Brace Fan Cold Gassing for Refrigerated Railroad Car Sulfur Dioxide Fumigation of Grapes

Abstract

A method was developed whereby refrigerated railroad cars of grapes could be fumigated with sulfur dioxide without using a hot-water bath to vaporize the fumigant. The liquid SO₂ could be vaporized inside rather than outside the car by using an atomizing spray nozzle. The gas could be distributed evenly to the fruit provided a brace fan was used. An air charge of 100-200 lb per square inch in the SO₂ cylinder is recommended to develop adequate pressure to atomize the fumigant satisfactorily, particularly where the cylinder temperature is apt to be lower than room temperature when delivering the gas.