Hairpin Heat Exchangers

KOCH HEAT TRANSFER COMPANY

HAIRPINHEAT EXCHANGERS

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The Process AdvantageHairpin heat exchangers utilize true counter-current flow. Unlike multi-pass shell-and-tube designs where correction factors are used to account for inefficiencies resulting from co-current passes, this process maximizes temperature differences between shellside and tubeside fluids. When a process calls for a temperature cross (hot fluid outlet temperature is below cold fluid outlet temperature), a hairpin heat exchanger is the most efficient design, with fewer sections and less surface area. Double-pipe heat exchangers utilize a single pipe-within-a-pipe design and are commonly used for high fouling services such as slurries where abrasive materials are present, and for smaller duties. Standard shell diameters range from 2” to 6”. Multi-tube heat exchangers are used for larger duties with standard designs for shell diameters up to 30” and surface areas in excess of 10,000 ft2 per section. BROWN FINTUBE® hairpin heat exchangers offer a variety of unique enhancement devices for different process conditions.

Shellside Enhancement Devices Longitudinal fintubes - Provide extended heat transfer surface with relatively low

resulting pressure drops. They can be cut-and-twisted or used in conjunction with peripheral baffles for further enhancement.

TWISTED TUBE® Technology - Simultaneously enhances both shellside and tubeside heat transfer rates. They are self-supporting and allow straight-through cleaning of the shellside, despite being on a triangular tube pitch. The risk of flow-induced vibration is eliminated with this design and shellside fouling is minimized due to the elimination of “dead” spots commonly found when traditional segmental baffles are utilized.

Low Pressure Drop LOK-BAFFLE™ Baffles - Act primarily as tube supports. These are used for high shellside flow rates, low allowable pressure drops, or when the shellside coefficient does not limit the overall heat transfer rate.

Segmental baffles - These are traditional baffles that can be used in conjunction with seal-strips.

CLOSER TEMPERATURE APPROACH

Tubeside

ShellsideCOUNTER CURRENT FLOW

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Tubeside Enhancement Devices

TWISTED TUBE® Bundles - Promote turbulence of the tubeside fluid. They are also used for vaporizing services and when tube inserts are not preferred.

Tube Inserts - BROWN FINTUBE® technology offers a variety of tube inserts, which maximize the heat transfer rates of viscous fluids. They are also used for vaporizing services.

HIGHER HEAT TRANSFER RATES

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Large Radius U-bends

The free-floating U-tube bundle compensates for the differential shell-tube expansion and eliminates the need for expansion joints or packed joints commonly used in shell-and-tube type heat exchangers. Large radius U-bends are easily cleaned with flexible shaft tube cleaners.

EFFICIENCY IN DESIGN

The Mechanical Advantage1. Separate tubesheets: Handle high temperature differences and cycling more effectively than shell-and-tube

exchangers.

2. Durable baffle cage construction: Welded to the tie rods without the need for “sleeves” or internal nuts.

3. Moveable support brackets: Allow shell expansion and contraction and eliminate the need for sliding plates commonly used for fixed supports. Brackets are slotted for anchor bolts on all four sides for flexibility in installation, and offer the ability to add sections in the future.

4. Patented closure technology: Suits specific design needs (see adjacent page for details).

5. Tubeside and shellside connections on the same end: Easy installation and piping.

6. No internal bolting!

7. Double-pipe exchangers: Use pipe in lieu of thin wall tubing to enhance integrity.

2

3

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Separated-Head Low Pressure Closure

Our separated-head closure uses independent tubeside and shellside flanges, bolting and gasketing. This closure is used for moderate pressures up to 1,300 psi (92 kg/cm2), cyclic service, high temperature differences, and/or for temperatures below -20°F (-28.8°C) or greater than 650°F (343°C).

TAPER-LOK® High Pressure Closure

Our TAPER-LOK® closure is typically used for high pressure up to 15,000 psi (1055 kg/cm2) applications. Like our separated-head, the TAPER-LOK® closure uses separate tubeside and shellside flanges, bolting and gasketing. The unique feature this closure offers is a reusable TAPER-LOK® ring which acts as a self-energizing seal. Koch Heat Transfer

Company has an exclusive license for TAPER-LOK® closures for use in double pipe and multi-tube hairpin heat exchangers.

LOK-FLANGE® Closure

The LOK-FLANGE® closure uses common through-bolting with independent gaskets and is typically used for design pressures below 1,000 psi (70 kg/cm2). The center flange of this closure is threaded, which allows removal of the tube-end flange for inspection and cleaning of the tubes while maintaining pressure on the shellside. This closure allows the maximum number of tubes in a given shell diameter.

ZR CLOSURE™ Closure

The ZR CLOSURE™ closure is the newest addition to the BROWN FINTUBE® family of closures. This closure bridges the gap between the separated-head and

the LOK-FLANGE® closure by providing separate tubeside and shellside flanging and bolting, while retaining the maximum number of tubes in a given shell diameter.

Return End Bonnet Closure

This closure is a conservative through-bolted design. When the bonnet is removed, the U-bends of the tubes are completely exposed to permit full field inspection.

Superior Closure Design

Our closure designs offer an effective means of providing a removable tube bundle for a variety of design conditions and applications. All of our closures have the following features:

External Split rings - Split rings are used to lock the bundle to the shell. On outdated models these rings were internal and came into contact with the shellside fluid. Internal split-rings are still used by others.

Through bolting - Earlier models used studded bolting that could seize or break off and are still used by other manufacturers.

Better gasketing - Unlike other manufacturers, our gaskets do not seat on the tubesheet face where misalignment easily can occur and the potential for erosion exists. Our shellside gaskets are easier to remove than wedge gasketing used by competitors.

Separate tubeside and shellside gaskets - Prevent interstream leakage.

Round flanges - More effective gasket seating than square flanges.

CONVENIENT ACCESSIBILITY

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Exemplary Hairpin Applications

When To Use BROWN FINTUBE® Hairpin Heat Exchangers

A hairpin heat exchanger should be considered when one or more of the following conditions exist:

The process results in a temperature cross.

High pressure tubeside application.

A low allowable pressure drop is required on one side.

Cyclic service.

High flowrate ratios between shellside and tubeside fluids.

High terminal temperature differences (300°F/149°C or greater).

When an augmentation device will enhance the heat transfer coefficient.

When the exchanger is subject to thermal shock.

When flow-induced vibration may be a problem.

When heating or cooling vapors.

When complete vaporization is required.

When solids are present in the process stream.

When the mechanical advantages of a hairpin are preferred.

Koch Heat Transfer Company Maintenance Support

Maintenance

Operation and maintenance manuals are available that address the disassembly and reassembly of specific designs. In general, the bundle of a hairpin exchanger is removed by first removing the tubeside bolting, flanges and split rings. The next step is to remove the shellside bolting, flanges and split rings. Finally, the return bonnet bolting is removed and the bonnet is placed to the side. The tube element can now be pulled from the back end of the shell by placing a sling around the U-bends. On larger multitubes, a plate is installed around the U-bend for proper sling placement. Assembly is performed by reversing the process and utilizing new gaskets.

Spare Parts

Replacement parts for BROWN FINTUBE® or BAS-TEX exchangers are readily available. One complete set of gaskets is recommended for one year’s operation.

Surveys

For facilities with numerous hairpin exchangers, Koch Heat Transfer Company will perform a survey of the facility and establish design equivalents to current BROWN FINTUBE® models. We will also evaluate ways to establish common designs for multiple services to allow commonality of spare parts and elements, resulting in reduced spare parts inventories and maintenance. Please contact a Koch Heat Transfer Company sales representative for more details.

VARIETY OF SOLUTIONS

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BROWN FINTUBE® is registered in the U.S. and other countries worldwide.

TWISTED TUBE® is registered in the U.S. and other countries worldwide.

LOK-FLANGE® is registered in the U.S.

Koch Heat Transfer Company is the sole supplier of BROWN FINTUBE® products.

TAPER-LOK® is a registered trademark of Taper-Lok Corporation.

Lummus Advanced Breech-Lock Exchanger™ is a registered trademark of Lummus Technology Heat Transfer.

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www.kochheattransfer.com

Email : [email protected]

For more information about our products and locations,please visit our website

KOCH HEAT TRANSFER COMPANY

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THE ONLY SOURCE YOU WILL NEED FOR HEAT TRANSFER SOLUTIONS.

Our thermal engineers rely on the Koch Heat Transfer Company state-of-the-art technologies to develop the best possible solutions for our customers’ applications. From research and development through thermal and mechanical design, best-in-class manufacturing, technical assistance and aftermarket service, our engineers help you optimize your heat transfer systems to make your operations more efficient and productive.

TWISTED TUBE®

EXCHANGERS

BROWN FINTUBE®

HAIRPIN EXCHANGERS

FINTUBETECHNOLOGY

LOK-BAFFLE™ LOW PRESSUREDROP BAFFLES

GLOBALMANUFACTURING

GLOBALSOURCING

TUBESIDEAUGMENTATION

TAPER-LOK®

CLOSURE

BREECH-LOCK™

CLOSURE

FLOW MODIFICATIONTECHNOLOGY

KOCH HEAT TRANSFER COMPANY

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