Heat exchangers classification

Because the system is meant to be used for a variety of heat exchangers we could not use a simple (ANN) classifier, but we chose for a CBR type system. The case-base stores signal shapes with corresponding classifications or actions to be taken (e.g. signal mixing). Beftxe each inspection the case-base is filled with data from calibration pipes oc a case-base from a previous similar inspection can be used. For each new possible defect signal a search is done in the case base for the most similar case. 

The various components which make up a shell and tube heat exchanger are shown in Figures 9.63 and 9.64 and these are now considered. Many different mechanical arrangements are used and it is convenient to use a basis tor classification. The standard published by the Tubular Exchanger Manufacturer s Association (TEMA 97 ) is outlined here. It should be added that noting that Saunders 98 has presented a detailed discussion of design codes and problems in fabrication. 

Figure 8.11. Tubular Exchanger Manufacturers Association classification and terminology for heat exchangers, (a) TEMA terminology for shells and heads of heat exchangers, (b) Terminology for parts of a TEMA type AES heat exchanger. The three letters A, E, and S come from part (a).

The presence of internals in a bed, such as baffles and heat exchangers, or variation in geometric configurations, such as tapered geometry, can affect the flow behavior. The classification scheme in Fig. 9.3 is, however, generally applicable to these situations. 

Special devices for classification of crystals may be used in some applications. Figure 14 shows a draft-tube-baffle (DTB) crystallizer that is designed to provide preferential removal of both fines and classified product. As shown, feed is introduced to the fines circulation line so that any nuclei formed upon introduction of the feed can be dissolved as the stream flows through the fines-dissolution heat exchanger. The contents of the crystallizer are mixed by the impeller, which forces the slurry to flow in the indicated direction. A quiescent zone is formed between the... 

Tall oil distillation, 36 TEMA classification, heat exchangers, 200... 

Figure 8-2. Tubular Exchanger Manufacturers Association (TEMA) classification and terminology for heat exchangers. TEMA heat exchanger head types. 

Figure 23.14 outlines a classification of fluidized bed dryers. For heat-sensitive materials, e.g., polymer pellets, use of immersed heat exchangers allows use of lower fluidizing air temperature without increasing drying time. Such exchangers can be used, however, only if the solids do not foul their surfaces. 

R. K. Shah, Classification of Heat Exchangers, in Thermal-Hydraulic Fundamentals and Design, S. Kakac, A. E. Bergles, and F. Mayinger eds., pp. 9-46, Hemisphere/McGraw-Hill, New York, 1981. 

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