Boiler firing rate

kcopp

Looking to replace a Peerless EC-05 steam boiler.
I measured out the radiation as best I could (some really different CI convectors) and got a EDR number....it seemed low. I want to see what they were using for a firing rate.... boiler has a .50 gph 70W nozzle. Seemed way undersized for the boiler. I asked about the pressure firing rate and it was 1200 psi. Apparently this was an experimental burner. Anyone have an idea what the firing rate on a 1200psi half gallon/ hr is?
They are going to convert to gas so am I'm looking to eliminate the burner.

HVACNUT

Pump pressure is not 1200 psi. 120 psi maybe. 

STEVEusaPA

Depending on the burner, that boiler should be fired on or over 1.5 gph @ 140 psi.
There's almost no reason to underfire a properly sized steam boiler.

But if you have a burner that fires at 1200 psi, I'd like to see it, and I'll come get it off of you.

Are they converting the boiler to gas, or replacing the boiler with gas?

kcopp

1200 psi... not a typo.
It was an experimental burner a few years back. Preheat.
Happy to get pix.
Im sure he would be willing to sell it.
He actually invested money to get this onto the open market but it went bust.
The boiler is shot, back wall toast.
They are going to nat gas. Want a Nat gas unit now.
Big place.

HVACNUT

I don't know how to do the math, but...
.50 nozzle @ 200 PSI is .71 GPH for a 42% increase. 
.50 nozzle @ 300 PSI is .87 GPH for a 74% increase. 
Is it safe to say that a .50 nozzle @ 1200 PSI is a tad over fired for the boiler?
I would like to see this burner. Maybe it needs a really long chamber. 

Steamhead

Is that a "Burner Booster"?

kcopp

I believe so. It was a heck of a set up. Burned super clean he said.

Steamhead

I went to see this when it was first advertised. The principle appeared sound, and probably would have gained traction 30 or so years ago. But at that time, gas was a lot less expensive and still is.

EBEBRATT-Ed

here's the formula:

F1= nozzle flow rate at (100psi)

F2=nozzle flow rate at (1200psi)

P1=100 psi nozzle pressure

P2= 1200 psi new nozzle pressure


F2=F1 x (P2/P1) .5 (exponent)


No math wiz here I use a calculator or count on my fingers LOL

I'll bet a smat guy like @Jamie Hall could whip this out

mattmia2

I have 2 engineering degrees and i'm not sure where .5(exponent) is supposed to go

Is it:

F2=F1 * ((P2/P1)^.5)

note that X^.5=squareroot(X)

EBEBRATT-Ed

@mattmia2
.5
Yes I think so Exponent applies to the P2
P1

They had it written like above with brackets around the P1 & P2

I guess some things you can't do on a keyboard

STEVEusaPA

mattmia2 said:

I have 2 engineering degrees and i'm not sure where .5(exponent) is supposed to go

Is it:

F2=F1 * ((P2/P1)^.5)

note that X^.5=squareroot(X)

Did you pay off both of those degrees or is there some kind of refund available...
Of course I'm teasing you...easy...easy everyone...lol

EBEBRATT-Ed

I found what I was looking for on a Beckett nozzle chart.

Divide new oil pressure (1200) new pressure) by (100 std nozzle pressure=12

Find the square root of 12 (you can google it)=3.46410162

Multiply the square root you found (3.46410162) x nozzle rating @100psi in this case .50gph

3.46410162 x .50 (nozzle size) + a firing rate of 1.73205081 or 1.73 gph


The one I always have stuck in my head for some reason is a 12 gph nozzle @300psi will give you about 20gph

Answer: from Beckett Chart:20.79gph

Answer from calculation: 300/100=3, square root of 3 is 1.74something 1.74 x 12=20.88

EdTheHeaterMan

here is the correct way to write the equation

mattmia2

so it is this:
F2=F1 * ((P2/P1)^.5)
which is this:
F2=F1 * sqrt(P2/P1)

STEVEusaPA

According to the little app I made, I agree with @EBEBRATT-Ed. However when I looked up that formula that @EdTheHeaterMan posted, one of the notes was that it's not as accurate at pressures over 300 psi.

kcopp

Wow! Thanks!

EBEBRATT-Ed

I also tried the formula that @EdTheHeaterMan posted but I don't digest exponents very well

STEVEusaPA

Parentheses, exponents, multiplication & division, addition & subtraction.
P1=100
P2=1200
P2/P1=12
12^.5= 3.46410161514 or the square root of 12
F2=F1 * 3.46410161514
F2= .5 * 3.46410161514
F2= 1.73205080757

STEVEusaPA

mattmia2 said:

so it is this:
F2=F1 * ((P2/P1)^.5)
which is this:
F2=F1 * sqrt(P2/P1)

You don’t need the extra parentheses.

F2=F1 * (P2/P1)^.5
Either way ya need a calculator…

mattmia2

don't need them but it make it more clear when you aren't typesetting it the way you would write it

EBEBRATT-Ed

I like the Beckett formula, much simpler for me at least