The principle of Gert Breur's Ram pumps
Gert Breur's water-powered ram-pump also sucks up water!
The well-known ram pump, invented two centuries ago by Montgolfier, can lift water to high altitude using the energy of a larger amount of water falling only a few feet. The Dutch inventor Gert Breur has added only one valve to the original two-valve ram, creating a novel design which can still pump water up, but also sucks water from a lower level into the main drive stream. One possible application for this pump is at a piece of land which is the lowest point around, gathering water and becoming too wet for use. With a stream passing by at a higher level, this ram can be powered to lift the water up from the land into the stream. At the same time the ram can pump up water from the stream to a higher level, for irrigation or drinking. The water pumped up from the lower level is not mixed with the water which is pumped to the higher level, because it enters the ram after the impulse valve. See picture 2 for reference.
Gert Breur has been experimenting with different materials to make
the ram according his design criteria. These are:
- Simple operation, so everyone can grasp the working principle by
looking at the parts and assembling them.
- Construction simplicity, so everyone can assemble one in a matter
of minutes. Maintenance by local people is the goal.
- Easily obtainable materials, no special parts, so independence
from suppliers. Local hardware store or garden centre should
provide most or all material.
- No fees, no royalties. The inventor does not want to earn money,
he wants people to enjoy the availability of clean water, saving
lives and decreasing diseases. Therefore construction drawings
and shopping list are free available, distribution is encouraged.
Common characteristic of all ram pumps is the operation using
hydro power: a running stream or at least a waterlevel difference
is needed. No electric, oil, gas or other energy is needed.
This makes the operational cost very low: only the maintenance.
Since the operating principle is so simple that local people can
maintain the ram, this further reduces opertional cost.
Combined with the use of standard materials for the Breur ram, this
is an ideal choice for developing countries and for the many
environmental aware do-it-yourselfers that want running water at
their residence, but want to use renewable energy to bring it there.
Operation principle of the basic ram pump:
The cycle consists of three phases, see figure 1.
a. Acceleration Phase
Water running through the ram increases in speed until the flow through
the impulse valve causes enough pressure difference to close it.
b. Compression Phase
The moving water causes a high pressure inside the ram, which opens
the delivery valve until the movement of the water has stopped.
c. Recoil Phase
Depending on the type of ram, some air enters the ram during the
recoil of the water, this air adds to the 'pressure bubble' in the
delivery output, smoothing the operation of the ram. Fresh air is
needed if this air can escape during the operation of the ram.
At the end of the cycle the impulse valve is opened by its spring
and a new cycle starts.
Operation principle of Gert Breur's suction ram pump: See figure 2. The same phases as in figure 1 apply for this ram. Additional action occurs in phase b: Compression/Depression Phase. The water that already passed the impulse valve causes a low pressure when it closes (vacuum). This opens the third valve, sucking in a small amount of water until the main water flow has been stopped, so the pressure rises and the third valve closes.
More information on the ram pumps of Gert Breur can be found at the Working Group On Development Techniques (WOT). This is a volunteer organisation of the University Twente, the Netherlands. They are advising developing countries on the use of Renewable Energy, preferably by knowledge transfer of the technology, so local support is guaranteed.
contact address:
WOT
Vrijhof 206
P.O. Box 217
7500 AE Enschede
the Netherlands
tel: +31 53 489 2845
fax: +31 53 489 2671
e-mail: wot@tdg.utwente.nl
http://www.student.utwente.nl/~wot
Last update: April 11, 1999
Webmaster: Cor van de Water
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For more info on Ram pumps, go to the WOT homepages: WOT - Working group on Development Technology.