Tweedpipe

Brilliant.
I've just ordered one for my moles...........

bigglesworth

Novocastrian.

Thank you for the lucid reply. So by extension a 13 (excluding container) kilo bottle of gas should contain about 295 litres of gas?

Grannybunz - what a great little gadget. I have ordered three! Thank you.

Novocastrian

Err... I think your calculator's on the blink. Mine says 6,233 litres for 13 kg.

bigglesworth

Novocastrian

yes i see i miscalculated but something is not right.
Aga Rayburn say their range cookers use 3.6 litres gas every 5 hours if used for cooking, central heating and domestic hot water so 17 litres a day.
So one 13 kilo bottle would last a year. or am I missing something?

Novocastrian

I'm guessing the weight includes the bottle. Have you weighed a full one and an empty one? (I'm on town gas so I've no idea).

bigglesworth

not specifically, but an empty one is a heck of a lot lighter. it is possible there is only 10 kilos of gas but still cannot be right

BTW apolgies for curt responses - swimming accident has disabled my typing hand

Novocastrian

Nothing curt at all and sorry about the hand.

Thinking about it a bit I'm not sure what Aga mean by "uses 3.6 litres in 5 hours".

It being a Friday afternoon where I am, I've just looked up the heat of combustion of propane and its 2200 kJ/mole. Now 3.6 litre (if they mean litre of gas at standard temperature and 1 atmosphere pressure is only 0.16 Moles (steady on Tweedpipe, still not that sort of mole), so burning that amount would release 350 kJ of energy in (5x60x60) = 18000 seconds. This would mean the power in Watts (= joules per second) is only about 20W i.e. that of a rather dim light bulb.

As you say, something's wrong. Could they mean 3.6 litres at tank pressure? I just don't know.

On edit: D'oh! Propane bottles contain liquid propane don't they? Not gas. Mr. Google tells me the density of liquid propane at 25C is 0.493 gm/cc or 0.493 kg/litre. If they mean 3.6 litres of the liquid then I think everything makes just about sense.

Just visualizing a small (13 kg?) propane tank suggests that the volume of the tank which I calculate from the above to be 26.4 litres is about reasonable.

By George, I think we've got it!

bigglesworth

I always say - all human knowledge is there1

Thank you

Novocastrian

That's OK. I learned something new too. For example I learned that I owe an apology to the first poster who replied on the thread (Jammy James). In retrospect it's clear that the volume of 91.8 litres he (correctly) said was in a 47 kg tank referred to the volume of liquid propane, not as I assumed the volume of propane gas.

A little knowledge can be a dangerous thing.

kazzo

Does anyone know if the moles survived?

Novocastrian

Your lack of edumacation is hanging out.

kazzo

I like to hide my edumacation under a bushel with my mole!

Jon-Bxl

No he doesn't mean that kind of mole.. although if you pumped their holes with gas and set it alight - you might get rid of the molehills in the garden

But don't worry the other type of 'mole' isn't a worry, this is a public forum, so no secrets to reveal

cjm

I'd love to know how many moles died to make my moleskin trousers

Novocastrian

Three. One for each leg.

Of course, it depends on the species of mole. The one in MI5? Perhaps the one on Madame Bovary's cheek? The ones under the lawn? Or the ones I was referring too?