Cryogenic cooling is more and more commonly used. Although the cryogenic technique is still a relatively new field of expertise, many manufacturers discover that production processes become more efficient and significantly faster, and better when performed in extremely cold temperatures.
What exactly are the benefits of cryogenic cooling? This article compares cryogenic cooling with some other cooling methods and explains why cryogenic cooling has become increasingly better known and more popular in recent decades.
What is cryogenic cooling?
Cryogenic cooling is the use of extremely cold temperatures to cool materials quickly and effectively. In most cases, this involves using liquid gases, which at -160 °C or lower, are called “cryogenic temperatures”.
How these very low temperatures are achieved depends mainly on the material that needs to be cooled and the type of gas used. As you can read on our cryogenic technique page, cryogenic temperatures are, among other methods, achieved by conduction, evaporative cooling, cooling by rapid expansion, or adiabatic demagnetization.
The choice for a particular gas also depends on the material to be cooled. Liquid nitrogen is widely used for cooling food, biological materials, and electronic components, while for large research projects and in aerospace, the use of liquid helium is common because of its even stronger cooling capacity.
As we outlined a few weeks ago in our blog on cryopreservation, cryogenic refrigeration has a significant advantage when a product or material needs to be preserved at optimal quality.
For example, when food, biological materials, or medicines are frozen in a “standard” freezer at around -18 °C, the freezing process progresses relatively slowly and unregulated. This causes the formation of ice crystals, which can damage the shape and structure of the product.
Frozen fruit clearly shows this phenomenon. When taken out of a “standard” freezer, both the appearance and the quality are no longer the same.
With food, this does not always have to be a problem, but with medical elements, it certainly is. Hence, cryogenic freezing is a logical solution.
By applying cryogenic freezing techniques, the cooling process is regulated (controlled-rate-freezing). This enables fast and deep freezing while preventing moisture loss and crystal formation as much as possible. Cryogenic freezing limits moisture loss to about 1%, whereas approximately 1.5-2% moisture loss occurs in an IQF tunnel freezer and 4% in a spiral freezer.
A rapid workflow
Next to quality increase, cryogenic gases also accelerate work processes within various industries.
For instance, in the food industry, it regularly happens that production has to be stopped while a product has to cool down, a waste of time that can easily be resolved by using a cryogenic coolant. As an example, a cryogenic tunnel freezer cools down foodstuffs in no time at all, eliminating the need to interrupt the production process.
Cryogenic cooling also saves time in the automotive industry. A well-known cryogenic method in this industry is shrink-fit cooling. In this process, mechanical parts are immersed in a cooling box filled with liquid nitrogen and shrunk to the point where they can then be inserted into, for example, an engine block with minor force. Once the parts return to ambient temperature, they expand again and are thereby firmly anchored. Additional cooling wheels are often placed in the cooling box, giving the part time to cool down without delaying the workflow.
Cryogenic cooling methods also save much time in the manufacturing industry. For example, in the aluminum extrusion industry, liquid nitrogen is used to inert the workspace (as in the electronics industry) and quickly cool aluminum profiles immediately after production. Moreover, cryogenic cooling has also proved to increase the speed and effectiveness of steel production tools.
In conclusion, cryogenic cooling proves to be a very effective cooling method. And the more effective the cooling, the less interruption is caused in the work-flow, and the sooner a project can be completed.
A sustainable alternative
While they differ significantly, cryogenic gases also share a prominent similarity: they are a natural product. For example, nitrogen gas is abundantly present in the air we breathe.
In air separation plants, nitrogen, oxygen, argon, and a tiny number of noble gases are filtered out of the air and separated from each other, after which they can be used in liquid form in cryogenic machining and applications ..
In case gas is discharged after it has been used, it will simply mix with the air again. It is not necessary to collect and filter it as it does not pollute the air.
When used for the cooling of production tools, liquid gas brings an additional sustainability benefit. Cryogenic cooling has demonstrated to reduce tool wear. Better and longer serviceability of equipment reduces waste and pollution.
Probably this benefit already speaks for itself after reading the previous sections. However, we want to mention the financial benefits of cryogenic cooling. When compared to alternative cooling methods, cryogenic cooling has two substantial economic advantages.
First, cryogenic cooling is much faster than most other cooling methods, which obviously saves time. It ensures that processes can continue without waiting time or interruption.
Second, cryogenic systems are often more cost-effective to set up and purchase than known alternatives. Maintenance costs are low as well, and the systems can be cleaned easily and quickly.
In this context, we refer to refrigeration systems that use gases, such as the popular liquid nitrogen. When using a scarcer gas, such as helium, a project can turn out to be a lot more expensive.
However, with the right technology, sustainable and affordable use of scarce liquid gases is also possible. A perfect example is the ASuMED cryogenic engine, which we described in detail in our previous blog. This innovative and superconducting aircraft engine uses helium in, what is known as, a closed loop system. The helium does not leave the system and is continuously circulated and re-used. For more information, check out our blog on the cryogenic engine.
How Demaco makes cryogenic cooling possible
At Demaco, everything revolves around cryogenics. Every day our experienced team is involved in new cryogenic projects and issues within a wide variety of cryogenic industries.
Our vacuum insulated transfer lines, conditioning products (quality enhancing products), and turn-key solutions collectively contribute to the efficient transport, storage, and liquid gas usage. As a result, cryogenic cooling is made safe, sustainable, and effective in a way that perfectly matches our customer’s requirements.