Small scale · Work package b and c
Small-scale bubble columns
Six transparent acrylic columns, they differ in the section, in the injector carried on the bottom plate — a needle, rows of needles, and perforated plate — and in the optical access up the height, which is what decides the experiment each one can do. The working fluids range from water to the aqueous ionic-liquid mixtures the project has selected.
Single-bubble column
A rectangular column releases single bubbles, tracked with a high-speed camera to study how they rise, change shape, and wobble in water and ionic liquid solutions, revealing the basic physics behind bubble behaviour in liquids.
Bubble-swarm column
A rectangular column with perforated plates of different hole sizes generates a controlled bubble swarm, tracked through image analysis and gas holdup measurements to reveal flow-regime behaviour feeding into a broader theory of bubble columns.
Circular bubble-swarm column
A transparent cylindrical column about 2 m tall, operated with three different spargers, where gas holdup is measured over four axial sections from differential pressure and complemented by local optical-probe measurements, to follow how the gas fraction evolves along the column.
Coalescence cell
A short rectangular cell is used to study bubble coalescence, where two opposed capillaries nucleate contacting bubbles. High-speed imaging is performed, and coalescence percentage, approach velocity, and coalescence time are quantified through image analysis.
CFD-grade column
A rectangular column with a controlled injection sparger where each hole can be operated independently, giving measurements clean and repeatable enough to serve as a validation case for the project’s numerical work.
Mass-transfer column
A 5 cm cylindrical column inside a square outer container, where two synchronized high-speed cameras reconstruct single bubbles in three dimensions and follow their volume as CO₂ is absorbed, giving a direct measurement of the liquid-side mass-transfer coefficient.
