MICROFICHE REFERENCE LIBFUUW - Cd3wd.com

Table 3.4Persian wheel performanceLift(ft)Discharge(cfh) Reference Remarks30 325 Molenaar, 1956 ? hpsome metal parts20 395 Molenaar, 1956 ? hpsome metal parts10 580 Molenaar, 1956 ? hpsome metal parts5 760 Molenaar, 1956 ? hpsome metal parts25 510 Roberts and Singh, 1951 2 bullocksmetal bearingsIslamic Water-Lifting Wheels (1973) gives some excellent details of theconstruction of Persian wheels and other wheel devices, e.g., gears,bearings, fasteners, etc.A modified version of the Persian wheel is the zawafa or Egyptianjhallar. Most zawafas today are constructed entirely of metal, althoughoriginal designs were wooden. Rather than each bucket dumping water intothe same central trough within the driving wheel diameter, troughs betweenthe spokes of the driving wheel receive the dumped water and channel it toa common trough alongside the wheel. In this way a stronger, double-rimwheel can be utilized for deep, heavy lifts or where all metal constructionis used, and the water need not be lifted much above the desired upperwater elevation. Table 3.5 gives some typical performance data of metalzawafas.