0 Replies Latest reply on Sep 9, 2014 5:52 AM by Andres Tretiakov

    Plastic bin rocket using liquid nitrogen

    Andres Tretiakov

       

      About 200 ml of liquid nitrogen at -196 degrees Celsius were poured carefully using cryogenic protective gloves into a 2 L plastic soda bottle. Then wearing goggles and face shield the plastic cap was screwed tightly back on the bottle and dropped into a plastic bowl filled with some water. Immediately after that, a 75 L plastic refuse bin was placed upside down over the smaller bowl.

      After a few seconds and having retreated to a safe distance, a loud bang was heard and the bin was propelled high into the air (about 10 metres).

      This is a perfect example of the BLEVE (Boiling Liquid Expanding Vapour Explosion) principle or effect. When liquid nitrogen is confined in a sealed bottle, the gases start to expand in the container since it is constantly boiling and pressure inside the bottle starts building up. About one ml of liquid nitrogen turns into 700 ml of nitrogen gas (that is quite a lot!). The soda bottle can only withstand about 10 atmospheres of pressure (or ~150 psi) sometimes called maximum operation pressure or MOP and beyond this limit, it will burst in this case by exploding.
      The force from the rapid explosion causes the launching of the bin up in the air and destroys the smaller plastic bowl in the process. 

      WARNING:
      This explosion can be very loud and pieces of plastic from the bowl and bottle may go flying all over, although most are contained under the big bin. Nevertheless, keep your distance and cover your ears!!!!