| 摘要 |
PURPOSE:To prevent acting of uneven load to an underground cold tank, by attaching a heating means of the type increasing its electric resistance with rising of the temperature to a required number of conduits which are extended along the side wall of the tank, and thereby making the peripheral freezing uniform. CONSTITUTION:Since the peripheral temperature of an underground tank near the side wall 6a and the bottom surface located on the side of the sea S is higher than that near the side wall 6b located on the side of the land L, the temperature of a surface heater 5 at the portion 5a located on the side of the sea S is higher than that at the portion 5b located on the side of the land L. Therefore, electric current passed through the portion 5b of the surface heater 5 is made greater than that passed through the portion 5a, so that the portion 5b produces more heat than the portion 5a and the difference of temperature on the side of the sea S and that on the side of the land L can be compensated. Resultantly, uniform freezing is caused around the entire periphery of the tank, so that uneven load is not acted to the tank. |
