Micro-Computed Tomography (µCT) Study of Clogging in Long-Used Strip and Cylindrical Drip Emitters

October 28, 2022

Venkata Ramamohan Ramachandrula (1), Ramamohan Reddy Kasa (2), Arun Torris (3)
Journal of the Institution of Engineers (India): Series A. (28 October 2022). DOI: https://doi.org/10.1007/s40030-022-00697-3


Strip emitters, cylindrical emitters, emitter clogging, emitter geometry


Two sets of samples, having four strip-type and four cylindrical-type emitters, were collected from farmlands after eight years of continuous use. In each set, two are head-end and two more are tail-end samples, chosen randomly across the lateral pipes. The undisturbed clogging patterns on the surface of the sample emitters were scanned and analysed using µCT equipment. The two types of emitters have trapezoidal labyrinth flow path, though their length, cross-sectional area, and dent spacing differ. The clogging material deposition pattern on three functional areas—the inlet, labyrinth path and outlets—was analysed. In case of strip emitters, all the three functional areas are affected by clogging. The lone outlet hole in all the strip emitters got blocked by large-sized deposits of clogging material, which may affect the water flow and restrict the delivery of water. In case of cylindrical emitters, the deposition of clogging material is mostly on the outlet areas in a spread-out manner. More number of dents accommodated in a unit length of labyrinth path coupled with narrower width facilitated the desired pressure dissipation in strip emitters. The longer labyrinth of cylindrical emitters with larger sectional area and dent spacing is less prone to clogging. Design of strip emitters incorporating longer but wider labyrinth path and multiple outlets for distributed flow is suggested for reduced clogging material deposition.

How Our Software Was Used

Dragonfly was used to segment the clogging material deposits from other components. The clogging material was segmented using the intensity thresholding method and features of a typical trapezoidal labyrinth flow path were measured with Dragonfly.

Author Affiliation

(1) Water and Livelihoods Foundation, 12-13-451, Street No. 1, Tarnaka, Secunderabad, Telangana, 500017, India
(2) CVR College of Engineering, Ibrahimpatnam, Ranga Reddy District, Telangana, 501506, India
(3) Polymer Science and Engineering Division, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, Maharashtra, 411008, India