BOS-HATTEN™ Heat Exchangers
Custom designed Shell & Tube Heat Exchangers for your specific needs. Some of the most common applications include:
- Kettle Reboilers
- Fuel Gas Heaters
- Rotor Air Coolers
- Compressor Intercoolers & Aftercoolers (with or without separators)
- Falling Film Evaporators
- Thermosyphon Reboilers
- Feedwater heaters (Single or Multizone)
- General Service Condensers
- Oil Coolers
- Suction Heaters
- Plate Fin
- Steam Surface Condensers
As with all BOS-HATTEN™ units, both thermal and mechanical guarantees are provided. Units are designed to ASME Section VIII, Div 1, API specifications, and customer supplied specifications.
Kettle reboilers are used in services where 20% to 100% boil-up is required. Then enlarged outer shell provides a separation between the boiling fluid and the exit nozzle reducing the amount of liquid entrainement in the exiting vapor stream. In cases where the amount of liquid entrainment must be minimal, BOS-HATTEN™ can provide a unit with demister pad inside the shell. In lieu of providing a larger diameter shell, a separate tank, bolted or welded to the top of the exchanger, for vapor/liquid separation can be supplied
Fuel Gas Heaters
Fuel gas heaters are designed to heat natural gas streams with feedwater (the most common medium) or steam. Design pressures for the natural gas stream range from as low as 20 psi to over 2000 psi. A temperature cross between the natural gas and water is common. In these instances, the most efficient design is often a TEMA type CFU or BFU with an insulated longitudinal baffle. The most common construction material is carbon steel with the tubes constructed either of carbon steel or stainless steel. Other materials are certainly available. See our Fuel Gas Conditioning Systems.
Rotor Air Coolers
Rotor air coolers are used in the power generation industry and are designed to cool hot air and generate steam. The hot air is a by-product created from air used to cool the fuel gas turbine. The heat in the air stream is removed and used to generate steam. The cooled air is returned to the turbine.
Hot air passes through the tube side while steam is generated on the shell side. The air may be cooled utilizing either just a LP (low pressure) steam generator or a two step process with both a IP(intermediate pressure) and LP steam generator. When two exchangers in series are utilized, the exchangers can either be completely separate and piped in the field by the customer, or bolted together to minimize piping and pressure drop. The shell side is carbon steel, tubes are generally SS304, and the tube side is either SS304 or chrome moly
Compressor Intercoolers & Aftercoolers
As the workhorse for compressor interstage cooling, these units can be supplied as either straight tube or U-Tube units featuring either a removable or non-removable bundle. These units have been supplied in services ranging from vacuum conditions to over 4000 psi with the gas on either the shell side or the tube side. In addition, BOS-HATTEN™ regularly provides intercoolers for oxygen service using our oxygen cleaning procedures accepted by industry leaders in oxygen manufacturing. BOS-HATTEN™ can also supply separator technology to remove condensate from the gas stream using either a T-Type separator, an internal tuyere or other separation technology.
Falling Film Evaporators
Falling film evaporators are typically used as reboilers for distillation columns. Liquid enters the unit at the top and boils inside the tubes with a film of liquid developed around the inside periphery of the tube. When designing these units, the BOS-HATTEN™ staff works closely with both the customer and HTRI to ensure that the unit is designed specifically to the needs of the customer. Our experienced design staff will ensure that the inlet bonnet is properly designed to provide equal distribution of the liquid across the tube bundle, ensuring a proper film of liquid is developed in each of the tubes. This ensures proper pressure drop and heat transfer on the tubeside. These units have been supplied in the sizes ranging from 20" and below to 100" in diameter.
Thermosyphon Reboilers are generally heat exchangers used to provide vapor boil-up to a distillation column. they can be provided in either a vertical position (generally as a TEMA type BEM or NEN) with the boiling fluid in the tubes or in the horizontal position (with a TEMA Type "H" shell) featuring the boiling fluid in the shell side. In normal operation, between 10% and 33% of the liquid entering the unit is boiled.
Feedwater Heater & Spray Water Condensers
Rugged and durable, the feedwater heater is used in power applications typically in the boiler system. Feedwater heaters are available in single zone (condensing only), two zone (condensing and subcooling), and three zone (desuperheating, condensing and subcooling). Design pressure can be handled from atmospheric to 5000psi. Units can be supplied vertically or horizontally and are designed using HEI practices. Sizes can range from table top to 6 foot diameter or larger. The spray water condenser is a single zone unit used to provide hot water for attemperation to the boiler. This attemperation water is used to control the boiling rate in the boiler. This product is used in a wide variety of boiler systems.
General Service Condensers
BOS-HATTEN™ can design units for all cases where condensing is required. From large overhead condensers for distillation colums to knock-out condensers designed to remove a small amount of condensate from a gas steam, BOS-HATTEN™ can provide the right design for your needs. The condensing medium can be placed on either the shell side or the tube side. For condensing a mixture of components, BOS-HATTEN™ employs PPDS to obtain vapor liquid equilibrium data and physical properties. From that data, we can properly calculate a MTD (mean temperature difference).
From standard to highly specialized, these units come in a full range of sizes and materials available from BOS-HATTEN™. These units are usually specified as floating head (TEMA type "W") with O-Ring and weep hole for early leak detection.
Suction heaters are designed to be bolted directly into a storage tank through a manway or large flange. The most common application is for oil tank heaters using all carbon steel construction, however they are available in a full range of materials of construction and designs. A tube bundle, with a partial shell, is inserted into the tank. The heating medium (generally steam) is run through the tubes. The tank contents are heated as they are pumped out of the tank. This heating reduces viscosity and flow properties to reduce pump power
Plate Fin Heat Exchangers
The plate fin is a unique device that is used in centrifugal and axial compressor applications. These units have special aluminum high fins that have admiralty or copper-nickel tubes expanded into these fins. The plate fin is typically used for air or nitrogen gases at high volume flow rates and low pressures. The plate fin design allows for maximum support of the tube that prevents vibration problems that would occur in standard shell & tube units. The fin also provides a large effective surface area that is required for gas coolers due to their low heat transfer coefficients. These units can be designed with a mesh pad separator, a perforated plate or other separation technology for moisture knock out.
Dual Diameter Steam Surface Condensers
When you bring BOS-HATTEN™ Dual Diameter Condensers into your turbine system, you're introducing a combination of design efficiency, high quality engineering, and experienced manufacturing ability to your operations. You'll be giving your turbine installation a reliable, long-lasting partner.
The central air-cooling section draws steam and non-condensables uniformly through the bundle. This eliminates stagnant areas of poor heat transfer and high corrosion. The large air gathering section allows non-condensables to flow to a common air-offtake with minimal pressure drop. The design maintains uniform condensing pressure and temperature along the length of the bundle. Proper steam distribution is maintained. The eccentric bundle assembly allows maximum steam penetration along and around the bundle. This reduces pressure drop, and increases thermal efficiency.
For the best possible heat transfer properties, BOS-HATTEN™ can apply one of three tools (turbulators, finned tubes, or baffles) to improve the efficiency of our exchangers. This gives you the best performance in the most economical package.
Tube-side Heat Transfer Augmentation
Laminar Flow Condition
Tube-sheet side heat transfer coefficient is controlling. 100% vaporization on tube side required.
Used when shell-side heat transfer coefficient is controlling (2 types):
- Higher heat transfer coefficient
- Higher pressure drop
- Medium heat transfer coefficient
- Medium pressure drop
- Lower heat transfer coefficient
- Lower pressure drop