Sepa Finals

Absorption Column

A column where gas is absorbed while a gas mixture bubbles through the liquid, which passes down from plate to plate.

Absorption Factor

A parameter in the Kremser equation for calculation of absorption columns and towers.

Channeling

The condition in which packing surface is not wetted by the flowing liquid due to low liquid rates.

Downcomer

A tube or duct leading liquid from one plate in column to the next plate.

Downflow flooding

In plate columns, excessive build up of liquid on the plates caused by insufficient drainage through the downcomers.

Entrainment flooding

Excessive carry-over of suspended droplets following the vapour or gas upwards through the column.

Flooding velocity

The upper limit to the rate of gas flow.

Lean Gas

Outgoing gas mixture in air or gas absorption column/tower

Rich Gas

Gas mixture entering the gas absorption column/tower

Strong Liquor

The outlet liquid, which is enriched in solute

Weak Liquor

The inlet liquid, which may be the solvent or a dilute solution of solute in the solvent

Loading point

The point in a logarithmic pressure drop – gas velocity diagram for packed columns where the pressure drop start to increase more rapidly with increasing gas or vapor velocity caused by rapid increase in liquid hold-up.

Packed column

A column for distillation, absorption, or extraction, consisting of a cylindrical shell to ensure intimate contact between the rising fluid.

Packing

Small objects used to provide a large contact area between rising fluid and descending liquid in packed columns.

Random packing

In packed columns and towers, packing units lying randomly as they happened to fall when dumped down.

Scrubbing

The process in which a liquid is employed to achieve or assist in the removal of dispersed particles from the gas.

Stacked packing

A packing consisting of symmetric materials stacked on top of each other.

Absorbent

Liquid which takes up one or more components from a gaseous mixture.

Stripping

Process of removing gas dissolved in a liquid and where the liberated gas is taken up in a gas or vapor in contact with the liquid

Solute

Subsequently recovered from liquid by distillation

Solvent

The major liquid component in the feed during Liquid-liquid extraction.

Extraction solvent

The immiscible or partially miscible liquid added to the process to create a second liquid phase.

Loading capacity

It refers to the maximum concentration of solute the extract phase can hold.

10

Partition ratios on this order is desired for an economical process.

High solvent to feed ratio

Partition ratios less than 𝐾𝑖 = 1.0 may be accommodated by using a ___?

25 dyne/cm

Preferred values for interfacial tension between the feed phase and the extraction solvent phase.

Distribution coefficient

Ratio of concentrations of a compound in a mixture of two immiscible phases at equilibrium. Also called partition ratio.

Leaching

Separation is based on the differences in solubility.