®

IntroductionChemical processors and petroleum refiners around the world are familiarwith the name INTALOX®. INTALOX is a "family" of tower packingdesigns that sets the standard wherever process towers are equipped withrandom or structured packing to effect heat or mass transfer. At the heartof these designs is the INTALOX® Metal Tower Packing or IMTP® HighPerformance Random Packing family. INTALOX Metal Tower Packing is thefirst random packing designed especially for use in distillation operations.The advantages realized in distillation have been abundantly applied inabsorption, stripping, liquid-liquid extraction and direct contact heat trans-fer operations as well. Since its introduction in the late 1970’s, IMTP pack-ing has been successfully used in thousands of mass transfer towers withdiameters ranging from 6 inches to 40 feet [150 mm–12m]. Simultaneously,a line of high performance tower internals was developed to ensure themaximum performance of each packed tower is achieved. Koch-Glitschengineers have extensive experience applying these technologies to a vari-ety of processes, providing the best solution for each situation.

This booklet provides information for quick sizing of packed columns usingINTALOX Metal Tower Packing. The following charts provide informationfor hydraulic ratings and relative packing efficiencies in terms of HETP basedon a standard hydrocarbon test system as well as KGa values for the absorp-tion of CO2. In addition, Koch-Glitsch offers the hydraulic rating program,KG-TOWER™ Software, that may be downloaded from the website.www.koch-glitsch.com

Koch-Glitsch recognizes that not all applications, are demanding enough torequire the use of IMTP high performance random packing. For those appli-cations, Koch-Glitsch offers a wide variety of additional tower packings suchas β-ETA RING®, CASCADE MINI-RING®, HY-PAK®, FLEXIRING®

and Raschig Ring Random Packings. For information on these packings pleaserefer to brochure KGMRP-1.

Emergency Delivery

Koch-Glitsch has IMTP as well as other random packings – metal or plastic– to provide optimum performance whatever your application. In commonmaterials, most packings are in stock for immediate shipment to get youback on line. For emergencies call the Hotline of your nearest Koch-Glitschoffice.

In the US call the Hotline 1-888-KOCH-911In Europe call 0044 1782 744 561

or your local Koch-Glitsch office

1

IMTP packing is applicable in as broad a range of services as any mass transfer device. It is heavily used in distillation towers: from deep vacuum towers, wherelow pressure drop is crucial to high-pressure towers,where capacity easily surpasses that of conventional trays. Many absorption and stripping towers, especially those aiming for high capacity or close approach to equilibrium, rely on IMTP packing.The low pressure drop, high specific heat-transfer coefficient, as well as the fouling resistance of IMTPpacking contributes to its success in heat transfer tow-ers, such as olefin plant quench columns.

In a distillation system, uniform liquid and vapor distri-bution causes the HETP to be nearly independent of liquid and vapor rates. However, at higher vapor ratesthe packing exhibits a region of improved efficiency (lowHETP) where high vapor turbulence influences the liq-uid surfaces and improves the mass transfer.

Koch-Glitsch defines two packing properties from a per-formance curve:

1. The System Base HETP is the constant HETP value produced by uniform distribution.

2. The Maximum Efficient Capacity is at the highest vapor rate where the packing maintains the System Base HETP.

Note: Efficient Capacity is not the same as the hydrauliccapacity or flood point. Koch-Glitsch rates high performancepackings by both, Efficient Capacity and Hydraulic Flood.

The System Base HETP concept raises important questions:

• What is the System Base HETP of a packing in a given system? (See page 4).

• How much does liquid distribution quality affect HETP? (See page 5)

• Which liquid distributors should be chosen to make a tower perform near its System Base HETP? (Consult the Tower Internals Guide KGMTIG-1.)

2

IMTP® High Performance Random Packing

Flood Point

IMTP Packing Performance UnderUniform Liquid and Vapor Distribution

Vapor Rate

HET

P (H

eigh

t Eq

uiva

lent

to

a T

heor

etic

al P

late

)

Maximum Efficient Capacity

System Base HETP

Material of Construction

INTALOX Metal Tower Packings are offered in variousmaterials of construction.

• Carbon Steel• Stainless Steels, including Austenitic, Ferritic,

Martensitic; types 409/410/430, 304 and 316 are readily available

• Duplex Stainless Steel• Nickel and nickel alloys• Aluminum• Copper and copper alloys• Titanium and zirconium

Packing Capacity

Capacity Correlation

The Maximum Efficient Capacity of IMTP packing in a non-foaming system can be estimated as:

Nomenclature and DefinitionsL : Liquid mass rateG : Gas mass rateρL : Liquid density

ρG : Gas density

V : Superficial gas velocity, ft/s or m/s

X = Flow parameter

Cs = V Capacity Factor, ft/s or m/s

Fs = V F-Factor, ft/s • (lb/ft3)1/2 or m/s • (kg/m3)1/2

LG

ρG

ρL

ρG

ρG

ρL – ρG

Data Range

Koch-Glitsch routinely designs towers up to 90% MaximumEfficient Capacity. This limit leaves an estimated 11% turn-up before the packing loses its design efficiency.

3 < σ < 73

0.07 < µ < 3.0

Csc = Co 1.03 for > 1.03

IMTP #15 IMTP #25 IMTP #40 IMTP #50 IMTP #60

IMTP #70

3

If µ > 0.07, use, µ = 0.07

Correlation Limits

σ : Surface tension, dyne/cm

µ : Liquid viscosity, cp

σ20

µ0.2

0.16 -0.11

Maximum Efficient Capacity, Csc = Co

σ20

µ0.2

0.16 -0.11

The efficiency of packing in most distillation towers is expressed as HETP or height equivalent to a theoret-ical plate.

The mass transfer efficiency of all mass transfer devicesis system properties dependent. System properties thataffect the efficiency are liquid viscosity and surface ten-sion. The efficiency of a packed system also depends onthe uniformity of liquid and vapor distribution.

The concept of System Base HETP assumes that a spe-cific separation receives uniform liquid and vapor distribution. This concept is useful because it isolatesthe system’s effect on HETP away from the distributionconsiderations.

As a first approach in projecting HETP values, Koch-Glitsch has developed a correlation for estimating HETPfrom the system properties. It is desirable to confirmthe projected HETP values with test data in columnshaving uniform vapor and liquid distribution in the samesystem or a system having very similar properties. Koch-Glitsch has an extensive bank of operating data from awide variety of systems and can provide reference datato confirm final HETP values upon request.

The efficiency correlation applies to systems which:A) are non-aqueous B) are non-reacting and non-ionizingC) have low to moderate relative volatility

(less than three)

In these systems, the System Base HETP of IMTP pack-ing for distillation and reboiled stripping services can be estimated by:

The packing efficiency in other services or other sys-tems must be estimated by other methods.

Non-uniform liquid and vapor distribution will causeactual HETP values to be substantially greater than theSystem Base HETP value. However, commercial towerswith proper liquid and vapor distribution consistentlyapproach the System Base HETP within 13%. For thisreason,Koch-Glitsch designs often use HETP values 13%above the System Base HETP.

What represents proper liquid distribution for a com-mercial tower? In towers requiring few theoreticalstages, traditional distributors can approach the SystemBase HETP value. Conversely, in towers requiring manytheoretical stages Koch-Glitsch INTALOX distributorsare required to approach the System Base HETP value.

Packing Efficiency

4

System Base = A for µ < 0.4 cpσ20

-0.16

System Base = B for µ > 0.4 cpσ20

µ0.2

-0.19 0.21

Relative Volatility < 3If σ > 27, use, σ = 27

σ : Surface tension, dyne/cm

µ : Liquid viscosity, cp

Values of A and BIMTP Packing Size

A-mm

A-in.

B-mm

B-in.

No.15 No. 25 No. 40 No. 50 No. 60 No. 70

272 330 401 526 616 758

10.7 13.0 15.8 20.7 24.2 29.9

296 366 439 579 678 827

11.7 14.4 17.3 22.8 26.7 32.6

Data RangeCorrelation Limits

2.0 < σ < 26.6

0.06 < µ < 0.83

[1.78]µ

Koch-Glitsch INTALOX® Packed Tower Systems arepredictable and reliable separation columns containingwell-matched high performance packing and state-of-theart liquid and vapor distributors. Koch-Glitsch’s globalexperience is second to none and includes thousands ofcolumns in distillation, absorption, stripping, liquid-liquidextraction and heat transfer applications.

The combination of INTALOX high performance internalsand IMTP high performance random packing provides thehighest random packing performance available in theindustry.

Koch-Glitsch has developed a series of liquid distributorswith attributes to maximize packed tower performance.These attributes are well understood and have beenincorporated into INTALOX high performance distribu-tors. Koch-Glitsch introduced a distributor rating systemfor quantifying distribution quality and performance.Distribution uniformity is rated as a percentage, where100% indicates ideal uniform distribution. A low percent-age rating indicates a high variation of liquid flow over thecross sectional area of the tower. In addition, the distrib-utor must provide a sufficient gas passage area to avoid ahigh pressure drop or liquid entrainment.

INTALOX distributors aim towards 100% distributionquality by applying the following criteria:A) Drip points are preferable on a uniform triangular

pattern, or alternatively on a square patternB) Drip points are uninterrupted by gas chimneys or

mechanical supports C) Drip points are properly spaced to the vessel wallD) Equal liquid flow from each drip point

The significance of the Koch-Glitsch distribution qualityrating system is the accurate prediction of tower performance.

INTALOX distributors are applied in:• Distillation services with high stage counts per bed• Distillation services with low relative volatility• High purity product distillation services• Distillation services operating near the minimum

reflux or close to a pinch point• Absorption and stripping applications with close

approach to equilibrium• Heat transfer services with close approach

temperatures

A tower containing deep beds of IMTP high efficiency ran-dom packing, designed to achieve many theoretical stagesor transfer units, is very sensitive to liquid distributionquality.

Feed devices are critical to the performance of the liquid distributor and the packed column. Depending onthe specific service, Koch-Glitsch offers a wide range ofINTALOX liquid, vapor, mixed phase and flashing feeddevices.

• INTALOX liquid phase feed pipes are designed to prevent excessive liquid velocity in the distributor to minimize liquid gradients and momentum effects.

• INTALOX vapor phase feed devices are designed to reduce the kinetic energy of the vapor feed before entering the packed bed.

• INTALOX mixed phase feed devices are designed to provide sufficient disengagement of vapor from the liquid prior to feeding the distributor.

• INTALOX suppressed flashing feed devices are designed to avoid vaporization inside the pipe systemand to provide sufficient disengagement of vapor fromthe liquid prior to feeding the distributor.

5

INTALOX® Packed Tower Systems

Stages Per Bed WithSystem Base HETP

20

16

12

8

4

10 20 30 40 50 60 70 80 100900

The effect of liquid distribution quality on towerperformance is shown by these actual results:

Distribution Quality (%)

Act

ual S

tag

es P

er B

ed o

f P

acki

ng

2

4

6

8

10

12

14

16

18

20

0

The effect of liquid distribution quality on tower performance is illustrated below:

Stages per Bed withSystem Base HETP

Distribution Quality (%)

Act

ual s

tage

s pe

r be

d

20

16

12

8

6

* for stainless steel with standard material thickness

Vapor distribution is an important part of INTALOXPacked Tower Systems. A tower with poor vapor distri-bution will experience an unequal liquid-to-vapor ratioover the tower cross sectional area, resulting in a reduc-tion of tower performance. Koch-Glitsch can supply a variety of vapor distributors to ensure that the high effi-ciency packing meets its separation performance objec-tives.

For more detailed information and descriptions regardingKoch-Glitsch INTALOX high performance distributors aswell as all other tower internals, please refer to ourbrochure KGMTIG-1.

Koch-Glitsch goes a step further by offering single suppli-er/installer benefits of turnkey solutions. At your request,the Koch-Glitsch Field Service team is always available toprovide faster, safer revamps with minimum down time.

IMTP® Packing SizeNominal Size 15 25 40 50 60 70

mm 15 25 40 50 60 70inch 5/8 1 11/2 2 23/8 23/4

Void Fraction % 96 97 98 98 99 98

Bulk weight* kg/m3 283 224 153 166 137 141lb/ft3 17.7 14.0 9.6 10.3 8.6 8.8

IMTP® Packing Characteristics

HETP IMTPSystem: i-octane/toluene at 740 torrDiameter: 15.2 inches [386mm]Packed Depth: 10 feet [3.05m]Total Reflux Operation

IMTP #70

IMTP #60

IMTP #50

IMTP #40

IMTP #25

IMTP #15

HE

TP,

inc

hes

HE

TP,

mm

Fs, ft/s (lb/ft )3 1/2•

Fs, m/s (kg/m )• 3 1/2

Cs, ft/sec

IMTP® Packing Efficiency

IMTP® Packing Performance

7

IMTP #25

IMTP #40

IMTP #50

IMTP #60

IMTP #70

K a

, lb-

mol

/(h

ft a

tm)

•3 •

G

K a

, kg-

mol

/(h

m a

tm)

•3 •

G

Liquid Load, gpm/ft2

Liquid Load, m /(m h)3 2•

KGa IMTPCONDITIONS:Liquid Concentrations: 4% NaOHConversion to Carbonate: 25%Inlet Gas Concentration: 1% CO2

Temperature: 75 ºF [24 ºC]Gas rate: 900 lb /(ft hr) [1.22 kg/(m s)]

Tower Diameter: 30in [0.76m]Bed Height: 10ft [3.05m]

2 2

∆p/Z

(in

wc/

ft)

Liquid LoadingTop Curve to Bottomgpm/ft m /m h2 3 2

5040302010

40

1229873492410

0

System Air-Water, AmbientTower: 30in. Diameter

IMTP #25

∆p, i

n w

c/ft

∆p, m

bar/m

Fs, m/s (kg/m )• 3 1/2

Fs, ft/s (lb/ft )•

3 1/2

∆p, i

n w

c/ft

Liquid LoadingTop Curve to Bottomgpm/ft m /m h2 3 2

20181510

40

4944372410

0

System Air-Water, AmbientTower: 30in. Diameter

IMTP #15

∆p, m

bar/m

Fs, m/s (kg/m )• 3 1/2

Fs, ft/s (lb/ft )•

3 1/2

8

∆p/Z

(in

wc/

ft)

Liquid LoadingTop Curve to Bottomgpm/ft m /m h2 3 2

605040302010

40

147122

9873492410

0

System Air-Water, AmbientTower: 30in. Diameter

IMTP #40

∆p/Z

(in

wc/

ft)∆p

, in

wc/

ft

∆p, m

bar/m

Fs, m/s (kg/m )• 3 1/2

Fs, ft/s (lb/ft )•

3 1/2

∆p/Z

(in

wc/

ft)

Liquid LoadingTop Curve to Bottomgpm/ft m /m h2 3 2

605040302010

40

147122

9873492410

0

System Air-Water, AmbientTower: 30in. Diameter

IMTP #50

∆p/Z

(in

wc/

ft)∆p

, in

wc/

ft

∆p, m

bar/m

Fs, m/s (kg/m )• 3 1/2

Fs, ft/s (lb/ft )•

3 1/2

Liquid LoadingTop Curve to Bottomgpm/ft m /m h2 3 2

605040302010

40

147122

9873492410

0System Air-Water, AmbientTower: 29.5in. Diameter

IMTP #60

∆p/Z

(in

wc/

ft)

∆p/Z

(in

wc/

ft)∆p

, in

wc/

ft

∆p, m

bar/m

Fs, m/s (kg/m )• 3 1/2

Fs, ft/s (lb/ft )•

3 1/2

Liquid LoadingTop Curve to Bottomgpm/ft m /m h2 3 2

605040302010

40

147122

9873492410

0System Air-Water, AmbientTower: 30in. Diameter

IMTP #70

∆p/Z

(in

wc/

ft)

∆p/Z

(in

wc/

ft)∆p

, in

wc/

ft

∆p, m

bar/m

Fs, m/s (kg/m )• 3 1/2

Fs, ft/s (lb/ft )•

3 1/2

Applications

Purified Gas

Acid Gas

Absorber Regenerator

Feed Gas

IMTP tower packing has been used in a wide range ofapplications from very low liquid rate services, such asDMT purification and glycol separation, to high liquid rateapplications, such as hot carbonate absorbers and demeth-anizers. IMTP tower packing’s lower pressure drop, com-bined with high mass transfer efficiency, provides superiorperformance in low liquid rate vacuum systems.

The low pressure drop provided by IMTP tower packingmakes it a good choice for foaming systems. The presenceof foam in a packed bed results in a significant pressuredrop increase.The foam represents a very low density liq-uid phase that significantly reduces the void fraction andcapacity within the packed bed. High pressure drop

increases the amount of foam generation due to theresistance of the vapor on the liquid phase. Therefore, itis desirable to design the packed bed with low pressuredrop in foaming systems. IMTP tower packing offers thelowest pressure drop per theoretical stage of any randompacking available.

IMTP tower packing has a high void fraction compared toother random packings of similar size. Large void fractionsprovide superior high liquid rate capacity as well as alower pressure drop. Lower pressure drop in combinationwith the unique, self-draining shape reduces liquid holdupon the packing, which in turn, reduces the areas wheresolids could deposit.

Acid Gas Removal

One of the most widely used commercial absorptionprocesses is the removal of CO2 and/or H2S from a gasstream by contacting it with an amine solution such asMEA, DEA,or MDEA. The activated forms of MDEA solu-tion such as Ucarsol®, GAS/SPEC® and aMDEA® have alsobeen widely used in this process. Installation of INTALOXMetal Tower Packing in these towers offers lower pres-sure drop which provides several benefits. This system is moderately foaming and the lower pressure drop provided by IMTP packing reduces foam generation andthe use of costly anti-foam agents. Lower pressure dropalso reduces energy consumption and solvent degradationdue to higher operating temperatures. The predictableperformance of IMTP packing, when used with INTALOXHigh Performance Distributors, and the packing’s highmechanical strength allow the use of very deep beds.Koch-Glitsch has successfully packed amine absorbers andregenerators with beds well over 40 feet [12m] deep.Column height normally occupied by a redistribution sys-tem can be utilized by additional packing.This reduces thecost of additional tower internals when replacing existingtrays. These benefits can be extended to other gas treat-ing systems such as hot carbonate (e.g. Benfield) and phys-ical solvent (e.g. Selexol®) systems. Koch-Glitsch hasinstalled IMTP packing in practically all of the amine, hotcarbonate and physical solvent systems, as well as manyother gas treating systems. This vast experience can beused to ensure maximal performance of any gas treatingsystem.

Ucarsol® is a registered trademark of Union Carbide CorporationGAS/SPEC® is a registered trademark of Dow Chemical CompanyaMDEA® is a registered trademark of BASF AktiengesellschaftSelexol® is a registered trademark of Union Carbide Chemicals & Plastics

9

Feed

Feed

Feed

One application that is common to both natural gas plantsand olefins plants is the separation of methane from heavierhydrocarbons. Generally, these columns are operated at highpressure and low (cryogenic) temperature. Installation ofINTALOX Packed Tower Systems in demethanizer columnsprovides several benefits. Well designed INTALOX PackedTower Systems take into account the close liquid and vapordensities and low surface tensions of this system. High per-formance Intalox tower internals in combination with IMTPhigh performance packing provide maximum separation effi-ciency. Increased efficiency permits operation at lower refluxratios, reducing the condenser refrigeration requirement. Inaddition, IMTP packing provides increased capacity orthroughput with low pressure drop. For new construction,the column diameter is minimized, reducing the requiredcapital investment. In revamp projects, the use of IMTP pack-ing allows maximum throughput for the existing column.IMTP packing is available in a wide range of materials, includ-ing aluminum, and in sizes ranging from #15 to #70. In somecases, the benefits of INTALOX Packed Tower Systems canbe extended to deethanizer columns as well. Koch-Glitschhas extensive experience packing hundreds of light hydro-carbon distillation towers to maximize performance.

OverheadProduct

Steam

Sour Water

Acid Gas

BottomProduct

Demethanizer

Sour Water Stripper

Sour water stripping is an important part of integrated indus-trial aqueous waste management, particularly in petroleumrefineries. The sour water stripper is designed to remove H2Sand NH3 from process water. This can be achieved by con-tacting the sour water with stripping steam in a packed bed.IMTP packing provides very high stripping efficiency allowingfor shorter packed bed depths or the use of less strippingsteam. Revamping a sour water stripper from trays or con-ventional random packing to IMTP packing can help refineriesmeet today’s increasingly stringent effluent water quality reg-ulations. Process water may contain contaminants that cancause scaling, fouling or foaming problems. The very high voidfraction and low pressure drop of IMTP packing help to alle-viate these problems. Additionally the wider operating rangeof IMTP packing provides the flexibility required to meet the additional stripping requirements during peakoperation.

10

The Fundamental Driving Force

IN MASS TRANSFER TECHNOLOGY

Worldwide Headquarters

Koch-Glitsch, LPP.O. Box 8127Wichita, KS 67208-01274111 E. 37th Street NorthWICHITA, KANSAS 67220Tel: (316) 828-5110Fax: (316) 828-5263

North American Offices

Koch-Glitsch, LP12221 E. Sam Houston Parkway N.HOUSTON, TEXAS 77044Tel: (713) 427-7600Fax: (713) 427-7613

Koch-Glitsch, LP4900 Singleton Blvd.DALLAS, TEXAS 75212Tel: (214) 583-3000Fax: (214) 583-3377

Koch-Glitsch, LP5385 Orchardview Drive SEEAST CANTON, OHIO 44730Tel: (330) 488-1279Fax: (330) 488-1656

Koch-Glitsch CanadaCo.18 Dallas St.UXBRIDGE, ONTARIOL9P 1C6, CANADATel: (905) 852-3381Fax: (905) 852-7821

European Offices

Koch-Glitsch Italia S.r.l.Via Tonale 50, Casella Postale1324061 Albano S. AlessandroBERGAMO, ITALYTel: +39-035-328611Fax: +39-035-328600

Koch-Glitsch UKKing Street, FentonSTOKE-ON-TRENT ST4 2LTENGLANDTel: +44-1782-744561Fax: +44-1782-744330

Asia Offices

Koch-Glitsch Japan Corp.7th Floor, KSS Gotanda Bldg. 21-8Nishi-Gotanda 1- chomeSHINAGAWA-KU, TOKYO141-8538, JAPANTel: +81-3-5435-8560 Fax: +81-3-3491-3523

Koch-Glitsch Korea Co., LtdDongsung Bldg. 8th Floor17-8 Yoido-dongYongdungpo-kuSEOUL 150-010, KOREATel: +82-2-3775-2650Fax: +82-2-2780-1954

Koch-Glitsch India Ltd.42 Kalpataru CourtG. Gidwani Marg., ChemburMUMBAI 400074, INDIATel: +91-22-2520-2050Fax: +91-22-2520-2040

For a complete listing of Koch-Glitsch offices,visit us on the internet: www.koch-glitsch.com

For emergencies in the USA: 1-888-KOCH-911

Koch-Glitsch Corporate Offices

NOTE:The information contained in this bulletin is believed to be accurate and reliable but is not to be construed as implying any warranty or guarantee of performance.

Bulletin KGIMTP-1 2M0303B Printed in U.S.A.©Copyright 2003 Koch-Glitsch

INTALOX® , IMTP®, FLEXIRING®, HY-PAK®, CASCADE MINI RINGS® and β-ETA RING®

are registered trademarks of Koch-Glitsch.

IMTP® #60 U.S. Patent No. DES 379,096High Strength FLEXIRING® U.S. Patent No. 5,314,645β-ETA RING® U.S. Patent No. 5,885,489