heat transfer fluids continue to occupy an important place
in liquid heat transfer systems. Synthetics are best specified
where natural fluids cannot function: at system temperatures
above 600°F, at very low temperatures and, if they
are able, in the vapor phase.
Here are some
of the reasons you might consider a heat transfer fluid
manufactured from natural feedstocks, like the MultiTherm
IG-4® non-fouling, non-toxic fluid.
The purchase cost of many synthetic fluids ranges from
slightly to substantially higher than the cost of the
MultiTherm® fluid. Handling and disposal add significantly
to this cost.
At medium temperatures synthetic fluids typically provide
equal-to-higher film coefficients than the MultiTherm®
fluid. However as temperatures begin to climb these differences
become considerably smaller - until at the high end of
the range, MultiTherm's coefficients exceed those of most
synthetics. (Higher film coefficients mean greater availability
of BTU's at the user surface.) The MultiTherm® fluid
is more efficient.
When properly specified and operated in well-designed
systems, all heat transfer fluids will provide good service
for reasonable periods of time. However, degradation caused
by oxidation, overheating and contamination will cut this
service dramatically. Due to its non-fouling characteristic,
the MultiTherm® fluid is considerably more forgiving.
It's service life is proven equal to or greater than the
Most synthetic fluids are moderately or significantly
toxic. In comparison, the MultiTherm® fluid is completely
non-toxic (it is certified food-grade).
Safety Data Sheets
for aromatic fluids indicate that small quantities of
benzene gas may form and concentrate in the expansion
tank when the fluid is severely overheated.
is most often the direct result of low flows at the heated
surface. Occurring at the fluid's film layer, overheating
can happen even at low or moderate fluid temperatures.
You'll notice little, if any, change in the fluid's bulk
If you are using
aromatic fluids, you should make sure the system's expansion
tank is vented to an area where the fumes cannot concentrate.
You should carefully
review the fluid's Material Safety Data Sheet (MSDS) for
toxicity information regarding respiratory, ingestion
and skin-contact. Skin dermatitis and respiratory problems
have been reported with virtually all synthetics. The
MultiTherm® fluid has no odor and has been reported
to actually soften the skin.
While no fluid should ever be permitted to enter the environment,
mishaps can and do occur. Hazardous or regulated waste
procedures must be followed in the clean-up and disposal
of most synthetic fluids.
same simple clean-up procedures for light lube oils can
be employed with releases of the MultiTherm® fluid.
And, used or contaminated MultiTherm® fluid can be
safely combined with spent lube oils and sent to the local
oil recycler (EPA, citation 57FR21524). This helps conserve
natural resources and precious landfill space. The MultiTherm®
fluid has also passed rigorous Bioassay with three species
(Rainbow trout, saltwater shrimp and freshwater shrimp).
Fouling has been observed with all synthetic fluids. This
fouling normally occurs as fluid flow drops at the heated
surfaces. Less heat is removed, the heat balance is upset
and film temperatures quickly soar. This high heat flux
overcomes the strength of the fluid's chemical bonds.
As they break, fine, amorphous "sooty" carbon
is formed. Much of this carbon immediately adheres to
the heated surfaces and bakes on, creating insulating
severe overheat conditions, the MultiTherm® fluid
evolves carbon granules that do not adhere. Instead, they
remain in suspension and are easily filtered out. This
is particularly important in electrically heated systems
where hard baked-on carbon deposits most often occur.
Even when operated within their normal temperature range
synthetic heat transfer fluids can produce a mild to heavy
odor. In contrast, the MultiTherm® fluid has none.
The MultiTherm® fluid has for years been successfully
used in a broad variety of demanding applications in the
processing of chemicals, food, pharmaceuticals, oils,
adhesives and petroleum. It provides precise, uniform
temperature control in process applications including
die casting, injection molding, curing, laminating, calendering,
drying , and printing - just to name a few.
fluid is approved, recommended and/or specified by a wide
range of original equipment manufacturers whose equipment
is used in these processes.
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