Richmond dispatch. [volume] (Richmond, Va.) 1884-1903, 1897-04-01
Improved Method of FILTRATION.
0Ralfimnre SunD

Cons,Il-General Mason reports to the
state BeIurtment the operation at
Worms. Kiel. and other towns, OF a ne"
system OF water filtration. when -
thought to have certain advantages over
the method OF fltering through sahd OF
gravel River water may be pre'ly
effactuaKy purified by filtration throusn
a layer OF sand, thirty or forty lhcne9
thick, but the sand. after time, De
comes choked with filth, and has 10 De
renewed \ large area has 10 be en-
ploved. moreover. as there must pe
second hltering area brought INTO use
while the first is undergoing renewal
In proportion TO the amount OF water
TO be treated. the acreage IS eNcesslNe
and expensive. What IS wanted Is an
apparatus occupying less space ana more
economical ~,
This is supplied. 81 is thought. by III
ter invented by Herr Fischer, water
works engineer of the city Of Worms.
where the filthy Rhine water has to be
used for culinary and drinking purposes.
His device consists, essentially, OF a
hollow, porous plate, made OF sharp
clean sand baked with puyeriZed glass
at a high temperature. The heat forms
a coherent mass. which will take any
desired form, and is yet sufficiently
porous to let water. under a slight pres
sure, pass through with sufficient rapid
ity Water passed through a pate OF
yitrifed sand three inches thick Is
cleaned almost as thoroughly, IL Is founn.
as by traversing three feet OF loose sand
I'm the ordinary sand-fltering process.
In constructing the altering plant.
SAYS Consul-General Mason, these plates
are set upright in groups or batteries Of
fnr "A
size and capacity of the establishment,
and are ranged along the lower portion
Of one or more tanks OF hydraulic ma
sonry, where they can be covered to a
depth OF or feet with the water TO be
filtered The water is then forced by
it's own pressure through the porous
walls of the plate into the interior hollow
space. where II trickles down. and is
drawn off through pipes laid at the bot
tom OF the tank to the reservoir which
receives the filtered water. These dis
charge pipes are rugged with cocks, so
that each plate and group of plates
may be isolated for cleaning or other
purposes while the adjacent batteries
are I'm operation. For greater economy
Of space and tubing. two tiers OF plates
are set. one above the other. The plates
being set upright and close to each
Otnfl. increase lltU1 eight ~ A'hiDiA N'4N
fltering surface that may be condensed
within any given superficial area, thus
securing an important economy Of space
within frost-proof constructions. and
where. as is often the case, land is costly
and difficult to obtain" In order 10
clean the filters II is necessary only 20
reverse the direction Of the water
through the plates, with a slight increase
OF pressure.
The Fischer plant has been in use at
Worms for four years. without accident
or appreciable deterioration. plant Of
800 plates. set up and ready for operation.
costs about $500. and occupies some
80 square yards as against sand-hlters
Of equal efficiency. costing $1,000. and
occupying some 40 square yards. \
Fischer plant does about ten times the
work done by a sand-plant Of the same
area. 1t appears. as a result OF care
ful analysis by competent persons that
the efficiency of the two systems, when
worked side by side. is about the same
as regards the effect upon the purity Of
the water If there is a difference. IL
is I'm favor Of the "sand-flter when
Clean" the percentage Of bacteria ira
versing the sand being slightly less.