Construction and evaluation of a bale weighing gantry

Development of a more precise method of determining drying rate parameters was the main objective of this experiment. Therefore, a bale weighing gantry was designed to meet this need. The gantry was designed to suspend four large, round, hay bales so that their weights could be continuously monitored while the bales were drying. The bale weighing gantry was constructed and assembled using research facilities of the Biosystems Engineering Department at The University of Tennessee, Knoxville. After the gantry had been successfully constructed and assembled, it was shipped to the Middle Tennessee Experiment Station for testing in the solar-heated forced-air dryer located there. The gantry was tested using large, round bales that had 6-inch and 12-inch hollow cores. Bales dried on the solar dryer floor consisted of solid, 6-inch hollow core, and 12- inch hollow core bales. Drying rate parameters were determined by taking core samples of bales on the dryer floor and monitoring weight of bales suspended by the gantry.

The gantry did provide a more precise method of determining drying rate parameters. The gantry method had a significantly lower standard error associated with the predicted drying rate parameter than did the core sampling method (P<.001). No statistically significant differences were found in the drying rate parameters of the solid, 6- inch hollow core, and 12-inch hollow core bales (P>.11). The 12-inch hollow core bales suspended by the gantry tended to have higher drying rate parameters than did the 6-inch hollow core bales but is not supported statistically (P>.13). Two types of fans were used in the drying process. Inline centrifugal fans produced significantly faster drying rates compared to the vane-axial fans (P<.05). Results showed that there was no significant loss of bale dry matter during the drying process of the experiment (P<.001).