GOVERNMENT SERVICE REGULATIONS REGULATIONS This section of our Web Site is designed to help regulatory authorities with understanding and developing rules for the operation of air curtain burners (ACB's). For underlying regulations and related data for regulatory compliance issues the links below should be helpful. 1. EPA Regulations (Current) Click Here 2. EPA Regulations, Proposed 2005 Rule Change Also: See Air Burners Comments Below Click Here 3. ACB Permit Information, Regulations and Rule Changes for Selected US States Click Here 4. Particulate Matter Reference Material and Related Data on the Disposal of Clean Wood Waste Click Here US-EPA Links of (2005) :   Comments by Air Burners, LLC to 2005 Proposed EPA Rule Changes (See EPA EDOCKET OAR-2003-0156 Title: "Standards of Performance for New Stationary Sources and Emission Guidelines for Existing Sources: Other Solid Waste Incineration Units") Link discontinued Comments submitted by Brian O' Connor, President, Air Burners LLC  02-Feb-2005  Public Comment  OR Click Here for an Archived Copy on Air Burners' Server   Why Air Curtain Burners? S-116 - Lake Tahoe, California, 2001 (State of California unit shown In full operation)   Air Curtain Burners (ACB's) provide an environmentally friendly alternative to open burning.  Simply stated air curtain burning is the most environmentally friendly way to dispose of wood waste.  It is a natural process.  ACB’s rely strictly on airflow to enhance the fire and reduce the emissions.  Open burning is nature’s way of grooming the forests and generating new growth.  This process has been managing the world’s forests for millions of years.  Our objection to open burning is its inefficiency.  Poor combustion results in high particulate release and high carbon dioxide. When a land clearer piles wood waste for open burning the poor combustion is due to the natural tendency of a fire to self insulate with ash build up.  Unless the fire is continually agitated either manually or by high winds then the ash builds up and reduces oxygen flow to the fire.  Reduced oxygen causes reduced heat; reduced heat allows more particles to escape unburned.  We call it smoke. The Air Burners ACB using airflow traps the unburned smoke under the air curtain causing it to re-burn down to an almost gaseous state.  The air coming from the patented manifolds delivers the controlling air curtain then as the air distributes off the wall opposite the manifold it provides the manual agitation to keep the ash from forming on the burning wood.  The ash drops to the bottom exposing the coals to burn hotter and cleaner.  During independent testing of our machines temperatures in excess of 2000 degrees Fahrenheit have been recorded in the area above the fire but below the air curtain.  Does it work?  There are many studies and evaluations you can review TECHNICAL REPORTS  to verify that yes it does work. What about chippers or “cut and drop” Certainly those are both methods of wood waste disposal that have been employed.  Both have significant environmental impacts.  Wood chippers were designed to allow the land clearer to get more product into his truck.  So instead of 10 trips to the landfill he would only have to make, say 5 or 6.   The environmental impact is an increase of mass to our already full landfills.  Additionally as wood waste decays, it releases gases such as methane and carbon monoxide.  Significantly more harmful gas is released over the lengthy period of decay than is released by burning.  In Europe this problem is more critical as the landfills are more crowded than in North America.  That is why legislation has been passed banning wood waste to landfills by 2006.  In North America we are trying to recycle some wood waste and we, of course, support those efforts, but the markets for wood chips on our gardens or in power plants only accounts for about ten percent of our waste stream. S-217 - Full Operation  (Demo for State of Florida DEP & Forestry Service) In the forests the tactic of “cut and drop” is sometimes employed and where it works from both and environmental and ecological stand point then of course it should continue.  But in most cases the problems of cut and drop out-way the advantages.  First there is the obvious increase in potential fire fuels.  Second the forest ecosystem is unbalanced, as most of these “cuttings” would not have dropped naturally.  Therefore the ecosystem changes in accordance with changes to the forest floor.  Once the additional animals, insects, bacteria and fungi have used up these additional cuttings then where do they go?  New growth? As in most situations there is more than one answer and every answer is a compromise.  Why use an Air Burners LLC ACB? • Because it is one method of reducing wood waste in a manner close to the natural process. • It provides an element of control and safety in comparison to open burning. • It does not add to the already considerable burden of our landfills. What are the differences between Trench Burners and Fire Box Burners? The Refractory Walled Fire Box Burners provide more control, they are safer to operate and they generally will burn cleaner.  Having said all that, you should know that we invented and patented the first Trench Burner.  So don’t we like them any more?  The answer is "Yes", we still like and promote Trench Burners, but, as you would guess, there are plusses and minuses to each machine. The FIRE BOX Burners are fully self-contained; there is no guesswork as to how big or wide the burning area should be.  These units are above ground, so water table, rocks and roots are not a problem.  Also being above ground, allows for easier ash removal.  About the only thing an operator can get wrong, is how high to fill the box.  The real minus for these units are their size.  Our smallest unit weighs over 20,000 lbs.  So dragging it around in soft soil can be difficult.  While our smaller boxes, the 100 and 200 series, will fit on a standard 102 inch wide flatbed trailer, our 300 series is an oversized load for most roads.  So the logistics are a bit more complicated than towing a Trench Burner. The TRENCH BURNER can be easily towed behind a pick-up truck to the job site.  These units will handle more uneven terrain than the Fire Boxes and can be mobilized quickly.  The trench allows the operator very good visibility of the burn, and loading the pit does not require raising the materials up over the wall.  The real minus for the trench burner is in the trench.  Will the operator dig the trench correctly?  If he doesn’t, then the efficiency of the machine goes down.  That means emissions increase and thru-put drops.  If the operator doesn’t dig the trench deep enough (or at all), then the whole principle of the air curtain is lost. What is the best way to regulate? In our opinion, the absolute best way to regulate is by results.  Opacity: If the opacity is too high, it is not being operated correctly. The litmus test is opacity.  If the unit is generating smoke in excess of 10 or 20 percent (after a 30 minute or one hour start-up period), then it is not being operated correctly.  Some regulators have latched on to airflow citing manifold velocities and mass flows.  These regulations are unfortunately flawed.  Refer to our PRINCIPLE OF OPERATION for an understanding of the basic operating principles.  The problem with specifying flow is, that you can create a good air curtain by using either high velocity and low mass flow or by using high mass flow and low velocity.  This is some of the “black art” that goes into the engineering of an air curtain.  Additionally, there is a limit as to how much airflow you can have for a particular size trench or box.  Too much air and you destroy the curtain by over pressurizing the fire area and you over-agitate the ash causing a high release of embers and fly ash.  If you pick one manufacturer’s airflow specs you may preclude a better development and possibly a better machine later on.  As an example, our airflow specs changed significantly just four years ago, and they are about to change again as new technology has become available. Ultimately, our goals are to provide you the best performing machine, the best price and the best quality.  Our suggestion is “measure the results, not the machine.” What should the operation look like? With the machine set up, the actual burning operations are almost identical for the Fire Box or Trench Burner.  • Load burn pit with finer materials easily burned material such, as smaller branches, small logs, etc. • Load the pit to approximately half full. • Pour an approved accelerant, such as Diesel fuel on the fine material. • Load some heavier logs to just under the manifold level. • Light the accelerant, light from the bottom, as you want the fire to burn up, not down.   Once the fire has fully engaged (usually 15-20 minutes) turn the air on lowest setting. • Watch that you don’t blow the fire out with too much air. "More air" is not necessarily better, often actually worse. • As the fire progresses, increase the air to normal operating RPM's. • For the first hour, load very slowly to allow the fire to burn through, overloading smothers the fire, traps unburned material low in the pit, increases smoke and slows thru-put. • The amount to be loaded will increase with each hour of burn, as the coal base builds and gets hotter.  The key to high thru-put is “Not to get ahead of the fire.” • After your last load at the end of the work day, allow the fire to burn down decreasing the air as smoke begins to appear. How long should they burn? Our machines are designed to run for approximately 20 hours before they need refueling and the pit emptied.  The longer the run, the more efficient the burn, the lower the emissions.  The efficiency starts to drop once the ash pile reaches approximately 1/4 to 1/3 the depth of the pit or approximately 3 feet. Should the fire be completely out each night? It is a safety question.  Barring extremely high winds, there is very little chance of any embers escaping from either the trench or fire box.  If there is a chance of people or animals falling into or climbing up on the pit or firebox, then the fire should be appropriately covered with dirt.  If the fire danger is high, then the burn firebox or pit should be covered. Our ember screen has been designed for all our firebox models to be placed over the top at the end of the work day to help prevent any embers from escaping while the units are unattended, typically at night. Previous Page Top of Page