THERMALLY INDUCED PRESSURES IN AN ON-FARM GRAIN STORAGE BIN

Thermally induced lateral pressures on the bin wall were measured arou nd the circumference (0.9 m above the bin floor) of a corrugated-steel bin (5.8 m in diameter, 6.2 m high). The bin was filled with wheat at 10.0 % moisture content (wet basis) to a depth of 5.0 m. Observed lat eral pressures varied diurnally, with lower pressure during the daytim e and higher pressure during the nighttime. The distribution of therma l pressure around the bin circumference was non-uniform during the day time hours and was uniform during the nighttime hours. The thermal pre ssure per unit decline in wall temperature did not vary significantly (P<0.05) around the bin circumference during either the daytime or the nighttime hours. The average thermal pressure increment was 114 Pa/de grees-C for a range of bin wall temperature from -11-degrees-C to -29- degrees-C.