HeliFlow Heat Exchangers

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1 HeliFlow Heat Exchangers The Graham Heliflow Heat Exchanger is uniquely designed and engineered to handle difficult heat transfer applications. Graham created the Heliflow to be exceptionally versatile, yielding heat transfer rates that can be more than 40% better than typical shell and tube designs. The Heliflow Heat Exchanger encompasses a spiral coil, comprised of multiple parallel tubes mounted within a casing. The case/coil construction creates a spiral flow path providing true counter flow. Each application is specially engineered for an optimal balance of thermal and hydraulic requirements, resulting in maximum heat transfer efficiency. High pressure, specialized materials, cyclic operation, temperature extremes and other conditions can be handled without a problem. The Graham Heliflow Heat Exchanger has years of proven service, in thousands of applications throughout the world, with high quality performance always guaranteed. The tubes in the Heliflow are arranged in parallel, starting with an inlet manifold on one end, and terminating at an outlet manifold on the opposite end. The tube bundle is wound into a helical pattern. This coiled construction creates a spiral flow path for the fluid inside the coil. Each tube is in close contact with the tube above and below it. The coiled tube bundle is fit into a two-piece casing. When the casing is tightened, it is designed to slightly compress the tubes. Because of the tight fit, the shell side fluid is forced to circulate in a spiral pattern created by the open spaces between the coils. Advantages of Graham Heliflow Spiral Tube Heat Exchangers Higher efficiency Easy to maintain Accommodates pressures up to 15,000 psig High reliability Code compliant Easily customized Low flow rates Compact design Withstands 500 deg. F temperature difference between fluids Varied material choices

2 The many advantages of the unique Graham Heliflow make it an efficient heat exchanger for a wide range of applications; some of which include: Liquid-to-liquid Cryogenic High pressure Clean steam generators Blowdown Natural gas heaters Vent condensers Mechanical seal coolers Compressor inter/aftercoolers Supercritical fluid Feedwater preheaters Lethal service Steam or process fluid vaporizers Boiler or process sample coolers Hot water heaters High temperature Freeze condensers Hydraulic/lube oil coolers Liquid-to-liquid The Graham Heliflow is ideally suited for applications that have a liquid-to-liquid service requiring a heat exchanger. When designing the exchanger, the "dirty" fluid should be on the shell side of the unit. The Heliflow makes shell side cleaning easy. Cleaning can be done in-place, without breaking shell side or tube side pipe connections. The flow pattern is 100% countercurrent that maximizes the temperature differential and thermal efficiency. Cryogenic Graham has conducted extensive research and development in the area of cryogenic vaporizers. Our research and many years of proven experience in this area confirm that the Heliflow heat exchanger is excellent for cryogenic applications. The unique tube coil of the Heliflow can easily accommodate the large temperature differentials that are typical in cryogenic units.

3 Heliflow Heat Exchangers often use cryogenic fluids as the cooling medium; alternately, Heliflows can be used to vaporize fluids, such as N2, O2, CO2, or other fluids. For information on this subject, refer to the Graham article titled Convective flow boiling in coiled tubes. High pressure High pressure applications are another way to utilize the Heliflow Heat Exchanger. The tube side of the exchanger does not rely on gaskets for sealing, and can be designed to 15,000 psig. A key advantage that a Heliflow offers is that it has no flat sided pressure bearing surfaces that quickly become thick as design pressure increases. A Heliflow uses tubing and pipe to contain the tube side's usually high operating pressure fluid. The shell side of the unit can be rated for pressures up to 5,000 psig. Clean steam generators The Graham Heliflow meets the need for clean, chemical-free steam. This technology has been developed over the past 60 years to take advantage of the Heliflow coiled tube geometry. The stacked tube layout eliminates problems caused by thermal expansion and cycling. In addition, this design promotes nucleate boiling, resulting in superior heat transfer efficiency. The Graham Clean Steam Generator is designed to produce clean, chemical-free steam from clean feed water, using plant steam as the energy source. Blowdown Boiler blowdown and process sample coolers are perfect applications for a Heliflow heat exchanger. The compact size of the Heliflow fits into tight spaces. Also, the Heliflow design can withstand the cyclic nature of blowdown service. Natural gas heaters When natural gas is passed through a pressure reducing station, it decreases in temperature. The compact Heliflow design is often used to increase the temperature of the natural gas.

4 Vent condensers Heliflow Heat Exchanger technology is at the heart of Graham's vent condensers. Vent condensers are often used on storage tanks to reclaim products contained in the tank and control the harmful emissions that escape from the tank to atmosphere. During the day, the sun heats the fluid in the tank. The increase in the system's temperature will cause the vapors in the tank to expand and increase vaporization of the volatile components as their vapor pressures increase. By installing a vent condenser on the vessel, the condensable vapors are reclaimed and refluxed back into the storage tank. In addition to the venting caused by temperature changes, vapors are exhausted to atmosphere as the tank is filled. The vent condenser experiences the greatest thermal duty when the tank is being filled. The heat exchanger, therefore, should be sized based on the filling case. Graham has taken the lead in reducing VOC (volatile organic compound) emissions with our design of specialized vent condensers. These units often are used to recover valuable product and reduce the load on downstream pollution control equipment at the same time. Three styles are available for your choosing: VCIN No casing required, most economical choice Typically used for new vessels Drop tube can be supplied to reflux condensate below liquid level Fits inside a flanged vessel connection

5 VCON Typically used on existing vessels Does not require additional supporting structure Mounts on top of flanged vessel connection VCT Corrosive fluid can be placed on the tubeside Casing can be lower cost material Permits sub-cooling of the condensate

6 Mechanical seal coolers Keeping the mechanical seal faces cool is extremely important in extending the operating life of mechanical seals. The unique design of the Graham Heliflow facilitates superior cooling of the seal flush fluid as compared to traditional mechanical seal coolers. Heliflow seal coolers can be fitted with vent connections which enable the units to meet the venting and draining requirements of API 682. In addition, Heliflow seal coolers have the ability to thermosiphon in the event of a pumping ring failure. API flush plans 21 or 23 are the common arrangements for configuring mechanical seal cooling systems. In Plan 21, the product from the pump discharge is circulated through a valve or orifice and then flows through a Heliflow seal cooler where it is cooled before returning to the mechanical seals. In API Plan 23, the product is recirculated from the stuffing box through the Heliflow and then back to the mechanical seal. Standard models are available in 316 stainless steel tube side and cast iron shell. Options include 304 stainless steel, titanium, 70/30 cu.ni. tubes, 316 stainless steel and cast steel shell materials. Units can also be constructed to ASME Section VIII, Division 1 Code if desired. Sizing software is available from Graham to assist in selecting units for both API Plans 21 and 23. Standard Heliflow units do not conform with the tubing recommendations of API 682, however, specially designed units are available, which include 3/4" diameter x.095" wall thickness tubes to provide complete compliance with the standard. Compressor inter/aftercoolers Heliflow Heat Exchangers are preferred for high pressure service, and are often used as inter and aftercoolers to cool the gases handled by reciprocating type compressors. Typical design pressure is psig, however, units designed for up to 15,000 psig are available. Graham has extensive experience in engineering, design, and fabrication of units for compressor service. Supercritical fluid Supercritical water oxidation (SCWO) is a cutting edge technology developed for the treatment of hazardous waste solutions. This method uses high pressure, high temperature water at its supercritical state of 3200 psig and 705 degrees F. During

7 this process, oxygen and the supercritical water are injected into the waste stream. The waste contaminants are oxidized, transforming them into carbon dioxide and other harmless substances. This process is cost competitive and more environmentally friendly than traditional disposal methods, such as landfill or incineration. Specially designed Heliflow Heat Exchangers with spherical casings are used to withstand the high operating pressures and temperatures required. These units are used to cool the reactor effluent, to generate steam, as a feed interchanger, and as sample coolers. Feedwater preheaters Heliflow Heat Exchangers can save energy as heat recovery economizers. Waste heat is recovered and utilized to preheat incoming make-up water that is used in boilers or for other applications. Lethal service Specially designed Heliflow Heat Exchangers are available for use when handling lethal liquids or vapors. These units are built to strict manufacturing, welding, and quality control specifications and include specially developed features to provide confidence when handling lethal fluids. Steam or process fluid vaporizers The Heliflow Heat Exchanger design is often used to provide a compact vaporizer. The coiled tube bundle promotes nucleate boiling, and can easily handle the stresses caused by thermal expansion and cycling. Steam or other high temperature sources are often used to vaporize nitrogen, oxygen, carbon dioxide, hydrogen, methane, ethylene, various hydrocarbons, and many other fluids. Vaporizing can be achieved either shellside or tubeside according to process requirements. Boiler or process sample coolers The compact footprint of the Heliflow Heat Exchanger, along with its ability to handle frequent cycling and wide temperature differentials make this unit ideal for use in sample cooler applications.

8 Hot water heaters Heliflow Heat Exchangers can heat water using steam or high temperature hot water (or other fluids) as the energy source. When control of the water temperature is important, temperature control valves are often used with the Heliflow design. If the water flow rate varies, and outlet temperature must be controlled, Graham offers our packaged MicroMix II instantaneous, steam-fired, hot water heaters. High temperature A benefit of Heliflow Heat Exchangers at higher temperatures is the ability of the coil to flex as it is heated. As the tubes are heated, they grow due to thermal expansion. Because the Heliflow bundle is free to move, the units can undergo many years of cyclic operation without problem. A major drawback for many other types of exchangers is reduced operating life when working at higher temperatures, or the exchanger must include expensive expansion joints. A Heliflow Heat Exchanger is the best choice for high temperature applications. Freeze condensers Freeze condensers fall into two categories; the first includes vapors that condense, then freeze in the heat exchanger. The second category typically includes nonfreezing condensables mixed with water vapor or another component, which does freeze. Both applications are similar in that the objective is to condense and remove from the vent stream as much of the vapor component as possible. The most effective method is to cool the vapor below its freezing point, however, once a component begins to freeze, the heat transfer rate is gradually decreased. To obtain the best efficiency, often two parallel units are used. One unit operates, while the other undergoes a thaw cycle. Graham is uniquely experienced in the field of freeze condenser technology. Our Heliflow Heat Exchangers can be provided based on system requirements. Years of experience and numerous research projects enable Graham to provide "Engineering Answers" tailored to specific applications. Hydraulic/lube oil coolers The coiled tube geometry of the Heliflow Heat Exchanger provides increased heat transfer efficiency, making these units ideal for use as oil coolers.

9 HEAT EXCHANGERS Simple The optimum heat exchanger as: Vent Condensers Reboilers/Vaporizers Liquefied Gas Vaporizers Process Condensers High Pressure Exchangers Hydraulic/Lube Oil Coolers High Temperature Exchangers Cryogenic Exchangers Compressor Inter/After Coolers Sample Coolers Hot Water Heaters Compact design 1 to 650 sq.ft. Versatile High efficiency

10 Graham Corporation a world leader. Graham Corporation is a leader in heat transfer and vacuum equipment used worldwide in the process, power, marine, and commercial industries. We offer complete single-source reliability with our in-house research and development, design engineering, manufacturing and testing facilities plus a worldwide sales force. We guarantee the performance of our Heliflow Heat Exchangers, Plate Heat Exchangers, MicroMix II Water Heaters, Steam Surface Condensers, Steam Jet Ejectors, Steam Vacuum Refrigeration, Liquid Ring Vacuum Pumps, Fume Scrubbers, Desuperheaters, and Atmospheric Relief Valves. We build to the highest quality standards and the world s most exacting codes. Graham is headquartered in Batavia, New York, has another plant in Great Britain, and associated fabricators worldwide. HEAT EXCHANGERS Exclusive, state-of-the-art design. A unique design that makes HELIFLOW Heat Exchangers exceptionally compact, strong, efficient, reliable, versatile, and able to handle a wide range of flow, pressure and temperature requirements. They have had years of proven service in thousands of applications throughout the world, with high quality performance always guaranteed. Simplicity. The Heliflow encompasses a spiral coil, comprised of multiple parallel tubes mounted within a casing and baseplate. The case/coil construction creates a spiral flow path for both the fluid inside and outside of the tube coil, providing true counterflow. An accurate, constant velocity is maintained. Coil spacing between tubes may be varied for an optimal balance of thermal and hydraulic requirements. This provides maximum, more consistent heat transfer efficiency. COMPACT, LIGHTWEIGHT VERSATILITY: Heliflows function in any position up, down, sideways, or in between in a fraction of the space of typical shell and tube exchangers. Mount on columns, nozzles, engines, walls, ceilings, or in-line without additional support. A Heliflow can fit where others can t, with no draining problem. HIGH EFFICIENCY: True counter- flow and improved heat transfer rates allow heat exchange up to 40% greater than comparable shell and tube designs. Close temperature approach can be maintained even with temperatures crossed. No baffles or sharp turns can interrupt flow velocity. No matter how small the design rate of flow, correct velocity can be designed and maintained. BROAD CAPABILITIES: The Heliflow Heat Exchanger with its spring-like coils, absorbs mechanical and thermal stresses, minimizing strain on the tube connections. This feature enables the Heliflow to operate in pressure services exceeding 10,000 psig, and temperature gradients of 500 F between the two fluids. SIMPLE RELIABILITY: Heliflow s design, simplicity, and strength enhance its performance, reliability and lasting value. It s more trouble-free. Coils can be cleaned or changed easily. There s less maintenance and downtime. COST SAVINGS: Considerable time and money are saved due to Heliflow s simple, compact, light-weight, versatile, and trouble-free design and their ease of installation and maintenance. WIDE CHOICES: Heliflows are readily available in 80 standard models. Heat transfer surfaces can range from 1 to 650 sq. ft. EASILY CUSTOMIZED: For special, unique or lethal applications, Graham can custom-design Heliflows in a wide range of designs, construction codes and materials, including non-ferrous, stainless steel, titanium, and many high-nickel and specialty alloys.

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12 Standard or Customized Thousands of GRAHAM HELIFLOW Heat Exchangers have been in service for years throughout the world. High-pressure, high-temperature Heliflow s unique coil design allows it to operate under extremes of both pressure and temperature. Due to this proven capability, Heliflows are frequently used as: Vent Condensers Sample Coolers Hot Water Heaters Reboilers/Vaporizers Process Condensers Liquefied Gas Vaporizers High Pressure Exchangers Hydraulic/Lube Oil Coolers High Temperature Exchangers Cryogenic Exchangers Compressor Inter/After Coolers Seal Coolers HELIFLOW OPERATION The simple logic of heat transfer. The unique spiral coil design provides a constant flow pattern with uninterrupted velocity throughout the entire flow path around and through each tube. This assures maximum heat transfer efficiencies. Vent Condensers Heliflow s unique, compact features make it ideal for vent condensing applications. With simple design modifications, it s ideal for: internal or external mounting condensate return, recovery or removal solvent recovery overcoming environmental concerns Sample Coolers Heliflows have long demonstrated their ability to meet the demands of: extreme temperature and pressure variations low flow, and on/off or continuous operation Instantaneous Water Heaters Heliflow s compactness and high efficiency make it an ideal heat exchanger for the GRAHAM Micro- Mix II steam-water heater. High output capacities are achieved using less than 6 sq. ft. of floor space. Heating and Cooling Heliflows are well-proven as compact, economical designs ideal for most industrial heat exchanger needs extensively used for: pharmaceuticals, paints, solvents, organics, acids, oils, heat transfer fluids, gases, steam, etc. Vaporizers Heliflows have proven to be superior vaporizers extensively used for vaporization of deionized water, aqueous solutions, ammonia, nitrogen, oxygen, liquefied gases, and solvents using steam, water, solvents, glycols and heat transfer fluids as the heating medium. Pressure Gauge HEAT EXCHANGERS Cryogenic Coolers The Heliflow s ability to absorb thermal stresses proves ideal in low-temperature operation. Heliflows can utilize the vaporization of liquefied gases, refrigerants or other cryogenic fluids of sub-zero cooling of process fluids, solvent recovery, vent gas condensation, and other lowtemperature industrial cooling operations. Interchangers The Heliflow s spiral coil design provides for temperature extremes. Heat recovery efficiencies are maximized and many process applications including oil reprocessing, heat transfer fluid systems, and others where extremes of temperature are frequently encountered. Pure/Deionized Steam Generators Heliflows can use boiler steam to produce pure, uncontaminated water vapor for humidification systems and other processes requiring chemically pure steam. Process Condensers The Heliflow s reverse and through manifold design provides a condenser of multiple orientation, utilization, compactness, and an ideal condensing surface for: reflux condensing, solvent recovery condensation and separation of condensibles from noncondensibles Pump Seal Coolers Mechanical seals used on mediumand high-temperature pumps require that the seal fluid be cooled to ensure proper seal operation. Heliflows provide this cooling efficiently, economically, and in less space. Hot Process Out Steam In Cold Process In Steam and Condensate Out

13 Bare Tube Heliflow For heat transfer from one fluid to another. Unique design includes a spiral coil (in commercially available tube materials from ¼ to ¾ diameter) mounted within a casing and baseplate. Components are oriented so the casing/coil configuration creates a spiral flow path for the fluid outside the coil, which flows counter to the fluid inside the coil. There are no inactive areas. With the spiral coil design, dead spaces do not exist and an accurate, constant velocity is maintained throughout the path of flow through and around each coil. The coil spacing between the tubes can be varied to provide specific fluid velocities for the fluid outside the coil, optimizing heat transfer and pressure drop. An outstanding feature is the inherent strength of the manifold design. With the elimination of the typical tube sheet and bonnet construction, the Heliflow heat exchanger economically provides for extremes of pressure and temperature. Custom Heliflows Guaranteed to meet specifications for any unique, special or lethal applications. Our wide range of standard Heliflows are available in most commercial tube materials to satisfy 90 percent of industry s pressures to 7,500 psig. Special design can accommodate design pressure to at least 10,000 psig. Multi-pass tube side, reverse and through manifolds, special fittings, pipe connections and other special arrangements are available. Vented Double-Wall Heliflows Ideal for detection and prevention of cross contamination. This vented, double-wall and double-manifold tube-ina-tube design has a vented pathway between the hot and cold fluids. High thermal efficiency is maintained while providing protection and detection against cross contamination. Ideal where process purity is mandatory and when required by state and local regulations for the protection of domestic and potable waters. Static Mixer Heliflows For high-viscosity fluids, the Heliflow s efficiency is enhanced by use of static mixers. Elements in each tube increase fluid mixing and maximize heat transfer, thereby reducing the required surface area. Polished Tube Heliflows All internal surfaces are highly polished. This makes it an ideal exchanger for applications requiring clean heat transfer pharmaceutical, computer/ electronics, deionized water and other clean operations. Replacements and Shipments No Graham product ever becomes an orphan. Replacement parts and assistance are always available. Anywhere. Parts and complete standard units are available off-the-shelf. And a stock of finished and semi-finished parts for special sizes are always available. Prompt shipment is assured. And we airfreight to any part of the world when necessary. More Information A Heliflow Operation & Maintenance Manual is available on request. It contains detailed instructions on how to best install, operate, and maintain Heliflows for optimum and lasting heat transfer. It also includes tips to speed up disassembly and re-assembly. For a free copy, see your Graham representative or contact Graham Corporation.

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15 HELIFLOW CONSTRUCTION Simple reliability 1. Base Plate Nuts secure the single flanged joint. Typical shell and tube units have four such joints. 2. Heavy-duty Manifold Holding Nuts and locking rings tightly secure both manifolds to hold the coil assembly to the base plate. 3. Gaskets insure tightly sealed joint between manifold and base plate. 4. Upper and Lower Manifold precision-made for rigid, heavy-duty performance. 5. Coil Manifold Assembly precision-built to assure high heat transfer efficiency, 100% effective counterflow, and more trouble-free performance. 6. Single-piece Gasket available in any material that best meets operating conditions. 7. Heavy-Duty Casing Studs for high-pressure reliability. 8. One-Piece Casing can be removed for easy cleaning without breaking any pipe connections. 9. Threaded Vent and Drain Plugs designed and located for easy use and access. 10.Support Bracket can be placed in several positions for convenience. MAINTENANCE & SERVICE Reliable simplicity Cleaning a Heliflow is as simple as its construction. No special tools or fixtures are required. It takes only 1/4 th the time, and there is little or no risk of damage compared to cleaning requirements for straight-tube exchangers. Operation is based on the premise that the fluid circulating in the casing will have fouling tendencies, while the fluid circulating inside the coils is cleaner. If the fluid inside the coils eventually fouls, and chemical cleaning cannot be used, replacing coils is fast and easy. The outside of the coils can be inspected and cleaned easily by removing the casing. To disassemble, follow these steps: A. Disconnect all pipes. B. Remove all base plate nuts. C. Separate the case from the base, being careful not to damage the casing gasket. D. Remove manifold holding nuts. Remove the integral manifolds and coil assembly from the base plate. E. When re-assembling, remember the spark plug type gaskets between the manifold collars and the base plate and the lock rings between the manifold nuts and base plate. These locking nuts prevent manifolds from turning when pulling up gaskets and re-piping. HEAT EXCHANGERS Graham designed, manufactured, tested and guaranteed. A Real Graham Advantage.

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