2134/3129
Gerhard Schaldach
Gerhard
Schaldach
Harald Berndt
Harald
Berndt
Barry Sharp
Barry
Sharp
An application of computational fluid dynamics (CFD) to the characterisation and optimisation of a cyclonic spray chamber for CP-AES
Loughborough University
2008
untagged
Chemical Sciences not elsewhere classified
Geology
2008-01-21 13:01:08
Journal contribution
https://repository.lboro.ac.uk/articles/journal_contribution/An_application_of_computational_fluid_dynamics_CFD_to_the_characterisation_and_optimisation_of_a_cyclonic_spray_chamber_for_CP-AES/9395771
This paper describes the application of computational fluid dynamics (CFD) to the modelling of the
performance of a cyclonic spray chamber with flow spoiler designed to provide good efficiency with rapid
wash-out time. The modelling is carried out under two flow regimes, one corresponding to typical sample
introduction conditions and one to low sample uptake. Velocity distributions, pressure distributions and mass
flows are simulated, the latter employing the measured primary aerosol distributions as inputs to the
computation. The dynamic performance of chambers is also modelled and the signal profiles produced are
shown to correspond to those derived directly from measurement. Six different chambers are studied
corresponding to a chamber with no spoiler, a single spoiler in four different positions, and a chamber with
3 spoilers. The position of the spoiler is shown to be critical in determining the flow field in the chamber and
hence the efficiency and washout time. It is demonstrated that chamber geometry has maximum impact under
low uptake conditions where the limited dispersion primary aerosol can effectively follow the gas flow lines.
Computation indicates that a chamber with optimised spoiler, operating under low uptake conditions, provides
the best combination of efficiency and response time. This was confirmed by experiment in which the
performance of 3 different chambers was compared, with the optimised design providing detection limits 1.5–
19 better than those obtained with the chamber supplied with the ICP-AES instrument. A chamber with
3 spoilers indicates the formation of a low-volume