A Fixed Tube Sheet heat exchanger is the most common type of heat exchanger in all Industries. Mostly used in higher-pressure and Higher Temperature applications.
Fixed tube Sheet heat exchangers are the one that are very much used in process chemical industries and refinery services, as there is absolutely no chance for intermixing of fluids. This type of heat exchanger is employed where even slightest intermixing of fluids can not be tolerated. A ﬁxed-tubesheet heat exchanger has straight tubes that are secured at bothends to tubesheets welded to the shell. The construction may have removable channelcovers , bonnet-type channel covers , or integral tubesheets. The principal advantage of the ﬁxedtubesheet construction is its low cost because of its simple construction. In fact,the ﬁxed tubesheet is the least expensive construction type, as long as no expansion jointis required.
- The tube sheets at both ends of the fixed tube-sheet heat exchanger are connected and fixed with the shell by means of the welding method.
- Fixed tube-sheet type heat exchanger features simple and compact structure, and low manufacturing cost for the same diameter of shell, the biggest number of caladria is available in tubular heat exchangers is widely applied in engineering.
- In the event of a large differential temperature between the tubes and the shell, thetubesheets will be unable to absorb the differential stress, thereby making it necessary toincorporate an expansion joint.
- This takes away the advantage of low cost to a significant extent.
- The Fixed tube-sheet heat exchanger are that shell pass cannot be cleaned with the mechanical method and the maintenance is difficult.
- The Fixed tube -sheet heat exchanger is applicable to all services where the temperature difference between the shell and tube is small, the temperature difference is slightly great but the pressure of shell pass is not high with media in the shell pass not easy to scale.
- The shell pass can be cleaned with chemical method after the scaling is formed.
- The tubes can be cleaned mechanically after removal of thechannel cover or bonnet, and that leakage of the shellside ﬂuid is minimized since thereare no ﬂanged joints.
- A disadvantage of this design is that since the bundle is ﬁxed to the shell and cannot beremoved, the outsides of the tubes cannot be cleaned mechanically.
- Its applicationis limited to clean services on the shellside.
- Satisfactory chemical clean-ing program can be employed, ﬁxed-tubesheet construction may be selected for foulingservices on the shellside.