Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J19/32—Packing elements in the form of grids or built-up elements for forming a unit or module inside the apparatus for mass or heat transfer
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F28—HEAT EXCHANGE IN GENERAL
  • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
  • F28F25/00—Component parts of trickle coolers
  • F28F25/02—Component parts of trickle coolers for distributing, circulating, and accumulating liquid
  • F28F25/08—Splashing boards or grids, e.g. for converting liquid sprays into liquid films; Elements or beds for increasing the area of the contact surface
  • F28F25/087—Vertical or inclined sheets; Supports or spacers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/32—Details relating to packing elements in the form of grids or built-up elements for forming a unit of module inside the apparatus for mass or heat transfer
  • B01J2219/322—Basic shape of the elements
  • B01J2219/32203—Sheets
  • B01J2219/3221—Corrugated sheets
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/32—Details relating to packing elements in the form of grids or built-up elements for forming a unit of module inside the apparatus for mass or heat transfer
  • B01J2219/322—Basic shape of the elements
  • B01J2219/32203—Sheets
  • B01J2219/32213—Plurality of essentially parallel sheets
  • B01J2219/32217—Plurality of essentially parallel sheets with sheets having corrugations which intersect at an angle of 90 degrees
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/32—Details relating to packing elements in the form of grids or built-up elements for forming a unit of module inside the apparatus for mass or heat transfer
  • B01J2219/322—Basic shape of the elements
  • B01J2219/32203—Sheets
  • B01J2219/32213—Plurality of essentially parallel sheets
  • B01J2219/3222—Plurality of essentially parallel sheets with sheets having corrugations which intersect at an angle different from 90 degrees
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/32—Details relating to packing elements in the form of grids or built-up elements for forming a unit of module inside the apparatus for mass or heat transfer
  • B01J2219/322—Basic shape of the elements
  • B01J2219/32203—Sheets
  • B01J2219/32224—Sheets characterised by the orientation of the sheet
  • B01J2219/32227—Vertical orientation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/32—Details relating to packing elements in the form of grids or built-up elements for forming a unit of module inside the apparatus for mass or heat transfer
  • B01J2219/322—Basic shape of the elements
  • B01J2219/32203—Sheets
  • B01J2219/32237—Sheets comprising apertures or perforations
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/32—Details relating to packing elements in the form of grids or built-up elements for forming a unit of module inside the apparatus for mass or heat transfer
  • B01J2219/322—Basic shape of the elements
  • B01J2219/32203—Sheets
  • B01J2219/32237—Sheets comprising apertures or perforations
  • B01J2219/32244—Essentially circular apertures
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/32—Details relating to packing elements in the form of grids or built-up elements for forming a unit of module inside the apparatus for mass or heat transfer
  • B01J2219/322—Basic shape of the elements
  • B01J2219/32203—Sheets
  • B01J2219/32255—Other details of the sheets
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/32—Details relating to packing elements in the form of grids or built-up elements for forming a unit of module inside the apparatus for mass or heat transfer
  • B01J2219/322—Basic shape of the elements
  • B01J2219/32203—Sheets
  • B01J2219/32265—Sheets characterised by the orientation of blocks of sheets
  • B01J2219/32272—Sheets characterised by the orientation of blocks of sheets relating to blocks in superimposed layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
  • B01J2219/32—Details relating to packing elements in the form of grids or built-up elements for forming a unit of module inside the apparatus for mass or heat transfer
  • B01J2219/326—Mathematical modelling

Definitions

• the present invention relates to a structured packing for mass transfer and/or heat exchange between a liquid and a gas, wherein the structured packing comprises a multiplicity of sheets with corrugations parallel to one another, the corrugations in the sheets delimiting channels, and wherein adjoining sheets with corrugations are arranged with their channel directions crosswise, and wherein the corrugations of each sheet have a corrugation height H and a corrugation width B.
• Structured packings of this type are generally know per se. In the case of sheets having sine-wave-shaped corrugations, in general a value of around the number ⁇ is taken for the corrugation width whilst a figure of around a value of 1 is taken for the corrugation height. In this context, the unit of ⁇ and the value 1 is in general in cm.
• adjoining sheets with corrugations also termed corrugated sheets
• boundary surfaces being formed at the location where the open sides of two crossing channels cross one another. Gas streams flowing in different directions through channels which cross one another come into contact with one another at said boundary surfaces.
• the pressure drop over a packing as a consequence of flow resistances to which gas streams flowing therethrough are subjected is to a large extent dependent on, on the one hand, the flow resistance to which the gas streams are subjected at the contact surface with the sheets with corrugations and, on the other hand, on the resistance as a consequence of flow effects produced at the boundary surfaces, which are also termed boundary surface effects, such as turbulence.
• boundary surface effects such as turbulence.
• the sheets with corrugations which in practice are arranged vertically, are arranged with the direction of their channels usually at an angle of approximately 30° with respect to the vertical, which angle will, however, not exceed 45° in practice.
• the reason for this is that the flow resistance over the packing becomes too great when the angle of the channel direction with respect to the vertical is (relatively) large.
• the aim of the present invention is to provide an improved structured packing of the type indicated in the preamble.
• the ratio of corrugation height H to corrugation width B satisfies the equation H / B ⁇ 0.75.
• H / B ratio increases, the influence of effects giving rise to flow resistance at the so- called boundary surfaces decreases because the average distance of the gas from said boundary surface is increased at these locations with a larger H / B ratio.
• this reduction in the flow resistance as a consequence of so-called boundary surface effects is offset by an increase in the flow resistance experienced at the contact surface between the corrugated sheets arid the gas streams since the contact surface per channel between the sheet and the gas stream becomes larger when the H / B ratio is increased.
• the sheets with corrugations are arranged essentially vertically.
• one or more of the corrugated sheets are arranged with their channel direction at an angle of at least approximately 45° with respect to the vertical.
• one or more of the corrugated sheets are arranged with their channel direction at an angle of approximately 55° to 65° with respect to the vertical, such as at an angle of approximately 60° with respect to the vertical.
• the pressure drop over the packing according to the invention is lower than is the case with conventional packing.
• the sheets with corrugations are provided with holes at the channel ends adjoining the wall sections. Such holes make it easier for the flowing gas to pass from a channel running in one direction into a channel running in another, crosswise direction.
• such an edge region will preferably extend up to 10-20 cm from the wall, depending on the so-called specific surface area.
• relatively large cylindrical containers are understood to be containers having a diameter of 1 or more.
• such an edge region will extend over a distance of approximately 10 % to 20 % of the width/depth of the container and in the case of a cylindrical container over a distance of approximately 10 % to 20 % of the diameter of said container.
• the holes will have a diameter of at least 2 mm up to, preferably, at most 20 mm, or a flow area equivalent to this in the case of non-circular holes.
• Figure 1 shows, diagrammatically , a triangular corrugation profile, in which a few parameters thereof have been indicated in more detail;
• Figure 2 shows a perspective and diagrammatic view of part of a structured packing according to the invention made up of four layers;
• Figure 3 shows a diagrammatic view, partially in cross- section, of a container according to the invention
• Figure 4 shows diagrammatically, one corrugation with a sine-wave-shaped corrugation profile
• Figure 5 shows a plot of an H / B relationship for a sine- wave-shaped corrugation profile
• Figure 6 shows a highly diagrammatic representation of a test set-up.
• Figure 1 shows, diagrammatically, a triangular corrugation profile having a corrugation height H and a corrugation width B. It will be clear that said corrugation height H and corrugation width B are assignable in an identical manner to the corrugations of the sine-wave-shaped corrugation profile shown in Figure 4.
• FIG. 2 shows, by way of example, in highly diagrammatic form, a structured packing according to the invention consisting of, by way of example, four layers of sheets with corrugations (also termed corrugated sheets), each having a triangular corrugation profile.
• sheet 2 with corrugations delimits a multiplicity of channels extending transversely to the direction of corrugation G.
• the corrugated sheets 3 are identical to the sheets with corrugations 2 except for their orientation.
• the embodiment according to Figure 3 shows a container according to the invention which is provided with a packing 1 according to the invention.
• liquid is distributed over the packing via a spray device 10 at the top. Said liquid flows downwards over the surfaces of the sheets with corrugations in a manner such that a liquid film is formed on the surfaces of the sheets.
• a gas is supplied at the bottom of the packing, which gas flows upwards through the packing in counter-current to the liquid (film). Transfer between the liquid and the gas can take place during the counter-current flow. It is pointed out that the flow of gas and liquid through the packing can optionally also take place in co-current or by transverse flow. With packings according to the invention advantages are also obtained with co-current and transverse current flow.
• the corrugated sheets of packing 1 are arranged vertically with a channel direction K at an angle of essentially greater than 50° with respect to the vertical (however, angles of less than 50° are also usable and offer significant advantages according to the invention) .
• a lower packing 11 is also arranged beneath the upper packing 1.
• the channel direction runs at an angle of approximately 60° with respect to the vertical.
• the channel direction runs at an angle of approximately 45° with respect to the vertical, which angle under certain circumstances can also be smaller than 45° with respect to the vertical, such as, for example, 30°.
• Figure 3 further illustrates what is understood by an edge region adjoining the wall or the wall section of the container.
• said edge region is indicated by R and the magnitude of R will in general be approximately 10-20 cm for containers having a diameter of 1 m and above, whereas for containers having a smaller diameter said R will be approximately 10 % to 20 % of the diameter.
• the corrugated sheets are provided with holes 5 in said so-called edge region, which holes make it easier for the gas to pass from one channel sloping in one direction to a crossing channel, sloping in the other direction, in the edge regions, in order thus to reduce the flow resistance of the packing. It will be advantageous to provide the edge regions of the packing with such holes 5 especially when, according to the invention, relatively large angles are used for the channel direction with respect to the vertical .
• each packing unit 21, 22 consists of a number of vertically arranged sheets with corrugations parallel to one another. As is shown diagrammatically in Figure 6, the sheets with corrugations 21 and 22 of adjacent packing units are positioned perpendicular to one another. In the packing units the channel direction of each sheet is in all cases at an angle of 45° to the vertical.
• the corrugation profiles in this experiment are essentially triangular in shape, with a corrugation height H and a corrugation width B, as is indicated diagrammatically in Figure 1. In other respects use was made of two test set-ups, the specific structural characteristics of which are given in the table below:
• superfacial gas rate U (in m/s) is understood to be the average flow rate of the air with respect to the cross-sectional area of the cylinder, which cross-sectional area is therefore 289.53 cm 2 here.
• the air drawn in from the environment was at a temperature of 20°C and atmospheric pressure. The results of the measurements in this experiment are given in Table II below.
• Experiment II was carried out using the same set-ups I and II as used for Experiment I. The difference in this case is that in Experiment II a water film was also introduced on to the packings by spraying water at the top of the set-up shown in Figure 6.
• the quantity of water W is expressed here in kg/s/m 2 , that is to say in kg water per second distributed over a cross-sectional area of the cylindrical container, which in this case is approximately 289.5 cm 2 , as has been indicated above.
• the superficial gas rate U at which a pressure drop per metre packing of 800 Pa/m is obtained was determined for three quantities of water W per set-up. The results obtained in this experiment are shown in Table III.

Landscapes

• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)
• Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=19764928

Family Applications (1)

Country Status (7)

Families Citing this family (8)

Family Cites Families (6)

• 1997
  • 1997-05-06 NL NL1005990A patent/NL1005990C2/nl not_active IP Right Cessation
• 1998
  • 1998-05-05 JP JP54793698A patent/JP2001523163A/ja active Pending
  • 1998-05-05 CN CN 98804897 patent/CN1255194A/zh active Pending
  • 1998-05-05 BR BR9809220-0A patent/BR9809220A/pt unknown
  • 1998-05-05 AU AU74568/98A patent/AU7456898A/en not_active Abandoned
  • 1998-05-05 EP EP98921912A patent/EP0980505A1/de not_active Withdrawn
  • 1998-05-05 WO PCT/NL1998/000247 patent/WO1998050752A1/en not_active Application Discontinuation

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events