Similar to process cooling, the use of glycol heaters in process heating helps to keep temperatures warm rather than cool. Glycol is an anti freeze chemical that is typically used in cooling and heating loops, which would normally have to be shut down during the winter months due to their pipes being exposed to freezing temperatures. Working similar to how electric water heaters do, a heating element, which is located inside the supply of fluid warms it up to a set temperature. It then switches off when the preset temperature is reached, and then restarts when the fluid needs heating up again.
Keeping heat away from hazards
The dilemma of process heating can be a complicated one, particularly in hazardous locations. In such locations it can be very dangerous to a process that generates masses of heat near a certain material or other process. The use of a glycol heating solution helps to keep the source of the heat a safe distance from the hazard, whilst simultaneously applying heat directly in order to protect the industrial / manufacturing process from any temperatures that are too cold.
Glycol heating solutions
Glycol, along with water and thermal oil are the most commonly used mediums for transferring heat. They are intermediate liquids that are ideal for transferring heat to an end target. This can be anything from a critical material, or process equipment, to storage locations or even other liquids.
With a glycol heating solution temperatures are able to be monitored and maintained at all times. Whether it is glycol heating or even thawing that is required the process will be highly effective due to the use of thermal fluids. Because the end target is never in direct contact with the glycol heater, they are ideal for slower processes that need complete and constant temperature control.
Types of Glycol heaters
These are several types of glycol heaters that are currently available on the market. These are:
- Frost chillers – This type is perfect for manufacturers in light industry that want to experience process heating for the first time. This type is portable so can be used for single application heating. It is able to consistently produce temperatures between 45 – 85 Fahrenheit.
- Freeze chillers – This type is highly powerful and dependable. It has the capacity to consistently produce temperatures between 40 – 75 Fahrenheit at 1.5 – 2 ton, and between 40 – 65 Fahrenheit at 5 – 10 ton. It is a real workhorse that comes equipped with a durable condensing unit and lots of horsepower. The refrigerants used in this are R134A and R404A. The latter is a HFC blend that is commonly used as an alternative to CFC 502. Depending on the exact model, the voltage ranges from 208 – 480 volts.
- Deep Freeze chillers – This type works on an industrial scale and has the ability to consistently produce temperatures between -112 – 70 Fahrenheit. All its internal parts come fully insulated in order to ensure that no temperature is lost internally. It will keep important equipment and materials hot even in the coldest of conditions. The refrigerants used in this chiller are R404A and R508B. These are a HFC blend and commonly used alternatives to CFC 502 and R503 / R13. Depending on the exact model, the voltage ranges from 208 – 480 volts.
- Fluxwrap – Slightly different to those previously mentioned, but a simple and convenient temperature solution nonetheless. It is able to produce both hot and cold liquid circulations to regulate the temperature of equipment and containers, providing a consistent and controlled temperature at all times. It is able to providing heating or chilling to vessels that previously were either too difficult or not financially feasible to heat or chill.
How do they work?
Glycol heaters are categorized into two main types, depending on how they move the refrigerant around their system. These are vapor absorption, which use heat, and vapour compression, which uses an electric drive mechanism. Vapour compression is the most common type used in fluid based heaters, like glycol heaters.
They work by removing heat through the pumping of water, or another fluid, through a condenser and dispersing it through a cooling tower. These chillers are more efficient than air cooled chillers. Thanks to water’s high heat capacity, the process of using water evaporation to dissipate heat is far more energy efficient than blowing hot air across a cold surface. Traditionally, these heaters last longer than air powered heater as well.
The compressor starts the refrigeration cycle and begins so by pushing the refrigerant through to the condenser. During this process the low temperature and low pressure refrigerant is compressed and changed into a high temperature and high pressure gas state. Whilst in the condenser air or water flows over the coils to remove any heat from the refrigerant. The refrigerant condenses at this point as it loses heat and turns into a liquid form. After leaving the condenser, the refrigerant goes through the expansion valve where it is restricted. Once through the valve, the refrigerant goes into the evaporator where it then begins to evaporate back into a gas state. This will then enter the compressor and the entire cycle starts over again.
The types of compressors that glycol heaters utilize are subcategorized into the following:
What are the benefits of a glycol heating solution?
An effective and robust glycol heating solution will be highly efficient in transfer heating, thus allowing for the precise control of temperatures. This will allow for optimized operations as essential equipment and materials will be protected. You can find more information about this system on North Slope Chillers.