| 摘要 |
PURPOSE:To obtain a uniform distribution of temperature at a bottom of an underground storage tank, by forming a plurality of radially extending water channels in concrete constituting the bottom of the underground storage tank, and forcibly supplying hot water through these water channels. CONSTITUTION:The water in a pit 6 is circulated by a pump 15 to a heat exchanger (not shown) via a circulation passage 17 so as to be heated to a predetermined temperature. The resulting hot water is supplied under pressure to a water feed passage 12 through a hot water supply pipe 16. The hot water is then ejected from nozzles 13 into water channels 9. A bottom wall 5 is heated with the hot water flowing in the water channels 9. The hot water flowing in the water channels 9 is collected in a water accumulator 10 provided in the central portion of the bottom wall 5 so as to be returned to the pit 6 through a collected water return pipe 11. As a result, the bottom wall 5 is heated entirely with the circulated hot water so that the distribution, of temperature at the bottom wall 5 necessarily becomes uniform. |
