Improvements in Water-tube Steam Boilers.
Year: 1899

page_text: PROVISIONAL
SPECIFICATION.
Improvements in Water-tube Steam Boilers.
I, JOHN ISAAC THORNYCROFT, F.R.S., of the Firm of John I. Thornycroft & Co.,
of Church Wharf, Chiswick, London, W, Marine Engineers and Shipbuilders,
do hereby declare the nature of this invention to be as follows:--
This invention has reference to water-tube steam boilers of what are known
as the "Daring" type (see Thornycroft's Patent No. 17809/90).
Such a boiler, embodying the present improvements, comprises, according to
one arrangement, an upper steam and water vessel, and thres lower water
vessels, between each two of which latter there is a fire-box whose walls are
formed by some of the bent tubes that connect the lower water vessels with the
upper vessel, the lower portion of which latter is connected with the upper por-
tion of the central lower water vessel by means of downflow tubes arranged at
intervals in the length of the boiler, whilst external downflow tubes connect the
lower part of the upper vessel to the upper parts of the side lower vessels. The
smaller bent tubes which at each side connect the central and upper vessels,
enter the latter at each side and are arranged in rows, whereof the two inner
rows (ie. those nearest to the vertical plane of the longitudinal centre of the
boiler) and the two outer rows (i.e. those next to the fire-box) are bent to form
(excepting as to their ends) tube walls which constitute flues wherein the inter-
vening tubes are arranged in rows and the two inner walls serve to protect from
the direct action of the products of combustion the before-mentioned larger down-
flow tubes whereby the upper and central lower vessels are connected, and which
tubes are located between the two inner tube walls. Each of the outer lower
vessels is connected with the upper vessel, also, by several rows of tubes, whereof
the two outer rows and the two inner rows are made to form (excepting as to
the ends of the tubes) walls of a flue within which the remaining tubes are
arranged in rows.
The outer wall of each inner flue and the inner wall of each outer flue meet
at a suitable distance above the fire-grate and the lower portions of the tubes
constituting these respective walls are so arranged as to provide spaces between
the wall-tubes whereby products of combustion can enter the respective flues
up which they flow; the upper portions of the tubes of both walls of each outer
flue and those of the outer wall of the inner flue are arranged to afford spaces
between those portions of the said tubes for the upward flow of the products
of combustion in directions at obtuse angles to the axes of the upper portions of
the tubes, the arrangement being such that the hot gases which have ascended
within the inner flue join, in the upper portion of the outer flue, the hot gases
that have ascended within that fluc, from which these gases pass away to the
chimney through suitable channels formed by and between walls or casings.
the inner one of which is arranged at some distance from the outer surface of
the top portion of the upper vessel, so as to protect that part of the said vessel
from the direct action of the products of combustion.

page_text: Suitable means are or may be provided within the upper vessel for deflecting;
also for separating from the steam, water carried up therewith.
An arrangement for this latter purpose comprises a pipe (hereinafter called
"the inner pipe" and which is or may be closed at one end and at the other end
is in communication with the steam main.
Through an upper side portion of the wall of this pipe there are fine slits or
openings.
Around and secured to the inner pipe, there is an outer pipe or casing (herein-
after called the outer pipe") the arrangement being such as to form an annular
space between the two pipes.
Through the upper portion of the wall of the outer pipe there are slits or
openings. Within the annular space there is a longitudinal partition, which
connects the inner and outer pipes. The arrangement is such that the slits or
openings in the wall of the outer tube are just to one side of this longitudinal
partition, those in the wall of the inner tube just to the other side of the
partition.
In the lower part of the outer tube, there is or are one or more other slits or
openings, and below them there is a longitudinal casing or box, the bottom of
which is inclined downwards towards one end, near which it is provided with
an outlet pipe extending sufficiently downward within the vessel to reach below
the normal water-level, and this outlet pipe is furnished with an automatic non-
return valve arrangement adapted to allow water to escape from the above-
mentioned casing or box but to prevent water entering it from the upper vessel
through the said outlet pipe. Wet steam from the upper vessel passes by the
slits or openings of the outer tube into the annular space between the outer and
inner tubes, travels practically entirely around the annular space, so as therein
to part with any water mixed with the steam, and from the annular space the
steam passes by the slits or openings of the inner tube into that tube, and
thence to the steam main, the water separated from the steam within the annular
space descending to the before-mentioned box or casing and thence by the outlet
pipe into the upper vessel below water-level.
A boiler constructed in other respects according to the present invention, may,
however, be provided with means other than the arrangement above described
for separating the water from the steam.
011
י
1360
Improvements in Water-tube Steam Boilers.
I, JOHN ISAAC THORNYCROFT, F.R.S., of the Firm of John I. Thornycroft & Co.,
of Church Wharf, Chiswick, London, W, Marine Engineers and Shipbuilders,
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 water tube steam boilers of what are known
as the Daring" type (see Thornycroft's Patent No. 17809/90).
Such a boiler is constructed, according to my present invention as I shall now
described with reference to the accompanying illustrative drawings which show
one arrangement of such boiler embodying my present improvements, Fig. 1

page_text: showing a cross section of the boiler on the line of Fig. 2, and Fig. 2
showing the boiler in side elevation.
The boiler here represented by way of example comprises an upper steam
and water vessel and three lower water vessels 2,2", 2b between each two of
which latter there is a fire-box 3 whose walls are formed by some of the bent
tubes 4 and 5 that connect the lower water vessels with the upper vessel 1.
The lower portion of the upper vessel 1 is connected with the upper portion
of the central lower water vessel 2 by means of down flow tubes 6 arranged
at intervals (in one or more rows) in the length of the boiler, whilst external
downflow tubes 7 connect the lower part of the upper vessel 1 to the upper
parts of the side lower vessels 2", 2b, so that each of these vessels and the water
tubes 5 connected thereto will be separately supplied with water direct from
the upper vessel independently of the centre vessel whereby the water circula-
tion and consequently the efficiency of the boiler will be increased, especially
when the boiler is being forced.
The smaller of the bent tubes, riz. 4, which at each side connect the central
lower vessel 2 and the upper vessel 1, enter the latter (or some of them do)
below the normal water-level and at opposite sides of the longitudinal centre
of the boiler. The tubes 4 at each side of the boiler, are arranged in rows,
whereof the two inner rows 4 (i.c., those nearest to the vertical plane of the
longitudinal centre of the boiler) and the two outer rows 4" (i.c., those next
to the fire-box 3) are bent to form (excepting as to their ends) tube walls which
constitute flues 8 wherein the intervening tubes are arranged in rows. The two
inner walls formed by the rows of tubes 4* serve to protect from the direct
action of the products of combustion, the before-mentioned larger downflow
tubes 6 whereby the upper and central lower vessel are connected, and which
tubes are located in a central space or flue S between the two inner tube walls.
Each of the outer lower vessels 2", 2b is connected with the upper vessel 1,
also by several rows of tubes, whereof the two outer rows 5 and the two inner
rows 5 are made to form (excepting as to the ends of the tubes) walls of a
flue 9 within which the remaining tubes 5 are arranged in rows.
The outer wall 4" of each inner flue 8 and the inner wall 5° of each outer
flue 9 meet at a suitable distance above the fire-grate, as at 10. The lower por-
tions of the tubes constituting these respective walls are so arranged as to pro-
vide spaces 11 between the wall-tubes whereby products of combustion can
enter the respective flues 8 and 9 up which they How. The upper portions of
the tubes of both walls of each outer flue 9 and those of the outer wall of cach
inner flue 8 are arranged to afford spaces 12 between those portions of the
said tubes for the upward flow of the products of combustion in directions at.
obtuse angles to the axes of the upper portions of the tubes. The arrangement
is such that the hot gases which have ascended within the inner flues 8 join,
in the upper portions of the outer flues 9, the hot gases that have ascended
within the said flues 9. From this locality the gases pass away to the chim-
ney 13 through suitable channels 14 formed by and between walls or casings 15
and 15. The inner one of these walls or casings, riz. 15, is arranged at some
distance from the outer surface of the top portion of the upper vessel 1 so as
to protect that part of the said vessel from the direct action of the hot products
of combustion. 16 is the ordinary boiler casing.
Suitable means are or may be provided within the upper vessel for deflecting
water and steam; and an arrangement for separating from the steam, water that
has been carried up with the steam. In the example shown plates 1 are pro-
vided for deflecting water and steam from the top of the vessel 1, and plates 15
for deflecting water and steam from the downflow tubes 6. The arrangement
shown in Figs. 1 and 2, and to a larger scale in cross section and longitudinal
section respectively in Figs. 3 and 4, for separating from the steam, water that
has been carried up therewith, comprises a pipe 17 (hereinafter called "the
inner pipe") which is or may be closed at the one end 17" but at the other

page_text: "
end is in communication with the steam main 18. Through an upper side por-
tion of the wall of the said inner pipe 17 there are fine slits or openings 19.
Around and secured to the said inner pipe, there is an outer pipe or casing 20
(hereinafter called the outer pipe") the arrangement being such as to form
an annular space or outer chamber 21 between the two pipes, which space con-
stitutes the chamber in which water is separated from the steam as the latter
flows to the steam main 1S.
Through the upper portion of the wall of the outer pipe there are slits or
openings 22 (see Fig. 3) and within the annular space or chamber 21 there is a
longitudinal partition 23 which connects the inner and outer pipes 17 and 20.
The arrangement is such that the slits or openings 22 in the wall of the outer
pipe 20 are just to one side of the longitudinal partition 23, whilst the slits
or openings 19 in the wall of the inner pipe 17 are just to the other side of the
partition 23. Thus it will be understood that steam entering the chamber 21
by the slits or openings 22 has to pass almost entirely around the exterior of
the inner chamber formed by the pipe 17 before it can enter such inner chamber
by the slits or openings 19; and whilst the steam is thus passing, water that
may have entered the outer chamber with the steam becomes separated there-
from.
In the lower part of the outer tube, there is or are one or more other slits or
openings, as at 24, and below there is a longitudinal casing or box 25, the
bottom of which is inclined downwards towards one end, near which it is pro-
'vided with an outlet pipe 20 extending sufficiently downward within the vessel 1
to reach below the normal water-level. This outlet pipe 26 is furnished with
an automatic non-retiirivalve arrangement adapted to allow water to escape
from the above-mentioned casing or box 25 but to prevent water entering it
from the upper vessel of the boiler through the said outlet pipe 26. Wet steam
from the upper vessel 1 of the boiler passes by the slits or openings 22 of the
outer pipe 20 into the annular space or outer chamber 21 travels therein practi-
cally entirely around the exterior of the inner pipe 17 so as to part with-any
water mixed with the steam whilst the steam is passing through the outer
chamber, and from that chamber the steam passes by the slits or openings 19
into the inner pipe and thence to the steam main 18. The water separated from
the steam within the annular space or outer chamber 21 descends to the before-
mentioned box or casing 25 and thence by the outlet pipe 26 into the upper
vessel 1 of the boiler below water-level therein.
Referring to Fig. 3, 27 is a valve that closes against a seat formed at the
lower end of pipe 26: 28 is a fixed cross pin: 29 is a spring that connects the
valve 27 to the pin 28, thus keeping the valve closed except when water accu-
mulates in the pipe 26 so as to be above the water level in vessel 1 whereupon
the valve is opened by the weight of the water in pipe 26 and allows some of
that water to escape into the vessel 1, after which the valve again closes.
A boiler constructed in other respects according to the present invention, may,
however, be provided with means other than the arrangement above described
for separating the water from the steam and which arrangement forms the sub-
ject matter of another application by me for Letters Patent bearing even date
and numbered 5165.
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 steam boiler of the "Daring type wherein each of the side lower water
vessels is separately connected to the upper steam and water vessel by external
downflow tubes that are independent of the central lower water vessel and its
downflow tubes so that each of such side lower water vessels and the water tubes
. extending therefrom will receive their supply of water direct from the upper
vessel independently of the central lower water vessel, substantially as described.

page_text: "
2. A steam boiler of the Daring type wherein the upper ends of flues
formed by and between some of the tubes in each of the inner and outer groups
of water tubes connecting the upper steam and water vessel to the central and
side lower water vessels are in direct connection with upwardly extending gas
exit channels formed by and between walls or casings the inner of which is
arranged at some distance from the outer surface of the top portion of the upper
steam and water vessel so that such top portion of the said vessel will be pro-
tected from the direct action of the hot gases flowing from the upper ends of the
flues through the said channels to the chimney or uptake, substantially as
described.
3. A steam boiler of the "Daring" type wherein the upper steam and water
vessel, the lower water vessels, the water tubes and downflow tubes connecting
the said vessels, and the gas exit channels leading to the chimney or uptake are
constructed and arranged substantially as herein before described with reference
to the drawings annexed.
4. The improved construction of water tube steam boiler hereinbefore des-
cribed with reference to and shown in the drawings annexed.
تبحت
71
1
P
1000
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.