Spiral groove dry gas seal (S-DGS)

one of the typical non-contacting surface seals

has been widely applied to shaft-end seals of moderate or high speed turbomachinery. Current status of DGS research and development was summarized on spiral grooves and grooves with different types of molded lines. Structures of derived spiral grooves were systematically analyzed for the purpose of improving film stability

sealing performance

anti-abrasion

and hydrophobic behavior under different operating conditions. Based on their functional characteristics

these derived structures were classified into four types

namely

stability-increased at high speed

leakage-reduced at high speed

stability-increased at low speed

and hydrophobic wear-resistant. Future development would still focus on further improvement of gas film stability and sealing performance at high speed and pressure

quick opening characteristics and gas film stability at low speed and pressure

as well as biomimic design of super hydrophobic and strong wear-resisting seal surfaces. These areas will be critical to expand applications

to enhance reliability

and to extend service life of DGS in the future.