Properties of pulsing flow in a trickle bed

Trickle bed hydrodynamics and flow regime transition at elevated temperature for a Newtonian and a non-Newtonian liquid

“…Temperature indeed had a remarkable effect on liquid holdup which was taken into account in the calculation of the Reynolds number and the corresponding interstitial liquid velocity. The Tsochatzidis and Karabelas (1995) correlation predictions were higher in comparison to those by Burghardt et al (2004) correlation. This latter one provided, however, close estimations of the pulse velocity which can be recommended for approximate estimation of this parameter for aqueous systems at high temperature in addition to its capability to capture high pressure pulse velocity data.…”

“…Similarly, according to experiments with different particle sizes, Rao and Drinkenburg (1983) also observed marginal effect of liquid flow rate and proposed a pulse velocity correlation functionalizing interstitial gas velocity and packing geometry. However, at high liquid flow rate, Tsochatzidis and Karabelas (1995) observed significant influence of this parameter on pulse velocity for the air-water system. They suggested an empirical correlation functionalizing interstitial gas velocity and superficial liquid velocity.…”

“…(1) packed bed, (2) conductance probes, (3) conductimetric sensors, (4) preheater for the gas phase, (5) preheater for the liquid phase, (6) pressure transducer, (7) reservoir, (8) gas-liquid separator, (9) lock-in amplifiers, (10) gas flowmeter, (11) liquid flowmeter, (12) tracer injection loop. In order to measure the pulse properties, an electrical conductance technique was implemented using recommendations and design details provided by Tsochatzidis and Karabelas (1995) and Boelhouwer et al (2002). Two conductance probes were mounted in the middle of the reactor, a distance of 0.225 m apart from each another.…”

“…A great deal of experimental studies dealing with the effect of elevated pressures on TBR hydrodynamics concerned the trickle flow regime. Though the advantages of pulsing flow are well documented in the literature (Rao and Drinkenburg, 1985;Tsochatzidis and Karabelas, 1995;Boelhouwer et al, 2002) interest on pulse flow regime characteristics at elevated pressures is very recent (Burghardt et al, 2002(Burghardt et al, , 2004. Since this flow regime takes place in several industrial applications often at high temperature, it is necessary to unveil the temperature effects on basic characteristics, e.g., pulse velocity, that occur in this particular flow regime.…”

CFD of multiphase flow in packed‐bed reactors: II. Results and applications

“…This is the so-called ''periodic Ž flow operation'' or ''induced pulsing operation' ' Haure et al, . 1989;Tsochatzidis and Karabelas, 1995 . The enlarged pulsing flow regime, favored in most commercial units, has been experimentally found under such an operating mode Ž .…”