Austrian OEM Mirai Intex, which manufacturers ultra-low temperature (ULT) refrigeration systems that use only air (R729) as the refrigerant, has unveiled what it is calling its most powerful machine, the Mirai Cold 80T unit.
The Mirai Cold 80T is capable of providing up to 55kW (15.6TR) of cooling power, more than three times the capacity as the next largest model. The new machine can deliver temperatures from -40°C to -110°C (-40°F to -166°F).
The 80T is a “closed-cycle” ULT machine can be employed for freeze-drying/lyophilization, such as freeze-drying PCR (polymerase chain reaction) tests used to detect the SARS-CoV-2 virus that causes COVID-19. Mira’s open-cycle machines can be used to support COVID-19 vaccine storage.
The new unit’s full name is Mirai Cold 80 C/W/T. The letter combination stands for closed cycle (C), cooled by water (W), and T is for an additional heat exchanger that can cool a secondary medium.
While suitable for any ultra-low-temperature application, closed cycle machines “are designed for process cooling and excel in freeze drying applications,” said Mirai on its website.
Mirai’s ultra-low temperature machines are also used for cryotherapy and freeze drying of pharmaceutical products, and can double as heat pumps.
Other Mirai models
Mirai makes three other closed-cycle ULT models, Mirai Cold 10T (up to 6.5kW/1.8TR capacity), Mirai Cold 15T (up to 9.8kW/2.8TR) and the Mirai Cold 23T (up to 16kW/4.5TR). The company also manufactures three open-cycle ULT machines, Mirai Cold 10, 15 and 22, with cooling capacities of up to 5.4kW/1.5TR, up to 9.5kW/2.7TR and up to 14.3kW/4.1TR, respectively. All units operate oil-free.
The Mirai Cold 80T is equipped with a frequency inverter, enabling “precise” partial load operation, according to Mirai. The unit has compact dimensions for the cooling capacity delivered, and the same low noise levels as its smaller cousins, said the company.
The 80T units also come with “advanced” controllers that enables remote monitoring, and integration of communications protocols like ProfiNET, EtherCAT, EtherNET/IP and Powerlink.
Mirai’s air-cycle technology is based on the heating capability of air during compression and its extreme cooling effect during the expansion process. Repeated compression and expansion cycles can produce temperatures down to -110°C (-166°F) without any need for phase changes.
The core of all Mirai’s products is the so-called turbo module. The module consists of a centrifugal compressor and an expander mounted on opposite ends of the same drive shaft, which is driven by an electric motor. The mounting of the compressor and the expander on the same shaft makes the system up to 30% more efficient than similar systems, said Mirai in a statement. The turbo module uses air-foil bearings, eliminating the need for an oil management system.
