CE 405 Falling Film Absorption Didactic Equipment Heat Transfer Experiment Equipment
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. CE 405 can be used to investigate the basic processes on the water-oxygen-nitrogen system.
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.
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. The partial pressure of the oxygen in water is higher than the partial pressure in the gas phase (nitrogen). 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.
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.
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.
Specification
falling film column for the absorption of oxygen from the ambient air in a solvent (water)
counterflow process
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
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
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
UL/CSA optional
Dimensions and weight
LxWxH: 1050x700x2140mm
Weight: approx. 135kg
Required for operation Nitrogen gas cylinder with pressure reducing valve
