Zone spreading and optimisation in parallel plate continuous chromatographs

• Published in: Chemical engineering science Vol. 29; no. 7; pp. 1513 - 1518
• Main Authors: Megy, Joseph, Hawkes, S.J.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.1974
• ISSN: 0009-2509; 1873-4405
• DOI: 10.1016/0009-2509(74)87001-6

Equations are derived describing the performance of parallel plate continuous chromatographs. General equations for emergence angle, stream dispersion, pressure drop, and for throughput of a two-component feed are derived assuming linear partition isotherms and operation near enough to equilibrium for Giddings' approximations to apply. The general equations are reduced to equations for three forms of the chromatograph, with and without packing between the plates. Subject to the limitations of the model, maximum throughput of a two-component mixture is obtained when the input stream enters over nearly π radians and when the revolution of the chromatograph is arranged so that the centres of the two exit streams are separated by π radians, even if this involves an exit angle greater than 2π. The difference in the capacity ratios of the two components should be maximal, but the absolute values are of small importance. The equation for optimum flow rate is derived.