radial aerated static pile

The success of any ASP system depends on how well you build your pile. GMT’s Radial ASP (rASP) system is designed to build the perfect pile by combining state of the art computer controlled telescoping conveyors with high capacity grinders. The telescoping conveyor places material from the grinder or mixer directly onto the ASP aerated pad reducing expensive loader and operator time. Using a loading conveyor avoids the compaction that happens when handling compost with a loader and the optional high energy flail breaks up clumps and increases porosity. The conveyor can also automatically rewet the compost pad with irrigation sprayers to maintain optimal compost conditions. The Radial system takes ASP composting from “one-touch” to a “NO TOUCH” processing.

One of the challenges with ASP systems is the application of the insulating Bio-Cover layer (6-12” layer of woody material) once the pile is built. The Bio-Cover layer significantly reduces odors and VOC’s and inhibits vectors like birds and flies. The automated conveyor system is programmed to accurately place the Bio-Cover layer to a specific depth and quickly cover a pile.

Radial Aerated Static Piles (rASP) are a simple and efficient way to compost challenging feedstocks like food waste, biosolids, and manures. rASP’s are simple because they compost faster and require less labor. rASP systems fit on a significantly smaller footprint than turned windrows. Smaller footprints result in reduced land costs, smaller leachate ponds and reduced pavement or concrete surfaces.

Pipes distributing air under the compost piles can be either above or below the working surface. There are significant
savings for pipe handling labor and repair costs if the piping is put below grade.

Above grade pipes work on existing paved or dirt sites.
Below grade piping is done by trenching existing paved sites or placing pipes below any new pavement.
GMT below grade aeration systems can last over 25 years without replacing pipes, nozzles or dampers.

POSITIVE, NEGATIVE AND REVERSING AERATION

Positive air allows for smaller blowers, less leachate generation and does not require biofilters. This feature is adequate for most feedstocks.

Negative air allows for complete capture and treatment of the air coming out of the piles, which is then treated using biofilters.
Reversing systems use both positive and negative aeration which reduce temperature gradients, water losses, and speed up the composting process significantly.

A key design decision in an ASP is the size and number of zones for aeration control and the division of the pile into discrete batches. The zone size depends on how much waste you want to compost every day and how long it will take to accumulate a batch. Partition walls function to divide compost into discrete batches. Mass beds, or trapezoidal piles have no dividing walls and therefore have less batch delineation but reduce the cost of construction. Ideally, a push wall is provided along the back of the ASP pad to allow a loader to collect and move material while protecting aeration equipment.

Storm water management is a critical part of facility design. Many states require impermeable surfaces for the active compost process. All the water collected on the pad must be collected in a stormwater pond and treated. ASP systems reduce the amount of impermeable surface by 50% or more over windrow systems. This adds up to significant savings in construction costs and leachate disposal. GMT will design your facility to minimize the size of your pad and stormwater collection system.

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