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[adib]

Can u guys help me..?

What's the differences between pump,compressor & expander? I found a little but not much..Heee

& which is better in term of horse power & why is that so? Thank you thank you!

[Art Montemayor]

Adib:

A pump adds work input into a liquid fluid in the form of a positive head, which allows the fluid to be transported.

A compressor adds work input into a gaseous, compressible fluid in the form of a positive head, which allows the fluid to be transported.

An expander is a mechanical device used to "expand" a fluid from a higher pressure to a lower pressure. This, in effect is the opposite action of what a pump or a compressor does. This "expansion" action produces useful shaft work and is usually used in the form of making an electric motor run "backwards" - putting generated electricity back into the main line. An example of this is Boulder Dam that uses a Francis turbine to "expand" a hydrostatic head of water into generated electricity. A gas expander works in a similar mechanical fashion.

A pump and compressor cannot, by pure logic, be compared with an expander as to efficiency. Their type of operation is opposite of each other. A pump can move more liquid mass per unit of energy than a compressor can move a gaseous mass and is more efficient in that respect. That is why it is always more expedient to transport a fluid in the liquid phase than it is in the gaseous phase - if possible.