Operating Aeration Systems

Minimal Thermal Requirements for Development and Activity of Stored Product and Food Industry Pests (Acari, Coleoptera, Lepidoptera, Psocoptera, Diptera and Blattodea): A Review

“…Beckett [14] stressed that the LDT is lower than the LPT, and Howe [26] estimated that the LPT values are approximately 3–5 °C above LDT values in most storage arthropod pest species. Minimum population thresholds may be less precise in estimation—due to their inherent higher complexity—than the LDT, but the LPT is more convenient for usage in storage practice, especially for creating strategies to protect stored grains from pest population increases by cooling and ventilation [34].…”

“…Apart from drying, decreasing temperature is a fundamental concept for the pest-free storage of commodities without pesticides. There are multiple research papers and reviews regarding active aeration and cooling systems in silos and flat grain stores and how to quickly, evenly and economically decrease temperature in commodity masses (e.g., [14,34,71,72,73]). Aspaly et al [46] proposed a model based on LPTs that shows a safe storage period during winter and spring seasons.…”

Airflow resistance of wheat bedding as influenced by the filling method

“…In practice, local changes of the airflow resistance in various areas of grain bulk may cause serious disturbances in processes involving the flow of gases such as aeration, drying, fumigation, or cooling. According to Navarro and Noyes (2002) the values of airflow resistance calculated by means of the proposed equations or taken from tables correspond to clean, loosely packed grain and apply to vertical direction of airflow and, in consequence, are usually lower than in practical conditions. These authors pointed out that the efficiency of the aeration systems depends to a large extent on a uniform distribution of the airflow within the volume of grain.…”

Investigation on compression and mildew of mixed and separated maize

“…First, coupled heat and moisture transfer in grain bulk has been studied extensively and valuable results have been obtained such as natural convection by Khankari et al ( 1994 ) and Wang et al ( 2016 ), and the ventilation drying process by Thorpe ( 2008 ) and Panigrahi et al ( 2019 ). Furthermore, some researchers confirmed that segregation led to non‐uniform airflow distribution, which further resulted in higher temperature and higher relative humidity in zones with low airflow in the same silo (Navarro & Noyes, 2001 ; Yue & Zhang, 2017 ). Most researchers are devoted to the study of heat and moisture transfer in grain bulk (Hammami et al, 2016 ; Wang et al, 2016 ) and the relationship between segregation and airflow resistance (Lawrence & Maier, 2011 ).…”

“…However, the above research have neither considered the combined effect of kernel breakage and its induced segregation on mildew nor there is information in the literature about the relationship between the compression of broken maize kernels due to vertical loading and mildew. On one hand, breakage played a major role in the density distribution (Navarro & Noyes, 2001 ) and the redistributed density further affects the thermal conductivity. It was well known that with increasing bulk density, the thermal conductivity increased accordingly because the contact area between kernels influences heat transfer (Chang, 1986 ; Cheng et al, 2017 ), resulting in the redistribution of moisture content and heat in the grain bulk.…”