MICROFICHE REFERENCE LIBFUUW - Cd3wd.com

663.3.1 WheelAfter many of the early reciprocating devices were developed, it waseventually discovered that by mounting several of them on a wheel, a more.continuous flow could be obtained, i.e., less time waiting to return theone (or two) lifter(s) back to the water supply. The first device to bediscussed is a good example of thisdevelopment.3.3.1.1 Paddle-WheelThis wheel type device utilizes the basic idea of lifting waterby scooping it, just as was done with the water balance (Figure 3.11) .However, instead on one scoop or paddle moving back and forth, severalpaddles are attached to the periphery of a wheel and by rotating the wheel,each paddle pushes a unitof wa:~r up a channel.A typical small-capacity, paddle-wheel is shown in Figure 3.17,operating with manual power. In this example, the operator “pedals” thetips of the paddles, however in other versions, the axis of the wheel isattached to a shaft which can then be turned (often via gearing) by someother prime mover, e.g., a windmill, an animal-powered circular sweep,etc. The device shown in Figure 3.17 has widespread use in low liftapplications such as rice paddies. In order to minimize losses, a woodenchannel is usually provided for the paddle-wheel to rotate inside of.With such a channel, Molenaar (1956) reports the performance of varioussize paddle-wheels as given in Table 3.2.Paddle-wheels are also commonly referred to as paddle-pumps, chackrams(India), kharbauwys, flash-wheels, and scoop-wheels, however, the lattertwo names usually infer large wheels of the size and design used withhigh-power, mechanical drivers. Such sroop-wheels were used extensivelyin low-lying areas, such as Holland, around the turn of the 20th century.