The schematic diagram for HVEF refrigerating system (HRS) is
shown in Figure 1. It mainly consists of a multiple points-to-plate
electrode system, 2 treatment chambers, an incubator, and a highvoltage
power supply (Model Chargemaster CM-60, Taiwan Honlycon,
Inc., Taiwan). The sharp points of 16 needles (0.001 mm in
dia.), which were connected to the negative pole of a high-voltage
power unit, formed the corona discharge electrode. The voltage
can be adjusted from 0 to 60 kV by a controller. The grounded
plane electrode was a 58 × 45 cm rectangle stainless steel plate. A
control with a dummy electrode system was not connected to the
power unit. The 2 treatment chambers were placed in the incubator
for temperature control. The distance (discharge gap) between
the corona electrode and plate electrode was adjustable. The voltage
for the electrode system is 20 kV, the distance between plates is
0.2 m, and the electrostatic field strength is 100 kV/m.