Boiling in vertical tubes

Chen s method was developed from experimental data on forced convective boiling in vertical tubes. It can be applied, with caution, to forced convective boiling in horizontal tubes, and annular conduits (concentric pipes). Butterworth (1977) suggests that, in the absence of more reliable methods, it may be used to estimate the heat-transfer coefficient for forced convective boiling in cross-flow over tube bundles using a suitable cross-flow correlation to predict the forced-convection coefficient. Shah s method was based on data for flow in horizontal and vertical tubes and annuli. 

Bennett, D. L., and J. C. Chen, 1980, Forced Convective Boiling in Vertical Tubes for Saturated Pure Components, and Binary Mixtures, AIChEJ. 26 454. (4)... 

Kozlov, B. K., 1954, Forms of Flow of Gas-Liquid Mixtures and Their Stability Limits in Vertical Tubes, Zh Tekh. Fiz. 24( 12) 2285—2288. Transl. RJ-418, Assn. Tech. Service, East Orange, NJ. (3) Kramer, A. M., 1958, Boiling Water Reactors, Addison-Wesley Pub. Co., New York, (4)... 

Owens, W. L., Jr., and V. E. Schrock, 1960, Local Pressure Gradients for Subcooled Boiling of Water in Vertical Tubes, ASME Paper 60-WA-249, ASME, New York. (4)... 

Evaluation of the boiling heat transfer coefficient in vertical tubes, as in thermosyphon reboilers, is based on a group of equations, (42)-(48), of Table 8.10. A suitable procedure is listed following these equations in that table. 

The synthesis loop consists of a recycle compressor, feed/effluent exchanger, methanol reactor, final cooler and crude methanol separator. Uhde s methanol reactor is an isothermal tubular reactor with a copper catalyst contained in vertical tubes and boiling water on the shell side. The heat of methanol reaction is removed by partial evaporation of the boiler feedwater, thus generating 1-1.4 metric tons of MP steam per metric ton of methanol. Advantages of this reactor type are low byproduct formation due to almost isothermal reaction conditions, high level heat of reaction recovery, and easy temperature control by... 

Forced-Recirculation Reboilers In forced-recirculation reboilers, a pump is used to ensure circulation of the liquid past the heattransfer surface. Force-recirculation reboilers may be designed so that boiling occurs inside vertical tubes, inside horizontal tubes, or on the shell side. For forced boiling inside vertical tubes. Fair s method (loc. cit.) may be employed, making only the minor modification that the recirculation rate is fixed and does not need to be balanced against the pressure available in the downcomer. Excess pressure required to circulate the two-phase fluid through the tubes and back into the column is supphed by the pump, which must develop a positive pressure increase in the liquid. 

Steiner, D., andTaborek, J., Elow Boiling Heat Transfer in Vertical Tubes Correlated by an Asymptotic Model, Heat Transfer Engineering 13 (2), 43 (1992). 

In process plants liquids are boiled in kettle-type boilers containing a pool of boiling liquid or in vertical-tube calandrias though which the liquid and vapor flow upward through the tubes. Sometimes, as described in Chap. 16, the liquid is heated under pressure to a temperature well above its normal boiling point and then allowed to flash (partially vaporize) by reducing the pressure at a point external to the heat-transfer equipment. 

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