Local shell-side coefficients in shell and tube exchanges the use of a mass transfer technique

  • Nigel V. Mackley

Student thesis: Doctoral ThesisDoctor of Philosophy

Abstract

A diffusion-controlled electrochemical mass transfer technique has been employed in making local measurements of shell-side coefficients in
segmentally baffled shell and tube heat exchangers. Corresponding heat
transfer data are predicted through the Chilton and Colburn heat and mass
transfer analogy.
Mass transfer coefficients were measured for baffle spacing lengths of individual tubes in an internal baffle compartment. Shell-side pressure
measurements were also made.
Baffle compartment average coefficients derived from individual tube
coefficients are shown to be in good agreement with reported experimental
bundle average heat transfer data for a heat exchanger model of similar
geometry. Mass transfer coefficients of individual tubes compare favourably with those obtained previously by another mass transfer technique.
Experimental data are reported for a variety of segmental baffle
configurations over the shell-side Reynolds number range 100 to 42 000.
Baffles with zero clearances were studied at three baffle cuts and two baffle spacings. Baffle geometry is shown to have a large effect on the distribution of tube coefficients within the baffle compartment.
Fluid "jetting" is identified with some baffle configurations. No simple
characteristic velocity is found to correlate zonal or baffle compartment
average mass transfer data for the effect of both baffle cut and baffle spacing.
Experiments with baffle clearances typical of commercial heat exchangers are also reported. The effect of leakage streams associated with these baffles is identified.
Investigations were extended to double segmental baffles for which no data had previously been published. The similarity in the shell-side characteristics of this baffle arrangement and two parallel single segmental baffle arrangements is demonstrated.
A general relationship between the shell-side mass transfer performance and pressure drop was indicated by the data for all the baffle configurations examined.
Date of AwardNov 1973
LanguageEnglish
SupervisorB. Gay (Supervisor) & J.D. Jenkins (Supervisor)

Keywords

  • Local shell-side coefficients
  • shell and tube exchanges
  • mass transfer technique

Cite this

Local shell-side coefficients in shell and tube exchanges the use of a mass transfer technique
Mackley, N. V. (Author). Nov 1973

Student thesis: Doctoral ThesisDoctor of Philosophy