Considerations in Selecting Industrial Heat Exchangers

Standard-Xchange


The information below, courtesy of Standard-Xchange, outlines various design types of heat exchangers along with their advantages, limitations, and selection tips. For more information on applying heat exchangers to industrial process, contact Mountain States Engineering and Controls.

Non-Removable Bundle, Fixed Tubesheet

Advantages
  • Less costly than removable bundle heat exchangers
  • Provides maximum heat transfer surface per given shell and tube size
  • Provides multi-tube pass arrangements
  • Interchangeable with competitive models
Limitations
  • Shell side can be cleaned only by chemical means
  • No provisions to correct for differential thermal expansion between the shell and tubes. (Exception: expansion joint, available only on C200 and C210 exchangers)
Selection Tips
  • For lube and oil and hydraulic oil coolers, put the oil through the shell side
  • Corrosive or high fouling fluids should be put through the tube side
  • In general, put the coldest fluid through the tube side

Removable Bundle, Packed Floating Tubesheet

Advantages
  • Floating end allows for differential thermal expansion between the shell and tubes
  • Shell side can be steam or mechanically cleaned
  • Bundle can be easily repaired or replaced
  • Less costly than full interval floating head-type construction
  • Maximum surface per given shell and tube size for removable bundle designs
Limitations
  • Shell side fluids limited to non-volatile and/or non-toxic fluids, i.e., lube oils, hydraulic oils
  • Tube side arrangements limited to one or two passes Tubes expand as a group, not individually (as in U-tube unit); therefore, sudden shocking should be avoided
  • Packing limits design pressure and temperature
Selection Tips
  • For lube oil and hydraulic oil coolers, put the oil through the shell side
  • For air intercoolers and aftercoolers on compressors, put air through the tube side
  • Coolers with water through the tube side: clean or jacket water, use 3/8” tubes; raw water, use 5/8” or 3/4” tubes
  • Put hot shell side fluid through at stationary end (to keep temperature of packing as low as possible)

Removable Bundle, Pull-Through Bolted Internal Floating Head Cover

Advantages
  • Allows for differential thermal expansion between the shell and tubes
  • Bundle can be removed from shell for cleaning
  • or repairing, without removing the floating head cover
  • Provides multi-tube pass arrangements
  • Provides large bundle entrance area
  • Excellent for handling flammable and/or toxic fluids
Limitations
  • For given set of conditions, it is the most costly of all the basic types of heat exchanger designs
  • Less surface per given shell and tube size than C500
  • Selection Tips
  • If possible, put the fluid with the lowest heat transfer coefficient through the shell side
  • If possible, put the fluid with the highest working pressure through the tube side
  • If possible, put the high fouling fluid through the tube side

Removable Bundle, Internal Clamp Ring-Type Floating Head Cover

Advantages
  • Allows for differential thermal expansion between the shell and tubes
  • Excellent for handling flammable and/or toxic fluids
  • Provides multi-tube pass arrangements
Limitations
  • Shell cover, clamp-ring and gloating head cover must be removed prior to removing the bundle.
  • More costly than fixed tube sheet or U-tube heat exchanger designs
Selection Tips
  • If possible, put the fluid with the lowest heat transfer coefficient through the shell side
  • If possible, put the fluid with the highest working pressure through the tube side
  • If possible, put the high fouling fluid through the tube side

Removable Bundle, U-Tube

Advantages
  • Less costly than floating head or packing floating tubesheet designs
  • Provides multi-tube pass arrangements
  • Allows for differential thermal expansion between the shell and tubes, as well as between individual tubes
  • High surface per given shell and tube size
  • Capable of withstanding thermal shock
Limitations
  • Tube side can be cleaned only by chemical means
  • Individual tube replacement is difficult
  • Cannot be made single pass on tube side; therefore, true counter-current flow is not possible
  • Tube wall at U-bend is thinner than at straight portion of tube
  • Draining tube side is difficult in vertical (head-up) position
Selection Tips
  • For oil heaters, wherever possible put steam through the tube side to obtain the most economical size

Removable Partition Plates With Compression Endplates and Frame

Advantages
  • Ease of disassembly for cleaning or replacement parts
Limitations
  • Not Suitable for pressures over 300 psig
  • Not Suitable for change of state or gaseous applications
Selection Tips
  • For applications involving temperature crossing
  • Economical when exotic metals are required

Brazed Plate

Advantages
  • Very compact and rugged
  • Lightweight
  • Many design options, including multiple passes, different plate styles, nozzle sizes and orientation
  • High heat transfer performance
No gaskets
  • Limitations
  • Can only be cleaned chemically
Selection Tips
  • For applications involving temperature crossing or close temperature approach
  • Ideal for refrigerant-to-liquid or refrigerant-to-gas applications
  • Very economical when compared to all-stainless tubular construction

Heavy Duty Removable Core Type

Advantages
  • Tubes free to expand individually
  • Heating elements totally removable for maintenance or replacement without disconnecting outer casing from ductwork
  • Embedded or extruded fins available for higher design temperatures (750° F max.)
Limitations
  • Individual tubes cannot be cleaned or plugged

303-232-4100