Structured packing

Abstract

A corrugated structured packing sheet has a combination of corrugations including curves formed in the geometry of the corrugations in the lower edge region of the structured packing sheet and a surface texture on opposite faces of the structured packing sheet in the form of a grid of recessed and raised structures. Each recessed structure is separated from some or all adjacent ones of the recessed structures by a raised structure. The raised structures form rows of peaks and interconnected saddles. Microchannels extend along adjacent ones of the recessed structures and the interconnecting saddles. When used with the curved geometry of the corrugations in the lower edge region, the surface texture results in unexpected performance improvements.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 394,976, filed on August 4, 2022, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention relates generally to mass transfer columns and, more particularly, to structured packings for promoting mass and heat transfer between fluids in such columns. Background Art

[0004] Mass transfer towers are configured to contact at least two fluid streams so as to provide a product stream having a specific composition and / or temperature. As used herein, the term "mass transfer tower" is intended to encompass towers in which mass transfer and / or heat transfer are the primary objectives. Some mass transfer towers, such as mass transfer towers for multi-component distillation and absorption applications, contact a gas phase stream with a liquid phase stream, while other mass transfer towers, such as extraction towers, may be designed to promote contact between two liquid phases of different densities. Typically, a mass transfer tower is configured to contact an ascending vapor or liquid stream with a descending liquid stream, typically along a plurality of mass transfer surfaces disposed within the tower. Typically, these transfer surfaces are defined by structures disposed in the internal volume of the tower, which are configured to promote close contact between the two fluid phases. As a result of these mass transfer surfaces, the rate and / or degree of mass transfer and heat transfer between the two phases is enhanced.

[0005] Structured packing is a type of mass transfer surface that is typically used to enhance heat and / or mass transfer performance within a tower. There are many different types of structured packing, and most types include a plurality of corrugated structured packing sheets that are positioned in an upright parallel relationship and joined together to form a structured packing module having fluid channels formed along the intersecting corrugations of adjacent sheets. The structured packing modules may themselves form a structured packing layer that fills a horizontal internal cross-section of a mass transfer tower, or the packing modules may be in the form of individual bricks that are positioned end-to-end and side-by-side to form a structured packing layer. Multiple structured packing layers are typically stacked on top of each other with the orientation of the sheets in one layer rotated relative to the sheets in an adjacent structured packing layer.

[0006] When the vapor phase and the liquid phase flow through the structured packing layer, it is generally desirable to maximize the heat and / or mass transfer between the vapor phase and the liquid phase. This is generally achieved by increasing the specific surface area available for mass transfer and energy transfer. However, a fluid passing through a structured packing layer having a higher specific surface area will generally experience a higher pressure drop, which is undesirable from an operational perspective.

[0007] One way to improve the heat and / or mass transfer performance of structured packing without increasing the specific surface area of ​​the structured packing layer is to use various types of surface textures on the structured packing sheets. The surface texture facilitates the diffusion of the liquid phase on the surface of the structured packing sheet, which subsequently increases the heat and / or mass transfer between the liquid phase and the vapor phase. Typically a single type of surface texture is applied over the entire surface area of ​​the structured packing sheet.

[0008] One type of known surface texturing uses grooves that extend in a transverse direction parallel to the top and bottom edges of the corrugated structured packing sheet. A potential disadvantage of this type of surface texturing is that if the structured packing sheet is not flat, the grooves will be inclined from the horizontal and liquid traveling along the grooves will flow preferentially in one direction, resulting in uneven liquid distribution and reduced mass transfer efficiency.

[0009] Another type of surface texture that is generally more efficient in mass transfer than the groove type of surface texture comprises a uniform grid of recessed structures and raised structures, wherein each recessed structure is separated from an adjacent recessed structure by a raised structure. The recessed structures on one side of the structured packing sheet form raised structures on the opposite side of the structured packing sheet, and vice versa.

[0010] The raised structures surrounding the recessed structures form rows including peaks and interconnected saddles, wherein the saddles and recessed structures form rows of microchannels along which liquids flow preferentially. These rows and microchannels are tilted and angled to intersect the top and bottom edges of the structured packing sheet. It has been found that the spreading pattern of the liquid may be affected by these microchannels.

[0011] The capacity of structured packing layers may also be limited by their behavior when the vapor and liquid phases change their flow direction at the interface between vertically adjacent structured packing layers. Due to this change in flow direction, liquid may tend to accumulate at the interface and cause a reduction in capacity and performance, especially at higher liquid loadings.

[0012] One method for increasing the capacity of a structured packing layer and / or reducing the pressure drop at an interface involves modifying the geometry of the corrugations at the bottom of the structured packing layer. In one such variation, bends are formed in the geometry of the corrugations in the bottom portion and optionally the upper portion of the structured packing layer so that the angle of the corrugations relative to the vertical axis of the mass transfer tower gradually increases from the angle present in the body region of the structured packing layer to a larger angle at the lower edge and optionally the upper edge of the structured packing layer. This curved geometry in the corrugations reduces the premature accumulation of liquid at the interface of the structured packing layer and reduces the pressure drop that would occur at the interface if the curved geometry was not used. Summary of the invention

[0013] In one aspect, the present invention relates to a structured packing module comprising a plurality of structured packing sheets positioned in an upright parallel relationship to one another and a surface texture on the structured packing sheets. Each structured packing sheet comprises: opposite faces; an upper edge and a lower edge; a lower edge region adjacent to the lower edge; a body region located above the lower edge region; and corrugations formed by alternating peaks and valleys interconnected by corrugated sidewalls and extending in an inclined direction that forms an inclined angle relative to the upper edge and / or lower edge of the structured packing sheet. The structured packing sheets are constructed and arranged so that the corrugations of adjacent structured packing sheets in the structured packing sheet intersect at an angle to one another. Each structured packing sheet also includes a bend formed in the geometry of the corrugations in the lower edge region so that the angle of inclination of the corrugations relative to the lower edge gradually increases from the body region through the lower edge region. The surface texture on the structured packing sheet includes: a grid of recessed structures and raised structures in the body region, wherein each recessed structure is separated from some or all adjacent ones of the recessed structures by raised structures, the raised structures forming rows of peaks and interconnected saddles; and microchannels extending along adjacent ones of the recessed structures and interconnected saddles, the interconnected saddles being positioned between each of the adjacent ones of the recessed structures.

[0014] In another aspect, the present invention relates to a structured packing sheet, which includes: opposite sides; an upper edge and a lower edge; a lower edge region adjacent to the lower edge; a body region located above the lower edge region; a plurality of holes, the plurality of holes extending through the structured packing sheet; corrugations formed by alternating peaks and valleys, the peaks and valleys being interconnected by corrugated side walls and extending in an inclined direction, the inclined direction forming an inclined angle relative to the upper edge and / or lower edge of the structured packing sheet; bends formed in the geometry of the corrugations in the lower edge region so that the inclination angle of the corrugations relative to the lower edge gradually increases from the body region through the lower edge region; and a surface texture on the opposite side. The surface texture includes: a grid of recessed structures and raised structures, wherein each recessed structure is separated from some or all adjacent ones of the recessed structures by raised structures, the raised structures forming rows of peaks and interconnected saddles; and microchannels extending along adjacent ones of the recessed structures and interconnected saddles, the interconnected saddles being positioned between each of the adjacent ones of the recessed structures.

[0015] In yet another aspect, the present invention relates to a structured packing sheet comprising: opposite faces; an upper edge and a lower edge; a lower edge region adjacent to the lower edge; a body region located above the lower edge region; a plurality of holes extending through the structured packing sheet; corrugations formed by alternating peaks and valleys interconnected by corrugated side walls and extending in an inclined direction forming an inclination angle relative to the upper edge and / or lower edge of the structured packing sheet; bends formed in the geometry of the corrugations in the lower edge region such that the inclination angle of the corrugations relative to the lower edge gradually increases from the body region through the lower edge region; and a surface texture on the opposite face. The surface texture includes: a grid of recessed structures and raised structures, wherein each recessed structure is separated from some or all adjacent ones of the recessed structures by raised structures, the raised structures forming rows of peaks and interconnected saddles; and microchannels extending along adjacent ones of the recessed structures and interconnected saddles, the interconnected saddles being positioned between each of the adjacent ones of the recessed structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In the accompanying drawings which form a part of this specification and in which like reference numerals are used throughout the several views to designate like parts:

[0017] Figure 1 is a truncated side elevation view of a mass transfer column having a column shell taken in vertical section to show four structured packing layers of the present invention positioned in a stacked arrangement within the mass transfer column;

[0018] Figure 2 is a side perspective view of a corrugated structured packing sheet of the present invention, the corrugated structured packing sheet forming a portion of a structured packing module and having an embodiment of a surface texture of pores and a grid of recessed structures and raised structures, wherein for ease of viewing and understanding, the surface texture is representatively shown as covering only certain portions of the sheet, but may in fact cover the entire sheet;

[0019] Figure 3 is an enlarged, fragmentary view of a structured packing sheet of one embodiment having a surface texture comprising a network of recessed and raised structures in the form of pyramidal peaks and valleys;

[0020] Figure 3a It is along Figure 3 A cross-sectional view taken along line 3a-3a of ;

[0021] Figure 3b It is along Figure 3 A cross-sectional view taken along line 3b-3b;

[0022] Figure 4is an enlarged, fragmentary view of another embodiment of a structured packing sheet having a surface texture comprising a network of recessed and raised structures in the form of elongated ridge-like peaks and valleys;

[0023] Figure 4a It is along Figure 4 A cross-sectional view taken along line 4a-4a;

[0024] Figure 4b It is along Figure 4 A cross-sectional view taken along line 4b-4b;

[0025] Figure 5 is an enlarged, fragmentary view of a structured packing sheet of yet another embodiment having a surface texture comprising a grid of recessed and raised structures in the form of pyramidal peaks and valleys with higher saddles between rows of peaks and lower saddles between columns of peaks;

[0026] Figure 5a It is along Figure 5 A cross-sectional view taken along line 5a-5a;

[0027] Figure 5b It is along Figure 5 A cross-sectional view taken along line 5b-5b of ; and

[0028] Figure 6 is a front perspective view of another embodiment of the corrugated structured packing sheet of the present invention, and is similar to Figure 2 The structured packing sheet shown in the figure is different in that the structured packing sheet has Figure 2 In addition to the curved corrugations shown in the lower edge region, there are also curved corrugations in the upper edge region. DETAILED DESCRIPTION

[0029] Turning now to the more detailed drawings and first to Figure 1 A mass transfer tower suitable for use in mass and heat transfer processes is generally indicated by the numeral 10. The mass transfer tower 10 includes an upright outer shell 12 of generally cylindrical configuration, although other configurations, including polygonal shapes, are possible and within the scope of the present invention. The shell 12 has any suitable diameter and height and is constructed of one or more rigid materials that are advantageously inert or otherwise compatible with the fluids and conditions present during operation of the mass transfer tower 10.

[0030] The shell 12 of the mass transfer tower 10 defines an open interior region 14, in which the desired mass transfer and / or heat exchange occurs between the fluid streams. Typically, the fluid streams include one or more rising vapor streams and one or more descending liquid streams. Alternatively, the fluid streams may include both rising liquid streams and descending liquid streams. The fluid streams are directed into the mass transfer tower 10 via any number of feed lines (not shown), which are positioned at appropriate locations along the height of the mass transfer tower 10. One or more vapor streams may also be generated within the mass transfer tower 10, rather than being introduced into the tower 10 via feed lines.

[0031] The mass transfer column 10 will also typically include an overhead line (not shown) for removing vapor products or by-products and a bottoms stream exit line (not shown) for removing liquid products or by-products from the mass transfer column 10. Other column components that are typically present, such as feed points, side draws, reflux stream lines, reboilers, condensers, vapor horns, liquid distributors, etc., are not illustrated in the drawings because illustration of these components is not believed to be necessary for an understanding of the present invention.

[0032] One or more structured packing layers 16, comprising a plurality of individual structured packing sheets 18, are positioned within the open interior region 14 and extend across the entire horizontal interior cross-section of the mass transfer column 10. In the illustrated embodiment, four structured packing layers 16 are positioned in vertically stacked relationship with one another, but it will be appreciated that more or fewer structured packing layers 16 may be provided.

[0033] In one embodiment, each of the structured packing layers 16 is formed as a single structured packing module that extends completely across the entire horizontal interior cross-section of the column 10. In another embodiment, each structured packing layer 16 is formed as a plurality of individual structured packing modules (not shown), referred to as bricks, that are positioned in an end-to-end and side-by-side relationship to fill the horizontal interior cross-section of the mass transfer column 10.

[0034] The structured packing layers 16 are each suitably supported within the mass transfer column 10, such as on support rings (not shown) secured to the shell 12, on an underlying structured packing layer of the structured packing layer 16, or by a grid or other suitable support structure. In one embodiment, the lowest structured packing layer 16 is supported on a support structure, and the overlying structured packing layers 16 are stacked on top of each other and supported by the lowest structured packing layer 16.

[0035] Successive structured packing layers 16 are typically rotated relative to each other so that the individual structured packing sheets 18 in one of the packing layers 16 are positioned in vertical planes that extend at angles relative to vertical planes defined by the individual structured packing sheets 18 in one or more adjacent packing layers 16. The rotation angle is typically 45 degrees or 90 degrees, but can be other angles if desired. The height of each structured packing element 16 can be varied depending on the particular application. In one embodiment, the height is in the range of about 50 mm to about 400 mm.

[0036] The structured packing sheets 18 in each structured packing layer 16 are positioned in upright parallel relationship with each other. Each of the structured packing sheets 18 is constructed of a suitably rigid material (such as any of a variety of metals, plastics, or ceramics) having sufficient strength and thickness to withstand the process conditions experienced within the mass transfer column 10.

[0037] Also go to Figure 2 , each structured packing sheet 18 presents opposing front faces 20 and back faces 22, opposing upper and lower edges 24 and 26, and opposing side edges 28 and 30. Each structured packing sheet 18 has a plurality of parallel corrugations 32 extending along a portion or all of the associated structured packing sheet 18. The corrugations 32 are formed by alternating peaks 34 and valleys 36 and corrugation sidewalls 38 extending between adjacent ones of the peaks 34 and valleys 36. The peaks 34 on the front face 20 of each structured packing sheet 18 form valleys 36 on the opposite or back face 22 of the structured packing sheet 18. Likewise, the valleys 36 on the front face 20 of each structured packing sheet 18 form peaks 34 on the back face 22 of the structured packing sheet 18.

[0038] In the illustrated embodiment, the corrugations 32 of each of the structured packing sheets 18 extend along the entire height and width of the structured packing sheet 18 and have a generally triangular or sinusoidal cross-section. Adjacent ones of the structured packing sheets 18 in each structured packing layer 16 are positioned in a facing relationship so that the front face 20 of one of the structured packing sheets 18 faces the back face 22 of the adjacent structured packing sheet 18.

[0039] As described in more detail below, in one embodiment, such as Figure 2As shown, the geometry of the corrugations 32 in the lower edge region 40 adjacent the lower edge 26 of each structured packing sheet 18 is different from the geometry of the corrugations 32 in the adjacent body region forming the remainder of the structured packing sheet 18. In some embodiments, the lower edge region 40 may span 5% to 30%, 5% to 25%, or 5% to 20% of the vertical distance from the lower edge 26 to the upper edge 24 of each structured packing sheet 18. In other embodiments, the lower edge region 40 may span 20% to 60%, 20% to 50%, 25% to 45%, or 30% to 40% of the distance from the lower edge 26 to the upper edge 24 of each structured packing sheet 18.

[0040] In other embodiments, such as Figure 6 As shown, the geometry of the corrugations 32 in both the lower edge region 40 and the upper edge region 42 adjacent to the upper edge 24 of the structured packing sheet 18 is different from the geometry of the corrugations 32 in the remaining body region. In the illustrated embodiment, the lower edge region 40 spans a greater vertical distance than the upper edge region 42. For example, the lower edge region 40 may span 5% to 35%, 5% to 25%, 5% to 20%, or 30% to 35% of the distance from the lower edge 26 to the upper edge 24 of each structured packing sheet 18, and the upper edge region 42 may span 5% to 30%, 5% to 20%, 5% to 10%, or 20% to 25% of the distance from the lower edge 26 to the upper edge 24 of each structured packing sheet 18. In other embodiments, the lower edge region 40 and the upper edge region 42 may span the same distance. For example, in other embodiments, the lower edge region 40 and the upper edge region 42 may each span 5% to 35%, 5% to 25%, 5% to 20%, or 30% to 35% of the vertical distance from the lower edge 26 to the upper edge 24 of each structured packing sheet 18.

[0041] The adjacent structured packing sheets 18 are also arranged so that the corrugations 32 in each of the structured packing sheets 18 extend in a crisscross or cross-corrugated manner with those corrugations 32 in one or more adjacent structured packing sheets in the structured packing sheets 18. As a result of this arrangement, the corrugations 32 in each of the structured packing sheets 18 cross at an angle with the corrugations 32 of each adjacent structured packing sheet in the structured packing sheets 18 in the body region and in all or a portion of the lower edge region 40. In one embodiment, all of the peaks 34 of the corrugations 32 on the front face 20 of each of the structured packing sheets 18 are in contact with the peaks 34 of the corrugations 32 on the back face 22 of an adjacent structured packing sheet in the structured packing sheets 18 in the body region and in all or a portion of the lower edge region 40. Some of the peaks 34 of the corrugations 32 on the front face 20 of one of the structured packing sheets 18 are in contact with the peaks 34 on the back face 22 of an adjacent one of the structured packing sheets 18 .

[0042] The peaks 34 and valleys 36 of the corrugations 22 are generally formed as curved arcs, which can be defined by a tip radius. Generally speaking, for a given specific surface area, as the tip radius increases, the curved arcs of the peaks 34 and valleys 36 increase and the length of the corrugation sidewalls 38 between the peaks 34 and valleys 36 decreases conversely. The two corrugation sidewalls 38 of each corrugation 32 form a vertex angle. The tip radius, vertex angle, packing curl height, and peak 34 to peak 34 length are interrelated and can be varied to achieve the desired geometry and specific surface area. Generally speaking, as the curl height decreases, the number of structured packing sheets 18 contained in each structured packing layer 16 (or module) and the associated specific surface area increase.

[0043] The corrugations 32 are inclined in a direction that forms an acute angle relative to the upper edge 24 and / or the lower edge 26 of the structured packing sheet 18, or forms a vertical inclination angle in a region near the lower edge 26. The inclination angle can be selected for the needs of a specific application in which the structured packing sheet 18 is to be used. In one embodiment, the inclination angle in the body region can be in the range of 25 to 75 degrees. Specific examples of the inclination angle are about 30 degrees, about 45 degrees, and about 60 degrees. Since the upper edge 24 and the lower edge 26 of the structured packing sheet 18 are positioned vertically relative to the vertical axis of the mass transfer tower 10, the corrugations 32 are also inclined relative to the vertical axis of the mass transfer tower 10. At each position on the structured packing sheet 18, the inclination angle of the corrugations 32 relative to the upper edge 24 and / or the lower edge 26 of the structured packing sheet 18 and the acute angle at which the corrugations 32 are inclined relative to the vertical axis of the mass transfer tower 10 are complementary angles.

[0044] The geometry of the corrugations 32 in the lower edge region 40 adjacent the lower edge 26 of the structured packing sheet 18 is modified in a manner to increase the capacity of the structured packing layer 16 and / or to reduce the pressure drop when the fluid flows through the transition region at the interface between vertically adjacent structured packing layers 16. In one embodiment, such as Figure 2 As shown, a bend 44 is formed in the geometry of the corrugations 32 in the lower edge region 40 so that the inclination angle of the corrugations 32 relative to the lower edge 26 of the structured packing sheet 18 gradually increases from the body region through the lower edge region 40 of the structured packing sheet 18. The inclination angle of the corrugations 32 increases at the lower edge 26 of the structured packing sheet 18 to an inclination angle in the range of 65 to 90 degrees, 75 to 90 degrees, or 85 to 90 degrees.

[0045] Similarly, if Figure 6 As shown, bends 46 may also be formed in the geometry of the corrugations 32 in the upper edge region 42 of the structured packing sheet 18. The bends 46 in the upper edge region 42 are formed in a similar manner to the bends 44 in the lower edge region 40.

[0046] The bends 44 in the geometry of the corrugations 32 in the lower edge region 40 and the bends 46 in the geometry of the corrugations 32 in the upper edge region 42, if present, provide smooth changes in the direction of the rising vapor flow as it transitions between adjacent structured packing layers 16 and enters and exits the bulk region of the structured packing sheet 18. This smooth transition in the direction of the vapor flow reduces the premature accumulation of liquid at the interfaces of the structured packing layers 16 and reduces the pressure drop that would occur at the interfaces if a curved geometry were not used.

[0047] Some or all of the structured packing sheets 18 may be provided with a plurality of holes 48 extending through the structured packing sheets 18 to facilitate vapor and liquid distribution within the structured packing layer 16. Each hole 40 provides an open area to allow fluid to pass through the associated packing sheet 18. The holes 40 are generally evenly distributed on the structured packing sheets 18. In one embodiment, the holes 40 are provided on each structured packing sheet 18 in each structured packing layer 16.

[0048] The front face 20 and / or back face 22 of the structured packing sheet 18 may contain one or more different types of surface textures 49 to promote spreading and thereby maximize contact between the ascending and descending fluid streams. Figure 3 In one embodiment shown, the surface texture 49 includes a network of recessed structures 50 and raised structures 52 on the front face 20 and back face 22 of the structured packing sheet 18 . Figure 3Only some representative areas of the grid of recessed structures 50 and raised structures 52 are shown to allow the corrugations 32 to be easily seen, but it should be understood that the grid can cover the entire surface area of ​​the structured packing sheet 18 or a sufficient portion thereof to achieve the desired mass transfer efficiency. In one embodiment, the grid extends between the upper edge 24 and the lower edge 26 and between the side edges 28 and 30 so that the grid covers the entire surface area of ​​the structured packing sheet 18. In another embodiment, the grid covers 70% to 95% of the total surface area of ​​each structured packing sheet 18.

[0049] Each recessed structure 50 is separated from some or all adjacent recessed structures in the recessed structures 50 by a raised structure 52. The recessed structures 50 are arranged in parallel rows and may be positioned in a square, diamond, triangle, or other pattern. The raised structure 52 includes peaks 54 and interconnecting saddles 56. The peaks 54 may be generally conical (e.g., Figure 3 , Figure 3a and Figure 3b as well as Figure 5 , Figure 5a and Figure 5b as shown) or they may be elongated to form a ridge (as shown Figure 4 , Figure 4a , Figure 4b 20 ). Other shapes and / or configurations are possible and within the scope of the present invention. Typically, at least some portion of the raised structures 52 on the front face 20 is formed by at least some portion of the recessed structures 50 on the back face 22, and vice versa. Thus, each conical peak 54 can be formed by the conical end of one of the recessed structures 50 on the opposite side 20 or 22 of the structured packing sheet 18. Similarly, each ridge peak 54 can be formed by the ridge end of one of the recessed structures 50 on the opposite side 20 or 22 of the structured packing sheet 18.

[0050] The surface texture 49 includes microchannels 58 designated by arrows extending along adjacent ones of the recessed structures 50, and interconnected saddles 56 of the raised structures 52 positioned between adjacent ones of the recessed structures 50. These microchannels 58 may intersect with or extend parallel or substantially parallel to the corrugation valleys 36 to promote spreading of liquid across the front face 20 and back face 22 of the structured packing sheet 18. The orientation of the microchannels 58 with respect to the upper edge 24 and / or lower edge 26 of the structured packing sheet 18, and thus the orientation of the microchannels 58 relative to the corrugation valleys 36, is selected to optimize liquid spreading on the front face 20 and back face 22.

[0051] In one embodiment, some of the microchannels 58 extend in parallel with the corrugation valleys 26. For example, one-third or one-half of the microchannels 58 may extend in parallel with the corrugation valleys 26. In other embodiments, the microchannels 58 intersect the corrugation valleys 36 at an angle in the range of 20 degrees to 75 degrees, where the intersection angle is understood to be the smallest intersection angle among the possible intersection angles formed between the corrugation valleys 36 and the microchannels 52. In some embodiments, the angle may be in the range of 25 degrees to 70 degrees or 30 degrees to 65 degrees.

[0052] Two microchannels in the microchannel 58 extend across each other at a crossing angle at each recessed structure 50. In one embodiment, the crossing angle may be in the range of 50 to 140 degrees. In other embodiments, the crossing angle may be in the range of 70 to 130 degrees or 85 to 95 degrees. The microchannel 58 may extend linearly (e.g., Figure 3 ), they can extend in a zigzag manner (as Figure 4 ), or they may extend in other ways (e.g. Figure 5 For example, in Figure 6 In an embodiment, the interconnecting saddles 56 of the raised structures 52 are higher between rows of peaks 54 (which form a barrier to fluid flow to a greater extent) and lower between columns of peaks 54 (which form a barrier to fluid flow to a lesser extent), so that more fluid flows in the microchannels 58 between the rows of peaks 54.

[0053] Comparative tests were conducted using structured packing layers having two types of corrugations in the structured packing sheet and two types of surface textures on the structured packing sheet. ™ The surface texture on a Type B1 structured packing sheet was applied to a straight corrugated structured packing sheet and tested against the surface texture 49 described above applied to a straight structured packing sheet of the same type.

[0054] In another set of tests, the commercially available MONTZ-PAK ™ The surface texture on the B1 type structured packing sheet was applied to a structured packing sheet 18 having a bend 44 in the lower region 40 and tested against the above surface texture 49 applied to the same type of corrugated structured packing sheet 18 having a bend 44 in the lower edge region 40. ™ The surface texture on the B1 type structured packing sheet has a triangular pitch pattern and has finer and more densely packed concave and convex structures than the surface texture 49 described above.

[0055] Prior to testing, it was expected that the effect of surface texture on the performance of structured packing layers would be independent of the geometry of the corrugations in the structured packing sheet. ™ The performance of the surface texture on a Type B1 structured packing sheet is expected to be advanced to a structured packing sheet having turns 44 in the corrugations 32 as compared to the surface texture 49 on a straight corrugated structured packing sheet.

[0056] Surprisingly, this expectation was not confirmed by the comparative test data. Instead, the data indicate that the performance of the surface texture 49 when used in combination with the turns 44 in the corrugations 22 was unexpectedly superior to that predicted based on the comparative performance of the two surface textures when used with straight corrugation geometries. Thus, the comparative test data indicate that the surface texture 49 behaves differently depending on the geometry of the corrugations on the structured packing sheet, and that improved synergistic performance is achieved by the combination of the surface texture 49 and the corrugated structured packing sheet 18 having the turns 44 in the lower edge region 40.

[0057] This unexpected performance improvement can be seen in the standardized comparative test data presented in the table below, where the straight corrugated structured packing sheet is KOCH-GLITSCH ™ FLEXIPAC ® 250Y structured packing sheet, the curved corrugated structured packing sheet 18 has the bend 44 only in the lower edge region 40 and has the same properties as those of the commercially available MONTZ-PAK ™ The corrugated structure found in B1-250MN structured packing, MONTZ ™ Surface texture is commercially available for MONTZ-PAK ™ Surface texture on structured packing sheets of type B1, KOCH-GLITSCH ™ The surface texture is Figure 3 , Figure 3a and Figure 3b The overall example shown in the figure and used commercially in KOCH-GLITSCH ™ FLEXIPAC ® The above surface texture 49 on the 250Y structured packing sheet.

[0058] In the comparative test results depicted in Table 1, the MONTZ ™ The performance of the structured packing layer with surface texture was better than that of the structured packing layer with KOCH-GLITSCH at six out of eleven flow rates. ™The performance of the structured packing layer with the surface texture was comparable and was the same at two of the eleven flow rates. It is expected that this comparative performance between the two surface textures will also be seen when testing with a structured packing layer having bends 44 in the lower edge region 40. In other words, when the geometry of the corrugations is changed in the lower edge region, the MONTZ ™ Structured packing layers with surface texture are expected to outperform those with KOCH-GLITSCH ™ Structured packing layer with surface texture.

[0059] In contrast, as unexpectedly shown in Table 2, when the bend 44 is added to the corrugations 22 in the lower edge region 40, the KOCH-GLITSCH ™ The structured packing layer with surface texture outperformed the MONTZ packing layer at eight out of eleven flow rates. ™ The surface textured structured packing layer was the same at two of the eleven flow rates. This improvement in performance suggests that some type of synergistic interaction occurs when the surface texture 49 is used in combination with the turns 44 in the lower edge region 40 of the structured packing sheet 18.

[0060] Table 1

[0061]

[0062] Table 2

[0063]

[0064] From the foregoing it will be seen that this invention is one well adapted to attain all the ends and objects hereinbefore set forth, together with other advantages inherent to its structure.

[0065] It should be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by the present invention and is within the scope of the present invention.

[0066] Since many possible embodiments can be made in accordance with the present invention without departing from the scope of the invention, it is to be understood that all matter herein set forth or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Claims

1. A structured packing module, comprising: A plurality of structured packing sheets, the plurality of structured packing sheets being positioned in upright parallel relationship to one another, each structured packing sheet comprising: opposite side; upper and lower edges; a lower edge region adjacent to the lower edge; a body region located above the lower edge region; a plurality of apertures extending through the structured packing sheet; and corrugations formed of alternating peaks and valleys, the peaks and valleys being interconnected by corrugation side walls and extending in an inclined direction, the inclined direction forming an inclined angle relative to the upper edge and / or the lower edge of the structured packing sheet, the structured packing sheets being constructed and arranged so that the corrugations of adjacent ones of the structured packing sheets cross each other at an angle, a bend formed in the geometry of the corrugations in the lower edge region such that the angle of inclination of the corrugations relative to the lower edge increases gradually from the body region through the lower edge region; and The surface texture on the structured packing sheet comprises: a grid of recessed structures and raised structures in the body region, wherein each recessed structure is separated from some or all adjacent ones of the recessed structures by the raised structures, the raised structures forming rows of peaks and interconnecting saddles; and microchannels extending along adjacent ones of the recessed structures and the interconnecting saddles, the interconnecting saddles being positioned between each one of the adjacent ones of the recessed structures. 2 . The structured packing module according to claim 1 , wherein the inclination angle of the corrugations at the lower edge is in the range of 65 degrees to 90 degrees. 3 . The structured packing module of claim 1 , wherein the inclination angle of the corrugations at the lower edge is in the range of 75 degrees to 90 degrees.

4. A structured packing module according to claim 3, wherein the recessed structures are arranged in parallel rows, the interconnecting saddles of the raised structures within each row connecting adjacent recessed structures.

5. The structured packing module of claim 4, wherein each of the peaks of the raised structures is tapered and formed by a tapered end of one of the depressed structures on the opposite face of the structured packing sheet.

6. The structured packing module of claim 4, wherein each of the peaks of the raised structures is ridge-shaped and is formed by a ridge-shaped end of one of the depressed structures on the opposite face of the structured packing sheet.

7. The structured packing module of claim 4, wherein some of the microchannels extend parallel to the corrugation valleys.

8. The structured packing module according to claim 4, comprising: an upper edge region adjacent to the upper edge; as well as Another bend is formed in the geometry of the corrugations in the upper edge region such that the angle of inclination of the corrugations relative to the upper edge increases gradually from the body region through the upper edge region.

9. The structured packing module of claim 1 , wherein the lower edge region spans 5% to 30%, 5% to 25%, 5% to 20%, 20% to 60%, 20% to 50%, 25% to 45%, or 30% to 40% of the distance from the lower edge to the upper edge of the structured packing sheet.

10. The structured packing module of claim 1, wherein the plurality of holes are evenly distributed on the structured packing sheet.

11. A structured packing sheet, comprising: opposite side; upper and lower edges; a lower edge region adjacent to the lower edge; a body region located above the lower edge region; a plurality of apertures extending through the structured packing sheet; corrugations formed by alternating peaks and valleys, the peaks and valleys being interconnected by corrugation side walls and extending in an inclined direction forming an inclined angle relative to the upper edge and / or the lower edge of the structured packing sheet; a bend formed in the geometry of the corrugations in the lower edge region such that the angle of inclination of the corrugations relative to the lower edge increases gradually from the body region through the lower edge region; as well as A surface texture on the opposite side, the surface texture comprising: A grid of recessed structures and raised structures, wherein each recessed structure is separated from some or all adjacent ones of the recessed structures by the raised structures, the raised structures forming rows of peaks and interconnecting saddles; and microchannels extending along adjacent ones of the recessed structures and the interconnecting saddles, the interconnecting saddles being positioned between each of the adjacent ones of the recessed structures. 12 . The structured packing sheet according to claim 11 , wherein the inclination angle of the corrugations at the lower edge is in the range of 65 degrees to 90 degrees.

13. The structured packing sheet according to claim 11, wherein the inclination angle of the corrugations at the lower edge is in the range of 75 degrees to 90 degrees.

14. The structured packing sheet of claim 11 wherein the recessed structures are arranged in parallel rows, the interconnecting saddle portions of the raised structures within each row connecting adjacent recessed structures.

15. The structured packing sheet of claim 11, wherein each of the peaks of the raised structures is tapered and formed by a tapered end of one of the depressed structures on the opposite face of the structured packing sheet.

16. The structured packing sheet according to claim 15, wherein each of the peaks of the raised structures is ridge-shaped and is formed by a ridge-shaped end of one of the depressed structures on the opposite face of the structured packing sheet.

17. The structured packing sheet of claim 16, wherein some of the microchannels extend in parallel with the corrugation valleys. 18 . The structured packing sheet according to claim 16 , wherein two of the microchannels extend to cross each other at a crossing angle in the range of 50 degrees to 140 degrees at each recessed structure.

19. The structured packing sheet of claim 11, wherein the lower edge region spans 5% to 30%, 5% to 25%, 5% to 20%, 20% to 60%, 20% to 50%, 25% to 45%, or 30% to 40% of the distance from the lower edge to the upper edge of the structured packing sheet.

20. A structured packing sheet, comprising: opposite side; upper and lower edges; a lower edge region adjacent to the lower edge, wherein the lower edge region spans from 25% to 45% of the distance from the lower edge to the upper edge of the structured packing sheet; a body region located above the lower edge region; a plurality of apertures extending through the structured packing sheet; corrugations formed by alternating peaks and valleys, the peaks and valleys being interconnected by corrugation side walls and extending in an inclined direction forming an inclined angle relative to the upper edge and / or the lower edge of the structured packing sheet; a bend formed in the geometry of the corrugations in the lower edge region so that the inclination angle of the corrugations relative to the lower edge gradually increases from the body region through the lower edge region, the inclination angle at the lower edge being in the range of 65 degrees to 90 degrees; as well as A surface texture on the opposite side, the surface texture comprising: A grid of recessed structures and raised structures, wherein each recessed structure is separated from some or all adjacent ones of the recessed structures by the raised structures, the raised structures forming rows of peaks and interconnected saddles; and microchannels extending along adjacent ones of the recessed structures and the interconnected saddles, the interconnected saddles being positioned between each of the adjacent ones of the recessed structures, wherein the recessed structures are arranged in parallel rows, the interconnected saddles of the raised structures within each row connecting adjacent ones of the recessed structures.

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