Vagueness and the Aftermath - A sporadic diary

[rex008]

A 900w microwave uses about 1500w of power - but like doubleup says, it will use that 900w (of microwave power) very efficiently.

I think some empirical research is required Tom - get experimenting and tell us your findings!

An engine generator is typically around 60% efficient, so combined with the microwave, you end up with about 35% of the combustion energy of the propane going into your soup.

Now, how efficient is lighting a flame under your bowl? A quick google gives a number of 50% efficiency for a gas hob. That's one number off one site and I suspect there are several variables. However, I think that probably answers the question.

I'm going to correct myself - the generator % was for a diesel generator; it's quite hard to get numbers, but a propane generator runs at <30% efficiency from what I can find. Which makes the case for a gas hob even more convincing.

I wonder.

If we could route the hot exhaust gasses from the generator through the cooking compartment of the microwave, would that redress the balance?

Would certainly help, although given the volume of exhaust gases produced, the average residence time in the microwave chamber would be small.

Say it's a 50cc 4stroke engine, running at 3000rpm (pure guesses), that's 50cc*1500 / min = 1.25 litres of gas per second (assuming 100% volumetric efficiency, quite likely). Say microwave is about 25 litres (typical), that means your exhaust passes through the oven in about 20s. Actually, that's not bad, you'd get reasonable heat exchange in that time.

But your soup may taste a bit funny.

Just to return to this for a moment, have we taken into consideration the fact that the gas hob has to heat the container before it can heat the soup?

I'm not sure what the 50% number includes, to be honest. But the microwave will the heat the container to a certain degree, just not so much. And the heat required to heat a metal saucepan is fairly low compared to the liquid contents (factor of 10 by weight - water has a huge specific heat capacity compared to most other things, especially heavyish metals).

[RED-DOG]

A 900w microwave uses about 1500w of power - but like doubleup says, it will use that 900w (of microwave power) very efficiently.

I think some empirical research is required Tom - get experimenting and tell us your findings!

An engine generator is typically around 60% efficient, so combined with the microwave, you end up with about 35% of the combustion energy of the propane going into your soup.

Now, how efficient is lighting a flame under your bowl? A quick google gives a number of 50% efficiency for a gas hob. That's one number off one site and I suspect there are several variables. However, I think that probably answers the question.

I'm going to correct myself - the generator % was for a diesel generator; it's quite hard to get numbers, but a propane generator runs at <30% efficiency from what I can find. Which makes the case for a gas hob even more convincing.

I wonder.

If we could route the hot exhaust gasses from the generator through the cooking compartment of the microwave, would that redress the balance?

Would certainly help, although given the volume of exhaust gases produced, the average residence time in the microwave chamber would be small.

Say it's a 50cc 4stroke engine, running at 3000rpm (pure guesses), that's 50cc*1500 / min = 1.25 litres of gas per second (assuming 100% volumetric efficiency, quite likely). Say microwave is about 25 litres (typical), that means your exhaust passes through the oven in about 20s. Actually, that's not bad, you'd get reasonable heat exchange in that time.

But your soup may taste a bit funny.

Just to return to this for a moment, have we taken into consideration the fact that the gas hob has to heat the container before it can heat the soup?

I'm not sure what the 50% number includes, to be honest. But the microwave will the heat the container to a certain degree, just not so much. And the heat required to heat a metal saucepan is fairly low compared to the liquid contents (factor of 10 by weight - water has a huge specific heat capacity compared to most other things, especially heavyish metals).

Yes but if we're comparing like for like, we have to assume we are heating a ceramic bowl on the hob.

[rex008]

Would it not crack?

Definitely less efficient in that case. Unless you regularly lick soup off your hob.

[RED-DOG]

Would it not crack?

Definitely less efficient in that case. Unless you regularly lick soup off your hob.

It probably would crack, but for the sake of argument we have to assume it wouldn't.

We're already routing exhaust gasses through a microwave for Christ's sake.

[Laxie]

Apologies for the lack of weather report, but I can 'splain...I've been in shopping hell today.  Eight fun filled hours of prom dress shopping with a 15 year old.  Good thing I love her to bits or we'd have serious issues!  Ball Gown Heaven tomorrow apparently.  That's actually the name of the shop.  Heaven and hell and in one building.  But first we've a tour of the Space Centre to get through, which will hopefully be pretty cool. 

Anyway.....

After a half decent start to the day, the rest of today was meant to piss out of the heavens.  Pretty sure it did too, but was missed due to to said shopping.

Tomorrow is supposed to be grass cutting weather, so get it done quick before Mother Nature changes her moody mind.

[RED-DOG]

Apologies for the lack of weather report, but I can 'splain...I've been in shopping hell today.  Eight fun filled hours of prom dress shopping with a 15 year old.  Good thing I love her to bits or we'd have serious issues!  Ball Gown Heaven tomorrow apparently.  That's actually the name of the shop.  Heaven and hell and in one building.  But first we've a tour of the Space Centre to get through, which will hopefully be pretty cool. 

Anyway.....

After a half decent start to the day, the rest of today was meant to piss out of the heavens.  Pretty sure it did too, but was missed due to to said shopping.

Tomorrow is supposed to be grass cutting weather, so get it done quick before Mother Nature changes her moody mind.

Can't cut the grass tomorrow, I have to be elsewhere.

I did a terrible mis-read of your post, but I can't say what it was because said 15 year old might be reading.

[Laxie]

Apologies for the lack of weather report, but I can 'splain...I've been in shopping hell today.  Eight fun filled hours of prom dress shopping with a 15 year old.  Good thing I love her to bits or we'd have serious issues!  Ball Gown Heaven tomorrow apparently.  That's actually the name of the shop.  Heaven and hell and in one building.  But first we've a tour of the Space Centre to get through, which will hopefully be pretty cool. 

Anyway.....

After a half decent start to the day, the rest of today was meant to piss out of the heavens.  Pretty sure it did too, but was missed due to to said shopping.

Tomorrow is supposed to be grass cutting weather, so get it done quick before Mother Nature changes her moody mind.

Can't cut the grass tomorrow, I have to be elsewhere.

I did a terrible mis-read of your post, but I can't say what it was because said 15 year old might be reading.

   Whisper it to me in a PM and it'll be our secret. 

Some day I'll actually get 'round to calling to yours.  Once I know the way, I might even help cut the lawn.  We're safe once it's not an electric mower.  I've a bad habit of running over their cords.

[pokerfan]

I have the choice of spending the next two hours either,




Cutting the grass

Click to see full-size image.

Or riding my bike.

Click to see full-size image.

What to do what to do......

Knock one of these up Ldo

[RED-DOG]

Lolz! That's excellent.

[Karabiner]

One that could be drawn by a small dog would be perfect.

[Woodsey]

lol u don't actually take the dog on the bike in that bag do you?

[RED-DOG]

lol u don't actually take the dog on the bike in that bag do you?

Yes, sometimes. She loves it. If I lean the bike over she jumps in herself.

[pokerfan]

One that could be drawn by a small dog would be perfect.

Ha, the Internet is awesome.

[Rod Paradise]

Fuck me, it's raining again.

Old bloke outside post office just now.

Even Gene Kelly would be fucked off by now.

Old guy at bus stop in Glasgow

[RED-DOG]

Life lesson # 3849

You're outdoors doing some or other man-type job and you need a piece of old rag for wiping your hands. You call to your Mrs. She has a root around and throws you an old T shirt.

The T shirt is too big for your purpose. You want to be able to put it in the pocket of your overalls. Solution, tear it in half. Use one piece now, save the other piece for later.

Under no circumstances should you attempt to tear the T shirt if your Mrs, or any other female is watching.

Real life isn't like the movies. The T shirt wont just rent asunder with a satisfying Rrrrippp! What will happen is the veins in your neck will stand out like the strings on a double bass. Your eyes will start to bulge from your head, several of your teeth will shatter,  but the T shirt wont tear. It will just cut ever deeper into your cramped, claw-like fingers.

If you continue to strain, there is a very real danger that you will fart loudly enough to wake someone's baby and you might even crap just a little bit. The chances of this happening are directly proportional to the quality and quantity of the females watching.

The hotter the chicks, the more likely you are to shit yourself.

I know. I was that soldier.