The information below outlines various design types of heat exchangers along with their advantages, limitations, and selection tips.
Non-Removable Bundle, Fixed Tubesheet
Advantages of Non-Removable Bundle, Fixed Tubesheet
- 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 of Non-Removable Bundle, Fixed Tubesheet
- 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 Non-Removable Bundles
- 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 of Removable Bundle, Packed Floating Tubesheet
- 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 of Removable Bundle, Packed Floating Tubesheet
- 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 of Removable Bundle, Packed Floating Tubesheet
- 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 of a Removable Bundle, Pull-Through Bolted Internal Floating Head Cover
- 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 of a Removable Bundle, Pull-Through Bolted Internal Floating Head Cover
- 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 of Removable Bundles with Internal Clamp Ring-Types
- Allows for differential thermal expansion between the shell and tubes
- Excellent for handling flammable and/or toxic fluids
- Provides multi-tube pass arrangements
Limitations of Removable Bundles with Internal Clamp Ring-Types
- 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 of Removable Bundles with Internal Clamp Ring-Types
- 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 of Removable Bundle, U-Tube
- 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 of Removable Bundle, U-Tube
- 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 of Removable Bundle, U-Tube
- 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 of Removable Partition Plates
- Ease of disassembly for cleaning or replacement parts
Limitations of Removable Partition Plates
- Not Suitable for pressures over 300 psig
- Not Suitable for change of state or gaseous applications
Selection Tips of Removable Partition Plates
- For applications involving temperature crossing
- Economical when exotic metals are required
Brazed Plate
Advantages of Brazed Plate
- 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 of Brazed Plate
- 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 of Heavy-Duty Removable Core Types
- 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 of Heavy-Duty Removable Core Types
- Individual tubes cannot be cleaned or plugged