Evaluation of the effects of forced aeration during phase I mushroom substrate preparation: Part 2. Measurements and model results

This article is the second of a two-part series on evaluating the effects of forced aeration during Phase I mushroom substrate preparation on substrate temperature, oxygen concentration, and heat generation. Part 2 describes testing of four different aeration schemes: 1, 3, 5, and 10 min of aeration per hour at a flow rate of 0.47 m³/s and a pressure of 6200 Pa. To estimate the rate of heat generation during substrate preparation, an energy balance model was developed and applied to an environmentally controlled Phase I system. This model development is presented in part 1 of this series. Results showed that oxygen demand during Phase I was time dependent, with demand being greatest at the onset of processing and immediately after the substrate was mixed. Results also indicated that heat generation and oxygen demand were greatest at temperatures between 45°C and 60°C and that, during these periods of vigorous activity, at least 61.3 m³/tonne/hour of air should be delivered to the substrate in order to maintain aerobic conditions. At temperatures above 80°C, heat generation was minimal and the demand for oxygen was very low.