| 摘要 |
PROBLEM TO BE SOLVED: To improve heat transfer performance, reduce the loss in transferred temperature difference between refrigerant and the vacuum steam of a condensed face, and also achieve an increase in the film heat transfer coefficient of a circulated heat medium for keeping excellent heat transfer performance and highly efficient steam condensation performance in a steam condenser in a vacuum dryer by increasing the width of the face where a refriger ant evaporating pipe and a metal plate contact each other by improving the lowering in the heat transfer caused by direct contact with the refrigerant evaporating round pipe of a trap so that the manufacturing of the steam condensation plate of the trap is prevented from becoming difficult. SOLUTION: The refrigerant evaporating round pipe of the steam condenser of a vacuum dryer to be inserted in the heat medium passage in a heat exchanger is transformed into an elliptical pipe 16 whose ellipse long axis is in parallel with a condensation scavenging face. By incorporating one or both of a pair of the flat faces formed by the transformation into the heat medium liquid passage (w) so as to be closely adhered to the inner face of the heat medium liquid passage (w), the area of the section where the refrigerant steam elliptical pipe 16 is adhered to the heat medium liquid passage (w) in a steam condensation plate (a) is increased, and by accelerating the convective film heat transfer of the heat medium liquid in the passage (w) of the heat exchanger, heat transfer performance and the condensation ability of vacuum steam are improved.
|
