USDA Testing New Dry Air Precooler for Sweet Corn
Circulating dry, cold air
through thoroughly wetted sweet
corn not only produces cooling
rates comparable to those now
commercially obtained, but also
offers potential conservation and
economic advantages.
Consumers demand sweetness,
tenderness, and succulence in
their sweet corn. These qualities
depend directly upon the
postharvest temperature of the
corn, making precooling one of
the most important postharvest
conditioning treatments.
Hydrocooling, by far the most
popular precooling method,
requires large quantities of water
and has great potential for the
rapid spread of decay-producing
micro-organisms. Air and
vacuum precooling, two other
popular commercial methods,
are time-consuming and ex
pensive.
Reynolds
& Yellot
COMPANY INC.
REISTERSTOWN,
MARYLAND
833-1840 >
Builders Since 1953 /
FIELD CORN GETS TO THE
P. L. ROHRER & BRO. f INC.
SMOKETOWN, PA.
Arthur H. Bennett, an
agricultural engineer with
USDA’s Agricultural Research
Service, and engineering
technician James H. Adams,
Athens, Ga., are evaluating the
effectiveness of a precooling
method that offers the speed of
hydrocooling and the cleanliness
of air precooling. This method not
only uses much less water than
hydrocooling, but recycles the
water. It does not dry the com or
cost as much as vacuum cooling.
The ARS precooler utilizes
principles of simultaneous mass
heat transfer at air-to-surface
interfaces by passing air through
wetted corn packed in a
wirebound crate.
The test unit is designed to
provide a wide range of airflow
rates at various saturation and
dry bulb temperatures.
Saturation temperature for a
Pole-type
Farm •
Buildings
BANVEL Herbicide
POST-EMERGENCE
BROADLEAF WEED PROBLEM
given mass of air is that tem
perature at which the air can
neither absorb nor precipitate
any more water vapor. The
temperature of the air without
consideration of humidity is the
dry bulb temperature. Wet bulb
temperature includes the effects
of humidity which can cause
lower temperature readings.
Crates of corn are heated to 80
degrees F. and thoroughly wetted
before being placed into the
precooling unit. Space between
test walls and the- crate are
sealed to force maximum contact
of air with each ear surface.
Air leaves a cooling coil at a
saturation temperature with a
corresponding moisture content,
then passes through a fan and
over heaters where the dry bulb
temperature is raised to a
desired level while moisture
content remains constant. Since
the original equilibrium point
(wet bulb, dry bulb, and dew
point or saturation temperature)
has been altered with no
corresponding change in
mositure content, the air can now
absorb more water vapor. To
prevent frosting of the corn
surfaces, wet bulb temperature is
maintained at 32 degrees F.
As the air passes through the
spores around the wetted corn, it
absorbs heat through convection
and through evaporation of water
off the corn’s surface. The air is
<** % a
* 4*
DISTRIBUTED BY
then returned through the coil
where it is recooled and
dehumidified to the original
saturation temperature and
moisture content.
Mass rates of airflow tested
were 900, 1,800, 2,000 and 2,700
pounds per hour, each at initial
air dry bulb temperatures of 35.0,
37.5, 40.0 and 42.5 degrees F.,
respectively. Cooling rates are
affected by airflow but not, ap
parently, by dry bulb tem
perature.
The operation is relatively
quick and thorough. No drying
effect has been noticed at the end
of each run. The weight of a test
crate is always greater after
Arthur B. Morgan, 62 Bowman
Rd., Lancaster, has been named
to the Board of Directors of
Victor F. Weaver Inc. and sub
sidiaries it was announced today.
A native of Irwin, Pa. Morgan
moved to Lancaster in 1935 to
work for New Holland Machine
Co. While at New Holland he held
various sales and marketing
positions, the last of which was
director of dealer relations, prior
to his retirement several years
ago.
APPLICATION IN
ROOT OF YOUR TOUGH
Your corn crop is well along. But tough, deep
rooted weeds threaten to take over. The earlier
you spray Banvel, the better, preferably before
hot, humid weather.
Even though you spray over the tops of corn,
normally no brittleness develops. If you see
velvetleaf or pigweed, a lower rate of Banvel mixed
with 2,4-D will give most effective control.
Banvel works! For one simple reason. Banvel
translocates. Absorbed by leaves, stems, roots,
Banvel moves with plant fluids from leaf tip to
root tip. Destroys as it goes. So, no regrowth.
In permanent pasture, Banvel gives you easy
control of more than 40 of the most common
weeds, including wild garlic, weed brush
and weed trees.
Cost of Banvel? Up to $1.90 per acre broadcast
in corn. Ask your dealer or custom sprayer for
full information.
BANVEL® from
VELSICOL
VELSICOL CHEMICAL CORPORATION
341 East Ohio Street • Chicago, Illinois 60611
* *
Lancaster Farming, Saturday, July 1,1972
Weaver Names
New Director
PH: 397-3539
each test run than it was initially,
and the corn always has a fresh
appearance. In some instances,
air dry bulb temperature is lower
upon leaving the corn than when
entering, indicating that most of
the evaporative cooling effect
produced by water vapor tran
sfer is cooling the air rather than
the corn. Subsequent tests,
carried out in collaboration with
industrial engineer Fred E.
Henry, Gainesville, Fla., show
that comparable cooling rates
are achieved by using saturated
air (air that has not been dried) at
corresponding dry bulb tem
peratures and mass rates of
airflow.
Morgan is the owner of the
Cloister County Store in Ephrata,
as well as vice-president and
treasurer of the Anush Village,
and Lancaster Lincoln and
Mercury. He currently serves on
the board of directors of the
Lancaster General Hospital, the
Enterprise Telephone Co., and
the New Holland Farmers Bank.
An active participant in
community affairs, Morgan is
married to the former Verna
Heller of Lancaster.
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