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Depending on the flow rates, column con-figuration and general mechanical prefer-ences, there are several ways to achievegood liquid distribution.

Deck Type Distributors

Deck style distributors are clamped on anannular ring that is seal welded to thetower wall. For revamp applications oftrayed columns, most often an existingtray ring is utilized and seal welded seg-ments are added as needed. In the casewhere welding is not permitted, bolt-insegments are available by special requestbut provide a less reliable liquid seal.Leakage from and around bolt-in supportring segments can be a significant portionof the total liquid flow, resulting in poordistribution quality. In this case, a troughor channel type distributor should beconsidered.

Channel Type Distributors

The center channel is designed as a struc-tural member allowing the distributors torest on a support ring and span columnsup to 20 ft [6 m] without the need foradditional beams.

Locating the distributor on existing sup-port ring in revamp work often makes iteasy to determine the tower layout.Supporting a channel type distributor onan annular ring generally requires a morecomplex design and construction in orderto provide drip points at the properproximity to the tower wall. Thisincreased complexity can be avoided bysupporting channel type distributor withthe center channel resting on a seat andthe channel troughs hung from beams ora ring above. Both beam and ring sup-ported channel distributors can bedesigned to accommodate uplift condi-tions.The center channel of a channeltype distributor provides cross flowcapacity between troughs, to enable liquidhead equalization.

The addition of covers or hats over thegas riser area provides the ability to turnthe device into a redistributor for usebetween packed beds. This design is especially useful when tower elevation istight and minimal height for redistributionis required.

Trough Type Distributors

Trough type distributors are usually hungfrom beams. When used in conjunctionwith structured packings, in special cir-cumstances, the trough distributor may besupported from an integral support sys-tem resting directly on the packing.Trough type distributors are easilyinstalled and leveled, do not require gas-kets and have no annular ring below tointerfere with the distribution pattern.

Each trough is fed a metered amount ofliquid from one or more parting boxes.Because there is no flow communicationbetween troughs, the performance of theparting box is critical. Koch-Glitsch’syears of experience ensure parting boxdesigns for proper flow metering.

When used between packed beds for re-distribution, a trough type distributorrequires the use of a collector to catchthe liquid from the bed above. The use ofa separate collector provides completecross mixing of the liquid before redistri-bution and also allows mixing of feedstreams with the internal column liquid.A separate collector requires more column height than a channel type redistributor.

Standard connection to the towerwall is by bolting to clips. As anoption, the distributor can be sus-pended from clips or a ring trappedbetween body flanges. Setting thedistributor on an annular ring is notrecommended.

All joints in multi-piece pans are gasketed.

The standard design for a Model 107 redistributor includes gas riser covers and a weld-on wallwiper.

• Orifice strainers• Expandable and gasketed wall

wiper (Model 107)• Suspended mounting• Raised tube metering for high

turndown or fouling concern• Anti-migration bars

Model 106 INTALOX® Pan Distributor (Model 107 Redistributor)

Liquid Distributors

� Diameters 6 - 36 in. [150 - 900 mm]� Orifices in pan floor� Liquid rates above 2 gpm/ft2 [5 m3/m2 h]� Limited fouling resistance

Orifices in the pan bottom are arranged to provideoptimum distribution quality, with gas risers posi-tioned between the drip points. Small diameter pansmay not require gas risers as gas passage is providedin the gap between the pan and the vessel wall.

When used for higher flow rates, this distributor willhave large orifices that will tend not to foul. Orificestrainer caps, raised orifices or a Model 136/137should be considered for low flow rates in combina-tion with fouling concerns. For rates lower than 2gpm/ft2 [5 m3/m2 h] a Model 136/137 should be con-sidered first. This distributor has a standard turn-down range of 2 : 1 and can be leveled during instal-lation.

In towers less than 24 in. [600 mm] diameter, one-piece construction, for installation through a bodyflange, is standard. A special multi-piece constructionis available upon request.

Construction Details Design Options

Copyright 2003 Koch-Glitsch, LP. All rights reserved. INTALOX is a registered trademark of Koch-Glitsch, LP and is registered in the US and various countries worldwide.

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The Model 116/117 distributor isclamped onto an annular ring that isseal-welded to the tower wall, withclamps provided. Hence, distributorlevelness is determined by the ringlevelness. Design of the Model116/117 distributor takes intoaccount support ring levelness tolerances within ASME code or as otherwise specified. All joints aregasketed.

For redistribution between beds, aseparate liquid collector is notrequired. The standard design fora Model 117 redistributorincludes gas riser covers tocollect liquid.

• Orifice strainers• Anti-migration bars in gas risers• Raised tube metering for high

turndown or fouling concern• Construction for mounting

between flanges

Design Options� Diameters 36 - 240 in. [150 - 6000 mm]� Liquid rates between 4 - 80 gpm/ft2

[10 - 200 m3/m2 h]� Orifices in deck

Orifices in the deck are arranged to provide opti-mum distribution quality. The deck-type construc-tion provides good liquid cross-flow between gas ris-ers that are positioned between drip points.

Because this deck style distributor is normallydesigned to be used to handle higher liquid flowrates, the orifices are usually large and do not tend to foul. For liquid rates below 8 gpm/ft2

[20 m3/m2 h], use of a channel or trough style distributor is generally recommended.

The standard turndown range is 2 : 1.

The Model 126/127 distributor restson an annular ring or is suspendedfrom a ring or beams. All joints aregasketed.

The standard design for a Model 127redistributor includes a weld-on wallwiper and bolted gas riser covers,used to collect and redistribute liquid. The redistributor design usesless column height than a separatecollector/distributor layout and isvaluable where space is limited andtotal cross mixing of liquid betweenbeds is not critical.

• Model 127 cross-mixing capability (extent is dependent on diameter and rate)

• Orifice strainers• Leveling screws• Expandable and gasketed wall

wiper (small diameter Model 127)

� Diameters greater than 36 in. [900 mm]� Liquid rates between 2 - 16 gpm/ft2

[5 - 40 m3/m2 h]� Orifices in channel base� Limited fouling resistance� Structural center channel provides flow

equalization

Orifices in the base of the channels are positionedto optimize distribution quality. Vapor passage isprovided by the space between the channels. Rateslower than 2 gpm/ft2 [5 m3/m2 h] can be accommo-dated but a Model 136 sidewall orifice distributorshould be considered first. For systems with liquidrates in excess of 12 gpm/ft2 [30 m3/m2 h] a Model116 deck style distributor should be considered.

The channel-type construction allows easy liquidsealing and distributor leveling, which is essential inlarge diameter towers. Because this distributor normally handles intermediate liquid flow rates,the orifices are usually large enough to allow low to moderate fouling resistance.

The standard turndown range is 2 : 1.

Model 116 INTALOX® Deck Distributor (Model 117 Redistributor)

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Model 126 INTALOX® Channel Distributor with Bottom Orifices ( Model 127 Redistributor)




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The Model 136/137 distributor areusually constructed as pans for diam-eters below 30 in. [750 mm] and aschannels for diameters above 30 in.[750 mm].

The Model 136/137 distributor restson an annular ring or is suspendedfrom beams or clips. All joints aregasketed.

The standard design for the Model137 redistributor includes a weld-onwall wiper and bolted gas riser cov-ers to collect and redistribute liquid.The redistributor design uses lesscolumn height than a separate collec-tor/distributor layout and is valuablewhere space is limited and total crossmixing of liquid between beds is notcritical.

• Cross-mixing capability (extent is dependent on diameter and rate)

• Orifice strainers• Leveling screws• Multi-level orifices• Expandable and gasketed wall

wiper (small diameter Model 137)• Removable drip tubes

� Diameters greater than 10 in. [250 mm]� Liquid rates between 0.3 - 12 gpm/ft2

[0.75 - 30 m3/m2 h]� Structural center channel provides flow

equalization� Liquid overflow protection� Side-wall orifices � Fouling resistant

Orifices in the sidewalls of the channels are positionedto optimize distribution quality. Vapor passage is pro-vided by the space between the troughs.

The fouling resistance of this distributor is higher thanthat of deck-type distributors because it features adebris collection zone below the sidewall orifices.Thecenter channel of the distributor provides structuralsupport as well as equalization of liquid betweentroughs.

The liquid from each drip point is conducted into thelower vapor velocity region below the distributortroughs. This results in low entrainment levels. Inaddition, overflow holes are provided at each conduc-tor tube to ensure that if the maximum flow range ofthe distributor is exceeded, the liquid will be con-ducted to the packing in a controlled manner ratherthan to randomly spill over the troughs.

The standard turndown for a single sidewall orifice is2 : 1. Using multiple orifices at two or more levels ofthe same discharge conductor can extend the turn-down range. Turndown ratios up to 10 : 1 are achiev-able. The flow variation will be higher throughout allor part of the operating range with multi-level ori-fices.


Model 136 INTALOX® Channel Distributor with Drip Tubes (Model 137 Redistributor)


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Model 186 INTALOX® Trough Distributor with Drip Tubes

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As the standard, the Model 186 dis-tributor is suspended from beams.By special request, and within a limit-ed range of diameters, provisions canbe made for the distributor to reston an existing support ring.

Model 186 troughs are continuousacross the column diameter and arefed with one or more parting boxes.There are no joints to seal, therefore,no gaskets are required.

For redistribution between packedbeds, a separate liquid collector isrequired. The use of a separate liquidcollector provides total cross mixingof the liquid between beds.

• Orifice strainers• Multi-level orifices• Metering Boxes• Mounted on support ring or

supported by Model 883 bed limiter/support

� Diameters greater than 30 in. [760 mm]� Liquid rates between 0.3 - 10 gpm/ft2

[0.75 - 25 m3/m2 h]� Sidewall orifice� Liquid overflow protection� Fouling resistant� Low entrainment

Orifices in the sidewalls of the troughs are posi-tioned to optimize distribution quality. Vapor passage is provided by the space between thetroughs. Special designs can handle liquid ratesabove or below the above stated range.

The liquid from each drip point is conducted intothe lower vapor velocity region below the distribu-tor troughs. This results in low entrainment levels.In addition, overflow holes are provided at eachconductor tube to ensure that if the maximumflow range of the distributor is exceeded, the liquidwill be conducted to the packing in a controlledmanner rather than to randomly spill over thetroughs.

The standard turndown for a single sidewall orificeis 2 : 1. Using multi-level orifices at each dischargeconductor can extend the turndown range up to10 : 1. The flow variation will be higher through-out all or part of the operating range with multi-level orifices.



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