K. Alagusundaram et al., DISTRIBUTION OF INTRODUCED CARBON-DIOXIDE THROUGH STORED WHEAT BULKS - A PILOT-SCALE STUDY, Canadian agricultural engineering, 38(2), 1996, pp. 83-89
The distribution of introduced carbon dioxide (CO2) was measured exper
imentally in three 1.42-m-diameter bins containing wheat to a depth of
1.37 m. Dry ice was used as a source of CO2 gas. The effects on the d
istribution of CO2 of the floor opening (circular near the centre, rec
tangular, and circular near the wall), the grain surface left open or
covered with a polyvinylidene chloride (PVDC) sheet, and the mass of i
ntroduced dry ice were studied. The CO2 gas moved more rapidly in the
horizontal direction than in the upward vertical direction. Although t
here were gradients in the vertical direction, the CO2 concentrations
were nearly uniform in the horizontal direction in the top two-thirds
of the wheat bulks. The efficiency of retention (the ratio of the mass
of CO2 retained in a bin to the total mass of CO2 input, eta(r)) was,
on average, 6 percentage points greater when the grain surfaces were
covered with the PVDC sheet than when grain surfaces were open. The ma
ximum observed eta(r) was only 55%.