Steam Sizing

PeteDH

I am trying to size a steam boiler for a commercial building which has been fed with steam from a plant across the street for years. We need about 400K BTU for the existing heat exhanger and steam fan coils in the building. But we are trying to figure out how many BTU's we need for the water tanks that we have to heat. They hold about 1300 gallons of water and have to maintain 140 degrees all day long. There are 4 tanks supplied with a 2" main steam pipe and 1" lines feeding each tank. There are steam coils inside the tanks which we cannot physically see. We need to figure out how many BTU's or square feet of steam we need to heat the tanks?

JStar

RE

I'm no expert at sizing for this kind of application, but I'll do some math and hopefully somebody chimes in with their advice.



1300 Gallons = 10,842 Pounds of Water

140F Water, if starting at 50F makes a 90F rise.

So you would need 975,780 BTUH.



With a 2" steam supply, you would need 37 PSI steam pressure to maintain that BTUH rating.



Again, don't take this for fact. Want to see what others say about it.

LarryC

Water tank heating and system questions.

TANK QUESTIONS

What is the usage rate of the hot water, if any? 

How fast does it have to recover?

What is the incoming water temperature?

What are the tanks used for? 

Are they open air tanks like dip tanks for cleaning or plating operations?

 

SYSTEM QUESTIONS

Was there some sort of flow meter or recording device showing how much steam or condensate was being used or returned?

What pressure was the power house steam system supplying?

What pressure was the building system using?

Was there a pressure reducing valve?  If so, what size and model number?

What size was the steam supply line?

Any as built drawings you can review?

Any pressure gauges that might give you clues as to what the system pressure was or is?