How Industrial Process Chillers Work

Industrial chillers take the principles behind a home air conditioning system and take it to the next level. These coolers do more than create chilled fluid They can also cool air or a refrigerant. While some industrial chillers are used for air conditioning, others have more specific applications based on the companies using them. From air-cooled chillers to evaporative cooling towers, continue reading to learn more about the industrial chiller selections available to you.

For instance, a petrochemical company may need an industrial process cooling system to keep equipment from overheating, or a food manufacturer may require a cooler for food storage and production. To find the right chiller for your needs, you must know the types of industrial chillers available and their applications:

• What is an industrial chiller?
• How does an industrial chiller work?
• What applications does an industrial chiller have?

Industrial Chiller Definition – What is An Industrial Chiller?

Industrial chillers are refrigeration systems that cool fluids for industrial purposes. The chilled liquid is then used to cool the environment or equipment. Chillers have a multitude of applications as varied as food production and plastics creation, but what all have in common is the use of a unit to cool water or air to chill equipment or a certain area.

What is a Process Chiller?

A process chiller is a cooling system that removes heat created during an industrial process. Process chillers cool a liquid that circulates the area that needs to be cooled, maintaining the set temperature. These conventional systems are different from HVAC chillers in most areas including water circuitry and component integration.

Industrial Chiller Applications

The applications for industrial chillers have a wide range. Pharmaceuticals, food production, petrochemicals, plastic production, metal plating and agriculture are some of the industries that benefit from having industrial chillers for their many manufacturing processes.

What Are Chillers Used For?

Industrial process chillers

are used in a variety of applications:

• Cover Area Cooling: Manufacturing equipment generates a lot of heat. Such a hot environment can be dangerous for employees. A cover area cooling unit can cool the air in a factory, making it safer and more comfortable for the workers. These air-cooling systems also are used for keeping offices and other working spaces cool during warm weather. Rental package units can cool temporary areas without the cost or effort of purchasing and installing a full-sized HVAC system.
• Process Cooling: Industrial processes create heat through friction, equipment or burning. To increase the longevity of the equipment and keep the process running smoothly, you need a process chiller. Unlike standard HVAC systems you have in your home or office, process chillers cool a liquid that circulates the area to be cooled, maintaining a set temperature for larger applications like a school. This liquid may be water, propylene or ethylene glycol, or even something like methanol or ethanol. Since processes are as diverse as petrochemical manufacturing and plastics production, process coolers have many different forms. The cooled liquid circulates equipment to keep it at safe operating temperatures or cool it to a lower temperature for a process.
• Plastic Manufacturing: Plastic is very temperature sensitive. If it gets too hot, plastic can melt. During production, plastics need to cool in molds to an appropriate temperature. Cooling the molds requires a hard-working chiller. For extruded plastics, the formed plastic needs a cooling bath to chill in. A chiller provides the cooling for this bath. For extrusion plastics production, the ideal setup includes a second heat-exchanger to separate the water used for cooling the equipment and the extrusion water. Keeping these waters separated prevents contamination from plastics in the extrusion water.
• Metal Plating and Anodizing: Metal plating can be done with electroplating or electroless plating. Both methods require high temperatures. Anodizing is a similar process to reduce corrosion on non-iron surfaces. It, too, uses high temperatures to electrically bond the finish to the metal. Because both anodizing and metal plating require temperatures ranging in the hundreds of degrees, companies specializing in these processes need a heavy-duty chiller to remove the heat produced from the solution. Some shops solve the problem of heat removal by sending the plating or anodizing liquid to a heat exchanger while others will use glycol or water-containing coils to cool the fluid in the tank.
• Food Processing: The food production industry is the first application many people think of when they list uses for industrial chillers. While most people think of refrigerators, industrial process chillers are also an essential part of this industry. Glycol coolers send chilled propylene glycol through cooling coils for chilling food or beverage storage units. For instance, breweries and wineries frequently use glycol chillers for keeping their products at the perfect temperature. The beverage industry isn’t the only one to use chillers. Food manufacturers use process coolers to chill dough mixers or cool ice cream makers.

Types of Industrial Chillers

Types of chillers used in industries such as petrochemicals and food production include air-cooled and water-cooled. These types of chillers differ in how the refrigerant gives off the heat it absorbs. Each class has its advantages and disadvantages, depending on its use:

• Air-Cooled Chillers: Air-cooled chillers use ambient air to cool the refrigerant. These cooling units have numerous applications. Food processing and plastics use air-cooled chillers to maintain the temperatures of products. Many maintenance personnel prefers air-cooled chillers because they are a stand-alone unit and do not require any additional equipment to function.
• Water-Cooled Chillers: Industrial water chillers require a separate cooling tower to remove heat from the refrigerant. Compared to air-cooled chillers, water-cooled units take up less space, even with the cooling tower. But they do need a sizable water-filled tower that requires a continual water source, which wastes water. This can be a detriment especially in areas with water restrictions.

Beyond the means of cooling the refrigerant, chillers also have several compressor types. Screw and scroll are two different ways of compressing the cooling agent used in the chiller:

• Screw Chillers: Screw chillers come in water-cooled and air-cooled varieties. These use the movement and force of one or two screws to compress the refrigerant inside. Screw chillers come in capacities of 30 to 400+ tons, for everything from heavy-duty to light-duty HVAC applications.
• Scroll Chillers: A set of interlocking scrolls inside the compressor pressurizes the refrigerant in a scroll chiller. Like screw chillers, scroll coolers may be air-cooled or water-cooled. Industrial applications of scroll chillers include everything from drinking fountain coolers to cutting with water jets or lasers. Scroll chillers have capacities even smaller than screw chillers, for cooling of a single piece of equipment. You will find 2 to 140 tons in scroll chiller tonnages.

In addition to specific compressors used with cooling systems, some chillers have particular applications. Two types, explosion-proof and low-temp, are custom chillers used by petrochemical companies. But these types of industrial chillers also have utility in other industries, such as ice rink maintenance and pharmaceutical production:

• Explosion-proof: In highly volatile situations, you want a reliable chiller that won’t be compromised by heavy-duty use. Off-shore oil rigs and petrochemical facilities use explosion-proof chillers for their durable design. We’ve worked with companies such as Dow Chemical, Exxon, Shell and Chevron to provide them with high-quality, reduced risk chillers. All of our XP duty chillers are designed from the ground up to meet the area classification needs and provide the longest life.
• Low-temp: Low-temp chillers reach down to -40 degrees Fahrenheit. These may use either scroll or screw compressors to attain these low temperatures. Scroll compressors can operate down to approximately 0 degrees F versus Screw compressors which are capable of producing down to -40F. While most often these chillers are used in petrochemical cooling and to create the ice for ice skating rinks, they also have other applications. The medical field uses these coolers to manufacture or test various drugs, while the food industry uses the low temperatures for instantly freezing food before storage.

How Do Industrial Chillers Work?

An industrial chiller works on the principle of vapor-compression or vapor absorption By changing the state or pressure of refrigerant in the compressor, evaporator and condenser, the unit is able to cool equipment or an environment. This is a general overview, but we’ll dive in deeper to understand the essential roles each piece of equipment plays in transferring heat from the process away and taking chilled liquid back to the process.

Industrial Chiller Liquid

The first step for any chiller starts with the refrigerant. This chemical holds more heat than water does, which allows for more efficient cooling. The coolant readily changes states from a liquid to a gas as it heats. When the refrigerant cools, it condenses back into a liquid. Switching between these states and from high to low pressure allows the coolant to cool air or water used for a process.

While the refrigerant is the heart of the chiller system, it may not be the liquid that passes through process cooler coils for chilling anodizing or metal plating liquids or food storage. Water or glycol are often used in chiller coils to cool fluid in tanks. (It can be very difficult to regulate the tank temperature when trying to directly run refrigerant through the tank coils. It is not recommended.) To reduce the temperature of the glycol or water, you need an industrial glycol chiller that cools and circulates propylene glycol throughout the system.

Parts of a Process Cooler

Process chiller systems have three main components — compressors, evaporators and condensers. Each changes the state or pressure of the refrigerant during the cooling process:

• Evaporator: The heated refrigerant, having picked up the heat of compression in the compressor, is cooled in the condenser and then passes through the expansion valve (metering device), changing state to low temperature, low pressure. It then enters the evaporator and starts to boil immediately as it cools the process medium. Heat from operation in the evaporator warms the coolant until it turns into a gas. As a low-pressure gas, it needs to raise its pressure, which is where the compressor comes into play.
• Compressor: The gas pressure increases after a trip through the compressor, which physically presses the gas to increase its pressure without changing its state. Now, the hot, pressurized gas needs to release its heat in the condenser.
• Condenser: The condenser may be air-cooled or water-cooled. Air-cooled types use the surrounding air to remove heat from the refrigerant. Water-cooled uses a water cooling tower to store water to cool the refrigerant through means of evaporation. The purpose of the condenser is to remove the heat of compression from the compressor. After giving off its heat, the refrigerant condenses down into a high-pressure liquid, which returns to the evaporator or goes to the process.

Two types of systems exist, open-loop and closed-loop systems. Open-loop systems expose the water to the outside at a cooling tower or large water storage tank. This exposure to the elements can introduce contaminants in the system. Closed-loop systems have the liquid flowing through the pipes in a sealed system with less chance for contamination (Re: Air Cooled Chillers). Closed-loop systems are better suited for smaller applications while open-loop designs are best for large tonnage chiller systems.

Maintenance Tips for Industrial Chillers

Maintaining an industrial chiller keeps it running longer. Regular measurements should be part of the care schedule. Best practices for chiller maintenance include testing water, oil and refrigerant and analyzing vibrations of any rotating equipment. These tests look for any contaminants in the system and inefficiencies, which can shorten the lifespan of the unit. For best results, you may need to partner with a water testing company or a water chemist to ensure proper testing procedures.

While having a designated maintenance crew member to keep up the industrial cooling equipment is ideal, many companies don’t have that luxury. Neglecting expensive, complex industrial cooling units is not an option. Instead, consider a maintenance service, which will take care of any upkeep. You can even get services covered under warranty or aftermarket services. Getting an immediate response for equipment failure helps reduce downtime. A big part of keeping a chiller lasting for the long haul is choosing the best type at the start. We can help you find the perfect chiller for your needs. You can contact our Service Department to discuss our available PM (Parts/Maintenance) contracts available.

Efficiency of Process Coolers

Each state will have different guidelines and requirements for the efficiency of process coolers. California has some of the strictest requirements in the nation for energy efficiency of industrial chillers, as outlined in Title 24 from 2001 — Title 24 is also updated every few years. As efficient as these guidelines are, you can still select components of a system that will allow for even more energy savings. Choosing the most energy-efficient chiller could save you thousands of dollars in energy costs over the lifetime of your equipment. While the study examined HVAC systems, the same principles apply to process coolers. Higher energy efficiency saves you money.

Regardless of where you operate, industrial chillers have become more efficient over time. Older models run less efficiently than newer models. For instance, all our systems adhere to the ASHRAE 90.1 energy efficiency minimum requirements. These standards dictate energy efficiency standards for almost all buildings except small residences and have served as the basis behind worldwide building codes for 35 years. ASHRAE regularly updates these requirements as technology changes.

What Are Chiller Tonnage Requirements?

Tonnage requirements for process coolers require precision. You cannot use an undersized unit. You won’t get the needed cooling level. Oversizing a process chiller is just as bad because it will run inefficiently. You need to know the incoming and outgoing temperatures for your process in addition to the amount of water flowing in gallons per minute. Find the difference in temperatures and multiply by the number of gallons per minute and by 500 to find the tonnage (FOR WATER ONLY):

• tons = 500 x flow rate (gallons/minute) x (incoming temperature – outgoing temperature)

Once you know the tonnage, you might want to add 20 percent to the number if you plan to increase operations soon. Otherwise, use the calculated capacity to purchase an industrial cooler that minimally meets the number. While too much tonnage is wasteful, a little over the required load is better than having an undersized unit that will never attain the cooling you need.

How Much Does a Chiller Cost?

Chiller prices are as varied as the options available. The type of chiller, its tonnage and use all affect the purchase price. Cost factors for chillers include quality, longevity and efficiency in addition to the purchase price. Evaluate these as carefully as you do the price tag to make the best decision.

How Long Do Industrial Chillers Last?

How well you maintain a process, the type of chiller and the materials in its design determine the equipment’s lifespan. Chillers with screw compressors last 20 years compared to only 8-15 for scroll compressors. Air-cooled condensers can last 20 years (when properly maintained), as well, but fiberglass cooling towers can operate up to 35 years. When selecting a process cooling system, consider its lifespan when comparing prices. It will help you make the wisest investment of your money.

Get in Touch With the Industrial Chiller Specialists

Prices for chillers vary widely depending on tonnage and design. Never settle for a chiller not designed for your specific needs to save money. You’ll spend more over time due to inefficiencies in the misuse of the cooler. Choose the right industrial chiller for your needs. How much you pay will depend on if you rent or buy a chiller. To ensure you get the best price, always get a chiller price quote. Contact us today to learn more about our wide range of industrial process cooling solutions and process cooling equipment.