Sunday, August 12, 2018

This is something many of us did not know!!!!


Microwaving  Water!

Ed. This is something I sure didn’t know. I’m passing it along to other Coach’s Team readers who heat water for tea or coffee.

Hat Tip: karinsue1

A  26-year old man decided to have a  cup  of coffee.  He took a  cup of water and put it in the microwave to heat  it up (something that he had done numerous times  before). I am not sure how long he set the timer  for, but he wanted to bring the water to a boil.  When the timer shut the oven off, he removed the  cup from the oven. As he looked into the cup, he  noted that the water was not boiling, but  suddenly the water in the cup 'blew up' into his  face. The cup remained intact until he threw it  out of his hand, but all the water had flown out  into his face due to the build-up of energy . His  whole face is blistered and he has 1st and 2nd  degree burns to his face which may leave  scarring.

He also may have lost partial  sight in his left eye. While at the hospital,  the doctor who was attending to him stated that  this is a fairly common occurrence and water  (alone) should never be heated in a  microwave  oven. If water  is heated in this manner, something should be  placed in the cup to diffuse the energy such as  a wooden stir stick, tea bag, etc, (nothing  metal).

General  Electric's Response:

Thanks  for contacting us; I will be happy to assist  you. The e-mail that you received is correct.  Microwaved water and other liquids do not always  bubble when they reach boiling point. They can  actually get superheated and not bubble at all.  The superheated liquid will bubble up out of the  cup when it is moved or when something like a  spoon or tea bag is put into it.

To  prevent this from happening and causing injury, do not heat any liquid for more than  two minutes per cup. After heating, let  the cup stand in the microwave for thirty  seconds before moving it or adding anything  into it.

Here is what a local high school science teacher had to say on the matter:

'Thanks for the microwave warning. I have seen  this happen before. It is caused by a phenomenon  known as super heating. It can occur any time  water is heated and will particularly  occur if the vessel that the water is heated in is new, or when heating a small amount of  water (less than half a cup).

What  happens is that the water heats faster than the  vapor bubbles can form. If the cup is very new, then it is unlikely to have small surface  scratches inside it that provide a place for the bubbles to form.  As the bubbles cannot form and  release some of the heat that has built up, the  liquid does not boil, and the liquid continues to heat up well past its boiling  point.

What then usually happens is that the liquid is bumped or jarred, which is just  enough of a shock to cause the bubbles to rapidly form and expel the hot liquid. The rapid  formation of bubbles is also why a carbonated  beverage spews when opened  after  having  been shaken.

 
If  you pass this on, you could  very well save someone from a lot of pain and  suffering.


No comments:

Post a Comment