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As high-priced petroleum-based energy is
increasingly supplanted by alternative-source
electric, (nuclear, hydroelectric, solar, hydrogen,
wind,) high efficiency electric heating will
inevitably make petroleum-fired boilers obsolete.
Contemporary boilers are bulky, require
mechanical vigilance, demand physical isolation from
the processing floor and have a notoriously large
carbon footprint. Even in efficient processing
plants with excellent thermal recovery, only 20% of
the energy supplied as bulk fuel ultimately becomes
food heat. Steam transfer losses account for much of
the remaining 80%. Processing facilities must often
use additional energy to remove waste heat.
Currently, liquefied petroleum gas (LPG) is the
preferred fuel source for steam boilers.
A therm of LPG is about 50% as expensive as a
therm-equivalent of peak-use electricity. The therm-equivalent
off-peak cost of LPG and electricity is
approximately equal. Therefore, a peak-use electric
heating alternative to steam heat must deliver 40%
of its energy as food heat to compete with the
prevailing boiler-heat model of thermal processing.
Using off-peak electric would provide further
operating economy.
Magnetic induction heating in contrast allows
high efficiency conversion between electricity and
food heat. Passive thermal diffusion transfers heat
between the inductively-heated tube bundle and the
food. In the present design, 80% of the electric
supply energy directly heats the tube bundle with
subsequent transfer to the food. The remaining 20%
appears as heat in the induction coil and
electronics of the induction unit. A water cooling
system captures this heat and uses it to preheat
product entering the heating stage.
Preliminary tests indicate that 95% of the
electric supply energy can be captured as food heat
when magnetic induction is coupled with energy
recovery from the coil and electronics. A commercial
system operating as this efficiency would observe an
immediate 2 to 5 fold energy savings and could
potentially reduce its carbon footprint to 0.
It is believed that replacement of steam boilers
with induction heat would reduce energy loss with
concomitant increases in energy savings. Additional
advantages versus steam are sturdiness, low-price,
portability, ease of cleaning, training ease,
amenable to computer control, flexible interchange
of tube bundles designed for various viscosity
products and space savings. The unit also makes
inroads into developing processing technologies for
the inevitable all-electric energy future.
George Sadler is the Founder
of PROVE IT, LLC (Packaging Regulation,
Optimization, Validation and Education for
Innovative Technologies) which develops and achieves
FDA validation for innovative packaging and
processing technologies. He has 20 years of academic
experience dealing with technical and regulatory
issues related to food packaging. Dr. Sadler
received his PhD from Purdue University and has held
faculty positions at University of Florida and
Illinois Institute of Technology. He has specialized
in technical and regulatory issues involving polymer
recycling, irradiation of food contact polymers, and
the use of migration models for assessing dietary
exposure for indirect food additive submissions to
FDA. His research interests include active and
intelligent packaging, experimental approaches for
assessing migration, and the impact of novel food
processing technologies on packaging performance.
For article feedback contact George at
gsadler@proveitllc.com.
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