Gases for Life


Rapid cooling with additional benefits

By the Editorial Team

Precise cooling is vitally important in a large number of industrial processes. Liquid nitrogen and the CryoControl process let you achieve the right temperature quickly and efficiently.

Industrial cooling units basically work like ordinary refrigerators: a coolant is alternately compressed and expanded, thereby extracting heat from it until the right temperature has been reached. This coolant is then conveyed to a chemical synthesis reactor, for example, from where it makes its way back to the compressor in a closed circuit, to be compressed again – and so on. However, this takes time, and the motorized compressor requires regular maintenance. By contrast, liquid nitrogen provides a cold source that is available immediately, without the need for high-maintenance electromechanical equipment. Where a refrigerating machine takes hours to achieve the necessary cooling effect, nitrogen can often perform the same task in just a few minutes with the CryoControl process.

First cooling, then inerting The CryoControl process involves the circulation of a liquid coolant that changes its temperature but not its state. The circulating liquid is cooled with liquid nitrogen at minus 196 degrees Celsius without it freezing. The nitrogen evaporates during this process and is then available for other applications such as inerting tanks filled with sensitive or explosive substances. Incidentally, the cooling circuit can also be used for heating – some processes require an alternation of heating and cooling. In heating mode, the nitrogen supply is simply interrupted, and a heating element switched on. CryoControl is often used for precise and efficient temperature control in chemical reactors. Some synthesis steps, particularly where fine and special chemicals are concerned, require temperatures below minus 100 degrees Celsius. But the system is extremely flexible and can also be used for tasks in other areas and in combination with different cooling media.

Cryocontrol – a wide range of applications Dyneon is a subsidiary of technology group 3M. At the company’s site in Burgkirchen, Bavaria, a refrigerating machine, which is used to cool a condenser in a storage vessel, had to be given an overhaul. The cooling medium flow – in this case ethanol – has a temperature of minus 80 degrees Celsius, with a refrigeration output of approximately 2.5 kilowatts. A CryoControl unit provided a temporary cooling solution, ensuring that the overhaul could take place without interrupting the process. The unit had first been prepared and fully tested at Messer’s technical test center.

DSM Nutritional Products France are based in Village Neuf, Alsace, and produce a range of products including vitamins and carotenoids. Cooling and nitrogen are required in various production processes. This year, the company is using CryoControl for two tasks: the cooling medium, a solvent, is partially cooled with liquid nitrogen. A refrigeration output of approximately 20 kilowatts is transferred to the cooling circuit, and this reduces the power consumption of the refrigerating machine. The vaporized gas is introduced into various processes. The CryoControl system also serves as a backup: when cooling demand is at above-average levels, nitrogen is again used to provide an additional refrigeration output of around 70 kilowatts. Hungarian pharmaceutical manufacturer Richter Gedeon uses the CryoControl unit to cool a reactor at its plant in Dorog to minus 50 degrees Celsius. Syltherm XLT is used as a cooling medium here. The unit’s maximum refrigeration output is 50 kilowatts.