Raising boiling point of salt water

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Discussion Overview

The discussion revolves around the feasibility of raising the boiling point of salt water to 325 degrees Fahrenheit at 28 PSI, particularly in the context of plasticizing animal horns using a pressure cooker. Participants explore the limitations of using salt water and alternative methods for achieving the desired temperature without compromising safety.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Experimental/applied

Main Points Raised

  • One participant inquires about the amount of salt needed to raise the boiling point of water to 325 degrees at 28 PSI, noting a basic understanding of boiling point elevation due to increased particle concentration.
  • Another participant asserts that no amount of salt will achieve the desired boiling point, referencing a Dühring plot that indicates a maximum increase of about 10 degrees Celsius with saturated NaCl.
  • Concerns are raised about the safety of using highly pressurized boiling water and the appropriateness of pressure cookers for such applications.
  • A participant expresses a need to avoid direct heat to prevent brittleness in the horn and seeks alternative methods to create moist heat above 300 degrees.
  • Food safe glycerin is suggested as a potential alternative, with a boiling point significantly higher than 300 degrees, and a mixture with water is proposed to achieve the desired temperature.
  • Another participant warns against working at elevated pressures, comparing the risks of using a pressure cooker versus an autoclave.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the best method to achieve the desired temperature safely. There are competing views on the effectiveness of salt water versus glycerin, and concerns about safety remain unresolved.

Contextual Notes

Limitations include the uncertainty regarding the safety and effectiveness of using glycerin, the dependence on specific pressure cooker designs, and the unresolved nature of achieving moist heat above 300 degrees without risking safety.

Who May Find This Useful

This discussion may be of interest to individuals exploring methods for plasticizing materials, those working with pressure cooking techniques, and participants in experimental applications involving heat and pressure.

shofarsogood
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How much salt per quart does it take to raise the temperature of water to 325 degrees at 28 PSI?

I am sorry to say I am not educated in physics but I do understand the more particles in the water the higher the boiling point. I am trying to plasticize animal horns in a pressure cooker with a maximum pressure of 28 psi.

Thank you for making this kitchen table ready !

Shalom

Shofarsogood
 
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Answer: No amount. Look at a Dühring plot; saturating water with NaCl only raises its boiling point by about 10 degrees C. You can't get up to 325 F without pressures substantially larger than 28 psi.

Then there's also a quite obvious concern about having highly pressurized boiling water around, and using pressure cookers in ways they're not intended.

Why not just use oil instead?
 
Thanks, for the prompt reply. The dilema is not to cook the horn by using direct heat. I am concerned about the horn becoming brittle. I know it is possible to soften the solid tip deep enough to straighten it sufficiently to drill and form a mouthpiece.

The particular pressure cooker I am using has two saftey devices integral to keep it safe. One is set at 28 lbs PSI, the other is at 40 PSI, (and is not mechanical but a failure point of a rubber plug in case the first fails). The tank itself can go much higher, well over 100 psi without failure. I contacted the design department first to make sure I was not in danger.

Not sure if food safe glycerin would work?

Are there other ways to create moist heat above 300 degrees? I thought about super heating steam.

Any help would be appreciated. The horn is keratin much like a tough fingernail.


Thanks
 
shofarsogood said:
Not sure if food safe glycerin would work?

That'd work. It's got a boiling point well over 300 (554 F). If you must have some water in it, you could add about 5-10% water (by weight) and get a boiling point at about 300 degrees at atmospheric pressure, according to http://www.dow.com/glycerine/resources/table16_91100.htm" . Should be fairly easy to test yourself, on a stove with a thermometer.

Are there other ways to create moist heat above 300 degrees? I thought about super heating steam.

Yeah well that's what you'd need with just water or water/salt. Most autoclaves don't go that high even (and if you've seen one, they're a lot sturdier than a pressure cooker.) I'd strongly recommend against working at elevated pressures. Worst case scenario doing it the first way is a spill, worst case the latter way means an explosion.
 
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