HEAT TRANSFER FROM CONDENSING STEAM TO VEGETABLE PIECES

Abstract
S: Vegetable pieces were suspended in a vertical 3 in. glass pipe through which steam passed at known temperature, pressure and velocity, and the center temperature of the piece was measured. Thc values for center temperature vs. time were used to estimate the surface heat transfer coefficient using Gurney‐Lurk charts. The volume of noncondensable gas in the vegetable affected the overall heat transfer coefficient. Reducing the volume of gas in the vegetable by vacuum degassing prior to heating increased the rate of center temperature rise, while increasing the volume of gas prior to heating by exposing the vegetable piece to nitrogen at 1500 psig decreased the rate. Steam velocities in the range of 0.1–2.6 ft/sec did not measurably affect the heating rate. However, when the velocity was increased further by using a nozzle, the rate of center temperature rise was increased.