Submersible Pumps - Airlift
Airlift pumps are a simple means of moving fluids and have been in use for many years. Recent developments have taken this principle to a whole new level.
The Air lift principle has been around for many years. In fact it was first conceived in 1797 by the German engineer Carl Emanuel Löscher and is one of the most simple and basic ways to pump water and other fluids. Not only is the principle simple, there is not much to go wrong.
Air can be simply injected into the bottom of a pipe and it mixes with the water, reducing the specific gravity and pushing it up the pipe.
Although the principle is great and simple, traditionally there have been limitations. If pumping water, pumps had to be submersed around ½ of the total lift height (eg. If vertical lift was to be 50ft above the water surface, the pump had to be submersed at least 50ft below the water surface) and efficiency was low.
The advantages of airlift pumps were and still are –
1. ease of installation,
2. no potentially troublesome electrical components down in the water
3. No electric or other power required at the pump site – compressed air can be easily piped over long distances
4. Absence of tight tolerances and mechanical components that will wear out with the presence of particulate matter, making airlift pumps ideal for pumping dirty water and cleaning out bores/wells
5. easy to remove, as they are usually light and any water inside either drains back or can be blown out with the air flowing.
Air pressure required is a result of submersion depth in fluid and vertical lift. In most cases a regular, small compressor will be sufficient.
Flow can be adjusted by changing submersion depth of the pump in the fluid and altering the air flow to the pump.
Water is delivered in spurts at low pressure, so needs to pump to some kind of open-to-atmosphere vessel, tank or dam. It is not suited for pressure tanks or closed systems.
More advantages of airlift pumps are that compressed air can be easily produced by many means.
As a simple compressor can be used, this can be turned by electric motor (mains or solar), gas or diesel engine, windmill or even human power. Anything can turn a compressor to produce compressed air for the pump, making Airlift a very simple and versatile system and easily adaptable for renewable energy.
There are now pumps available using the airlift principle, that have been optimised and designed to substantially increase efficiency and operating parameters. It is no longer necessary to have 50/50 submersion/lift ratios. The ratio can be down to 30/70 and in some cases with the use of specially designed pump chambers and controllers, submersion in fluid can be as little as 1m (3ft) with lifts of over 100m (300ft) vertical.
Recent further development of airlift pumps has substantially opened them up to a range of applications. They can and are being successfully used with great results in wells, bores, landfills (leachate), mining (de-watering), dams, lakes, rivers and more.
For more information, please see http://www.brumbypumps.com
Source: Free Articles from ArticlesFactory.com
ABOUT THE AUTHOR
Tom Kress worked in the oil and gas industry for many years, has been been dealing with a variety of pumps and had to deal with many pumping challenges.
He designed a pumping system utilising mainly the old and simple airlift principle to overcome issues faced in many situations.