Mass Transfer Units in Single and Multiple Stage Packed Bed, Cross-Flow Devices

Abstract

The flow rate and power requirement ratios decrease with increasing dimensionless frequency and ultimately approach values of unity. At low dimensionless frequencies, the flow and power ratios reach maximum asymptotic values.6. If the rheological behavior of a polymer solution or polymer melt can be described by an Ellis or power law model, the dimensionless graphs can be used to estimate flow rates and power requirements for a pulsating flow process.

Design of aeration towers to strip volatile contaminants from drinking water

“…Data for some solutes in water are Increased liquid and gas flow rates result ir increased gas pressure drop through i packed tower (L = liquid rate, Ib/sq fhhr). For 50-mm Berl saddles and a liquid flux rate of L' = 5 kg/m' * s (3700 lb/sq ft/hr) the value of kLa at 20°C for stripping of CHCl, is about 0.7 min-', computed using Eq (17). This compares with kLa values for diffused air systems of from 0.06-0.2 min-'.…”

“…l Determine the required column dia .meters for the specified water loading r ate. l Compute the liquid-phase mass t ransfer coefficient KLa and the height of : transfer unit for each value of L using i7 5q (17) or literature correlations.…”

“…Stripping tower efficiency and tower hydraulic characteristics are strongly dependent on the water and air design temperatures. As the water temperature drops, both Henry's constants ( Table 2) and mass transfer coefficients [Eq (17)] decrease, making removal by stripping more difficult. In the design example, both the tower diameter and packing depth would increase as the design water temperature decreased.…”

A review on an electrochemically assisted-scrubbing process for environmental harmful pollutant's destruction

“…In a cross-flow absorber, the gas stream flows horizontally through the packed bed, which is irrigated by the scrubbing liquid flowing down through the packing material. Thibodeaux et al evaluated this cross flow packed column scrubber (static mixtures) for NH 3 and CO 2 absorption, as model compounds, to determine the mass transfer properties [79][80][81][82]. The design procedure for cross-flow absorbers is more complex because concentration gradients exist in two directions: from the top to bottom and from the front to rear.…”

A Novel Cross-Flow Cascade Packed Column Design and Simulation

“…A conventional cross-flow cascade column is shown in Figure . The characteristics of cross-flow operations have been discussed by many investigators. − The key factor that hinders the improvement of pressure drop and separation effectiveness is the flow conditions of liquid and vapor in the column, so improving the flow modes of liquid and vapor in the column is the key to the solution to the problem. This paper describes a novel cross-flow cascade packed column design.…”