A Quarterly Newsletter of Parr Instrument Company | December Edition 2014 | Vol. 1 No. 4
Welcome to ParrNotes
Welcome to the last issue of ParrNotes for 2014. What a year it has been. I want to thank all of you, our dealers, customers, and most importantly, our outstanding employees for making 2014 a very successful year. We will by all accounts set records for our business in 2014. While our standard product continues to be very successful, the market has gravitated towards more complicated custom engineered systems with sophisticated controls. These types of projects require more engineering and sales support, but our team has responded well and we are finding success in this marketplace leading to our largest single order in Parr history in 2014.
Despite a great year, there is no time to rest on our success. I am looking forward to 2015 as we continue to build and strengthen our team here in Moline. In the last half of this year we have added three more sales people; Kevin Lucas, Sarah Varan, and Ashlee Lopez. Later in December we are bringing aboard Dr. Andrei Yermalayeu to add some depth to our product development efforts. We are busy planning our sales and marketing efforts and show schedules for 2015. I will see many of you at ACHEMA in Frankfurt next June.
The extended Parr family around the world is represented by many religions, customs, holidays, and even New Years. My common wish is for all of us to enjoy time with family and be blessed with peace, good health, and prosperity in the coming year.
With kind regards,
President & Chief Operating Officer
Honoring 40 Years of Service
Linda Paradiso Set to Retire
After dedicating 40 years of service, Parr Instrument Company’s National Sales Manager, Linda Paradiso is ready to tee off on a new course.
After graduating from Dubuque University with a Spanish degree, Linda joined Parr in 1974 as the company’s receptionist. Her pleasant personality was very welcomed.
Before long, Linda was helping with purchasing activities and taking orders that were phoned in. Eventually Linda was moved into the sales department where she continually found new ways to sell our products, challenging our engineering department to customize or modify existing designs.
Linda is an expert on our products and has been a well used resource due to her amazing ability to recall pertinent product details by memory. There is often a line of colleagues outside of her office waiting to get her expertise, opinion, or approval on all aspects of the company.
After she retires on December 19th, Linda will be escaping to the warmer climate of Arizona with her husband Tom and her mother. While there, Linda will be found mostly on the golf course.
Linda has been an innovator, a strong leader, and a cornerstone of our company. We will all miss her greatly and wish her a very long and happy retirement.
Share your favorite stories, memories, and well wishes for Linda here!
Features and Benefits
Custom External Catalyst Addition Devices
An external catalyst addition device in the head of a reactor can serve as a convenient solids charging port at atmospheric pressures. The body of this device is machined with an internal taper to aide in the delivery of the solids into the vessel. It has a convenient screw cap closure. These devices are offered in a variety of sizes to compliment our reactor volumes.
Recently, we have offered custom external catalyst addition devices (XCAD) for some of our systems to compliment our standard atmospheric XCADs. These custom XCADs have incorporated a cooling sleeve, ball valve, and sealed screw cap vessel that would allow a customer to add the catalyst while the system was under pressure and heated to a set temperature. Previously, this could only be accomplished with an internal catalyst addition device (CAD). The Internal CAD was restricted to solids only and limited volumes.
This XCAD can be used in place of our solids charging port (SCP) for some systems. Even though the ball valves are not rated to the same temperature as the system, if the cooling sleeve is used to keep the ball valve below 100 °C, then this arrangement could be used on systems at a higher temperature. The customers should be aware that the rating on the ball valve is restricted and use of this device is dependent on the cooling feature provided.
Since the vessel used for this XCAD is based on our 4790 Series Non-Stirred Pressure Vessel, the volumes have been between 50 mL and 125 mL for the custom systems. A ball valve is needed along with a tapered bottom on the cylinder to facilitate the addition of both slurries and solids with this device. It could also be used for liquids.
This feature can be used for some high pressure systems, rated up to 5000 psi, if an appropriate ball valve with a 5000 psi rating @ 100 °C is used. We have provided some of these XCADs without a cooling sleeve option which would be suited for lower temperature conditions due to the ball valve rating.
If one of your customers is interested in adding this accessory to one of their new reactor systems please do not hesitate to contact us for additional information and pricing.
Parr Calorimeters – Using Your Ears
In addition to error messages and other indications from the calorimeter it is also important to use your eyes and ears when troubleshooting. This article will talk about using your ears.
When troubleshooting a 6400 Automatic Isoperibol Calorimeter you want to listen to a number of things. Is the circulating pump gurgling? If so, air may be trapped inside the pump. This will cause a significant decrease in flow through the jacket. This in turn could cause the jacket temperature to be unstable. If there is enough water in the main reservoir then simply turning off the heater and pump, waiting 10 seconds, then turning it back on is usually enough to clear the air.
Listen to the whoosh of the exhaust after a test or a pretest. Does it sound weaker than normal? A weak exhaust could indicate an oxygen leak during the test or pretest.
With the head removed listen to the cylinder. If you hear a hissing or bubbling sound it could mean that oxygen is leaking past the O-rings on the piston under the bucket.
While these above tips are focused on the 6400 Calorimeter the pump and exhaust tips will also apply to the 6200 Isoperibol Calorimeter.
External Temperature Limit Module
The External Temperature Limit Module, or ETLM, is a feature that was introduced as a standard option with the 4848 Reactor Controller. With this option the heater is equipped with a side mounted thermocouple which sets against the outside wall of the vessel. The secondary temperature module then acts as an on-off temperature controller, allowing power to the heater only if the external thermocouple is at a lower temperature than the desired external set point. The end effect of this setup is that the set point of the ETLM effectively limits the maximum temperature the heater can achieve.
The ETLM’s most common purpose is to protect a PTFE liner, but it is also used to limit wall temperatures for long thermal lag processes such as polymerizations or gas phase reactions, or simply to get a measurement of the wall temperature for data collection purposes. In general, if it takes a long time for heat to transfer from the vessel wall to the thermocouple, the ETLM should be considered for good temperature control.
Finding an Appropriate ETLM Set Point
Getting the right ETLM set point is important. If the ETLM keeps the heater temperature too low, the internal temperature will never reach set point. Set the ETLM too high, and it won’t do a good job of protecting the liner or preventing other side effects (i.e.- undesirable reaction, scorching, deactivation, etc.).
In cases where the ETLM is protecting a liner or other side effect, the maximum ETLM setting is straight forward; it must be set low enough to prevent the scenario you’re trying to avoid.
In cases where the ETLM is not needed to protect/prevent anything, the set point can be set to something significantly higher than the internal set point. To determine what setting will not interfere with the heat up rate, it is useful to do a run with the ETLM set point at 1200 °C, and then observe or log the ETLM temperature during the run to see how high it gets. Then change the set point accordingly on the next run.
Use as Temperature Control Device
The ETLM can be used as a quick-and-dirty means of minimizing temperature overshoot, but is generally not the best means to achieve good temperature control. If the ETLM is used to keep the wall temperature marginally above the intended operating temperature, it will effectively limit the overshoot, but it will take significantly longer to heat up too.
A more commonly recommended temperature control approach is to auto tune the Primary Temperature Module, a standard feature in the 4848 Controller. There are other approaches as well; contact Parr Technical Sales Team for an opinion on a suitable temperature control approach.
Inverted Temperature Issues
A handful of cases have been reported where the ETLM reads an external temperature that is below the internal temperature. This issue tends to surface on systems with very powerful heaters, small heating surface areas, and lots of heat loss through the head such as our 4575, 4576, and 4590HPHT systems.
The trouble is that the thermocouple is located in a cold spot on the heater. The average heater temperature is well above the ETLM reading, and the heat can permeate to the internal thermocouple faster than it permeates to the external thermocouple.
This discrepancy can be mitigated by relocating the external thermocouple to a different place. In some cases there is a second external thermowell location in a warmer spot on the heater.
For further information on temperature control, please contact the Technical Sales Team at Parr Instrument Company.
Supercritical carbon dioxide refers to carbon dioxide that is in a fluid state at or above its critical temperature and pressure. Fluids in this state are so energetic from the heat that all the pressure one might apply will never be enough to cause condensation back to a liquid. This leads to some very interesting properties.
Carbon dioxide usually behaves as a gas at ambient conditions. It can also exist as a solid, called dry ice, when frozen. If the temperature is increased from ambient conditions to be at or above the critical point for carbon dioxide, it can have the properties of both a gas and a liquid simultaneously. More specifically, it is said to behave as a supercritical fluid above its critical point. The critical temperature for CO2 is 31.1 °C, at which point its vapor pressure is 72.9 atm (1071 psi; 7.39 MPa).
Supercritical CO2 has become an important industrial solvent due to its low toxicity and environmental impact. It achieves the solvent power of a liquid while simultaneously achieving the penetrating power of a gas. The relatively low critical temperature and the stability of CO2 also allow many compounds to be extracted with little damage to their structure.
Areas of application for supercritical CO2 include decaffeination of coffee, cleaning of many industrial and home products, nano-particle formation, and polymer foaming to name just a few.
In an analogous manner, water can also become a supercritical fluid. In this case, the critical temperature is 374 °C at which point its pressure will be 218 atm (3185 psig, 22.1 MPa). This, now highly energetic fluid can be used to invoke considerable damage to compounds.
Supercritical water is especially aggressive, so much so that stainless steel will be corroded by its containment. Other alloys, such as C-276, may be more appropriate. Even the more mildly aggressive supercritical CO2 has some unique problems. Of primary concern is the use of elastomers. Because of their porosity, O-rings such as FKM are easily penetrated by supercritical CO2. Upon depressurization, the rapidly escaping gas will tear an O-ring apart in a process often called Explosive Decompression.
It is interesting to note that as the density of a gas increases with temperature and pressure, the density of a liquid is decreasing as the temperature increases. It turns out that the density of both phases becomes identical at the critical point.
It is also interesting to note that the viscosity of a liquid decreases with increased temperature and that the viscosity of a gas increases with higher temperatures. Want to venture a guess at where they have the same value? Yes, correct; they are the same at the critical point.
Parr Team Member Focus
Randy Steining, Chief Financial Officer
Randy has a degree in accounting from the University of Northern Iowa and a Master of Science in Taxation degree from DePaul University. He passed the CPA exam and practiced in public accounting for 10 years prior to joining Parr.
Randy has been with Parr for 3 ½ years and works in the finance, accounting and human resource functions of the business. He really enjoys working for the team at Parr and can’t say enough about the world-class folks involved in all aspects of the operation. Randy is honored with the opportunity to contribute to the strong tradition of Parr Instrument Company.
Randy is married and has three young children that he spends most of his time with outside of work.
249th ACS Spring National Meeting and Expo
March 22 – 26, 2015
Will you be representing Parr at any trade shows in 2015?
If so, please let us know at firstname.lastname@example.org and we will be glad to add them to our Trade Shows page. We also love seeing photos from the shows so please share those as well!