CHART MVE Fusion, Technical Manual, Page: 14 / 51

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4. The pistons begin withdrawing, and helium then moves back through the
regenerator and aftercooler. Still delayed by its inertia, the gas in the inertance
tube follows, and the cycle begins again.
The heat exchangers and pressure wave generator are cooled by the fans which blow air
over the motor enclosure and main heat rejection core.
3.4 Dewar
Chart is the leading global manufacturer of vacuum insulated biological storage freezers.
Standard Chart MVE freezers use liquid nitrogen as the cooling medium; it boils off as
heat leaks to the outside, which maintains the internal temperature, but requires a
constant replenishing of liquid. This limits installations to areas where LN2 is readily
available and easily transported to each freezer location. The MVE Fusion leverages
Chart’s vast experience and industry leading technology by incorporating these already
proven freezers into a freezer that runs solely on electricity. The only difference is that an
internal cryogen storage pressure vessel is added along with a cryocooler to maintain the
cryogen in a liquid state. The MVE dewar consists of the following major components and
features:

Stainless Steel Construction – All storage and pressure vessel components are
constructed of welded stainless-steel offering decades of service life.

Vacuum Insulation – The annular space around the sample storage compartment
is vacuum insulated to virtually eliminated conduction and convection losses.

Retractable Stairs – Offer safe, easy access to the freezer storage area.

Access Lid with Cork – Light, easily removable lid with magnetic switch that
indicates when the lid has been removed or improperly placed.

Storage Space – The MVE Fusion is designed with a rotating tray, lazy Susan,
which allows access to all samples without difficulty.