Improvements in Water Tube Steam Boilers.
Year: 1894

page_text: Date of Application, 26th June, 1894-Accepted, 4th Aug., 1894
COMPLETE SPECIFICATION.
Improvements in Water Tube Steam Boilers.
I, WILLIAM THOMAS WHITEMAN, of No. 7 Staple Inn, in the County of
Middlesex, Patent Agent, do hereby declare the nature of this invention, (a
communication to me from abroad by John Wesley Van Dyke, Manufacturer, a
citizen of the United States of America, residing at Lima, in the County of Allen
and State of Ohio, one of said United States) and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement :-
This invention relates to steam-generating boilers in which a circulation of water
is maintained through tubes exposed to the fire or products of combustion in con-
tradistinction to fire-tube boilers in which the products of combustion are passed
through flues immersed in or surrounded by the water to be heated.
In accordance with said invention water tubes and headers are so arranged and
adapted as to form lower and higher level circulation rings closed on themselves
but communicating with each other and this intercommunicating ring system of
water tubes is made to constitute or form part of the rising leg of an inverted siphon
which opens at both ends into the water space of a steam and water drum elevated
above the upper part of said system and whose descending leg is constituted by an
independent return conduit communicating with the lower part of said system.
To constitute said intercommunicating ring system, oppositely inclined water
tubes are arranged at different levels and are connected at one or both ends with
headers through which extend vertical passages of a section corresponding with the
water tubes; and the system thus constituted is combined with a steam and water
drum elevated above the upper part of said water tube system and connected
therewith, and with an independent return conduit extending from the water space
of said drum to the lower part of said water tube system, a mud drum being
preferably but not necessarily interposed between the lower end of the said return
conduit and the lower part of the water tube system.
Thus the water space of the elevated drum as well as the water tube system and
return conduit being filled with water, and the boiler being heated, there is a
general circulation through the whole boiler due to the greater density of the water
in the return conduit and elevated drum over the fluid (consisting of more highly
heated water and steam) in the water tube system, which general circulation
descends from the elevated drum through the return conduit and ascends to it again
through the water tubes system; and in this ascending portion of the general circu-
lation there are subordinate circulations at higher and lower levels, which may be
roughly described as respectively descending through the header passages and rising
through the inclined water tubes, but which intercommunicate and are influenced and
modified by the pressure of the heavier water column in the return conduit and the
inflow of water therefrom and by the liberation of steam at the ends of the water
tubes.
By these means there are secured great heating capacity with quietness and
uniformity of operation, and the avoidance of the detrimental geyser action.
The most advantageous arrangement (and a special improvement) is to connect
the oppositely inclined water tubes at both ends with headers having the through
passages of corresponding section.
It is also more advantageous to use in the new or improved boiler, headers made
flexible by being composed of box-like castings connected together by tubular con-
nections, pipes or nipples, than to use more rigid headers, although these might be
used and still be within the more general improvements. The boiler with flexible

page_text: headers is less liable to injury from expansions and contractions, and the arrange-
ment using flexible headers constitutes a special improvement.
Further, in accordance with the invention the oppositely inclined water tubes
arranged at different levels and connected at one or both ends with the headers having
vertical passages through the same, which correspond in section with the water
tubes, are placed lengthwise of and below the elevated steam- and water-drum
whose lower part is exposed to the fire, and the upper part of one end of this
water tube system is connected with one end of said drum, while the lower part
of the opposite end of this water tube system is connected with the lower end of
the independent return conduit which descends from the opposite end of the steam-
and water-drum.
In carrying out the invention the steam- and water-drum may be placed level, or
any suitable arrangement of the same could be employed without exceeding the
limits of such invention; but it is advantageous, and a special improvement, to
arrange the said drum so as to incline downward towards the point from which the
independent return conduit leads to the lower part of the water tube system.
The invention also comprises the particular constructions and arrangements
illustrated in the drawings and hereinafter described with reference thereto.
In the accompanying drawings which form part of this Specification and illustrate
what is considered the best mode of carrying the invention into effect,
Fig. I is a central, vertical, longitudinal section of a water tube boiler constructed
in accordance with the invention,
Figs. I and III are respectively a front and a rear elevation of the same boiler,
showing the ends of the boiler with front and back plates removed and also some
of the covers of the headers, and
Fig. IV is a central, vertical, longitudinal section of a somewhat modified water
tube boiler, also in accordance with the invention.
A
Below the water and steam drum A are the water tubes B B', oppositely inclined
and arranged one above another and connected with the headers. As shown the
headers at both ends are provided with vertical through passages, formed in the
boiler of Figs. I-III by the cavities of the header boxes C and the bores of
the connecting nipples C forming vertical connections between the said boxes. In
the boiler of Fig. IV the vertical through passages are formed by the cavities
of the header boxes C* which extend the full height of the water tube space.
single header box of proper size could be used at each end of the water tubes.
The headers at both ends open into the steam and water drum A, but only the
headers at the front of the boiler are shown as opening directly into the said drum,
the rear headers communicating at the top with said drum through the upper,
water tubes B. If desired the through passages (or through passage if a single
header box were employed) could be used at one end only of the water tubes
(either front or rear as preferred) and any suitable connection between the drum A
and the vertical through passages (whether employed at one or at both ends of the
boiler) could be adopted without exceeding the limits of the invention. There are,
however, advantages in the arrangement shown of having the upper parts of the
through passages (or passage) communicate with the opposite end of the steam and
water drum A from that from which the water passes to the lower parts of the said
passages; and while a level drum could be used, there are also advantages in such
arrangement in having the steam and water drum A set in an inclined position with
the receiving end (at which the hot water and steam enter) higher than the
discharging end (at which the water leaves the drum to pass-to the lower parts of
the water tube system).
The lower parts of the passages which extend vertically through the headers,
are connected with the steam and water drum A by the pipe D independently of
the water tubes (or of most of them, for as shown the through passages of the front
headers are connected with the pipe D through the lower water tubes B).
Other suitable arrangement of an independent conduit between the lower parts of
the headers (direct or somewhat indirect) could be adopted for one or both ends of

page_text: the boiler without exceeding the limits of the invention; there are, however,
practical advantages in the arrangement shown.
The mud drum E is interposed between the pipe D and the water tubes, and is
adapted to retain such sediment as may be carried with the water..
As shown in all the figs. the adjacent water tubes in each vertical row are
oppositely inclined, and this particular arrangement is advantageous as it secures the
most direct circulation (although all my claims are not restricted thereto, for other
arrangements are evidently possible having sufficient similarity to that shown to be
within my more general claims).
In Figs. I-III the headers at each end of the oppositely inclined tubes are
made flexible, or yielding under the expansions and contractions of the boiler, by
being composed of box-like castings Ċ with connecting nipples C¹. The several
header boxes it will be observed receive oppositely inclined water tubes B B¹.
As shewn in these figs., moreover, the header boxes C are equal in height only to
a fraction of the space for the water tubes, and they are separated from each other
and held apart at a suitable distance to give the desired inclination to the said
tubes by the connecting nipples C¹ which are made of a length suitable for that
purpose. The use of this length of nipples is, however, a distinct improvement and
is not essential to the formation of flexible headers.
The front end of the drum A rests upon the hollow casting F from which
suspension links 2 extend to the cross beam supported by the vertical beams 4.
There are tubular nipples 5 between the casting F and the top row of header
boxes C or tops of header boxes C*. The header boxes have detachable cover
plates 6 through which access is given to the interior of said boxes and of the water
tubes for cleaning purposes.
It is preferred to have a number of parallel headers
or boxes at each end of the water tubes, each header or box to be of a width to
receive say two water tubes, as shown for the boxes C in Figs. II-III. There
would thus be half as many boxes C or full height headers C* widthwise of the
boiler as there are vertical ranges of water tubes. At G is the fire chamber with
bridge wall H, and K L are deflecting walls for causing the products of combustion,
to pass oftener over the water tubes, before they escape by the chimney M. At N
and P are frames to doors through which access is had to the boiler within.
To facilitate the discharge of ashes or mineral matter which may be carried from
the fire chamber with the products of combustion, an ash collecting chamber with a
sloping bottom Q is provided below the bridge wall H and below the chimney M
(or chimney port), the slope inclining downward to the door R in the rear wall of
the boiler casing. By the arrangement shown of deflecting walls, so that the
products of combustion are deflected downward toward the said slope, the
collection of mineral matter thereon is favored.
In operation the boiler is kept filled with water to a suitable level in the elevated
drum A (the water tubes B B, headers C C or C*, and return conduit D being of
course filled) and the flames and products of combustion pass over the water tubes
and lower part of the drum A. From the latter the water descends through the
return conduit D and (after depositing any sediment which it may hold in the mud
drum E) enters the lower part of the water tube system. After passing through
the lowermost water tubes any steam which may be formed is liberated in the front
headers to pass directly to the drum A, and the water enters the next horizontal
row of oppositely inclined water tubes B' wherein it is further heated. On entering
the rear headers from said tubes, the water is influenced by the pressure of the
water flowing in from the return conduit D, by the difference in gravity of its own
particles as the same have been more or less heated in traversing the inclined water
tubes, and by the difference in density between respectively the steam and water in
the pairs of water tubes B B' and the water in the corresponding parts of the rear
headers; and according to the balance of these forces, the water may divide into a
more highly heated portion passing upward to and through the next higher level
ubes B to be still further heated and a less heated portion descending to pass again

page_text: through the lowermost and next higher water tubes with fresh water from
the return, conduit. There is also a liberation of steam in the rear headers,
which passes directly upward to enter the drum A by way of the topmost water
tubes.
Inasmuch as in the boilers shown the oppositely inclined water tubes B B are
connected at both ends with headers having vertical through passages, the division
of the water into ascending and descending portions and the liberation of the steam
may take place (as shown) at the upper end of any of the inclined water tubes B
or B', except that there can be no division of water at the upper ends of the lower-
most tubes by the descent of a portion of such water and when the tops of the rear
headers are connected with the drum A through the topinost water tubes B there
will be no liberation of steam from the water which is delivered by the next lower
water tubes B' into the rear headers and which then goes with the steam through
the topmost water tubes B into the drum A, wherein the steam is liberated.
Each inclined water tube B or B thus makes with the oppositely inclined water
tube above or below it and the corresponding portion of the rear or the front
headers a circulation ring in which the water can flow round and round continuously
with liberation of steam at one or both headers, but each of these circulations is
constantly receiving water from a lower circulation (or from the return conduit D)
and delivering water into a higher level circulation (or into the elevated drum A),
the flow in each of these small circulations being influenced and the passage of
water from the lower to the higher level circulations and eventually into the
drum A being determined by the pressure of the water in the return conduit D and
drum A, in which latter the water level is above the highest part of the water tube
system.
The expression of an independent conduit or a steam and water drum in the
claims hereinafter written is not to be understood as excluding from the claim a
boiler with more return conduits than one, or more steam and water drums than
one; nor is the expression of headers and passages to be understood as excluding
the use of a header and a passage.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, 1 declare that what I
claim, is :-
1. The improvement in water tube steam boilers, consisting in forming from the
water tubes and headers lower and higher level circulation rings closed on themselves,
but communicating with each other, and arranging the same to constitute or form
part of the rising leg of an inverted siphon which opens at both ends into the water-
space of an elevated steam- and water-drum, and whose descending leg is constituted
by an independent return conduit; substantially as described.
2. A system of oppositely inclined water tubes, arranged at different levels, and
headers with which said water tubes are connected and through which extend
vertical passages corresponding in section with said tubes, in combination with a
steam- and water-drum elevated above and having its water space connected with
the upper part of said system, and an independent return conduit from the water-
space of said drum to the lower part of said system; substantially as described;
with or without the mud drum interposed between the independent return conduit
and the lower part of said system, as shown.
3. The employment at both ends of the oppositely inclined water tubes, arranged
at different levels, of headers with vertical through passages of corresponding
section, in combination with said water tubes, the steam- and water-drum elevated
above and connected with the system of water tubes and headers, and the independent
return conduit; substantially as described.
4. The employment, in boilers of the new or improved type hereinbefore set
forth, and in combination with the oppositely inclined water tubes, the elevated
steam- and water-drum, and the independent return conduit; of flexible headers

page_text: provided with vertical passages through the same of a section corresponding with
the water tubes and connected with the said water tubes which are oppositely
inclined and are arranged at different levels; substantially as described.
5. The combination with the elevated steam- and water-drum having its lower
part exposed to the heat, of the oppositely inclined water tubes arranged at different
levels under and lengthwise of said drum, the headers having vertical passages.
through them corresponding in section with the water tubes and connected with.
said water tubes to form an intercommunicating ring system of water circulation,.
the direct passage or connection between the upper part of one end of the system
and one end of said drum, and the independent return conduit descending from the-
opposite end of said drum to the lower part of the corresponding end of the said
system; substantially as described..
6. The combination with the oppositely inclined water tubes arranged at different.
levels, the headers with vertical passages through the same, of a section
corresponding with the water tubes, and the independent return conduit, of the-
elevated steam- and water-drum connected at one end directly with the upper part.
of said system of water tubes and headers and with the said return conduit at its
other end and arranged to incline downward towards the point from which the-
independent return conduit descends; substantially as described.
7. The particular constructions and arrangements of water tube steam boilers.
illustrated in Figs. 1-III and in Fig. IV, respectively, of the accompanying.
drawings, and described with reference to such figs. respectively.
Dated this 26th day of June 1894.
W. T. WHITEMAN.