Improvements in and relating to Feed Water Filters.
Year: 1899

page_text: Date of Application, 16th June, 1899
.
PROVISIONAL SPECIFICATION.
Improvements in and relating to Feed Water Filters.
We, ISAAC SHIMWELL MCDOUGALL, of 68, Port Street, Manchester, Lancashire,
Engineer, and NOEL NEWALL HAIGH, of Plane Street, Oldham, Lancashire,
Engineer, do hereby declare the nature of this invention to be as follows:-
-
This invention relates to that class of filters principally employed in filtering
under pressure feed water for boilers. The source of supply of the feed water
previous to filtration is largely taken from condensation and for that reason is
contaminated to a large extent with oil, and the principal object of the present
invention is to provide certain improvements in feed water filters which while
ensuring efficient filtration under pressure also insures the withdrawal of any
oil present before the filtered water passes to the boiler.
The invention consists generally in providing a vessel within which a cartridge
having an outer perforated shell and containing pulverulent material such as
small coke under pressure is mounted, and in such a manner that an annular
space exists between the outside of the cartridge and the vessel communicating
with the inlet from the unfiltered feed water while a chamber communicates
with a perforated tube placed within the interior of the cartridge for the exit
of the filtered water. This chamber into which the filtered water passes may be
placed at either the top or the bottom of the vessel, but it is preferably placed at
the bottom. A further portion of the invention consists generally in providing
between the final exit of the filtered water and the cartridge a perforated pipe
covered with layers of jute cloth and wire gauze and this perforated pipe may be
arranged in the chamber hereinbefore referred to or may be arranged externally
to the filter in the range of connecting pipe as desired. A further but minor
portion of the invention consists in the mechanical details for replacing and with-
drawing the cartridge, for keeping the pulverulent material under pressure, and
in the arrangement of the inner tube or tubes within the said cartridge.
In carrying the invention into effect according to one modification a cylindrical
vessel is provided having a suitable cover. A cartridge is constructed smaller in
diameter than the vessel and built up of an outer perforated shell with an inner
perforated telescopic or plain tube, the tube of the shell being attached at the
bottom to a stout cast iron or other plate having an annular-faced ring formed
thereon. The space between the inner perforated tube and outer perforated shell
of the cartridge is filled with finely broken pulverulent material such as screened
coke, and the cartridge, when in position beds with its faced ring upon a suitably
recessed ring held in the vessel in such a manner that the vessel itself is divided
up into an annular space between the cylindrical portion and the outer shell of
the cartrridge and into a chamber between the bottom of the cartridge and the
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877

page_text: a
bottom of the cylindrical vessel. The annular space beween the perforated inner
tube and outer shell of the cartridge is open at the top side and comes under-
neath a plate carried by a screw in the cover of the cylindrical vessel, the said
plate having a guide piece which enters the inner tube. It is evident that by
manipulating this screw when the filter cover is closed, the coke within
the cartridge can be brought under pressure and caused to form
compact mass. It is to be understood that the outer perforated shell and the
inner peforated tube of the cartridge may be wrapped with wire gauze of any
desired mesh, and further that the inner tube may have a second tube placed
within it covered with wire gauze and layers of jute or like textile material the
perforations or mesh being so arranged that the finest powderings of the pulveru
lent material cannot pass through.
When a filter constructed as hereinbefore described is in operation the annular
space is connected to the inlet for the unfiltered water which is led thereto under
pressure. As this annular space embraces the whole of the outer surface of the
cartridge the water passes wholly through the thick annular layer of coke within
the cartridge and finally through the inner perforated tube with its layers of gauze
or the like. The water then passes down the tube into the chamber in the vessel
and finally through the exit to the boilers. By regulating the pressure on the
top of the coke or like material the filtering substance is kept from being cut up
into channels and allowing free passage of unfiltered water, as in the present
instance the water is forced to percolate through the whole mass of the body or
coke or like material. The special advantage of arranging the exit for the
filtered water at the bottom of the filter is that any oil which may pass through
would tend to rise to the top, and further that the oil from the water itself
when passing through the filtering medium tends also to pass to the top layer.
A special mechanical advantage of the construction hereinbefore described con-
sists in the arrangement of the cartridge by simply bedding its bottom plate
upon a recessed ring within the filter cylinder and forcing it down into position
by the cover carrying the overhead pressure plate and by the pressure of the said
plates. By this means an exhausted cartridge can be at once readily and rapidly
replaced by a fresh one simply by unbolting the cover and hoisting the cartridge
out.
A further portion of the invention consists in arranging the filter in a compound
manner, that is to say, causing the filtered water when it leaves the inner tube
of the cartridge to pass through a small auxiliary filter consisting of a perforated
pipe covered with alternate layers of wire gauze and jute cloth. This perforated
pipe may be arranged directly within the chamber described in the first modi-
fication and attached to the exit pipe, or it may be arranged entirely external
to the filter itself and fitted for example within the range of piping leading the
filtered water to the boiler. The surface area of this auxiliary filter can be
arranged to correspond to the surface area of the cartridge:
A further modification of the invention consists in arranging the filter in a
multiple manner, with a number of vessels connected up to a common supply
pipe for the unfiltered water and a common delivery pipe for the unfiltered water.
The filtering cartridge in cach of these vessels may be arranged without the
annular coke layer and consist of a plain perforated cylinder with wire gauze
and jute cloth as hereinbefore described, and shut off valves may be attached to
each vessel in such a manner that any one can be isolated from the others for
inspection or renewal of the filtering cartridge.
1000
MARKS & CLERK,
18, Southampton Buildings, London, W.C.,
13, Temple Street, Birmingham, and
25, Cross Street, Manchester, Agents.

page_text: Improvements in and relating to Feed Water Filters.
We, ISAAC SIIMWELL MCDOUGALL, of 68, Port Street, Manchester, and NOEL
NEWALL HAIGII, of Plane Street, Oldham, in the County of Lancaster, Engineers,
'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 follow-
ing statement—
This invention relates to that class of filters principally employed in filtering
under pressure feed water for boilers. The source of supply of the feed water
previous to filtration is largely taken from condensation and for that reason is
contaminated to a large extent with oil, and the principal object of the present
invention is to provide certain improvements, in feed water filters which, while
ensuring efficient filtration under pressure, also insures the withdrawal of any
oil present before the filtered water passes to the boiler.
In the accompanying drawings:-
-
Figure 1 is an elevation partly in section of a filtering apparatus constructed
according to our invention and Figure 2 illustrates the, method of connecting
a number of filters to a common supply.
Referring to Figure 1, A is a cylindrical vessel provided with a flange A¹ to
which is bolted a cover B. Inside of this vessel is fitted a removable filtering
cartridge consisting of an outer perforated shell C. and an inner perforated
tube C which are attached respectively to flanges D and D' formed upon a stout
sole plate E. The space between the tubes C and C is filled with suitably finely
broken pulverulent material such as screened coke. If coke be employed it is
preferably purified by weathering in any suitable manner before use, so as to
remove sulphur. The outer shell C and the tube C¹ may be covered with wire or
jute cloth of any suitable mesh. On the bottom of the sole plate E is formed a
ring E which beds in a recessed ring F supported upon a bracket G attached
to the casing A. The joints between the rings E and F and between the ring
F and the bracket G are provided with packing to prevent the passage of liquid
through them. The interior of the vessel A is thus divided into an annular
chamber surrounding the filtering cartridge C and a chamber beneath the sole
plate E the only communication between them being through the filtering
inaterial.
At the top of the outer perforated shell C of the cartridge is provided a pres-
sure plate H which carries on its under side a perforated guide tube C² telescoping
into the interior of the tube C. This plate is attached to the lower end of the
screwed rod I which passes through the cover B and works in a bridge piece J
supported on the cover. By manipulating the handwheel K the coke within
the cartridge can be brought under pressure so as to form a compact. mass.
The interior of the tube C is fitted with an additional filtering cartridge L
which is constructed of an open framework L' attached at the top to a recessed
end piece fitted with a handle M. The lower end of the framework is fixed
in a ring N which is attached to a short tube 0. This tube is provided with
a flange and screws into the sole plate E. A locking ring nut P holds the
cartridge securely in position with the flange 1 bedding against a packing
washer 02, thus forming a tight joint between the tube and the plate E. The
cartridge is built up by lapping alternate layers of jute or other textile material
and wire cloth, as shown, round the framework L¹. The framework is provided
with rings L (only one of which is shown) at intervals along the cartridge to
form supports for the filtering material. The mesh of jute and wire cloth is of

page_text: sufficient fineness to prevent particles of the pulverulent coke from passing
through. The filtering material is secured at the top and bottom of the cartridge
by clamping rings Q
It is obvious that instead of the framework L' a perforated pipe may be em-
ployed as the foundation of the filtering cartridge.
R is the inlet for the feed water to be filtered from a main supply pipe T,
and S is the outlet for the filtered water. The inlet and outlet pipes are
provided with valves R, S, by means of which the filter can be isolated from the
supply pipe T for cleaning, or for other purposes. The valve T¹ which controls
the passage through the main supply pipe is shut when the filter is in operation.
It is obvious that instead of fitting the cartridge L inside of the tube C¹
it might be placed in the lower chamber of the vessel A with its outlet O con-
nected to the outlet $ of the filter.
By employing an additional filtering cartridge such as L the passage of grit
or finely divided coke to the boiler valves is effectively prevented. We thus
avoid the rapid wear of the valve seats which has hitherto taken place when
coke has been used as a filtering material.
In the arrangement of filters shown in Figure 2 the vessels A are connected
at their inlets to a common supply pipe V and at their outlets to a common
delivery W. A shut off valve is provided on the inlet and outlet of each vessel
so that any one can be isolated for inspection or removal of the filtering cartridge.
When a filter constructed as herein before described is in operation the valves R¹
and S¹ are open and the valve T is shut. The unfiltered water under pressure
from the feed main T passes into the annular space surrounding the cartridge C
and forces itself through the coke layer into the interior of the tube C¹. It is
then further filtered by passing through the layers of jute and wire cloth of the
cartridge L from which it passes down through the tube 0 to the chamber in
the bottom of the vessel and finally through the exit S to the boilers. By
regulating the pressure of the plate H the cutting up of the coke into channels
is prevented and the water is therefore forced to percolate through the whole
compact mass of the coke or other filtering material employed.
By arranging the exit for the filtering water at the bottom of the filter, the
passage to the boiler of any oil or grease which accumulates in the filter is
prevented as the oil, being lighter than the water, rises to the top of the vessel.
The pressure gauge U fixed on the inlet of the filter indicates to the attendant
when the filtering cartridge has become so clogged up, as to offer great resistance
to the passage of the liquid through it, and therefore requires cleaning. When
this takes place the valves R₁ and S¹ are shut, the cover B is removed, and
the cartridge hoisted out. The exhausted cartridge can thus be readily and
rapidly charged with fresh coke and filtering cloths or a fresh cartridge can be
substituted. In Figure 2 the dotted lines indicate a simple device consisting
of two rods X, Y, attached to loose collars VI on the supply pipe V the rod Y
being provided with blocks and tackle for hoisting a cartridge out of the filter.
The collars V admit of the swinging round of the rods X, Y so as to bring
the tackle above either of the filters or to bring a cartridge clear of its containing
vessel so that it may be lowered to the ground.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:
1. In an apparatus for filtering feed water consisting of a containing vessel
divided into two chambers communicating respectively with the inlet and outlet
of the apparatus, and with each other through a removable filtering cartridge,
said cartridge consisting of two concentric perforated shells with an inter-
vening layer of finely broken coke or other pulverulent material, means for
subjecting the material to pressure from without after the filter is closed, sub-
stantially as described.

page_text: 2. In an apparatus for filtering feed water the combination of a removable
filtering cartridge consisting of two concentric perforated shells with an, inter-
vening layer of finely broken coke or other pulverulent material and a cartridge
built up of alternate layers of jute cloth, or other textile material, and wire
gauze, substantially as described.
3. The construction and arrangement of feed water filter substantially as
described, and illustrated in Figure 1, of the accompanying drawings.
4. The arrangement of a number of feed water filters round a common
supply and a common delivery substantially as described and illustrated in
Figure 2 of the accompanying drawings.
Dated
ՎԱՏ ԳՆԱ ua
ՍԱ ARCH
MARKS & CLERK,
18, Southampton Buildings, London, W.C.,
13, Temple Street, Birmingham, and
25, Cross Street, Manchester, Agents.
MARKS & CLERK,
18, Southampton Buildings, London, W.C.,
13, Temple Street, Birmingham, and
25, Cross Street, Manchester, Agents.