Up′ward Fil′ter.
A filter which the flow of the liquid is upward, giving a certain degree of facility for cleansing the material, by directing a current of clean water in the reverse direction, and giving a downward discharge.
In
White and Aveline's artificial spring or upward filter (
English), the water is taken from a cistern and admitted by a pipe
b into the lower chamber
c of the filter.
It then passes through the porous stone
f into the upper chamber, whence it is drawn as required.
A float on the surface of the water acts upon a faucet
o to allow the flow of water as the supply of filtered water fails.
 |
|
White and Aveline's upward filter. |
When the water in lower chamber
c becomes muddy, the faucet
g is opened and the contents discharged, thus flushing the chamber and washing off the bottom of the stone.
See also filter.
In
Turkey, a method of filtering water by ascension has been practiced, the arrangements for which are contrived as follows:--
Two wells are dug at a small distance apart, and partially filled with sand and gravel.
The opening of that into which the water to be filtered is to run must be somewhat higher than that of the one into which it ascends; this latter should not be quite filled with the filtering material so that there may be room for the filtered water, or the water may be conducted by a spout into a reservoir.
Two casks, tubs or other vessels may be used.
By this method the particles of sand or other filtering material used do not rise and mingle with the filtered water in the receiving-vessel.
