Oxygen Supply to Exothermic Combustion Reactions in Compost Heating System (CHS) by Permanent Magnets

The oxygen supply enhancement in a porous compost by permanent magnets have been investigated numerically. The computations were conducted for the cases of neodymium magnet. The magnets were aligned vertically with specified interval in the compost. Darcy model was applied to represent the air flow through the compost and the oxygen concentration was solved by SIMPLE based algorithm, coupled with the fermentation process that occurs in the compost. The following five effects on the oxygen supply enhancement in the compost: 1.permeability through the compost, 2.rate constant of the exothermic reaction in the fermentation process, 3.size of the compost, 4.interval of the magnets and 5.location of the magnets were investigated. As a result, the maximum inlet air velocity reaches 6.4 mm/s when the air permeability is 3.82×10⁻⁴ m². The permanent magnets enhance the air flow and oxygen supply.