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    HEAT EXCHANGER TUBE INSERTS -

    AN UPDATE WITH NEW APPLICATIONS IN CRUDE DISTILLATION UNITS

    VACCUM APPLICATION AND REBOILERS

    By:

    Artur W. Krueger, Senior Consultant, Petroval, Houston

    e-mail:artur.krueger@gmail.com

    Francois Pouponnot, Petroval, France

    e-mail:f.pouponnot@petroval.com

    Presented at:

    AIChE Spring Meeting

    April 23 - 27, 2006 - Disneys Dolphin Hotel, Orlando, FL

    ABSTRACT

    Heat exchanger tube inserts have been used for many years as reliable means forheat transfer enhancement and fouling mitigation in petroleum refineries and chemicalplants. In this paper, we will present several new application examples for optimization ofheat exchangers and related equipment, resulting in enhancement of the function of suchequipment and improvement of on-line availability of the plant.

    Usual insert applications in refining pre-heat trains continue to give goodperformances for fouling mitigation and heat transfer conservation. For the refiner, thisimprovement brings interesting energy savings but also longer run times with better overallperformance of the pre-heat train. Tube inserts are largely used in CDU and VDUapplications. In some new applications such as reboilers (liquid and mixed phase flows),the observed efficiency was valuable because the shorter initial service times have beenexpanded substantially (in some cases 4 to 6 times longer than the initial service time), andwith higher efficiency levels achieved during this extended service time.

    Some of these applications and results are described in this paper.

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    I. TUBE INSERT DESCRIPTIONS

    a. SPIRELF

    The Spirelf system falls within the category of "on-line mechanical cleaningdevices". The principle is based on the insertion of flexible metal devices, in spiral form, intothe tubes of "shell and tube type" heat exchangers. The devices are stretched over thelength of each heat exchanger tube and are held in place by straight wires at each end(inlet and outlet).

    Fig. 1a Fig. 1b Fig 1c

    OPERATING PRINCIPLE

    After installation the insert stays under tension. Under the effect of the circulatingflow, it enters into vibrations, radially and axially. The repeated contact between the loopsof the devices and the inner tube wall has two effects:

    prevent the formation of deposits, break the boundary layer in the tube side flow.

    As a consequence, the mechanical effect of the SPIRELF system reduces foulingbuild-up inside heat exchanger tubes and the turbulent effect achieves an improvement ofthe heat transfer rate (the internal heat transfer coefficient is multiplied by 1.8). Overall thesum of these two effects results in a reduction of the apparent fouling factor by as much asthree-quarters.

    b. TURBOTAL

    The Turbotal system falls within the category of "on-line mechanical cleaningdevices". The main aim of Turbotal is the control of fouling in heat exchangers. Theprinciple is based on the insertion of rotating metal devices, in rigid helicoidal form, into the

    tubes of "shell and tube type" heat exchangers.

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    Fig. 2a Fig. 2b

    HELICOIDAL DEVICE ROTATINGBY THE FLUID FLOW

    Fig.2 c

    OPERATING PRINCIPLE

    Turbotal is a system, which is held at the inlet of tubes by a fixing device allowingthe mobile to rotate around its axis by means of the fluid flow.

    This rotation causes a high turbulence in the flow and improves thus the internalheat transfer coefficient. As the boundary layer is continuously renewed, the walltemperature is lowered and fouling is slower. Combined with the mechanical effect of therotation, TURBOTAL has a preventive effect against fouling with this two effects:

    prevent the formation of deposits, break the boundary layer in the tube side flow.

    The TURBOTAL is extremely versatile. The rotation speed can adapt itselfaccording to the operating conditions. The TURBOTAL is able to cope with :

    flow rate variation fluid properties variations (viscosity, density...) accidental vaporization (caused for instance by massive water occurrence)

    The fixing device of the coil is placed at the outside of the tube. The design of thecoil itself is adapted for each case to the geometry of the tubes and the process conditions.As a consequence, the mechanical effect of the Turbotal system reduces fouling build-upinside heat exchanger tubes and the turbulent effect achieves an improvement of the heattransfer rate (the internal heat transfer coefficient is multiplied by 1.8). Overall the sum ofthese two effects results in a reduction of the apparent fouling factor by as much as three-quarters.

    c. AREAS OF APPLICATION OF TURBOTAL AND SPIRELF

    Due to the operation principle, Turbotal and Spirelf devices can be used in all multi-tubular heat exchangers with straight tubes, where deposits within the tubes are found.

    The Turbotal and Spirelf system applies:

    to all fluid up to 360C-680F, in a liquid phase, where flow velocities are between 2 and 6 ft/s (0.6 to 3.0 m/s) inclusive, in pipes of an outside diameter between 1/2 and 2 inches inclusive in tubes of length between 10 and 33 ft inclusive.

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    The first applications were in the refinery industry, particularly in atmosphericdistillation preheat trains in which the fight against fouling is crucial. Nowadays Turbotaland Spirelf systems can also be applied to other industries, such as chemical andpetrochemical applications.

    d. FIXOTAL

    Fig. 3a Fig. 3b Fig. 3c

    FIXOTAL is a fixed device, which has been developed by TOTAL. Its function is

    primarily to increase the thermal efficiency of tubular heat exchangers and also to reducethe tubes fouling rate.

    DESCRIPTION OF THE DEVICE

    FIXOTAL consists of a wire coil, which is inserted inside every tube, with the wire infirm contact with the inside tube wall. Once in place, the device has no possibility of theslightest displacement (no vibration, no rotation, and no translation), the device can beeasily removed if necessary.

    The main effect of the wire is to create a turbulence effect, thus decreasing theboundary layer at the wall. The result is a significant increase of the tube side heat transfercoefficient, resulting in of a moderate increase of pressure drop through the tube.This hastwo major consequences :

    Increase of the thermal efficiency of the exchanger, due to an increase of theoverall heat transfer coefficient. The extent of the gain depends on the split of the overallheat transfer resistance between the inside and the outside tube surface.

    Decrease temperature gradient between tube wall and bulk. This leads to adecrease of the tube side surface fouling rate, especially with fouling which is walltemperature dependant.The parameters influencing the heat transfer enhancement and thepressure drop have been investigated at pilot scale for one & two-phase flows.

    To summarize, FIXOTAL is easy to install technology, which increases the thermalefficiency of tubular heat exchangers and also reduces their tube side fouling rate.

    Its key advantages are :

    sustain of heat duty reduction of fouling debottlenecking aspect for existing undersized equipment

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    Fig. 4: U-tube equipped with Fixotal

    II. APPLICATIONs OF TUBE INSERTS TO OIL REFINERIES

    Spirelf, Turbotal and Fixotal are especially well adapted to the use in crude oilunits, where the main fouling layer is composed by asphaltenes. In this application, the aimis primarily energy efficiency but also to improve maintenance management throughextension of exchanger run times which at the same time results in improved throughputcapacity.

    Other units that can be equipped by Spirelf, Turbotal and Fixotal aredesulphurisation units, hydrotreaters, with the condition of liquid phase tube side of theexchangers. Application on Naphtha, Kerosene, Gas Oil Light Crude Oil have beendeveloped for several years successfully.

    a. Main advantages of Spirelf, Turbotal and Fixotal

    Spirelf, Turbotal and Fixotal installation and use do not require any modification ofthe heat exchanger.

    Increased heat transfer rate :

    through higher flow turbulence (inner heat transfer coefficient -X 1.8) reduction of fouling and coking in heat exchanger tubes result : energy savings of up to US $ 500,000 per year, example : EEC installation - 23,800 barrels or 3 400 tons of oil equivalent/year.

    Average cost/benefit ratio: 1 : 5

    Reduction of maintenance work/ cost :

    decrease of exchanger cleaning through reduction of tube side fouling extended run time through increase of cleaning intervals example:

    for unequipped exchangers = 6 month cleaning cycles,for equipped exchangers = 12-20 months cleaning cycles

    extended tube life/reduced leakage due to reduction of under-layer corrosion designed to avoid mechanical tube erosion.

    De-bottlenecking improved throughput capacity :

    improved operating conditions at main column through equipment of pump-around/reflux line exchangers

    in case of limited furnace capacity, increase of crude temperature possible byequipping exchangers directly before furnace (29 degr. F temperatureincrease documented compared to unequipped train)

    improved throughput capacity due to reduced need for exchanger cleaning(runtimes multiplied for equipped exchangers)

    better cooling of outgoing products to storage

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    b. Pressure drop

    Delta-P caused by Spirelf, Turbotal and Fixotal devices = between 1 and 3 psior 0.1 and 0.2 bar per pass (depending on tube dimensions, crude type, flow velocity)Delta-P for two-pass exchanger = 3 psi or 0.2 bar (average value at 1 m/s flow velocity)

    Delta-P caused by fouling to be considered for comparison Higher Delta-P resulting in increased flow turbulence (inner heat ~ transfer

    coefficient X 1.8)

    c. New cleaning frequencies

    By experience : the cycle duration is generally multiplied by 2 sometimes by 3;which translates in avoidance of frequent cleaning operation. (depending on the tubediameter, the fouling degree...)

    Cleaning frequency before a tubeinserts equipment

    Service time of tube inserts or new cleaningfrequency if chemical cleanings are not used

    6 months (Turbotal, Spirelf and Fixotal) 1 year to 1 ,5 year1 year (Turbotal, Spirelf and Fixotal) 2 years to 3 years

    18 months (Spirelf and Fixotal) 3 years and more

    d. Typical installations

    crude preheat train (with crude flow tube side) last exchangers before furnace,pumparound/reflux lines, product lines to storage

    Retrofit installation New exchangers to be equipped to improve exchanger performance/extend

    anticipated run time.

    e. Possible alternative solution

    In order to be able to run for longer time, there is possibility to perform somechemical cleaning on line with Spirelf and Fixotal in place. Tube inserts are used in order tokeep high heat transfer efficiency and the chemical cleaning at regular period is a solutionto recover the initial efficiency during an extended service time.

    Fig. 6

    Heat Exchanger Fouling Trend

    50.0

    60.070.0

    80.0

    90.0

    100.0

    110.0

    120.0

    130.0

    140.0

    150.0

    160.0

    SOR+1

    SOR+21

    SOR+41

    SOR+61

    SOR+81

    SOR+101

    SOR+121

    SOR+141

    SOR+161

    SOR+181

    SOR+201

    SOR+221

    SOR+241

    SOR+261

    SOR+281

    SOR+301

    SOR+321

    SOR+341

    U-Value

    Solvent Cleaning Effect

    Spirelf EffectWithout Spirelf

    With Spirelf

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    III. INDUSTRIAL RESULTS : THE TURBOTAL SYSTEM - EFFICIENCYCOMPARISON IN A CRUDE UNIT

    a. Unit description

    In November 2003, Turbotal has been installed in CDU 1 heat exchangers 8ABEF.In order to evaluate the efficiency of the Turbotal in these heat exchangers, a comparisonstudy has been performed between the 2 branches of the pre heat train (one equipped8AB, one unequipped 8EF, see fig below).

    Fig. 7

    After 1 year operation, an evaluation based on refinery results is prepared. Workingperformance of equipped heat exchangers is still around 40% higher than the unequippedones. The observed extra DP (average value around 0.6 bars) due to Turbotal is in line withthe normal extra DP evolution. Based on these experimental results, the energy savingsgenerated by a better preheat train efficiency are already paid back.

    b. Heat exchanger characteristics (tube side) (Used for expected for study/real)

    Unit: Crude Distillation Unit (Pre heat train) Tube number / bundle: 1 424 Tube length: 6,100 mm OD / BWG: / 14 Product tube / shell side: Crude / Atmospheric residue Flow velocity (tube side): 1.1 m/s Tube insert: Turbotal Replacement frequency: 2 years

    The working conditions since the installation have been stabilized and generallymatch with the expected working conditions in tube side.

    % U increase due to tube insert

    0%

    10%

    20%

    30%

    40%

    50%

    60%

    70%

    80%

    90%

    100%

    11/11/2003 11/01/2004 11/03/2004 11/05/2004 11/07/2004 11/09/2004 11/11/2004

    %increase

    % U increase Eq/Uneq-1

    Fig. 8

    Heater

    E 8 EE 8 F

    E 8 AE 8 B

    Equipped heat exchangers

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    Explanation of the evolution:

    Fouling part of the new tubes under Turbotal control, Fouling stabilization in equipped tubes and turbulent effect for heat transfer

    compared with fouling accumulation situation in unequipped ones.

    According to the flow sheet, the shell side product is atmospheric residue which isusually a fouling product which strongly influences the global duty of the heat exchangerand against tube insert cannot work. The equipped heat exchangers are now running with50% improvement for the duty compared than without. The fouling in tube side would be avery substancial limitation of the global heat transfer in these heat exchangers.

    The Delta T (Outlet Inlet) evolution between both branches has been quitesignificativelly improved due to Turbotal:

    Average value for the first year inlet outlet Delta T DT after 1 yearFlow rate value in 8AB (C, tube side) 203 242 39 37Flow rate value in 8EF (C, tube side) 212 242 30 27

    Tube inserts installation in heat exchanger 8AB increased the average DT duringthe first year by 9C. A conservation of 9C is possibly observed at the furnace inlet byusing tube insert during this period. The final monitored Delta T is still +10C

    c. Energy savings evaluation

    The interest of Turbotal installation is both cleaning effect and turbulent effect intube side by mechanical action. As it has been observed in this heat exchanger, it bringssome better heat transfer performance which help to keep higher outlet temperature of theheat exchanger and when it is installed into the most strategic heat exchanger, this thermalimprovement can bring some money savings due to energy savings among others.

    In this particular case, energy savings can be calculated as follow:

    Energy saving calculation:

    Data: normal crude flow-rate : 800 metric t/hr- specific heat of crude : 0.65 kcal/kg.C at 210C- furnace yield : 0.85- heating power of fuel : 9,700 kcal/kg1C higher at the furnace inlet corresponds to a daily savings of:800,000 x 24 x 0.65= 1,500 kg of fuel saved per day per C

    0.85 x 9,700 (9 bbl of fuel oil saved per day per C)Energy savings during one year of run : 3,285 bbl of fuel oil per year per CBased on 20 Euro / bbl for fuel oil: Euro 65,700 savings per year per C

    With Turbotal, it has been calculated during the 6 first months of last run that animprovement of 9C is a realistic improvement in these heat exchangers.

    Euro 591,300 savings per year per 9C

    Global energy savings over 1 year : Euro 591 300 during the first year

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    This estimate is based on energy savings during one year. Then the 18 additionalmonths would generate only purely energy savings. Usually Turbotal installation generatesalso production loss savings and maintenance savings (if in between shutdown can beavoided).

    d. Conclusion in this CDU

    Results of efficiency improvement and technical characteristics of this evaluationare quite positive because it is in line with the expected results:

    The heat transfer improvement (U value) was at start of run around + 50%with an average value during the 6 first months around + 30 % and a final stabilization at +20%. During the second semester, the duty increased from 20 % up to 50%. The increasedwas especially visible during a stabilized period between end of August and November2004.

    This improvement results into higher outlet temperature of +10C for equippedbranch. And the average improvement is around +9C.

    Energy savings are then better then initially expected Pay back time in less than 6 months.

    IV. INDUSTRIAL RESULTS : SPIRELF IN CDU

    Fig 9.General working conditions for this heat exchangers are: 800 tubes and 2 passes on tube side (for each bundle), Flow rate: 249 t/h (Fluid velocity:1.2 m/s), Desalted crude is flowing tube side and Top pump around is in shell side, Straight tubes 6,096 mm / OD 19,05 mm / BWG 14. Cleaning frequency of 1.5 years, when the hydraulic limit is reached. 0.3 bar SOR and 1.8 bar EOR Heat exchanger situated just after the desalter Strong fouling deposit has been observed at the cleaning time.

    After Spirelf installation, the fouling factor had been reduced to the minimal valueand kept under optimal value and optimized working conditions. Since it isinstalled, the fouling factor is stabilized to a low value and no excessive extra DPhad been observed.

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    V. INDUSTRIAL RESULTS : THE TURBOTAL SYSTEM

    APPLICATION WITH INBETWEEN REMOVAL

    Fouling Factor survey

    Exchangers T29&T30

    0

    10

    20

    30

    40

    50

    60

    70

    0 40 80 120 160 200 240 280 320 360 400 440 480 520 560 600 640

    Duration in days

    m2

    .C.h/kcal x 10 000

    T29

    T30

    18 months run with Turbotal

    Turbotal

    Removal

    and cleaning

    Fig. 10

    After 18 months operation Turbotal had been removed because of productionunexpected turnaround for a specific problem. The normal shutdown planned for 6 monthslater, the refinery decided not to install Turbotal for only 6 months but to go on without itduring the final part of the run. The fouling factor increased dramatically without Turbotalwhere as it was under control during the period with Turbotal. At the shutdown, theyreinstall the Turbotal in order to keep control with fouling factor. In this case the foulingfactor evolution (slope) had been reduced by more than 3 time the one without tube inserts.

    Since November 2002, this 2 heat exchangers are equipped with Spirelf with theidea to run and to perform some chemical cleaning every years.

    VI. INDUSTRIAL RESULTS : VDU APPLICATION - RELIABILITYENHANCEMENTS WITH THE FIXOTAL SYSTEM

    Heat exchanger characteristics

    Unit: Vacuum Distillation Unit (Pre heat train) Position in the pre heat train: Before the furnace Tube number / bundle: 1200 Tube length: 6,100 mm OD: 1 Replacement frequency: 3 years (since 1998) Product tube / shell side: Atmospheric residue / bottom reflux Flow rate (tube side): 400 t/h

    Installation problematics

    Before installation, the heat exchanger was 6 passes with a strong problem ofefficiency due to:

    Strong fouling even with high fluid velocity (around 2.2 m/s) Short residence time (compared with the effective heat transfer coefficient

    with fouling)

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    Observed results and production constraints:

    Poor heat transfer efficiency High extra DP due to fouling Cleaning frequency of 6 months Furnace bottleneck because of lower inlet temperature

    Decided modifications:

    Pass configuration modification: from 6 to 2 passes (Flow velocity from 2.2 to0.8 m/s)

    Fixotal installation

    Expected results:

    Reduction of pass number: increase of residence time and global heattransfer. Strong increase of the fouling is foreseen (X3).

    Fixotal installation: fouling mitigation and heat transfer increase by efficientturbulent effect at the tube wall.

    Observed results :

    Efficient heat transfer coefficient during the run Comparable service time Chemical cleaning every 6 months to recover periodically the initial

    performance.

    Fouling factor evolution in VDU

    0 15 30 45 60 75 90 105

    120

    135

    150

    165

    180

    195

    210

    225

    Days

    Rf(m2.

    K/W)

    Initial curve (6 passes configuration)

    Expected curve (2 passes without Fixotal)

    Observed curve (2 passes with Fixotal)

    Fig. 11

    Conclusion:

    Good thermal efficiency due to pass number reduction and Fixotal installation

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    Good fouling mitigation due to Fixotal. Comparable fouling evolution whereasit should have been 3 times more severe and bring quite strong problem of the service timeand production enhancement.

    Chemical cleaning every 6 months in order to recover the initial efficiency butwithout removing Fixotal. A replacement is expected every 4years.

    VII. INDUSTRIAL RESULTS : REBOILER APPLICATIONS

    Generally reboilers are heated on shell side by steam, and the organic productflews tube side.

    In terms of heat transfer, there is a big difference between the outside and theinner heat transfer coefficients, and this last one constitutes the main resistance for theheat transfer. This characteristic is even more pronounced in case of fouling coming fromthe organic product. Consequently, any increase of the inner coefficient (IHTC) translatesto about the same improvement on the overall heat transfer coefficient (OHTC).

    a. Action of the Spirelf System on vertical reboilers performance at start-up.

    Improvements to be expected from Spirelf System. Spirelf devices have two actions, first a turbulent effect from the start-up of

    the reboiler, then a combinated effect, turbulent and mechanical, giving a reduction of thefouling layer during the service time of the reboiler.

    From the start-up, through the increase of turbulence coming from the shapeof the devices, there are different types of action on almost each region of the boiling tube.

    Apart from the annular flow region where there is not enough liquid phase,Spirelf increases the performance of the convective boiling:

    In the slug flow zone, due to its presence (as a packing), Spirelf reduces theformation of large size bubbles (reduction of the coalescence of small bubbles). It maintainsa longer time the bubbly flow, more efficient than the slug (or plug) flow.

    In the bubbly flow region, without change of the number of nucleation sites(mainly depending on the metal surface), the increase of turbulence associated to themotion of the spring going into contact with the wall, reduces the residence time of thebubbles on the metal surface, giving a better efficiency for each site of nucleation.

    In the submerged area, at the lower part of the reboiler when this one isvertical, Spirelf reduces the laminar layer thickness on the surface of the tubes, increasingthe convection coefficient (see description in fig. 12)

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    b. Special case of thermosiphon reboilers.

    In the case of thermosiphon reboilers, the increase of vaporization due to Spirelfleads normally to increase also the flow rate of product (when flowing in the tubes), but atthe same time, the inherent extra pressure drop introduced by the springs has as effect toreduce it.

    At the start-up, the global effect of Spirelf on a thermosiphon reboiler can betranslated by:

    Less liquid but more % vaporization = same duty

    In fact, we have always noticed that at the start-up, the performance of athermosiphon reboiler was not affected by Spirelf. This result has been observed every

    time when such type of reboiler has been equipped with Spirelf devices.

    c. Spirelf effect in service

    Generally fouling grows on the tube surface, and a source of fouling on the organicproduct side, comes from the high temperature of the wall, heated by medium pressuresteam (around 200 C 400 F). After forming of the first layer of deposit on the wall, thetube surface becomes rough which makes for easier formation of new deposits on it. As atthe same time, the wall temperature becomes higher due to the resistance of the foulinglayer, organic compounds are transformed into coke. It is important, in order to preventlater severe fouling, to reduce the start-up the fouling formation from the beginning.

    Without to take into account the mechanical effect of the Spirelf springs throughtheir contact with the wall, the increase of turbulence itself reduces the laminar layerthickness, reducing the wall temperature and consequently fouling phenomena from thebeginning.

    This reduction of fouling is illustrated hereafter in one industrial case, where adirect comparison of performance has been made between two identical parallel reboilers.

    Single phase liquid

    Bubbly flow

    Slug flow

    Annular flow

    Fig. 12

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    d. Unit description: Spirelf Effect for increased efficiency in duty and service timefor thermosiphon reboiler

    This is an application of Spirelf in a vertical reboiler, where strong fouling situationwas a bottleneck issue for the chemical plant. This unit dealing with fluoric compoundrequired a monthly water injection in order to clean them and to come back to normalsituation.

    The initial working conditions were:

    Natural thermosiphon 1 heat exchanger of 80 tubes and 1 pass on tube side, Flow rate: between 15 and 30 t/h, Boiling organic is flowing tube side, Straight tubes 1,500 mm / OD 27.45 mm / internal diameter 21.4 mm.

    Solution description

    Due to the low velocity in single liquid phase, the implementation of Spirelf in this

    reboiler was proposed in order to generate a turbulent effect in this part of the tubes. Thiseffect was expected to increase the convection coefficient of the liquid and accelerate thegas formation.

    Due to higher turbulence and reduction of boundary layer thickness because ofSpirelf, the fouling reduction was estimated around 50% reduction.

    Service time with Spirelf is usually doubled (theoretical expectation). As normalSpirelf life time is about few years, if fouling mitigation is strongly effective it can last around5 times or more the initial service time.

    Observed results

    Initial evaluation after the first installation in February 2004 after 3 monthsinstallation the Spirelf was still in service and the 6 months service time without watercleaning was expected at the time of the evaluation. Observed results are a strongmitigation of the fouling deposition. Observed U value in equipped situation is nowstabilised at higher U value than the expected stabilisation (around 200). As additionalresult, it is more than twice higher than the stabilisation without Spirelf.

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    Thermosiphon Reboiler, Spirelf effect

    050

    100150200250300350400450500

    0 20 40 60 80 100days

    Uv

    alue

    2003 (Without Spirelf)

    2004 (With Spirelf)Cleaning by

    water injection

    Fig. 13

    There are 4 reboilers in the unit, and 2 of them were in bottleneck situationbecause of fouling. After this test, the chemical plant decided to equip both critical reboilers

    in order to be able to run 1 year with water injection every month.

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    List of Publications

    The Petroval Tube Inserts Systems: SPIRELF, TURBOTAL, and FIXOTAL

    have been described in the following publications:

    Petroles et Techniques n295, Janvier fevrier 1983

    Chem. Eng. Progress, September 1991,"Heat Transfer Heads into 21st Century"

    ASME 1995, National Heat transfer Conference, 7 August 1995, "Field ofapplication of double enhanced tubes in shell and tube and air cooled heatexchangers",

    Hydrocarbon Processing, February 1998, "Revamping Crude Units"

    AIChE, March 8-12, 1998, "New Heat Integration Techniques for BoostingProfitability",

    AIChE, March 14-18, 1999, "A Practical Approach to Fouling Mitigation in

    Refineries: Spirelf System".ESDU Doc. 000 16,2000, Heat exchanger fouling in crude oil distillation units,

    Proceedings, August 2000, 2nd Intl. Conference on Petroleum and GasPhase/Fouling, Copenhagen,

    UEF Heat Exchanger Fouling Conference, 2001, Davos (Switzerland)

    Publico, 2001, Heat Exchanger Fouling Mitigation and Cleaning Technologies, Ed.H.Mueller-Steinhagen.

    AIChE Spring Meeting, March 2002

    ARTC 5th Annual Meeting, April 2002, Session on Refining and PetrochemicalTechnology, Bangkok

    ARTC Reliability Conference, November 2002 Singapore (SK Corp. Korea)

    HDT Haus der Technik Heat Exchanger and Cleaning Seminar, Sept. 2003 BadDuerkheim (Germany)

    ARTC 7th Annual Meeting/Reliability Conference, April 2004 Singapore (ThaiCaprolactam/Petroval)

    AIChE National Meeting, April 2004, New Orleans (Shell/SGS, Argonne, Petroval )

    HOD Intl. Conference on Heavy Organic Depositions, Nov. 2004, Los Cabos(Mexico)

    NPRA National Petrochemical and Refiners Assoc. Technical Q&A sessions:

    1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005

    ECI Conference on Heat Exchanger Fouling and Cleaning, Bad Irsee, Germany,2005

    SGS, Shell Amsterdam Conference on Heat Exchanger Fouling and Cleaning,2005

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    Page : 1/2QUESTIONNAIRE

    SPIRELF/TURBOTAL/FIXOTAL EVALUATION AND DESIGN

    This evaluation is related to the exchanger to be equipped, therefore the

    following information is required :

    Customer : ...................

    Location : ....................

    Unit : ...........................

    TEMA type : ...............

    Exchanger ID numbers :.

    No. of bundles in parallel : ...........................

    No. of bundles in series : ..............................

    No. of bundles per unit : ...............................

    TUBES :

    Total No. of tubes : .........................

    No. of tubes per bundle : .........................

    No. of passes per bundle (tube side) : .........................

    Total No. of passes to be equipped : .........................

    Tube material / any Coating? : .........................

    Tube length : ......................... (m)

    Tube external diameter : ......................... (mm)

    BWG / tube thickness : .........................

    Tube internal diameter : ......................... (mm)

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    PROCESS CONDITIONS

    Process Data (TUBE SIDE):

    mini nominal maxi

    Total unit flow rate : ............ ............ ............ (t/h)

    Flow rate per bundle : ............ ............ ............ (t/h)

    Inlet temperature : ............ ............ ............ ( C)

    Outlet temperature : ............ ............ ............ ( C)Flow velocity : . .

    Process Data (SHELL SIDE):

    mini nominal maxi

    Total unit flow rate : ............ ............ ............ (t/h)

    Flow rate per bundle : ............ ............ ............ (t/h)

    Inlet temperature : ............ ............ ............ ( C)

    Outlet temperature : ............ ............ ............ ( C)

    Fluid nature : Tube side Shell side

    crude [ ] crude [ ]residue [ ] residue [ ]

    others (pls.indicate)[ ] ......... others [ ] .........

    Sediment in fluid : type/size ................... .

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    Page : 2/2QUESTIONNAIRE

    SPIRELF/TURBOTAL/FIXOTAL EVALUATION AND DESIGN

    Properties at average process temperature conditions :

    average temperature of the fluid in the tubes : ................ ( C)

    fluid condition : sensible [ ], condensing [ ] or boiling [ ]

    weight fraction vapor (in/out) : ............................................ (%)

    liquid vapor

    density at : T1 C: .................... .................... (kg/m3)

    density at : T2 C: .................... .................... (kg/m3)

    viscosity at : T1 C: .................... .................... (mPa.s)

    viscosity at : T2 C: .................... .................... (mPa.s)

    Pressure drop without TURBOTAL/FIXOTAL/SPIRELF :

    at the beginning of the run : .................... (kg/cm2)

    at the end of the run : .................... (kg/cm2)

    Maximum Pressure drop allowable: . (kg/cm2)

    Frequency of cleanings :

    chemical cleaning : ....................

    mechanical cleaning : ....................

    Fouling resistance :

    beginning of the run : .................... (m2. K/W)

    end of the run : .................... (m2. K/W)

    Fouling nature : soft [ ]

    hard [ ]

    other information : ...................

    Note: Please send a PFD of the preheat train, or a sketch of the exchangerarrangement).

    Please return this questionnaire to : P E T R O V A L9 rue de lEglise - BP 66

    Les Trois Pierres

    76430 ST-ROMAIN DE COLBOSC/ FRANCE

    : (33) 02 35 31 00 00 Fax: (33) 02 35 31 35 35 e-mail : petroval@petroval.com

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    Copy to:

    US representative: Artur W. Krueger, P.O.Box 19686, Houston, TX 77224-9686

    Tel: 001 713 464 8711; Fax: 001 713 464 8798; e-mail : artur.krueger@gmail.com

    Page : 1/2QUESTIONNAIRE

    SPIRELF/TURBOTAL/FIXOTAL EVALUATION AND DESIGN

    This evaluation is related to the exchanger to be equipped, therefore the

    following information is required :

    Customer : ...................

    Location : ....................

    Unit : ...........................

    TEMA type : ...............

    Exchanger ID numbers :.

    No. of bundles in parallel : ...........................

    No. of bundles in series : ..............................

    No. of bundles per unit : ...............................

    TUBES :Total No. of tubes : .........................

    No. of tubes per bundle : .........................

    No. of passes per bundle (tube side) : .........................

    Total No. of passes to be equipped : .........................

    Tube material / any Coating? : .........................

    Tube length : ......................... (m)

    Tube external diameter : ......................... (mm)

    BWG / tube thickness : .........................

    Tube internal diameter : ......................... (mm)

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    PROCESS CONDITIONS

    Process Data (TUBE SIDE):

    mini nominal maxi

    Total unit flow rate : ............ ............ ............ (t/h)

    Flow rate per bundle : ............ ............ ............ (t/h)

    Inlet temperature : ............ ............ ............ ( C)

    Outlet temperature : ............ ............ ............ ( C)Flow velocity : . .

    Process Data (SHELL SIDE):

    mini nominal maxi

    Total unit flow rate : ............ ............ ............ (t/h)

    Flow rate per bundle : ............ ............ ............ (t/h)

    Inlet temperature : ............ ............ ............ ( C)

    Outlet temperature : ............ ............ ............ ( C)

    Fluid nature : Tube side Shell side

    crude [ ] crude [ ]residue [ ] residue [ ]

    others (pls.indicate)[ ] ......... others [ ] .........

    Sediment in fluid : type/size ................... .

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    Page : 2/2QUESTIONNAIRE

    SPIRELF/TURBOTAL/FIXOTAL EVALUATION AND DESIGN

    Properties at average process temperature conditions :

    average temperature of the fluid in the tubes : ................ ( C)

    fluid condition : sensible [ ], condensing [ ] or boiling [ ]

    weight fraction vapor (in/out) : ............................................ (%)

    liquid vapor

    density at : T1 C: .................... .................... (kg/m3)

    density at : T2 C: .................... .................... (kg/m3)

    viscosity at : T1 C: .................... .................... (mPa.s)

    viscosity at : T2 C: .................... .................... (mPa.s)

    Pressure drop without TURBOTAL/FIXOTAL/SPIRELF :

    at the beginning of the run : .................... (kg/cm2)

    at the end of the run : .................... (kg/cm2)

    Maximum Pressure drop allowable: . (kg/cm2)

    Frequency of cleanings :

    chemical cleaning : ....................

    mechanical cleaning : ....................

    Fouling resistance :

    beginning of the run : .................... (m2. K/W)

    end of the run : .................... (m2. K/W)

    Fouling nature : soft [ ]

    hard [ ]

    other information : ...................

    Note: Please send a PFD of the preheat train, or a sketch of the exchangerarrangement).

    Please return this questionnaire to : P E T R O V A L9 rue de lEglise - BP 66

    Les Trois Pierres

    76430 ST-ROMAIN DE COLBOSC/ FRANCE

    : (33) 02 35 31 00 00 Fax: (33) 02 35 31 35 35 e-mail : petroval@petroval.com

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    Copy to:

    US representative: Artur W. Krueger, P.O.Box 19686, Houston, TX 77224-9686

    Tel: 001 713 464 8711; Fax: 001 713 464 8798; e-mail : artur.krueger@gmail.com

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