Improvements in Filters.
Year: 1891

page_text: Date of Application, 2nd June, 1891-Accented, 22nd Aug., 1891
Improvements in Filters.
A communication from abroad by JUNIUS ALBERT BOWDEN, 104, Joy Street,
of Detroit, in the County of Wayne, and State of Michigan, United States of
America.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for Foreign
Patent Solicitors, 6, Lord Street, Liverpool, and 6, Bank Street, Manchester, both
in the County of Lancaster, and 323, High Holborn, in the County of Middlesex,
Civil Engineer, do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement:-
on
This invention has for its object certain improvements in filters whereby the
same are arranged to prevent the weight of the filter-bed from coming directly
to the outlet strainer; also, in means whereby a more thorough cleansing of the
filter-bed may be accomplished; also in means for simplifying the general
operation of the filter, whereby it is better adapted to be cared for by unskilled
persons.
In the drawings:-
Figure 1 is a single chamber filter with an inverted conical bottom and a strainer
surrounded by an outlet chamber.
Figure 2 is a detail view of the valve shown at the top in Figure 3.
Figure 3 is a similar filter with a right conical bottom and perforated nozzle
beneath.
Figure 4 is a view of a variation in which there are depending pipes provided
with wash nozzles at their lower ends..
In carrying out the invention —
A, is the case; B, the filter-bed; C, the water inlet conduit; D is the filtered
water outlet; E is the wash water outlet leading to a drain: F is a valve
governing the admission of water for filtering or for washing, and governing also
the outflow of filtered water or wash water; H represents depending wash water
conduits provided at their lower ends with perforated nozzles H₁; J is a valve
actuated by an exterior handle J, whereby incoming wash water may be directed
either down through the central pipe, or through the surface wash, or down
through the depending pipes H. K is a strainer through which filtered water is
discharged. L is a shield for supporting the superincumbent filter-bed and
preventing it from bearing directly upon the perforated strainer K. This strainer
may, as shown in Figure 1, be located at the bottom of an inverted conical base A.',
in which event it is preferable to surround it with an outlet chamber k, and to fill
the immediate interior of the nozzle with coarse granular filtering material k', or,
as shown on Figure 3, the shield L may itself constitute a right conical bottom
beneath which the strainer K may be located. In this construction, the strainer
will be empty, and the coarse granular filtering material be located around the
same beneath the shield.
The valve F is provided outside the filter case with orifices for the conduits C, D
and E. Its plug has a channel adapted, when in filtering position, to admit
water through C and discharge the same into the filter above the filter-bed, while
the central orifice in the plug will permit water to pass up through the pipe D',
thence through the orifice f and off through the outlet D. The valve case has
another orifice f², which, during this operation, remains closed. When the valve
is in the position shown in Figure 2, the inflowing water passes down through the
pipe D'.
It rises through and washes the filter-bed, and the wash water escapes
through the passage and out to the drain conduit E, while the filtered water

page_text: outlet remains closed. A quarter turn closes off both the inflow and the outflow of
water.
M represents a disc, which may contain suitable indications, and m is an index
finger on the valve handle. Thus, the disc may have at the proper points the
words 'filter, wash and 'close,' so that, if the index finger is brought over the
word filter, the valve is in position to admit water and filter the same; if the index
finger is over the word wash,' the valve is in position to pass water through the
filter in a reverse direction, thereby closing the filter-bed; and, if the index finger
is over the word 'close,' both the inlet and outlet passages are closed off.
G is an alum tank such as is commonly used in connection with filters connected
by a shunt pipe G with the inlet conduit C. N, N1, N2, etceteri, represent cut-off.
valves arranged in the main pipe and the shunt pipe, to regulate the flow of water
into the tank; N' and N2 being in the shunt pipe and so arranged that when open
a portion of the water passing into the filter, will pass through the alum tank and
take up and carry into the filter a portion of the alum; inasmuch as only a very
small portion of alum is desired in the filtering tank, the valves N1 N2 are
generally kept closed except during the time that the filter bed is being washed;
if the valves N1 N2 are left open during this period, sufficient alum will have
passed in to produce the desired deposit, during the time intervening before the
filter-bed ought to be again cleansed.
The operation is as follows:-
Water entering the filter through the inlet conduit passes thence through the
passage of the valve F, and discharges into the filter case above the filter-bed.
It passes thence down through the filter-bed, and, having been thus filtered, it
passes through the slits or perforations of the strainer K; thence up the conduit D',
and out through the filtered water outlet D. Now, when it is desired to wash the
filter-bed, the valve F is turned through 90 degrees. When the valve is in this
position, the water entering through C passes thence into the interior of the valve
plug and down through the pipe D, thence through the slits or perforations of
the strainer K, and up through the filter-bed, thoroughly cleansing the same.
The wash water then escapes by passing up through the valve passage, and out
through the drain conduit E.
Again, if it be desired to close off the filter, it can be done by a further rotation
of the valve F, which closes both the inlet and outlet orifices. For a plain filter,
the construction shown in Figure 1 or Figure 3 will suffice; but, in a larger filter,
or where it is desirable to cleanse the filter more quickly and effectually, depending
pipes H, leading from the pipe D¹, are provided, and they are also preferably
provided with perforated nozzles or strainers H' at their lower ends near the base
of the filter-bed. The flow of water down through these pipes is governed by a
valve J having an exterior handle J. This is simply a two-way valve, adapted,
when in one position, to leave a free opening down through the pipe D', in which
position it cuts off all communication with the depending pipes H. The valve
may, however, be turned so as to cut off the flow downward through the pipe D',
and direct this flow out from the pipe D' and downward through the pipes H.
Thus, the operator is enabled to cleanse the filter, in the way above explained,
during any desired period of time. He may then, by turning the valve, cut off
the flow through the strainer K, and cause the wash water to be discharged into
the filter-bed through the nozzles or strainers H. This thoroughly agitates the
intermediate sections of the filter bed, and greatly facilitates the cleansing of the
same.
The bottom of the filter case may have an inverted conical bottom A', as shown
in Figure 1, in which case the strainer K is located at its bottom or apex. This
serves to direct the down flow of water uniformly through all parts of the filter-
bed towards this strainer, and prevents the tendency that would otherwise exist
of the water flowing along certain courses of least resistance, while the flow through
other portions is retarded and permitted to become more or less stagnant. This
construction also greatly facilitates the washing of the filter-bed. The wash water

page_text: is concentrated at the nozzle at the base of the inverted cone, and issues in a strong
jet. This produces a strong current up through the immediate portion of the
filter bed, and the inclined bottom directs the adjacent portions of the bed constantly
toward the jet of water as the bed settles by gravity. This constant shifting of
the bed breaks up the tendency of the water to rise through a single course or
channel, and causes it momentarily to shift from one course to another, according
as any particular part of the bed may, at any moment, afford a path of least
resistance. This results in thoroughly cleansing the entire bed.
Instead of the inverted conical base shown in Figure 1, there may be a right
conical base in the form of a shield, as shown in Figure 3. In this latter construc-
tion, the operation of the filter is the same; but, when washing the filter bed, the
wash water emerging from the strainer K is directed outwardly and emerges from
beneath the edges of the cone. The flow of water is not nearly so strong as in the
device shown in Figure 1, but it rises through the portions of the filter-bed adjacent
to the sides of the case, and the filtering material, as it settles, slides down the
upper surface of the cone and is directed thereby to the edge of the cone, and
brought under the influence of the washing current until the entire bed has been
cleansed and this action may be materially hastened by directing the water
downward through the depending pipes H at frequent intervals.
It will be observed that, in Figure 1, the strainer K is filled with coarse
granular filtering material k¹, and is surrounded by a discharge chamber k. The
coarse material protects in a great measure the fine orifices of the strainer, and
prevents accumulations of fine material, which might otherwise impede the action
of the filter.
Again, the surrounding chamber greatly facilitates the free backflow of washing
water when cleansing the filter bed, permitting it to enter simultaneously from all
sides, and creating a strong flow through the coarse granular material within the
strainer, thus quickly and effectively cleansing it.
In the construction shown in Figure 3, the coarse granular material is. located
outside, but immediately surrounding the strainer K. A similar action of the wash
water takes place, but in a less degree. It has been found of great importance to
shield the strainer K from the direct weight of the superincumbent filter-bed.
This is accomplished by a right conical shield L, in Figure 3, and is in like manner
accomplished by the flat shield L in Figure 1. In the perspective shown in
Figure 4, represents a faucet from which filtered water may be drawn for use or
for testing, and P₁ is a drain cup connected with the drain pipe E. E' may be
any suitable trap.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, as communicated to
me by my foreign correspondent, I declare that what I claim is :-
1. In a filter, the combination, with the water inlet pipe, of a filtered water
discharge pipe having its entrance end located at the base.of.the.filter, and provided
at said entrance end with a strainer, and a shield located above the strainer for
supporting the superincumbent filter-bed and preventing it from bearing directly on
the strainer, substantially as described.
2. In a filter, the combination, with a water inlet conduit and a filtered water
outlet conduit with its entrance end at the base of the filter, of a strainer at the
said entrance end, and a conical surface upon which the superincumbent filter-bed
rests, the construction being such that, as wash water is reversed through the
filtered water outlet to wash the filter-bed, said filtering material will constantly
shift by gravity down said conical surface into the current of wash water,
substantially as described.
3. In a filter, the combination, with the filtered water outlet at its base, of a
perforated strainer at the inner end of said conduit, granular filtering material
immediately adjacent to said strainer between it and the filter-bed, and a shield at

page_text: the immediate base of the superincumbent filter-bed between said filter-bed and
said granular filtering material, substantially as described.
4. In a filter, the combination, with a filtered water discharge conduit leading
from the base of the filter and provided with a strainer, of a series of depending
pipes extending down through the filter-bed, and provided with strainers or perforated
nozzles at their lower ends, and a valve or valves adapted to direct a current of
wash water back through the filtered water outlet, or down through the depending
pipes, at the will of the operator, substantially as described.
5. In a filter, the combination, with an upright filtered water discharge pipe
entering at the top of the case and extending down to the base of the filter,
provided at its lower end with a perforated strainer, of a shield above the same for
supporting the superincumbent filter-bed, and provided at the top of the pipe with
a valve adapted outside of the case to receive the water inlet, filtered water outlet,
and wash water outlet conduits; said valve adapted, when in one position, to admit
feed water through it into the top of the filter case above the filter-bed, and to.
lead filtered water up through the upright pipe and out through the valve; and,
when in another position, adapted to admit wash water down through the upright
pipes, thence up through the filter bed and out through the valve to the wash
water outlet, substantially as described.
6. The valve F, constructed substantially as described, and provided with an
indicating disc and index finger, substantially as shown and set forth.
7. In a filter, the combination, with an upright filtered water discharge pipe
entering at the top of the case and extending down to the base of the filter,
provided, at its lower end, with a perforated strainer, of a valve at the top of the
pipe adapted, outside of the case, to receive the water inlet, filtered water outlet
and wash water outlet conduits; said valve adapted, when in one position, to admit
feed water through it into the top of the filter case above the filter bed, and to
lead filtered water up through the upright pipe and out through the valve, and,
when in another position, adapted to admit wash water down through the upright
pipes, thence up through the filter bed and out through the valve to the wash water
outlet, substantially as described.
.8. The combination, with a filter, of a filtered water outlet pipe adapted to serve
also as a wash water inlet pipe, provided with a strainer at the inner end, and a
chamber surrounding said strainer, into which the wash water passes before entering
the strainer, substantially as described.
9. The combination, with a filter, of a wash water inlet adapted to serve also as
a filtered water outlet, a strainer at its inner end and a right conical shield between
the filter bed and the strainer, substantially as described.
Dated this 30th day of May 1891.
WM. P. THOMPSON & Co.,
Agents for the Applicant.