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A novel electrical charging condensing heat exchanger for efficient particle emission reduction in small wood boilers

Research output: Contribution to journalArticleScientificpeer-review


Original languageEnglish
Pages (from-to)521-529
Number of pages9
JournalRenewable Energy
Publication statusPublished - Jan 2020
Publication typeA1 Journal article-refereed


Small-scale biomass combustion is an important source of fine particles in ambient air, causing adverse health and environmental effects. Thus, there is a clear need to develop efficient and feasible flue gas cleaning technologies for small-scale combustion appliances. In this study a novel electrical charging condensing heat exchanger (eCHX) for combined fine particle removal and efficient heat recovery from flue gases was demonstrated in a small biomass-fired boiler. The method is based on the combination of a shielded corona charger and a condensing heat exchanger, where fine particles are removed by the electrophoretic, thermophoretic and diffusiophoretic forces. The eCHX was found to decrease >80% of fine particle mass (PM1) emissions and >40% of particle number emissions with simultaneous high thermal efficiency in the heat exchanger. The usage of the condensing heat exchanger without electrical charging resulted in 40% decrease in PM1 emissions when compared to the usage of a traditional tube heat exchanger. The advantage of the eCHX system is that it replaces the conventional heat exchanger in boilers, making it a compact and inexpensive solution, when compared to additional flue gas cleaning devices installed after the boiler.


  • Biomass combustion, Electrical charging, Heat exchanger, Particle emission

Publication forum classification

Field of science, Statistics Finland