eprintid: 328
rev_number: 15
eprint_status: archive
userid: 7
dir: disk0/00/00/03/28
datestamp: 2011-06-06 15:35:23
lastmod: 2015-05-29 19:57:04
status_changed: 2011-06-06 15:35:23
type: report
metadata_visibility: show
item_issues_count: 0
creators_name: Byatt-Smith, J.
creators_name: Day, R.
creators_name: Harlen, O.
creators_name: Howison, S.D.
creators_name: Lister, J.
creators_name: Smith, S.L.
creators_name: Stone, R.
title: Minimum Particle Size for Cyclone Dust Separator
ispublished: pub
subjects: environment
subjects: transport
subjects: materials
studygroups: esgi29
companyname: Perkins Technology
full_text_status: public
abstract: Perkins technology wish to separate small soot particles from exhaust gases, and the question posed to the study group was to determine the feasibility of using a cyclone separator to remove these particles. Soot is mostly composed of polycyclicaromatic compounds and results from the incomplete combustion of the diesel fuel in the engine. The average size of the particles formed in the engine is in the range 3 to 10 nm in diameter, but this is known to increase within the exhaust system.

In the first part of this report we determine the minimum particle size that can be removed by centrifugal separation. 
The second part discusses the mechanisms for particle growth within the exhaust system in order to estimate the particle growth rate.

In section two we estimate the minimum particle diameter that can be removed by a cyclone separator is around one micron. This estimate is consistent with current applications of hydrocyclones. The particle size  measurements by Perkins Technology together with our estimates from section three, suggest that the soot particles are an order of magnitude smaller than this. Although it may be possible to remove some particles less than one micron in diameter with a well designed high-speed cyclone, we do not think it will be possible to remove a substantial proportion of 100 nm or smaller particles.

The growth rate of the particles increases if the particles volume fraction or the polydispersity is increased. Therefore aggregation could be enhanced by the addition of larger particles (d > 1 µm) or water droplets (provided the water does not all vapourise) to the exhaust gas.
date: 1996
citation:   Byatt-Smith, J. and Day, R. and Harlen, O. and Howison, S.D. and Lister, J. and Smith, S.L. and Stone, R.  (1996) Minimum Particle Size for Cyclone Dust Separator.  [Study Group Report]     
document_url: http://miis.maths.ox.ac.uk/miis/328/1/minimum-particle-size-for-cyclone-dust-separator.pdf