Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Comparative slagging/fouling measurement

A small-scale ash deposition test has been developed as a low-cost tool for the screening of potential fuels for co-firing with coal. Deposition of ash can become a serious problem in coal fired boilers when co-firing secondary fuels at a high rate (more than a few percent). Due to nonlinear interactions between fuels, the composition and properties of the ash particles formed cannot be reliably predicted. As a consequence, the temperature range in which the ash particles soften and eventually melt, is not well known. Full-scale experience is scarce and the evaluation of ash deposition in short-term trials is not simple.

A small-scale test can be performed under well known conditions to compare the ash deposition rate for a fuel blend containing a secondary fuel with the behaviour of a known base fuel. In addition, any samples collected can be analysed to evaluate the deposit in terms of attachment, sintering (relevant for strength) or composition. Samples can also be taken off-line for subsequent deposit-induced corrosion testing. Tests can be carried out to simulate typical slagging (uncooled refractory surface) as well as fouling (cooled metal alloy) conditions. In line with this (comparative) deposition test, the method was extended with an on-line measurement of heat flux through the ash deposit. The principles of this measurement formed the basis for the design of a probe with integrated heat flux sensors.

Reported by

Energy research Centre of the Netherlands
3 Westerduinweg 3PO Box 1
1755 ZG Petten
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