By comparing the cooling characteristics of four types of cryoprobes under different inlet pressures

the effects of the inlet pressure

J-T slot inner diameter

and backflow channel size on the cooling of cryoprobes are analyzed

and the size of ice hockey balls formed in gelatin are tested. The results show that the temperatures of 1.8–0.42 mm

1.8–0.30 mm

1.8–0.12 mm

and 1.1 mm cryoprobes are the fastest under the inlet pressure of 4.5 MPa

4.0 MPa

5.5 MPa

and 5.5 MPa

respectively. When the pressure is low

the cooling rate is positively correlated with the inlet pressure. When the inlet pressure is greater than the optimal pressure

the ice blockage increases with increasing pressure. Among the cryoprobes

a smaller inner diameter of the J-T slot improves the cooling rate of the cryoprobes and lowers the temperature of the tip

and a larger backflow channel can reduce ice blockage in the pipe and improve the cooling rate; 1.8–0.42

1.8–0.30

1.8–0.12 mm

and 1.1 mm cryoprobes have the largest ice hockey ball diameters under air supply pressures of 4.5

4.5

6.0

and 6.0 MPa

respectively. When the inner diameter of the J-T slot decreases

its optimal air supply pressure increases.