backwash


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backwash

The reversal of the direction of a usual pattern of flow.
References in periodicals archive ?
In this context, this study aimed to evaluate the methodology of sampling of sand from contaminated filter beds in pressurized sand filters used in irrigation, with possibility of application in the evaluation of performance in backwash processes.
coli in over half of filter backwash samples indicates that swimmers frequently introduced fecal material into pools and thus might transmit infectious pathogens to others.
However, until recently, few or not data existed on the efficacy of constructed wetland systems to treat backwash water; even though, one of the most common methods to treat backwash water has been settling in lagoon facilities (Montgomery, 1985).
Activated carbon unit backwash should be performed at a face velocity of about 1 1/2 times the operating face velocity.
The recommended relay point is 75% of the initial flow rate and the backwash is achieved by a collection of automatic valves opening and shutting to reverse the flow direction.
It is an outlet pipe of some sort and when he fell forward he created a backwash and was completely sucked in.
Englewood, NJ, offered a complete system approach where the filters, manifolds and all necessary valves, hardware and gaskets were pre-assembled and prewired, requiring only inlet, outlet, backwash and power-supply connections.
The unique circular configuration features an indexing flow diverter that rotates from station to station, as required, to take a single station off-line for backwash cleaning.
As codified in 1979 by Dick Hebdige in his short book Subculture: The Meaning of Style (and beautifully timed to ride the backwash of punk), Cohen's idea of the Subcultural Imaginary was transformed into a how-to manual for those who wished to export and duplicate the success of Britain's pop machine.
The crashing surf and backwash (backwards pull) from waves also make her job anything but a "day at the beach.