Specific heat

30 November 2003, 06:25

bartsche

Specific heat

Is there any information out there with the specific heat of each powder? Calories /gram or ft.lbs./lb or BTUs/ any other measure of mass or weight? I'm looking for a comparative anaysis; maybe something that has been done in a bomb calorimeter. [Smile]

30 November 2003, 14:00

Nitroman

You can telephone them or send a nice letter asking for that information. They would definitely have it.

30 November 2003, 15:11

john17

ahh yes thermodynamics. Gosh i hate chemistry. Sorry i cant help you buddy i found nothing in my references.

30 November 2003, 15:59

Clark

I see the defintion of specific heat has not changed since I was in high school in 1967:
http://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=%22specific++heat%22+definition&btnG=Google+Search
The amount of energy (measured in calories or joules) needed to raise thetemperature of one gram of a pure substance by one degree C.

Looking at the heat of combustion:
http://www.google.com/search?hl=en&lr=&ie=UTF-8&oe=UTF-8&q=%22heat+of+combustion%22+definition&btnG=Google+Search

The quantity of heat liberated per gram-molecular weight when a substance undergoes complete oxidation.

30 November 2003, 18:02

bartsche

quote:
Originally posted by Nitroman:
"You can telephone them or send a nice letter asking for that information. They would definitely have it."

Who NITROMAN???????? Each individual powder manufacturor? [Roll Eyes]

30 November 2003, 18:30

Grandpasez

One grain of medium to slow powder has about
170 to 180 ft lbs of energy(depending on coatings and amount of nitroglycerin added) if converted to work at 100% effiency.Most in rifles calibers range between 25 to 40% effiency, depending on volumetric effiency..Ed.

01 December 2003, 17:26

bartsche

OK What I am looking for is COMPARATIVE published data indicating the individual specific heat of each powder.

Does such a thing exist?
What you learned in high school is interesting but not pertenant. The definition of specific heat is great but already known.Is there anyone out there who can cut the meat and get to the eating? Maybe it doesn't exist???????? roger [Wink]

02 December 2003, 09:53

Stonecreek

I've never run across any information on calories/unit of mass comparing individual powders. In the few references I have seen, most powders have very close to the same energy content, regardless of buring rate. The fast, double-based (nitroglycerine/nitrocellulose) powders tend to be a trifle more energetic than a slow single-based like, say, IMR 7828; and some powders claim "high energy" like the Vhitavorri N500 series, but they post no specs for these "high energy" powders, so I have my doubts.

Sorry I can't be more helpful, but if you do run across any energy specs, please be so kind as to post the source for the rest of us.

Good luck.

02 December 2003, 10:11

Fireform

My understanding is that the specific heat and total energy released is broadly similar across the whole range of powders, but that the rate of energy release varies due to particle shape, surface area/volume variations and the surface coatings on the grains. That's why, for instance, the slow burners are cylinders or spheres, but not flakes.

If what I remember is really the case, you may not find out very much that's useful from specific heat measurements. Remember, thermodynamics doesn't tell you about kinetics.

02 December 2003, 11:25

DigitalDan

One of the older issues of Handloader Digest has this info., but it contains no data for newer powders. If I can find it I'll post the reference.

02 December 2003, 14:46

NotRicochet

I've got the complete specific data on Olin's WC (Western Cartridge) Ball powders mostly in the 600-800 number series, forwarded to me years ago by a Shooters board member who got it from one of the NRA's Dope Bag editors still more years earlier. Most of the numbers on it are industrial/military powders not released commercially. E-mail me, Roger, with your address and I'll hunt this thing up and make you a copy. Or I can type up the info online for the few powders corresponding to commercial Winchester powders like 231, 680, 748, 760, 785. (Commercial blended powders might or might not conform to these original specs.) Also, (of considerable interest to me), the big slow burners like WC860, WC870 (H870), and WC872 are on there. Several other surplus powders of interest like WC820 and WC852 are in there. The slowest on the list is WC875, another 20mm powder. Olin listed several interesting parameters including the heat content, impetus (given in foot pounds per lb, I think), and flame temperature for these powders. I sure wish I could find comparable data on other powders like the IMR series!

I may have to hunt a bit for this stuff, since my wife took over my loading book shelf for a boatload of Beanie Babies and my data got moved.

02 December 2003, 16:17

bartsche

Something told me you'd be the one, John [Cool]

roger

02 December 2003, 18:08

John Ricks

Ahhh, another one for QuickLoad, the gem of internal ballistics software.

QuickLoad calculations are just Thermodynamics and a pressure vessel.

In the QuickLoad data base is a spec sheet for each of the listed powders, with all the jucy thermodynamic stuff.

02 December 2003, 18:45

Clark

bartsche,
"specific heat" is not what you want.

(change in temperature) X (mass in grams) X ( specific heat (Cp)) = Heat Energy

Here is much the same experiment for specific heat they showed us in Physics 100 in 1970:
http://chemlearn.chem.indiana.edu/demos/SpecHeat.htm

Notice how the Aluminum melted deepest?
That is because it had the highest specific heat.
It was also the tall one [low density]

--
A society that teaches evolution as fact will breed a generation of atheists that will destroy the society. It is Darwinian.

03 December 2003, 07:41

bartsche

[QUOTE]Originally posted by Clark:
[QB]"bartsche,
"specific heat" is not what you want."

Clark, You are absolutly right. I used the wrong term.

Do you have any specific information that I can use? roger [Smile]

03 December 2003, 19:23

Clark

Quickload lists many variables for powders, of which I do not understand the signifigance, but the "Heat of exposion /potential varies from 6000 KJ/Kg in some fast powders down to 3500 in some slow powders.

04 December 2003, 03:00

DigitalDan

TESTING POWDERS FOR TOTAL ENERGY by Ed Yard, HL Digest 10th Ed. may have some of what you seek. Luck.

04 December 2003, 09:01

bartsche

Thanks guys. I think I have what I was looking for. [Big Grin]

04 December 2003, 19:07

Vibe

quote:
Originally posted by bartsche:
Thanks guys. I think I have what I was looking for.

Great!! Now////care to post it or provide a link so the rest of us can catch up? LOL. [Wink]

05 December 2003, 13:17

bartsche

quote:
Originally posted by Clark:
""Heat of exposion /potential varies from 6000 KJ/Kg in some fast powders down to 3500 in some slow powders."[/QB]

This really is a lot of what I wanted. It indicates there is a vast difference.

next: DigitalDan is sending me the info from HL Digest 10th editon. I'll see where it goes from there and I will share what I wind up with you.

I'm looking to invest some money into a small project but before I got to deep into it there were a number of things I needed: burn rate, density, and energy content of powders were but three but were I think the most important. It appears at the moment that the powders I'll be focusing on fall between the 4198s and WC 844 on the burn rate charts.

If my goals are attainable and it works I'll share that also.
If it doesn't i'll just practice being humble.
[Roll Eyes]

roger