Can Liquid Water Exist at 120°C?

[maxx_payne]

hello guys
how can i have liquid water at 120 c ?

 

[phyzguy]

The boiling point of water is a function of pressure. At pressures above 1 atm, water will remain liquid at temperatures above 100C. At the bottom of the ocean, there are places where liquid water is 300C or even hotter. Nuclear reactors use liquid water above 500C. Have you ever used a pressure cooker?

 

[maxx_payne]

so how can i increase the pressure of water ??

 

[maxx_payne]

and if i have a system with two small heaters immursed in water and i need the water to be liquid at 120 or 130
if my system only consist of those heaters then i will have steam
and if i use a pump to pump the water to my system it will pump steam ?
so how can i make good design to this system ??

 

[phyzguy]

Well, a pressure cooker works by just sealing a vessel so that the steam can't escape, then the steam itself pressurizes the vessel as you heat it. Or you can use a pump to pressurize the vessel - this is what is done in a nuclear reactor. Whether the pump pumps liquid or gas depends on what the pump is designed to do. Be careful! Pressure cookers can explode if the pressure exceeds what the vessel is capable of withstanding!

 

[maxx_payne]

thanks man but
what will happen if i pump pressurized water to the heaters ?
sure i know the point of explosion so i will use safety valve

 

[phyzguy]

I don't know how to answer your question. What do you mean, "What will happen?" What are you trying to build?

 

[maxx_payne]

i am trying to build a system produces water at 120
i mean by the term what will happen that
whats the effect of the pump on the water reaching the heaters ??

 

[phyzguy]

If all you want is liquid water at 120C, the simplest thing is just to use a pressure cooker arrangement:
http://en.wikipedia.org/wiki/Pressure_cooker
Then no pump is required.

 

[maxx_payne]

so tell me how can i make a system from
1- pump
2- heater

 

[phyzguy]

Sorry, I can't design a system for you. I'm going to bow out. Good luck.

 

[xxChrisxx]

This really depends on WHY you want water at 120C. ie the application. It also depends on what quality you need (the liquid vapour ratio).

 

[jack action]

To have liquid water at 120°C you must pressurized it, you can't get out of it.

Here's a copy of the http://www.engineeringtoolbox.com/saturated-steam-properties-d_101.html" . The first column is the absolute pressure, the second is the temperature at which water will boil at that pressure. As you can see, at atmospheric pressure (101,33 kPa), water boils at 100°C. To keep it liquid at 120°C, you must increase pressure to at least 200 kPa (so around 100 kPa gauge pressure).

 

[mheslep]

For pure water under standard atmospheric pressure, the boiling point is 100 deg C. Dissolving some other compound in water, such as salts, will elevate the boiling point of the resulting solution. Google "boiling point elevation" for details. The maximum temperature elevation with salts is typically limited by the amount that can be dissolved, ie the saturation point.

Ethylene glycol, aka antifreeze will get you to 120C, but requires 80% glycol.
http://en.wikipedia.org/wiki/Ethylene_glycol
http://hyperphysics.phy-astr.gsu.edu/hbase/Chemical/boilpt.html

 

[russ_watters]

so tell me how can i make a system from
1- pump
2- heater

You're going to have to go into a lot more detail about what you are trying to do if you want us to be able to help you. Could you draw/post a diagram of the system you are trying to build?

 

[maxx_payne]

ok guys i will explain my idea to you
now at my work i have a machine that's used to push the fusible pvc on some aluminium materials , and this aluminium is heated to a temp above 100 c
so pvc needs heat more than 100 and less than 140 to ensure that pvc will stuck on the alominium
and that's is done using a small machine which gives water at 130 or 120 to give the required heat to the pvc aluminium pieces
so all i want to do now is understanding how this unit work ?
it consists of many thermostatic valves , 2 electric heaters , water pump and many connections
so the main problem to me is how to make water pressurized ??
if the pump pumps water to the tank which contain the heater the water will be discharged at atm pressure how can i pressurized water /?

 

[MATLABdude]

Unfortunately, as soon as the water is no longer pressurized (like when you dispense your 120C water to atmospheric pressure) it will very quickly become steam (albeit, steam at 100+C)

Given your description above, can you just use an oven heated to 120C instead?

 

[mheslep]

ok guys i will explain my idea to you
now at my work i have a machine that's used to push the fusible pvc on some aluminium materials , and this aluminium is heated to a temp above 100 c
so pvc needs heat more than 100 and less than 140 to ensure that pvc will stuck on the alominium
and that's is done using a small machine which gives water at 130 or 120 to give the required heat to the pvc aluminium pieces
so all i want to do now is understanding how this unit work ?
it consists of many thermostatic valves , 2 electric heaters , water pump and many connections
so the main problem to me is how to make water pressurized ??
if the pump pumps water to the tank which contain the heater the water will be discharged at atm pressure how can i pressurized water /?

Why does your fluid need to be water? Why not a fluid with a higher boiling point? Oil?

 

[AUK 1138]

you could heat sand in an oven and pour it into your pvc pipe, that would get you the necessary temp and wouldn't have the disadvantages of a steam/water system.

 

[FlexGunship]

Geeze... do I have to do everything?

- Use DOT3 brake fluid

Done. It is roughly as viscous as water, has no corrosive properties. Should be fine.

 

[mheslep]

It's not clear from the description if the purpose of the fluid is apply force to the PVC, heat the PVC, or both. If the fluid is there to apply heat, then take note of its specific heat capacity, as they very widely with all of them less (worse) than water. This means more time will be required (as opposed to using water) to bring the stock PVC up to its application temperature, or increased flow of the fluid over the PVC will be required (if flow is possible)

http://www.engineeringtoolbox.com/specific-heat-fluids-d_151.html