The oscillating vane-type fan

摘要

The investigation herein described was undertaken to determine the performance characteristics of the oscillating vane-type fan. The fan was the invention of Mr. Van Dorn and Mr. Cornwell, primarily for use in circulating air in railroad refrigerator cars. In the present system of railroad refrigeration for the transportation of perishable foodstuffs, the refrigerator car is a heat insulated car, with bunkers at each end for the cakes of ice. When the car is loaded and the doors shut, cooling is obtained only due to the natural circulation of air in the car, caused by the difference in temperature between the ice in the bunker and the fruit. This circulation has not been found sufficient, in that there is a large temperature difference between the top and bottom fruit (see Appendix B) and the top half is too warm, often spoiling during transportation. Also, because of this, the car cannot be filled to its volumetric capacity. Therefore the requirements which led to the invention of this type of fan were as follows:udud1. To provide a sufficient volume of air, against the resistance developed in passing through the fruit, to obtain the cooling characteristics required.udud2. To provide a fan which would not require major changes in the structural design of the car, or lessen the amount of fruit which could be carried.udud3. To provide a fan, simple in construction and installation, and in its drive mechanism from the car axle.ududThe oscillating vane-type fan met conditions 2 and 3 in that it could be situated in the four and one half inch space between the floor racks and the floor of the car, through which the air naturally circulated, and in that it could be driven by a simple wheel and crank drive directly off the axle. This thesis presents the results of the investigation of the first condition.ud