The Study on Internal Flow Characteristics of Disc Filter under Different Working Condition

Abstract

A disc filter (DF) is an important component in a micro irrigation system. However, it has a high head loss and low filtration efficiency, which can lead to the inoperability of micro irrigation systems. To improve the filtration ability and to decrease the pressure loss of the irrigation system, it is necessary to internalize the hydraulic characteristics of DFs. In this study, the filter bed of a DF was divided into three parts, i.e., upper, middle, and lower, which were wrapped with a transparent film. The wrapped part was completely blocked. The purpose was to analyze the hydraulic characteristics of different clogged conditions in three types of filters under four types of flows. In addition, we attempted to simulate the filter operation process with computational fluid dynamics, based on two aspects—a macroscopic model and a simplified model. The results showed that the patterns of head loss among all of the DFs was consistent, and the macroscopic model that treated filter bed as a porous medium could express the measured results. The macroscopic models observed that there was a circular flow in the DF, and the flow velocity presented a symmetrical distribution in a horizontal direction. The middle of the filter element appeared in a high-pressure area and demonstrated the highest head loss, which may be the main flow area of the DF, and the inner flow characteristics of the DF were consistent under different conditions. The simplified models showed that the main flow area is near the filter bed in the inner DF, and the flow is tangent to the filter bed between 45 and 90 degrees in a horizontal direction. The uneven distribution of velocity and pressure on the filter bed might be necessary factors to impact filter efficiency.

A Standardized Treatment Model for Head Loss of Farmland Filters Based on Interaction Factors

“…Although numerous studies have explored the factors influencing filter performance, few have comprehensively considered the interactions among multiple factors [27][28][29][30][31]. By introducing interaction terms, this study not only unveils the complex relationships The different combinations of lines in Figure 11 represent different optimal solutions obtained by adjusting parameters through model algorithms when applying the response surface method.…”

“…Although numerous studies have explored the factors influencing filter performance, few have comprehensively considered the interactions among multiple factors [27][28][29][30][31]. By introducing interaction terms, this study not only unveils the complex relationships among these factors but also enhances the predictive accuracy of the model.…”

Performance Evaluation of Micro-Irrigation Systems in Coconut Plantations

“…A high head loss and low filtration efficiency resulting from an uncleaned filter may cause a reduction in the performance of the MIS. (Chi et al, 2021). According to Fernando et al (2020) the most common problem reported by the farmers for MIS usage in coconut plantations was frequent line breakdown and the regular examination of lines for damages.…”