Tube counts

Impingement baffles are generally made of rectangular plate, although circular plates are more desirable. Rods and other devices are sometimes used to protect the tubes from impingement. In order to maintain a maximum tube count the impingement plate is often placed in a conical nozzle opening or in a dome cap above the shell. 

Table 3-4 (Continued) Heat Exchanger Tube Count...

Errors in tube count can cause recalculation in expected exchanger performances. ... 

Method of Figuring Tube Counts—Use with Table 10-9... 

Heat Exchanger Tubesheet Layout Tube Count Table... 

To more easily determine the effective tube lengths for U-tubes, the correction chart shown in Figure 10-27B is convenient. The chart is based on many actual U-tube bundle layouts. Values read from the chart are not more than 1 % lower than those obtained by calculations, except where the curve is extrapolated to lower tube counts. Such extrapolations result in errors of 3%, 4%, and higher, giving larger values than those calculated. This does not apply to higher tube count extrapolations. The chart is limited to -in. and... 

Low Tube Counts [Pg.52]

Use two passes in tubes tubes on 1-in. triangular pitch. From the tube count in Table 10-9, a 29-in. I.D. shell will hold 646 tubes, including an allowance for tie rods. The number of tubes per pass = 646/2 = 323. 

Tube count tables which give an estimate of the number of tubes that can be accommodated in standard shell sizes, for commonly used tube sizes, pitches and number of passes, can be found in several books Kern (1950), Ludwig (2001), Perry et al. (1997), and Saunders (1988). 

Shell size could be read from standard tube count tables. 

It should be noted that Equations C.32 and C.33 will tend to overestimate the number of tubes that can be contained in a given shell diameter. The larger the diameter shell, the smaller will be the error in the tube count. Substituting Equation C.33 into Equation C.31 gives ... 

TABLE 8.13. Tube Counts of Shell-attd-Tube Heat Exchengers1 ... 

Triangular layout of tubes is the most encountered. The tube pitch is 1.25 times the outside diameter. Exact tube counting can be obtained by means of specialized design programs. For preliminary calculations the number of tubes can be found by means of relations based on the factor C = (D/d) — 36, where D and d are the bundle and outside tube diameters, respectively. The total number of tubes Nt can be calculated by means of the following relations [1] ... 

Shell O.D. Shell thickness Tube count Surface area for 6.1m (20 ft.) nominal length ... 

As soon as the tube count per compound drops below a defined threshold (e.g. 2 tubes) for a minimum of 384 compounds in the Smart Compound Depository, 384 of these compounds are ordered from the Liquid Master Store in order to prepare new aliquots for replenishment of samples. 

Tube count table, heat exchanges, 203 Tubular heat exchangers sketches, 174, 175... 

TEMA classification, 200 tube count table, 203 Turbine pumps, 134, 139, 140, 142, 143 Turner equation, leaching, 466 Turbogrid trays, 426 Two-phase fluid flow. 111, 113-117 correlations, 115 granular beds, 118 homogeneous model, 113 Lockhart-Martinelli method, 115, 116... 

Carefully decant supernatants into clean 12 x 75 mm tubes. Count the supernatant (super.) and precipitate (ppt) for each of the three tests. 

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