Improvements in Filters.
Year: 1894

page_text: Date of Application, 14th July, 1894
Complete Specification Left, 16th Apr., 1895-Accepted, 18th May, 1895
PROVISIONAL SPECIFICATION.
Improvements in Filters.
I; ALEXANDER TURNBULL, of the Firm of A. Turnbull & Co. Engineers,
Bishopbriggs in the County of Lanark, do hereby declare the nature of this
invention to be as follows:-
This invention which relates to filters for use chiefly in freeing the feed water
for steam boilers from oil or greasy matter and other impurities has for its object
to provide for renewing or replacing the filter cloth or other filtering medium
employed without the necessity of opening up the filter for that purpose.
To that end the filter cloth instead of being permanently or temporarily secured
on the surface of the perforated plate or drum or other support through which
the feed water or other liquid passes, is carried in a roll or rolls within the filter,
80 much of it as is required to cover the perforated support being rolled or drawn
over said support, and when that portion of the length of the filter cloth has
become clogged or saturated with impurities it is drawn off by suitable means from
the outside of the filter, a fresh length being thereby drawn from the roll on to
the support.
In filters of cylindrical or drum formation to which the invention is especially
applicable, the roll of filter cloth is or may be carried upon a roller parallel with
the axis of the perforated cylinder or drum and within the filter casing, the filter
cloth being carried from the roll around the outer periphery of the cylinder, or
through a slit or slits in the cylinder and around its inner periphery, and thence
passing round a beam or roller whose end is carried through the filter casing and
provided with a hand wheel or like means for turning the beam to wind on it the
filter cloth as it becomes clogged, this condition of the filter cloth being readily
ascertained by the increased pressure required to force the liquid through the
cloth..
The perforated cylinder or drum is in one modification carried upon a spindle so
as to be rotated by the filter cloth wound over it, and when the filter cloth is
carried around upon the inner periphery of the drum, an inner rotating perforated
drum is provided to facilitate the winding operation. The roll of filter cloth is by
preference placed within a compartment of the filter casing separated by a web or
partition from that in which the drum is situated in order to isolate the fresh filter
cloth as far as practicable from the impure water, the cloth being led through a
slit in the partition and between a guide roller or rollers and the drum and the
uncovered part of the drum being placed. in close proximity to the web or
partition.
The spindle carrying the perforated drum may be carried through the filter
casing and provided with a pointer or indicator to show by its revolutions the
quantity of filter cloth drawn over it.
In filters composed of flat or curved perforated plates or like supports the filter
cloth. may be simply carried across the facer of the plate and drawn from the roll at
one side on to a beam at. the opposite side.
Dated. this 13th day of July 1894
CRUIKSHANK & FAIRWEATHER,,
62, St. Vincent Street,, Glasgow, Agents.

page_text: Improvements in Filters.
I, ALEXANDER TURNBULL, of the Firm of A. Turnbull & Co., Engineers,.
Bishopbriggs, in the County of Lanark, 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 :-
This invention which relates to filters for use chiefly in freeing the feed water
for steam boilers from oil or greasy matter and other impurities has for its object
to provide for renewing or replacing the filter cloth or other filtering medium
employed without the necessity of opening up the filter for that purpose.
To that end the filter cloth instead of being permanently or temporarily secured
on the surface of the perforated plate or drum or other support through which
the feed water or other liquid passes, is carried in a roll or rolls within the filter,
so much of it as is required to cover the perforated support being rolled or drawn
over said support, and when that portion of the length of the filter cloth has
become clogged or saturated with impurities it is drawn off by suitable means from
the outside of the filter, a fresh length being thereby drawn from the roll on to
the support.
The invention is illustrated by the accompanying drawings, Figure 1 being a
vertical section, on the line x-x, Figure 2, Figure 2 a cross section on the line y-y
Figure 1, and Figure 3 a plan of the improved filter.
In filters of cylindrical or drum formation as represented in the drawings, to
which the invention is especially applicable, the roll of filter cloth A is or may be
carried upon a roller B parallel with the axis of the perforated cylinder or drum C
and within the filter casing D, the filter cloth A being carried from the roll B
around a guide roller E and around the outer periphery of the cylinder C, or
through a slit or slits in the cylinder and around its inner periphery, and thence
passing round beams or rollers F, G, the latter having its end carried through the
cover H of the filter casing D and being provided with a hand wheel I or like
means for turning the beam or roller G to wind on it the filter cloth A as it
becomes clogged, this condition of the filter cloth A being readily ascertained by
the increased pressure required to force the liquid through the cloth.
The perforated cylinder or drum C is carried upon a spindle c so as to be rotated
by the filter cloth A wound over it, and when the filter cloth A is carried around
upon the inner periphery of the drum, an inner rotating perforated drum is provided
to facilitate the winding operation. The roll B of filter cloth A may be placed
within a compartment of the filter casing D separated by a web or partition from
that in which the drum C is situated in order to isolate the fresh filter cloth A as
far as practicable from the impure water; the cloth A being led through a slit in
the partition and between a guide roller or rollers and the drum C and the
uncovered part of the drum C being placed in close proximity to the web or
partition. Or as shown the roll B may be enclosed within a cylindrical casing J
provided with a slit through which the cloth is led between the beam or roller E
and the drum, snid drum bearing on an extension of the casing J and the
roller E being placed as close as possible to the slit jin order to prevent the passage
of the water through the filter cloth in a direction other than through the drum C.
According to the arrangement shown an inlet valve K is provided through which
the water passes to the interior of the filter casing D thence through the filter
cloth and the perforated drum C downward through the hollow spindle of said
drum and out through an outlet valve L as shown by the arrows, Figure 1.
The spindle carrying the perforated drum C may be carried through the
cover H of the filter casing D said spindle being geared to a train of wheels h, h¹,
h³, h, on the spindle of one of which is a poiuter or indicator A to show by its

page_text: position on a dial * provided on the casing D the number of turns or part thereof
of the drum C and consequently the quantity of filter cloth A drawn over it.
When it is desired to remove the filtering apparatus or when the filter is not in
use the inlet and outlet stop valves K, L, provided on the filter are closed and a
bye-pass M opened to allow free passage of the water.
In filters composed of flat or curved perforated plates or like supports the filter
cloth may be simply carried across the face of the plate and drawn from the roll
at one side on to the beam at the opposite side.
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 :-
1. A filter the parts of which are constructed and arranged to operate sub-
stantially as described.
2. A filter arranged to carry a continuous web or roll of filter cloth and having
means for replacing the clogged or saturated filter cloth by a fresh portion from
the roll without removing the cover of the casing, substantially as described.
Dated this 13th day of April 1895.
CRUIKSHANK & FAIRWEATHER,
62, St. Vincent Street, Glasgow, Agents.