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Paratherm's Laundry Industry Page*
Hot Oil Systems for Laundries
Gaining in popularity, thermal oil systems used to heat flatwork ironers offer greater productivity per unit floor space. System corro¬sion, condensate return and steam trap maintenance are eliminated. There is no water treatment or discharge problem, and operating costs are substantially reduced through system efficiencies. And, in most areas of the country there is no need for expensive licensed operating engineers.
Productivity
While steam systems generally operate to 350°F, thermal oil systems can easily provide 450°F – with the pump discharge providing only enough pressure to overcome pipe friction. To compare, an oil heated 3-chest ironer with parallel flow can provide about the same output as a 5-chest steam-heated unit.
And because of the low pressures common in thermal oil systems, the chests can be fabricated of steel rather than the cast-iron required for steam systems. Not only is this a cost savings, but heat transfer is improved with steel, and the lower number of chests saves valuable floor space.
Maintenance
With steam systems, corrosion is a foregone conclusion. The goal is to reduce corrosion as much as possible, principally through water treatment – which is expensive and time consuming. And because of corrosion, traps and other components must be constantly maintained.
Thermal oils will not corrode the materials commonly used in laundry systems. In fact, oils pro-vide a protective coating to metals in the system and offer high lubricity to moving parts. And barring leaks or spills, no make-up is necessary.
Environmental Concerns
The water used in a steam system must be treated to reduce
corrosion and increase lubricity, among other requirements. The chemicals used, in some cases, are considered regulated and/or hazardous wastes. Blowdown and system leaks must be closely monitored, and the system’s water cannot be allowed to enter floor drains or flow into waterways. There is no blowdown in thermal oil systems. And spills can be handled using the same
procedures used for releases
of lubricating oils.
Operating Costs
Steam systems lose energy
through flash, blowdown and de-aeration cycles. Thermal oil systems operating at higher temperatures use less fuel because these losses are eliminated.
Licensed Operating Engineers
A steam system operating at 350°F, generates 120 psig. At these pressures, most states re-quire a licensed operating engineer be employed to supervise the system. Thermal oil systems operate at pressures dictated by the discharge of the pump, static head of the expansion tank and vapor pressure of the fluid (usually well below atmospheric).
If high pressure steam is required, the laundry can specify the use of an unfired, hot oil heated shell and tube steam generator. Thermal fluid heat exchanges can produce hot water and hot air as well. These units have proven extremely reliable. And, in hot water exchangers, fouling tends to happen much more slowly than fired steam, principally due to the low heat flux.
System Economics
A thermal oil heater costs more than a steam boiler. A 3 or 4-chest oil-heated ironer, however, costs less than a 5 or 6-chest steam heated unit. With thermal oil, additional savings are generated in the elimination of deaeration, blow down and chemicals used to treat the water, not to mention low maintenance, smooth operation, and tight temperature control.
The biggest savings involve the elimination of the licensed operating engineer. If local regulations permit this with thermal oil systems (as many do), the balance swings heavily in favor of the oil system.
We strongly suggest you consult a competent engineering consultant for a thorough evaluation of your requirements and a balanced approach to the decision for steam or thermal oil. Call us toll-free with questions.
Or, visit us at The Clean Show.
Notes:
- We strongly recommend you consider an expansion tank equipped with a cold-seal tank, or inert gas blanketing. These can largely eliminate oxidation of the heat transfer fluid. One of the most insidious types of fluid degradation, oxidation, is discussed more thoroughly in our data sheet entitled “Oxidation in Heat Transfer Fluids ”.
- In selecting a heat transfer fluid for use in laundries, these areas should be given priority:
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Flash and fire points. The Paratherm HE fluid has a flash point of 440°F, and a fire point of 500°F, higher than the operating termperature of the ironer.
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Low vapor pressure. Vapor pressure of the HE fluid is among the lowest of any fluid available
- Non-toxicity. The HE fluid is non-toxic and has passed stringent Bioassay, while many heat transfer fluids are considered hazardous and/or regulated waste.
- Low pumping horsepower requirement. The HE fluid requires among the lowest pump horsepower of any fluid available.
- Underwriters Laboratories approval. Paratherm’s HE fluid is U.L. approved: MH1 7163 (N).
- Broad industry acceptance. The HE fluid is currently used in a wide range of hotel, institutional and central laundries and is fuly approved by leading manufacturers of laundry equipment.
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Paratherm Corporation is an associate member of NAILM
The Engineers at Paratherm Corporation know thermal processing systems and
applications as well as they know their fluids. Successful laundry facility managers and maintainers are getting the most out of Paratherm and its
superior products and engineering support.
Want a further taste of Paratherm's expertise? Look
at the menu bar on the right of this page, and click on the TipSheet™
link. Here you'll find brief technical notes about systems.
TipSheets cover system safety, efficiency, contamination, tuning and trouble-shooting,
starting up, shutting down, and more. Like what you see? Sign up
and you'll get these quick technical briefs every month or so via email—or RSS.
Paratherm heat transfer oils are stocked in 6 locations around North America (and 5 more around the world) so you can get them fast. Click on Availability to see where.
For comprehensive and accessible information, organized
for quick and handy reference, click on Heat
Transfer Fluids or System
Cleaners at the top of the navigation bar on the right. Don't
forget the other links too! Although heat transfer fluids and cleaners are what
we ship to you, services are what we do for you. All day,
everyday. Design assistance, thermal fluid analysis, applications support,
preventive maintenance, and fast, attentive response to orders and other needs.
Paratherm has been developing new heat transfer fluid products
since 1988—products that continue to improve the efficiency of thermal processing
applications and product quality . Paratherm customers have learned to count
on the safety and reliability of these safe, non-toxic, non-fouling fluids.
New stocking and shipping locations mean customers get the
products they require quickly. And Paratherm's commitment to applications and
system support means they get the answers they need even more quickly.
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