Ventilation of Compost Heating System by Permanent Magnets

The effect of a permanent magnet on ventilation of an air duct through compost has been investigated numerically. Some composts yield heat over $60°C$ in the fermentation process. This exothermic reaction produces a considerable amount of heat, which could be a potential heating source. Fermentation reaction requires ventilation, sufficient supply of oxygen, and exhaust of metabolized diamagnetic carbon dioxide gas. Continuous and forced air supply is more efficient rather than the conventional manual turn or stirring as ventilation means. In magneto-aero-dynamics, the magnetizing force acting on a paramagnetic oxygen gas is applied to enhance air flow, heat, and mass transfer. In our research, the enhancement of the air flow through air ducts of various sizes has been numerically investigated by applying a permanent magnet on an air duct. Numerical results show that a permanent magnet enhances the air flow, where we obtained a maximum inlet air velocity $(uin)$ of $6.24×10−2m/s$⁠. The application of a permanent magnet to an air duct is useful for compost heating system, a promising alternative energy system.