Certain Improvements in Filters.
Year: 1890

page_text: COMPLETE SPECIFICATION.
Certain Improvements in Filters.
I, EDWARD MARTIN KNIGHT, a citizen of Great Britain, residing at San Mateo, in
the county of San Mateo, and State of California, one of the United States of America,
Gentleman, 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 :-
My invention relates to that class of filters in which a fibrous or porous material is
employed as the filtering medium. It has for its object the prevention of leakage
of the unfiltered liquid into the filtered liquid to render the percolation of the liquid
through the filter free and uniform, to simplify and expedite the process of filtration,
cleansing of the filter, and renewing of the filtering medium.
My invention comprises an improved mechanism for extending and holding in
position the fibrous filtering material with the filtering or purifying medium sustained
upon its surface, and for the purpose of securing a uniform flow of the liquid through
the filter.
Referring to the accompanying drawings for a more complete explanation of my
invention.
Figure 1 is a view showing the side of one of the filters and a part of the enclosing
case broken away.
Figure 2 is a transverse section taken vertically through the filter and its enclosing
case.
Figure 3 parts of filter shown detached.
To construct my filter I take a frame A, which may have any desired number of
transverse bars extending across it to act as a support for the filtering surfaces B,
which are placed upon opposite sides of this frame. The frame is of sufficient
thickness to insure a considerable space between the surfaces B, B, into which the
water or liquid to be filtered will flow through the filtering surfaces.
The frame may also have such superficial area as is desired.
The filtering surfaces consist of asbestus or other fibrous cloth, which is stretched
over each side of the frame A, and is then secured in place by means of frames (),
in the form of open parallelograms, which are laid upon the opposite edges of the
frame A, and the fibrous filtering sheets B, which extend over these edges, and are
then secured firmly together by bolts D, passing through the frames A, and C, and
held by nuts.
Upon the surface of the asbestus or other fibrous cloth, I place a layer of filtering
medium, which may be applied in the form of a paste, and which will retain its
place by reason of being brushed into the fibers of the cloth, and also because it is
kept perpetually moist when in use.
Sometimes I find it advisable to place over each side a netting E, of wire to help
sustain the filtering medium, which, owing to the frame being in a perpendicular
position, would be liable to fall when of any considerable thickness.
This method allows of a much thicker layer of filtering medium to be used than
otherwise would be.
This makes the chamber between the opposite sides of the filtering material
into which the water flows as it passes through the filter, and, by reason of the
manner in which the edges are bolted together, no liquid can reach the interior of this
chamber without first passing through the filter.
In order to aerate the water, after it has passed through the filter, a pipe F, is
fitted into the upper edge of the frame A; this pipe opening into the space between
the filtering sides and extending up high enough to prevent any water from flowing
into it from above. The water is discharged by means of a similar pipe or cock
connected with the lower side of this space, preferably through the frame A,

page_text: The filtering frames A, with their fibrous filtering sides B, are easily removed
from the tanks or chambers in which they are placed when at work, and from the
enclosing case G, for the purpose of cleansing if they become covered with deposits,
and the filtering medium coating may be renewed at pleasure. I prefer to make these
frames of iron and to employ asbestus cloth as the fibrous filtering material.
This enables me to easily cleanse the filter by plunging it into the fire, if this course
be found desirable, as no portion of the filter can be destroyed by this action, and the
surfaces will be entirely cleansed of any undesirable deposit.
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 :-
A filter consisting of a frame having asbestus or other fibrous material stretched
over its sides, clamping-plates and bolts whereby the cloth is held in place, and an
exterior cover of wire screen.
T
1
1
1000
Datou
NOT STITO
Fourteenth day of Jan
anuary 1000.
For the Applicant,
W. E. GEDGE,
Agent.