How Does a Vacuum Bottle Work? A vacuum bottle is a bit like a super-insulated jug. It works by insulating whatever is stored in it. A vacuumbottle (sometimes called a Thermos) is really a bottle within a bottle. Most of the air has been pumped out of the space between the bottles, thereby creating a vacuum.
Heat cannot travel easily through a vacuum. Some heat does get through the vacuum by radiation. Much of this heat, however, is blocked by the bottle’s shiny, silvery coating, which is designed to reflect heat. By shutting the heat in or out, the vacuum bottle helps keep cold liquidscold and hot liquids hot.
Whether you like your coffee piping hot or icy cold, vacuum bottlesare an absolutely brilliant way to keep your drinks just the way you want. Some heatstill escapes (or gets in) eventually, mostly through the stopper, but flasks or thermos like this are still a vast improvement on almost every other kind of insulated drinks container. In conclusion we do know now how does a vacuum bottle work.
Why do flasks explode? We suspect a crack or leak in the flask caused the explosion. When a flask partly open to the atmosphere is immersed in liquid nitrogen, air is condensed. When the flask is removed from the liquid nitrogen, the pressure can build quickly due to the phase change from liquid to gas causing the glass to shatter.
Content for this question contributed by Janet Wagner, resident of Pittsburgh, Pennsylvania, USA