How long will Dyson's patent for airflow multiplication expire?

Dyson's patent for airflow multiplication expired in 2009. Dyson's airflow multiplier technology, also known as AirMultiplier technology, is Dyson's unique innovative technology, and its patent expired in 2009. This technology adopts a special airflow design, which releases the surrounding air through the airflow inlet at the bottom of the fuselage and the annular air outlet at the top of the fuselage to form a continuous and uniform airflow, thus realizing the design of the bladeless fan.