Coal Density

coalmaster wrote:Its quoted in the first post of this thread

All I can see is 2 ebay links nothing else shows up as a link.

coalmaster wrote:Lehigh coal primrose vein

First lump. D=m/v. 1.40=25.09/17.8

Second lump. 1.52=23.664/15.5

The load from this vein looked to me to be higher quality by looks alone. I only burned for a week before I dumped the mammoth vein load on top. Both burn great are very very low ash

Edit: this test was conducted twice because I somehow mixed the two lumps with mass volume each lump gain about .5 grain of water weight just from sitting in the cup for a few seconds

Very interesting. You only have to weigh the coal once when it is dry no? Do you feel you getting the volume measured to a tenth of a cc or so and that the difference from lump to lump is real? My measurements only average over several nuts. The average of these two pieces in the primrose vein, 1.46, is closer to what Paulie thought premium coal should be. Do you have time to make a measurement like mine? Get a tall glass. put a mark on it half way and fill with water. Weigh it as a zero point. Add several pieces of coal (totally submerged of course), and weigh again giving the coal weight. Mark new water level. Empty glass. Fill with water to second mark. Weigh. Now you have the weight of the coal and the weight of the water that has the same volume as the coal. Divide coal/water. It should be very accurate if you have a nice tall glass and mark the water level very carefully. Just for fun.

ddahlgren wrote:

coalmaster wrote:Its quoted in the first post of this thread

All I can see is 2 ebay links nothing else shows up as a link.

No link just pasted text. You may find it interesting because you started the ahem... "discussion" that lead to its posting.

The curse of working in engineering everything is both a puzzle and a question that is a are you sure show me the numbers. Spring summer and fall tons to do outside winter is a pain for me everything hurts and BP meds make me sensitive to cold. When it snows and shovel out to get food it looks like I am stocking a bunker LOL. All I need for the next 7 to 10 days... Will give it a look as need to get in a few hundred pounds in buckets clean the ash vac then get the fly as out of the stove. I go distracted this morning and forgot morning tending and lost the fire but it is warm here and a good day to catch up on maintenance.

All I know is no matter what next stove I get it has to have grates that do not require hands and knees with a selection of pokers to clear them. I have no idea how windyhill keeps his 404 running all winter with no shut down DCrane as well no doubt. At 63 with bad knees and 1 wounded hip the hands and knees drill is getting real old at the beginning of second season. Without getting beyond PG13 the greatest feature of coal for me is evening last night a adorable lady came over for dinner and a movie and started shedding clothes as a bit warm LOL..

ddahlgren wrote:All I know is no matter what next stove I get it has to have grates that do not require hands and knees with a selection of pokers to clear them. I have no idea how windyhill keeps his 404 running all winter with no shut down DCrane as well no doubt. At 63 with bad knees and 1 wounded hip the hands and knees drill is getting real old at the beginning of second season.

Here is how I deal with working on my hand fired stove. I bought this bench for my wife to work in her garden.

In the winter it comes in the house. I set it in front the stove, sit down when I open the ash door and watch things liven up before the shake down. Once the stove is up to temp, I flip the bench over into the kneeling position. This way I can easily shake it down and watch the condition of the ash drop. Once done shaking things, I can grab the bench handles and get up without complaining about the state of the world.

http://www.gardeners.com/buy/deep-seat-garden-kneeler/40-009.html?start=15&q=bench

coalmaster wrote:From paulie's post I believe that specific gravity can be used to determine coal quality.

Although a good indicator , since some coal seams have a little higher inherent density than others , specific gravity along with BTU testing in my opinion is my preference.

By simply adjusting the gravity on a pile of mine run, I could process the same 12,700 BTU pile to fit a standard anthracite order running a gravity of 1.58 , bump up the gravity to fill a 10,000 BTU power plant spec, and take it up to 1.7 or higher to make a 7500 BTU Co- gen product.

Sometimes the gravity in a preperation plant gets a little out of line thru equipment failure resulting in a partial run of higher gravity, lower BTU coal accidently mixed in.

I did find a partial bucket of the quick test media that I used for quick checks and tests over 20 years ago.
Unfortunately, I still haven't located my hydrometer to test it's actual gravity. I did happen to find two mason jars that I recall using to demonstrate the same same sample ran at two gravitys for a powe plant customer.

As I recall , the BTU difference between the lower gravity and the higher gravity run was around 700 btu

In the jar on the left with the lower gravity, almost half of the sample was rejected. The only thing rejected at a higher gravity was the rock and dirt fragments.

Paulie
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Snotzalot wrote:

ddahlgren wrote:All I know is no matter what next stove I get it has to have grates that do not require hands and knees with a selection of pokers to clear them. I have no idea how windyhill keeps his 404 running all winter with no shut down DCrane as well no doubt. At 63 with bad knees and 1 wounded hip the hands and knees drill is getting real old at the beginning of second season.

Here is how I deal with working on my hand fired stove. I bought this bench for my wife to work in her garden.

In the winter it comes in the house. I set it in front the stove, sit down when I open the ash door and watch things liven up before the shake down. Once the stove is up to temp, I flip the bench over into the kneeling position. This way I can easily shake it down and watch the condition of the ash drop. Once done shaking things, I can grab the bench handles and get up without complaining about the state of the world.

http://www.gardeners.com/buy/deep-seat-garden-kneeler/40-009.html?start=15&q=bench

Excellent idea - thanks SA.

Melissa has a gardening bench just like it and she doesn't need it during coal season. Maybe she'll share it when the #6 is up and running.

Another saving grace of a range is that the grates are higher off the floor, 'cause I'm a year older than Dave, also with bad knees and hip. If I had to get down on the floor to clear grates that low I'd be there until Spring, if somebody didn't rig a block and tackle !!!

Paul

lobsterman wrote:

coalmaster wrote:Lehigh coal primrose vein

First lump. D=m/v. 1.40=25.09/17.8

Second lump. 1.52=23.664/15.5

The load from this vein looked to me to be higher quality by looks alone. I only burned for a week before I dumped the mammoth vein load on top. Both burn great are very very low ash

Edit: this test was conducted twice because I somehow mixed the two lumps with mass volume each lump gain about .5 grain of water weight just from sitting in the cup for a few seconds

Very interesting. You only have to weigh the coal once when it is dry no? Do you feel you getting the volume measured to a tenth of a cc or so and that the difference from lump to lump is real? My measurements only average over several nuts. The average of these two pieces in the primrose vein, 1.46, is closer to what Paulie thought premium coal should be. Do you have time to make a measurement like mine? Get a tall glass. put a mark on it half way and fill with water. Weigh it as a zero point. Add several pieces of coal (totally submerged of course), and weigh again giving the coal weight. Mark new water level. Empty glass. Fill with water to second mark. Weigh. Now you have the weight of the coal and the weight of the water that has the same volume as the coal. Divide coal/water. It should be very accurate if you have a nice tall glass and mark the water level very carefully. Just for fun.

what I'm doing is placing a cup full of water in a bowl. Now I take the medicine dropper and add water until I cant add anymore without over flowing. Once it is within a few drops of spilling I slowly drop the lump into the cup. Then the cup is removed from the bowl and the medicine dropper is used to draw the displaced water from the bowl

I don't have a scale like yours that can measure about a lb.

coalmaster wrote:I don't have a scale like yours that can measure about a lb.

Too much weight for powder?
Technique sounds OK but then how do you measure the water? Hopefully you weigh it. If the water capturing vessel was light enough you could just weight it. I have a better suggestion for you.
Get a tiny plastic cup that your scale can handle the weight of in water and can hold the coal piece submerged. Now make 3 weighings: A) coal piece alone, B) cup full of water, C) cup + coal full of water.
Your "zero point is now C - A. The density is A / (A + B - C ) . I think it should be much easier.

lobsterman wrote:

coalmaster wrote:I don't have a scale like yours that can measure about a lb.

Too much weight for powder?
Technique sounds OK but then how do you measure the water? Hopefully you weigh it. If the water capturing vessel was light enough you could just weight it. I have a better suggestion for you.
Get a tiny plastic cup that your scale can handle the weight of in water and can hold the coal piece submerged. Now make 3 weighings: A) coal piece alone, B) cup full of water, C) cup + coal full of water.
Your "zero point is now C - A. The density is A / (A + B - C ) . I think it should be much easier.

I'm actually checking the volume of the water that is displaced in millileter which equals cm^3. My density is in grams/cm^3. Are you assuming that the weight of the water displaced is equal to the mass of the coal? Or are you converting somehow from weight to mass?

[/quote]
I'm actually checking the volume of the water that is displaced in millileter which equals cm^3. My density is in grams/cm^3. Are you assuming that the weight of the water displaced is equal to the mass of the coal? Or are you converting somehow from weight to mass?[/quote]

The weight of the water displaced is the VOLUME of the coal times the density of water.
A is the weight of the coal.
C - A is the weight of the water before the coal is added
B - (C - A) is the weight of the water that has the SAME VOLUME as the coal
A / [B - (C - A)] is the weight of coal divided by weight of same volume of water = density of coal relative to water, the so-called specific gravity

lobsterman wrote:

I'm actually checking the volume of the water that is displaced in millileter which equals cm^3. My density is in grams/cm^3. Are you assuming that the weight of the water displaced is equal to the mass of the coal? Or are you converting somehow from weight to mass?[/quote]

The weight of the water displaced is the VOLUME of the coal times the density of water.
A is the weight of the coal.
C - A is the weight of the water before the coal is added
B - (C - A) is the weight of the water that has the SAME VOLUME as the coal
A / [B - (C - A)] is the weight of coal divided by weight of same volume of water = density of coal relative to water, the so-called specific gravity[/quote]
So am I doing it right?

coalmaster wrote:

lobsterman wrote:

I'm actually checking the volume of the water that is displaced in millileter which equals cm^3. My density is in grams/cm^3. Are you assuming that the weight of the water displaced is equal to the mass of the coal? Or are you converting somehow from weight to mass?

The weight of the water displaced is the VOLUME of the coal times the density of water.
A is the weight of the coal.
C - A is the weight of the water before the coal is added
B - (C - A) is the weight of the water that has the SAME VOLUME as the coal
A / [B - (C - A)] is the weight of coal divided by weight of same volume of water = density of coal relative to water, the so-called specific gravity[/quote]
So am I doing it right?[/quote]

Yes you are doing it correctly. My suggestion was merely meant to be an alternate technique that might be easier.

The bigger the sample you guys use, the more accurate it will be. I'd try it with 10 pounds of coal.

The same technique was used hundreds of years ago to make sure the King's crown was pure gold.