ParrNotes Newsletter Vol.1 No.2


A Quarterly Newsletter of Parr Instrument Company  |  June Edition 2014  |  Vol. 1 No. 2

Welcome to the second issue of ParrNotes

We are well into the second quarter of 2014 and business has been strong. Certainly I owe you, our dealers, a lot of gratitude for the efforts on our behalf in your respective markets. I’m always interested in hearing your ideas for improvement, or simply your comments about what’s going on in your part of the world. Please reach out to me anytime. For those of you in our Northern Hemisphere we are entering our much anticipated summer months. I wish you and your families good health, prosperity, and continued success.

Jim Nelson
President & Chief Operating Officer


Features and Benefits
Service Tips
Controller Section
Application Awareness
Parr Team Member Focus
How are we doing?
Upcoming Events

Features and Benefits

Custom 4670 High Pressure Vessel
Figure 1
Custom 4670 High Pressure Vessel

Higher Pressure 4580 Reactors and 4670 Non-Stirred Pressure Vessels

For customers looking to operate at high pressure and high temperature and requiring large working volumes, we have offered our 4580 Stirred Reactors and 4670 Non-Stirred Pressure Vessels with a standard rating of 3000 psi @ 500 °C. In response to several customer requests, and as a result of manufacturing multiple vessels with similar specifications, we are pleased to formally introduce modified versions of these vessels with a 4400 psi @ 500 °C rating.

To increase the rating of these vessels without altering the external cylinder dimensions so that standard heaters and stands may still be used, the following modifications are required:

  • Reduce cylinder ID from 5.5″ to 5.0″ with the corresponding volume reductions
    • Standard 1 gal (3.75L) → Modified ∼3.2L
    • Standard 1.5gal (5.8L) → Modified ∼4.8L
  • Widen flat gasket seal
  • Increase thickness of split ring
  • Increase size of bolts
  • Provide custom rupture discs (one installed with two spares, minimum)
Custom 4580 Non-Stirred Pressure Vessel
Figure 2
Custom 4580 High Pressure
Stirred Reactor

The following recent custom orders that had vessels with this rating are:

  • 914099, Stirred 4584 Reactor with ∼4.8 L volume, T316SS
  • 914951, Non Stirred 4672 system with ∼3.2 L volume, Alloy C-276

These modifications require a modest customization charge which varies based on applicable regulatory requirements and the material of construction (MOC) of the vessel. Note that this rating is available for vessels constructed of either T316SS or Alloy C-276, but please inquire about similar ratings for vessels with other MOC’s.

We continuously adapt our product line to customer specifications. If your customers are interested in the 4580/4670 series of vessels (or any other series!) with pressure and/or temperature ratings outside our standard offerings, please contact us with their requirements, and we will be happy to evaluate your request.

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Service Tips

Heater Loop Break and Unstable Jacket Temperatures with the 6200 and 6400 Isoperibol Calorimeters

A number of our calorimeter customers begin their day by starting their calorimeter and then will turn on the heater and pump. The pump will circulate the water jacket and the heater will run to raise the jacket temperature to 30 °C. The jacket is stable when the jacket water maintains 30 °C ± 0.5 °C. Once this stability happens the calorimeter will be ready for a pretest or operation. There are times where the user will receive a heater loop break error or the jacket temperature may not stabilize. We intend to help you and your customers understand these issues.

Heater Loop Break

Sometimes when the user starts the calorimeter they receive a Heater Loop Break error approximately 10 minutes after starting. This error happens when the heater runs at 100% for 10 minutes. The calorimeter does this to provide a warning that something might be wrong as it should not be heating at 100% for such a long time. In most cases the user can clear the error and restart the heater and pump. A second Heater Loop Break error would be a cause for concern. We typically see this error when the jacket temperature is less than 20 °C when the heater is first turned on. This happens most often when the seasons are changing or in the winter when laboratories are colder and the heater needs extra time to bring the water from room temperature to 30 °C.

Unstable Jacket Temperatures

Once the heater and pump are turned on some users have had issues with the jacket temperature rising to near 30 °C but bouncing high and low, never stabilizing. There are a couple of areas to look at to try to resolve this.

First check the water supply. There is a white elbow with a red cap on the lower back left side of the calorimeter. This elbow is where you can fill the internal water reservoir for the calorimeter. The user should always be able to see water in this elbow. Typically the user should add a little water every two to three weeks.


A1448DD Temperature Control Assembly
Figure 3
Thermistor in Temperature Control Assembly

Another area to check is the placement of the jacket temperature thermistor. The jacket thermistor is located in the top of the temperature control assembly, connected by a male connector. Sometimes (especially after shipping or a move of a calorimeter) this thermistor can slide down and sit on the bottom of the manifold. This will cause the thermistor to give unstable readings. To place this thermistor properly make sure the thermistor is to the bottom of the temperature control assembly then pull the thermistor up by approximately ¼ to ½ of an inch or 6.3 mm to 12.7 mm, then tighten the nut down so it is snug to hold the thermistor in place.

Other ideas that may cause unstable jacket temperatures are:

  • inconsistent water flow
  • bad thermistor
  • leaking or malfunctioning solenoids

If you have any questions about calorimeter jacket temperatures please contact us.

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Controller Section

RS-485 Daisy Chain – Controlling Multiple Controllers

The 4848 Controller is often used in conjunction with SpecView Software (Parr part number A3504HC). This powerful object oriented software package provides superior data logging capabilities. It is the same software that we use on our 4871 Process Controller, and it is commonly utilized on industrial PLC’s.

As part of a licensing agreement with SpecView, this A3504HC software has the ability to handle up to eight Delta meters. This is sufficient to run two fully loaded 4848 Controllers, or more as long as there are eight or less total meters represented.

Expanded configurations are available with the purchase of a “full” SpecView license, with the capability to handle up to 32 Delta meters. These must be done on a custom basis; please contact Parr about systems with more than eight Delta meters.

Connecting multiple controllers to a single PC requires some care, however. The standard A1925E4 Communication Cable is only suitable in cases where a single 4848 is attached to a PC. When multiple 4848 Controllers are attached, there is a greater concern that the ground potential on one of them will get too far away from the others. If this happens, a current will pass through the cable, knocking out communication at best, and destroying the converter at worst.

4848 Controller with A1925E4 Cable

The A1925E6 cable has resistance to this effect. It has an isolated converter, so the 4848’s and PC are not electrically connected, even though they maintain communication.

In cases where a single 4848 is attached to a PC the A1925E4 cable should be used, otherwise the A1925E6 should be used to connect one 4848 to the PC, and then each additional 4848 should be connected to the previous 4848 with an A2208E 10 foot RS-485 Daisy Chain Harness.

Please contact us if you are interested in learning more about connecting multiple controllers.

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Application Awareness

This recurring section in our newsletter will be dedicated to offering information about applications and/or industries where Parr equipment is being used or considered. We have heard from many of you that this type of information is valuable as you engage in your sales planning process and decide where to spend your effort, both in deciding on whom to call personally as well as how best to allocate your marketing funds. As a part of this section, we will also be asking for your input. For example, about what applications are you hearing that may be a fit for Parr equipment? Have you found an application or industry niche Parr might be better able to support with specialized accessories and/or options? This issue will attempt to offer useful information and ask for your feedback about a hot topic: BIOMASS. The usefulness and applicability of future columns depends on your feedback. Please send comments and questions for additional information to our Marketing Manager, Lisa Randolph, at Thank you!

Stirred Vessels for Biomass Applications

In the last several months, we have been receiving more and more inquiries for stirred reactors designed to work with biomass. We certainly welcome the interest, but we have noticed customer requirements vary widely. Though users of our traditional vertically oriented stirred reactors also have varied requirements, as we support uses from extractive metallurgy to polymer synthesis, many of these fields are more well defined than the relatively newer biomass applications. In the biomass world, process inputs are very diverse and range from sticks and intact sugarcane stalks to ground wood pulp fibers to viscous suspensions of algae. Each of these applications may require unique chemistry, as well as different approaches to effectively agitate the starting material.

We have had several recent requests for reactors that are to be used in processing cellulosic material to synthesize biofuel. This process often employs a dilute sulfuric acid solution added to ground or crushed wood or stalk material and heated to temperatures of 100 °C – 200 °C. We are told a critical requirement is the complete wetting of the sample to eliminate dry spots in the biomass. One way to approach this application is through the use of a reactor that can be loaded vertically, but operated in the horizontal position so that the solid material can be “tumbled” rather than stirred in a traditional fashion. Figure 4 shows two views of a one liter reactor on a cart that could be used in this manner.

Horizontal/Vertical Reactor
Figure 4
Custom Horizontal/Vertical Reactor with Spiral Stirrer

Vessel Loading

Loading variations may include initial loading of the sulfuric acid in the vertical position, closing of the vessel, and addition of ground biomass to the  cylinder once the vessel has been horizontally oriented through a solids charging port (Figure 5). Or both solid and liquid might be loaded prior to closure of the vessel.

Solids Charging Port
Figure 5
Solids Charging Port


Tilt Reactor Internals
Figure 6
Anchor Stirrer Modified for Horizontal use

Mixing configurations also vary. Some investigators have selected modified anchor stirrers similar to the one shown in Figure 6. You can imagine how this agitator might effectively tumble some high solids biomass mixtures to promote effective sample wetting. However, it may be ineffective for other applications with a different starting material.

One alternative is shown in the reactor from Figure 4 – a spiral stirrer. This stirrer is most typically used above in the vertical orientation. We also are happy to entertain the construction of custom stirrers to your customers’ specifications.

Operating Details

We ask for your help to work with customers to gather information about what their starting materials look like and what their planned process entails. We recognize some researchers may be reluctant to share process details, but any information you can obtain would be most useful. Information we look for to help determine the customers’ needs are:

  • working pressure
  • working temperature
  • liquid additives (for example, concentration and type of acid, etc.)
  • nature of the solid starting material (size, shape, etc.)
  • percentage of solids in their reaction mixture
  • whether they need to add liquid or solids while the reactor is at temperature and/or pressure

We believe that by collecting this information from a reasonable number of customers, we will be able to develop and offer better products that delight your (and our!) customers.

Thank you in advance for your partnership with us to better understand our customers’ needs. Though we will not share the specifics of your answers in order to protect the privacy of your customers, we look forward to compiling your responses and sharing general information as we get a better picture of how Parr Reactors are being used in biomass research.

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Parr Team Member Focus

Sailesh Pradhan, P.E., Senior Engineer

Sailesh Pradhan, P.E.,
Senior Engineer

Sailesh originates from the Foothills of the Nepalese Himalayas but says he does not even come close to being a Sherpa as the max height he has trekked is only about 4000 meters.

The great heights Sailesh has reached come in the engineering field by receiving his Bachelor of Engineering degree from the Birla Institute of Technology India and his M.S. in Mechanical Engineering from Southern Illinois University in Carbondale, Illinois, USA. Sailesh also holds the distinguished honor of being a licensed Professional Engineer.

Sailesh has been a member of Parr’s Engineering Department for almost eight years. He helps provide engineering related support in the design of our pressure vessel products as well as in regulatory aspects involving code calculations, material and weld certifications, etc. to both internal and external customers.

When asked what he likes most about his job at Parr Sailesh listed:

  • The Parr Team (friendly people who have made me feel at home from day one and are easy to work with)
  • The Parr Way (of always making things work right regardless of roadblocks or hurdles)
  • The Parr random-play button (the seemingly endless variety of tasks and challenges that come your way everyday)

Sailesh’s dedication to providing well-designed Parr products, his strong work ethic, and his affable personality make him a strong asset to our Parr team.

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How are we doing?

We want to hear from you! As mentioned earlier in the newsletter, we listen to our dealers and customers feedback and are always looking for ways to improve our products and service. Please take a few minutes to take our Parr Distributor Surveyto let us know how we are doing.

Our mutual customers may share their opinions on our Customer Satisfaction Survey.

Thank you for your continuous support in making Parr Instrument Company a company we can all take pride in!

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Upcoming Events

19th International Symposium on Homogeneous Catalysis
July 6-11, 2014
Ottawa, Canada

248th ACS National Meeting & Exposition
August 10-14, 2014
San Francisco, California

8th International Conference on Environmental Catalysis
August 24-27, 2014
Asheville, North Carolina

2014 International Organically Bound Tritium (OBT) Workshop
September 15-18, 2014
Ottawa, Canada

6th Symposium on Continuous Flow Reactor Technology for Industrial Applications Workshop
September 23-26, 2014
Budapest, Hungary

View our complete trade show schedule.

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