View Full Version : How to measure volumes in a drum...

Bill()C

03-08-2006, 06:56 PM

I think I have this figured out for a drum... doing so in a carboy shouldn't be as hard.

I'm hoping someone can check my logic and math. I'm looking for an easy way to measure how much VO, etc I have in a 55 gallon drum.

A drum is 34" tall.

It can hold 55 gallons.

That works to 1.617647 gallons per vertical inch.

That equals 6.12346 Liters per inch.

That equals 2.4108 L / cm.

I'm not really asking you to look up the conversion, just to confirm that my

logic makes sense.

Therefore I could use a yardstick or some other method and figure out what volume I have.

Whaddya think?

Bill

Bill()C

03-08-2006, 06:56 PM

I think I have this figured out for a drum... doing so in a carboy shouldn't be as hard.

I'm hoping someone can check my logic and math. I'm looking for an easy way to measure how much VO, etc I have in a 55 gallon drum.

A drum is 34" tall.

It can hold 55 gallons.

That works to 1.617647 gallons per vertical inch.

That equals 6.12346 Liters per inch.

That equals 2.4108 L / cm.

I'm not really asking you to look up the conversion, just to confirm that my

logic makes sense.

Therefore I could use a yardstick or some other method and figure out what volume I have.

Whaddya think?

Bill

BiodieselWarehouse.com

03-08-2006, 07:17 PM

Makes sense to me. I use the same method. I also use this method in my appleseed.

Total capacity (i.e. 80 gallons) divided by the height of tank minus 2 inches for insulation on the top and bottom. The oil visible in your process tube/site tube is then simply a ratio to total capacity. 30" inches of oil in a 62" inch 80 gal. tank is 40 gallons. Then the conversions to liters and so on...

Save hundreds on flow meters!

Rich

dkenny

03-09-2006, 01:11 AM

looks good execpt that drums normally hold more than 55 gallons. yes even the 55 gallon ones. this allow for head space(expansion). I think I read on website that a 55 gallon drum actually hold 56 gallons.

if you know the inside diameter of the drum( hopefully the side are straight), determine the area of the circle. use this number * 1 inch think to determine cubic volume per inch.

-dkenny

Joe_M

03-09-2006, 01:49 AM

Or get a plastic drum. You can see the liquid level through the tank, and there are gallon marks on the outside. Very convienient. http://biodiesel.infopop.cc/groupee_common/emoticons/icon_smile.gif

WayneThomas

03-09-2006, 02:10 AM

I use the dipstick method too. I've found that with a 55 gallon drum, one inch equals 1.78 gallons.

22 1/2 inches works out to just a fuzz over 40 gallons which is pretty much the limit in my 55 gallon drum based processer.

40 gallons of oil, 8.8 gallons of methanol (22%) and approximately 2000 grams of catalyst on average. This comes to pretty close to 50 gallons worth of volume. It leaves room for splashing around and when seperated works out to roughly 40 gallons in my wash tank. 10 additional gallons of water per wash and there's still alittle room from the top. Then when about 36 to 38 gallons of wet fuel goes into the drying tank where there's room for the spraying apperatus and the fuel level is low enough that you don't splash fuel all over the place.

Sorry, I kind of got on a roll there. LOL

Wayne

clean and green

03-09-2006, 04:03 AM

The method I used to determine the volume of my mega-size drums http://biodiesel.infopop.cc/eve/forums/a/tpc/f/959605551/m/6491051821 (shameless plug) is:

multiply radius by itself (square the r)

multiply by 3.14 (a good enough approximation of pi for our purposes)

multiply by height of the drum

the result will be the total cubic inches

divide by 231, the number of cu in in a gallon = number of gallons.

a 55-gallon drum comes out to 57.5 gallons by this method. Like you said dkenny the extra space allows for expansion of whatever material was to be put in the drum. The expansion rate of oil is covered in this thread:

http://biodiesel.infopop.cc/eve/forums/a/tpc/f/7196...391082021#8391082021 (http://biodiesel.infopop.cc/eve/forums/a/tpc/f/719605551/m/2551074911/r/8391082021#8391082021)

Also, if you've ever had a drum with the original label on it you will see that drums are filled by weight, not volume, so exact volumes aren't really vital for the manufacturers of, say, windshield washer fluid or orange juice concentrate.

Bobby S

03-09-2006, 12:59 PM

Bio-Texas-DFW started a post last August on this topic. He included a link to an excel spreadsheet. 55 gallon drum break down (http://biodiesel.infopop.cc/eve/forums/a/tpc/f/419605551/m/4011060611/r/6601054611#6601054611)

Mr Ryan Mix

03-09-2006, 02:26 PM

I have found that measurements by calculations have been way off. You might just say that I'm bad at math, which I like to believe is not true, but I calculated my drum with cone to hold about 90 liters and it ended up holding about 120 liters. Inner vs outer diameter, imperfections, cones, and welds can make a big difference over the whole drum.

I ended up filling 2 liter beakers with water one at a time and dumping it in my drum, making graduation marks on a dip stick along the way.

Skeet Shooter

03-09-2006, 03:19 PM

Drum is 6.37 liter/inch and hot water tank is 4 liter/inch approx.

Caddytd

03-09-2006, 06:24 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I use the dipstick method too. I've found that with a 55 gallon drum, one gallon equals 1.78 inches </div></BLOCKQUOTE>

Shouldn't that read 1 inch equals 1.78 gallons? I think that's more correct given the scenario in your post.

WayneThomas

03-09-2006, 06:45 PM

Thanks Caddy, You are right. Blonde moment.

Good lord, I just went back to correct that statement in the post and holy cow! I can't believe the number of errors I made. It's pretty obvious that I didn't re-read that one before hitting the "post now" button.

Wayne

Ratski

03-10-2006, 04:29 AM

I use a the yard stick method and keep it simple stuiped (KISS)I take knowen volum 55 gallons divided by 34"= 1.617647 and then multply it by my measurment on my yard stick to tell me how much WVO I have, I use 19 inches to come up with 30 gallons of WVO. Rich from Biodiesel Wearhouse suggested I keep my batches at 30 gallons, because I am useing a 50 gallon Heater tank and that would allow me room for expansion. I my DIY kit came with a copy of Girl Marks home brewers guide, but I don't remember reading this as a subject but the again if I got it figuared out anybody can do it! Oh by the way Rich thanks for your help gettin me started I have done 5 batches now, and used math skills and electrical skills and carpentry to build my appleseed processer and I get a kick out of every time I learn something new here. Ratski 96 Ram Dodge 2500 Cummins Turbo Bio-diesel

Legal Eagle

03-10-2006, 09:20 AM

This is a copy of an email I received when asking the same question;

..............................................

(I think it is 22.5 inches)...SO....you can take the height in inches time 1.72

and that's the contents in gallons.

................................................

You know that the formula

for calculating the volume of a rectangular tank is

Volume = length x width x depth

answer is in cubic inches/feet/meters ect.

28 X 12 X 12 = 4032

4032 cubic inches = 66 liters

................................................

First you need to convert inches to feet, then multiply your dimensions to

get cubic ft, then multiply the cubic ft by 7.48. There are 7.48 gallons per

cubic foot. Here goes nothing:

12" x 34" x 14" = 1.0 x 2.833 x 1.17 = 3.315 cu. ft.

3.315 x 7.48 = 24.7962 Gal. ( 93.85 L )

................................................

PS - I found that formula for getting volume on a cylidrical tank. It's

similar to the square/rectangle formula as you have to convert inches to

feet & use .785 ( 1/4 of Pi), as well as 7.48 in the equation.

barrel 14" dia x 32 " high

.785 x 1.17 x 1.17 x 2.67 = 2.87 cu. ft.

2.87 x 7.48 = 21.47 gallons

................................................

My 200 liter drum is:

dia 22.25 in = 1.854 ft

.785 X 1.854 (22.25in)X .8333 (10in)= 1.21 cu ft

1.21 X 7.48 = 9.07 gal (34.333 liters)

................................................

.785 X 1.854 (232.25in) X 1 (12in) = 1.45 cu ft

1.45 X 7.48 = 10.89gal ( 41.2 liters)

................................................

Standpipe must be 10 inches high inside drum.

I was trying to figure out how high I needed to make the StandPipe.

Frogmobile

03-10-2006, 09:43 AM

I have been using that method since donkey's years but usisng the venerated and well tested METRIC SYSTEM, this brings another question: Is NASA really sending men on the Moon and probes on Mars in INCHES, YARDS and US GALLONS??

Legal Eagle

03-10-2006, 01:01 PM

I agree that metric is very much simpler, all divisible by ten's (water freezes at 0 and boils at 100, duh), but this is the only thing I had and figured I'd share that.

JLKunka

03-10-2006, 01:57 PM

I have found the "calibrated" drums and carboys to be significantly off. I wanted to be accurate, so I recalibrated a 20-l carboy in 2-liter increments with water from a 2-l graduated cylinder - made new marks with a permanent Sharpie pen.

With the calibrated carboy, I then filled my drum with 150 liters of water and took my depth measurement. This measurement is accurate, and takes into account any dishing of the bottom and the reinforcement bands in the sides.

Lately I got really fancy and added a float switch to turn off my pump when the oil reaches the correct level. The float switch is a Grainger item Float (http://www.grainger.com/Grainger/wwg/itemDetailsRender.shtml?xi=xi&ItemId=1611717439&ccitem=) - a little pricey but will last forever. I switch the current with a relay so the float isn't carrying too many amps. The float is accurate and actuates within 1/16" every time.

BiodieselWarehouse.com

03-10-2006, 02:58 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Ratski:

Oh by the way Rich thanks for your help gettin me started... </div></BLOCKQUOTE>

You are welcome Ratski. I love to Help.

All the best,

Rich

Todd T

03-10-2006, 04:47 PM

I've been in the chemical business for 25 years and my father was in it for 24 years before that. The general rule of thumb is 3" equals 5 gallons in a standard 55 gallon drum. The appropriate fill level is to leave about 3" of space at the top... enough to stick your middle two fingers into the drum and just touch the chemical.

Some suppliers are selling chemical as 53 gallons per drum. Most raw materials are sold and mixed by the pound instead of gallons anyway.

I've been noticing that some drums are taller than others these days. Don't know what's up with that.

Todd T

BiodieselWarehouse.com

03-10-2006, 06:24 PM

I recently found a good source of drums from a guy who imports vitamin E oil from China (he makes vitamin pills). The drums were a little taller and thinner that the standard my thought at the time was that they are for 200 liters. Now I know that oil is sold by the metric ton. Maybe the "tall" drums we see are from China (like everything else these days).

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