Improvements in the Method of and Apparatus for Heating and Purifying the Feed-water for Steam Boilers.
Year: 1889

page_text: Date of Application, 26th Nov., 1889-Accepted, 15th Mar., 1890
COMPLETE SPECIFICATION.
Improvements in the Method of and Apparatus for Heating and
Purifying the Feed-water for Steam Boilers.
I, BENJAMIN FRANKLIN FIELD, of Chicago, in the County of Cook, State of
Illinois and United States of America, gentleman, do hereby declare the nature of
my invention for IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR HEATING
AND PURIFYING THE FEED WATER FOR STEAM BOILERS, and in what manner the same
is to be performed, to be particularly described and ascertained in and by the following
statement:
Heretofore it has been customary to supply the waste or consumption of water in
steam boilers by delivering, from time to time, a fresh supply of water into the general
circulation, to compensate for the amount of water discharged or withdrawn from the
boiler in the form of steam.
The feed water thus supplied to the interior of the boiler is usually at a much
lower temperature, when it enters the general circulation, than the water contained
within the boiler, and it is sometimes the practice to increase the temperature of the
feed water, before being discharged, by causing it to pass through heated conduits;
but in either case, whether the water be heated or cold, it is charged more or less
with sediment and scale-producing materials, which, being carried into the general
circulation, eventually attack, or are deposited upon, the exposed surfaces within the
boiler.
Many attempts have been made to obviate this difficulty but it has been found
impossible to accomplish the object at anything like reasonable cost and by the
employment of cumbersome and complicated structures.
By careful tests and close observation I have ascertained that the scale producing
materials are rendered more active, to attack the metal, and the sediment carried by
the water is deposited more rapidly, as the temperature of the water is increased,
and that this action continues so long as the water retains its fluid condition and
until converted into steam; and, further, that by converting the water into steam it
is deprived of these impurities.
This action takes place within the boiler when provided with appliances which
deliver water in liquid form into the circulation, as upon the conversion of the water
into steam within the boiler, the impurities referred to are liberated in contact
with the flues and exposed internal surfaces of the boiler to which they adhere.
My present invention is more especially designed to prevent the entrance of the
impurities into the general circulation of the boiler.
Instead of delivering the feed-water, in liquid form and charged with impurities,
into the general circulation, I make provision for heating the feed-water to the
boiling point within a purifier or conduit, and discharging it in the form of steam
into the steam space, whereby all objectionable substances are caused to be liberated
and deposited within the heater and purifier, and the water is discharged into the
boiler in the form of steam and free from impurities.
This result I accomplish by means of a feed-water heater and purifier of proper
dimensions, located within and having a discharge opening or openings, pipe or pipes,
projecting well up in the steam space and above the water level in the boiler, and
so regulating and proportioning the feeding of the water into the heater, that it will
become beated to the boiling point and be converted into steam therein, and
discharged, as such, into the boiler; whereby, instead of supplying the water in
liquid form, it is introduced into the boiler as steam, leaving all sediment and scale
producing materials within the heater, from whence they are removed, as occasion
demands, by blowing dry steam hack through the interior of the conduit or
heater
"

page_text: Any known form of feed-water heating apparatus may be utilized in carrying my
improved method into effect, providing it is properly proportioned and heated, and
the feed of the water is so regulated as that, before being discharged into the general
circulation, and while still within the heater, the water shall be converted into steam
and the latter delivered into the boiler, inasmuch as the separation of the impurities
from the water while in the heater and the delivery of the water in the form of
steam into the boiler, to supply the waste therein, constitutes the gist of my improved
method.
The preferred form of apparatus for carrying my said invention into practice is
illustrated in the accompanying drawings, although its use is not limited thereto, as
it may be employed, as well, to serve as a heater and purifier where water instead of
steam is delivered within the boiler.
Figure 1 is a longitudinal vertical section, and
Figure 2 a longitudinal horizontal section through a boiler containing my improved
heater and purifier.
Figure 3 is a transverse vertical section on an enlarged scale through the front of
the boiler.
Figures 4 and 5 are detail views illustrating the manner of supporting opposite
ends of the heater.
Figure 6 is a perspective view, partly in section, of a section of the conduit
showing the internal tubes.
Figure 7 is a longitudinal section, and
Figure 8 an end view of one of the conduit sections.
Figures 9, 10 and 11 represent, in perspective, longitudinal section and end view,
a modified form of supports for the internal tubes.
Figure 12 is a detail view showing a section of the check-valve.
Similar letters of reference in the several figures indicate the same parts.
In illustrating the application of my improvements in the heating and purifying
apparatus, I have shown the latter as applied to a locomotive boiler, of the
American type, but do not wish to be understood as limiting myself thereto,
inasmuch as the heater and purifier can readily be adapted and applied to other
forms of boilers, as will readily be understood by those skilled in the art.
Referring to the boiler shown, A designates the shell; B, the flues; C, the fire-
box; D, the crown-bars; E, the stay-rods for the front flue sheet; F, the steam
dome; G, the dry-pipe, through which steam is conducted from within the
boiler to the steam cylinders.; and H, the dry-pipe yoke for sustaining the latter in
.position.
These or equivalent parts are to be found in most forms of locomotive boilers.
Within the boiler is arranged the feed-water heater and purifier, consisting,
essentially, of a long conduit, preferably horizontally disposed and extending lengthwise
of the boiler, through which the feed-water is conducted, and is heated during its
passage through the same.
The conduit 1, is, preferably, constructed in the form of a long tube or pipe,
made in sections, and extending back and forth in a sinuous course, one end of said
conduit being connected to the feed-water devices or pipes, through an intermediate
check-valve or valves, and the other end terminating in a series of discharge pipes
opening above the water line in the steam space.
The induction end of the conduit is formed or provided with an inlet section 22
extending transverely through the boiler, and furnished at one or both ends with a
removable attachment, such as a check-valve 23, communicating with the feed-water
supply or pump.
This inlet section is located in, or nearly in the same plane with the remainder of
the heater, of which latter it forms an integral portion, being wholly within the
boiler, and it is composed of a straight section or sections of pipe, with the check
valves detachably applied thereto outside the boiler, so that, by removing the check-
valves, a clear passage will be left through which the interior of that portion of the
conduit can be viewed from either side of the boiler, to ascertain the condition of

page_text: that portion of the heater, and, in case any obstruction is formed therein, it can
readily be removed.
The inlet section is connected to the induction end of the rest of the conduit
through an elbow or curved pipe, the end next the inlet section being curved towards
one side of the boiler (preferably the right-hand side), the curvature in this inlet-
section being for the purpose of providing an easy outlet for the steam, in blowing-
off for the purpose of cleansing the purifier; and to the end of the inlet section,
on that side, and between said section and the check-valve, is attached the blow-off-
pipe 24.
The preferred plan of connection is shown in the drawings, wherein 25 represents a T
attached to the end of the inlet section, between the boiler and check-valve, and
below it is located a valve with appropriate devices for operating it, to open com-
munication between the interior of the heater and the blow-off pipe.
Heretofore it has been customary to connect the blow-off pipe to the heater and
purifier, between the latter and the check-valve so that in blowing-off no cleansing
action takes place in the check valve, the valve being held tightly on its seat by the
pressure of the steam or water escaping through the heater.
To provide for cleansing the check-valve, particularly the seat and on the under-
side of the valve, I make a connection 26 between the feed-pipe and blow-off pipe,
with a valve therein controlling said connection, and I provide a means for raising
and sustaining the valve of the check-valve above its seat, or in open position, so
that when it becomes necessary or desirable so to do, the steam may be conducted
through the check-valve casing and around the valve therein, into the blow-off
pipe, and be thus caused to operate upon and remove deposits from within the
check-valve.
Should it become necessary or desirable for any reason, such as to prevent back
pressure, to close the feed-pipe while blowing-off, a stop cock may be introduced in
the feed-water pipe in rear of the connection 26.
As illustrating one form of check-valve for my purpose, I have shown, in figure 12,
a valve casing secured to one branch of a T 26, attached to the end of the feed-water
pipe; and beneath the valve, a stuffing box or packing collar 27 is secured to the T,
with a screw stem 28 projecting through the stuffing box in position to engage
and lift the valve from its seat, so as to leave a clear passage for the steam. When
the stem 28 is retracted, the valve returns to its seat, and is not interfered with in its
normal operation.
The main portion of the conduit or heater and purifier 1 is supported within the
boiler independently of the flues, and in order to obviate the necessity for making
special attachments to or otherwise interfering with or impairing the integrity of
the shell, have devised the following novel plan, whereby, not only can the
heater be readily applied, but also adjusted vertically, so as to produce the most
effective action.
To the front stay-rods E, on each side of the dry-pipe G, is attached a clamp or
bracket 5, as, for example, by applying plates 6 on opposite sides of the stay-ro's and
clamping them thereon, by a bolt or bolts 7, so that said clamps or plates may be
readily applied, removed and adjusted.
From the bracket 5 depends a lianger or rod 8 upon which is adjustably secured a
clamp 9 which receives and supports the front end of the conduit. The clamp 9 may.
be constructed and applied in any approved manner; thus in the illustration it is
shown as a bar or plate 10 extending beneath the conduit, and suspended upon the
two rods or hangers 8, one on each side; and the adjustment may be provided for by
threading the roils 8 into the clamp or bracket 5 above, and swivelling them in or
upon the clamps 9 or bar 10, as shown, so that when said, rods are turned, as by the
application of a wrench to their angular portions 11, or by other means, the support
for the forward end of the conduit will be raised or lowered. The conduit may
be retained in position upon the bar 10 by any suitable means, such as a superposed
bar 12 and Lolis 13, these elements, in conjunction with bar 10, forming what is
herein referred to as the clamp 9.

page_text: As it is sometimes desirable to elevate the front end of the conduit to such a degree
that the inner lengths or central portion will stand above the lower face of the
dry-pipe G, the upper member of the clamp 9 may be formed in separate sections,
as shown in figure 4, or provided with a central depression to accommodate the
dry-pipe.
The rear end of the conduit is, in like manner. provided with adjustable suspension
devices, connected to the dry-pipe yoke, or other convenient supports within and
forming part of the boiler proper. Thus, in the illustration, I have shown a clamp
composed of two members 15, 16 detachably secured to the conduit by bolts 17. The
clamp is suspended from brackets 19 attached to the dry-pipe yoke H, by adjusting
rods or hangers 18, and, in the absence of a dry-pipe yoke, the supporting brackets
may be attached to the stay bolts or braces in the rear portion of the boiler.
Provision is also made for adjusting the elevation of the rear end of the conduit,
as by making the hangers 18 adjustable with relation to the clamp or bracket.
As is obvious other well known forms and constructions of adjustable connections
or hangers may be employed, in lieu of those shown, for raising and lowering the
conduit, the essential feature of this part of my invention residing, primarily, in the
application of suitable means for suspending the feed-water heater and purifier-
represented by conduit 1-within the boiler, and above and independently of the flues,
upon the stay-rods and dry-pipe yoke, or other internal supports usually present within
the boiler. If, however, it should be deemed desirable to do so, the brackets to which
the adjustable hangers are connected may be applied directly to the shell of the
boiler.
To assist the hangers in retaining the conduit in place, and to prevent the twisting
and bending of said hangers and restrain longitudinal movement of the conduit, I
attach to the rear end, and, preferably, to each of the outside connections 4, a yoke or
clamp 21 extending rearwardly over the crown-bars D, and provided with a stud or
projection engaging the sides of the crown-bars.
The conduit 1 in the form shown, although applicable to new boilers, has been more
especially designed for insertion within locomotive boilers that have been in use,
hence special provisions have been made for facilitating the insertion of the feed-water
heater and purifier, which operation is usually performed when the boiler is laid up
for cleaning and repair. At such times it is customary to withdraw the dry-pipe and
remove the flues, the latter being drawn out through the opening for the dry-pipe in
the front flue-sheet. The flues are removed in order that they, as well as the inner
surfaces of the boiler, may be cleaned of scale and sediment, and to permit the
workman to enter the boiler for the purpose of removing the crown-bars or make
other repairs.
While the flues are withdrawn the feed-water heater and purifier is introduced and
adjusted in position, and in order to provide an exit for the workman, as well as to
afford space for him to stand while operating upon the crown-bars, I make the central
portion or section of the conduit 1 shorter than the flues, so that a space will be left
between the rear end of the conduit and the rear flue-sheet, through which the workman
can pass from beneath the conduit to the space above the fire-box, and in which
he can stand while operating upon the crown-bars or making repairs at this end of
the boiler.
In order that the length of the conduit may not be materially diminished in
consequence of this shortening of the inner or central section, the outer sections are
prolonged somewhat by carrying them close to the boiler, with the rear ends of said
sections curved or bent on diverging lines following the enlargement of the boiler at
this point. A wider space is thus formed between the rear ends of the outer sections
which may be utilized by the workman in making repairs at this end of the boiler,
such as could not otherwise be made without removing the purifier or some portion
of it.
The eduction end of the conduit is formed or provided with a discharge opening or
openings of relatively large area, (preferably two or more discharge pipes are employed)
and said discharge opening or openings are arranged to stand well above the water

page_text: line, in the steam space, so that the water in the boiler will be prevented from flowing
back or mingling with that contained in the heater and purifier, and, also, to prevent
the water from entering the conduit while blowing-off, to clear the latter, in effecting
which operation steam is employed and is much more effective than water.
The improvement pertaining to the apparatus, as thus far described, relate solely to
its external form, arrangement and mounting, and are applicable to various descrip-
tions of feed-water heaters and purifiers without special reference to the internal
construction of the conduit.
I have, however, devised certain improvements relating to the internal construction
and arrangement of the conduits of feed-water heaters and purifiers, such as described,
and which, when employed in connection with my other improvements, produce
very beneficial results. The improvements referred to are more especially designed to
facilitate the heating of the feed-water and the separation of the impurities therefrom,
and they are rendered of special value and utility when the apparatus is so operated
that the feed-water is delivered into the boiler in liquid form, instead of being wholly
converted into steam in the heater and purifier, and discharged in the form of vapor
into the boiler.
As hereinbefore mentioned, the conduit 1 is preferably constructed in sections
detachably connected together, to form a continuous conduit or channel through which
the feed-water is conducted.
The interior of some or all of the sections is divided by thin metal partitions
into a series of longitudinal channels or passages, connected together through
perforations or slots in said partition so as to permit a free circulation of the
water.
Such channels as are referred to may be formed by the introduction into the
sections of the conduit, of a series of tubes 20 (plain or corrugated or part plain and
part corrugated) of different diameters, placed one within another or nested, and held
apart by suitable devices, such as cross-bolts, and washers, or by spiders 31 applied to
the ends of the series of tubes and clamped in position thereon by a through rod 32
having appropriate fastenings and held from longitudinal motion by a cross-bolt 30 or
equivalent means.
In order to obtain increased surface area, some or all of the tubes 20 may be
corrugated thus in the example given in figures 6 to 8 alternate tubes of the
series are shown corrugated, and all of the tubes are provided with slots or
perforations.
The preferred construction is shown in figures 9 to 11, wherein, instead of employing
cylindrical tubes and perforating them, the tubes are formed from sheets, properly
perforated to provide the upper series of openings, and bent partially into tubular
form without, however, bringing the edges together, but leaving a slot or space along
this side, which constitutes the botton portion of the tube when in place, said slot
serving to permit the sediment to fall to the bottom of the conduit, and, also to
facilitate the free circulation of water in the conduit. The partial tubes thus formed
are held and retained in the proper relative positions by the spiders applied to the
ends and connecting bolts.
The series or nest of internal tubes may occupy the full length of the section of
the conduit to which they are applied, but I prefer to make them shorter than the
section, so as to form settling chambers at each end, and in the induction end of the
section I locate an abutment 3 whose upper face is inclined, as shown, in the direction
in which the feed-water is conducted when feeding. The front end or face of this
abutment operates to check or retard the movement of sediment along the lower
portion of the conduit and to retain it at different points in the conduit beyond or
between the internal plates or partitions of contiguous sections, thereby serving not
only to definately locate said deposits and prevent the injurious matter from being
carried forwards into the boiler, but, also, to aid in keeping the passages between the
internal tubes substantially clear of sediment. The abutments are formed with
inclined faces so as to offer the minimum obstruction to the flow of the feed-water,
and, also, to facilitate the operation of blowing-off.

page_text: The operation of this improved form of heater and purifier is as follows:-
The cross sectional area of the passage or passages in the conduit greatly exceeds
that of the feed-pipe, hence the movement of the water in the heater is much slower
than in the feed-water pipe. In its passage through the conduit, the temperature of
the water is gradually increased, whereby the scale-producing materials or salts are
liberated or rendered active, and the sediment is precipitated. Ordinarily the water
is discharged into the boiler while in this condition, and, as a result, the active scale-
producing materials, separated or rendered active in the heater, are delivered into
the general circulation of the boiler, and at once begin to be deposited upon or attack
the exposed surfaces of the flues and shell of the boiler.
It is with a view to providing protection for the interior of the boiler, by localizing
the action of the scale producing substances and confining them within the conduit,
that I introduce the tubes or partitions within the conduit, to afford a large surface
area of metal to the direct action of these active scale pro.lucing materials, so that the
latter will be withdrawn from the water and deposited upon or within the conduit
before reaching the discharge orifice.
The stream of water flowing through the conduit is subdivided by the tubes or
partitions, and distributed over the surfaces of the latter in a manner to facilitate
the formation or deposit of the active salts and other materials, so that, when the
water reaches the discharge orifice or is delivered into the boiler, it will have been
deprived of its active elements and rendered practically inert so far as the formation
of scale is concerned.
By providing the internal partitions or tubes with perforations or slots, not only is
the flow of the water equalized, and the steam formed in the various passages
permitted to ascend while the deposits descend, but the area of metallic surface in
direct contact with the water is increased.
When it is desired to clean the conduit of sediment, the passage into the blow-off
pipe at the induction end of the heater and purifier is opened, and the steam from the
steam space is permitted to escape through the conduit, driving out all sediment and
impurities which have been deposited within the conduit.
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:
1. The hereinhefore described improved method of feeding steam boilers which
consists in converting the feed-water into steam in a conduit within the boiler and
discharging it in the form of steam into the steam space, whereby the impurities are
excluded from the general circulation and retained in the heater or conduit; substan-
tially as described.
2. In combinat on with a steam boiler and the feed-water supply appliances thereof,
a conduit, preferably as described, so arranged and disposed within the boiler, and so
proportioned to the capacity of the boiler and to the feed-water supply that the feed-
water shall be retained in the conduit until it is converted into steam, and discharging
the steam into the steam space in the boiler.
3. In a feed-water heater and purifier, the conduit provided with a series of
internal tubes supported upon spiders held in place by a tie rod, substantially as described.
4. In a feed-water heater and purifier, the conduit provided with a series of slotted
and perforated tubes, substantially as described.
5. In a feed-water heater and purifier; the combination with the conduit and the
internal tubes arranged one within another, of the spiders located at the ends of the
series of tubes and provided with retaining shoulders, and a tie-rod connecting said
spiders; substantially as described.
6. In a feed-water heater and purifier, the combination with the conduit of a series of
metal sheets bent into tubular form, but with their edges separated to form longitudinal
slots and provided with openings in their upper sections, said tubes being of different
diameters and arranged one within another, and supported within the conduit with
the slotted portions opening downwards; substantially as described.

page_text: 7. In a boiler, and in combination with a feel-water heater an 1 parifier, located.
therein above the flues, an inlet section of the heater, said inlet section passing
in a direct line transversely through the boiler and connected to the feed-water
supply.
8. In combination with a boiler and a feed-water heater located therein, an inlet.
section of the heater at the induction end, passing in a straight line through the boiler,
with check valves detachably secured to the ends of said section outside the boiler;
substantially as described.
9. In combination with a boiler, and a feed water heater and purifier located therein.
above the flues, and having its discharge openings projected into the steam space,
an inlet section extending transversely through the boiler and connected to the
induction end of the latter by a laterally curved connection; substantially as
described.
10. In combination with a boiler, a conduit horizontally disposed and extending
back and forth above the flues, one end of said conduit being provided with a discharge
pipe or conductor vertically inclined and opening into the steam space, and the
opposite or induction end connected to a transverse section of the heater extending.
through the shell of the boiter in or nearly in the plane of the conduit; substantially
as described.
11. In a boiler, and in combination with the inlet section of the heater, a check:
valve interposed between the feed pipe and said inlet section and provided with
appliances for holding the check valve open, and a connection between the feed pipe
and blow-off pipe, whereby, by raising the valve and opening communication with the
blow-off pipe, the steam will be driven through the check-valve, to clear the latter ;.
substantially as described.
12. In a boiler, and in combination with the inlet section of the feed-water heater,.
and the feed pipe, a check-valve, interposed between the feed pipe and said inlet
section, provided with a lifting stem, and a connection between the feed-pipe and
blow-off pipe controlled by a valve; substantially as described.
13. The combination, in a feed-water purifier, such as described, of a conduit
through which the water is conducted to the boiler, located within the latter, and
provided with plates or abutments as at 3 located at intervals in the length of
the conduit, and in the lower section of the opening therein, substantially as
described.
14. The combination, to form a feed-water heater and purifier, such as described,
of a conduit located within the boiler and provided with internal tubes or plates
arranged at intervals in the length of the conduit, with retarding plates occupying the
lower portion of the conduit and arranged in the spaces between contiguous groups
of internal tubes or plates; substantially as described.
15. A feed-water heater and purifier, such as described, consisting, essentially, of a
series of tubular sections united together and provided with shorter internal tubes or
plates and an inclined-face abutment 3 located in the induction end of the section ;
substantially as described.
16. The combination, to form a feed-water heater and purifier for application within
the boiler, of a series of sections united together to form a continuous conduit, the
sections forming said conduit being provided with a series of shorter perforated tubes
beld separated, and removed from the ends of the section to form chambers therein,
with an inclined faced-plate or abutment 3 located in the induction end of the section ;
substantially as described.
17. In combination with a locomotive boiler, a feed water purifier and beater
suspended above the flues upon the stay rods and dry-pipe yoke; substantially as
described.
18. In combination with a locomotive boiler, such as described, a feed water
heater and purifier suspended by adjustable supports at opposite ends upon the stay
rods and dry pipe yoke or equivalent supports within the boiler; substantially as
described.
19 In combination with a locomotive boiler, a feed-water heater and purifier

page_text: suspended above the flues upon adjustable and removable supports indirectly connected
to the shell of the boiler above the flues; substantially as described.
20. In combination with a locomotive boiler such as described, a feed water heater
located within the boiler above the flues, clamps removably applied to the heater at
or near the ends thereof, and adjustable hangers or supports interposed between the
stay rods and clamp at one end, and the dry pipe yoke and clamp at the opposite end;
substantially as described.
21. In a locomotive boiler such as described, and in combination with the flue-
sheet, stay rods and the dry-pipe yoke, brackets provided with adjusting rods and
connected to clamps, the latter detachably applied to the feed-water heater, to
support and adjust the position of the heater above the flues; substantially as
described.
22. In combination with a locomotive boiler such as described, a conduit
extending longitudinally of the boiler above the flues and supported at each end
within the boiler, and an independent adjustable support for the discharge end of
the conduit; substantially as described.
23. In combination with a locomotive boiler such as described, a feed water conduit
horizontally disposed and suspended above and independently of the flues, the central
section of said conduit terminating at a point sufficiently in advance of the rear flue
sheet, to form a passage for the workman, substantially as and for the purpose
set forth.
24. In combination with a locomotive boiler such as described, a feed water conduit
suspended within the boiler above and independently of the flues, said conduit com-
prising a number of lengths of pipe connected together at opposite ends alternately,
the outer lengths being bent or curved on diverging lines, and the intermediate lengths
terminating at some distance in advance of the rear flue sheet, to form a space or
passage for the entrance and exit of the workman from within the boiler while the
feed-water heater is in position, substantially as described.
25. In combination with a locomotive boiler such as described, a feed water heater
suspended on hangers above the flues and provided at the rear end with a brace or
braces engaging the crown bars; substantially as described.
26. In combination with a locomotive boiler such as described, a feed-water heater
suspended above the flues and provided with a removable clamp or clamps applied to
its rear end and extending above the crown bars, said extensions being provided with
a lug engaging the sides of the crown bars, to prevent longitudinal movement of the
heater; substantially as described.
Dated this 26th day of November 1889.
W. P. THOMPSON & BOULT,
Agents for the Applicant.