No description available.

Two slotted two-dimensional spouted bed units with flexible bed dimensions were designed and fabricated. Static vertical pressure of grains (shelled corn, soybean, and wheat) on the air entry slots in the pilot scale unit indicated that the silo theories are not applicable to predict this pressure accurately without including the bed to air inlet aspect ratio, slant angle, and sphericity of grains. A grain quantitative factor accounting for emptying angle of repose and sphericity of particles was proposed and included with the collected data to develop an empirical regression model. / Aerodynamics of grains (shelled corn, soybean, and wheat) were found to be affected by slant angle, spout width, separation distance, length of bed and the bed geometrical similarity. Mathematical models for the design parameters of the spouted beds were developed following the principles of dimensional analysis and similitude. Model predictions agree closely with the data. / The drying rate of shelled corn in the geometrically similar two-dimensional spouted beds with draft plates was found to depend on the bed geometry and operating parameters. The drying characteristics of corn in the investigated spouted beds was found to be of the thin layer type. The performance of dryers was modeled in the form of the Page's equation. Expressions for the model parameters accounting for bed geometry, grain moisture content, and drying conditions were developed. The developed model predictions agree well with the data from both beds.

No description available.

The potential of granular zeolites as a heating medium for drying corn was evaluated in a batch type experimental dryer. At temperatures from 150-250$ sp circ$C and residence times of 3-8 minutes, synthetic zeolites (4A and 13X) removed 9-18 percentage points from the initial moisture of corn. These values were about double those of sand, the most commonly used particulate medium. / Using an adiabatic dryer, the kinetics of moisture sorption in corn-zeolite mixtures was investigated. The heating medium in this part of the study was a natural zeolite (chabazite) and the corn was yellow dent type. Diffusivity values for corn were 1.012 $ times$ 10$ sp{-5}$ $-$ 3.127 $ times$ 10$ sp{-5}$ cm$ sp2$/s with zeolite at temperatures of 140-220$ sp circ$C. These values are much smaller than those for zeolite. Therefore, it is believed that the diffusion of moisture in corn itself is the main resistance to the transfer of moisture. The heat transfer coefficient between corn and zeolite was found to be in the range of 50-312 W/m$ sp2 cdot$K. Luikov's model for simultaneous heat and mass transfer was applied to corn-zeolite mixtures and the equations were solved by the Numerical Method of Lines (NMOL). These numerical solutions agreed closely with the experimental data. / The processed corn was subjected to in vivo and chemical analyses. Results of feeding experiments using laboratory rats did not indicate that the nutritive quality of the processed corn was adversely affected. Similarly, the acid detergent fibre analysis did not show a significant reduction in the availability of corn protein.

Southern pine and Douglas fir veneer samples were dried in air under the following conditions: air temperatures were 350, 600, and 750°F; air velocities were 50, 100, and 150 feet per second, and angles of impingement of air against the veneer surfaces were 0°, 45°, and 90°. The resulting drying curves were compared with drying curves obtained under similar conditions using steam as the drying medium. Statistical analyses were performed to estimate magnitudes of differences in veneer drying times associated with the two drying media, the three angles of impingement, and the two species of wood. Air was found to be more effective than steam as a drying medium at the 350°F operating temperature. For the 600°F and higher operating temperatures, steam was found to be more effective than air. Under all drying conditions, Southern pine dried faster than Douglas fir. Effective heat transfer coefficients representing the convective effects of both heat and mass transfer associated with drying veneer were computed in two ways: based on the experimental data, and based on theoretical considerations. Experimental internal diffusion coefficients were also computed. Diffusion of water from the interior of the veneer to the veneer surfaces was found to be the controlling factor on the rate of veneer drying during all but a brief period in the initial stage of the drying process. / Graduation date: 1970

Commercial utilization of pollinizing varieties of pears is important both for pear growers and processors in Oregon. A study was made to determine the suitability of Comice, Packam's Triumph and Anjou, the three pollinizing varieties of pears, for dehydration, as compared to the Bartlett variety which is commercially used for dehydration. These four varieties were dehydrated using conventional and dry-blanch-dry methods and were subsequently stored at 70°F. The storage period of Bartlett, Comice, Anjou, and Packam's Triumph was 275, 212, 186 and 175 days, respectively. Both fresh and dehydrated pears were analyzed for moisture, total acid, and total sugar. The over-all drying ratio and rehydration percentage of each dehydrated lot was determined. After storage, the dehydrated pears were evaluated for flavor, texture, color, over-all appearance, and over-all desirability by a panel of eight judges. The results indicated the following conclusions. (1) There was no significant difference in the over-all drying ratio of the unpeeled dried pears of all four varieties and treatments. (2) Peeled dried Packam's Triumph had the highest over-all drying ratio followed by Anjou, Comice, and Bartlett, respectively. (3) Bartlett had the highest rehydration percentage followed by Anjou, Comice, and Packam's Triumph, respectively. (4) There was no significant difference in the rehydration percentage of conventionally dried unpeeled and dry-blanch-dry unpeeled pears. But dry-blanch-dry peeled pears had a significantly higher rehydration percentage than the conventionally dried peeled pears. (5) The dehydrated Anjou pears had the lowest total sugar content of all four varieties. Packam's Triumph had a higher total sugar content than Anjou but lower than Comice and Bartlett. The total sugar content of the latter two varieties did not vary significantly. (6) The dehydrated Anjou pears had the highest total acid content of all the four varieties. Packam's Triumph had lower total acid content than Comice and Bartlett. The total acid content of the latter two varieties did not vary significantly. (7) The flavor, texture, and over-all appearance of all dehydrated lots did not vary significantly. The flavor and texture of all lots were liked by the panel, but the over-all appearance of these lots was disliked by the panel. (8) The color of peeled dried pears was rated higher than unpeeled dried pears by the panel regardless of variety and method of dehydration. The panel liked the color of dry-blanch-dry unpeeled and peeled pears more than corresponding conventionally dried unpeeled and peeled pears. The color of Comice and Anjou was rated higher than Bartlett and Packam's Triumph by the panel. The color of the latter two varieties was disliked by the panel. (9) The over-all desirability of all four varieties was rated higher than average by the panel. / Graduation date: 1965

Graduation date: 1948

Graduation date: 1948

Graduation date: 1972

Graduation date: 1968