Influence of the Distributor Plate and Operating Conditions on the Fluidization Quality of a Gas Fluidized Bed

Abstract

Experiments were carried out to examine the influence of both the type and the pressure drop of distributor plates on the fluidization quality of an atmospheric fluidized bed. Three different distributor types were used, perforated Perspex, metallic mesh, and porous ceramic, with pressure drops ranging from 0.05 to 350 kPa and superficial air velocities ranging from 0.1 to 2.3 m=s. Three sizes of silica Ballotini beads, 355-425, 600-710, and 850-1000 mm, were used as bed material. The static bed height was set to 300 mm and was divided into six horizontal 50 mm high slices. For each slice, pressure drop values were recorded for U 0 =U mf ratios from 20 to 1. In order to produce a reference for the pressure drop evolution, a modification of the two-phase theory was introduced, taking into consideration the increase in the average global porosity as well as the change in the ratio of flow through the bubbles versus the flow through the dense phase. This allowed assessment of the influence of the different operating conditions and setups on the quality of fluidization, Q Ã .

Image velocimetry and statistical analysis of a mesh-coupled axial blade distributor for mass transfer in a swirling bed

“…The most important part of the fluidized beds is the air distribution system which is supposed to distribute the air evenly throughout the bed and to support the material in the settled bed (Paiva et al, 2009). The efficiency of operation depends upon design of the air distributor.…”

“…The efficiency of operation depends upon design of the air distributor. Various air distributor designs were reported in the past (Sutar and Sahoo, 2011;Paiva et al, 2009;Brink et al, 2011;Faizal et al, 2012). The most popular air distributor geometry for SFBs is the annular blade distributor.…”

Distribution of Solids in a Fluidized Bed Operated without a Gas Distributor

“…For a stable operation, Zuiderweg (1967) proposed that a ratio for a distributor pressure drop to the overall pressure drop can be selected from the range 0.2 -0.4. Different literatures (Sobrino et al, 2009;Paiva et al, 2009) have investigated the effect of a distributor on a fluidized bed behaviour. Although, some studies employ larger particles at the bottom of a bed as a gas distributor, no available literature has described the performance of a bed without a gas distributor.…”

Flow Characteristics of Gas Permeation through a PVF Porous Tube

“…Using this method, Sha [4] simulated the flow in a vapor generator and the core of a nuclear reactor, and Prithivira [5] simulated the flow in a three-dimensional heat exchanger. Paiva et al [6] analyzed the influence of porous plates on a gas fluidized bed. A diffused pneumatic silencer was simulated [7], and the internal and external flow fields of the silencer were obtained.…”