PROCEDIMIENTO Y DISPOSITIVO DE FILTRACION

EN UNA INSTALACION DE FILTRO PARA CONCENTRACION DE LECHE ACIDIFICADA EXISTE UNA UNIDAD DE FILTRO ENTRE UNA BOMBA Y UNA VALVULA DE CONTRAPRESION. COMO BOMBA SE UTILIZA UNA BOMBA DE EXPULSION, AUNQUE EL LIQUIDO A FILTRAR ADMITIRIA SEGUN SU VALOR DE VISCOSIDAD UNA BOMBA ROTATORIA INTRODUCIDA A LA MANERA HABITUAL. DURANTE UN PERIODO PAULATINAMENTE LA CONTRAPRESION DE MODO QUE A PESAR DE LA CRECIENTE OCUPACION DEL FILTRO CON COMPONENTES SUSPENDIDOS, DISUELTOS O EMULSIONADOS SE MANTIENE LA PERMEABILIDAD DEL FILTRO. GRACIAS A LAS CARACTERISTICAS DE LA BOMBA DE EXPULSION SE MANTIENE LA CANTIDAD NECESARIA A PESAR DE LA CRECIENTE CONTRAPRESION, DE MODO QUE EL EFECTO DE LIMPIEZA DEL LIQUIDO NECESARIO SE MANTIENE EN LOS RESIDUOS EN EL FILTRO. DE ESTA MANERA SE OBTIENE UNA PROLONGACION DE LA POSIBLE DURACION DEL PERIODO DE FUNCIONAMIENTO. In a filtration apparatus for concentrating acidulated milk, a filter unit is located between a pump and a backpressure valve. The pump used is a displacement pump, even though the liquid to be filtered would, according to its viscosity value, permit a conventionally used centrifugal pump. During an operating period, the backpressure is gradually increased so that, in spite of increasing coverage of the filter with suspended, dissolved or emulsified constituents, the permeate flow through the filter remains constant. Owing to the characteristics of the displacement pump, the delivery rate remains the same in spite of the increasing backpressure, so that the purification effect of the delivered liquid on the deposits in the filter also remains the same. An extension of the possible duration of an operating period is achieved in this way.