SIMPLIFIED ANALYSIS AND DESIGN OF THE HYDRAULIC RAM PUMP

Hydraulic ram pumps are currently of interest because they make use of a renewable energy resource and are environmentally friendly. Ram pum ps are particularly appropriate for use in the developing world as the ir construction is basic and robust and they are inexpensive and easy to install and maintain. Numerous attempts to analyse the complex beha viour of a ram pump system have been made in the past, but few have be en successfully translated into simple design procedures and none have resulted in a general method for a ram pump of any size. The analytic al approach adopted in the present paper assumes constant friction los s in the drive pipe during acceleration and concentrates on zero recoi l conditions at which optimum pump performance occurs. Four simple and general design equations are derived which incorporate conservative a ssumptions for the critical velocity in the drive pipe and the effect of system losses. Design examples are given and design predictions com pared with new and existing test results. Conclusions are drawn regard ing the relevance of traditional drive pipe length-drive pipe diameter (L/D) and drive pipe length-supply head (L/H) ratios.