Baking & Snack - September 2019 - 80

MIXING

safety, quality assurance, continuous improvement and
lean manufacturing initiatives to higher levels.

Heat of the moment
For example, take consistent dough temperature and,
specifically, controlling the amount of heat transfer
that occurs during the mixing process to ensure uniform production and high yields. Mixers need a jacket
design that doesn't generate hot spots or thermal variations, noted Rick Kesig, business unit technical advisor,
Peerless Food Equipment. "Using horizontal cooling
channels on a horizontal mixer achieves this uniform
cooling heat transfer while also increasing the stiffness
and strength of the bowl and jacket," he said. "An inherently higher moment of inertia in the horizontal jacket
design accomplishes both of these objectives."
Mr. Kesig added that a Peerless horizontal flow-style
jacket directs the coldest glycol directly to the bowl area
with the greatest dough contact and kneading forces.
"The temperature is maintained across the full length of
the bowl sheet, thus eliminating any thermal gradients
to optimize cooling," he explained.
Marc Ferree, sales engineer, Shaffer, a Bundy Baking
Solution, pointed out that bowl jackets have been
around "forever," and refrigerated agitators have been in
use for more than a decade. "However, the overall details of design of the jacket and agitator continue to be
reviewed to make sure they offer maximum strength and
dough cooling," he said. "The cooling of dough during
the mix cycle is most critical for downstream machining
of dough and preventing early fermentation."
Specifically, Shaffer's triple-roller bar mixers with a

Mixers come with multiple
kneading chamber designs
for various products.
VMI

80 Baking & Snack September 2019 / www.bakingandsnack.com

refrigerated agitator and VerTech cooling jacket provide enhanced dough temperature control. The new
VerTech design is engineered to distribute dough force
over a larger area and results in 75% reduction of stress
on channel material and 63% reduction of stress on weld
joints. Moreover, Mr. Ferree said, the energy-efficient
design provides the same heat transfer with up to 46%
reduction in pressure over older designs, resulting in
less energy to operate the glycol system. "It continues to
surpass expectations on cooling efficiency, bowl strength
and longevity," he pointed out.
Based on double-tool technology, the Kneadster by
VMI comes with larger tool diameter and synchronized
rotation that prevents rises in dough temperatures, promotes stretching and aeration, and creates the necessary shearing action to properly develop from soft to
stiff doughs. "The mixer's efficient integration of the
ingredients decreases the total mixing time by about
30% and limits the increase of the final dough temperature by around 50% compared to a conventional
spiral mixer," said Terry Bartsch, president and CEO,
VMI North America.
One way to avoid heat transfer is not to create it in
the first place. "Our whole mantra is, 'If you properly
configure the mixing bowl - the bowl shape, the RPM
of the agitator and the proper roller bar diameter and
roller bar clearances - you don't make the dough hot,' "
Mr. Morabito said.
Topos adjusts its mixers for dough absorption to
achieve the proper kneading effect for soft doughs,
which require higher RPM and longer mix times than
stiffer doughs. A digital operator interface allows bakers

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Baking & Snack - September 2019

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