Introduction - Koch-Glitsch

1 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 advantages realized in distillation have been abundantly applied inabsorption, stripping, liquid-liquid extraction and direct contact heat transfer operations as well. Since its Introduction in the late 1970s,IMTP packing has been successfully used in thousands of mass transfer towers with diameters ranging from 6 inches to 40 feet [150 mm 12 m].

2 Simultaneously, a line of high performance tower internals was developedto ensure the maximum performance of each packed tower is engineers have extensive experience applying these technolo-gies to a variety of processes, providing the best solution for each booklet provides information for quick sizing of packed columns usingINTALOX metal tower packing. The charts provide information forhydraulic ratings and relative packing efficiencies in terms of HETP (based on a standard hydrocarbon test system) as well as KGa values for theabsorption of addition, Koch-Glitsch offers the hydraulic ratingprogram,KG-TOWER Software, that may be downloaded from thewebsite at recognizes that not all applications require the use of IMTP high performance random packing.

3 For those applications, koch -Glitschoffers a wide variety of additional tower packings, such as -ETA RING ,CASCADE MINI-RINGS ,HY-PAK ,FLEXIRING and Raschig RingRandom Packings. For information on these packings, refer to DeliveryIn addition to IMTP packing, Koch-Glitsch has other metal or plastic randompackings to provide optimum performance whatever your application. Incommon materials, most packings are in stock for immediate shipment toget you back on line. For emergencies, call the Hotline of your nearestKoch- glitsch the US, call the Hotline at Europe, call 0044 1782 744 561 or your local Koch-Glitsch 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 conventionaltrays.

4 Many absorption and stripping towers, especiallythose aiming for high capacity or close approach toequilibrium, rely on IMTP packing. The low pressuredrop, high specific heat-transfer coefficient, as well as thefouling resistance of IMTP packing contributes to itssuccess in heat transfer towers, such as olefin plantquench 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 rates,the packing exhibits a region of improved efficiency (lowHETP) where high vapor turbulence influences the liquid surfaces and improves the mass defines two packing properties from a performance curve:1. The System Base HETP is the constant HETP value produced by uniform The Maximum Efficient Capacity is at the highest vapor rate where the packing maintains the System Base : Efficient Capacity is not the same as the hydrauliccapacity or flood point.

5 Koch-Glitsch rates high performancepackings by both Efficient Capacity and Hydraulic System Base HETP concept raises important questions: What is the System Base HETP of a packing in a given system? (Refer to page 4.) How much does liquid distribution quality affect HETP? (Refer to page 5.) Which liquid distributors should be chosen to make a tower perform near its System Base HETP? (Refer to the Tower Internals Guide,KGMTIG-1.)2 IMTP high performance Random Packing Flood PointIMTP Packing performance UnderUniform Liquid and Vapor DistributionVapor RateHETP (Height Equivalent to a Theoretical Plate)Maximum Efficient CapacitySystem Base HETPM aterials of ConstructionINTALOX 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 zirconiumPacking CapacityCapacity CorrelationThe Maximum Efficient Capacity of IMTP packing in a non-foaming system can be estimated as:Nomenclature and DefinitionsL:Liquid mass rateG:Gas mass rate L:Liquid density G:Gas densityV:Superficial gas velocity, ft/s or m/sX= Flow ParameterCs= V Capacity Factor, ft/s or m/sFs= V F-Factor, ft/s (lb/ft3)1/2or m/s (kg/m3)1/2LG G L G G L GData RangeKoch- glitsch routinely designs towers up to 90% MaximumEfficient Capacity.

6 This limit leaves an estimated 11% turn-up before the packing loses its design < < < < > , use #15 IMTP #25 IMTP #40 IMTP #50 IMTP #60 IMTP #703If < , use, = Limits :Surface tension, dyne/cm :Liquid viscosity, cP 20 Efficient Capacity, Csc= Co 20 efficiency of packing in most distillation towers is expressed as HETP or height equivalent to a mass transfer efficiency of all mass transfer devicesis dependent on the system properties of liquid viscosityand surface tension. The efficiency of a packed systemalso depends on the uniformity of liquid and vapor concept of System Base HETP assumes that a specific separation receives uniform liquid and vapor distribution.

7 This concept is useful because it isolatesthe system s effect on HETP from the distribution a first approach in projecting HETP values, Koch-Glitsch has developed a correlation for estimatingHETP from the system properties. It is desirable to confirm the projected HETP values with test data incolumns having uniform vapor and liquid distribution in the same system or a system having very similar properties. Koch-Glitsch has an extensive bank of operating data from a wide variety of systems and canprovide reference data to confirm final HETP valuesupon efficiency correlation applies to systems which: are non-aqueous are non-reacting and non-ionizing have low to moderate relative volatility (less than three)In these systems, the System Base HETP of IMTP packingfor distillation and reboiled stripping services can be estimated by:The packing efficiency in other services or other systemsmust be estimated by other liquid and vapor distribution will causeactual HETP values to be substantially greater than theSystem Base HETP value.

8 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 represents proper liquid distribution for a commercial 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 Efficiency4 System Base = Afor < cP System Base = Bfor > cP 20 Volatility < 3If > 27, use, =27 :Surface tension, dyne/cm :Liquid viscosity, cPValues of A and B for the HETP CorrelationIMTP Packing 25No. 40No. 50No. 60No. RangeCorrelation < < < < [ ] 5 Koch-Glitsch INTALOX Packed Tower Systemsarepredictable and reliable separation columns containingwell-matched high performance packing and state-of-theart liquid and vapor distributors.

9 Koch-Glitsch s globalexperience is second to none and includes thousands ofcolumns in distillation, absorption, stripping, liquid-liquidextraction and heat transfer combination of INTALOX high performance internalsand IMTP high performance random packing provides thehighest random packing performance available in has developed a series of liquid distributorswith attributes to maximize packed tower attributes are well understood and have beenincorporated into INTALOX high performance distribu-tors. Koch-Glitsch introduced a distributor rating systemfor quantifying distribution quality and 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.

10 In addition, the distrib-utor must provide a sufficient gas passage area to avoid ahigh pressure drop or liquid 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 pointThe significance of the Koch-Glitsch distribution qualityrating system is the accurate prediction of tower 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 temperaturesA tower containing deep beds of IMTP high efficiency ran-dom packing, designed to achieve many theoretical stagesor transfer units, is very sensitive to liquid devices are critical to the performance of the liquid distributor and the packed column.