Slash Management

CUSP Installs Air Curtain Burner in Divide

Air Curtain Burner Installed at Divide Slash Site
After the 2002 Hayman Fire, a slash site was set up in eastern Teller County to help residents clear their properties of potential fire fuels. The community responded and the site soon had to be moved to accommodate the materials being brought in. A new site was centrally located in Divide and run by Teller County. CUSP assisted the county by coordinating and managing volunteers at the site. Continued and growing public use required a more formal business model for running the site and CUSP took over management of the slash site while working closely with Teller County government.

For the last decade the site has typically been open 3 days a week from May through October. Operations have been consistent with notable increases in usage during droughts and fire years, like 2012 when the Waldo Canyon Fire ignited in neighboring El Paso County.

The site provides homeowners a place to bring the slash they accumulate while creating defensible spaces around their homes and thinning wooded areas on their properties to make them more resilient, the collected material are still fuels.  Disposing of the slash from the site can be costly. Current procedures for slash removal require contracting with a local company  to grind the slash and reduce it to chips, the bulk of which must be hauled away.

firebox-principleThis process can easily cost $15,000 for a regular season’s worth of slash. The modest per load fees  ($10 in Divide) barely cover the costs of running site. CUSP and Teller County want to keep the fees affordable to encourage continued use of the site without creating an undue burden on property owners who regularly use the site because they are appropriately maintaining their properties while mitigating fire threats.

In an effort to meet the fiscal challenges of safely and efficiently operating the site for the benefit of residents, CUSP explored and pursued the use of an Air Curtain Burner at the site. The curtain burner meets CUSP’s requirements for environmental responsibility while maximizing our financial investment in a product that will quickly recoup the purchase cost.   The burner was purchased and installed in Divide in late 2016. After waiting for ideal weather conditions, the first loads were burned on January 20th and 21st.

CUSP will use the remainder of the winter months to become fully acquainted with the machine, its capabilities and limitations, if any.  Safety is at the core of all CUSP’s standard operating procedures and is certainly a priority in the use of the air curtain burner. While the manufacturer provides detailed instructions and support, CUSP is adding protocols for use in our environment.  The processes and results will be clearly documented and refinements  and adjustments will be incorporated when appropriate and advantageous. We look forward to reporting the results and date from our first winter’s use of the air curtain burner later this year.

Air Burners Inc., gives a succinct description of how this machine works –  Air Curtain Burners, also called FireBoxes, were designed principally as a pollution control device. The primary objective of an air curtain machine is to reduce the particulate matter (PM) or smoke, which results from burning clean wood waste. It is sometimes hard to visualize without seeing a machine in operation, but the machines do not burn anything, rather they control the results of something burning. You could look at it as a pollution control device for open burning.

Clean wood waste is loaded into the FireBox, and an accelerant is poured onto the wood and the pile is ignited. This is very similar to starting a campfire. The air curtain is not engaged until the fire has grown in strength or the air curtain may blow the fire out. Once the fire has reached suitable strength, usually in 15 to 20 minutes, the air curtain is engaged. The air curtain then runs at a steady state throughout the burn operation and the waste wood is loaded at a rate consistent with the rate of burn.

The purpose of the air curtain is to stall or slow down the smoke particles on their way out of the FireBox. In doing this,  the particles are subjected to the highest temperatures in the FireBox. Stalling the smoke particles in this region just under the air curtain causes them to re-burn, further reducing their size to an acceptable limit. The result is a very clean burn with opacities well under 10% per EPA Method 9 Testing (as compared to open burning which typically can run at 80% to 100% opacity).

Categories: Slash Management