|A Training Manual in Conducting a Workshop in the Design, Construction, Operation, Maintenance and Repair of Hydrams (Peace Corps, 1981, 216 p.)|
In 1772, John Whitehurst developed the first known machine to utilize the water hammer effect to pump water. Whitehurst's device included a water supply tank, a 1½ inch, 600 foot long drive pipe, a check valve, an accumulator and a delivery pipe. He used a hand-operated impulse valve, employing child labor to open and close the valve in continuous cycles.
In 1776, Joseph Michael de Montgolfier invented a similar machine but replaced the hand operated valve with an automatic impulse valve which was opened and closed by the rebound wave inside the hydram itself. Montgolfier's machine was called "le belier hydraulique," from which the term "hydraulic ram" was derived. (Because "hydraulic ram" can have more than one meaning, however, we prefer the British term "hydram" to describe these water pumping devices, and will use this term throughout this manual.) The invention was so simple and reliable, it has survived over 200 years with very little change.
The technical information contained in this manual has been developed through experiments and experience. We have tried to present the fruits of our experience in such a manner as to be easily transferred to other situations and application The transfer cannot always be complete, however, and situations cannot always be predicted. The performance of a hydram is dependent on many variables. The information contained in this manual should therefore be regarded as guidelines based on past experience, rather than absolute rules.
Perennial Energy, Inc.