I haven't ever seen a revolving cover on a chimney. Most chimney covers are there to prevent birds and other wildlife from setting up households in the chimney, smoking out the people and possibly, causing a fire.
There are wind-driven ventilation systems that are used on roofs, and possibly that is what you are thinking of.
Because it revolves.
a chimney in Scotland is called a " lumb". Dont ask me why............!
A smoky odor in your room could be due to poor ventilation, a blockage in the chimney, or a build-up of soot and creosote. When the chimney does not draw properly, it can cause smoke and odors to enter the room instead of being carried outside. Regular cleaning and maintenance of the chimney can help prevent these issues.
A windmill is an example of a structure with revolving vanes.
I think it's called chimney cleaner.
A ships chimney is a funnel or stack.
The buildup of soot and creosote from the chimney is often referred to as chimney residue or chimney deposits. This residue can be a fire hazard and should be regularly cleaned to maintain a safe and efficient chimney.
The chimney thingy is called a smoke stack.
The visible smoke coming out of a chimney is typically called chimney smoke or chimney emissions. It is produced when a substance is burned in the fireplace or stove and consists of small particles and gases.
Turnstiles!
A rapidly revolving item is called a "spinning" object. Examples include a spinning top, carousel, or rotating blade.
Do you mean a lightning rod? Our chimney has a vented metal cap on it instead, designed in the 1950s to also keep nuclear bomb fallout from going down the chimney (BTW it would also keep Santa out... ha ha).