Author(s): Huanfang Liu; Jun Wang; Quanli Zong; Xinlin Li; Jiouying Hu
Linked Author(s): Jun Wang
Keywords: Filter; Microirrigation; Sediment; Local head loss; Clogging
Abstract: Promotion of microirrigation technology in arid area of northwest China has great significance to local economic development and the improvement of water environment. However, almost all the headwaters are highly turbid water in irrigated areas in provinces of Gansu, Ningxia and Xinjiang. In order to guarantee water quality criteria for microirrigation, the highly turbid water must be deposited and filtered. Filter is the key equipment to obtain clear water in the headwork of microirrigation. Based on experiment of hydraulic performances of a hydrocyclonic strainer-type filter using pressure sensor, flowmeter, figure instrument and converter, this paper analyzes the various influences to local head loss by the filter which were caused by distinct degree clogging in its screen. Two empirical equations were established for calculating the local head loss of filter. A special flow mechanism inside the filter element is established, based on which the influences of flow velocity and pressure difference on sediment movement and plugging action of filter element were analyzed. For the same water quality condition as for the ordinary strainer, the new filter wasa found to be able to keep sediment particles in suspension and away from the screen because of its special hydrocyclonic effect, thus resulting in excellent performance, and its filter element can be flushed naturally by tangential flow and keep clean longer than ordinary strainer-type filter. Less backflushing frequency and thrift labor force will be needed and water will be save to some extend.
Year: 2004