Propellers and impellers both provide thrust, but do it in different ways.
A propeller is a fan which propels a fluid by pushing against it: it converts rotational motion into linear motion. An impeller is a rotor that produces a sucking force, and is part of a pump. A propeller is always “open” and an impeller is always “closed” (as it has to draw fluid into something).
L-R: Impeller and propeller
I don’t think this is quite right. While in a sense they do much the same thing, the distinction, surely, is in the intent of each:
– An impellor (or impeller – either is correct) is intended to move the fluid. eg a pump impellor.
– A propellor is intended to move whatever the propellor is attached to, eg a boat or aeroplane.
As a general rule the construction of each is different: an impellor usually (but not always) induces radial flow, whereas, for a propellor, radial flow is ideally avoided – it’s just an inefficiency!
An impellor may produce a sucking force, but so does a propellor.
Impellors are usually shrouded to direct the flow in a particular way. Propellors can also be shrouded for greater efficiency.
I think the difference is the shape of them, Impeller is closed, use for industrial Fan, pump that suction one inlet an pushing one outlet direct with high speed, so it need more stiffness. while Propeller is open, more various inlet and one wide outlet direct, use in boats, ships, celling cooling fan …