Improvements in or Appertaining to Filters for Filtering or Purifying the Feed Water of Steam Boilers and for other purposes.
Year: 1891

page_text: This Print is in accordance with the Original Specification as it stands after
Amendment (under Section 18 of the Patents, &c. Act, 1883), as allowed by
the decision of the Comptroller General of the 15th day of April 1896.
Date of Application, 20th Apr., 1891-Accepted, 6th June, 1891
Improvements in or Appertaining to Filters for Filtering or
Purifying the Feed Water of Steam Boilers and for other
purposes.
I, ANTHONY HARRIS of Middlesborough, in the County of York, Engineer,
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 has for its object a filter applicable for filtering or purifying the
feed water of steam boilers and for other purposes.
The invention is best described by aid of the accompanying drawings, in
which,
Figure 1 is an elevation partly in section of the filtering apparatus as a whole.
Figure 2 and 3 side elevation and section of valve B.
Figure 4 a vertical section of a portion of my filter showing a slightly modified
arrangement.
In these, A is a feed pipo bringing the water from the pump to the boiler or
from the hot well to the foed pumps. (In the latter case, the water would be
sucked through the filter, but the valve would work exactly the same and open
direct communication if the vacuum behind the pump rose about the required
pressure.) B, is a valve weighted or screwed down to open at any given pressure
so that, if the resistance of the filter become more than said given pressure, the
valvo B opens and allows the water to pass through pipe D to the boiler or feed
pump. CC1 and C2 are stop valves. E a ring rivetted to shell and on which the
filter rests. F F F F four layers of flannel having immediately above them
perforated plates G G G G. Between the two sets or pairs of plates G are brass
gratings HH to support and relieve the pressure on the perforated plates G, and
to keep them at the right distances from each other, and by pressing the inner
flannels between the plates G G and the internal shell of the filter, prevent the
filtering medium escaping. II are screws to keep the plates and internal shell G¹
tight. Between the two inner plates G G is a layer of spongy iron. On the top
of the upper plate a perforated bell J is pressed down by means of screw K holding
all tight, especially the two flannel joints where the lower grate and perforated
plato rest on the supporting ledge h. L is a cover for the filter.
Referring to Figures 2 and 3 showing two views of valve B, M is the valvo,
Na spring holding it down, O a gong and P a clapper, Qa collar on the shaft
linked to the clapper of the gong.

page_text: The mode of action of the entire apparatus is as follows:-
The water, being pumped through A, passes through the valve chamber of B,
down the vertical pipe to the filter as long as the resistance of the filter is less than
the pressure to which the valve B is weighted. The moment, however, that that
pressure is momentarily exceeded, the valve M rises, carrying collar with it
and by this means rings the gong. The pulsations of pumping, causing the
pressure to be alternately above and below the resistance of the filter, cause the
spindle of the valve for a time to dance up and down, incessantly ringing the gong.
The attendant, hearing this ringing, at once closes valve C and opeus valve C¹.
The water then, after lifting valve B, rushes into the filter through valve C
cleaning out the dirt which runs off through the valve C¹. The cleansing can be
done, if desired, by means of a pipe and valve such as T specially provided and
connected to the boiler for this purpose. The valve C¹ is again closed, the valve C
opened and the apparatus continues as before. When however, in course of time,
the filter gets so corrupt as to require renewing or altering, the valves C and C³
are closed, the lid L and the bell J of the filter removed, and the filter withdrawn
bodily from its caso. A spare filter, consisting of the parts connected together by
the studs 1, can then be put in its place and the bell J and lid L fixed on as before.
The old filter can now be carefully cleaned or replenished at loisuro.
It will be seen consequently that, although there may be 200 lbs. pressure on the
squaro inch in the boiler, there is nover any more pressure through the filter while
in actual work than what the valve B is weighted for.
Whon, however, the filter is to be cleaned out, the valve C³ can be opened or
throttled to any desired extent and thus any desired pressure put on the filter.
The rosult is that, until the filter is nearly worn out, it is found to be perfectly
self-cleaning.
I prefer spongy iron for the filtering material to charcoal or other like ingredients,
as not merely does it act as a filter and deodorising material, but it also acts instead
of zinc in separating copper from the feed water and thus increases the longevity of
the boiler.
Instead of the spindle of valve B directly actuating the gong, when more
convenient, I attach, to the spindle, a circuit making and breaking device, so as to
ring an electric bell near where the attendant is stationed.
In a slightly modified form of my filter, I dispense with the inner motal chamber
of filter (Figure 1) and confine the spongy iron or filtering material in a flannel
bag R (Figure 4) placed between the two inner perforated plates G, retaining the
grates and flannels as before.
In this case, I exert pressure direct on the flannel bag R, by screwing down the
perforated bell J on to the upper grate by means of a screw spindle K.
In this arrangement, I have the advantage of being able when required to
relieve the pressure of the bag R of filtering material, when the particles get set
too closely together, without allowing them to escape while the filter is working.
The division plate S in front of the valve C (Figure 1) directs the flow of water
across the surface of the lower filtering flannel and tends to detach any particles of
dirt adhering to it and deposits them at the opposite side of division plate in close
proximity to the sludge valve (" ready for removal.
To facilitate the deposition of copper, as the feed water passes through the filter,
I sometimes pass an electric current through the water by means of insulated wires,
connected to any suitable dynamo or battery.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that I am well
aware that relief or safety valves have been used with feedwater filters whereby
when the resistance of the filter becomes excessivo, the water is allowed to escape,
also that it has been proposed to place a relief valve in the filter itself whoroby
when the resistance of the filter becomes excessive the valve opens and the
impurities which have been rejected by the filter and the unfiltered water are

page_text: allowed to proceed together in the boilers. and I make no claim for such valves
my valve being a by-pass valve which when the resistance of the filter becomes
excessive cuts off the filter from the circuit and allows the water to go direct to the
boiler without passing through the filter. I am also aware that gongs, whistles,
and other alarins have been connected with safety valves so that the escaping fluid
shall sound the alarm and I make no claim, for such, my alarm is one attached to a
valve having no escape into the outer air and just operated by the dancing of the
valve itself, but that what I claim is:-
1. In a filter for filtering feed water, the combination of two or more plates
above and two or more plates below, separated from each other by an air space and
lined on the filtering side with flannel, felt or equivalent material and a chamber of
spongy iron or its equivalent, separating the two sets, the whole being pressed
together and arranged with distanco pieces so that undue pressure cannot be
brought to bear upon the filtering material, substantially as described.
2. In combination with a filter for filtering feed water, a valve B weighted to the
required maximum resistance of the filter whereby, no matter what the pressure on
the boiler may be, the required maximum pressure on the filter is not exceeded,
substantially as described.
3. In a filter for filtering feed water, the combination, with a by-pass valve such
as described weighted to the required maximum resistance of the filter, of an alarm
operated by the spindle of the valve, whereby, the moment the maximum pressuro
is exceeded, the valve spindle rises sounding the alarm, substantially as described.
4. The filter and its appurtenances taken as a whole substantially as described
and illustrated.