# Concentric tube heat exchanger - Required length

## Description

Concentric Tube (or Pipe) Heat Exchangers are used in a variety of industries for purposes such as material processing, food preparation, and air-conditioning. They create a temperature driving force by passing fluid streams of different temperatures parallel to each other, separated by a physical boundary in the form of a pipe. This induces forced convection, transferring heat to/from the product.

The length of heat exchanger required can then be expressed as a function of the rate of heat transfer as on the shown formula

The Logarithmic Mean Temperature Difference (ΔT) can be calculated from this formula

Related formulas## Variables

A | surface area available for heat transfer (m^{2}) |

Q | rate of heat transfer (W) |

U | Overall Heat Transfer coefficient (W/(m^{2}*K)) |

ΔT | Logarithmic Mean Temperature Difference (K) |