Improvements in and relating to Filters.
Year: 1895

page_text: Date of Application, 13th Aug., 1895-Accepted, 14th Sept., 1895
COMPLETE SPECIFICATION.
Improvements in and relating to Filters.
I, JOHN MILTON DAVIDSON, of 95 Arch Street, in the City of Allegheny,
County of Allegheny and State of Pennsylvania, in the United States of America,
Manufacturer, do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained by the
following statement :-
My present invention relates to filters and has especial reference to that class of
filters which use a tubular porous filtering body, such as stone or composition
through which the water is required to pass.
In this class of filters the periphery
of the filtering body becomes rapidly coated with the impurities of the water and
these impurities must be forcibly removed; to accomplish which, scrapers, brushes,
pebbles held stationary in compartments, etc. have been used, but owing to the
softness of the filtering body these cleaning devices wear the filtering body away
very rapidly and require the removal of the cleaning devices for readjustment
with reference to the filtering body in order to keep them effective.
wearing away of the filtering body and the cleaning device after a time results in
defective cleaning until the filter becomes inoperative, when the cleaner must be
adjusted.
This
It is my purpose to keep the filter up to its maximum filtering capacity from the
time it is put into use until the filtering body is worn out, by providing a granular
bed which surrounds the filtering body and serves first to arrest the coarse and
major portion of the impurities when filtering and then to scour the inner
surface of the filter casing and outer surface of the filtering body while the
granular bed is being cleansed by attrition of its particles and thus avoid
the necessity of removing the cover of the filter except to renew the filtering
material.
With this object in view the invention will be fully disclosed in the following
Specification and claims.
In the accompanying drawings which form part of this Specification
Figure 1 represents a vertical section of my improved filter.
Figure 2 a top plan view on the line Figure
Figure 3 a transverse section on the line y y.
and
Reference being had to the drawings and the letters thereon, A indicates the
casing of the filter, B the base and C the cover. Within the casing and concentric
therewith is a tubular filtering body D, of porous stone or composition such as is
commonly used for the purpose, and said body is supported upon a hollow journal a
which engages a bearing on the base B. The journal is provided with a
concentric flange c and with an extension d which enters the filtered water
chamber e of the filtering body D, and in the wall of the extension are openings f
for the passage of filtered water to the discharge pipe E. The journal a is secured
to the body D by a rod h which engages the extension d and the disk h¹ at the
upper end of said body, and the body is securely clamped between the flange cand
the disk so that they will revolve together on the journal a; and between the
ends of the body D and the flange cand the disk h¹ are packing gaskets ik to
prevent unfiltered water entering the chamber e.
From the disk extends an arm through the cover C and its stuffing
box m which is provided with a crank n to revolve the body D when it is
desired to cleanse the body of the impurities which accumulate on its surface.

page_text: F indicates a vertical bar attached to one of the rods o which secure the
base and the cover to the body of the filter and is set at an angle to the periphery
of the filtering body D to form a funnel shaped passage p to direct the granules
against the body when the filter bed is being cleansed.
In the base B, is a concentric water supply chamber q provided with a pipe G and
a foraminous upper side through which water issues in numerous fine streams, and
an over-flow or waste pipe H is attached to the base on the side opposite the supply
pipe G and extends up through the filter to the upper end and the mouth of the
pipe is covered with a fine wire screen s to prevent waste of the granular bedt when
it is being cleansed.
The several pipes E, G, and H are supplied with stop-cocks (not shown) to
regulate the supply and discharge of water.
In the operation of filtering water, the water enters the chamber through pipe G
and is distributed through the holes in the upper side of the chamber so as to pass
evenly up through the granular bed where the water is relieved of the coarse and
major portion of its impurities and then passes through the wall of the filter body D
into the chamber e from which it passes through the openings f in the extension d
into the discharge pipe E.
To cleanse the filter the pipe E is closed and the pipes G and H opened when
the water loosens and raises the granular bed and as the filter body D is revolved
the granules acquire a circular motion imparted by the revolving body and as they
pass between the bar F and the surface of the body they scour and remove the
accumulated slime and other impurities from said body. At the same time the
granules as they are dashed about cleanse themselves by attrition of adhering
impurities and also scour the inner surface of the body A of the filter and
cleanse it, while the impurities rise to the upper end of the filter and flow
through the waste pipe H, thus avoiding the necessity of removing the cover of
the filter and cleansing the inner surface of the body A of the filter by hand.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
First. A filter provided with a revoluble tubular filtering body and a granular
bed surrounding said body in combination with an inclined deflector for directing
free granular material against the periphery of the body.
Second. A filter provided with a revoluble tubular filtering body and a free
granular bed surrounding said body, an inclined deflector and means for raising
said bed and scouring the walls of the filter and filtering material.
Third. A filter provided with a base having a concentric water chamber provided
with perforations in its upper side and a hollow journal bearing, in combination with
a revoluble filtering body supported on said bearing and a spring between the cover
of the filter and the filtering body.
Fourth. A filter provided with a revoluble filtering body, a granular bed
surrounding said body, and a bar set at an angle to the periphery of the body,
in combination with a water supply below the granular bed and a waste pipe above
said bed.
Dated this 13th day of August 1895.
JENSEN & SON,
77 Chancery Lane, London, W.C., Patent Agents.