Nature’s Furnace Designed to Burn Waste

As thinking “green” for energy sources becomes more necessary and popular, many companies retrofit heating units to accommodate biomass materials. John Kimberlin and his team of engineers created a furnace specifically for biomass — natural wastes from manure to green wood. The first models are being used in Europe, and his company is taking orders in U.S. and Canada.

The heating unit offered by Kimberlin’s Waukee, Iowa, company, Nature’s Furnace, offers a new methodology that should attract the attention of commercial enterprises, including landfills, horse tracks or large farming operations — anywhere there are large piles of waste.

Besides creating energy to run an operation, the furnace’s cost is offset by the eliminated expense of hauling away waste.

“This is a commercial unit,” Kimberlin emphasizes. The computer-controlled furnacecan consume more than 400 pounds of waste per hour; it’s not intended for residential customers. But in the future, his biomass reactor may provide not only heat and heated fluids that can be used for cooling, but also electricity that could be sold to consumers.

“We use air to fire it, so there’s no other parasitic energy being used,” Kimberlin explains. “It only takes minimal electricity to run it.” Run wide open he says it takes about $5/day in electricity, but generally, it is only half that cost.

To start the furnace initially, material is fed from a hopper into the furnace with augers and vibrators. To fire it, a button is pushed that turns on strip heaters (like coils on an electric range) that are encased in stainless steel. The heaters are 1,200 degrees and after 10 minutes they ignite the biomass. The heaters are turned off, and the biomass continues to burn, similar to a hay fire. A thermostat controls a combustion fan to add air, automatically kicking on and off to maintain steady heat.

“It’s just like an old forge,” Kimberlin says. The furnace burns up to 1,300 degrees, which makes it extremely clean with virtually no smoke or odor.

The heat exchange is inside the combustor — furnaces can be set up for air or fluid heat. One hundred pounds of waste per hour converts into about 175,000 btu’s for hot air heat. For fluid heat, the furnace can handle 200 pounds of waste per hour for 400,000 btu’s.

Because the exchanger is in the combustion zone, it is more efficient, produces more btu’s and the exterior of the furnace stays cool.

Since the biomass dries from the heat of the combustion, the furnace burns high moisture biomass — up to 75 percent. Plus, it doesn’t malfunction from contaminants such as rocks and dirt, which sets it apart from other units that tend to clog up.

"It’ll burn any kind of biomass,” Kimberlin says.

He knows that it works from experience. The former horse trainer rented out his livestock facility for two years while he took another job. When he returned, he had a mountain of manure and bedding.

“I knew the waste had some type of heating potential, and I needed heat in my buildings,” Kimberlin writes on his web site (naturesfurnace.com).

He focused on heating from the center of the biomass and came up with a simple mechanism with only a few moving parts — augers and fans to move the biomass in and the ash and contaminants out; and a pump for a fluid unit or fan for an air unit. He applied for and received a 20-year patent for being the first to exchange energy from within a solid fuel mass.

“What makes it unique is that it’s very small and very simple,” Kimberlin says. The furnace can be placed where the waste is, instead of moving the waste to it.    The furnace burns clean. About 3 percent of the weight of material going in comes out in potash, which can be spread on the fields. That equals a small handful of ash for 1 cu. ft. of sawdust, Kimberlin says. Rocks and other non-burnable contaminants also auger out as waste.

Kimberlin gathered a group of investors to create Nature’s Furnace. And he has surrounded himself with engineers to refine his creation and meet EPA and government standards. They are working with micro thermal technology to create electricity. He established export markets and delivered furnaces to be used in poultry, equine and even a mushroom business.

It’s taken years to develop Nature’s Furnace, but with interest in green energy, the timing is right. Kimberlin likes to call biomass “Mother Nature’s battery,” and his furnace takes advantage of it in a very simple way.

Contact: John Kimberlin, Nature’s Furnace Inc., 33434 Ute Ave., Waukee, Iowa 50263 (515-987-2397, www.naturesfurnace.com)