IMPROVEMENTS IN AND RELATING TO FILTRATION AND APPARATUS THEREFOR Communi
Year: 1883

page_text: LETTERS PATENT to William Robert Lake, of the firm of Haseltine, Lake
"
and Co. Patent Agents Southampton Buildings London for an Invention of
"IMPROVEMENTS IN AND RELATING TO FILTRATION AND APPARATUS THEREFOR
Communicated to him from abroad by John Wesley Hyatt of Newark, New
COMPLETE SPECIFICATION filed by the said William Robert Lake at the
Office of the Commissioners of Patents on the 6th March 1883.
"
WILLIAM ROBERT LAKE, of the firm of Haseltine, Lake, and Co, Patent
Agents, Southampton Buildings, London, "IMPROVEMENTS IN AND RELATING TO
Communicated to me from abroad by
John Wesley Hyatt of Newark, New Jersey, United States of America,
Manufacturer
FILTRATION AND APPARATUS THEREFOR
This invention relates to improvements in filtration by means of filtering
agents in a granular form, and consists essentially in certain novel methods and
devices hereinafter described, and illustrated in the accompanying drawings.
Referring to Figures 1 to 5 inclusive, I will first describe the apparatus shewn
therein and then set forth the processes of filtering and the method of washing the
filter beds.
Figure 1 is a top view of an apparatus embodying the said invention
Figure 2 is a central vertical longitudinal section through two of the filters
composing the apparatus
Figure 3 is a top view of a modified form of apparatus
Figure 4 is a centrally vertical section through two of the filters composing the
apparatus illustrated in Figure 3, and
Figure 5 is a central vertical section of another modified form of the same
apparatus
In Figures 1 to 5 inclusive, each of the filters, whether used singly or in a series,
consists of a cylindrical shell or receptacle A of boiler iron, having a cast iron
head B and base C, and having at its upper portion, an inlet pipe D for the
.

page_text: unfiltered water, an outlet pipe E for the purified water, and a waste pipe F
through which the water used in cleaning the filter may issue. The apparatus
contains a bed of sand, or other suitable filtering agent, which nearly fills the
same. The inlet pipe D to the apparatus, for the unfiltered water, will be through
one pipe G or a series of such pipes, which penetrate the bed of sand and allow the
water to enter the lower part of the filter. If a series of inlet pipes are employed,
I arrange their lower ends at different heights, so that the water will be delivered
at various points through the lower half of the bed of filtering agent. On the side
of the filter opposite to the inlet pipes, is provided a section of perforated material H,
against which the sand or other agent is placed, and through which the water
issues in a purified condition to the outlet E. The perforated section H is
separated from the sides of the casing of the filter by means of lugs or pins I, and
is of a suitable nature to permit the passage through it of the water, but prevents
the escape of the sand or other filtering agent.
The operation of the filter above described is as follows:--that is to say The
water passes through the inlet pipe or pipes to the lower portion of the filter bed
or beds; a large portion of it then passes upward, through the vertical portion of
the bed adjacent to the inlet pipes, to the space in the upper portion thereof thence
downward again through the material composing the quiescent portion of the bed,
and thence through the perforated material H into the outlet; those portions of
the water which do not rise upward to the top of the bed, as indicated above, will
pass across through the filter bed to the perforated material H and then escape in
a purified condition. The effect of delivering the water at one side of the apparatus
and adjacent to the lower portion of the filtering material, is to cause the sand or
other agent in the vertical portion of the filter-bed adjacent to the inlet pipes to
be very much agitated and loosened, whereby the water will rise in large quantities
passing through the said portion of the filter-bed readily and rapidly, and thence
find its way to the other or quiescent parts of the filter-bed
During the operation of filtering, the whole body of the sand or other agent is
brought into active use, and is caused to assume such condition and consistency as
will best adapt it for the purpose for which it is intended
In washing the filter I employ the means illustrated in Figure 3. Figure 3 will
be described hereinafter and the elements shown therein for agitating and cleansing
the bed of filtering material may be applied to the single filter described above
without departing from the nature of this invention. In the said single filter, above
described, one part of my invention is illustrated; and in Figure 3 the same part
of the invention with additional improvements
In the employment of a series of the filters above-described for filtering large
quantities of water, the preferred arrangement is as follows, where for instance,
an, apparatus consisting of four filters is made use of. Each of the filters is
supplied with all the elements mentioned above as belonging to the filter first
herein before described, and, in addition thereto, will be provided with the con-
necting pipes M, which pass from the lower side of each filter (at a point by
preference directly opposite the inlet pipes) to the adjacent filter, at the upper
portion of which it enters. Each of the filters is connected with the adjacent filter
by the pipes M, so that when all the filters are connected there is communication
from one to the other, forming an unbroken circuit through the whole series. The
pipes M are supplied with the valves N, and the preferred construction is to have
them tapered slightly from their upper ends downward. The object of having the
pipes M taper from their upper ends downward, is to facilitate the passage through
them of the filtering material during the process of washing the filter beds, as
hereinafter described. The valve N is of peculiar construction and is especially
adapted for pipes through which a current of sand and water is to pass. There is
a joint in the pipes M, as indicated in dotted lines, and over this joint is slipped
a section of strong india rubber hose, the ends of which are clamped or wired in
place, and centrally upon this india-rubber section of hose is placed a clamp P having
a follower R controlled by a set screw S as shown in Figure 5'. This clamp.

page_text: composes the valve N, which is closed by pressing the follower R down upon the
hose until the two sides thereof are in contact with each other, and is opened by
the reverse of this movement
Where a series of filters are used, one of them will be left empty, that is to say
it will contain no filtering agent but only water, for convenience and to aid in the
operation of cleaning the beds; while the filters T, U, W will be supplied with the
filtering agent and with inlet and outlet pipes connected with a common supply
and delivery. It will be desirable not to stop the process of filtration entirely
during the operation of washing the beds, hence one of the filters will be cleansed
while the others are in operation
If it is desired, for instance to clean the bed of filtering agent in the filter V, the
supply of water from the inlet is continued as before, the waste pipe is opened, and
the outlet pipe closed, while the valve N in the pipe M leading to the filter W. is
opened. The effect of this adjustinent is to cause the water to drive the sand or
other agent (and pass with it), upward through the pipe M the sand and water
falling into the empty filter W whereby the sand or other agent is thoroughly
agitated and effectually cleansed. The filter V is now empty and the filter W full
of the cleansed filtering agent. The sand or other agent in the filter W may now
be employed for filtering the filter V being used to receive the sand or other agent
from the filter T, as herein-before recited. In cleaning the beds of filtering agent,
the sand or other material may be brought at will from one filter to another, one
being always left empty and idle; the sand or other agent is thoroughly agitated
and cleansed and is in condition, when delivered into the adjoining filter for use
for purposes of filtration
In Figures 3 and 4 I illustrate a modified form of construction which embodies
the principles of the filter shown in Figures 1 and 2, and differs from it, only in
the arrangement of the transfer pipe M. In this modification four filters are
employed, and the transfer pipe passes from the interior and at one side of each
filter respectively into the top of the other filter. The position of the tapered
transfer pipe M is clearly indicated in Figure 4, in which Figure it, will be observed
that the mouth of the pipe is at the lower part of the filter, while its body tapers
upward to the top of the same, and there, meeting the horizontal portion it extends
into the top of the adjoining filter. The valve for the pipe M in this modification
is placed at the top of the filter illustrated, and consists in this instance of the
disc C¹ and threaded stem D¹ which passes upward through the internally threaded
lug E', and is provided with a handle by which it may be operated. The jet
pipe X having a valve x, in this construction passes from the top of the filter and
enters the pipe M at a point about on a line with the centre of its horizontal
portion.
During the operation of washing the filter bed the force of water in the filter.
will cause a jet or small stream to flow through the pipe X into the current of sand
passing through the pipe M, which jet or small stream will facilitate the passage of
the said current and effectually prevent any clogging of the material in the pipe M;
it, also assists in loosening the impurities from the filtering agent
In Figure 5 I show a single filter provided with a receptacle to receive the bed
of sand or analogous material, instead of employing a series of filters as illustrated
in Figures 1, 2, 3 and 4. In the filter shown in Figure 5 the elements described
in Figures 1 and 2 are all employed, the difference being that the sand pipe M
instead of leading to an empty filter, leads to the receptacle a placed directly over
the apparatus The receptacle a is of sufficient size to receive the bed of filtering
agent, and is provided in its bottom with a valve b through which the sand. or
other material used as the filtering agent may pass into the filter proper at the
time desired. The upper edge of the receptacle a is provided with a waste
trough c.
In the operation of washing the filter bed, I close the outlet E and allow the
inlet D to remain open and the flow of water to continue, the valve N being
opened. The effect of this is to drive the sand through the pipe M, into the

page_text: receptacle a during which time, the flow of the water being continued, the silt and
other impurities will be loosened from the sand and will flow with the waste water
over the trough c and away by means of the spout d. After the sand has been
thus cleansed, the valve b is opened, by turning the rod and wheel, and the filtering
agent allowed to fall through the same downward into the cylinder A when it will
be in proper condition for further use. The operation of this modification of the
invention is illustrated in Figure 5 and will be fully understood from the description
of Figures 1 and 2.
Under ordinary conditions it will be found desirable to facilitate the passage of
the sand through the pipe M by a jet of water, and in such cases a pipe X having
a valve is provided. In some instances this will not be required but it will be
found, in nearly every case, advantageous, as it assists the flow of the filtering
material and the removal of the impurities.
It is well known that in filters of large area difficulty has heretofore been
experienced in cleaning the beds of filtering material, owing, in part, to the fact
that the water used for that purpose will, under usual conditions, find one or more
passages through the bed, leaving the remainder of the bed undisturbed and
uncleaned. This is true of filters containing a bed of large area, and, say, one foot
in depth, as well as in filters in which a filter bed of, say, five or eight or a greater
number of feet in depth is employed. By the forms of filter shown in Figures 6
to 10 the objection just mentioned is entirely obviated, and every part of the filter
bed may be thoroughly agitated and cleansed
Figure 6 is a sectional view of a filter employing a bed about one foot in depth;
Figure 7 is a similar view of a filter designed to contain a bed of filtering agent
of about five feet in depth; Figure 8 shows an apparatus which will be about
eight feet in diameter and which will be used for filtering large volumes of water;
Figure 9 represents a sectional view of a filter intended for household purposes, and
Figure 10 is a plan view of same
Referring to Figure 6, A indicates, what may be considered, for purposes of
description, a rectangular shaped receptacle having an inlet B, and an outlet C, and
containing, preferably, a bed of filtering material in granular or comminuted form
of about one foot in depth. The bed of filtering material, lettered D, rests upon a
sheet of perforated metal or wire cloth E or upon any other base which will permit
the passage through it of the water, without allowing the escape of the sand or
other material of which the bed may be composed. The sheet of perforated
metal E rests upon projections above the upper surface F of the hollow bottom G;
in which are formed at regular intervals the apertures H, one of the apertures
being arranged, preferably, below about every square foot of the filter bed. The
hollow bottom G is connected with a suitable supply pipo I, which leads the water
to the apparatus during the operation of washing the filter bed.
In the operation of filtering by means of the apparatus illustrated in Figure 6
the water enters through the inlet B, passes through the filter bed and escapes at
the outlet C in a purified condition. After the bed has become foul from the
deposition of silt and other impurities arrested from the water or other liquid
being filtered, the supply of the unfiltered water is cut off, and water is forced
through the pipe I into the hollow bottom G, and thence through the apertures H
and perforated metal E, into the filter bed D. The effect of allowing the water to
enter the filter bed through the apertures H, arranged in the manner described, is
to cause a thorough agitation and cleansing of every part of the filtering material.
The water which is used in cleansing the filter bed will rise over the same and
pass off through the waste trough or spout J.
If the water passing through the pipe I were allowed to flow through the
hollow bottom G and apertures H without having its force controlled, it is
probable that it would pass through the apertures H close to its outlet, and find its
way in unbroken currents through that portion of the filter bed and escape
without effecting the purposes desired. In order to secure the best results from
the influx of the water through the pipe I, I construct the apertures H of such

page_text: Bize that their area in cross section will not equal that of the pipe I, whereby there
is caused a resistance to the inflowing current which will ensure the passage of
the water through each of the apertures H. In other words I am able to secure
this result by admitting the water into the hollow bottom under a greater pressure
than the resistance offered by its passage through the inlets to the filter bed. I
have found it desirable to have a resistance of about four or five pounds to the
square inch in the hollow bottom G.
In Figure 7, illustrating an apparatus of about four feet in diameter and six
feet in height, A indicates the body of the filter which is preferably, of cylindrical
form and is provided with a hollow bottom G of similar construction to that
described in Figure 6. This filter contains a bed of filtering material of about
five feet in depth, and its inlet for unfiltered water is by a pipe K entering at one
side thereof. The inlet to the filter for the unfiltered water is provided with the
valve R, as shown, which permits the entrance of water to the filter bed but
prevents the escape of the elements composing the said bed. The valve R shown
is of a double conical form, having a cross bar S to retain it in place, but it
admits of various constructions, as will be readily understood This inlet is at the
lower part of the filter bed and at the side of the filter opposite to the outlet L.
The outlet L for the filtered water consists of a section of perforated metal or
wire cloth M connecting with the delivery pipe N and the branch delivery pipe O,
the pipe N being provided between the upper surface of the section M and its
connection with the branch pipe O, with the check valve P. The section M, is
subdivided at about its centre horizontally by a partition Q; and the branch
pipe O leads from the lower subdivision of the section M into the pipe N for the
purpose hereinafter described.
In the hollow bottom G are placed the valves A' which are similar in
construction and operation to the valve R hereinbefore described, and are
arranged at regular intervals over the bottom of the filter. The purpose of the
valves A¹ is to permit the entrance of the washing water from the hollow
bottom G into all parts of the filtering material. The valves A¹ may be used with
or without the vertical pipes R, described hereinafter, according to the character of
the filter bed. For a filter bed say, two feet in depth, the valves A¹ alone would
be sufficient to ensure a thorough washing of the filtering. medium. The vertical
pipes R arranged at regular intervals within the filter extend upward to within
about one foot and a half of the upper surface of the bed of filtering agent, and
are provided upon their sides with smaller branch pipes S having valves similar to
those described as being employed in the inlet pipe K and in the hollow bottom G.
The vertical pipes R and the smaller branches are arranged at distances from each
other which will be regulated by the size of the filter and the character of the
material used for the filter bed. The inlet to the valves A' and the pipes R with
their subdivided branches S, is by means of the supply T which leads into the
hollow bottom G. In the construction of the valves A¹ and the valves in the
branches S, I prefer to have their area a little less than that of the pipe T in cross
section, whereby there will be a resistance to the entrance of the water about four
or five pounds to the square inch, as in the case of the filter shown in Figure 6
hereinbefore described.
In lieu of arranging the inlet pipe K in the manner described, a similar result
may be secured by permitting it to enter the filter at the top of the apparatus and
having it terminate at a point in the lower part of the filter bed and at one side
thereof. The operation of the filter illustrated in Figure 7 and above described, is
as follows: that is to say. The water to be filtered enters the bed of filtering
material through the pipe K, thence it passes through the bed of filtering material
and finds its escape in a purified condition through the section M and outlet pipes
NO; the nature of the passage of the water through the filter bed will be readily
understood without a more detailed description. The water enters the section M
above and below the partition Q, that entering above the partition Q, passes
through the check valve P and away through the pipe N, while that which enters

page_text: the section M below the partition Q passes upward through the branch to the
pipe N and is thence conveyed away, the check valve P preventing the return of
the water through the pipe N into the filter. After the filter has been used a
given length of time for filtering water, the bed of filtering material, will, become
foul from the impurities arrested from the water, and will need to be agitated and
washed. To effect this, I close the inlet K and the outlet N and cause the entrance
of water into the hollow bottom G through the pipe T; from the hollow bottom G
the; water enters through all the valves A and pipes R, if both are used, or through
either if the other is omitted and passes through every part of the bed of filtering
material, thoroughly agitating and cleansing it; the water rising upward through
the bed and passing off through the escape pipe x.
Referring to Figure 8 wbich illustrates a filter for cleansing large volumes of
water, A indicates the outside wall or shell of the receptacle, G the hollow bottom
which is the same as that hereinbefore described U denotes the head of the
apparatus in which is formed an annular chamber V connecting with the delivery
pipe W. The inlet for the unfiltered water is by means of a central pipe X, leading
from a suitable supply and having a bell-shaped mouth terminating in the lower
portion of the filter bed. From the annular chamber V extends downward into
the filter bed around the outer portions thereof the series of pipes Y, which
terminate in the perforated cylinders Z, every alternate pipe Y with its cylinder Z
terminating at about the horizontal centre of the filter bed, while the other
cylinder extends into the lower portions thereof
I do not employ the pipe X and the perforated cylinder Z in all instances, as
other and simpler means may be substituted therefor with good results in some
cases. For example, in lieu of the pipe X I admit the unfiltered water in the
bottom G, as indicated by dotted lines, and lettered B¹, and dispense with the
perforated cylinders Z and pipes Y, by having an inner lining of perforated
material shown in dotted lines and lettered C', the chamber bebind which will be
connected with an outlet. It will not be necessary to employ both the pipe X
with cylinders Z, and the inlet B¹ with perforated inner lining C¹, but either may
be used with satisfactory results.
The operation of filtering water by means of the apparatus shewn in Figure 8 is,
as follows, that is to say. The water enters through the central pipe X, or through
the inlet B, according to which is used, and finds its outlet in the lower central
portions of the filter bed; its tendency will be to rise upward through the central
part of the bed. During the operation, this central part of the filter bed will
become thoroughly agitated and will attain a semi liquid consistency, while the
remaining part encircling this central agitated portion will remain in a practically
quiescent state, and the water passing through it will be thoroughly cleansed and
find its outlet through the perforated cylinders Z and the pipes Y, or through the
perforated lining C, according to which is employed, and thence through the
delivery pipe W. In order to clean the filter bed, the pipes X and W are closed,
and the water is permitted to enter the valves A', or the vertical pipes R according
to which is employed in this filter in the manner and for the same purpose as in
the filter shown in Figure 7 and hereinbefore described. The water leaving the
valves A' and pipes R passes through the bed of filtering material, rising upward
through the same and finding an outlet through the waste pipe x. In order to
prevent during the operation of the filter the return of the water from the annular
chamber V into the shorter pipes Y (when the lining C₁ is not employed) check
valves a are provided in the said shorter pipes, which will prevent the return of
the water into the bed, but will permit its escape therefrom; the liability of the
water to return to these shorter pipes, is owing to the lighter resistance in the upper
portions of the filter bed.
In Figures 9 and 10 which illustrate a filter for household purposes, the same
principles of construction and operation hereinbefore described as relating to the
larger filters are preserved. In this filter, A indicates the body of the apparatus
having a hollow base G and supply K, together with valves A'. or the pipes R,

page_text: similar to those described hereinbefore. The delivery of the filtered water, is by
means of the perforated cylinders Z and their connecting pipes Y, which in this
filter are arranged at one side thereof and opposite to the inlet. At the upper part
of the filter there is a waste pipe x through which the water employed for cleansing
the filter bed escapes. The inlet to the filter for the unfiltered water and for the
water used in cleaning the filter bed is one common supply pipe b provided with
two branches c, d, one leading to the supply for the unfiltered water and the other
to the hollow base, a three way cock being provided at the point of junction of
the branch pipes c d, with the main pipe b, whereby the current of water may
be directed either into the branch c or d according as, it is desired to filter the
water or wash the filter bed; the water to be filtered enters through the inlet K
and escapes through the cylinders Z and pipes Y. In cleansing the filter bed the
inlet K and the delivery pipe connecting with the pipes Y and cylinder Z are
closed, and the water is caused to flow through the branch c into the hollow
bottom G, thence through the valves A' or the pipes R, according to which is used,
whence it will rise through the filter bed and escape through the waste pipe x.
Having thus fully described the said invention as communicated to me by my
foreign Correspondent, and the manner of performing the same, I wish it
understood that I. Claim.
First. In cleansing granular filter beds, the method of removing the impurities
therefrom by transferring the filtering material under water pressure from one
compartment to another in such a manner that the particles of which the bed is
composed are brought into frictional contact with one another and with the water,
and are thereby purified, which method consists in inducing a current of the
filtering material together with a stream of water, from one compartment or
receptacle to another and conducting the separated impurities away with the
waste water.
Second. The filter herein described consisting of a receptacle containing a bed
of filtering material, an inlet arranged to deliver the water at one side and in the
lower parts of the said bed, the outlet E, and the perforated section H arranged on
the side of the filter opposite to the inlet, in the manner described and for the
purposes specified
Third. The filter herein described containing a bed of filtering material and
provided with an inlet for unfiltered water, the tapered pipe M having a valve,
and being connected with a suitable receptacle for receiving the bed of filtering
material during the process of washing the same, the transfer of the bed from the
filter to the said receptacle being induced through the pipe M substantially as and
for the purpose set forth.
Fourth. The filtering apparatus herein described, consisting of a series of filters,
each supplied with independent inlet and outlet pipes, and connected with each
other, so as to form an unbroken circuit, by means of the pipes M provided with
valves, which pipes pass from the lower portion of one filter to the upper portion
of the adjacent filter and are adapted to permit the transfer through them of
the bed of filtering material when it is desired to cleanse the same, substantially
as specified.
Fifth. In a filtering apparatus consisting of two or more receptacles, having a
proper supply and delivery, the transfer pipe M and jet pipe X as, and for the
purpose, set forth.
Sixth. The filter herein described, consisting of a receptacle having an inlet and
an outlet and containing a bed of filtering material, and provided with a series of
openings at its lower portion for the entrance of the water to be used in washing
the bed, combined with a series of automatically operating check-valves which
control the said series of openings, the said openings being arranged as set forth,
and having a combined area in cross section less than the area of the pipe
supplying them, substantially as described.
Seventh. The filter herein described, consisting of a receptacle containing a bed
of filtering material an inlet at the bottom of the said bed for unfiltered water,
•

page_text: and an outlet for the purified water adjacent to the sides of the receptacle, the
construction being such, that during the operation of the filter the vertical portion
of the filter bed above the inlet will be agitated or put in a state of ebullition, and
the surrounding portions will remain in a quiescent condition, substantially as set
forth.
:
:
Eighth. The filter herein described, consisting of a receptacle containing a bed
of filtering material and having a hollow bottom G, and a series of inlets each
provided with a check-valve A, which valves permit the entrance of the water
used in washing the filter bed and prevent the escape of the elements thereof,
substantially as set forth.
Ninth. In a filter, a hollow bottom having an inlet and the vertical pipes having
branches substantially as set forth
Tenth. A filter consisting of a receptacle having an inlet for the unfiltered water
by the central pipe X, and outlets for the clean water by the pipes Y and perforated
cylinder Z, the said outlet pipes being adjacent to the outer portions of the filter
bed, substantially as set forth.
In Witness whereof I the said William Robert Lake, have hereunto set my hand
and seal this Sixth day of March in the year of our Lord One thousand eight
hundred and eighty three.
.
TTH DADE T