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Industrial Water Chiller Systems

Archives for March 2020

Guide to Ultra Low Temperature Chillers

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Reaching New Lows

Ultra low temperature process chilling is a highly specialized branch of refrigeration that has a myriad of industrial uses. From aerospace to food service, many industries benefit from pushing the chilling envelope lower and lower. Let’s explore the world of ultra low temperature process cooling.

download our ultra low temp spec sheet

Ultra Low Temperature Chilling FAQs

What is considered an ultra low temperature?

The ultra low temperature range typically starts at a high of around -40°F (-40°C) and continues to descend from there. Ultra low temperature freezers and chillers can reach a wide variety of low temperatures, depending on the needs of the application.

What are cryogenics?

Cryogenics is the study of ultra low temperatures, how they are created, and how they affect matter. The Encyclopedia Britannica classifies cryogenic temperatures as ranging from -238°F all the way down to -460°F or absolute zero. Absolute zero is the theoretical point where molecular motion is as close as it can get to stopping completely. 

What industries use ultra low temperature chillers?

The uses of industrial low temp chillers are expanding every year. Currently the industries that use ultra low temperatures include: aerospace, medical, pharmaceutical, automotive, defense, plastic manufacturing, chemical, plant oil extraction, food production, and more.

What applications require ultra low temperatures?

Ultra low temperatures are used to: safely store and transport fragile lab samples, temper metals and other materials for extra strength and durability, test materials for use in extreme temperatures/high altitudes/outer space, cool sensitive medical equipment, create superconductors, safely store and transport hazardous chemicals, super chill gasses for plant oil extraction, flash freeze food, and more.

How do ultra low temperature chillers differ from regular chillers?

Regular chillers typically use 1 stage of refrigeration, whereas ultra low temperature chillers can use multiple refrigeration stages. These refrigeration stages can even use different fluids for each stage to reach lower temperature ranges. Ultra low temperature chillers also need more efficient, stronger, and more durable interior components to be able to keep up with the temperature demands. Internal parts (compressor, valves, tubing, pump, etc.) usually need to be upgraded to more robust models for ultra low temperature chilling.

What are the different fluids used in ultra low temperature chillers?

Single stage chillers that operate above freezing temperatures (32°F or 0°C) can use water or deionized water. To increase that cooling range, some single stage or dual stage chillers use a water glycol mix that can achieve even lower temperatures. Below -4° F (-20° C) dual and triple stage chillers can use a variety of heat transfer fluids containing silicone oils, inert fluorinated fluids, hydrofluoroethers, or alkylated aromatic fluids.

What is a recirculating chiller?

Recirculating chillers are closed loop and constantly reuse the refrigerant and process fluids. Heat is either dissipated from the system by forced air or a water cooling tower.

What is a liquid nitrogen chiller?

Liquid nitrogen chillers use containers of supercooled nitrogen that have been chilled enough to change from a gas to a liquid. As opposed to a recirculating chiller (that only expels heat and air), liquid nitrogen chillers expel heat and ventilate gasses. Because the liquid nitrogen is being ventilated, it will need to be replenished, which can make them more expensive to operate than ultra low temperature recirculating chillers. 

What is pull down time?

Pull down time is the amount of time it takes for a chiller to descend from the ambient room temperature to the required chilling temperature. Pull down time is affected by the type and amount of insulation, the type of heat transfer fluid used, as well as the efficiency of the compressor.

What should I look for when buying an ultra low temperature chiller?

An industrial ultra low temperature chiller is only as strong as its weakest link. Let’s expand upon this question more thoroughly…

Selecting an Ultra Low Temperature Chiller: What Do You Need To Know?

There are certain questions you need to ask yourself as you start looking for an ultra low temperature solution.

North Slope Chillers graphic on what you need to know when selecting an ultra low temperature chiller

Cooling Application

The very first step is to make sure you thoroughly understand what process or materials you need chilled. This will determine a lot of the specifications you will look for in an ultra low temperature chiller.

Cooling Capacity and Temperature Range

Ask yourself how low you need to go? Be sure to have a really clear idea of how cold you need your chiller to be. It is typically a good idea to purchase a chiller with a slightly wider temperature range than you think you will need.

Pull Down Time

How quickly do you need your chiller to move from ambient room temperature to your desired temperature targets? Some materials are more forgiving than others as they chill, others need ultra cold and they need it fast. Know your chilling timeline so you can be sure the chiller you select will get cold as quickly as you need it to.

Internal Components

Becoming acquainted with the basic interior components of a chiller will help you foresee and avoid future problems. For example: How loud will the compressor be? Is the fluid reservoir made of a corrosive resistant material? Are the interior components rated to work the heat transfer fluid I need? Acquiring a baseline knowledge of a chiller’s inner workings will increase your success in selecting the right ultra low temperature chiller.  

Chiller Footprint and Dimensions

Industrial ultra low temperature chillers come in all shapes and sizes. Take a thorough look at your layout and where you need a chiller to operate. Look beyond just the size and fit and make sure your chiller’s vents will be unobstructed so it can operate as efficiently as possible.

Duty Cycle

How long do you need your chiller to operate? Does your application need ultra low temperature chilling 24/7? Or does it need to kick in only occasionally to prevent machinery from overheating? Knowing the answer to these questions will help you pick a chiller that is robust enough for your needs.

Power Usage

For safety and financial reasons, it is extremely helpful to know how much power your chiller will use. This will help you avoid overloading whatever circuit you plug it into. Contact your power company and find out how many cents you will be charged per kilowatt hour in your area. That way you can avoid surprises on your bill after you start using your chiller. 

Indoor or Outdoor Rated

Not all ultra low temperature chillers are rated for both outdoor and indoor use. Make sure you know exactly where your chiller will be operating so you can make sure you purchase one that matches its environment.

Heat Transfer Fluid(s) Type

There are a wide variety of heat transfer fluids that can be used to reach ultra low temperatures. Some chillers can have multiple refrigeration stages and use a different fluid or oil in each stage. Do your research on what fluids will help your chiller reach your desired temperature ranges.

Temperature Controls

Thermostatic controls have come a long way in a short period of time. How much control do you want over your chiller? Some ultra low temperature chillers will come with basic controls that require someone to physically input information. Others may come with smart control options that allow you to remotely take control over your temperatures no matter where you are. Would you like to tap into the internet of things and have access to process cooling data analytics?  Be sure to look at all of your options and find the solution that will not only fit your budget but will give you the most autonomy and peace of mind.

North Slope Chillers Ultra Low Temperature Solutions

Here at North Slope Chillers, we know that one size does not fit all. We are proud to offer the most thorough and quickest customized process cooling options on the market. Instead of searching endlessly for the right chiller, or compromising on some of your requirements, why not custom design the exact ultra low temperature solution you need?

By working with our world class team of engineers you can make sure you find an ultra low temperature chiller that is designed for your exact cooling requirements.

North Slope Chillers graphic on ultra low temperature process cooling

Contact us today to find the perfect ultra low temperature cooling solution for your needs at (866) 826-2993 or [email protected]

Ultra Low Temperature Process Cooling

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How Low Can You Go?

Our modern lives, as we know them, would be very different without process cooling. Many of the products we use, buy, wear, and eat, rely heavily on precise temperature control at different stages of their manufacturing and transportation processes. But what do manufacturers do when their products require exposure to extreme temperature environments? Let’s take a closer look at ultra low-temperature process cooling, who needs it, and why.

download our ultra low temp spec sheet

 Why Go So Low?

There are many reasons why certain industries need process cooling equipment to reach ultra-low temperatures. One of the most common uses of ultra-low temp chilling is for durability testing. 

Durability Testing For Extreme Environments

Take a look around you. As most of us sit in our comfortably climate controlled homes, offices, and vehicles, it can be hard to imagine how the products around us would react to extremely cold temperatures. At what point would they stop working…crack…explode…rupture? Most of the items around you would never naturally reach those temperatures, so there is little reason to worry. Everyday items undergo typical durability testing to make sure they can operate safely and efficiently in a wide range of seasonal environments. 

However, materials and devices that are intended to operate in the upper atmosphere, deep ocean, or outer space must undergo more rigorous testing. In order to be prepared for anything mother nature can throw at them, every piece of equipment, protective gear, machinery, electronics, and other supplies need to be thoroughly tested before they can be safely used in such an environment.  

North Slope Chillers graphics on ultra low temperatures in nature

Land

The lowest temperature ever recorded at Earth’s ground level occurred on July 21, 1983. The Soviet run Vostok Station in Antarctica recorded a temperature reading of -128.6° F (-89.2° C). More recently, satellites have detected even lower readings (some as low as -144° F), but the 1983 record is still recognized as the most accurate reading from the ground level. 

Sea

Similarly, the coldest seawater temperature was also recorded in Antarctica. A super salinated stream of seawater running under an Antarctic glacier measured in at 27.3° F. The high salt content allowed the water to reach sub-freezing temperatures and still remain liquid. 

Atmosphere

Another natural extreme temperature environment exists above us at all times. The Earth’s atmosphere is comprised of multiple layers, and each has different environmental conditions. The mesosphere is the layer that extends from 31-53 miles above the Earth’s surface. The top of the mesosphere (aka the mesopause) is the coldest section of our atmosphere and has an average temperature of -130° F. 

Space

For the most extreme temperatures, we have to look beyond our home planet. According to NASA, gaseous matter out in space routinely drops to -454° F. Because of the extremely cold conditions in space, astronauts will soon be able to conduct quantum cooling experiments in the Cold Atom Laboratory (CAL) on the International Space Station (ISS). There, astronauts will be able to use quantum process cooling to chill atoms well below the average temperature of deep space, boldly going where no thermometer has gone before. 

Cryogenics

Another common need for ultra-low temperature process cooling lies in the vast field of cryogenics. Broadly speaking, cryogenics is the study of ultra-low temperatures and how matter behaves at those temperatures. According to the Encyclopedia Britannica, cryogenic temperatures range from -238°F all the way down to -460°F or absolute zero. Absolute zero is theoretically the point where molecular motion is as close as it can get to stopping completely. Over the years, many different cryogenic sub-studies have evolved in our modern world.

North Slope Chillers graphic on the types of cryogenics

Cryobiology – studying the effect of ultra-low temperatures on organisms

Cryonics/Cryoconservation/Cryopreservation – conserving genetic material and organisms for future revival

Cryoelectronics – the study of electricity at ultra-low temperatures

Cryosurgery – using cryogenic temperatures to medically destroy harmful tissues or growths 

Materials behave very differently when exposed to cryogenic temperatures. Some, like rubber, become so brittle they are easily broken down. Others, like ceramics and some metals, become superconductive and allow electricity to flow through them with zero resistance.

What Industries Use Ultra-Low Temperatures?

The field of cryogenic and ultra-low temperature process cooling is expanding every year. As we continue to find new ways of utilizing this technology, the possibilities seem endless. Let’s look at some specific examples of industrial uses for ultra-low temperature process cooling.

North Slope Chillers graphic on the industries that use ultra low temperature process cooling

Aerospace

The aerospace industry must rigorously test every component used in modern aircraft for its ability to withstand extreme temperature changes. Ultra-low temperatures can increase wear and in compromise the structural integrity of many kinds of materials. These aeronautic materials undergo what is known as cryogenic tempering to increase their durability. They are exposed to strategic high and ultra-low temperatures during fabrication so their microstructure becomes more stable, durable, and long lasting. Cryogenic processing is used to improve the performance and strength of engine components, turbine blades, seals, brake lines, and more.

Pharmaceuticals/Medical

Medical and pharmaceutical laboratories use ultra-low temperature freezers and storage rooms to preserve important samples. These can include: bone marrow, blood, stem cells, vaccines, DNA and RNA, Sperm, Eggs, Embryos, and more. Many of these samples are extremely valuable and some are irreplaceable. Ultra-low temperature storage and transportation is absolutely crucial to protect the viability of delicate lab products. 

Pharmaceutical companies also use ultra-low temps for the lyophilization (freeze-drying) process. Lab samples are inserted into a special ultra-cold vacuum chamber that freezes and removes moisture simultaneously.

In addition, some medical devices, like MRI machines (which require cryogenic cooling temps of -400° F) need ultra-low temperature process cooling in order to operate safely.

Food Service

If you have ever purchased frozen seafood in a landlocked state, then your taste buds have benefitted from ultra-low temperature process cooling. Commonly referred to as “flash freezing”, food products can be frozen so quickly, they don’t expand or lose taste or nutritional value. Flash freezing also preserves natural flavors so your food still tastes fresh and delicious. 

Automotive

Similar to the aerospace industry, the automotive industry tests structural and engine components for usability in extreme temperatures. Testing a car in ultra-low temperatures allows car manufacturers to see if fluids and batteries hold up, electronics still function, how quickly the engine and cabin heat up, and to what degree the vehicle is still operable. 

Defense

Civilians like us will never know all the ways the defense industry uses ultra-low and cryogenic temperatures. However, looking closely at the private sector we can see many ways the defense industry can benefit from ultra-low process cooling. As mentioned above, aerospace engineers subject every material used on an aircraft to thorough temperature testing. Ultra-low temperatures are also useful for storing and transporting flammables and combustible materials safely. Cryogenic tempering is also used on a wide variety of metals (including on firearms) to strengthen their microstructure and increase durability. 

Chemical

Storing and transporting temperature sensitive chemicals can be extremely dangerous. Many flammable and combustible materials require ultra-low temperature solutions in order to meet hazardous location safety certifications.

Plant Oil Extraction

Extracting highly pure oils out of plant matter involves some ultra cold temperatures. Some companies use CO2 extraction methods that use carbon dioxide which is chilled below -69° F. Some companies also use ultra-low temperatures (-20°F) to remove natural waxes from their extracts. These extraction methods produce high concentration oils that are very valuable. In recent years, the production and use of essential oils, especially CBD oil, has grown into a very lucrative industry. 

Plastics

Plastic injection molding is a highly efficient plastic manufacturing method that greatly reduces waste material. Special thermoplastics (such as ABS and Polyethylene) are heated, injected into a mold and then quickly chilled before they are released from the mold. Molding plastics at high temperatures creates a nice glossy finish and makes the finished plastic more heat resistant. Rapidly chilling then makes the plastic stronger and more impact resistant.

North Slope Chillers Ultra-Low Temperature Solutions

North Slope Chillers graphic on deep freeze ultra low temperature chillers

Here at North Slope Chillers, we specialize in portable and powerful industrial process cooling. Our Deep Freeze line features a wide temperature range from -112° F to 70° F. With fully insulated interior components, Deep Freeze operates efficiently with little thermal loss. If you need a liquid cooling system that is both reliable and as cold as it gets, look to Deep Freeze. Contact us today to find the perfect ultra-low temperature solutions for your needs at (866) 826-2993 or [email protected]

The Fabric of Our Lives: Plastic

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Plastic Injection Molding Touches Our Lives Every Day

Products created by plastic injection molding are all around us, from water bottles to the button on your shirt. This process is efficient and can create products that are very large heavy-duty to products that are tiny and delicate. This article explores the top level of all there is to know about the plastic injection molding process.

Learn more about Plastic Injection Molding

Let’s Learn about Plastic Injection Molding

*Note to reader:  American English has no mould, and British English has no mold. In other words, the word referring to (1) the various funguses that grow on organic matter or (2) a frame for shaping something is spelled the same in both uses, and the spelling depends on the variety of English.  For the purposes of this article regarding plastic manufacturing, I will be using the American English version.

Standard  household items, produced every day, are the result of injection molding. The applications cover commercial, industrial, and consumer products. Because of injection molding manufacturing, companies can design products that are intricate, versatile, and complex, and also range from very small to large objects.  

This method has produced solid parts such as electronic housings, bottle caps, containers, computers, televisions components, outdoor furniture, agricultural products, toys, machinery components, and much more.

We Use It:  Common Products Made with Plastic Injection Molding   

Plastic bottles are the most common product manufactured by the billions each year.  Plastic bottles are made from polyethylene terephthalate (PET), because the material is both strong and light.

Electronic housings used in devices such as remote controls, computers, televisions, medical equipment, and other consumer electronic components, are all produced by injection molding process. 

Toys: Toys need to be lightweight, durable, and corrosion-free.  Lego is a perfect example of an injection mold toy. A firmer plastic granule is heated until liquified and then injected into metal molds.  After cooling, that heated plastic becomes one of the world’s favorite toys. Lego is a precision product that must fit together perfectly–manufacturing must be perfectly executed.  

Quick List of All the Places We Find Injection Molding Products

Automotive:

  • Color-matched Interior Components

Commercial Construction:

  • Conduits for Concrete Beams
  • Insulators
  • Raised Flooring Panels

Residential Construction:

  • Roofing Vents
  • Railing Gaskets
  • Deck Fasteners
Commercial Products:
  • Electrical Boxes
  • Mop Heads 
  • High-end Trash and Recycling Receptacles 
  • Vending Machine Components 
  • Equipment Housings 

Consumer Goods:

  • Skateboard Storage Racks
  • Barbecue Accessory
  • Bird Feeder
  • Tackle Boxes
  • Toilet Seats

Food Service:

  • High-Temperature Serving Pans
  • Bread Trays
  • NSF Food Service Products

Home Products:

  • Flower Pots
  • Wire Ties
  • Air Freshener Units

Medical Components: 

  • Sharps Disposal Bins and Wall Mounts
  • Medication Trays

Toys and Hobbies:

  • High-end Collectible Models
  • Decorated Children’s Furniture

POP (Point of Purchase):

  • Spring-loaded Supermarket Display Tray
  • Literature Display Rack

Sporting Goods:

  • Training Device
  • Exercise Tools

Short-Run 3D Printed Components:

  • Electrical Knobs
  • Specialty Buttons
  • Fixtures

Good to Know

First, the Mold

Injection molds must have a high precision match between the two mold halves in order to perfectly control the material flow. Creating the mold is crucial to building a seamless, precision product.  Injection molds are typically constructed using steel or aluminum, and precision machined to form the features of desired product.  

The mold must be:

  1. Sturdy and able to withstand the pressure involved during injection.
  2. Made of materials that the polymer will properly flow along.
  3. Carefully designed to allow heat transfer to control the cooling process.

Over and Over

Once a funcional and errorless mold is produced, the injection molding process is fairly repetitive. It also has a low scrap rate (percentage of failed assemblies or material that cannot be repaired or restored, and is therefore condemned and discarded) relative to other manufacturing processes. 

Advantages

Repetition and reliable high volume production is the signature advantage of this process. Once the first part is produced, the second is going to be practically identical.  Other advantages are the wide range of material selection, low labor costs, minimal scrap losses, and few requirements for post-molding finishing operations. 

Disadvantages

The major disadvantage of injection molding is the initial cost of the mold design, which tends to be high due to design, testing, and tooling requirements and the longer required lead times. Some custom complex parts may encounter problems during the injection molding process such as warpage or surface defects. Therefore, injection molded parts must be designed with careful consideration to any change in geometry as they cool and the material selection to ensure stability.

The Injection Molding Process

Injection moulding involves a high pressure injection of a polymer into a mold where it is shaped. The individual parts of this process are very short. The whole injection molding process usually lasts from 2 seconds to 2 minutes, and is yet, highly complicated.  There are four stages in the cycle. To watch an excellent animated video on the Injection Molding Process CLICK HERE.

Clamping

Before the mold is injected with material, both halves must be closed. The clamping unit takes care of this. Both halves (the cavity and the core) are then secured in the tool.  Material is then injected as the clamping unit pushes the halves together and both halves are held tightly while material is injected. Larger machines (machines with more clamping power) take longer to close and clamp the mold.

Injection

A hopper feeds plastic pellets into the injection mold machine.  Heat and pressure melt the pellets and help the transformed plastic move through the injection unit. The volume of injected material is called the ‘shot’. Injection is complete when 95%-99% or the mold is filled.  It is hard to calculate exactly the injection time because the flow of the plastic is always changing and dynamic. Injection time can be estimated by other factors such as injection pressure, power and shot volume.

Cooling

Cooling is when the plastic within the mold hardens.  This process begins as soon as the plastic makes contact with the interior mold.  During cooling, the part may shrink slightly. The mold should not be opened until cooling is complete.  Cooling times are estimated based upon the wall thickness of the mold and the thermodynamic properties of the plastic.

Ejection

Now, the product must be removed.  An ejection system is used because force is required to remove the product.  The product will shrink and stick to the mold. Once removed, the mold is shut, and the process begins again. 

Injection Mold Manufacturing Machines

The machines are differentiated by the type of driving systems they use: hydraulic, electrical, or hybrid.

Hydraulic

Hydraulic presses, until 1983, were the only option available to molders.  Hydraulic machines, although not nearly as precise, are the predominant type in most of the world.  These systems use hydraulic cylinders that clamp the mold halves together, with enough force that the mold will remain shut and sealed during injection – between three and four tons of clamp force per square inch are generally required–sometimes more. Modern hydraulic injection molding clamps can exceed 8,000 tons of pressure, allowing them to create parts in excess of 50 pounds.

Advantages:
  • Higher clamping force for large parts, plus larger shot size
  • Resistance to wear and tear
  • Excellent injection rates and ejection capabilities
  • Lower initial purchase price
  • Low cost and great availability for replacement parts
  • Gas accumulators available to help account for slower clamp movements
Disadvantages:
  • High energy consumption, even while idle
  • Higher required molding temperatures and therefore longer cooling times

Electric

In 1984 an all-electric injection molding machine was introduced in Japan – it took a bit of time, but these systems are now popular all over the world.  The electric press, also known as Electric Machine Technology (EMT), reduces operation costs by cutting energy consumption. Electric presses have a reputation for being quieter, faster, and having higher accuracy, however electric machines are more expensive.

These systems utilize digitally-controlled servo motors for their power rather than hydraulics, meaning that they can bring faster and more repeatable processes with more precision and efficiency. Once you pinpoint a given process within your system, it can be replicated consistently with ease, allowing for the creation of bulk projects for a variety of major industrial applications. These systems can also run unattended, which lowers labor costs.

Advantages:
  • Precision and ease of repetition, along with low scrap rates
  • Lower down time than hydraulics
  • Cleaner processes with no fluid leaks
  • Major energy savings
  • Less noise and faster operation with a shorter startup time
  • Lower unit cost and less material waste
  • Lower power requirements that lead to lower operating costs
Disadvantage:
  • Cannot achieve the clamping force of a hydraulic system

Hybrid Systems

Hybrid injection molding machines (sometimes referred to as “Servo-Hydraulic”) are meant to combine the benefits of hydraulics and electrical systems. These systems have the high clamping force of hydraulics, and combine that with the precision, energy savings and reduced noise associated with electrical systems.

Advantages:
  • Electrified screw rotation that limits screw recovery needs
  • Diversity in product design capability
  • Reasonable costs (lower than electric, higher than hydraulic)
  • Continuous adjustments by the servo pump
  • Closed loop processes with a faster response time
  • Lower temperatures required for limited cooling times and extended machine life

Hybrid machines are used for a variety of wall thickness needs, including heavy industrial projects.

Injection Mold Process Cooling

There are two main reasons for using a chiller for the injection mold cooling process. 

  1. Protect Equipment:  While the chiller represents a small cost of the processing equipment, it provides solid protection of your investment, 24 hours a day, 7 days a week for years and years to come.
  2. Increase Production: Maintaining a constant and proper cooling temperature in equipment will increase the number of parts produced per hour, and a significant reduction in the number of defective parts.

Cooling  is a critical stage in the process; over 80% of the total plastic manufacturing process is devoted to cooling. An injection molding chiller will drastically reduce the cooling time and preserve the quality of your products.

North Slope Chillers industrial liquid coolers are the best way to consistently and efficiently maintain life of your equipment and the quality of your plastic parts while also reducing your production time.

Contact us to find the right temperature control solution for your needs:

Learn more about plastic injection molding

(866) 826-2993 [email protected]