A compressor supplies ambient air from below into the absorption column. Water flows down as a thin film at the edge of the absorption column. The air flows upwards centrally in the column. A portion of the air’s oxygen is dissolved in the water film. The air flow exits the column at the top. The water containing the dissolved oxygen leaves the column at the bottom and flows into a tank. A pump supplies the water with the dissolved oxygen to the head of the desorption column.

Absorption is used to remove one or more gaseous components from a gas flow using a solvent. Selective absorption is an important industrial process for the treatment of gas mixtures.

The oxygen concentration and temperature are continuously measured both upstream and downstream of the absorption column. Valves and flow meters make it possible to adjust the air flow rate and solvent flow rate. Transparent materials allow optimal observation of the processes in both columns.

The desorption column is a simple tube in which the water flows downwards. Nitrogen from a compressed gas cylinder enters at the base of the column. The nitrogen rises to the top in the form of dispersed bubbles in the water. For this reason, a portion of the oxygen passes over from the water into the gas phase (stripping). This process leads to the water’s absorbing capacity for oxygen increasing. The partial pressure of the oxygen in water is higher than the partial pressure in the gas phase (nitrogen).

A pump supplies the solvent regenerated in this way into a channel circulating the upper part of the absorption column. From here the water again flows along the inner wall of the absorption column as a thin falling film and absorbs a portion of the air’s oxygen.

Specification:

Falling film column for the absorption of oxygen from the ambient air in a solvent (water)

Counterflow process

Pump for recirculating the solvent to the absorption column

Measurement of oxygen concentration, temperature and flow rate

2 hand-held measuring units for measuring the oxygen concentration upstream and downstream of the absorption column

1 compressor for supplying ambient air into the falling film column

Continuous regeneration of the solvent with nitrogen in a desorption column by stripping pump for desorption column

Technical data:

Absorption column

Height: 890mm

Inner diameter: 32mm

Material: glass

Desorption column

Height: 1650mm

Inner diameter: 24mm

Material: PMMA

2 pumps

Max. flow rate: 58L/min each

Max. head: 3,7m each

1 compressor

Max. positive pressure: 2bar

Max. flow rate: 23L/min

1 tank

Capacity: approx. 50L

Material: plastic

Measuring ranges

Water flow rate: 40…360mL/min air flow rate: 20…360NL/h

Temperature:: 2x 0…50°C oxygen concentration: 2x 0…70mg/L

230V, 50Hz, 1 phase 230V, 60Hz, 1 phase 120V, 60Hz, 1 phase

Dimensions and weight

LxWxH: 1050x700x2140mm

Weight: approx. 135kg.

Falling Film Absorption