Air Lift Pump

It is a device used to lift water from a well or sump by using compressed air

Inventor name:  Carl Emanuel Löscher  in 1797

How it works:

In this, a compressor transfers compressed air at the bottom of the delivery tube that is inside the well or sump. This cause compressed air to mix with the liquid which makes air-water mixture thus reducing the density of the liquid in the delivery tube less than the rest of the liquid outside, around which flow the water upwards through the delivery tube

Uses :

1. In a coffee percolator, the airlift principle is used to circulate the coffee.
2. this pump commonly where the water contains  a mixture of mud that can damage conventional pump as this method does not have any contact with liquid so they can work well in this kind of conditions
3. Used to collect fauna element from sediments

Advantages :

1. It has no moving parts (less chance of part damage)
2. The liquid is not in contact with any mechanical parts so there is no chance of abrasion in the pump or in the pipe
3. This pump can give more water through a given pipe diameter than any other pump 

Disadvantage :

1. Low efficiency 20 %to 40%
2. High running cost. (high pressure is required to get a moderate  amount of water pressure increasing motor electricity cost)
3. Suitable for low head water well or sump