist Figure 7 In the Figure 5 The version in .

Claims

1. A gravity liquid dispenser (1), comprising: a lower plate (P) provided with orifices through which liquid leaves the distributor in order to flush lower elements, such as the lower packing section, parallel parallelepiped flues (C) dedicated to the passage of ascending gases, defining above the lower plate a channel for the liquid, these flues being provided with closing means on the upper part, making it possible both to deflect the liquid, for example, descending from a packing section above the distributor, and to preferably mechanically support this packing section, the flues are distributed over the entire central portion of the lower plate, which has a circular cross section, thereby leaving a peripheral channel at the periphery of the lower plate, which is in fluid connection with the grooves, a plurality of caps (R, R1, R2) capable of directing liquid collected above the trough towards the peripheral channel, each cap having an elongated rectangular shape with two ends, wherein: o each trough has only one cap, each cap being closed at one end only and optionally inclined so that at least a major part of the collected liquid flows towards the peripheral channel, o the cap is oriented at an acute angle or zero angle to the horizontal, and o The closed ends of the caps are arranged alternately from one groove to another.

2. The dispenser according to claim 1, wherein At least one of the caps (R, R1, R2) covers at most three quarters of the surface of the groove.

3. A distributor according to claim 1 or 2, comprising baffles located at the outlet of at least one cap (R, R1, R2) and above the perforated plate (P) to limit disturbances to the liquid level due to liquid falling at low liquid heights.

4. The dispenser according to any one of claims 1 to 3, wherein: Some caps (R, R1, R2) are located between two adjacent gas ducts (C) and have a length less than or equal to the length of at least one of the two adjacent gas ducts.

5. The dispenser according to any one of claims 1 to 4, wherein: Each cap (R, R1, R2) has a flat bottom oriented at an angle between 0° and 30°, or even between 0° and 10° relative to the surface of the plate (P).

6. The dispenser according to claim 5, wherein: The caps (R, R1, R2) are oriented at an acute angle relative to the horizontal and are oriented alternately towards one side or the other of the plate (P) from one slot to the next.

7. A dispenser according to any one of the preceding claims, wherein: Some or even most of the caps are positioned so that liquid leaves the caps at one end of two adjacent gas flues, draining the liquid directly into the peripheral channel.

8. A dispenser according to any one of the preceding claims, wherein: Each cap (R, R1, R2) covers at least two thirds of the surface of the groove and optionally covers the entire surface of the groove.

9. A fluid contact tower comprising at least one distributor (1) according to any one of claims 1 to 8, a liquid discharge device located above the distributor and a structured packing section located below the distributor.

10. The fluid contact tower according to claim 9, comprising a structured packing section above the distributor (1), the structured packing section above the distributor being supported by a closing device.

11. A method for contacting a gas and a liquid in a fluid contact tower according to claim 9 or 10.

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