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Centrifugal Chillers

Brooke Loeffler · Jul 23, 2019 ·

What Goes Around Comes Around

Centrifugal chillers are one of the hardest working machines behind the comfort that we enjoy everyday. When we visit movie theaters, grocery stores, or office buildings and feel the cool relief of air conditioning as we enter, we have centrifugal chillers to thank.

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Centrifugal chillers are typically the most economical chiller to use for cooling sizable buildings. They can efficiently produce a high flow rate and are ideal for larger applications. Centrifugal chillers usually have fewer moving parts than other varieties, and with less mechanical friction are more cost effective to maintain. Some cooling applications require greater portability and lower cooling temperatures than centrifugal compressors are built to produce. Their range of usefulness is limited by their large footprint and emphasis on volume instead of cooling power.

Types of Compressors

Positive Displacement Compressors

There are 4 main types of compressors found in vapor compression chillers: scroll, screw, reciprocating, and centrifugal. Scroll, screw, and reciprocating compressors work through the process of positive displacement. Positive displacement compressors capture gases into a chamber, then reduce the volume of the chamber to cause compression.

Centrifugal (Kinetic) Compressors

These compressors use centrifugal force to turn kinetic energy into pressure. As gases enters the compressor, they are spun radially outward causing them to compress. Centrifugal force then throws the gases back out at a high velocity.

Centrifugal Force

Centrifugal force is an inertial force that acts on all objects rotating around an axis. It is the same compressing force you feel in many carnival rides or when you make a u-turn in your car, and is a very energy efficient method of compression.

A common centrifugal force experiment is to take a bucket of water and, with a straight arm, quickly rotate at the shoulder and swing the bucket upward and around a vertical loop. Centrifugal force compresses the water enough to counteract gravity so that even when the bucket it upside-down, the water stays in the bucket.

North Slope Chillers diagram explaining centrifugal force within a centrifugal compressor

Centrifugal compressors take this force one step further with expelling the gases out at a specific point in the radial spin. This is best explained by imagining a ball at the end of a rope. If you were to swing the rope vertically around an axis (your hand) at a high velocity, centrifugal force will be pulling the ball outward. When that rope is released at the correct angle, the ball will exit the loop at a high speed and be hurled upward.

Parts of a Centrifugal Compressor

Basic centrifugal compressors are made from 4 main components: an inlet, impeller, diffuser, and collector.

North Slope Chillers diagram on the components of a centrifugal compressor

Inlet

An inlet is a pipe in which the gases enter the compressor. Some inlets are open and simple, others contain valves or channels to direct flow in the direction needed inside the compressor.

Impeller

Impellers are the key component in generating centrifugal force. Rotors with carefully angled vanes or blades spin and raise the energy of the gases inside the compressor.

Diffuser

These high velocity fluids or gases are thrown outward and hit the diffuser which converts the kinetic energy into pressure by reducing the velocity. Diffusers accomplish this in a variety of ways, such as channels or wedged vanes for the high velocity substance to compress against.

Collector

The collector is an empty chamber which gathers the flow coming out of the diffuser. The shape of a collector varies greatly but typically resembles a nautilus shell so it can collect around the entire radius of the impeller and diffuser. Collectors can also sometimes contain valves or other components.

Chilling Solutions

Industrial chillers and their components should be carefully selected so they are ideally situated for the application at hand. Understanding the function and benefits for different compressors can help you find a tailor made chilling solution for your needs.

Chilling Solutions From North Slope Chillers

North Slope Chillers offers easy to install, portable chillers that won’t disrupt your current setup. Contact us to find the chilling solution for your needs:

(866) 826-2993 [email protected]

Biotech Cooling Chambers

Brooke Loeffler · Jul 20, 2019 ·

Where Test Tubes Chill Out

Biotech laboratories rely on precise temperature control to initiate, stabilize, suspend, and stop sensitive chemical reactions. Experiment integrity, equipment protection, and lab-worker safety can all be compromised if precise temperatures are not met at precise times. Let’s take a closer look at a common piece of temperature control equipment used in biomedical research and production: cooling chambers.

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What Are Cooling Chambers?

Cooling chambers are anodized aluminum storage racks that are specifically designed to store and transfer sensitive liquids. They have grids of wells that can safely house configurations of different sized test tubes and vials while they are being chilled. The anodized aluminum prevents corrosion and ensures cold temperatures are sustained in each lab sample.

What Are Cooling Chambers Used For?

Aluminum cooling chambers are used in many different laboratory applications as samples are put through a process called thermal cycling.

Thermal Cycling

Clinical laboratory research requires meeting exact temperatures for exact periods of time in order to produce accurate results. Thermal cycling exposes reactants to repeated cycles of heating and cooling to start, stop, suspend, or stabilize chemical reactions. One of the most common uses for thermal cycling cooling chambers is a method called PCR (Polymerase Chain Reaction).

PCR

PCR was developed in 1993 by Kary Mullis as a precise method for copying strands of DNA. DNA strands are suspended in tubes of liquid and housed in aluminum cooling chambers while they are thermally cycled. The DNA goes through anywhere from 20-40 different temperature stages causing it to melt, elongate, bind, and reform as needed. Thermal cycling for PCR has become critical to many different industries from medical research to forensic analysis.

How Are Cooling Chambers Thermally Cycled?

Cooling chambers can be housed in many different types of containers as they hit their required temperature targets. These containers range from large fridge-like chambers that are specially calibrated for thermal cycling to small foam ice-chest sized boxes with cooling blocks that can be stored on a counter top.

Total Temperature Control From North Slope Chillers

North Slope Chillers offers portable, easy to install chillers that won’t disrupt your current setup. For more about our temperature control products, contact us: (866) 826-2993 or [email protected].

Benchtop Chillers

Adam Jacobs · Jul 18, 2019 ·

When Smaller is Better

Industrial chillers come in a variety of sizes. How small can chillers get?

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All sizes of Cold

Chillers are an essential part of any workplace where temperature control is concerned. They come in all shapes and sizes, usually specific for the cooling task they were built for.

The Little Chiller that Could

While some chillers are built to handle literal tons of heat, some only have a small job to do. These are often referred to as benchtop chillers. These miniature cooling units are the George Foreman Grills of cold: small, portable and efficient.

Benchtop chillers can be used while sitting on top of a work desk. Their size makes them ideal for keeping small amounts of material cold while still providing an industrial-grade of chill.

Learn More

Want to learn more about chillers? You’re at the right place: North Slope Chillers is the world’s best expert in keeping things cold. Check out our chiller guide to determine what size of chiller will fit your needs, or call 866) 826-2993 to talk to one of our chilling experts.

Fermentation Cooling Jackets

Brooke Loeffler · Jul 16, 2019 ·

Wrap Up To Stay Cool

Whether you are wine making, distilling, or brewing, temperature control during the fermentation stage is crucial. Keeping fermentation chambers within specified temperature zones ensures ideal flavors, colors, aromas and alcohol levels in your drinks.

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Fermentation containers come in all shapes and sizes: from massive steel chambers, to medium conical fermenters, all the way down to small car-boy fermenters for small batches and home brewing.

The methods of cooling these chambers are as varied as the fermentation containers themselves. These chilling methods can be approached from two directions: inside or outside.

Cooling From The Inside

Some fermentation chillers involve inserting a cooling rod or coil down into your fermenting liquid. These devices then cool the liquid through direct contact. Cooling a fermentation container from the inside comes with added risks. Anytime a tool or device is inserted into your fermenting liquid, you risk exposure to unwanted microorganisms (such as wild yeasts) that can alter flavors, as well as bacteria, potentially tainting your drink. Opening a fermentation chamber to insert cooling devices also increases the change of oxidization spoilage.

Using this cooling method also greatly decreases the chilling efficiency. Fermentation liquid is exposed to a much smaller cooling surface area, leading it to not cool as effectively, especially for medium to large batches. This also increases the risk of hot and cool spots in the fermenting liquid, making it harder for the yeast to finish the fermentation process.

North Slope Chillers infographic showing the benefits of using a fermentation cooling jacket

Cooling From The Outside

Chilling fermentation chambers from the outside is the most effective method. No matter the diameter of your fermenting container, the outside surface area will always be greater than cooling from the inside. Putting the chilling source in direct contact with the fermentation container will produce the best results due to uniform thermal flow from the container to the chiller. As fermenters come in all shapes and sizes, cooling sources should be as flexible as possible to ensure complete contact with the container.

North Slope Chilling Solutions

Fermentation cooling jackets that completely wrap around your fermenter will give you the most direct cooling contact. Insulated Fluxwrap jackets from North Slope Chillers have multiple channels of cooling liquid evenly distributed around your fermentation chamber. Their adjustable temperature range will eliminate hot or cold spots and keep your yeast happy and fermenting. Fluxwrap is easy to install without opening your fermenting container and flexibly fits a wide variety of container shapes and sizes.

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Cooling in the Biotech Industry

Emma Pollock · Jul 8, 2019 ·

Process cooling can be used almost anywhere, even in the biotech industry! There are many pieces of biotech laboratory equipment that need stable temperatures in order to perform necessary experiments or processes. Additionally, specific materials and samples must be carefully kept at ideal temperatures. Fortunately, there are many options when it comes to process cooling equipment that perfectly meet the needs of biotech applications.

What is Process Cooling?

First, let’s take a look at the basic idea of process cooling. In most process cooling systems, a water chiller is used. In a water chiller, a pump circulates cold water from the chiller, to the process (process: machine/system being cooled). The cool water pumped through the system removes heat from the process. Warm fluid returns back to the chiller and is cooled to start the process over again. This basic concept has been applied in laboratories everywhere to cool, heat, or keep stable temperatures for various products. Now let’s get into the details of specific process cooling systems used in the biotech industry.

Types of Chillers Used in the Biotech Industry

Recirculating Chillers

One type of process cooling used in the biotech industry is recirculating chillers. Recirculating chillers pump water through their systems in order to regulate temperature. The only difference from a basic closed loop system is that recirculating chillers don’t have an internal bath but rather continuously pump water or other fluids through their system. Recirculating chillers are used ideally to cool laboratory equipment -10 to 30°C in 5L. Many recirculating chillers are specifically designed for specific types of laboratory equipment like rotary evaporators, parallel evaporators and extraction products. This is beneficial because these pieces of equipment all must maintain stable temperatures in order to perform correctly. Recirculating chillers allow laboratory equipment to work safely, accuracy, and precisely, and safely.

Immersion Coolers

laboratory immersion chiller — labsociety.com

Another cooling system used in the biotech industry is referred to as immersion coolers. Immersion coolers are used primarily for counter-cooling when connected to a heating circulator. Immersion coolers are also used to rapidly cool fluids down to low temperatures. For laboratories that work with low temperature substances, immersion coolers are perfect. They allow experiements and processess to be carried out at a stable low temperature.

Laboratory Water Bath

Perhaps the most interesting use of process cooling in the biotech industry comes in the form of the laboratory water bath. In this system, a container is filled with heated water. This is used to incubate samples in water at a constant temperature over time. All laboratory water baths have a digital or analog temperature control that allows users to set and maintain their desired temperature. Laboratory water baths are used to warm reagents (reactors in chemical reactions), melt substrates and other substances, or they can be used to incubate cell cultures. Laboratory water baths also allow certain chemical reactions to be more controlled, as they can occur at highly regulated temperatures. Different types of water baths are used for different types of experiments or reactions. For any process occuring in water, the temperature can reach up to 99.9 °C. Anything above 100 °C, would require an alternative fluid to be used like oil, silicone or even sand.

Cooling Chambers

Cooling chambers are used, as you might have guessed it, to cool samples and other substances. Cooling chambers can be used in bakeries to cool entire rooms of bread, and they can be used in chemical storage rooms to ensure safe storage. Cooling chambers allow laboratories to freeze samples, store samples, work with various liquids, and more! This is done through creating a tightly sealed area and using a process cooler to regulate the temperature, as well as using some other chemicals. Cooling chambers use chemicals like nitrogen to allow substances to maintain a colder temperature.

Benchtop Coolers

Benchtop coolers are compact enough to fit on most countertops. Benchtop coolers are used primarily to preserve biological samples. Benchtop coolers can maintain freezing conditions longer which allows these containers to stop reactions, store, and transport temperature sensitive materials. Laboratories use benchtop coolers to minimize enzyme, cell, or reagent loss. Benchtop coolers hold standard tube, and vial sizes. Some feature labelled grids or plates to allow users quick identification. Benchtop coolers use ideas from process cooling to regulate temperature. In many cases, benchtop coolers feature some form of insulation that is able to keep the temperature inside very controlled and very stable.

Cooling from North Slope Chillers

North Slope Chillers offers easy to install, portable chillers that won’t disrupt your current setup. If you would like to know more about our product offerings, give us a call at (866) 826-2993 .