What
is the importance of drum speed to the process?
All
Aeromaster turners offer variable drum speeds in the 150-300 rpm
range. Some composting paradigms call for 650 rpm or faster drum
speeds. We believe a variable drum speed in the lower range
offers a spectrum of benefits:
- Decomposition
of varying feedstocks may
benefit from specific rpm.
- Differing
time frames (number of days along) during the composting cycle
may suggest differing speeds.
- Equipment
does not make compost, microbes
do. The optimum drum speed and tine shape can provide
the ideal environment for beneficial microbes to flourish.
- Drum speed
and tine shape should lift, blend, and aerate
compost feedstocks rather than cut, shred, and pulverize.
- High drum
speeds retard, rather than accelerate, the composting process.
- Aggregation
for crumb structure and humus
development are limited when high drum speeds or a pulverizing
approach are used.
- A perfect
turn should move center materials to the perimeter and perimeter
materials to the center of the windrow.
Aeromaster turners do this rather than bouncing them off a hood
or curtain.
- A perfect
turn should get oxygen into the windrow and most carbon
dioxide out. Respiration tests in front of and behind
an Aeromaster turner will demonstrate the quality of this exchange.
- Lower drum
speeds reduce maintenance costs as stress is
reduced throughout the turner.
- Safety
is enhanced as the risk of projectiles flying from the
pile is largely eliminated.
 As
always, if a company or operator wishes to compare the quality of
our equipment or the ACS process, we simply ask them to submit finished
compost samples for the broadest array of tests to examine the quality
of the finished product for its soil and plant benefits. We are
happy to evaluate similar feedstocks under their current system/equipment
paradigm with the Midwest Bio-Systems/Advanced
Composting System approach to see which best succeeded.
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How
durable is the Aeromaster?
In
February of 2002 our office received a call from a composter who
said he needed to make a repair on his PT-120.
He'd had his turner for seven years and this was its
first breakdown.
Aeromaster
turners have been built to last. In fact, they have been described
as "overbuilt." This is important because decomposing
feedstocks do not wait for the operator's convenience. When
they need aeration, they need it today.
Grover
Landscaping in Modesto, California has described their SP-155 (since
replaced by the larger SP-170
self propelled turner) as "virtually indestructible."
They are especially pleased that they never need worry about becoming
stuck in wet ground. They say their Aeromaster has "exceeded
all our expectations."
Per
hour operating and maintenance costs for the self-propelled turner
have been demonstrated to be less than one-half the industry
standard. A combination of building durability into the
equipment along with a different composting paradigm make this possible.
What
are the advantages of a retractable drum?
Firstly,
at any point in the composting process the operator can stop,
raise the drum, and walk into the middle of a row to examine
the windrow  profile.
Such an examination reveals the extent of mixing and blending of
feedstocks, windrow stratification, the presence of molds, and the
extent of feedstock decomposition.
See
video of retractable drum here
>>
Also, if after beginning turning, the operator discovers the row
is too wet, he can cease immediately and drive
on rather than needing to complete the row or use a loader and shovels
to dig himself out.
Finally,
the drum can be locked in place for transportation
from one site to another.
What
are the tractor requirements for an Aeromaster pull-type turner?
Horsepower:
Generally, 80-100 for model
PT-120 and 90-120 for model
PT-130. However, lower or higher horsepower may be suitable
depending on your feedstocks, additional demands on the tractor
(i.e. loader attachment) and site conditions. For assistance in
determining tractor horsepower requirements for your Aeromaster
turner, contact your local Midwest Bio-Systems
representative.
540
PTO
Two
remote hydraulic outlets
Creeper
gear or hydrostatic drive
The
tractor needs to travel slowly at a range of 20-50 feet
per minute (.2 mph at rated PTO speed), depending on the stage of
the composting cycle.
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