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
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
  • B01D3/14—Fractional distillation or use of a fractionation or rectification column
  • B01D3/16—Fractionating columns in which vapour bubbles through liquid
  • B01D3/18—Fractionating columns in which vapour bubbles through liquid with horizontal bubble plates
  • B01D3/20—Bubble caps; Risers for vapour; Discharge pipes for liquid

Definitions

• the present invention relates to chemical process towers and, more particularly, but not by way of limitation, to a downcomer-tray assembly for maximizing
• Distillation columns are utilized to separate selected components from a multi component stream. Successful fractionation in the column is dependent upon intimate contact between liquid and vapor phases. Some columns use vapor and liquid
• the above-referenced trays are generally installed on support rings within the tower and have a solid tray or deck with a plurality of apertures in an "active" area. Liquid is directed onto the tray by means of a vertical channel from the tray above.
• the liquid moves across the active area and
• Vapor ascends through the apertures in the trays and contacts the
• the liquid moving across the tray The liquid and vapor mix in the active area and fractionation occurs. It is the active area of the tray that is of critical concern.
• the maximum fractionation capacity of the tray generally increases with
• the liquid is the driving force to effect mass transfer. Said concentration-difference can be
• Liquid entrainment is, in one sense, a dynamic flow condition.
• High velocity vapor flow can suspend descending liquid droplets and prevent their
• process column is allowed to by-pass the active area of a tray.
• Efficiency of the active area in a tray is also influenced by the flow of
• the flow of the liquid is not typically a flow characteristic that provides
• the present invention relates to the chemical process tower downcomer
• one aspect of the present invention comprises a
• the downcomer disposed above a chemical process tower tray.
• the downcomer. is formed
• the downcomer outlet is formed by the lower edge of the wall
• the lower edge of the wall region is closer to the wall of the process tower at
• a discharge plate is disposed
• the apertures are formed of such a size and spacing
• the wall region includes semi-conical walls that
• the wall region comprises a smooth curved edge.
• the lower edge of the wall region comprises multiple straight lines connected
• the present invention comprises an improved
• the improvement comprising the steps of supporting the tray in the process column with a tray support located below a tray support area, forming a downcomer outlet having a
• FIG. 1 is a perspective view of a packed column with various sections cut
• FIG. 2 is an enlarged, fragmentary, perspective view of the downcomer-
• FIG. 3 is an enlarged, fragmentary, perspective view of the downcomer
• FIG. 4 is a diagrammatic, side-elevational, cross-sectional view of the
• FIG. 5 A is an enlarged, fragmentary top view of one embodiment of the
• FIG. 5B is an enlarged, fragmentary top view of another embodiment of
• FIG. 5 C is an enlarged, fragmentary top view of another embodiment of
• FIG. 6 is a top plan, diagrammatic view of a prior art tray illustrating the
• FIG. 7A is an enlarged, fragmentary top view of an embodiment of a
• FIG. 7B is an enlarged, fragmentary top view of another embodiment of
• FIG. 7C is an enlarged, fragmentary top view of another embodiment of
• FIG. 8 is a top plan, diagrammatic view of a tray illustrating the liquid
• FIG. 1 there is shown a fragmentary, perspective view
• FIG. 1 comprises a cylindrical tower 12 having packing beds 38 and 39, and
• the tower 12 of the column 10 includes a skirt 28 for the support of
• a plurality of manways 16 are constructed for facilitating access to the
• a stream vapor feed line or reboiler return line 32 is
• a vapor outlet or overhead line 26 is
• a reflex return line 34 is provided in an upper portion of the tower 12.
• the liquid 13 is depleted of some material which is gained by the vapor 15 as they
• the vapor 15 is depleted of some material which is gained by the liquid 13.
• upper packing bed 38 are shown for the purpose of illustration and include a liquid collector 40 disposed beneath a support grid 41 in support of the upper structured packing
• a liquid distributor 42 adapted for redistributing liquid 13, is likewise disposed
• a second type of distributor 42a is shown below the cut-line and disposed
• FIGS. 2 and 3 there are shown two fragmentary
• FIG. 1 perspective views of the downcomer-tray assembly 100 in FIG. 1 taken from opposite
• first tray 110 connected to a first downcomer 120, and a second tray 130
• the trays 110 and 130 are generally planer
• the outlet weirs 112 and 132 are
• the downcomers 120 and 140 have semi-record data. Still referring to FIGS. 2 and 3, the downcomers 120 and 140 have semi-record data.
• 121 and 141 of the downcomers 120 and 140 are preferably formed from flat plates 121a-
• side walls may be modified with more downcomer sections or with fewer downcomer
• Downcomer outlets 122 and 142 are formed between the bottom of the walls 121 and 141 and the inner surface of the tower
• the downcomer outlets 122 and 142 are positioned directly
• the tray 130 has an inlet weir 133
• the inlet weir 133 has a vertical height that extends above the position of
• the lower portion of the downcomer 120 is supported by
• the tray 130 includes a plurality of venting
• the venting chambers 135 have a
• the liquid 13 exits the downcomer 120 through the outlet 122 and accumulates on the
• chambers 135 imparts a horizontal flow vector to the liquid 13 spilling over the inlet weir
• the tray 130 engages vapor 15 ascending through the active area 131.
• the froth or "foam" is a region of aeration
• the froth 61 extends with a relatively
• the length of the active area 131 of the tray 130 is governed by the distance between the
• FIG. 5 A there is shown a top view of the tray 110 and
• the downcomer 120 illustrated in FIGS. 2, 3, and 4. The downcomer 120 is separated from
• the downcomer 120 is a chordal downcomer characterized by the
• FIG. 5B there is illustrated a top view of another
• the downcomer 120' is a swept downcomer (or multi-
• chordal downcomer and is characterized by the outlet weir 112' having many, segments.
• the outlet weir 112' has first and second segments 112a' and 112b' that are positioned in
• FIG. 5C there is shown a top of view of yet another
• the downcomer 120 is defined by the outlet weir
• the outlet weir 112" is characterized by arcuate section that is semi-circular
• outlet 122 is narrower than the upper region of the downcomer 120, causing a build up
• a pool of liquid 13 from the downcomer 120 is created between the inlet weir 133
• outlet 122 will be immersed in the pool of liquid accumulated between the inlet
• the tray 130 has a support ring
• the tray 130 also has a tray inlet area 138 located
• outlet 122 first contacts the tray 130. Due to the flow of liquid 13 from the downcomer
• the tray inlet area 138 of the tray 130 cannot readily be used as an active area
• the tray inlet area 138 is substantially within the
• tray 130 substantially within the support ring region 137, the area of the tray 130
• downcomer outlet 122 and corresponding tray inlet area 138 of the tray 130 can vary
• tray active area 131 inwardly of the tray support ring region
• FIG. 6 there is shown a flow diagram across a
• the prior art tray 950 is illustrated herein as a round tray having a first
• a second downcomer 954 carries
• FIG. 7A there is shown a top view of an embodiment
• Downcomer 174 is formed by semi-conical wall 176 and the inside surface of wall 11 of
• Semi-conical wall 176 is formed from plates 176a-e, respectively, that are
• the downcomer outlet 180 is
• downcomer outlet 180 is characterized
• outlet portions 180a-e respectively, with the size of outlet portions 180a-e increasing
• liquid 13 is therefore allowed to flow from and through outlet portions 180a, 180b, 180d
• 176a-b and 176d-e respectively, is positioned further away from the inner surface of wall
• 11 as lower edge 178 is formed from plate 176c to plate 176a and from plate 176c to
• outlet 180 will flow onto tray inlet area 152 and over the inlet weir 146 (see FIG. 8) of
• FIG. 7B there is shown a top view of another
• Downcomer 188 is separated from the active area 171 of upper tray 170 by the outlet weir
• Downcomer 188 is formed by semi-conical wall 190 and the inside surface of wall
• Semi-conical wall 190 is formed from plates 190a-h, respectively, that
• the downcomer outlet 194 is
• outlet portions 194a-h characterized by outlet portions 194a-h, respectively, with the size of outlet portions
• tray 170 will flow across tray 216 as uniform flow, as illustrated by a plurality of
• FIG. 7C there is shown a top view of an additional item
• Downcomer 198 is separated from the active area 171 of tray 170 by the outlet weir 172.
• Downcomer 198 is formed by semi-conical wall 200 and the inside surface of wall 11 or
• Semi-conical wall 200 is formed from plates 200a-f, respectively, that are
• the downcomer outlet 204 is
• Discharge plate 202 is formed by discharge apertures 204a-f formed in discharge plate 202. Discharge plate 202
• downcomer outlet 204 is characterized by
• apertures 204a and 204b than from discharge aperture 204c and also apertures 204e and
• tray 216 in a uniform manner, effectively approximating flow in a generally rectangular
• FIG. 8 there is shown a flow diagram across a tray 216
• arrows 208 illustrate the uniform flow of liquid across tray 216 which essentially

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Organic Chemistry (AREA)
• Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
• Physical Or Chemical Processes And Apparatus (AREA)
• Extraction Or Liquid Replacement (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=25206548

Family Applications (1)

Country Status (12)

Families Citing this family (5)

Family Cites Families (3)

• 1998
  • 1998-02-27 EP EP98907678A patent/EP0964732A1/de not_active Withdrawn
  • 1998-02-27 KR KR1019997007963A patent/KR20000075884A/ko not_active Application Discontinuation
  • 1998-02-27 CA CA002278756A patent/CA2278756A1/en not_active Abandoned
  • 1998-02-27 BR BR9807643-4A patent/BR9807643A/pt unknown
  • 1998-02-27 JP JP53861498A patent/JP2001513701A/ja active Pending
  • 1998-02-27 WO PCT/US1998/003920 patent/WO1998039077A1/en not_active Application Discontinuation
  • 1998-02-27 AU AU63429/98A patent/AU716737B2/en not_active Ceased
  • 1998-03-02 ZA ZA981737A patent/ZA981737B/xx unknown
  • 1998-03-03 ID IDP980316A patent/ID20927A/id unknown
  • 1998-03-03 AR ARP980100936A patent/AR011917A1/es unknown
  • 1998-03-03 CO CO98011516A patent/CO4761079A1/es unknown
• 1999
  • 1999-01-30 TW TW087115108A patent/TW438616B/zh active

Non-Patent Citations (1)

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