Browsing by Author "Wilcke, William F."

Now showing 1 - 4 of 4
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    Forced-Air Produce Cooler
    Wilcke, William F.; Stiles, Herbert D. (Virginia Cooperative Extension, 2015-01-28)
    This is a plan for a simple device you can build yourself to speed cooling of non-wrapped produce packed in vented cartons. The cooler is designed for small fruits, but can be easily adapted for other products.
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    Forced-Air Produce Cooler
    Wilcke, William F.; Stiles, Herbert D. (Virginia Cooperative Extension, 2009-05-01)
    This is a plan for a simple device you can build yourself to speed cooling of non-wrapped produce packed in vented cartons. The cooler is designed for small fruits, but can easily be adapted for other products.
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    Simulation of a swine nursery to facilitate economical management
    Harmon, Jay David (Virginia Polytechnic Institute and State University, 1989)
    Two deterministic simulation models were developed to assess the economics of swine nurseries. The first model assessed the emergency needs of swine nurseries by simulating the temperature response during a short term power failure. The failure model accounted for heat exchange by conduction, convection, radiation, and air infiltration. An existing sub-model was used to predict swine heat and moisture loss. The failure model was validated using a nursery constructed of concrete block. It performed well for cases with constant solar load, but tended to overpredict temperature changes during periods of no solar load. Validation indicated accurate wall-characteristic and wind velocity estimations were crucial to obtain accurate model results. The second model was developed to describe the normal operation of swine nurseries by predicting pig growth and feed consumption, building fuel consumption, and cost per unit of gain produced. lt was based on an existing swine model that was converted to an hourly basis. An optimization option was incorporated into the operational model to allow minimization of the cost per unit of gain. The operational model was validated and found to accurately predict feed consumption and growth during a one week time frame. Fuel consumption was less accurate. The optimization mode predicted considerable cost savings for operation at lower temperatures.
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    Simulation of deep-bed drying of Virginia peanuts to minimize energy use
    Kulasiri, G. Don (Virginia Tech, 1990-11-05)
    A deep-bed drying model simulating the drying of peanuts in a fixed bed is required for designing energy-efficient and automatically controlled dryers. A deep-bed drying model consists of a thin-layer drying model to calculate the moisture release from the material and a set of mass and energy balances. An experimental setup was constructed to determine drying rates of Virginia-type peanuts under 14 different drying air conditions. Selected empirical and semi-theoretical models available for modeling thin-layer drying rates were fitted to the collected data using nonlinear regression techniques. The modified Page's model and the two-term exponential model fitted the data better than other models considered. A deep-bed drying model PEATECH based on four coupled partial differential equations consisting of four variables, air temperature, peanut temperature, air humidity, and peanut moisture content was developed. Validation of the model was accomplished by using the data collected from 36 deep-bed drying experiments conducted using three laboratory dryers during 1987, 1988, and 1989. PEATECH predicted the variables within a peanut bed with an accuracy of less than ± 6%. The energy saving potential of exhaust-air recirculation was established by conducting simulated experiments using a modified version of PEATECH.