An Apparatus for Precipitating Solid Matter from and for Filtering Feed Water for Steam Boilers.
Year: 1898

page_text: Date of Application, 16th July, 1898-Accepted, 22nd Oct., 1898
COMPLETE SPECIFICATION.
An Apparatus for Precipitating Solid Matter from and for Filtering
Feed Water for Steam Boilers.
I, WILLIAM DOUGHERTY, Boiler Maker, residing at Chester, in the County of
Delaware and State of Pennsylvania, in the United States of America, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
Referring to the accompanying drawings wherein like numbers designate like
parts throughout the several views, Fig. 1 represents a side view, the shell of
my invention and that of the boiler being in vertical section. All of the piping,
with valves and connections, is shown, part being in section to exhibit the operative
difference between the check valves. Fig. 2 represents a plan view of one of the
similar spray heads, and Fig. 3 shows a modified form of the spraying devices,
in vertical section.
My invention relates to that class of steam boiler attachments in which the
feed water, on its way to the boiler, is received and held temporarily in an inde-
pendent exterior settling chamber maintained at approximately boiler temperature
and pressure for the purpose of depositing by heat all impurities liable to cause
incrustation.
The object of my invention is the production of an improved precipitator and
filter, of simple and durable construction, especially accessible for cleaning and
repairs, in which steam directly from the boiler, and feed water from heater,
pump, or injector, are caused to meet in opposing sprays thereby breaking the
water into minute globules and violently agitating it before reaching the com-
parative calm of the settling chamber, from which it is served through a suitable
filter by gravity to the boiler.
I accomplish the object stated by employing a cylindrical shell supported
higher than the boiler, and introducing in the upper portion of the shell per-
forated pipes arranged to spray live steam and feed water, oppositely, the lower
part of the shell constituting the settling chamber. There are also provided
adequate boiler and other connections, scum and mud blow-off pipes, water-gauge,
and valves to govern the fluid distribution as desired. Each constituent element
of my invention is described in detail and its individual office, together with the
mode of operation of the whole, fully explained hereinafter.
Considering Fig. 1, numeral marks the boiler cylinder, 2 the flues, and 3
the dome. Raised somewhat above the boiler is a properly supported brick-work
covering 4, which forms the top of a return passage 5, immediately over the boiler
leading at the right into a stack or uptake in the common manner.
indicate the path of heated products of combustion.
The arrows
Numeral 6 designates the shell of my invention. As hereinbefore stated, and
as shown in Fig. 1, shell 6 is suitably supported somewhat higher than the
boiler 1. From dome 3 extends pipe 7, usually provided with cut-off valve 8
and terminating in a T 9, coupled to branch pipes 10 and 11, the former passing
through the top of shell 6 and ending in spray head or nozzle 12, see Fig. 2,
CDQ11

page_text: Imme-
the latter passing through the side of the shell and ending in head 13.
diately above head 13 will be noted a perforated diaphragmn 14, which aids in
dividing the falling water, and between the diaphragm and head 12 is a third
spray head 15, terminating the feed water pipe 16 which enters shell 6 above
branch 11. The spray heads are usually of similar design, and I occasionally
fashion heads and diaphragm in conical shape as represented in Fig. 3.
certain circumstances I may omit diaphragm 14, within the purview of my
invention.
Under
After leaving the shell, pipe 16 is provided with a cut-off valve 17 and check
valve 18 opening inwardly. Steam or water passing check valve 18 cannot,
therefore, return. As ordinarily constructed, pipe 16 is given one or more turns
longitudinally in the passage 5 above the boiler, enabling it to act as a feed
water heater. I do not, however, confine myself to this arrangement, as any
efficient heater may be introduced. From passage 5 pipe 16 is led to the pumps.
At some point before pipe 16 finally leaves passage 5 it is interrupted by a T
from which arises pipe 19 having check valve 20 opening downwardly as shown.
Pipe 19 enters the bottom of shell and terminates in a curved portion bent
downwardly, in order that falling impurities may not be again introduced into
the feed water by the intermittent circulatory action to be explained later. That
portion of pipe 19 within shell 6 stands wholly in the settling chamber part of
my invention and hence its mouth must be guarded from descending solid matter
as stated.
There are two discharge pipes leading from shell 6, one, 21, opening centrally
through the bottom and possessing valve 22, the other, 23, passing into the shell
at a distance above the bottom, predetermined as the desired depth of water, in
the settling chamber, and ending in a perforated pipe or skimmer 24, the office
of which is to collect the surface scum from the settling chamber. Pipe 23, is
furnished with valve 25. Pipe 21 blows off the deposit of solid particles, and
joins with pipe 23 in a common outlet pipe 26 below.
Numeral 27 marks a box, closed at the top, supported within shell 6, and
extending somewhat above the surface of the body of settling water.
A per-
forated bottom 28 is given the box and a filtering plate or stratum 29 rests upon
the inner surface thereof. The diverging mouthpiece of the boiler feed-pipe 30
is situated within box 27 upon a level with perforated pipe 24, and, it is, my
practice to cover the mouth of pipe 30 with an open-ended bell 31, suspended
within the box, and having slotted walls as shown, although the bell is not
essential. Boiler feed-pipe 30 passes out, through the bottom of shell 6 and into
the boiler proper, terminating in a perforated portion 32 as commonly made.
A suitable water gauge, not shown, is usually attached to shell 6.
Assume the boiler to be steaming and the settling chamber to be filled by the
pump through the heater and pipe 16 until the water rises above the mouth of
pipe 30. The pressure being equal throughout by reason of the dome connection,
the water will pass by gravity through pipe 30 into the boiler. Let the pump, be
stopped. There is now no longer a mechanically forced circulation through the
heater portion of pipe 16. As soon, however, as the water in the vertical portion
of pipe 16 is so far expanded or vaporized as to rended it lighter than the column
of water, bulk for bulk, in pipe 19, the water in the latter descends through
check valve 20. A sort of intermittent circulation is thus set up which is found
to be perfectly protective of those portions of pipe 16 subjected to direct heat in
passage 5.
In practice it is my custom to attach, box 27 to one side of shell 6, and to pro-
vide a hand-hole 33 affording manual' access to the box for the arrangement
and renewal of the filtering stratum. The opening in the side of the filter
chamber or box 27 is larger than the hand-hole plate which is thus brought
directly against the interior of shell 6, or in contact with a seat prepared for it
and attached in the usual manner. A second hand-hole 34 in the bottom of the
shell permits the removal of matter deposited in the settling chamber which may,,
not be ejected through blow-off pipe 21.

page_text: It is usual also, in setting up my invention, to run a steam pipe 35 from the
dome, or in any convenient manner, connecting it with feed water pipe 16 near
shell 6 as shown, and providing a cut-off valve 36. The office of pipe 35 is to
transmit steam to spray head 15 for the purpose of clearing out its perforations
periodically. Either of the blow-off pipes 21, 23 may be employed as an outlet
during this operation, if required.
I am aware that boiler cleaners of this character in which the feed water,
heated by steam, is caused to throw down its solids, have been constructed, and
I do not claim that feature broadly.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
Claim 1. In a feed water precipitator and filter, the combination of a shell, a
feed water pipe entering the upper portion of the shell and terminating in a
spray head, a steam pipe, upper and lower branch pipes connected with said
steam pipe, said branch pipes entering said shell and terminating in spray heads
one above and one below the spray head of said feed water pipe, the spray heads
of said branch pipes arranged to discharge towards each other, a scum blow-off
pipe, a bottom blow-off pipe, a box supported within said shell and having a per-
forated bottom, a filter situated within said box, and a boiler feed-pipe having
its mouth within said box, said piping provided with suitable valves, substantially
as described.
2. In a feed water precipitator and filter, the combination of a shell, a feed
water pipe entering the upper portion of the shell and terminating in a spray
head, a steam pipe, upper and lower branch pipes connected with said steam
pipe, said upper branch pipe entering the upper portion of said shell and terminat-
ing in a spray head, said spray heads arranged to discharge towards each other,
a perforated diaphragm secured beneath said spray heads, said lower branch pipe
entering said shell and terminating in a spray head arranged below and adapted
to discharge towards said diaphragm, a scum blow-off pipe, a bottom blow-off
pipe, a box supported within said shell and having a perforated bottom, a filter
situated within said box, and a boiler feed-pipe having its mouth within said
box, said piping provided with suitable valves, substantially as described.
3. In a feed water precipitator and filter, the combination of a shell, a feed
water pipe entering the upper portion of the shell and terminating in a spray
head, a steam pipe connected with said feed water pipe, a steam pipe having
upper and lower branches, said upper branch pipe entering the upper portion of
said shell and terminating in a spray head, said spray heads arranged to discharge
towards each other, a perforated diaphragm secured beneath said spray heads,
said lower branch pipe entering said shell and terminating in a spray head
arranged below and adapted to discharge towards said diaphragm, a scum blow-
off pipe, a bottom blow-off pipe, a box supported within said shell and having a
perforated bottom, a filter situated within said box, hand-holes affording access
to said box and shell, and a boiler feed-pipe having its mouth within said box,
said piping provided with suitable valves, substantially as described.
4. A feed water precipitator, consisting in the combination of a feed water
heater having an inlet pipe adapted for connection with a pump or feed water
source, a shell supported higher than said feed water heater, a pipe connected
with the outlet of said heater and terminating within the upper portion of said
shell, a circulation pipe connected with the inlet pipe of said feed water heater
and terminating within the lower portion of said shell, said circulation pipe
having a check valve opening from said shell, a boiler feed pipe terminating
within the lower portion of said shell, the mouth of said boiler feed pipe opening
within the shell above the level of the mouth of said circulation pipe and below
the mouth of the pipe from the heater outlet, said shell provided with blow off
pipes, substantially as described.

page_text: a
5. A feed water precipitator, having in combination with a boiler, a feed water
heater, a shell supported higher than said boiler and feed water heater, a feed
water pipe connected with the outlet of said heater and entering the upper por-
tion of said shell, said feed water pipe possessing a check valve opening towards
the shell, a circulation pipe entering the lower portion of said shell and having
check valve opening from said shell, said circulation pipe connected near the
inlet of said feed water heater, a steam pipe connected with said boiler and
entering the upper portion of said shell, a boiler feed pipe entering the lower
portion of said shell and passing into said boiler, said shell provided with pipes
arranged to discharge scum and deposited matter, the piping having suitable
cut-off valves, substantially as described.
6. A feed water precipitator and filter, having in combination with a boiler,
a feed water heater, a shell supported higher than said boiler and feed water
heater, a feed water pipe connected with the outlet of said heater and entering
the upper portion of said shell, said feed water pipe possessing a check valve
opening towards the shell, a circulation pipe entering the lower portion of said
shell and having a check valve opening from said shell, the mouth of said circula-
tion pipe within said shell opening downwardly, said circulation pipe connected
near the inlet of said feed water heater, a steam pipe connected with said boiler
and entering the upper portion of said shell, a box supported within said shell
and having a perforated bottom, a filter situated within said box, a boiler feed
pipe entering said shell and box and opening above said filter, said feed pipe
passing into said boiler, said shell provided with pipes arranged to discharge
scum and deposited matter, the piping having suitable cut-off valves, substan-
tially as described.
Dated this 24th day of June 1898