Improvements in Water Tube Boilers for Generating Steam.
Year: 1897

page_text: Date of Application, 2nd Oct., 1897
Complete Specification Left, 2nd July, 1898-Accepted, 17th Sept., 1898
PROVISIONAL SPECIFICATION.
Improvements in Water Tube Boilers for Generating Steam.
I, JOHN HENRY OWEN, of The Woodlands, Church Lawton, in the County of
Chester, Engineer, do hereby declare the nature of this invention to be as
follows:-
-;
This invention has reference to new or improved construction or arrangements
and combination of parts of steam boilers or generators of the type known as
tubulous or water tube boilers in which the steam is generated in a group or
series of groups of inclined tubes and delivered from thence into a steam drum or
receiver. My present improvements hereafter described relate more particularly
to boilers adapted for use on vessels, although they are also applicable to land
boilers.
It is well known that many of the existing types of tubulous boilers are defective.
1. In respect of the arrangement of their furnace and combustion chambers,
these having in many cases, a grate surface too long and too wide to be easily
managed by the fireman, while at the same time the capacity of the combustion
chamber is either insufficient, or the structure of the combustion chamber is such
that proper mixing of the gases is impossible, and incomplete or imperfect
combustion ensues.
2. The arrangement and disposition of the tubes in many types of water tube
boilers is defective in respect of-facility for repairs, efficiency as heating surface.
3. In most types of water tube boilers the steam drums are of only very moderate
size, and a large portion of their volume is useless as steam space, as a relatively
high water level must be carried to prevent the plates of the drum being injured
by the action of the fire or heated gases.
4. In many types of water tube boilers, the tubes nearest the fire, and in which
naturally steam is generated most rapidly, are so placed that the ascending
currents of water and steam cut off or impede the circulation in the tubes more
remote from the furnace, and thus impair the efficiency of the heating surface to
a marked degree. Further the water supply to the tubes nearest the fire, having
to descend through long and tortuous passages of insufficient area before reaching
the tube, in many cases these tubes are almost constantly filled with steam, and
rupture occurs through the tube burning.
My present improvements are designed to obviate each and all of these defects
and to provide a water tube boiler with water lined combustion chamber forming
integral part of the boiler, large combustion chamber, short grate bars, straight
tubes of ample volume arranged so that they constitute the most effective heating
surface possible, while at the same time they can be readily withdrawn and
replaced, and their outer surfaces kept free from soot deposit, and with the steam
drum entirely isolated from the furnace, and the greater portion of its capacity
being, therefore, available as a steam reservoir, while the heating surface is so
arranged that a constant circulation of the water in the boiler is secured, and the
tubes more remote from the fire do not have the circulation of the water within
impeded or retarded, and at the same time, an ample supply of water to all portions
of the boiler is secured.

page_text: In constructing my improved boiler, I place the steam drum above the level of
the combustion chamber, and to it the rectangular boxes or headers are connected.
Three rows of these headers are vertical or approximately vertical, and they form
the sides and front of the furnace and combustion chamber of the boiler, they are
called respectively furnace sides and front headers. These vertical or furnace
headers are connected at their upper ends by means of cross boxes to the steam
drum, or the front headers can be connected by expanded nipples direct to the
steam drum. They are also connected to a series of horizontal or approximately
horizontal headers into which the tubes are expanded. At their lower ends, these
vertical or furnace headers are connected by means of cross boxes and tubes to the
mud drums from which they draw their water supply. The horizontal or
approximately horizontal headers called respectively upper and lower inclined
headers, are connected together by a series of tubes, which constitute the principal
portion of the heating surface of the boiler. The upper inclined headers also form
the roof of the furnace or combustion chamber, they are connected at one of their
extremities with the furnace front headers (or vertical headers before referred to)
and at one part in their upper surface, with the steam drum or receiver.
.
The lower inclined headers are each connected to the two mud drums of the
boiler from which they draw their water supply. The mud drum or drums of the
boiler which may be one or two in number, are placed at the lowest part of the boiler.
and they are connected to each other and to the furnace headers and cross bars and
to the lower inclined headers, by means of expanded tubes and nipples. At the ends of
the mud drums large downcomers are connected.
These downcomers are external to the boiler casing, and their upper ends are
connected to the steam drum or receiver. The feed water enters the steam drum
and descends through the downcomers to the mud drum, and leaving any sediment
or solid matter which it may contain in the mud drum, it rises through the tubes to
the upper inclined headers, and also through the furnace front and side headers, to
the steam drum, into which it is discharged in the form of steam. The tubes
which connect the upper and lower inclined headers are only slightly inclined to
the vertical, they are, therefore, in the best position for preventing the deposit
of soot on their outer surfaces. The tubes nearest the furnace are also nearest the
steam drum, and thus the steam formed in them escapes freely into the steam
drum, without forcing its way past and driving back streams issuing more slowly
from tubes that are steaming less rapidly. The full value of the heating surface is
thus secured.
In the steam drum a diaphragm or deflector plate may be placed to deflect down-
wards any steam and water carried over from the front headers.
a
The top inclined headers, or three or more of them, may be placed
transversely, or two or more may be placed longitudinally, and
number be placed either transversely at right angles or at any other angle or
inclination to the longitudinal ones, in order to permit of the tubes being
staggered" or so placed as to prevent a straight and unobstructed passage between
them from front to back for the flow of the heated gases and products of com-
bustion.
An additional row of approximately horizontal or slightly inclined longitudinal
headers may be placed midway in the length of the tubes, these being made in two
lengths thus forming two chambers behind the grate space, through which the
heated gases and products of combustion may be passed. It also permits the tubes
which are of short length being withdrawn in a very limited space.
In another arrangement, in addition to the intermediate row of inclined longi-
tudinal headers, the combustion chamber may be lowered, and the heated gases
and products pass between the lower series of tubes, and then between the upper
series, escaping from the boiler at front.
In another modification the tubes are so arranged as to incline to the vertical,
both in the transverse and longitudinal directions of the boiler, and the upper
inclined headers discharge the steam and water into auxiliary side drums, con-

page_text: nected to the main drum at front by suitable connections. These drums are pre-
ferably inclined to the horizontal axis of the main drum. In this arrangement
the furnace is double and capable of being fired from both ends, the grate bars are
arranged in two sets, and the combustion chamber divided by a bridge wall, and
the uptakes are placed at the sides of the boiler.
The headers both horizontal and vertical are formed from steel or iron plates,
and in section they are preferably rectangular. They are pressed to the form best
adapted for the purpose by means of suitable machinery, and they are welded
along the edges most remote from the fire and heated gases by means of suitable
welding machines. The headers may be made of plain square section tubes if
preferred. Opposite each tube and nipple hole, a hand hole is formed, through
which the tube can be withdrawn and replaced. This hand hole is closed by a
cap or door, the joint in each case being internal and the faces are machined and
in each case metal to metal, the pressure in the boiler thus assuring the tightness
of joint. All the tubes and nipples are secured by means of an expander and
no stays are necessary in any part of the boiler.
The steam drum is placed above and outside of the upper inclined headers,
which form the roof of the furnace or combustion chamber. It is, therefore,
quite isolated from the action of the fire, and a very low water level in the steam
drum can be carried.
-
The construction of the combustion chamber admits of a very large grate surface
with very short fire bars, and thus makes easy firing possible. The heated gases
after being generated in the furnace are thoroughly consumed in the combustion
chamber, and passing along among the tubes and below the under surface of the
upper inclined headers are discharged through the uptake.
.
The furnace requires little or no brickwork, being entirely watercased and
externally very little, and only the simplest form of casing and lagging is re-
quired, as the headers and tubes lie so close together at the sides and ends of the
boiler, that very little leakage of air or gases is possible.
11907
WM. P. THOMPSON & Co.,
6, Bank Street, Manchester, Patent Agents.
Improvements in Water Tube Boilers for Generating Steam.
I, JOHN HENRY OWEN, of The Woodlands, Church Lawton, in the County of
Chester, 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 reference to new or improved construction or arrangements
and combination of the parts of steam boilers or generators of the type known
as tubulous or water tube boilers in which the steam is generated in a group or
series of groups of inclined tubes and delivered from thence into a steam drum or
reservoir. My present improvements hereinafter described relate more particu-
larly to boilers adapted for use on vessels although they are also applicable to land
boilers. It is well known that many of the existing types of tubulous marine
boilers are defective,
(1). In regard to the combustion chamber, these being in many cases contracted and
of a form unsuitable for the proper combustion of the furnace gases the result being
serious loss of the heating value of the fuel, high funnel temperatures and flaming
in the uptakes and funnels, besides which the combustion chambers of many

page_text: boilers are formed wholly or partly of brickwork which is altogether unsuitable
for employment on shipboard.
(2) In the arrangement and disposition of the tubes which constitute the princi-
pal portion of the heating surface, in some cases these are bent in such a manner
as to render repair a matter of great difficulty, while in others the tubes although
straight are of such small size and arranged in such a manner that their value
as heating surface is rapidly reduced, first by internal incrustation, and second,
by soot deposit on the outside of the tubes.
(3) In the arrangement of the steam drum or receiver in relation to the furnace,
this being so placed that a high water level and consequent reduction of steam
space is compulsory.
(4) In the matter of water supply to the tubes nearest to the fire where steam
is being formed most rapidly. In many existing types of boilers tube failures have
resulted from inadequate provision being made for a constant water supply to the
tubes which are doing most work.
My present improvements hereinafter described are designed to obviate each
and all of these defects and to construct a water tube boiler.
1st. With an adequate combustion chamber which being waterlined and forming
an integral part of the boiler does away entirely with the necessity for brickwork
while at the same time it can be made of such ample dimensions that complete
combustion of the fuel and furnace gases is secured.
2nd. To construct a water tube boiler in which straight tubes of relatively large
diameter can be used which can be readily withdrawn and replaced and so arranged
that soot cannot adhere to their outer surface to an extent detrimental to their
value as heating surface.
3rd. To construct a water tube boiler in which the steam drum shall be so
thoroughly protected from the direct. action of the fire that a low water level
can be carried with safety and the whole or nearly the whole of the cubic space of
the drum can be utilised as a steam reservoir.
4th. To construct a water tube boiler in which perfect circulation is secured
and in which by the application of external downcomers and connections to the
lower ends of the headers and tubes a constant and ample supply of water is
conveyed to all the tubes.
5th. All handhole joints are metal to metal and all are placed internally thus
preventing all risk of disastrous explosion through failure of handhole joints.
The invention will be fully described with reference to the accompanying
drawings.
Fig. 1. Sectional side elevation of the boiler.
Fig. 2. Front elevation half a section through the combustion chamber and
steam drum or reservoir.
Fig. 3. Sectional side elevation showing a modified construction of the boiler
to permit of the easy withdrawal and renewal of the tubes in a confined space.
Figs. 4 and 5 are plan views of the upper headers showing alternative arrange-
ments of grouping of the tubes.
Figs. 6, 7, 8 and 9, show alternative or modified arrangements of the boiler and
dispositions of the tubes, heating surface and furnace.
Figs. 10, 11, 12 and 13 are details of the construction of the headers into which
the tubes are expanded.
Figs. 14 and 15 are details showing alternative and modified construction of
the headers.
Figs. 16, 17, 18 and 19 are details showing the internal handhole fittings which
are placed opposite each tube end and at the ends of the headers.
Referring to Figs. 1 and 2 the upper inclined headers B are secured to the steam
drum or reservoir A by expanded nipples C, these nipples C are made sufficiently
lang to deliver the steam into the drum above the water level. The headers E
form the front wall of the combustion chamber. These headers are secured at
their lower ends to the cross box G by the nipples & and at their upper ends to

page_text: the upper inclined headers B and to the steam drum A by the nipples e and f
respectively.
The lower front cross box H extends the full width of the furnace and is con-
nected to the upper front cross box G by means of the connecting headers or
boxes I which are secured to the two cross boxes by the nipples and g¹. This
lower cross box H is also connected to the mud drum J, by means of the side
boxes and intermediate tubes Y the end connections to the cross box and mud
drums are made by means of the nipples h and i.
The sides of the combustion chamber are formed by the side headers L which are
connected at their lower ends to the cross boxes F and at their upper ends to the
upper inclined headers B by means of the nipples j and k respectively. The
lower inclined headers K are connected to the mud drum J by means of the
tubes M; the connections between the upper and lower inclined headers B and K
are formed by means of the tubes N. The lower inclined headers K are connected
The tubes P form the con-
to the rear mud drum by means of the nipples 7.
nection between the mud drum J and the rear mud drum O. The large tubes Q
and R are placed outside of the side headers L and the boiler casing X (Fig. 2). These
are connected at their upper and lower ends to the steam drum A and to the front
and rear mud drums J and O respectively.
The fire bars T extend the whole width of the furnace or combustion chamber.
U is the ash pit
The fire doors are placed at the openings marked S on Figure 2.
which is enclosed by the front, side and back plates m and n.
The feed pipe for the boiler is introduced into the steam drum A at any point
that may be found most convenient preferably above the water line, and the steam
stop valves, safety valves, and water gauges may be arranged anywhere along the
upper portion of the steam drum as may be found most convenient. V is the
smoke box which is connected to the uptake and from thence to the funnel.
In the steam drum A diaphragm plates or dash plates p are arranged to deflect
the steam and water carried over from the headers E and B. Hand holes and
fittings are arranged in the various headers and boxes and tubes and are indicated
on the drawings Figure 2 by the letter W. The blow off connections from the
boiler may be taken from either of the mud drums J or (0) or from both if so
desired. Every part of the boiler is composed of wrought iron or mild steel plates.
The tubes and nipples are secured to the various headers and boxes by means
of an expander. The ends of the steam drum A and the mud drum J are formed
of dished steel plates and the whole of the boiler is constructed to avoid the use of
stays.
Referring to Figs. 1 and 2, when under steam the boiler is worked as follows:-
the feed water enters the drum through a check feed valve and internal feed pipe
in the usual manner and passing on descends through the down comers Q and R
to the mud drums J and O from thence the water as it is heated and converted into
steam rises through the tubes N into the upper inclined headers B and through
the furnace sides and headers L and E passing into the steam drum through the
nipples c and f. The circulation it will be observed is continuous.
By the arrangement of the side and front headers L and E which form the walls
of the furnace and which are, therefore, exposed to the most intense heat the steam
which is raised in these parts of the boiler and also in those tubes N which are
near the furnace more rapidly than in the parts more remote escapes freely into
the steam drum. The tubes N which are nearest the fire and the walls of the
furnace being so arranged, the steam formed in them rising through the upper
inclined headers B into the steam drum induces circulation in the portion of the
upper inclined headers B farthest from the combustion chamber and tends to
promote instead of retarding circulation in such of the tubes N as are farthest from
the furnace. In thus arranging the heating surface of my boiler it will be
observed that I avoid a defect frequently present in other types of water tube boilers
where the tubes nearest the fire are placed below and farther from the steam drum
or reservoir than others which do less work, when such boilers are forced the rapid

page_text: circulation in the lower tubes cuts off or impedes the circulation in the upper tubes
producing an intermittent movement of the steam bubbles in these upper tubes
and seriously impairing the efficiency of the heating surface.
It will be further observed by reference to Figures 1 and 2, that each of the
lower headers K receive an ample supply of water from the mud drums J and O
through the tubes M and the nipples. The tubes N in each section are therefore
kept full and risk of burning through inadequate water supply is therefore avoided.
In this respect my boiler possesses a direct advantage over those other types of
water tube boilers where the water has to descend from the drum through con-
tracted headers with the result that when the boiler is forced the lower tubes do not
receive a sufficient supply of water and being filled with steam frequently give
way through burning. It will further be observed by reference to Figure 1 that
the downcomers Q and R which are of very large area are placed outside of the
boiler casing X and away from contact with the heated gases. A constant down-
ward flow of water to the lower parts of the boiler through the mud drums J and O
is thus secured and the circulation which is induced by the heated water and steam
rising in the tubes N and headers L and E to the steam drum is promoted by
the unimpeded descent of the colder stream. Any sediment or solid matter which
may be contained in the feed water will naturally fall to the lowest level in the
mud drums J and O and may be blown off through the blow off cocks placed there
for that purpose.
The fire bars T are short and therefore well adapted for forcing the boiler as the
fireman can more easily manage a short furnace than a long one. The combustion
chamber is of very large proportion and offers every advantage for the proper mixing
of the gases and for complete.combustion before coming in contact with the heating
surfaces. The gases of the heated products of combustion pass through among
the tubes N (which are arranged as indicated in Fig. 4) to the uptake V. If it be
preferred or if for any reason it is desired to baffle or in some degree obstruct the
too rapid passage of the gases to the uptake V several rows of tubes may be
arranged as shown in Fig. 5. This arrangement is secured by several of the
upper inclined headers B being arranged transversely as shown. The tubes which
are placed in these transverse headers are arranged so that they come opposite the
openings or lanes between the tubes of the other headers and therefore present a
considerable obstacle to the rapid flow of the gases. The number and position of
these transverse headers may be altered at will. Their connection to the longitud-
inal headers is made as elsewhere in the boiler by means of nipples through which
continuous circulation of the water and steam to the steam drum A is effected.
As all the tubes N are arranged, approximately vertically, the soot cannot readily
adhere to their outer surfaces and any that falls to the lower inclined headers K
can be easily brushed off through side doors in the casing X or blown off by means
of a steam jet introduced through the fire doors S or from the rear from the uptake
or smoke box V.
By reference to Figs. 10, 11, 12, and 13, it will be observed that the inclined
headers B and K and the furnace side and front tubes E and L and the
connecting boxes and mud drums G, H, K, O) are composed of boxes made from
steel or iron plates preferably of rectangular section and welded along the
flange bb. The headers are stamped to the required form and are welded by
suitable machinery. Handholes Ware formed opposite each tube end through
which tubes or nipples may be withdrawn or replaced. The inner edge of hand
hole is faced at a and the orifice is closed by means of the clamp or covers shown
in Figs. 16 and 17. These clamps are introduced into the interior of the headers
through the oval handholes r shown in Figs. 18 and 19 or in the case of the front
or side furnace headers through the large nipples C at the end. (Fig. 1). By these
means it will be observed that all joints are metallic (that is, they are made with-
out any packing material), are internal and there is no risk of serious accident
through the failure of a hand hole bolt as might occur if the joints were external..
In Figs. 10 and 11 the face a for clamp is shown depressed or embossed, in

page_text: Figs. 12 and 13 it is shown plain, that is, the surface of the metal which forms the
hickness of the headers is faced up sufficiently to make a perfectly true seating.
The face of the clamp is also machined to bear upon the machined face of the
eader. The tube holes t are bored opposite to and perfectly concentric with the
andholes W so that any tube or nipple can be withdrawn and replaced with ease.
Figures 14 and 15 show an alternative construction of the headers in which if
t is preferred or the circumstances of the case demand it rivetted joints can be
ased. In this case the header is made in two pieces the plates being first flanged
by suitable machinery or rolled to section as channel iron or steel and rivetted
ogether along the edges b. In each case whether the headers are made as shown
In Figs. 10, 11, 12, 13, 14 or 15 the ends are closed by end pieces q welded in.
These end pieces are either bored out for an oval handhole having an internal seat
as shown in Fig. 11 a or bored for a nipple connection as shown at Figs. 10
and 12, in either case the opening being sufficiently large to allow of the clamp
(previously referred to Figs. 16 and 17) being introduced.
By referring to Figures 4 and 5 it will be observed that when the headers are
laid together they form a comparatively tight joint. In the case of the combustion
chamber this does away with the necessity for any brickwork. Any slight open-
ings can be filled up with asbestos yarn or fibre, the outer surfaces of the headers
can be lagged with some non-conducting material, the flanges bb, Figs. 10 to 15,
forming convenient ridges for retaining such material and the whole can be kept
in place by a light sheet iron or planished steel plate. All leakage of air into the
combustion chamber is thus prevented.
tion as
Referring again to Fig. 1 it should be observed that in every instance the
edges 6 of the headers B, K, E, and F as detailed in Figs. 10 and 12 are turned
away from the fire and the heated gases, the welded portion being thus not
exposed to the high temperatures. The outside surfaces of the upper and lower
inclined headers B and K Figs. 1 and 2 are covered with non-conducting composi-
previously referred to and are also provided with light lagging plates or
covers which can be lifted off when any tubes require to be withdrawn or replaced.
Fig. 3 is a sectional side view and shows a modified arrangement of Fig. 1, in
this case the only difference is that an additional row of inclined headers Z are
placed midway in the length of the tubes N which are in this instance made in
two lengths. The upper rows of these tubes have their lower ends expanded into
the upper surface of the headers % and the lower rows their upper ends expanded
into the lower surface of the same header. This construction of boiler permits of
the tubes N which are in short lengths being withdrawn in a very limited space,
the height required for withdrawal not exceeding that occupied by the steam
drum A. Figs. 6 and 7 are sectional side elevations showing alternative arrange-
ments of the boiler in which the tubes N are arranged in two lengths as in Fig. 3
but in these cases the combustion chamber is lowered and the waste gases and
heated products pass first along the lower section of the tubes N and return to the
front of the boiler escaping by the uptake V as indicated. When the boiler is
constructed after this fashion, the rear portion of the boiler is enclosed with a
casing X similar to that used for the sides of the boiler and indicated in Fig. 1.
Figs. 8 and 9 are respectively a sectional side and end view of the boiler con-
structed somewhat differently. In this case the downcomers R are dispensed with
and the large downcomers Q are placed in front of the boiler to save side space.
These downcomers are connected to the mud drum J by means of large connecting
pipes Q'; in this construction it will be observed that the steam drum A is brought
forward in front of the headers E and is connected to them at the rear by means of
the nipples cf.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is:
-
1: A water tube boiler having the several parts constructed and arranged in

page_text: combination, substantially as described and shown with reference to either of the
figs. of the drawings.
2. A water tube boiler constructed with a series of rectangular boxes or headers
forming the top, sides, front and bottom of the combustion chamber, water tubes
connecting the top and bottom headers, a steam drum or receiver placed out of
direct contact with the heated gases of combustion and down comers of large
sectional area also placed out of contact with the heated gases which connect the
steam drum with mud drums placed at a lower level than the headers substantially
as and for the purpose described.
3. A water tube boiler constructed with a number or series of rectangular steel or
iron boxes of channel section horizontally inclined to form the roof of the furnace
or combustion chamber and connected at their higher ends to a steam drum sub-
stantially as described and shown.
4. A water tube boiler constructed with a number or series of rectangular steel
or iron boxes vertically inclined to form the front of the furnace or combustion
chamber connected at the upper ends to the steam drum and at the lower ends to
transverse horizontal boxes or headers from which they draw their water supply,
substantially as described and shown.
5. A water tube boiler constructed with a number or series of rectangular steel
or iron boxes vertically inclined to form the side walls of the furnace or combustion
chamber connected at their upper ends to longitudinal horizontally inclined headers
connected to the steam drum, at their lower ends to longitudinal horizontal inclined
headers which draw their water supply from the mud drums, substantially as
described and shown.
6. A water tube boiler constructed with a number or series of rectangular steel
or iron boxes horizontally inclined placed behind the combustion chamber con-
nected at their lower sides by rows of tubes to the mud drum from which they draw
their water supply and at their upper sides by a series of tubes to the rectangular
boxes which form the roof of the furnace, substantially as described and shown.
7. In a water tube boiler the combination and arrangement of mud drums or
collectors connected to the steam drum by means of large down comers placed
externally to the furnace and to the lower horizontally inclined boxes at the front
end of the furnace or combustion chamber substantially as described and shown
with reference to Figures 1 to 3, and 6 to 9 of the drawings.
8. In a water tube boiler the construction and arrangement of straight vertically
inclined tubes connected at their lower ends to rectangular horizontally inclined
boxes which draw their water supply from the mud drum and at the upper ends to
horizontally inclined boxes which form the roof of the furnace, substantially as
described and shown.
9. In a water tube boiler the arrangement of the steam drum in relation to the
heating surfaces by which the drum may be completely isolated from the direct
action of the heated gases or products of combustion substantially as described and
shown with reference to either of the figs of the drawings.
10. In a water tube boiler the combination and arrangement of a steam drum
or reservoir placed above and in front of the straight vertically inclined tubes to
which it is connected by horizontally inclined boxes, and connected by large down
comers placed outside the furnace to the mud drums placed at the bottom substan-
tially as described and shown with reference to Figs. 6 and 7 of the drawings.
7
1000
Jatet
en AST Su
ne to
1030
WM. P. THOMPSON & Co.,
Manchester, Liverpool & London, Patent Agents.