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Posted: 5/27/2009 7:40:33 AM EDT


Is it as simple as 8.3#?
Link Posted: 5/27/2009 7:42:29 AM EDT
Container size?

Thinking PSI?

I don't know, just waiting for Keith_J
Link Posted: 5/27/2009 7:42:59 AM EDT
yes it is that easy.

Link Posted: 5/27/2009 7:43:22 AM EDT
Yup.
Link Posted: 5/27/2009 7:43:30 AM EDT
8.34 pounds
Link Posted: 5/27/2009 7:43:35 AM EDT
Conservation of mass, since converting the water to steam is neither a fision or fusion reaction, thus you will get 8.345404487293294 pounds or ~8.35 pounds of steam.
Link Posted: 5/27/2009 7:44:39 AM EDT
[Last Edit: 5/27/2009 7:45:04 AM EDT by TacticalMOLONLABE]
Eight ^^^^
Link Posted: 5/27/2009 7:45:21 AM EDT
Why would any weight be lost or gained?



Link Posted: 5/27/2009 7:45:23 AM EDT
How can 1 gallon (6lbs) of gasoline produce 22lbs of Co2?
Link Posted: 5/27/2009 7:45:52 AM EDT
How could it produce more than a gallon of water weighs which is 8.345404487293294 lbs?.

ETA, I really have no idea on the steam, but my guess is above.
Link Posted: 5/27/2009 7:46:57 AM EDT
Originally Posted By ragedracer1977:
How can 1 gallon (6lbs) of gasoline produce 22lbs of Co2?


The carbon in gasoline combines with atmospheric O2.
Link Posted: 5/27/2009 7:47:00 AM EDT
Originally Posted By ragedracer1977:
How can 1 gallon (6lbs) of gasoline produce 22lbs of Co2?


The combustion product is heavier. You are adding 2 oxygen atoms to the carbon in the gas
Link Posted: 5/27/2009 7:48:25 AM EDT
Conservation of Mass...
Link Posted: 5/27/2009 7:48:46 AM EDT
Originally Posted By molotov357:
8.34 pounds


this
Link Posted: 5/27/2009 7:50:07 AM EDT
Originally Posted By ragedracer1977:
How can 1 gallon (6lbs) of gasoline produce 22lbs of Co2?


Because it is a combustion process, which involve other oxidizer specifically oxygen or air, which introduce extra mass. You can heat a gallon of gasoline in its container (assuming it is strong enough to hold the pressure) to whatever temperature you wanted, if there are no air or other oxidizer to produce combustion, all you get is 6 pounds worth of super heated gasoline vapor.
Link Posted: 5/27/2009 7:50:22 AM EDT
[Last Edit: 5/27/2009 7:51:08 AM EDT by Keith_J]
Saturated? Need to know temperature OR pressure to determine volume.

Superheated? Need to know both temperature AND pressure ti determine volume.


Mass doesn't change.
Link Posted: 5/27/2009 7:52:35 AM EDT
Isn't the mass of steam a far more useful measure than its weight? Isn't the "weight" of the steam variable with temperature and pressure? Did high school science fail me on this point?
Link Posted: 5/27/2009 7:58:46 AM EDT
[Last Edit: 5/27/2009 8:04:45 AM EDT by VBC]
Originally Posted By krpind:


Is it as simple as 8.3#?


If the water is cold.

If the water is hot (like 180 degrees F), it would be 8.1 lbs.


Because liquid water changes density with temperature.
Link Posted: 5/27/2009 8:00:44 AM EDT
Are you talking about weight or pressure?

The same amount of water in liquid or steam form would weigh the same.
Link Posted: 5/27/2009 8:00:56 AM EDT
Originally Posted By Keith_J:
Saturated? Need to know temperature OR pressure to determine volume.

Superheated? Need to know both temperature AND pressure ti determine volume.


Mass doesn't change.


The story is an engineer working on a project here in town came in to ask me this. I told him, it would be 8.3#.

He wasn't sure that was correct.

He has boilers and is trying to drive steam hammers and it isn't working properly. He is consuming water to the tune of 150Kgallons/day.

Come to find out he is only getting 212 degree water, which isn't even steam anyway. I told him to increase the BTUs and raise the water temp to 250 to 275. That should cut down on his water consumption and make the hammers work.

I guess.....not really what we do anyway.



Link Posted: 5/27/2009 8:04:45 AM EDT
Link Posted: 5/27/2009 8:06:57 AM EDT
Originally Posted By krpind:
Originally Posted By Keith_J:
Saturated? Need to know temperature OR pressure to determine volume.

Superheated? Need to know both temperature AND pressure ti determine volume.


Mass doesn't change.


The story is an engineer working on a project here in town came in to ask me this. I told him, it would be 8.3#.

He wasn't sure that was correct.

He has boilers and is trying to drive steam hammers and it isn't working properly. He is consuming water to the tune of 150Kgallons/day.

Come to find out he is only getting 212 degree water, which isn't even steam anyway. I told him to increase the BTUs and raise the water temp to 250 to 275. That should cut down on his water consumption and make the hammers work.

I guess.....not really what we do anyway.






8.3 lbs isn't correct at 212 degree water. It's more like 8.1 lbs.

Slight difference, but at 150Kgals it becomes substantial.

Link Posted: 5/27/2009 8:08:00 AM EDT

Originally Posted By krpind:
Originally Posted By Keith_J:
Saturated? Need to know temperature OR pressure to determine volume.

Superheated? Need to know both temperature AND pressure ti determine volume.


Mass doesn't change.


The story is an engineer working on a project here in town came in to ask me this. I told him, it would be 8.3#.

He wasn't sure that was correct.

He has boilers and is trying to drive steam hammers and it isn't working properly. He is consuming water to the tune of 150Kgallons/day.

Come to find out he is only getting 212 degree water, which isn't even steam anyway. I told him to increase the BTUs and raise the water temp to 250 to 275. That should cut down on his water consumption and make the hammers work.

I guess.....not really what we do anyway.




He isn't an engineer. Or he might be from TU or one of them diploma mills .

Yes, turn up the BTUs because it is ENERGY which is driving the hammers. Energy communicated from the flame to the piston by steam. Unless the boiler and steam hammers are at 15,000 feet of altitude, there is no pressure in 212F water.
Link Posted: 5/27/2009 8:09:15 AM EDT
[Last Edit: 5/27/2009 8:12:01 AM EDT by VBC]
Originally Posted By Zhukov:

Originally Posted By VBC:
Originally Posted By krpind:


Is it as simple as 8.3#?

If the water is cold.

If the water is hot (like 180 degrees F), it could be 8.1 lbs.

Because liquid water changes density with temperature.

Density != mass. The VOLUME will change with temperature, but not the mass. You left off one important aspect of density, and that is that it's given in mass PER volume, ie. mg/cm^3.



Read the OP again. He specified 1 GALLON of water. The volume is constant in his problem.
Desnity changes with temp. If volume is held constant, mass will change.

I didn't leave off anything. You misunderstood the problem.
Link Posted: 5/27/2009 8:11:01 AM EDT
Originally Posted By VBC:
Originally Posted By krpind:
Originally Posted By Keith_J:
Saturated? Need to know temperature OR pressure to determine volume.

Superheated? Need to know both temperature AND pressure ti determine volume.


Mass doesn't change.


The story is an engineer working on a project here in town came in to ask me this. I told him, it would be 8.3#.

He wasn't sure that was correct.

He has boilers and is trying to drive steam hammers and it isn't working properly. He is consuming water to the tune of 150Kgallons/day.

Come to find out he is only getting 212 degree water, which isn't even steam anyway. I told him to increase the BTUs and raise the water temp to 250 to 275. That should cut down on his water consumption and make the hammers work.

I guess.....not really what we do anyway.






8.3 lbs isn't correct at 212 degree water. It's more like 8.1 lbs.

Slight difference, but at 150Kgals it becomes substantial.



He says it is less as well.

I don't see how......I'm more than willing to be proven wrong here, it just seems that if I convert a gallon of water to steam [no matter what the temp or pressure is] it is always going to weigh appox 8.3...lbs

Link Posted: 5/27/2009 8:12:45 AM EDT
Originally Posted By crurifragium:
Originally Posted By ragedracer1977:
How can 1 gallon (6lbs) of gasoline produce 22lbs of Co2?


The carbon in gasoline combines with atmospheric O2.


Woa! That's astounding. We need to do something about that! I suggest we charge everyone according to how much carbon they emit. Failing to do so could be catastrophic.
Link Posted: 5/27/2009 8:13:29 AM EDT
Link Posted: 5/27/2009 8:15:45 AM EDT
African water or European water?
Link Posted: 5/27/2009 8:15:47 AM EDT
[Last Edit: 5/27/2009 8:18:42 AM EDT by VBC]
Originally Posted By krpind:
Originally Posted By VBC:
Originally Posted By krpind:
Originally Posted By Keith_J:
Saturated? Need to know temperature OR pressure to determine volume.

Superheated? Need to know both temperature AND pressure ti determine volume.


Mass doesn't change.


The story is an engineer working on a project here in town came in to ask me this. I told him, it would be 8.3#.

He wasn't sure that was correct.

He has boilers and is trying to drive steam hammers and it isn't working properly. He is consuming water to the tune of 150Kgallons/day.

Come to find out he is only getting 212 degree water, which isn't even steam anyway. I told him to increase the BTUs and raise the water temp to 250 to 275. That should cut down on his water consumption and make the hammers work.

I guess.....not really what we do anyway.






8.3 lbs isn't correct at 212 degree water. It's more like 8.1 lbs.

Slight difference, but at 150Kgals it becomes substantial.



He says it is less as well.

I don't see how......I'm more than willing to be proven wrong here, it just seems that if I convert a gallon of water to steam [no matter what the temp or pressure is] it is always going to weigh appox 8.3...lbs



It depends at what temp. the liquid water is when it enters your thermodynamic cycle.

The relationship between density of water vs. temperature is here:

http://hypertextbook.com/facts/2007/AllenMa.shtml

If you start out with hot water (200 degree water), it's density if only going to be about 8.1 lbs/gallon, due to expansion. Water at 40 degrees is about 8.3 lbs/gallon.





Link Posted: 5/27/2009 8:17:01 AM EDT
[Last Edit: 5/27/2009 8:18:58 AM EDT by molotov357]
Originally Posted By VBC:
Originally Posted By krpind:
Originally Posted By Keith_J:
Saturated? Need to know temperature OR pressure to determine volume.

Superheated? Need to know both temperature AND pressure ti determine volume.


Mass doesn't change.


The story is an engineer working on a project here in town came in to ask me this. I told him, it would be 8.3#.

He wasn't sure that was correct.

He has boilers and is trying to drive steam hammers and it isn't working properly. He is consuming water to the tune of 150Kgallons/day.

Come to find out he is only getting 212 degree water, which isn't even steam anyway. I told him to increase the BTUs and raise the water temp to 250 to 275. That should cut down on his water consumption and make the hammers work.

I guess.....not really what we do anyway.






8.3 lbs isn't correct at 212 degree water. It's more like 8.1 lbs.

Slight difference, but at 150Kgals it becomes substantial.



So lets say you have a hollow iron sphere with 1 gallon of water inside.

At room temperature this sphere is placed on a scale and reads 28.34 pounds (assume the sphere is 20 pounds)

A torch is used to heat the sphere to 1000 degrees to ensure the water inside becomes steam. Would the sphere not still read 28.34 pounds?

The mass has not changed. Neither has the earths gravitational effect changed. I don't see how the weight could vary.
Link Posted: 5/27/2009 8:17:46 AM EDT


I'll be damned.

Link Posted: 5/27/2009 8:21:51 AM EDT
[Last Edit: 5/27/2009 8:24:28 AM EDT by VBC]
Originally Posted By molotov357:
Originally Posted By VBC:
Originally Posted By krpind:
Originally Posted By Keith_J:
Saturated? Need to know temperature OR pressure to determine volume.

Superheated? Need to know both temperature AND pressure ti determine volume.


Mass doesn't change.


The story is an engineer working on a project here in town came in to ask me this. I told him, it would be 8.3#.

He wasn't sure that was correct.

He has boilers and is trying to drive steam hammers and it isn't working properly. He is consuming water to the tune of 150Kgallons/day.

Come to find out he is only getting 212 degree water, which isn't even steam anyway. I told him to increase the BTUs and raise the water temp to 250 to 275. That should cut down on his water consumption and make the hammers work.

I guess.....not really what we do anyway.






8.3 lbs isn't correct at 212 degree water. It's more like 8.1 lbs.

Slight difference, but at 150Kgals it becomes substantial.



So lets say you have a hollow iron sphere with 1 gallon of water inside.

At room temperature this sphere is placed on a scale and reads 28.34 pounds (assume the sphere is 20 pounds)

A torch is used to heat the sphere to 1000 degrees to ensure the water inside becomes steam. Would the sphere not still read 28.34 pounds?

The mass has not changed. Neither has the earths gravitational effect changed. I don't see how the weight could vary.



That would be true under those conditions. But weigh the sphere full of water at 200 degrees in the beginning, then do your problem.. You will begin with a different weight, which will produce that weight in steam.

His problem is assuming that you have 1 gallon of water in the beginning. Therefore, how much that 1 gallon weighs, will depend on the density of the water, which depends on its temperature.

If he started out with 1 gallon at 40 degrees, he would produce 8.3 lbs of steam.

If he started out with 1 gallon at 200 degrees, he would produce 8.0 lbs of steam.





Link Posted: 5/27/2009 8:27:15 AM EDT
Link Posted: 5/27/2009 8:27:26 AM EDT

Originally Posted By photokirk:
African water or European water?

Are suggesting that water migrates?!?
Link Posted: 5/27/2009 8:33:04 AM EDT
[Last Edit: 5/27/2009 8:34:09 AM EDT by brickeyee]
Originally Posted By VBC:
Originally Posted By molotov357:
Originally Posted By VBC:
Originally Posted By krpind:
Originally Posted By Keith_J:
Saturated? Need to know temperature OR pressure to determine volume.

Superheated? Need to know both temperature AND pressure ti determine volume.


Mass doesn't change.


The story is an engineer working on a project here in town came in to ask me this. I told him, it would be 8.3#.

He wasn't sure that was correct.

He has boilers and is trying to drive steam hammers and it isn't working properly. He is consuming water to the tune of 150Kgallons/day.

Come to find out he is only getting 212 degree water, which isn't even steam anyway. I told him to increase the BTUs and raise the water temp to 250 to 275. That should cut down on his water consumption and make the hammers work.

I guess.....not really what we do anyway.






8.3 lbs isn't correct at 212 degree water. It's more like 8.1 lbs.

Slight difference, but at 150Kgals it becomes substantial.



So lets say you have a hollow iron sphere with 1 gallon of water inside.

At room temperature this sphere is placed on a scale and reads 28.34 pounds (assume the sphere is 20 pounds)

A torch is used to heat the sphere to 1000 degrees to ensure the water inside becomes steam. Would the sphere not still read 28.34 pounds?

The mass has not changed. Neither has the earths gravitational effect changed. I don't see how the weight could vary.



That would be true under those conditions. But weigh the sphere full of water at 200 degrees in the beginning, then do your problem.. You will begin with a different weight, which will produce that weight in steam.

His problem is assuming that you have 1 gallon of water in the beginning. Therefore, how much that 1 gallon weighs, will depend on the density of the water, which depends on its temperature.

If he started out with 1 gallon at 40 degrees, he would produce 8.3 lbs of steam.

If he started out with 1 gallon at 200 degrees, he would produce 8.0 lbs of steam.







He is most likely starting with about 40 F water, possibly form a municipal supply or a storage tank.

It sounds like he is boiling the water at atmospheric pressure (or very slightly above) producing a very wet low energy steam.
Increase the operating pressure and the amount of water used will significantly decrease and the hammers will actually work.

Tell him to look up 'superheat.'
That is how steam is used to perform work (like turning turbines or driving hammers).


The only thing wet steam is useful for is moving heat from point A to point B, and large systems still super heat it to move more heat.
Link Posted: 5/27/2009 8:33:07 AM EDT
[Last Edit: 5/27/2009 8:34:26 AM EDT by VBC]
Originally Posted By Zhukov:

Originally Posted By VBC:

Read the OP again. He specified 1 GALLON of water. The volume is constant in his problem.
Desnity changes with temp. If volume is held constant, mass will change.

I didn't leave off anything. You misunderstood the problem.

You're right. He specified volume. I'm a bonehead.


Welcome to the club. Every once and a while I get lucky.
Link Posted: 5/27/2009 8:36:12 AM EDT
Originally Posted By brickeyee:
Originally Posted By VBC:
Originally Posted By molotov357:
Originally Posted By VBC:
Originally Posted By krpind:
Originally Posted By Keith_J:
Saturated? Need to know temperature OR pressure to determine volume.

Superheated? Need to know both temperature AND pressure ti determine volume.


Mass doesn't change.


The story is an engineer working on a project here in town came in to ask me this. I told him, it would be 8.3#.

He wasn't sure that was correct.

He has boilers and is trying to drive steam hammers and it isn't working properly. He is consuming water to the tune of 150Kgallons/day.

Come to find out he is only getting 212 degree water, which isn't even steam anyway. I told him to increase the BTUs and raise the water temp to 250 to 275. That should cut down on his water consumption and make the hammers work.

I guess.....not really what we do anyway.






8.3 lbs isn't correct at 212 degree water. It's more like 8.1 lbs.

Slight difference, but at 150Kgals it becomes substantial.



So lets say you have a hollow iron sphere with 1 gallon of water inside.

At room temperature this sphere is placed on a scale and reads 28.34 pounds (assume the sphere is 20 pounds)

A torch is used to heat the sphere to 1000 degrees to ensure the water inside becomes steam. Would the sphere not still read 28.34 pounds?

The mass has not changed. Neither has the earths gravitational effect changed. I don't see how the weight could vary.



That would be true under those conditions. But weigh the sphere full of water at 200 degrees in the beginning, then do your problem.. You will begin with a different weight, which will produce that weight in steam.

His problem is assuming that you have 1 gallon of water in the beginning. Therefore, how much that 1 gallon weighs, will depend on the density of the water, which depends on its temperature.

If he started out with 1 gallon at 40 degrees, he would produce 8.3 lbs of steam.

If he started out with 1 gallon at 200 degrees, he would produce 8.0 lbs of steam.







He is most likely starting with about 40 F water, possibly form a municipal supply or a storage tank.

It sounds like he is boiling the water at atmospheric pressure (or very slightly above) producing a very wet low energy steam.
Increase the operating pressure and the amount of water used will significantly decrease and the hammers will actually work.

Tell him to look up 'superheat.'
That is how steam is used to perform work (like turning turbines or driving hammers).


The only thing wet steam is useful for is moving heat from point A to point B, and large systems still super heat it to move more heat.



Now we have a real mechanical engineer on board. This sounds legit.


Link Posted: 5/27/2009 8:37:05 AM EDT
Originally Posted By VBC:
Originally Posted By krpind:


Is it as simple as 8.3#?


If the water is cold.

If the water is hot (like 180 degrees F), it would be 8.1 lbs.


Because liquid water changes density with temperature.


Actually if the water was cold, you would get less mass per unit of volume. Water loses density as it approaches the freezing point. That's why ice floats.

Link Posted: 5/27/2009 8:37:15 AM EDT
Originally Posted By leungken:
Conservation of mass...


...does not apply, since a pound is a scalar quantity.

Put that in your pipe and chew on it for a while.
Link Posted: 5/27/2009 8:41:21 AM EDT
Originally Posted By sigp226:
Originally Posted By VBC:
Originally Posted By krpind:


Is it as simple as 8.3#?


If the water is cold.

If the water is hot (like 180 degrees F), it would be 8.1 lbs.


Because liquid water changes density with temperature.


Actually if the water was cold on the verge of freezing, you would get less mass per unit of volume. Water loses density as it approaches the freezing point. That's why ice floats.



IIRC, it keeps getting denser down to about 35 degrees F, then it gets slightly less dense just before it freezes.

For as ubiquitous as it is, water is a very unique compound with unique properties. The universal solvent.
Link Posted: 5/27/2009 8:43:30 AM EDT
I'm pretty sure water vapor has little or no weight.

It does have mass though
Link Posted: 5/27/2009 8:46:32 AM EDT
Originally Posted By VBC:
Originally Posted By sigp226:
Originally Posted By VBC:
Originally Posted By krpind:


Is it as simple as 8.3#?


If the water is cold.

If the water is hot (like 180 degrees F), it would be 8.1 lbs.


Because liquid water changes density with temperature.


Actually if the water was cold on the verge of freezing, you would get less mass per unit of volume. Water loses density as it approaches the freezing point. That's why ice floats.



IIRC, it keeps getting denser down to about 35 degrees F, then it gets slightly less dense just before it freezes.

For as ubiquitous as it is, water is a very unique compound with unique properties. The universal solvent.


I remember a chenistry experiment with ice water and a graduated cylinder. We had to measure the temperature of the water at different depths and 35 degrees Fahrenheit sounds familiar.

Link Posted: 5/27/2009 9:04:47 PM EDT
Originally Posted By krpind:


Is it as simple as 8.3#?


yes.
Link Posted: 5/27/2009 10:00:22 PM EDT
Originally Posted By sigp226:
Originally Posted By VBC:
Originally Posted By krpind:


Is it as simple as 8.3#?


If the water is cold.

If the water is hot (like 180 degrees F), it would be 8.1 lbs.


Because liquid water changes density with temperature.


Actually if the water was cold, you would get less mass per unit of volume. Water loses density as it approaches the freezing point. That's why ice floats.



NO!

Ice floats because water expands (into a crystalline structure) as it changes from a liquid phase to a solid phase. Pretty much no other known substance decreases in density when changing phase from liquid to solid.

And as far as the density of liquid water:
Water is most dense at 4 degrees C, slightly less dense at or near freezing, and less dense as it gets heavier.

Not an engineer (yet)
Link Posted: 5/27/2009 10:01:23 PM EDT
Pound of feathers or pound of bricks?
Link Posted: 5/27/2009 10:02:01 PM EDT
Originally Posted By ragedracer1977:
How can 1 gallon (6lbs) of gasoline produce 22lbs of Co2?


Because Al Gore says so..
Link Posted: 5/28/2009 12:26:50 AM EDT
African or European steam?
Link Posted: 5/28/2009 12:40:27 AM EDT
Which weighs more, a pound of coal or a pound of feathers?
Link Posted: 5/28/2009 2:50:26 AM EDT
[Last Edit: 5/28/2009 2:51:16 AM EDT by cosmo05]

[/quote]

So lets say you have a hollow iron sphere with 1 gallon of water inside.

At room temperature this sphere is placed on a scale and reads 28.34 pounds (assume the sphere is 20 pounds)

A torch is used to heat the sphere to 1000 degrees to ensure the water inside becomes steam. Would the sphere not still read 28.34 pounds?

The mass has not changed. Neither has the earths gravitational effect changed. I don't see how the weight could vary.[/quote]


That better be one strong ass sphere, that gallon of water will turn into 1600 gallons of steam with nowhere to go!

Link Posted: 5/28/2009 3:00:07 AM EDT
What weighs more a ton of feathers, or a ton of bricks?
Link Posted: 5/28/2009 3:05:31 AM EDT
[Last Edit: 5/28/2009 3:08:37 AM EDT by Dr_Dickie]
Mass is conserved; HOWEVER, weight is not mass.
The increase in bouncy of the steam will make it weight less (perhaps even negative––and pounds is NOT a measure of mass, but of weight––the English units of mass are slugs). It really only makes sense if you use pounds as mass. Then there is no change due to phase change.
If you want volume, the rule of thumb is 1000x volume increase in going to gas phase (at room temperature). To get the volume better, you need mass and temperature and pressure.
As written, the question is nonsensical.
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