How big is a shell and tube heat exchanger?
Standard shell sizes from 8 inches through 42 inches in diameter; custom designs up to 60 inches in diameter. ADVANTAGES: Bundle can be removed from shell for cleaning or maintenance.
How do you size a heat exchanger?
ΔTm =
- ΔTm =
- = 94.9 °F. 0.10536.
- The preliminary area estimate of the heat exchanger can now be calculated as: A = Q / (U x ΔTm) =
- A = 2, 035, 000 Btu/hr.
- = 178.7 ft² (120 Btu/h.ft².°F).(94.9°F)
- The required mass flow rate of water can be calculated from Q = m.Cp. ΔTm: Rearranging:
- m = Q…… = Cp x ΔTm.
- m = (2,035,000 Btu/hr)
How do you create a shell and tube heat exchanger?
GENERAL DESIGN CONSIDERATIONS More viscous fluid should be located on the shell side. Lower the flow rate stream should be placed on the shell side. Consider finned tubes when the shell side coefficient is less than 30% of the tube side coefficient. Do not use finned tubes when shell-side fouling is high.
What is clearance in shell and tube heat exchanger?
Clearance is the distance between tubes. Triangular or square arrangement of tubes are quite common. Baffles: Baffles are usually spaced between 20% and 100% of the ID of the shell.
What is 2/4 shell and tube heat exchanger?
Most shell-and-tube heat exchangers are either 1, 2, or 4 pass designs on the tube side. This refers to the number of times the fluid in the tubes passes through the fluid in the shell. Two and four pass designs are common because the fluid can enter and exit on the same side.
What is shell diameter?
Typically shell diameters range from 152 mm to 3000 mm (6″ to 120″).
What is heat exchanger area?
The heat exchangers considered are counter-current tube-shell exchangers. The heat exchange area is calculated in terms of the heat duty, mean logarithmic temperature difference, and the heat transfer coefficient.
What is sizing and rating of heat exchanger?
In a rating problem, the geometry and size of the heat exchanger are fully specified. Entering flow rates and fluid temperatures are known. The job is to calculate the thermal effectiveness (heat transferred) and pressure drop of each stream. Normally, pressure drop limits are given for each fluid stream.
What is baffle spacing?
Baffles. Baffles are used to increase the fluid velocity by diverting the flow across the tube bundle to obtain higher transfer co-efficient. The distance between adjacent baffles is called baffle-spacing. The baffle spacing of 0.2 to 1 times of the inside shell diameter is commonly used.
How many tube passes does a 2/4 shell and tube heat exchanger have?
This flow arrangement produces a 2-4 floating head heat exchanger (2 shell-side passes and 4 tube-side passes).
What does 1/4 shell and tube heat exchanger imply?
Most shell-and-tube heat exchangers are either 1, 2, or 4 pass designs on the tube side. This refers to the number of times the fluid in the tubes passes through the fluid in the shell. In a single pass heat exchanger, the fluid goes in one end of each tube and out the other.
How do you find the shell diameter of a heat exchanger?
The equivalent diameter is calculated along (instead of across) the long axes of the shell and therefore is taken as four times the net flow area as layout on the tube sheet (for any pitch layout) divided by the wetted perimeter.
What are the dimensions of a heat exchanger?
The outside diameter of the heat exchanger tubes ranges from 16 mm to 51 mm according to DIN 28180 and from ½ inch (12.7 mm) to 3 inches (76.2 mm) according to ASTM A179 The tubes for the heat exchangers may be supplied also in compliance with other standards starting with 4 mm.
What kind of tubing is used in a heat exchanger?
Seamless tubing is produced in an extrusion process; welded tubing is produced by rolling a strip into a cylinder and welding the seam. Tubes are made from low carbon steel, stainless steel, titanium, Inconel, Copper, etc. Standard tube diameters of 5/8 inch, 3/4 inch, and 1 inch are preferably used to design compact heat exchangers.
How many passes are there in a shell and tube heat exchanger?
The distance between two baffles is baffle spacing. Multiple Passes. Shell-and-tube heat exchangers can have multiple passes, such as 1-1, 1-2, 1-4, 1-6, and 1-8 exchangers, where the first number denotes the number of the shells and the second number denotes the number of passes.
How are pass partitions used in a heat exchanger?
Pass partitions are required in channels of heat exchangers with multiple tube passes. The pass partition plates direct the tube side fluid through multiple passes. Tubes are generally made seamless or welded. Seamless tubing is produced in an extrusion process; welded tubing is produced by rolling a strip into a cylinder and welding the seam.
