Topics Mentioned in This Article
- What is an air curtain incinerator?
- How an air curtain incinerator works
- The benefits of using an air curtain incinerator
- How to set up an air curtain incinerator
- How to get a burn permit
Also read our Air Burner Instructions page.
Air Curtain Burners are revolutionary in the world of debris management- and most specifically when it comes to waste burning.
What Is An Air Curtain Incinerator?
In short, air curtain incinerators, or air curtain burners, are pieces of equipment that create a fast-moving curtain of air across the top of a burn pit, trench, or refractory box. (A refractory box looks similar to a large dumpster from the outside, but inside it is lined with a special, heat-resistant refractory material.)
How Does a Trench Burner or Air Curtain Incinerator Work?
The air curtain incinerator, also sometimes called an air curtain destructor, is a relatively simple machine. It is comprised of an engine and fan and a manifold (A manifold is the long tube or pipe that the air comes out of. It either lines up with the length of the trench/pit or lines the top of the refractory box) The large fan and ventilation system forces the air through the manifold at high speeds. This creates a fast-moving curtain of air across the top of the pit, trench, or self-contained box. Once the air blows from the manifold, it bounces off the opposite walls, then circulates into and feeds the fire. The smoke and sparks stay trapped beneath the air curtain. (unless it is temporarily broken by debris being dropped into it. Once the debris has fallen completely under the curtain, the curtain once again becomes a complete sheet of air.)
What is the Benefit of an Air Curtain Incinerator?
An air curtain incinerator, or air curtain burner, has many benefits.
First, when you use an air curtain incinerator it creates a much hotter and more efficient furnace within the pit or trench that you have dug. This is possible thanks to the fresh oxygen being funneled into the flame through the curtain of air.
Second, air curtain incinerators create a much cleaner and safer burn. Due to the fast-moving curtain of air, smoke and sparks are trapped in the pit- beneath the curtain. The only time that they can break through is when additional debris is dropped into the fire through the curtain of air. This is one of the reasons why burning vegetative debris with the help of an air curtain incinerator is shown to have significantly lower emissions of particulate matter and CO per unit compared with debris being burned in an open pile.
For these reasons, it is normally easier to obtain a burn permit when you are using an air curtain destructor. For information on obtaining a burn permit, check our State and county contact pages, where you will find the relevant names, phone numbers, and general contact information for different states and their counties.
Beyond the ecological benefits, burning is a desirable option to other forms of debris removal for a few main reasons.
First, burning debris means you have a much smaller by-product. The ash pile that you will be left with once the burning is complete is radically smaller than if it were ground or chipped.
Second, the clean-up process is very simple since all that is normally required is covering the pit back over with the dirt you took from it. You can also repurpose the ash. There are lots of surprising uses for ash in the marketplace. You can see some of those here on our page How To Repurpose Ash. Regardless, this is simpler than carting off the debris, locating a dump site, and then having to pay fees to dump it there.
How Can I Set Up an Air Curtain Incinerator?
The first step is to build your burn pit.
While regulations differ depending on locality, most require your pit to be approximately 300 feet from roads and other structures. Often, this distance is required even if the structure is uninhabited or unused.
The length of your pit should be the same length or slightly shorter than, the length of your manifold. If you are extra nervous about smoke getting out on the side, you can simply make your pit slightly shorter than the manifold on each side, but this isn’t really necessary. It should be approximately 9 feet wide and 10 – 15 deep. This width and depth should allow you to still get proper air circulation throughout the pit. These are average measurements, and can differ slightly according to local laws. If there is not enough space to dig down to these depths, it is often possible to dig down part of the way and build a berm up, so that the walls of your pit come above what is normally ground level. Using this method, our clients have burned it many areas with high water tables, such as throughout south Florida.
The most critical points are that your pit is:
- deep enough to fit debris under the curtain of air while it is burning
- your manifold is not shorter than your pit, since the curtain of air would be unable to fully cover the burn, allowing smoke and sparks to escape through the side(s).
Next, it’s best to have an estimate of the duration of your project, since it may be necessary to reinforce your pit’s walls. The type of soil you have will make a big difference in how long the walls will last. If you have a short-term burn (a week or less) then, typically, it is not necessary to reinforce the sides of your burn pit. However, if you will be burning long-term, reinforcement is often needed to prevent the walls of your pit from caving in. DO NOT use common cement blocks to reinforce your pit. These have been known to explode and send chunks of concrete flying 30 feet. Obviously, you also would not want to reinforce your pit or trench with wood, since it will combust along with the debris. Be sure that anything you use is rated for high heat. There are blocks rated for high heat.
At this point, you can set up the air curtain burner.
Set the manifold up along the length of the pit. Remember, you want the length of your pit to match the length of your manifold. So, if your manifold is 30 ft long, then your burn pit should also be 30 ft long.
Now you’re ready to burn! Add some debris and start a small fire, then turn on the air curtain incinerator. You want the debris to burn well for a few minutes (typically 10-30 minutes, depending on your debris) before turning it on. Once the air curtain is running and debris is burning, you can feed your fire with more debris. Be careful not to smother the flame with too much debris – it could cause the fire to go out. Feed it moderately and gradually to ensure a steady and efficient fire.
How Can I Get A Burn Permit to Use A Trench Burner?
You may need to obtain a burn permit in order to use an air curtain burner in your area. Please click the button to reach our info on burn permits.