Effect of a Stick on the Gas Turbulence Structure in a Cyclone Separator

Laser Doppler Velocimetry (LDV) was used to measure the turbulence structure of the flow field in a cyclone separator. The measurement results showed that a stick inserted in the cyclone changed the distribution of the flow field. A flow wake region downstream the stick decreased the tangential velocity and increased the turbulence intensity. The size and shape of the stick cross-section had a remarkable effect on the distribution of the flow wake and the turbulence structure of the flow field. The changes of the flow field explained how the stick reduced the pressure drop over the cyclone.

Acknowledgments

This work was supported by National Natural Science Foundation of China (No. 10172055).

Notes

¹All of the stick with rectangular shaped cross-section has the same depth 1 mm.

²In the table above, the pressure drop reduction of the cyclone was calculated based on the drag coefficient. The pressure drop over a cyclone ΔP was often reported as an empirical function of the drag coefficient ξ, gas density ρ and the inlet velocity V_i:

When a stick was inserted in the cyclone, the drag coefficient changed to ξ′, so the pressure drop reduction was: