The stainless steel vacuum flask suddenly loses heat preservation, which should be related to the quality of the product; if it is within the shelf life of the product, it can be replaced with the seller in time. The thermos cup is developed from the thermos bottle. The principle of heat preservation is the same as that of the thermos bottle, but people make the bottle into a cup for convenience.
Simple identification method of vacuum insulation performance:
(1) Pour boiling water into the thermos cup and tighten the cork clockwise, or touch the outer surface of the cup body with your hands after 2 to 3 minutes. If the cup body is obviously warm, it means that the product has lost its vacuum. Can not achieve good thermal insulation effect. The outside of the insulated cup is always cool.
(2) See if the internal seal is tight. Check whether the screw plug and the cup body fit properly, whether the cup lid can be screwed in and out freely, and whether there is water leakage. Fill a full glass of water and turn it upside down for four or five minutes or shake it a few times to verify that there is no leak.
Stainless steel thermos cups are mainly divided into: ordinary thermos cups (the heat preservation time is generally less than 3 hours after boiling water is poured in), vacuum thermos cups (through the vacuuming process, the boiling water can be kept warm for more than 8 hours).
1. The main reason why the thermos cup does not keep warm is that the vacuum layer between the two shells is destroyed. It used to be a vacuum inside, but now there is air inside. Therefore, the thermos cup will lose the function of heat preservation.
2. The principle of the vacuum flask is the same as that of the thermos. They all use a double-layer shell, and the air between the two-layer shells is extracted to become a vacuum environment. The heat transfer ability of the vacuum is very poor, so that the The convection and conduction of thermal energy are greatly reduced.
3, a good thermos cup, fortunately, the cup lid. It can be said that the thermal insulation performance of the thermos cup is determined by the thermal insulation performance of the bottle cap. Many common thermos cups are polished on the inside of the cup, so that thermal radiation infrared rays can be refracted. Keep the heat energy inside the cup as much as possible.
Post time: Mar-01-2022