 |
|
||||||||||||||||||||||||||||||||||||||||
 | ||||||||||||||||||||||||||||||||||||||||
Energy to dry firewood
|
||||||||||||||||||||||||||||||||||||||||
| Estimated weight of green firewood: (Oak=5000lbs, Maple=4700lbs, Hickory=5000lbs, Birch=4300lbs = average 4750 lbs/cord |
4750 lbs/cord |
| Estimated weight of dry firewood: (Oak=3800lbs, Maple=3700lbs, Hickory=3800lbs, Birch-3000lbs, average 3575 lbs/cord |
3575 lbs/cord |
| Amount of water extracted per cord of firewood to become dried. | 1175 lbs |
| How much energy will it take to evaporate 1 lbs of water: Starting temperature is 60F. Raising 1 lbs of water from 60F to 212F = 152btu (1btu = 1F per lbs) Evaporating 1 lbs of water at 212F = 971 btu. Total energy needed to evaporate 1 lbs of water from 60F = 1123 btu First it there is a heat waste factor in any kiln. Basically you will need significantly more heat to get this done due to heat energy escaping during venting, walls, floor, and other inefficiencies. The rule of thumb in lumber drying is 35-60% waste factor. this means it will cost between 1700 to 2800 btu to evaporate 1 lbs of water in a kiln. |
|
| How much energy does it take evaporate 1175 lbs of water from firewood: Theoretical: 1175 lbs of water x 1123 btu/lbs = 1.3 million btu (not possible) LOW Estimate: 1175 lbs of water x 1700 btu / lbs = 2.0 million btu HIGH Estimate: 1175 lbs of water x 2800 btu / lbs = 3.3 million btu |
between: 2 million btu and 3.3 million btu |
| How much energy does it take to raise 1 cord of firewood from 60F to about 212F: Average weight of firewood dry (without water) = 3575 btu Temperature increase is (212F - 60F) = 152F increase Approximately 1 btu / lbs / 1F increase. Total energy needed to raise wood temperature (3575 lbs x 152 btu/lbs) = 543400 btu. |
approx. 550,000 btu. |
| Total energy consumption to dry 1 cord of firewood: LOW estimate: (2,000,000 + 550,000) btu = 2.6 million btu HIGH estimate: (3,300,000 + 550,000) btu = 3.9 million btu Kiln-direct MiniQuick Firewood kiln will be very close to the LOW estimate as that kiln design relies on "boiling" the water out of the wood and letting the "steam" escape instead of venting. |
|
| TOTAL COST IN ENERGY TO DRY ONE CORD OF WOOD IN THE MINIQUICK FIREWOOD KILN |
2.6 million btu. |
| Estimated cost of energy with wood waste: This will use about 1/8 cord of wood waste (cost per cord = $0-$100) |
Nothing to $15.00 |
| Estimated cost of energy using LPgas Each gallon of LP gas = 91000 btu / gl LPgas The kiln will need (2,600,000 / 91000) = 28 gal of LP gas Estimated cost per gallon of LP gas: $1.40 (this will probably increase) Total cost to dry firewood with LP gas (28 gal x $1.40/gal) 39.00 |
Approx $40.00 |
New Wood waste heat system for your kiln and warehouse - See test pictures.
New SlimLine Heat recovery systems added to our product line - See Online Store.
September 9th-11th: Lake State Logging Congress and Equipment Expo - Green Bay, WI - come visit us at our booth.
September 17th-18th: Kentucky Wood Expo 2010 - Madisonville, KY - come visit us at our booth.
October 1st-3rd: Paul Bunyan Show - Cambridge, OH - come visit us at our booth.
Copyright 2002-2010 Kiln-direct.com
All rights reserved
Powered by SalesKite
Search our site:
