Agrilab Technologies Inc, (AGT) a leader in compost heat-recovery technology, has recently installed a next-generation compost heat recovery system at Vern-Mont Farm in Vernon, Vermont. The Drum Dragon 200™ system generates continuous combustion-free hot water from the aeration exhaust of an aerobic rotary drum compost system, reducing propane use on the farm for milk-parlor washing.
“We installed the composting drum last year and I kept looking at all that hot exhaust steam coming out of the drum thinking there must be something we can do with that heat, and then we learned about Agrilab Technologies,” said Jeff Dunklee, co-owner of the farm.
The Drum Dragon 200 compost heat recovery system is designed specifically for the rotary drum compost systems that are becoming more common on farms and commercial compost sites. It can capture up to 120,000 Btu/hr continuously depending on the size of the drum it is connected to and the amount of hot water being used on the site.
A computerized web connected data system tracks real time water temperatures and other operational data points making it easy to track performance or adjust aeration fan speeds to increase or decrease the hot water produced. Typical compost exhaust vapor temperatures range between 140˚F and 160˚F, with hot water temperatures up to 150˚F.
The amount of heat recovered by the Drum Dragon varies depending on the hot water use patterns at the farm. At the Vern-Mont Farm the Drum Dragon preheats a 120 gallon tank of water to up to 150˚F. The farm’s hot water demand cycle results in an average of 30,000 Btu/hr of continuous heat recovered.
The energy that can be captured by a Drum Dragon 200 can be worth more than $15,000 per year compared to $1.20 per gallon propane prices, depending on hot water use patterns of the site. With existing financing programs this technology can be immediately cash-flow positive for farms, saving money to help offset low milk prices and other financial pressures on dairy farms.
Published in the August 2016 Edition of American Recycler News