How Is Steam Quantity Converted to Water Volume?

[Waqas]

Hi there,
Is there any method to calculate the amount of steam condensed to form water? Let's assume 1000 lbs of superheated steam at 400⁰C condensed to water at 45⁰C. What will be the amount of water? I have calculated it through specific volume but it returns with a very minimum value.

 

[BvU]

Hello Waqas,

1000 lbs IS an amount of H2O. So 1000 lbs of steam (H2O in vapor phase) will condense to 1000 lbs of water (H2O in liquid phase).

 

[russ_watters]

...as long as the pressure in the condenser is over something like half an atm...or there is something else critical we aren't being told...

 

[Waqas]

Hello Waqas,

1000 lbs IS an amount of H2O. So 1000 lbs of steam (H2O in vapor phase) will condense to 1000 lbs of water (H2O in liquid phase).

Thanks for the reply but may be I couldn't state my problem clearly enough. I will try again. In my case, we are inserting 1000 lb/hr steam in a fractionating column. I need to calculate the water produced. Will it return the same flow?

 

[BvU]

Yes. 1000 lbs of steam will condense to 1000 lbs of water

 

[rwilson7567]

Can you relate this to time? If we release 100 lbs of steam for 1 minute; how much water does that condense to?

 

[berkeman]

Can you relate this to time? If we release 100 lbs of steam for 1 minute; how much water does that condense to?

Welcome to PF.

You mention time, but then "how much". Which is it that you want to understand better. As for how much, that's already been answered (you can convert the weight of the water to the volume of water if you want). As for the time, that would depend on how exactly you were condensing it, no?

 

[rwilson7567]

Then I would need to ask if we use a 2-1/2 inch pipe, at 100 lbs of steam pressure, what is the weight of the water moving through the pipe in 1 minute? Then I can convert to volume.

 

[rwilson7567]

Our application is that we are blowing down a boiler 3 times a day for 1 minute in total. We are building a blow down tank and have to determine how large it will have to be to store condensed water for a month before it is pumped.

 

[anorlunda]

You're getting close to an answerable question. How long is the 2.5 inch pipe? Is there a nozzle on the end? Is the boiler at atmospheric pressure?

Is the 100 PSI steam saturated?
If yes, steam quality or percent moisture in the steam?
If no, then it is superheated; what is the temperature?

 

[rwilson7567]

Steam temp is 230 degrees.
Pipe is 50 ft long; no nozzle.
Don't know steam quality or MC of steam.
boiler is at atmospheric pressure

 

[sysprog]

I think that the question is not well-formed.

 

[anorlunda]

ping @jrmichler and @Chestermiller

 

[jrmichler]

Let's try to answer this. Summarizing the information so far:

Post #6: 100 lbs of steam is released in 1 minute, how much liquid water is that?

Post #8: 100 PSI steam in a 2.5" pipe, what is weight of water?

Post #9: Blowing down boiler 3 times per day for 1 minute total. How much water in 1 month?

Post #11: Steam at 230 deg. Pipe 50 feet long. Boiler at 0 PSIG.

If I take these questions literally, the answers would be as follows:
Post #6: 100 lbs of steam is 100 lbs of water if all of the steam is condensed.

Post #8: It's all steam, so no water. Zero pounds of water.

Post #9: Is that 3 blow downs at 20 seconds each? Or 3 at 1 minute each? No information on boiler pressure, pipe size, pipe length, pipe restrictions, pressure at discharge, or what is blown down. Does boiler blow down release water or steam? At what temperature and pressure? Not possible to answer.

Post #11: Is steam temperature deg F or deg C? What is pressure at pipe discharge? If it discharges to atmosphere, then flow is zero because boiler is at same pressure. If it discharges to a lower pressure, how are you getting the lower pressure? And what is the discharge pressure?

We need the following in order to help you:
1) A sketch of the system. Show the boiler, piping, and what the discharge pipe is connected to.

2) Pressure and temperature at boiler and in blow down tank.

3) Tell us something about the system. For instance, how much water is in the boiler? Anything that will help us to understand what you are doing.

4) Then tell us exactly what you need to know. Is this a complete and correct description of what you need to know?

We are building a blow down tank and have to determine how large it will have to be to store condensed water for a month before it is pumped.

Please note that every item on my list must be answered before I will respond. You can make a pencil sketch, scan or photograph it to a JPG file, then attach to your response by Attach files > Insert > Full image.

 

[Lnewqban]

Hi there,
Is there any method to calculate the amount of steam condensed to form water? Let's assume 1000 lbs of superheated steam at 400⁰C condensed to water at 45⁰C. What will be the amount of water? I have calculated it through specific volume but it returns with a very minimum value.

Welcome, Waqas!
Please, see:
https://www.spiraxsarco.com/learn-a...-recovery/introduction-to-condensate-recovery

 

[BvU]

Then I would need to ask if we use a 2-1/2 inch pipe, at 100 lbs of steam pressure, what is the weight of the water moving through the pipe in 1 minute? Then I can convert to volume.

Hello @rwilson7567 ,

$\qquad$!​

You continue a four year old thread to ask some vaguely related question. Not a good idea.

Furthermore, I am worried considerably about 100 lbs appearing as a pressure in the post above and as an amount of steam in another:

If we release 100 lbs of steam for 1 minute

(and by now I guess you don't mean 100 lbs at all -- probably an unknown amount of 689476 Pascal ( -- in case that looks strange: the pascal is the unit of pressure in civilised countries, but 7 Bara --- or is it 7 Barg ? is an acceptable alternate ) steam of unknown quality (most likely saturated).

Fortunately you are in good hands now (a lot of them!), so I'll switch to listening mode

$\$

Welcome, Waqas!
Please, see:
https://www.spiraxsarco.com/learn-a...-recovery/introduction-to-condensate-recovery

Well, this guy wasn't seen for four and a half years, but I'm sure he'll be grateful for a (second) welcome

$\$