Sep 03, 2002

360° Discharge Removes Bottleneck In Screening Liquid Biological Fertilizer

Products In Action

AgriEnergy Resources boosted throughput of a circular
vibratory separator by 200-300 percent by employing a 360° discharge
Kascade® deck that eliminated a restrictive buildup of rope-like sludge
around the screen circumference.

In one hour, the 60-in. diameter separator now processes
9,000 gallons of liquid biological fertilizer versus 3,000 to 4,500 gallons
previously. AgriEnergy saves nine worker-hours of downtime per week by
minimizing the need to stop the separator, remove the screen deck, wash off
sludge buildup, replace the screen and re-start the process. Labor reductions
and productivity increases paid for the added equipment in less than one year.

To increase production of liquid biological fertilizer by 30
percent, AgriEnergy installed the circular vibratory separator (its second) fed
by a 3,000-gallon and a new 6,000-gallon mixing tank, but the rope-like buildup
of sludge restricted screener capacity by 20 to 30 percent.

In efforts to eliminate sludge buildup, the company added
hollow plastic anti-blinding rings intended to dislodge sand and large
particles from screen apertures and promote product flow over the entire screen
surface, but with unsatisfactory results.

AgriEnergy also considered adding another 48-in. diameter
circular vibratory separator, but Kason Corporation's representative
Windum Process Equipment in Saint Charles, Illinois, recommended the less
costly Kascade discharge frame alternative after successfully screening samples
of compost suspended in water in its laboratory. The supplier of the original
separator was unable to resolve the problem.

The deck discharges material 360° around the
screen's periphery, instead of through a discharge spout that exposes
only a fraction of the screen periphery through which the material must exit.
The Kascade deck reclaims 100 percent of the screen surface area and reduces
screen wear.

"The Kascade deck knocks off the ring of material
right away," said Merlin Nussbaum, fertilizer production manager.

Compost suspended in water, stored in 3,000-gallon and
6,000-gallon mixing tanks, is pumped at 200 gpm to the circular vibratory
screener that separates it using a 120 mesh screen. Sludge exiting the
discharge port beneath the Kascade deck falls into a dumpster, while the liquid
extract containing clay and other particles smaller than 120 mesh, flows from a
discharge spout to a liquid holding tank. It is then pumped to one of thirteen
3,000-gallon storage tanks in which the particles settle out for five days.

For the first of two product applications, liquid extract
containing the 120-mesh product is pumped directly to tanker trucks that
deliver it to farms where it is applied by tractor-pulled sprayers or custom
floater spreaders.

For applications requiring 200-mesh particle sizes, 120-mesh
extract drawn from the tanks, runs through the original 48-in. diameter, 200
mesh screener, and is pumped to tanker trucks. The fine liquid fertilizer is
used for drip tape irrigation, which requires the solution to flow through
small diameter holes that coarser particles would clog.

Previously, AgriEnergy Resources processed both the 120 mesh
and 200 mesh products with the original circular separator, which had a 50 mesh
screen on the top deck and a 120 mesh screen below. Operators changed the
bottom screen between 120 and 200 mesh sizes and rearranged hoses between the
settling tanks and separator, incurring nine additional hours of downtime
weekly, and limiting production to 3,000 gallons per day.

Adding the second mixer and second circular vibratory
separator with Kascade deck enabled the company to process 9,000 gallons per

?The deck easily handles the increased production in
less time,?said Nussbaum. "If anyone's removing solids from
liquid, this is the way to do it."

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