Digital temperature control unit

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Temperature is the key parameter in operations such as chemical synthesis, natural molecule extraction, fermentation, and even biochemical processes.
These process stages take place in a wide variety of equipment—including reactors, reboilers, crystallizers, filter-dryers, dryers, fermenters, and bioreactors—all of which share a common feature: a jacket through which a thermal fluid circulates to control the process temperature.
The successive stages of a batch process are carried out within the same unit at varying temperatures, typically ranging from -20°C to 150°C, though this can extend to +200°C or even -100°C for demanding processes.

Operators have specific requirements regarding:
• Productivity: no time should be lost during temperature transitions.
• Production quality: temperature must be precise and uniform; the product must not overheat upon contact with the vessel wall. The target process temperature must be reached directly, without "overshooting."
• Safety: heat generated by exothermic reactions must be effectively removed.
• Equipment maintenance: repeated injection of steam, water, or brine causes highly damaging corrosion. These are advantageously replaced by a secondary thermal fluid loop known as a "monofluid" system, where the same oxygen-free fluid circulates through the reactor jacket across the entire temperature range.

For many years, CELSIUS has specialized in the design and manufacture of a dedicated unit known as a thermal skid, monofluid skid, or energy module. The "single-fluid" thermal medium is selected based on the temperature range—water, water-glycol, or thermal oil—and is heated or cooled according to process requirements using an on-site utility such as steam, electricity, water, water-glycol, brine, thermal oil, or even liquid nitrogen for cryogenic temperatures. To avoid stresses caused by temperature differentials and fluctuations, the heat exchangers used are of the spiral-wound tube type.

All components required for temperature control—circulation pump, heat exchangers, control valves, shut-off valves, instrumentation, automation systems, etc.—are assembled into a single skid-mounted unit. The unit is delivered to the site fully assembled, piped, insulated, and wired, thereby minimizing installation, connection, and commissioning time at the facility (often a Seveso-classified site).
The energy module is supplied with a CE nameplate and a CE certificate of conformity in accordance with the European Pressure Equipment Directive PED 2014/68/EU and, where applicable, the ATEX Directive 2014/34/EU for equipment used in explosive atmospheres; it also includes an Installation Qualification (IQ) protocol to facilitate FDA equipment validation.

Drawing on extensive experience, CELSIUS possesses the full range of expertise required to design and manufacture this process equipment, which manages the temperature of the reaction mass within the production vessel.

Based on the target mass temperature and readings from temperature probes in both the reactor and the single-fluid loop, the automation system selects the appropriate heat exchanger and controls the shut-off and control valves.
Furthermore, the CELSIUS automation system incorporates a digital twin of the reactor and the energy module. The reactor is modelled based on its operating characteristics—such as the jacket, agitation system, and solvent content. During an operational simulation, temperature values drive the control valves. In turn, valve positions allow for the calculation of fluid velocities, flow characteristics, and heat transfer coefficients within the jacket and heat exchanger; this enables the determination of temperatures inside the reactor and the single-fluid loop for the subsequent time step.
By utilizing the operator's plant parameters, this simulation allows the digital twin of the system—comprising the reactor and energy module—to run for weeks prior to delivery. This facilitates the optimization of control parameters, thereby limiting the commissioning phase to a single day using settings pre-calibrated to actual operating conditions.