Heat exchangers tube data

APPENDIX 6 CONDENSER AND HEAT EXCHANGER TUBE DATA 1089... 

Appendix 6 Condenser and Heat-Exchanger Tube Data 1088... 

Equipment for Heat Exchange 419 Table 13.4 Heat Exchanger Tube Data... 

Walker, R. A. and T. A. Bott, An Approach to the Prediction of Fouling in Heat Exchanger Tubes from Existing Data, Trans. Instn. Chem. Eng., London, V. 51 (1977) pp. 165-167. 

Finned tube heat exchangers, practical data 54 ... 

Figure 15-12 presents average cost data for heat exchanger tubing constructed of steel. The average purchased cost of complete heat exchangers with... 

Welded and seamless heat-exchanger tubing. Basis of the cost data Includes quantity, 40,000 lb or ft lengths, cut lengths within range of 10-24 ft specifications, seamless, ASTM-A-129 and welded ASTM-A-214 wall thickness, minimum wall. Material of construction is low-carbon (less than 0.18 percent) steel. 

Bott, T.R. and Walker, R.A., 1973, An approach to the prediction of fouling in heat exchanger tubes fi"om existing data. Trans. Inst. Chem. Engrs. 51, No. 2, 165. 

Mott and Bott [1991] compared the accumulation of biofilm on simulated heat exchanger tubes. The equilibiium or plateau value of biofilm deposit, has the highest for 316 stmnless steel tubes with lower amounts on electropolished stainless steel, glass and fluorinated ethylene propylene. Table 15.7 summarises their data. The tests were carried out using Pseudomonas fluorescens under identical conditions. The velocity of flow through the tubes was 1 m/s. 

Although the two examples of laboratory equipment shown in Figs. 17.1 and 17.3 are for heat exchanger tubes other test sections may be used depending on the data desired. Square or rectangular flow sections may be employed where it is desired to remove a flat plate or coupon, for visual or other examination. Fig. 17.5 is an example [Patel 199 ]. Suitable studs may be incorporated into the wall of a tubular test section for the same purpose, but because of the curvature, the area of stud surface exposed to the flow is of necessity quite small. Fig. 17.6 is an example of a so-called Robbins device used in biofilm assessment. 

Tube shape - the prevailing or typical form of the SG heat exchanging tubes. The majority of steam generators have either straight tubes or U-tubes. Data providers should choose the appropriate option from the multiple-choice menu U-tube, straight, mushroom, finned, helical, N/A. 

Tube material - the material of the heat exchanging tubes. Usually, it is a stainless steel. Data providers should enter either the common name of the material (e g. stainless steel) including the alloying elements (e g. Cr-Ni-Ti) or a commonly-used commercial name (e g. Inconel 600, 690, Incaloy 800). 

Temperature profiles inside TVA ammonia synthesis reactor. 1, Gas in heat exchanger tubes 2, gas in catalyst bed full curve 2, simulated dashed curve 2, plant data. From Baddour et al. [1965]. 

To prevent severe erosion by jet impingement of internals such as heat exchanger tubes, one must know how far a vertical jet issuing from a distributor such as a perforated plate will penetrate into a fluidzed bed. This knowledge is also required to prevent piercing by jets of the surface of shallow beds. Blake et al. [58] reviewed the correlations and data available in the literature for the penetration depth of upward jets into fluidized beds. They proposed the following correlation ... 

Notable publications include early US Patents, many of which are related to plastic heat exchangers for applications as solar heaters, made using sheets and films. At least one suggests a tube type assembly but made by the metal injection lost core technique [3], Several web sites offer variations on plastic heat exchangers, some for buildings and one for military vehicles [4], One technical automotive paper containing plastic heat exchanger test data has been published in collaboration with a well known resin supplier [5],... 

Example 7.4 For the process in Pig. 6.2, the stream and utility data are given in Taible 7.1. Pure countercurrent (1-1) shell and tube heat exchangers are to be used. 

Effect of Uncertainties in Thermal Design Parameters. The parameters that are used ia the basic siting calculations of a heat exchanger iaclude heat-transfer coefficients tube dimensions, eg, tube diameter and wall thickness and physical properties, eg, thermal conductivity, density, viscosity, and specific heat. Nominal or mean values of these parameters are used ia the basic siting calculations. In reaUty, there are uncertainties ia these nominal values. For example, heat-transfer correlations from which one computes convective heat-transfer coefficients have data spreads around the mean values. Because heat-transfer tubes caimot be produced ia precise dimensions, tube wall thickness varies over a range of the mean value. In addition, the thermal conductivity of tube wall material cannot be measured exactiy, a dding to the uncertainty ia the design and performance calculations. 

The values of CJs are experimentally determined for all uncertain parameters. The larger the value of O, the larger the data spread, and the greater the level of uncertainty. This effect of data spread must be incorporated into the design of a heat exchanger. For example, consider the convective heat-transfer coefficient, where the probabiUty of the tme value of h falling below the mean value h is of concern. Or consider the effect of tube wall thickness, /, where a value of /greater than the mean value /is of concern. 

For extended surfaces, which include fins mounted perpendicularly to the tubes or spiral-wound fins, pin fins, plate fins, and so on, friction data for the specific surface involved should be used. For details, see Kays and London (Compact Heat Exchangers, 2d ed., McGraw-HiU, New York, 1964). If specific data are unavailable, the correlation by Gunter and Shaw (Trans. ASME, 67, 643-660 [1945]) may be used as an approximation. 

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