Materials in food processing plants must meet high standards for sanitation and durability. Even periodic wash downs on noncontact food-cooking equipment like rotary sterilizers will cause traditional insulation to fail from water contact.
Insulation in general is so sensitive to moisture that even 20 percent water vapor content causes almost complete loss of thermal value. Add the ability to shelter pests, germs and mold, and it is easy to understand why you see little traditional insulation used on plant cooking equipment.
However, one type of insulation has performed for several years on rotary sterilizers and steam lines and equipment. It's also used for condensation control on cold surfaces and to reduce heat loading on building envelopes. This insulation is ceramic-loaded coating, and it is as easy to apply as paint.
Ceramic-loaded coatings were originally used for personnel protection on steam lines and valves. Over the past 2-3 years, this acrylic latex-based insulation coating has also proven its ability to save 25 percent on steam generation based on equipment manufacturers and third-party testing and evaluation.
And while methods were developed to evaluate energy savings on hot equipment, food processors also qualified their energy savings applications for PG&E energy rebates. The net result is sanitary insulation with energy savings performance that provides an ROI time frame of 1-2 years.
The working components in this insulation material are tiny, hollow glass beads bound with acrylic latex coating. This single-part coating formula also allows application with commercial-type, airless spray equipment.
Considered a radiant barrier, ceramic insulation coatings use their high-density layers of ceramic particles to block heat transfer. Another good example on how thin coatings block heat transfer are the thin oxide layers of Low-E windows that block infrared radiation from the sun's rays.
Years of use by companies have proven this insulation material meets requirements for periodic sanitation on cooking equipment and surfaces. Washing with caustic solutions and pressure-wash rinse is the procedure for sanitation. For the same reason, extra care is used when pressure washing the side of your house, it's important to exercise some restraint.
Companies that have applied this type of coating on retort or rotary sterilizers are BumbleBee, Campbell's Soup, ConAgra Foods, Del Monte and Stanislaus Foods. JBT Food Tech uses this insulation on cooking equipment supplied to customers around the world.
Stopping condensation on interior cold surfaces and reducing solar-based heat loading by 10-15 degrees F on buildings has been tested and proven by Schrader Mechanical of Valley Springs at Stemilt Fruit's Chinchiolo plant.
Performance has been verified by multiple companies. Del Monte Foods tested ceramic insulation coating using side-by-side steam lines — one coated with ceramic and one uncoated — leading to a rotary sterilizer.
Steam traps were attached to the front and back of the lines during the time steam heated a rotary sterilizer to service temperature in the 210-degree range. By running the steam condensate through cooling coils, water was collected and volumes compared. The net difference between the two lines was 25 percent, showing the additional energy required to heat condensate up to steam.
JBT Food Tech's internal testing of steam use on rotary sterilizers has indicated a thermal efficiency of 28 percent. Using this type of efficiency value with typical gas and application costs yields an ROI from 1-4 years, subject to the type of food processed, operating season length and availability of energy rebates.
The good news is that solutions for energy efficiency are proving they can meet the needs for today's food plants. They are proving reliable in tough conditions and being recognized as providing the necessary ROI that businesses require.
