Special report: Temperature control

Maintaining the
cold chain

Sébastien Fritsch Maintenance Technician, Facilities & Utilities, Lingolsheim, France

Ensuring refrigeration and optimal temperature control throughout the process.

I am responsible for the cold chain throughout production – from the raw materials to the storage of intermediates and finished products. My role is to ensure that all refrigeration equipment remains available and in optimal operating condition. As cold temperatures are ubiquitous in our manufacturing processes, I can be found almost everywhere around the manufacturing site. There is no place for errors in our industry and every day the equipment for which I have responsibility is under constant surveillance by recordings, alarms, preventive visits and predictive analyses. The control and mastery of temperature at all steps of the process is essential to ensure product quality.

We have a multitude of equipment which is often complex and increasingly regulated, especially in relation to environmental impact. All of our installations use the mechanical compression of a refrigerant gas, generally a hydrofluorocarbon (HFC), which produces cold by expansion or evaporation, similar to what happens when you agitate a spray can. The principle is basically the same as that used by the air conditioning of your car or your refrigerator at home, but due to the power and application needed, the installation quickly becomes akin to a gas plant.

There are many temperature requirements for the storage of plasma, cryoprecipitate, intermediates, finished products, as well as during the transformation phases themselves (centrifugation, fractionation, stirring, filtration, cryoprecipitate-freezing and lyophilisation). There are so called “cold groups” of small, medium and higher power for very diverse applications, from air conditioning offices to maintaining temperatures of storage rooms and freezers. For example, -5°C for the air conditioning of the production premises; -25°C for fractionation tanks; -65°C for lyophilisers; -70°C for the freezing of some finished products, and for the storage of cryoprecipitate. All temperatures are continuously monitored and recorded digitally. The temperature sensors are calibrated and checked according to a schedule established by the maintenance plans.


Monitoring of freeze-drier cooling units.

My role also involves following maintenance contracts in place on certain equipment, anticipating possible problems and settling them as quickly as possible so that there is no impact on maintaining the required cold chain. Such an interruption would in some cases have serious consequences for ongoing processes, intermediates or finished products in cold rooms. My typical daily activities are the control of the equipment, its operation, being able to observe a drift which can announce a future problem and follow-up of the suppliers as part of preventive maintenance. I also perform investigations during deviations to find the cause of malfunctions. The computerised maintenance management system (CMMS) is a tool that allows us to ensure the operational and regulatory monitoring of equipment (breakdowns, curative maintenance, preventive maintenance, leak detection, hydraulic testing). We inform the CMMS with each intervention. The system constitutes the electronic logbook of each piece of equipment.

During a potential power outage, all the technical resources of the plant are mobilised to restart everything as soon as possible and check that the outage had no impact on work in progress. Fortunately, this is very rare.

What fascinates me the most is the operation of the cold groups and the production of heat or cold by the change of state of the HFCs. I love to control the various parameters of an installation, to optimise them and thus be able to observe my impact on the efficiency of the installations. I also enjoy researching the cause of any deviations or the source of recurring problems.

I never miss an opportunity to laugh with my colleagues and friends. I like being active. I like sports in general, swimming, mountain biking, football and the outdoors.

Temperature control

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