R. Vance Morey

Equilibrium Relativity Humidity (ERH) Relationships for Yellow-Dent Corn

ABSTRACT Methodology for rapid collection of equilibrium relative humidity (ERH) data for grains and seeds has been developed. It is used to study the effects of variety, year grown, hysteresis and drying treatment on the ERH of yellow dent corn. Variety and year grown have a significant effect on ERH isotherms. Hysteresis occurs over almost all of the RH range although the amount of hysteresis decreases as moisture sorption temperature increases. The water adsorbing ability of yellow-dent corn decreases as the drying temperature increases. The interaction of drying treatment and rewetting significantly affects moisture sorption properties.

Moisture Diffusion Coefficients for Yellow-Dent Corn Components

ABSTRACT Anew procedure to determine the moisture diffusion coefficient data for corn components was developed. The diffusion coefficient data for corn components were modeled as a function of moisture content. It was found that the diffusion coefficient for the germ is the largest, followed by floury, and horny endosperm, and then by pericarp.

Practices for the Efficient Utilization of Energy for Drying Corn

ABSTRACT DATA and analyses are presented to evaluate alternatives for saving energy in drying shelled corn. These include: (a) adjustments in design and operating procedures for high-temperature dryers, (b) delaying harvest to allow additional drying in the field, (c) partial high-temperature drying.

Ambient Air Wheat Drying

ABSTRACT PERFORMANCE of ambient air wheat drying systems is simulated using weather data for St. Cloud, MN, Fargo, ND, and Grand Forks, ND. Evaluation criteria include energy use, completion date, moisture content distribution and dry-matter-decomposition. The results showed that operating the fan by humidistat control after the drying front reached the top of the bin, or shutting off the fan after September 15 when the drying front reached the top of the bin and completing drying in the spring, resulted in a reduction in energy use with deterioration levels comparable to continuous fan opera-tion. Dry-matter-decomposition levels increased rapidly above 19 percent moisture content.

Management of Ambient Air Drying Systems

ABSTRACT MANAGEMENT strategies for continuous and humidistat controlled operation are evaluated for single-fill procedures using simulation. Results also are presented for delay-fill procedures and bins equipped with stirring devices. Performance measures include grain deterioration (dry-matter-decomposition), final moisture content distribution, fan operation time and energy required.

Precooling of Fresh Market Broccoli

ABSTRACT BROCCOLI was cooled using forced air and hydro-cooling on a laboratory scale. Moisture loss and cooling rate were compared for the two methods. Less than one percent of the original broccoli weight was lost during cooling tests using air at or above 95% relative humidity. There was no significant difference in weight loss between forced air cooling and hydrocooling with comparable cooling media temperatures (within 0.5 °C or 1 °F) when measured 15 h after cooling. A single semilog plot of nondimensionalized average pulp temperature versus cooling time, with a slope of —0.022 min~S described the cooling rate for all tests including hydrocooling and forced air cooling at six different conditions.

Thin-Layer Drying Rates of Oilseed Sunflower

ABSTRACT THIN-LAYER drying rates of sunflower were determined experimentally as a function of oil content, drying air temperature and initial moisture content. The oil content had almost no effect on drying rate. The drying air temperature had the greatest effect, and initial moisture content had a small effect at the beginning of the drying test. The data closely fit a model suggested by Syarief et al. (1984) at the lower initial moisture content (26% d.b.), but not as well at the higher initial moisture content (33% d.b.) at drying temperatures of 27, 60 and 93°C (80, 140 and 200°F). New parameters developed for the model resulted in a good fit at both initial moisture contents..

Thin-Layer Equation Effects on Deep-Bed Drying Prediction

ABSTRACT MOISTURE content predictions from the deep-bed drying model of Bakker-Arkema et al. (1974) using a thin-layer equation developed by Li and Morey (1983) were compared to moisture contents measured in four laboratory experiments. Good agreement was obtained between predicted and measured results. Thin-layer equations developed by Thompson et al. (1968), Sharaf-Eldeen et al. (1979) and Misra and Brooker (1980) were also evaluated in the deep-bed model. Drying rates predicted with all of these equations were slower than the measured results. The effect of the thin-layer equation on design related results from the deep-bed model was illustrated.

Finite Element Model of Temperature Distribution in Broccoli Stalks During Forced-Air Precooling

ABSTRACT EXPERIMENTALLY determined thermal properties of a broccoH stalk were supplied to a simplified stalk heat transfer model—an axisymmetric finite element model—to simulate the temperature field of the stalk in a precooling process. Temperature differences between the simulated values and the values measured in a laboratory forced-air cooler were within 1.1 °C (5.6% of the initial temperature difference between the cooling air and the product).

Combination high-temperature, ambient-air drying.

ABSTRACT THE results of four years of high temperature, high-speed drying followed by in-storage, ambient-air dry-ing are presented. These results show that combination drying results in a reduction in propane or natural gas energy requirements compared to conventional high-temperature drying with in-dryer cooling. Electrical energy requirements are increased as a result of the in-storage phase of drying. In-storage drying performance using ambient air, supplemental solar heat and supplemental constant source heat is evaluated using computer simulation. The results show that ambient air pro-vides an efficient and effective means of drying. Addition of supplemental heat to the in-storage phase provides a modest increase in drying reliability. The total energy in-put for in-storage drying using supplemental heat from a fossil-fuel-derived source is significantly higher than with ambient-air drying.