Tea, anyone?
Thread Starter
Tea, anyone?
I see in Flight Global that BA is to introduce a new blend of tea which tastes as good in the air as it does on the ground, compensating for the fact that water boils at 8000 ft cabin altitude at about 92 deg. C.
In my new home I have device called a Quooker, which gives instant boiling water (and a fine cup of tea without boiling the kettle !) I believe this device actually produces boiling water at a temp. ABOVE 100 c as it is pressurised to above ambient.
Are there any technical reasons why we couldn't have such a device on an aircraft with the pressure in the device at or above MSL pressure, and decent cup of English breakfast
(Well, it makes a change from 787 batteries !!)
In my new home I have device called a Quooker, which gives instant boiling water (and a fine cup of tea without boiling the kettle !) I believe this device actually produces boiling water at a temp. ABOVE 100 c as it is pressurised to above ambient.
Are there any technical reasons why we couldn't have such a device on an aircraft with the pressure in the device at or above MSL pressure, and decent cup of English breakfast
(Well, it makes a change from 787 batteries !!)
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http://www.quooker.dk/dk/img/Energir...april-2010.pdf
In an aircraft at altitude you would probably have to turn the temperature down because if you put water at say 98C into a cup when the local boiling point is only 92 it's going to bubble away like mad...that is if you can get the water into the cup without it turning to steam as it comes out of the tap?
..there is a danger of ‘superheating’, especially when using very smooth, scratchless surfaces, e.g. a new tea glass, and especially when the water has been previously heated and most of the dissolved gases have been driven out. The liquid does not find any irregularities that can serve as a nucleus for forming water vapour bubbles and actually will not ‘ bubble’ easily. The temperature can then rise above the boiling point (e.g. 101 °C). Once the cup is picked up or the surface is slightly stirred by adding a substance (coffee, tea) this one degree of superheating results in instantaneous flash-evaporation of water (amounting to about 3 litre of water vapour per litre water of 101 °C), causing the boiling water to splash from the cup possibly causing serious burning injuries.
Indeed - it's dangerous. We recently had a case of a passenger being badly burned when she opened a thermos flask she had bought aboard without security noticing. When opened, the pressure drop caused the liquid inside to reach a new low boiling point covering her in scalding water.
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@ cwatters, Retired BA/BY,
I am in extreme trouble when I read English PPRuNers would prepare my favorite VFTOP Darjeeling with boiling water .
Thank Our Lord he helps the stewardess to avoid such shame...
To do "tea" undrinkable, use water over 60°c, wait more than 3-5 min to drink it, use more than one teaspoon for one cup of tea, use bad water or already preboiled water.!
No wonder pilots crash the aircraft, and passengers are terrified in flight if you are over boiling water with pressure... and insurance refuse to pay damage!
I am in extreme trouble when I read English PPRuNers would prepare my favorite VFTOP Darjeeling with boiling water .
Thank Our Lord he helps the stewardess to avoid such shame...
To do "tea" undrinkable, use water over 60°c, wait more than 3-5 min to drink it, use more than one teaspoon for one cup of tea, use bad water or already preboiled water.!
No wonder pilots crash the aircraft, and passengers are terrified in flight if you are over boiling water with pressure... and insurance refuse to pay damage!
Last edited by roulishollandais; 12th Feb 2013 at 10:26.
Thread Starter
Ah well, that puts paid to that then, twas just a thought !
Back to 787 batteries !! ( and in mho likely to be a problem of charging and unbalanced cells based on my experience of, much smaller but same chemistry and similar pack composition, Lithium ion and lithium polymer batteries).
Back to 787 batteries !! ( and in mho likely to be a problem of charging and unbalanced cells based on my experience of, much smaller but same chemistry and similar pack composition, Lithium ion and lithium polymer batteries).
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Try a Kenyan variety, something like a nilgiri in a broken orange pekoe leaf if your normal preference is English Breakfast. It's stronger and more bitter than the Ceylon/Assam blend which is a good EB, and likely to come close to the flavour you want.
The Georgian "Chai" type blends are/were used I think by Aeroflot, and should give something very similar to a Darjeeling.
P
The Georgian "Chai" type blends are/were used I think by Aeroflot, and should give something very similar to a Darjeeling.
P
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Have used a pyrex jug to heat water in the Microwave, on many occasions. Leave it "cooking too long, you get exactly the same results as outlined above. It's often possible to take the jug of water out of the oven and place it gently on the work surface...get an ordinary fork and touch the surface....a quite violent eruption can ensue 
A half a grape stuck in the microwave on full power will produce a floating ball of Plasma (burning "stuff" ) fascinating to watch, just make sure the Distaff side of the family doesn't catch you.
A half a grape stuck in the microwave on full power will produce a floating ball of Plasma (burning "stuff" ) fascinating to watch, just make sure the Distaff side of the family doesn't catch you.
