Q. What do you mean by Shell and Tube Exchangers?

Shell and tube exchanger piping shall be arranged to provide clearance overhead at both bonnet and channel ends. Piping shall be designed with breakout spools at both bonnet and channel ends to enable removal by overhead lifting equipment. Sufficient space should be provided for the removal of tube bundles from shell and tube heat exchangers for maintenance, inspection or replacement.

Horizontal shell and tube exchangers can be stacked two or three high. If larger exchangers need to be stacked more than two high a structure should be considered with each shell separately supported. The following are rules of thumb for stacking:

• 1.2 m in diameter Stacked three high

• 1.2 to 1.8 m in diameter Stacked two high

• Over 1.8 m in diameter Shall not be stacked

Fixed tube shell exchangers require a clear space for in-situ roding out, or tube replacement. Where removal of tube bundles is specified, space should be provided for a crane or proprietary tube pulling equipment. Check the type of bundle pulling method used by the plant. The bundle removal area should not extend over main plant roads, although plot space can be saved if this is allowed by the Client. Shell and tube exchangers in structures need good access to both channel and rear end and may require lifting beams and lay down areas for channel head removal. This requirement must be checked for, early in the design.