What is a double tubesheet heat exchanger?
Double-tube-sheet heat exchangers are used for applications wherein mixing of tube-side and shell-side fluid must be avoided. Such a scenario demands the non-mixing of shell-side and tube-side fluids. Another example is a power plant condenser. In this application, water is used as a cooling medium.
What is double heat exchanger?
DOUBLE PIPE HEAT EXCHANGER. A double pipe exchanger consists of one or more pipes or tubes inside a pipe shell. Basically two straight pipe lengths are connected at one end to form a U or “hair-pin.” Longitudinal fins may be used on the outside of the inner tube.
What is 2/4 pass 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 a double tube sheet?
Double tubesheets are used for applications where the mixing of the tube-side fluid and the shell-side fluid must be avoided. The gap between the two tubesheets is open to the atmosphere so any leakage of either fluid should be visually and quickly detected.
What is floating head in heat exchanger?
Floating head heat exchanger is one of the most used heat exchanger. As shown in the name of it, in this design, one end of the tubesheet is fixed to the shell, while the other one can “float” freely inside the shell.
What are double pipe heat exchangers used for?
Double-pipe heat exchangers are used in many industries because of their low design and maintenance costs, flexibility, and low installation costs [25]. They are mainly used for sensible heating or cooling of process fluids in applications of small heat transfer areas of up to 50 m2 [38].
What is the difference between double pipe and shell and tube heat exchanger?
Double pipe heat exchanger consists of two concentric pipes of different diameters. One pipe is for hot fluid and another is for cold fluid. Shell and tube heat exchanger consists of a shell in which large number of parallel tubes are present. One fluid hot or cold flow in shell and other hot or cold flow in the tubes.
What is TEMA heat exchanger?
The Tubular Exchanger Manufacturers Association (also known as TEMA) is an association of fabricators of shell and tube type heat exchangers. TEMA has established and maintains a set of construction standards for heat exchangers, known as the TEMA Standard.
What is tube sheet in heat exchanger?
tube-sheet. A tube sheet is usually made from a round flat piece of plate,sheet with holes drilled to accept the tubes or pipes in a accurate location and pattern relative to one another. The tube sheets are used to support and isolate tubes in heat exchangers and boilers or to support filter elements.
How does a double pipe heat exchanger work?
The double pipe heat exchanger works via conduction, where the heat from one flow is transferred through the inner pipe wall, which is made of a conductive material such as steel or aluminum. The double pipe heat exchanger is often used in counterflow, where its fluids move in opposite directions (as shown above).
What are double tubesheet heat exchangers used for?
Double tube and double tubesheet heat exchangers are essential in applications where fluids cannot mix.
When do you expand the tube in a heat exchanger?
In general, tube expansion within the tube-sheet shall always be done after welding of tube-to-tube-sheet joints. This is mainly due to the following reasons: ■ Tube expansion (rolling) before welding may leave lubricant from the tube expander in the tube holes.
What are the different types of double tube sheets?
Typically, the Tubular Exchanger Manufacturers Association (TEMA) covers three types of double-tube-sheet constructions: integral, connected, and separate. In all three types of constructions, care should be taken while designing the tube-to-tube-sheet joint.
When do you need a double pipe exchanger?
Double-pipe exchangers are useful when not more than 100 to 150 ft 2 of heat exchange surface area are required. Beyond this range, it becomes more economical to bundle many tubes in a single shell and avoid the weight of metal required by adding larger pipes or additional passes in a series or parallel arrangement.