Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN CD: 1-56700-226-9

ISBN Online: 1-56700-225-0

International Heat Transfer Conference 13
August, 13-18, 2006, Sydney, Australia

CRITICAL PENETRATION VELOCITY FOR PARTICULATE FOULING LAYERS

Get access (open in a dialog) DOI: 10.1615/IHTC13.p19.10
13 pages

Abstrakt

Particulate fouling is defined as the accumulation of particles on a heat transfer surface forming an insulating powdery layer, which reduces the heat transfer rate, and causing major problems in waste incinerators and biomass gasifiers. The velocity above which an incident particle penetrates into a powdery fouling layer is an important parameter to control particulate fouling using removal by foreign particles. This so-called penetration velocity is studied in detail in the present contribution using 3 different approaches: numerically using the discrete element method, analytically using a 2-body collision model and experimentally. It is found that it is not possible to calculate the velocity at which an incident particle penetrates into a particulate fouling layer by simplifying the interaction as a two-body collision. Penetration of particles into particulate fouling layers can be modeled using the discrete element method. Removal of particles from particulate fouling layers becomes easier as the mass of the incident particle becomes larger than the particle of the fouling layer. Self-cleaning of heat exchangers can be attained by introducing large particles in the flow at constant intervals of time, which have masses larger than the already deposited particles, i.e. the particles in the fouling layers.