How many gallons of water can I heat

Mike T., Swampeast MO

Sounds like a school problem...

First, water at 212° is NOT steam--it is water at 212°!

Second, it's easiest to work in pounds instead of gallons because a BTU is the amount of heat required to raise one pound of water one degree Fahrenheit.

So, to heat one pound of water to 212° you need (212-55) = 157 BTUs.

Now to turn that one pound of water to one pound of steam you must add another 970.4 BTUs (approximately). This is the latent heat required to evaporate the water into steam.

So, each pound of water at 55° needs approximately 970.4 + 157 = 1,127.4 BTUs to become one pound of steam.

You have 1,000,000 BTUs to work with so 1,000,000 / 1,127.4 = 887 pounds.

A gallon of water at 55° weighs about 8.33 pounds. 887 / 8.33 = 106.5 gallons of water at 55° evaporated into steam with 1,000,000 BTUs.

Note that these are not truly exact numbers and that this applies to standard (sea level) atmospheric pressure. Time is immaterial to this answer as it's assuming perfect heat transfer with zero loss.

Steam Bunny

Does anyone know

How many gallons of water I could heat from 55 to 212 degrees (steam) in 15 minutes with 1,000,000 btu? Do you know where I'd find the formula?

Many thanks.

Lurker_2

math

You can do the math. Here's a rounded version (so I don't need to whip out the calculator)

1 gallon is roughly 8.3 lbs of water. It takes roughly 8.3 * 160 = 1300 BTU to raise 1 gallon of water from 55 degrees to 212 degrees.

To turn that into steam takes another 970 or so BTU per pound, so that's an extra 8000 BTU. So, all in, 9300 BTU per gallon.

1,000,000 BTU / 9300 BTU/gallon = a bit over 100 gallons.

-Michael

bob_50

Bad Question

Im no math guy but i think there is a flaw in your question. You state you have 1,000,000btu but no time. By my cypherin you could heat approx 106.9 gal. of water from 55 to 212 saturated steam with 1,000,000 btu. 212-55=157 157 plus the latent heat 970=1127. 1127*8.3=9354.1 btu per gal. 1,000,000/9354.1=106.9 If you meant 1,000,000 btu/hour then it would be 26.75 gal. in 15 min.