Application Spotlight: Lab Spectro­scopy

At PolyScience, we love sharing the unique and interesting applications we help customers find products for. Here, our Customer Support Representative, Andrew, explains how our equipment is used in analyzing stars.

My customer at New College of Florida has successfully used our 15L Refrigerated Circulating Bath with Advanced Digital Controller (AD15R-40-A11B) and polycool HC -50 fluid (part number 060330) in his current application.

The indirect detection of elements and molecules through spectral signatures in space would be something you would think would need to be studied in space. Not any more! Lab spectro­scopy is becoming a very effective way to study the elements of stars in the lab here on planet Earth.

My customer is a high-resolution spectroscopist that collects the rotational spectra of molecules in the gas phase to help radio astronomers find new molecules in interstellar space.

One of the things that is required is to cool down the sample cell. This helps make the spectra that is produced less complicated and more intense than they would be at room temperature. The sample cell itself is a coiled piece of waveguide (think of it like fiber optic for microwaves) that is filled with the molecules that he is interested in.

This is where our AD15R-40-A11B comes into play. He is pumping polycool HC -50 externally through 60 ft of tubing formed as a coil around his sample cell. He is successfully maintaining very low temperatures, and desired stability with this set up.

• Temperature range: -40° to +200°C
• Temperature stability: ±0.01°C
• Maximum pressure flow rate: 20.1 l/min (120V); 16.7 l/min (240V)
• Maximum suction flow rate: 14.7 l/min (120V); 12.2 l/min (240V)

Application Spotlight: Asphalt Sample Tempering

Application
Here in Chicago the home of PolyScience, people joke that “There are two seasons in Chicago—winter and construction”. Now that it seems that the winter season has finally come to an end; we are starting to see our second season, road construction, begin.

In Chicago and the rest of the U.S., many of the roads are constructed using asphalt. Asphalt, which is also known as bitumen, is a form of black petroleum with viscosity levels spanning from highly viscous to semi-solid. Asphalt can be found in natural deposits or may be a refined product. When the asphalt is combined with stone, sand or gravel, asphalt pavement is created. In the process of creating road paving materials, asphalt is used as the “glue” or “binder” and accounts for only a small percent of the total material used.

In addition to its binding properties, asphalt is known for having excellent water proofing capabilities and due to its smooth surface, cars that run on asphalt experience better fuel economy along with reduced wear and tear on tires and shocks.

Temperature change causes asphalt to expand and contract, and as a result, is subjected to many types of testing in order to make sure that the road material is flexible enough to withstand not only extreme climate conditions, but also continuous traffic stress. Asphalt sample tempering is just one of the many tests performed.

Asphalt sample tempering tests the asphalt’s degree of ductility. Ductility is the amount of maximum stress that the bituminous material can withstand while being stretched or pulled before cracking. A ductility test machine is used for this process. It measures the distance a standard asphalt sample will stretch without breaking when pulled at a constant rate under standard temperature testing conditions (5 cm/min at 25°C).

Asphalt sample tempering helps to ensure proper characteristics are maintained within the asphalt mixture to prevent cracks from developing.

What PolyScience product is used when performing asphalt sample tempering tests?

Solution
A PolyScience Refrigerated Circulator provides the precise, controlled temperature needed to monitor the ductility of the asphalt mixture used for road construction.

Features
•Working temperatures from -40° to +200°
•Temperature stabilities to ±0.005°C
•Capacities from 7 to 75 liters
•Six controller types with large, intuitive displays and multiple communication options
•Large bath openings and easy to clean surfaces
•Swivel 180™ Rotating Controllers
•LidDock™ Lid Stowing System
•DuraTop™ Chemical Resistant Deck
•WhisperCool™ Environmental Control System
•Cool Command™ Technology

Application Spotlight: Fermentation in Winemaking

The Application:
The history of wine spans thousands of years and predates written records leaving archeologists unable to definitely determine, the location or time period that the first wine was produced.

In simplest terms, wine is an alcoholic beverage derived from fermented grapes. Fermentation takes place when yeast consumes the natural sugar present in grape juice and converts it into alcohol and carbon dioxide. In winemaking there are two stages of fermentation: primary (aerobatic), followed by secondary (anaerobic) fermentation.

During fermentation, it is vitally important to maintain the right temperate to cool the juice of the crushed grapes. If the temperature is too cool the yeast will not ferment. Temperatures that are too warm will result in wine that has fermented yeast but the can cause microorganisms to form which will distort the taste of the wine and can cause spoilage. The optimum temperature for wine fermentation is thought to be 72°F/22.2°C but can range from 65°F/18°C to 77°F/25°C depending on the type of wine.

Cooling is also important in the last stage of winemaking before bottling to remove potassium bitartrate, or tartrate, a harmless but unsightly sediment. This removal process known as cold stabilization calls for the wine to be chilled to a temperature of about 27°F/-2.7°C for up to 24 hours which causes the tartrate to predicate out of the wine and then filtered out.

What PolyScience product is needed to remove heat from the juice in order to keep the fermentation process stable and to precipitate the tartrate?

Solution:
PolyScience’s 6000 Series Chiller with a ¾ HP motor has the power you need to remove heat during both fermentation and cold stabilization. The 6000 Series can be with connected to cold plates in order to chill large quantities of wine all at once.

Features:
• Large, dual displays present temperature and pressure or flow rate simultaneously
• Compact, portable design takes up less floor space
• Cooling at ambient temperatures as high as 35°C
• Choice of pumps and compressor sizes
• User-adjustable temperature, pressure, and flow rate alarms
• Heater option extends cooling temperature to +50°C, provides the ability to apply heat up to 70°C; ideal for applications, such as lasers, that must be brought to a temperature above ambient before operation can begin
• External temperature tracking and communications capability (optional)
• Cool Command™, WhisperCool™ (3/4 and 1 HP models)

To learn more about the many options available in the 6000 Series Portable Chillers click here

Temperature Terminology: Accuracy and Stability part 2

Have you read our blog here but are still looking for more information about the differences between accuracy and stability? It’s a common question so here is some more information that should answer any remaining questions.

Stability is the generally accepted term when discussing the “reliability of the temperature measurement.” It refers to how precisely the temperature is maintained over time. For example, the stability of our Advanced Digital Controllers is ±0.01°C throughout its entire temperature range. This means the variance throughout the temperature range is ±0.01°C, regardless of whether the temperature is set to -20°C, 20°C or even 200°C.

Accuracy is less frequently used and is often confused with stability. Accuracy actually refers to the potential difference between the physical fluid temperature and the digital readout when compared to a known standard; usually a calibrated thermometer or other extremely reliable piece of instrumentation. We use the “Gold Standard” in our industry to measure our accuracy: the Hart instrument, which is completely linear throughout its temperature range. The readout used in this unit covers the entire range (-20° to 200°C), but may not be linear at the high ends of this range. The potential differential could be 0.25°C. Given this information, if Customer X is, for example, operating at 100°C and finds there is an accuracy difference of 0.25°C (compared to a reliable instrument), he can program in an offset differential to make the readout agree with the external measuring instrument. For this instrument, accuracy rating is generally accepted at ±0.15°C @ 0°C. This variance can increase as the temperature goes up or down (as a reference point, at 100°C, this variance can be 0.35°C). Upon customer request, PolyScience can also provide single-point calibration services.

Application Spotlight: Wort Cooling

The Application:

Beer, the world’s most consumed alcoholic drink, is also considered to be one of the oldest fermented beverages. Beer brewing is a multi-step process that greatly depends on both precise heating and cooling during certain points in its production to create a successful brew. There are seven main steps to brewing beer before the final step of packaging: malting, milling, mashing, brewing, cooling and fermentation, maturation and filtering.

To make beer, brewers use water and barley to create a sweetened liquid called wort, which they flavor with hops, then ferment with yeast. Midway through the process, during the brewing step, it is necessary to boil the wort for one to two hours depending on the beer’s final preferred flavor, color and aroma.

Immediately following brewing, the next step is cooling. When cooling it is vitally important to quickly cool down the wort so that yeast can be added to begin the fermentation process. If you wait too long, microbes can enter into the wort and cause the beer to be ruined.

What PolyScience product can quickly cool down the wort in order to add yeast for fermentation?

The Solution:
A PolyScience Benchtop Chiller coupled with an external cooling coil can quickly cool the wort to the optimum temperature needed. When used in small volume applications, this cooling combination can safely cool the wort in a fraction of the time as compared to other traditional brewing methods.

Features
• Large, easy to read LED display
• Space-saving design
• Cooling at ambient temperatures as high as 35°C
• Low flow shutoff and alarm, high and low temperature alarms
• Front mounted fluid level gauge
• Simple setup, operation, and maintenance
• Choice of pumps

For additional information on PolyScience’s line of Benchtop Chillers, click here

Application Spotlight: Injection Molding

 

The Application:
Injection molding is a process where different types of materials including metal, glass, plastics or polymers are melted down and pressure injected into a mold to form parts. While the first injection molding machine was patented in 1872, the most commonly used model today is the Screw Injection Machine developed in 1946. It operates when the melted material of choice is fed through a heated barrel in the screw injection machine and forced into a mold where the impression cools and takes shape.  Today, injection molding is the most common process of plastic manufacturing because of its ability to consistently produce a high volume of parts while at the same time reducing waste as a result of melting down and reusing scrap that is produced.

Plastics that are used in plastic injection molding fall into two categories-thermosetting or thermoplastic. Thermosetting plastics are set by application of heat or through catalytic reaction and once they are curing they cannot be re-melted or reused. Thermosetting plastics include epoxy, polyester and phenolic resins.

Conversely, thermoplastic plastics can be heated, melted and reused if needed. Some examples of thermoplastics include nylon and polyethylene.

As part of the injection molding process, the plastic needs to cool down in the mold where it can be later removed. In order to do this the mold needs to be cooled quickly so that the plastic can harden to its final shape and be released from the mold. What can you use to quickly cool the molds down?

The Solution:
DuraChill 2 to 3 HP Portable Chiller

Our line of DuraChill portable chillers in 2-3 HP range has the high capacity cooling needed for injection molding applications with features that include:

• Displaying temperature and pressure or flow rate simultaneously
• User-adjustable temperature, pressure and flow rate alarms
• Simple operation and maintenance
• Air- or water-cooled (3 HP models)
• Wide variety of pump options available 

Key Specifications:
Working Temperature: +5° to +35°C
Temperature Stability: ±0.5°C
Cooling Capacity: Up to 10,936 watts @ 20°C

 Additional chiller sizes are available. Click here for more information.

How do Chillers Differ from Circulating Baths?

A Circulating Bath describes a broad category that includes immersion circulators and heat-only and refrigerated/heated baths (PolyScience provides over ninety models). Options include six types of controller heads, multiple sizes of reservoirs and a choice of stainless steel, insulated stainless steel or polycarbonate tank.

A Chiller removes heat from process fluid in two different ways. Liquid-to-air is where the chiller blows out the heat from the process fluid into the air surrounding the unit while liquid-to-liquid is where the chiller transfers the heat absorbed from the process fluid to another fluid to cool.

Key Differences
Size: A circulator is generally smaller, more versatile and is geared more for laboratory use while a chiller tends to be larger and used for both laboratory and industrial applications. Also, you can place items such as beakers and test tubes directly inside of a circulator reservoir. This is not possible with a chiller. With a chiller, you are circulating the cooling fluid from the chiller out to the piece of equipment or application that needs to be cooled.

Cooling Capacity: Due to its larger size, chillers having more cooling capacity, higher pumping volume and pressure than a circulator and provide more heat removal.

Temperature Control and Accuracy: A circulator has a higher range of temperature control from temperatures ranging from -40° to 200°C and temperature stability as precise as ±0.005°C, as compared to chillers with a temperature range of -20° to +40°C and temperature stability of ±0.1°C.

Heat Removal: Chillers have stronger heat removal than circulators.

Pumping Volume: A chiller has a larger pumping volume and more pressure capacity than a circulator.

Pump System: A circulator has either a closed-loop or open-loop pump system and a chiller is used almost always in a closed loop. Also, 6000 Series Chillers have three different pump options: turbine (high flow at high pressure – more forgiving to impurities in the fluid system), positive displacement (moderate flow at high pressure) or centrifugal (high flow at low pressure).

Customization: Circulators offer more standard variations designed to fit a wide range of applications; while chillers, specifically DuraChill, offer more customization and factory installed options to give each unit a unique fit.

Product Selection Tips- Temperature Range and Heat Removal

The temperature range and required heat removal go hand in hand, and while knowing about one of these is great, knowing the desired temperature range and the required heat removal is even better.

PolyScience Chiller

Meeting the temperature range requirements is easy, but even meeting this specification can become difficult if cooling capacity requirements aren’t met. This is because the unit will struggle to maintain temperature and even look like it isn’t functioning, even though it is.

PolyScience Refrigerated Circulating Bath

While both Chillers and Circulating Baths have the capability of maintaining temperature, Chillers are capable of removing more heat – a lot more. Chillers remove at least 800 watts @ 20°C, but do have a more limited temperature range. Circulating Baths, while more precise and stable, and often equipped with additional features – including enhanced communications options – offer a broader temperature range (up to -40° to 200°C; controller dependent), but will not remove as much heat.

Overall, there are times and places for both Chillers and Circulating Baths. While Circulating Baths can be used to achieve higher temperatures, Chillers are the product when looking to remove heat from a piece of process equipment, like a machine press (in which heat load can be as much as 2900 watts at 20°C).

As always, PolyScience has a staff of dedicated Sales and Customer Service Representatives available to answer any questions and help you pick the perfect product for any application. Click here to contact us.

Application Spotlight – Membrane Filtration Testing

The Application:
Many industries, including food & beverage, pharma, and biotech, utilize a membrane. A thin, film like item, a membrane provides a selective barrier and allows only certain particles/chemicals to pass. Different membranes are used for different things, but some applications include:

• Removing toxic substances
• Filtration (particularly in the food industry)
• Recovery of organic vapors

Membranes, like many other items, undergo testing to ensure they exhibit the required properties. Testing includes:

• Permeation testing
• Pressure decay tests
• Bubble point tests
• Fouling experiments

One of the machines used in membrane testing is the Convergence Inspector UFR. Convergence, located in the Netherlands, makes R&D test systems, quality control systems, and other solutions for fluids and gases. The Convergence Inspector UFR is a customizable system that can be used with fiber bundles for dialysis membranes. The Convergence Inspector UFR flushes, cleans and does the permeation tests at 37°C.

The Solution:
PolyScience Circulating Baths provide the temperature control required by the Convergence systems. Easily integrated into the automated systems with the use of Modbus (other baths on the market offer limited connectivity options – sometimes only RS-232 and/or RS-485), Circulating Baths provide the needed temperature control.

Refrigerated/Heated and Heat-Only Circulating Baths are available in a range of sizes, offer different levels of stability, and include different temperature ranges, providing the temperature control requirements specific to customers’ needs.

For more on PolyScience Circulating Baths, click here.

Product Selection Tips- Knowing the Application

Having some sort of knowledge of the application can be very helpful and may even help you narrow down the product list to a specific series or model. And if you’re using the product, you’ll know the application very well. However, if you’re a distributor or buyer, here are some examples of how knowing the application can help with product selection.

Example 1: If the end-user/customer works in a blood bank, PolyScience has an easy solution that fits the bill the vast majority of the time: The Cryoprecipitate Bath (pictured). Designed to run at a fixed 4°C, the Cryoprecipitate Bath is ideal for thawing Fresh Frozen Plasma (FFP) or Whole Blood (WB) and can even thaw up to 24 units simultaneously.

Example 2: Knowing the heat transfer fluid that will be circulated also helps. For example, if the operator is using silicon oil, which is used for higher temperature ranges, we know that the operating temperature is probably above 100°C.

Example 3: When working with rotary evaporators, which utilize delicate glassware, it is known that units with high pressures should be avoided. (Generally, we recommend our Benchtop Chiller models.)

While there are many examples of how the application helps determine which products should be selected, those were just a few to demonstrate the idea. As always, PolyScience has a staff of dedicated Sales and Customer Service Representatives available to answer any questions and help you pick the perfect product for any application. Click here to contact us.