Posts tagged fluid analysis

What Makes Paratherm Different

How does Paratherm differ? We drew the differences in a 2-minute video — whiteboard style!

And, for those of you who prefer to read, skim, study, and/or critique the written word, here is the voice-over script…

videofrontThe beauty of closed-loop hot-oil technology is that it operates simply and uniformly with little of the maintenance intervention required by alternatives like steam or direct heat. But this low-maintenance characteristic of the technology may leave you in the dark about the operating condition of your application, or what to do when shut down — or slowdown — occurs. Paratherm focuses on keeping you involved in every aspect of the care of your system, from the fluid sale and initial fill, to fluid analysis, troubleshooting and preventive maintenance. Paratherm’s experts will help advise you in the selection of the right fluid for your unique circumstances, and their professional fluid analysis will help guide preventive and predictive maintenance to help improve the system’s operation—and extend its operating life. Unplanned downtime with your application can cost you thousands of dollars every hour that you’re not in production. Therefore, Paratherm utilizes a streamlined logistics flow for fast supply when you need an expedited response. We keep our fluids in stock at several locations throughout the country. When you send us an order, we’re typically able to ship it the same day. When issues with your hot-oil system arise, Paratherm’s Technical Services section is ready with probing questions, and then, troubleshooting tips to help get it working again. You can reach someone by phone for technical assistance or an emergency shipment at any time, including evenings and weekends. At Paratherm, thermal fluid is all that we do, so we have to be the best. For more information on our products and services, simply call or visit our website and fill out our online form.”

To receive a series of emails about Paratherm, and thermal fluid technology in general, visit the Learn About Paratherm page at About Paratherm.

Summer is System Maintenance Season

Summer means long, hot days, beach trips, barbecues, and plenty of celebrations. It also means days off and time away from work; at Paratherm, we often notice that this translates to downtime for our clients’ process-heating systems and a slow-down at their facilities.

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Fluid Analysis Kit

When things do slow down, it’s a good time to focus on maintaining and improving your heating system; it’s also critical to your quality and safety. In fact, fire safety professional groups and insurers say that fluid analysis is considered a best maintenance practice, while the NFPA and Industrial Insurance underwriters suggest a minimum of annual testing.

One of the best ways to perform regular maintenance and testing is through a comprehensive analysis. Using our fluid analysis kit—which simply entails sending us a sample—we can determine any early warnings about process and equipment problems, and catch something before it becomes a bigger concern. The analysis tests both acid number and viscosity, and determines whether the fluid can remain in use, or needs to be replaced. It also analyzes the condition of the components of the system itself—another invaluable, time- and money-saving tool.

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Hot Oil System Cleaner Dissolving Sludge

If you are having trouble keeping a process hot or getting the system up to running temperature, this could be an indication of fouling in the heater tubes. In this case, Paratherm liquid cleaner can be used to effectively dissolve deposits while the system is running, and will result in a cleaner, more reliable system.

Taking the short amount of time now to perform a fluid analysis and using the system cleaner will prove invaluable in the long run, ensuring safety and savings throughout the year. Then you can relax and enjoy those summer celebrations.

Sampling Part 2: Where and How

Where and how you take a thermal fluid sample can make all the difference in what the test results reveal.

Where a sample should be taken is simple – any location where there is flow and the temperature is above 180°F. A blowdown valve on the pump suction strainer housing is a good bet since that’s where you’ll find the lowest pressure and temperature in most systems.  Piping drain valves will work as long as you purge several containers worth of fluid before taking the sample. Expansion tank or thermal buffer tank drain valves are tempting as a sample location because they are (usually) cool and (mostly) accessible. Don’t do it. For a long list of reasons, it’s almost the worst place to take a sample, just above scooping it off the floor near the pump.

Shows jar, tubing, safety-gloved hands, heat transfer fluid sampling

Taking the Hot Oil Sample

How to take a sample is not quite as simple. Why?  Because improper sampling practices can actually alter the physical characteristics of the sample that will be measured.

Ideally, a sample should be taken directly into a glass sample jar so any contamination or carbon in the fluid is easy to measure. The problem with glass is that it can shatter if the sample is taken too hot (above 250°F).  So if the next heater shutdown isn’t scheduled until the Phillies win the pennant, install 18-24” of ¼” copper tubing on the sample port and bend a loop or two through a bucket of water. This will knock the sample temperature down the couple hundred degrees needed to keep the glass from breaking.  Or take the sample in a clean metal can with a screw top and send that in (just remember to label it with the system name and date).  Do not take the hot sample in a metal “cooling” bucket and then transfer it to the sample container.

 

Image of Cooling Apparatus, Copper Coils in a Jar

Improvised Fluid Sampling Cooler

 


See Paratherm’s one-minute video on fluid sampling and testing here —
Heat Transfer Fluid Sampling

Sampling Part 1: Why

Why Sample?

Thermal fluids usually don’t telegraph that they are about to fail. Generally the only hint of impending doom is some fall off in temperature control in the heat user which requires an increase in the heater temperature to compensate.  Once the power is shut off and the fluid cools however, it’s a very different story.  If the fluid turns to molasses when it cools, it makes startup very difficult. Not to mention that pulling apart piping is a very time consuming way to replace the fluid.
If you operate a thermal fluid system, it’s easy to understand why thermal fluids fail. Unlike other central energy sources (like steam boilers) thermal fluid heaters don’t require (key word REQUIRE) any routine maintenance – no chemicals to add, no blowdown tanks, no condensate traps to mess with. Once you get beyond the initial startup the heater just runs.

 

This absence of required maintenance activities frees up operators for the 10,000 other items that do require attention. Which is why periodic sampling of the fluid should become a required maintenance activity.  Even if the sample isn’t sent out for testing, simply examining the cooled fluid will give you a hint about the condition –  i.e. if it doesn’t pour out of the sample container when you tip it over, you’re in trouble. (Here’s another hint: If this happens, don’t shut off the system. Give us a call.)

 

Cooled Sample, No Longer Liquid

“If it doesn’t pour out of the sample container when you tip it over…”

The next tip will review why where and how you sample is important.

 


See Paratherm’s one-minute video on fluid sampling and testing here —
Heat Transfer Fluid Sampling

Air and Heat Transfer Fluids, Part III

How well (or how poorly) does lab testing reflect real-world manufacturing conditions?

 

In the real world, oxidation of heat transfer fluids occurs in a vented reservoir or expansion tank that for whatever reason is hot (>70°C).

The acids formed in the expansion tank subsequently circulate through the system, decomposing in the heater and producing carbon sludge.

To determine which of several tests is more representative of the real world, several brands of fluid that contain additive packages were tested with the following methods:

  1.  A modified D-2440 test running at 200°C with 15 liters/hour oxygen for 24 hours – essentially an IP-48 (Institute of Petroleum Standards) test.
  2. The standard ASTM D-2440 test running at 100°C with 1 liter/hour oxygen for 164 hours.

Fluid Sample Prepared for Oxidation Testing

The IP-48 test trashed all of the fluids.  Acid Numbers ranged from 1.9 to 3.9 mg KOH/g sample (normal upper limit is 0.4).  Sludge ranged from 14 to 18 weight % (any sludge is a problem).

Glass Tube with Oil Sample and Oxygen Supply Inserted Into Heating Apparatus for IP-48 or D-2440 Tests

Prepared Sample In Heating/Oxygen Apparatus

The results of the D2440 test were more representative of what is expected from additized heat transfer fluids.  Acid Numbers were 0.01 to 0.03 mgKOH/g sample and Sludge was less than 0.1 weight %. We also tested fluids that contained no additive packages using the D-2440.  Acid Numbers were at least 30 mg KOH/g sample and Sludge was at least 1.5 weight %.