On the Distribution of Sprinkled Water from the Turning Perforated Pipe. (Part II)
1971 Volume 33 Issue 3 Pages 257-263
Details
1971 Volume 33 Issue 3 Pages 257-263
In this paper, the desirable operating method and the driving unit of the turning perforated pipe are discusssed theoretically and experimentally, from the viewpoint of uniform distibution of sprinkled water when it is used under the condition shown in Fig, 1.
The results obtained are as follows:
1. For the sector-type driving unit shown in Fig. 4, the volume of sprinkled water directly below pipe is quite much and it decreases with an increment of distance toward the outer zone of sprinkling area. This distribution of sprinkled water can be obtained theoretically by the equation (7).
2. For the bar-type driving unit, almost uniform distribution of sprinkled water can be obtained in the sprinkled area which the range of turning angle is below 110°, however, in the range which the turning angle is more than that, the volume of sprinkled water becomes greatly much at outer zone of sprinkled area. The volume of sprinkled water can be determined approximately from the equation (11).
3. In the case of condition shown in Fig. 1 (a), the bar-type driving unit is better for obtaining the uniform distribution of sprinkled water, but for this driving unit the height of pipe and the pressure of water should be determined so that whole area can be covered when the range of turning angle of pipe is less than 110°.
4. For the case shown in Fig. 1 (b), in which the path is in the center of greenhouse and water is sprinkled both sides, using the perforated pipe with double row orifices and an included angle of 80°, most uniform distribution of sprinkled water can be obtained when the range of turning angle is nearly 45°.
5. The sprinkling intensity is apt to become excessive for both cases, because the sprinkling width in the direction perpendicular to the pipe is too narrow. If the distance between each orifice is 40cm, the sprinkling intensity is approximately 20 to 30mm/hr when (the diameters of orifices are 1mmφ and 1.5mmφ for the sprinkling width of 2m and 5m respectively)
6. Water pressure in this sprinkling device is. about 1.0 atm. Therefore, in the case of small scale irrigation and cheap water rate, the use of simplified water works or service water are desirable for saving the expense of power.
