Effect of skin indentation on heat transfer during cryogen spray cooling

2004 ◽  
Vol 34 (2) ◽  
pp. 155-163 ◽  
Author(s):  
Brooke Basinger ◽  
Guillermo Aguilar ◽  
J. Stuart Nelson
Keyword(s):  
Heat Transfer ◽  
Spray Cooling ◽  
Cryogen Spray Cooling ◽  
Skin Indentation

scholarly journals Radial and temporal variations in surface heat transfer during cryogen spray cooling

2005 ◽  
Vol 50 (2) ◽  
pp. 387-397 ◽  
Author(s):  
Walfre Franco ◽  
Jie Liu ◽  
Guo-Xiang Wang ◽  
J Stuart Nelson ◽  
Guillermo Aguilar
Keyword(s):  
Heat Transfer ◽  
Spray Cooling ◽  
Temporal Variations ◽  
Surface Heat ◽  
Surface Heat Transfer ◽  
Cryogen Spray Cooling

scholarly journals Effect of spurt duration on the heat transfer dynamics during cryogen spray cooling

2003 ◽  
Vol 48 (14) ◽  
pp. 2169-2181 ◽  
Author(s):  
Guillermo Aguilar ◽  
Guo-Xiang Wang ◽  
J Stuart Nelson
Keyword(s):  
Heat Transfer ◽  
Spray Cooling ◽  
Cryogen Spray Cooling

Effect of Nozzle Size on the Surface Heat Transfer Dynamics during Cryogen Spray Cooling in Dermatologic Laser Surgery

2012 ◽  
Vol 39 (3) ◽  
pp. 0303005
Author(s):  
周致富 Zhou Zhifu ◽  
王锐 Wang Rui ◽  
王国祥 Wang Guoxiang ◽  
郭烈锦 Guo Liejin ◽  
陈斌 Chen Bin ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Laser Surgery ◽  
Spray Cooling ◽  
Surface Heat ◽  
Surface Heat Transfer ◽  
Nozzle Size ◽  
Cryogen Spray Cooling

scholarly journals Heat-transfer dynamics during cryogen spray cooling of substrate at different initial temperatures

2004 ◽  
Vol 49 (23) ◽  
pp. 5295-5308 ◽  
Author(s):  
Wangcun Jia ◽  
Guillermo Aguilar ◽  
Guo-Xiang Wang ◽  
J Stuart Nelson
Keyword(s):  
Heat Transfer ◽  
Spray Cooling ◽  
Cryogen Spray Cooling

Dynamic Behavior of Cryogen Spray Cooling: Effect of Spray Distance

2003 ◽  
Author(s):  
G.-X. Wang ◽  
G. Aguilar ◽  
J. S. Nelson
Keyword(s):  
Heat Transfer ◽  
Skin Surface ◽  
Spray Cooling ◽  
Heat Fluxes ◽  
Cooling Effect ◽  
Dermatologic Surgery ◽  
Measured Temperature ◽  
Surface Cooling ◽  
Spray Distance ◽  
Cryogen Spray Cooling

Cryogen spray cooling (CSC) is used to minimize the risk of epidermal damage during laser dermatologic surgery. During CSC, skin surface is cooled by a short spurt of refrigerant R134a with boiling point of −26.2°C. Since R134a is volatile in open atmospheric conditions, the atomized liquid droplets undergo continuous evaporation as they fly in air, leading to a lost momentum and mass. Therefore, the cooling effect of CSC depends strongly on the spray distance between the nozzle and the skin surface (L). The objective of this study was, therefore, to investigate the effect of L on the dynamic heat transfer of CSC. A skin model system made of poly methyl-methacrylate resin (Plexiglass®) is used to simulate CSC during laser dermatologic surgery. A fast-response temperature measurement sensor is built using thin (20 μm) aluminum foil and placed on top of the plexiglass with a 50 μm bead diameter thermocouple positioned in between. Variation of the surface temperature is then measured under various spray distances. The surface heat flux (q) as well as the heat transfer coefficient (h) between the surface and the cryogen is estimated by solving an inverse heat conduction problem with the measured temperature data as input. The effect of L on surface cooling in CSC is then investigated systematically. Both the estimated q and h show strong dynamic characteristics and are strong functions of the L. Two distinct spray-surface interaction mechanisms are identified within the spray distances studied. For short L (< 30 mm), the spurt droplets impinge on the substrate violently, resulting in a fairly thin cryogen film deposited on the surface. Strong dynamics and high q result in this case, corresponding to a high h as well. Interestingly, h becomes strongly fluctuating and even larger after spurt termination for these cases. For long L (> 30 mm), q is lower and it steadily decreases after spurt termination. The dynamic variation of h in this case is similar to that of q. These results should help in the selection of optimal CSC parameters, which are needed to produce high heat fluxes at the skin surface and thus obtain maximal epidermal protection during various dermatologic laser therapies.

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