| 摘要 |
PURPOSE:To reduce infiltration of heat into a tank, by providing the first heat preventing layer in the upper internal surface of a skirt while the second heat preventing layer in the upper peripheral surface of the skirt and constituting the skirt using a material of small heat conductivity in the vicinity of a position where these heat preventing layers are opposed. CONSTITUTION:A skirt 16 contains a skirt part l6 consisting of the same mate rial to that of a tank 15, skirt part l7 consisting of a material like stainless steel with heat conductivity smaller than that of the skirt part l6 further with an excellent low temperature resisting property and serving as a thermal brake and skirt part l8 made of steel. The first heat preventing layer 25, which prevents heat from infiltrating, is mounted to the peripheral surface in the bottom part of the tank 15 surrounded by the skirt 16. While the second heat preventing layer 28 is provided from the peripheral surface in the upper part of the skirt 16 over the upper part of the tank 15 in the upper of the shirt. |
