Backgound
This page is going to contain the documentation for my Engr 305 appropriate technology class project. The project is to build a working model of the Pulser pump. There is little documentation of how the thing actually works so the mission of my project is to provide said information in a manner that allows other people to re-create the pulser pump.
As an engineering student this is an opportunity for me to practice the design process, it is also an opportunity to experiment with a technology that is not widely used. If my project results in an accessible and variably applicable model for the pulser pump, it will be able to turn large flow in relatively flat waterways into head that can be used for irrigation, Microhydro, and stored for a myriad of other uses. These pumps could be revolutionary in that they require little to no maintenance and are relatively simple to construct. I will be carrying out my experimentation in Arcata California.
Literature Review
The Trompe
The trompe, sometimes spelled trombe, is a mechanism for drawing mixing air with water and pressurizing the air. A tube of varying length is installed perpendicular to the surface of water with its opening just below the surface. This arrangement causes water and air to be alternately pulled down into the tube, first the water by gravity then air by the vacuum created when a small amount of water descends into the tube. The switch happens when the water immediately surrounding the pipe entrance flows in, because the surface height there takes time to equalize back up to the surface height of the rest of the water. When the mixture of water and air descends down the pipe the air becomes pressurized by the weight of the water. (Hunt 2010)
Criteria
Criterion
Educational Value
Level of Embedded Energy
Functionality
Cost
Weight
Versatility
The Air Lift Pump
When air is mixed with water under pressure it wants to expand; given a small enough outlet water can be pushed up said outlet by the expansion of that air. This mechanism is called Two-Phase Flow, and it drives the air lift pump. (Stepanoff 1965)
General mechanics of head and flow
Head
When a fluid is elevated, it has a gravitational potential energy. This potential is called head.It is typically measure in meters or feet of height, as the distance from the source to where it is being deposited is the dimension in which the mass of the fluid is being acted upon by gravity. (Sullivan 1975)
Flow
Flow is a measure of volume with respect to time. It is often measured in gallons per minute, though any measure of volume per time is suitable. (Graffman 2010)
The Pulser Pump
Brian White has built a pump that is the union of a trompe and an air lift pump. It uses the trompe to take flow in a stream and pressurize air in the water in a chamber below, this pressurized air then pushes a small amount of the water up though a smaller outtake to a higher elevation than the top of the trompe. (White 2008)
References
Sullivan, J. A. (1975) “Head and Pressure”
Fluid Power: Theory and Applications p. 58,59
Reston Publishing Company, Inc. Reston, Virginia 22090
Cheremisiniff, N. P. (1981) “properties of fluids”,”principles of fluid flow”
Fluid Flow: Pumps, Pipes and Channels p. 43-47, 163-166
Ann Arbor Science Publishers Inc. , Ann Arbor, Michigan 48106
Stepanoff, A. J. (1965) “flow of gas-liquid mixtures”
Pumps and Blowers, Two Phase Flow p 275-280
John Wiley & Sons, Inc.
Hunt, J. R. (2010) “Harness Hydro Power with a Trompe”
Mother Earth News , 02/13/10
Lonny Graffman (2010) “general mechanics of flow and head” Personal Correspondence
White, B. (2008) “Pulser Pump” Appropedia, 02/7/10