Heat transfer on tube bundles embedded horizontally in a liquid-fluidized bed

Abstract

Heat transfer on tube bundles embedded horizontally in a liquid‐fluidized bed was investigated experimentally. In the experiment, a total of 5 kinds of tube bundles in an equilateral triangular staggered arrangement, including a single tube, was used. Tested particles were of glass and ceramics, and their diameter range was from 2.1 to 6.0 mm. It was found that the distribution of local heat transfer coefficients around a tube depends not on the kind of particles, but on the tube pitch only, when a good fluidizing condition is maintained. Based on the experimental data, a new method was proposed to predict average heat transfer coefficient, which can be applicable for tube bundles having a tube pitch to diameter ratio of 1.2 to infinity (single tube). © 2005 Wiley Periodicals, Inc. Heat Trans Asian Res, 34(2): 85–98, 2005; Published online in Wiley InterScience (http://www.interscience.wiley.com). DOI 10.1002/htj.20048

Heat transfer on tube bundles embedded vertically in liquid‐fluidized beds

“…1.75 (6) Note that the inner diameter of the fluidizing column D c in Eq. (5) is replaced by the hydraulic equivalent diameter of flow channel D e defined by Eqs.…”

“…Water at ambient conditions in a water tank (1) is pumped by a pump (2), flows via flow meters (3), control valves (4), and a distribution section (5) into the test channel (6). In the distribution section, ceramic beads having a diameter of 5 mm are charged to supply a uniform flow into the test channel.…”

“…For example, the effect of the wall on bed voidage and heat transfer [2,3], or the flow and heat transfer characteristics of mixed particles [4,5] were clarified for the in-tube fluidization type. For horizontally embedded heat transfer tubes, the heat transfer characteristics of tube bundles in a staggered arrangement [6] and aligned arrangement [7] were clarified, and the heat transfer correlation was developed for each arrangement. exponent in Richardson-Zaki correlation P T : tube pitch Pr: Prandtl number of liquid…”