Due to its electronegativity and low arc time constant the SF6 gas regains its dielectric strength very rapidly after the final current zero. The ratio of rise of dielectric strength is very high and time constant is very small.
In this the gas is made to flow from a high pressure to a low pressure zone through a convergent divergent nozzle. The mass flow is the function of nozzle throat diameter the pressure ratio and the time of blow. The nozzle is located such that gas flows axially over the arc length. The arc space gets filled with fresh SF6 and well rest is simple.
[This is a 2 minute concept sketch drawn especially for exam point of view.