Math formula question I need help with please,

gerry gill

Is there a formula to turn 'pounds of steam' into 'edr'? Keep in mind i went to Chicago public school which means you'll have to break it down into 5th grade level for me. ;)

MikeyB

Steam/EDR

Gerry I found this older post from Brad White, hope it helps



"At sea level, atmospheric pressure (zero on the gauge), there are 970.3 BTUs per pound of steam at saturation. At the same saturation conditions: At one pound, that drops to about 968 BTUs per lb. At two pounds, that drops to about 966 BTUs per lb. At five pounds, that drops to about 960 BTUs per lb. For low pressure radiator heating, this 960 number is often used for rough purposes, just a wee bit conservative. It also corresponds to the "four square feet of EDR per pound of steam" rule of thumb. No real conversion, just tables. Now, if you have a load of say, 10,000 BTUs per hour, you would need a steam radiator of about 42 EDR and this would require about 10.5 lbs. per hour to serve it".

gerry gill

hmmm, thats confusing.

I thought edr divided by 4 was pounds of condensate not steam..what i'm doing is i've been studying old sizing charts for pipes, and while most are in edr, warren websters are in pounds of steam..for example a such and such size riser can deliver X amount of pounds of steam for 300 feet at a certain pressure drop..i live in an edr world, not a pounds of steam world, so i'm trying to figure out how to cross reference the two.

MikeyB

Formula

I see what your talking about Gerry, i think there might be more than one conversion you would have to do to get to EDR, I found a chart that has conversion factors on it, if you know the LBS of steam/hr multiply that by .029 to obtain HP, then take HP and multiply that by 140 to obtain sq.ft EDR steam, see atatched table, not sure if this is what your looking for?

Dave in QCA

Guessing here....

Gerry,  I'm stepping out side of my expertise and I do not have any tables or graphs in front of me.  Be correct me if I am wrong here...   Would it not take a pound of steam to make a pound of condensate?  The material being measured is water.  Steam  being the vapor state and condensate being liquid state.  When water changes from one state to the other, it is neither created nor destroyed, just in a different form, and therefore, the mass (weight)  would be the same and obviously, the volume would not.

gerry gill

Thanks MikeyB

Thats a fantastic chart, thank you..i'll have to play around with that and with what Dave said below and see if it all works out..great find on that chart-thanks again.

gerry gill

Thanks Dave-

What you say sounds right to me..i hadn't thought about it that way..i'll have to play around with MikeyB's chart and see if it works out..its that Chicago schooling you know..follows me around like a bad case of herpes..if it wasn't for the navy and Dan Holohan books i wouldn't know anything..lol..Thanks Dave.

STEAM DOCTOR

page 46 in lost art

pounds times 4= edr

gerry gill

Thanks bn

so the answer was sitting on my desk? ..how pathetic..i should probably re-read that book! its been awhile.

MikeyB

EDR

Gerry, i came across some more- EDR = 0.25 pounds of steam,  from Lessons learned in a Boiler Room (great book) & Pounds of steam per hour  X 1000=BTU/HR, & Pounds of steam/hr X 4 = Sq foot output taken from  Linhardts Field Guide (another great book)

gerry gill

Thanks MikeyB-

I have to go find my Linhardt book now..i got it somewhere.. thanks