Shell and tube heat exchanger
The shell and tube heat exchanger ( RWÜ ) is a thermal apparatus for transferring heat energy from one body to second. Sometimes a tube bundle heat exchanger is referred to as " recuperator ", because it transfers the heat, in contrast to the regenerators without intermediate storage. Widely used is still the name of shell and tube heat exchanger. This term is misleading, however, since heat is only transferred from the hot medium to the Cold and will not be replaced.
For tubular heat exchangers is indirect heat exchanger, since the heat is transferred through walls and the two media are separated. Mass transfer is therefore not possible.
Technically, the shell and tube heat exchanger is realized by a hollow cylinder made of sheet steel, inside which there are hundreds to thousands of tubes with a small nominal size. Through the plate cylinder flows through the first medium, the second through the pipes. In this operation, the hotter medium is cooled, while the colder medium is heated.
Depending on the mode of operation and flow direction of media differentiates:
- Gegenstromrekuperatoren
- Kreuzstromrekuperatoren
- Gleichstromrekuperatoren
The transfer of heat is best guaranteed when Gegenstromrekuperator, when Gleichstromrekuperator the heat is transferred, however, not so good for the Gleichstromrekuperator is better suited for the rapid cooling / heating. The Kreuzstromrekuperator lies with his performance between the other two types.
Examples of shell and tube heat exchangers:
- Capacitor as Kreuzstromrekuperator
- , Mostly operated oil cooler to large machines as Gegenstromrekuperator
- Exhaust gas heat exchangers in industrial processes
Recuperators are used to recover waste heat from stoves. The hot exhaust gases are routed through channels or pipes, on the heated walls to warm the drifting into the furnace gases. The wall, which conveys the heat, can be made of heat-resistant steel, cast iron or ceramic. Recuperators are the heat and annealing furnaces downstream, they improve their efficiency and increase the oven temperature.
Width using find and tube heat exchangers in the chemical industry and in the food industry. They are used in a variety of forms for heating, evaporation, cooling and condensing of media.