1 Em1


absolute entrainment

L + e total liquid flow rate sieve plate, instead of the downcomer, which is the preferred path for the liquid. If weeping is significant, then it results in mixing of liquid streams between two neighbouring trays, thus degrading the performance of the column. The need to avoid weeping places a limit on the minimum vapour velocity. Zuiderweg presents the following correlations to predict the minimum operating limit.

Mixed/free bubbling regime

Emulsion flow regime

CFw = 0.45F^gh where e is the entrained liquid in moles per hour. Zuiderweg presents the following empirical equation to predict the liquid entrainment in the spray regime:

Here Hs is the tray spacing in metres, hb is the bed height as defined in eqn [8], ugh is the vapour velocity in the hole in metres per second and ul is the horizontal liquid velocity.

Weeping Point Determination

When the vapour velocity is too small, the liquid on a tray deck can flow down through the holes on the where CFw = us^pG/(pL — pG) is the capacity factor at the weep point in metres per second, and F is the fractional hole area per unit bubbling area. Correlations to estimate the type of flow regime are given by Zuiderweg. Note that weeping will seldom occur in the spray regime as vapour velocities are sufficiently large under design conditions. The effect of weeping on the tray efficiency calculation has been studied by Kageyama (1969).

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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