PORTABLE SAND FILTER FOR SMALL DRIP IRRIGATION SYSTEMS

Resumo

PORTABLE SAND FILTER FOR SMALL DRIP IRRIGATION SYSTEMS

CLEOMAR FERREIRA DE OLIVEIRA¹; MARCONI BATISTA TEIXEIRA^2*; ADRIANA RAMOS³; RENATO MOREIRA DA SILVA⁴; PEDRO HENRIQUE PINTO RIBEIRO⁵ E JOSÉ ANTÔNIO FRIZZONE⁶

¹ Engenheiro Agrônomo, Prof. Dr. IFMinas Gerais - Campus Muzambinho, MG.

² Engenheiro Agrônomo, Prof. Dr. IFGoiano - Campus Rio Verde, GO. *E-mail: marconibt@gmail.com

³ Engenheira Agrônoma, Profa. Dra. Universidade Estadual de Santa Cruz – Ilhéus, BA.

⁴ Engenheiro Agrônomo, Doutor, Departamento de Engenharia de Biossistemas, LEB - ESALQ/USP, Piracicaba - SP.

⁵ Tecnólogo em Irrigação e Drenagem, Doutorando, Departamento de Engenharia Rural, UNESP/FCA, Botucatu, SP.

⁶ Engenheiro Agrônomo, 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 São Paulo. Magnetic-induction Conaut Krohne model IFS 4000 w/6 with IFC 090 D signal convert of discharge, reading range between 0 and 90 m³.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 m³.h^-1 and 0.556 m³.h^-1, and thus may satisfy small trickle irrigation projects.

Keywords: Filtration, water quality, head loss, flow rate.