Gaseous Diffusion Coefficient Apparatus
- A small quantity of the volatile liquid
to be investigated is placed in a capillary tube, which is positioned
in a heated metal block. The block is heated by an electric cartridge
- heater and kept at a constant temperature using an electronic control loop.
- A stream of air is passed across the
top of the capillary tube, with a stationary layer of air above the
liquid surface, creating a partial pressure difference between the
liquid surface and the flowing air stream. As vapour diffuses from the
liquid into the air stream, the amount of liquid in the tube reduces and
the phase boundary between the liquid and the air drops. Measurement of
how this phase boundary changes with time enables the molar mass
transfer rate to be determined.
- A slot in the heater block enables the
phase boundary to be observed using a high definition microscope. This
micro-scope produces high definition images onto a standard windows
computer (not supplied).
- The software provided with this
microscope includes highly accurate measurement and an automated time
lapse facility (either as video or multiple still images).
Instruction Capabilities:
- Direct measurement of mass transfer rates in the absence of convective effects
- Use of gas laws to calculate concentration differences in terms of partial pressures
- Use of Fick’s Law to measure diffusion coefficients in the presence of a stationary gas
- Measurement of the effect of temperature on diffusion coefficients
- Gaining familiarity with the use of
laboratory instruments to achieve accurate measurements of data required
for industrial process design
- Investigation into diffusion coefficients of alternative fluids
Gaseous Diffusion Coefficient Apparatus ALTEC Laboratory Equipments and ALTEC Laboratory Instruments Tenders.