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=Baffles (Shell and tube heat exchanger)= A Baffle is an integral part of the Shell and Tube Heat Exchanger design. They are designed to support the tubual bundles and direct the flow of fluids for maximimum efficiency.

Use of Baffles
The main roles of a Baffle are:
 * Hold tubes in position (preventing sagging), both in production and operation. This is also mainly to prevent the effects of vibration, which is increased with velocity and length of exchangers.
 * Direct shell-side fluid flow along tube field. Increasing velocity and effectively the heat transfer co-efficient of the exchanger.

Types of Baffles
Implementation of baffles is decided on the basis of size, cost and importantly their ability to lend support to the tube bundles and direct flow. Often this is linked to available pressure drop and indeed the size and number of passes within the exchanger. Special allowances/changes are also made for finned tubes. The different types of baffles include:
 * Segmental Baffles (of which single segment is the most common)
 * Rod or Bar Baffles (giving a uniform shell-side flow)
 * Helical Baffles (similar h to segmental with less pressure drop for same size exchanger)
 * Longitudinal Flow Baffles (used in a two pass shell)
 * Impingement Baffles (used for protecting bundle when entrance velocity is high)

Installation of Baffles
As mentioned Baffles deal with the concern of support and fluid direction in heat exchangers. In this way it is vital that they are spaced correctly at installation. The minimum Baffle spacing is the greater of 50mm or 1/5 inner shell diameter. The maximum Baffle spacing cut is dependent on material and size of tubes, the Tubular Exchangers Manufacturers Association sets out guidelines. There are also segments with a "no tubes in window" design that effects the acceptable spacing within the design. An important design consideration is that no recirculation zones or dead spots form - both of which are counterproductive to effective heat transfer.