PORTABLE SAND FILTER FOR SMALL DRIP IRRIGATION SYSTEMS

PORTABLE SAND FILTER FOR SMALL DRIP IRRIGATION SYSTEMS CLEOMAR FERREIRA DE OLIVEIRA 1 ; MARCONI BATISTA TEIXEIRA 2* ; ADRIANA RAMOS 3 ; RENATO MOREIRA DA SILVA 4 ; PEDRO HENRIQUE PINTO RIBEIRO 5 E JOSE ANTONIO FRIZZONE 6 1 Engenheiro Agronomo, Prof. Dr. IFMinas Gerais - Campus Muzambinho, MG. 2 Engenheiro Agronomo, Prof. Dr. IFGoiano - Campus Rio Verde, GO. *E-mail: marconibt@gmail.com 3 Engenheira Agronoma, Profa. Dra. Universidade Estadual de Santa Cruz – Ilheus, BA. 4 Engenheiro Agronomo, Doutor, Departamento de Engenharia de Biossistemas, LEB - ESALQ/USP, Piracicaba - SP. 5 Tecnologo em Irrigacao e Drenagem, Doutorando, Departamento de Engenharia Rural, UNESP/FCA, Botucatu, SP. 6 Engenheiro Agronomo, Prof. Titular, Departamento de Engenharia de Biossistemas, LEB - ESALQ/USP, Piracicaba - SP. 1 ABSTRACT Filters in drip irrigation systems are fundamental to ensure effective control of water quality and to reduce clogging of emitters. Current study aims at constructing a low cost portable sand filter for small localized irrigation systems (up to 1.0 ha) and at determining its head loss due to flow. Tests were carried out in the Hydraulic Laboratory of Biosystems Engineering Department of Agriculture School “Luiz de Queiroz”, University of Sao Paulo. Magnetic-induction Conaut Krohne model IFS 4000 w/6 with IFC 090 D signal convert of discharge, reading range between 0 and 90 m 3 .h -1 and 99% precision, was used for flow rate measurements. Pressure loss at each observation point was determined indirectly by two differential pressure gauges with a mercury column. A set of 20 flow readings was performed in three replications. Results showed that maximum filter discharge complied with ASAE guidelines and the cost of materials for manufacture of the filter was U$ 382.15. Linear mathematical model adequately describes the loss of pressure of the sand filter due to flow variation. Rates of minimum and maximum flow recommended range between 0.0257 m 3 .h -1 and 0.556 m 3 .h -1 , and thus may satisfy small trickle irrigation projects. Keywords: Filtration, water quality, head loss, flow rate.