A pneumatic ejector is used primarily to lift water from low points. What device accomplishes this?

A pneumatic ejector primarily operates by using air pressure to lift water from low points, making an air compressor the correct device for this function. The air compressor generates the necessary pressure to force air into the ejector, creating a vacuum that facilitates the lifting of water. This method relies on the principle of air pressure pushing against the water to lift it, making it effective for situations where traditional pumping methods may not be feasible due to height differences or the need for quick drainage.

In comparison, other devices such as pumps are designed to move liquids more directly rather than relying on pneumatic principles, vacuum systems utilize suction but do not achieve the same effect as the pneumatic ejector, and gravity feeders depend on gravitational force rather than mechanical means to move water. Therefore, the unique mechanism of the pneumatic ejector operated by an air compressor is indispensable for effectively lifting water from lower elevations.