MICROFICHE REFERENCE LIBFUUW - Cd3wd.com
MICROFICHE REFERENCE LIBFUUW - Cd3wd.com MICROFICHE REFERENCE LIBFUUW - Cd3wd.com
142efficiencies usually range from 35-40 percent with lower breast works to60-65 percent for higher breast works.A rather simple, easy-to-construct version of the breast wheel is theflutter-wheel (Figure 5.6~) which is powered partially as an undershotwheel, i.e., impulse of flowing water, and partially as a breast wheel,i.e., weight of falling water. Although little information is availableon this simple mill, it would appear to have much the same performance andapplications features as a breast wheel if the paddles extend to the hub--unlike Figure 5.6~ (see Rogers, 1905, Vol. 2, p.121). This design couldbe well suited to many developing areas with very light industry.Overshot wheels can obtain some of the best efficiencies (60-85%)of the watermills which can be constructed of wood and/or metal with onlylow to medium technology. They are normally used when heads (H) of 10to 30 ft are available. When used with a sluice gate, as in Figure 5.7, thepower applied to the wheel is a result of both the impulse of the highvelocitywater from under the gate and the weight of the water fallingwithin the wheel. The driving flow must enter the wheel at or beyondthe vertical centerline to avoid the reverse moments encountered withbreast wheels.When heads higher than about 15 ft and some medium industry areavailable, higher efficiencies (80-90%) can be obtained by utilizing watermillswhich are commonly called turbines. Due to the high pressures andvelocities involved in a turbine’s operation, they are made almostentirely of metal. Turbines are normally utilized to drive electricgenerators, however, with the proper transmission, turbines can be usedto drive rotodynamic and rotary pumps.
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- Page 97 and 98: SE;vlI - ROTARYBUCKET VANEU’C)Fig
- Page 99 and 100: 92(a)AIRCHAMBERAIR FEEDERVALVEWASTE
- Page 101 and 102: 94Table 3.8Ram performanceA. Typica
- Page 103 and 104: COMPRESSEDAIRDEAofpctI5LT1EDUCTC II
- Page 105 and 106: 98FLASHTANK .iJI 10 -NON-RETURNVALV
- Page 107 and 108: Because the components are not yet
- Page 109 and 110: 102air-lift pumps. The oscillation
- Page 111 and 112: 104and from the impeller and confin
- Page 113 and 114: 106making this type pump useful for
- Page 115 and 116: 90s; 80iTi!g 700E 60W50SPECIFIC SPE
- Page 117 and 118: 110to lubricate all or some of thei
- Page 119 and 120: 112such variables as impeller size,
- Page 121 and 122: 114GEAR HEADOR IVE SHAFTTO PRIME MO
- Page 123 and 124: 116W(clFigure 4.6 (a) Thai-style ou
- Page 125 and 126: 118DRIVINGSUCTIONDIFFUSERa- - =tQ,E
- Page 127 and 128: DISCHARGELINE OISCHARGE RETURNLINEL
- Page 129 and 130: -122which at $.20/kg, cost $6.00. H
- Page 131 and 132: Table 5.1Manual power appl icat i a
- Page 133 and 134: 126water lifting device. Animals ar
- Page 135 and 136: 1285.4.1 WindWindmills are currentl
- Page 137 and 138: 130even saw use on the windy plains
- Page 139 and 140: 172HAL F CYLINDERSt------TO WATER L
- Page 141 and 142: 135a vertical shaft, the wind will
- Page 143 and 144: --Table 5.3 Typical winchnil 1 clpp
- Page 145 and 146: Table 5.4 Typical watermill applica
- Page 147: 141MEDIUM BREASTFigure 5.6 (a) Medi
- Page 151 and 152: 145-H-f -- WH---@II
- Page 153 and 154: 147with a 330,250 gpd capacity. Bat
- Page 155 and 156: 149Where electric power is not econ
- Page 157 and 158: 151electricity), the amount of use
- Page 159 and 160: 153of building and installing the d
- Page 161 and 162: 155II 300‘0083ooLoo93oo‘ootr000
- Page 163 and 164: 157Example G .l (after Molenaar, 19
- Page 165 and 166: LOW LIFT VERTICAL PUA /lPI------PER
- Page 167 and 168: Chapter 7Improvements and Research
- Page 169 and 170: 163example for further projects (Fa
- Page 171 and 172: 165Reynolds (1970) writes, " . ..ma
- Page 173 and 174: 16?BIBLIOGKAPlIYAddison, Ii., Ccntr
- Page 175 and 176: 169Committee on Water Supply Engine
- Page 177 and 178: Gatz, C. A., Johnston Vertical Pump
- Page 179 and 180: 173Mother Earth News,1574.Ilandbook
- Page 181 and 182: 175Reynolds, I. II. , “High Duty
- Page 183 and 184: 177Svcndsen, M., "Irrigation Techno
- Page 185 and 186: 179APPENDIX
- Page 187 and 188: Tabic;: A.2 Area conversions and ab
- Page 189 and 190: Table A.4 Pressure conversions and
- Page 191 and 192: Table A.6 Discharge conversions and
- Page 193 and 194: Table'A.8 Specific speed (N,) conve
- Page 195: ABHPDD- area- brake horsepower- dia
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