difference between pumps?

Question

what is the difference between axial and centrifugal pumps?

Answer 1

With axial pumps, the flow of water is in the direction of the axis of the vane rotor. With centrifugal pumps, the flow of water is throw perpendicular to the axis of the rotor. With the axial pump, both inlet and outlet pipes are inline, with centrifugal pumps, the outlet pipe is at right angles to the inlet pipe, which is how one can easily tell if a pump is axial or centrifugal.

The principle of operation is different. Axial pumps work much like screw propellers used in boats, imagine a screw propeller inside a cylinder, forcing the water to flow through it. Centrifugal pumps work by spinning curved fins which throw the water outwards from the center, where it's collected by a annular space leading to an outlet pipe.

Answer 2

If you have a water pump filter that hangs on the side of the tank you do not need an air pump alhtough I would have both. The water gets oxygen from being circulated. An air pump usually comes with a starter tank along with a air stone. This pump puts oxygen into the water for the fish which should be 1 fish per galllon.

Answer 3

You are almost right but more precisely, mainly there are the differences in following
1) Impeller blade profile. Blade profile force fluid to move in radial or axial direction.
2) Frame in which fluid move during impeller rotation. Axial frame has converging shape while centrifugal frame has envolute/circular shape.
These are the basic defination of AXIAL and CENTRIFUGAL.

There is also a blade profile called "MIXED FLOW" which is basically the combination of Axial and radial flow.
Inlet/Outlet piping also indicates direction of flow. either it is in axial or radial.