MICROFICHE REFERENCE LIBFUUW - Cd3wd.com

78noria and the discharge and head it must supply need to be matched to theavailable water source is velocity and the paddle surface area. If forinstance, the small paddles in Figure 3.21a do not afford enough surfacearea to receive the necessary momentum of the water flow, then the sizeof the paddles may have to be increased--possibly utilizing a design morelike Figure 3.21b. fro alternatives to increasing paddle size (whichincreases weight and therefore friction) are; (a) increase the watersupply's velocity by decreasing its channels's cross-sectional area as wasdone with the sluice gate and narrowed channel for the paddle-wheel (seeSection 3.3.1.1.), or (b) supply a fall (i.e., head) for the water sourceso that it can power the noria as an undershot wheel (see Section 5.1).Of course, a separate driving wheel (i.e., water mill) can be placed apartfrom the noria (e.g., in a swifter width of the river) and connected to itby a horizontal shaft, as would be done for other typzs of drivers, e.g.,Figure 3.22.A few other common modifications to the noria which are utilized toimprove efficiency and/or adapt it to a given installation include:(a) Use of deep, small diameter containers as in Figure 3.2.a todecrease spillage.(b) Use of movable buckets, e.g., Figure 3.21c, to allow completefilling (i.e., as opposed to fixed containers which fill at anincline--see Figure 3.21a, Insert A) and prevent emptying untiithe bucket reaches tlte upper leveltrough.(c) An enclosed noria with compartments built into it and appropriateinlets and outlets utilizes practically the entire wheel circum-ference and width for increased capacity, e.g., Figure 3.22. The