An Improved Water Tube Boiler.
Year: 1899

page_text: Date of Application, 30th Mar., 1899-Accepted, 12th Aug., 1899
COMPLETE SPECIFICATION.
An Improved Water Tube Boiler.
I, JEAN IGERT, of 59, Avenue de la Motte Piquet, Paris, France, 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 relates to a water tube boiler having removable tubes and which
allows of the stoker inserting and removing these tubes in an easy and rapid
manner and which also enables a broken tube to be isolated from the remainder
of the boiler without having to draw the fires.
The accompanying drawing which is given by way of example illustrates one
mode of carrying out this invention. In these drawings, Figure 1 is a rear eleva-
tion of a boiler designed for marine service. Figure 2 is a view partly in side
clevation and partly in vertical section. Figure 3 is a front elevation of the said
boiler. Figure 4 is a partial vertical section of two tubes and a collector to
which they are attached. Figure 5 is a partial horizontal section of one of the
tubes. Figure 6 is a view, partially in side elevation and partly in vertical
section of the boiler when designed to be used as a stationary boiler. Figure 7
is a modification of the tube shown in Figure 5. Figures 8, 9, 10 and 11, illus-
trate different arrangements of tubes situated at the side of the furnace. Figure 12
is a vertical section of a tube provided with a device which enables it to be
isolated in case of breakage, and is provided with an apparatus for indicating
the breakage. Figure 13 is a section on the line X Y of Figure 12. Figure 14 is
a modification of the indicating device shown in Figure 12. Figure 15 is a part
section of a tube provided with an automatic device for isolating the tube in
case of breakage. Figure 16 is a broken view of the vaporizing tubes arranged
on the lateral sides of the furnace.
The cycle of circulation of the water chosen is that of the Field type. The tubes
are arranged in groups in lozenge-fashion and are connected together two rows
at a time to a collector situated at the rear of the boiler and carrying a partition
which divides them into two portions. The group of tubes is inclined towards
the front so as to facilitate the giving off of the steam. A steam and water
drum connects together all the collector elements. This drum or receiver is
extended in the case of stationary boilers (Figure 6) to the front at P, and is
provided with the usual water and pressure gauges. In the marine type (Figures]
and 2) a single tube Q conveys the water to the gauges, because the top of the
boiler must be free to allow of the gases passing off to the chimney. The boiler
is provided with all the ordinary safety apparatus. Figures 4 and 5 show the
details of the fitting in of these tubes. Each of these tubes A is provided at the
forward end on the combustion chamber side, with a hollow hexagonal plug B
in which it is firmly secured permanently by means of a mandril, screw thread, or
other means. At its other end it is simply contracted and turned conically
so as to be jammed into a conical hole formed in the forward wall of the corre-
sponding vertical collector. The inner circulation tube C, C, which is formed
by a very thick tube, is provided at a suitable point with an anchoring device i

page_text: eccen-
formed in one with it, and which abuts against the ends of the vapourising
tube A, (Figure 5). The circulating tube C, C terminates in a screw-threaded
bolt, and by means of the nut D which forms the outer joint of the collector with
the plug E, the necessary tightening is effected for jointing the vapourising
tube A in the inner wall of the collector. The general diameter of the latter may
be greater than that of the base of the end cone, so as to allow of increasing the
heating surface. By this difference of diameter there is produced an
tricity which produces a slight projection against which the anchor W of the
circulating tube can bear. In cases where the vapourising tube is of the same
diameter throughout its length, a point of support for the anchor W can be
obtained by soldering to the inside of the tube an iron ring X (Fig. 7) which is cut
out at the top and also at the bottom to allow of the passage of the anchor.
In the marine type, the circulating tube is in one single piece throughout its
length, because in order to make it enter the vaporising tube it must be passed
in by the forward end from the side of the hexagonal plug. In the stationary
type, the circulating tube will be made in two parts (Figures 4 and 5), a first
part consisting of a thick tube C, and a second part consisting of a thin tube C¹
which is fixed or screwed therein in any manner. The free end of the vapourising
tube may be provided with a movable seating combined with an automatic closing
plug (Fig. 12) consisting of a cone or tube which is maintained by pressure in
its position in the plug 6, and is further secured by means of the screw V
bearing upon the cross piece t. The screw V serves also to make the automatic
joint 6. To remove the tube, the circulating tube may be removed after having
disconnected the two forward and rear. closing plugs. In the marine type the
whole is removed through the front after the plug that closes the middle parti-
tion of the collector has been removed. In the stationary type, the circulating
tube is removed to a certain distance to the rear and after having first made it
execute a rotary motion through 90° for the purpose of disengaging the anchor from
the notches of the vapourising tube, the operation is then the same as above
stated. The small inner tube having been removed, it will be sufficient, for
the purpose of removing the vapourising tube, to draw the same towards the side
of the front of the boiler, each hexagonal plug forming respectively one piece
with its tube. The plug which is immediately above the one which is being
withdrawn will be kept in place by bearing upon the two lateral sides of the
hexagonal faces on the adjacent plugs. To replace the vapourising tube, it will
.he first provided on the side of the cone with an extension of wood. of sufficient
length to serve as a guide for engaging the tube in the collector at the moment
when the workman is about to make the joint at the rear. The insertion of the
circulation tube is effected in the reverse manner of its withdrawal. There then
remains only to tighten the two closing nuts D and J, in order to restore the
generator into working order. In order to close all communication between a
broken tube and the rest of the boiler, there is adapted to the tubes and mainly to
the lower tubes immediately impinged on by the flame in marine boilers, a
device the principal part of which consists of a plug B₁ of cast iron or any
other suitable metal turned conical or cylindrical and provided with perforations
for the passage of steam and water (Figure 12) and adapted to turn in a socket
formed in the collector C, and which is also provided with the requisite. aper-
tures. The plug B is retained by the anchor tube A' which forms at the same
time the joint for the vaporising tube T. The bolt which forms the connection
with the outer wall of the collector, is capable of turning in the tube A The
plug B terminates on the outside at the exterior of the plate of closure P¹ in a
square or hexagonal shaped prism. When breakage of a tube which is provided
with the described device takes place, the fireman, with the aid of a key, turns
the plug through 90 degrees, and in this manner moves it into the closed position
as shown at the right hand of Figure 13. thereby isolating the burst tube from
the collector, and allowing of continuing the stoking of the boiler. In order to
indicate to the fireman which tube has, burst an arrangement shown in Figure 12

page_text: may be employed. This device consists of a thick glass tube M connected in a
suitable manner to the end of the manhole screw V which is bored or made
hollow in order to establish communication between the tube T and the
tube M. The tube M contains mercury and fulfils the office of a compressed air
pressure gauge. A tube similar to the one described is connected to each man-
hole screw V. At the moment of rupture, the pressure in the tube will be
diminished, and the mercury will descend in the tube M and thus indicate the
tube which has burst. A modification of the indicating device above described
consists of a small tube which is employed instead of the pressure gauge tube.
This tube is open at its end (Figure 14). Inside this tube there is arranged a
valve S which is kept upon its seat by the pressure obtaining in the corresponding
vaporising tube, whilst a coiled spring R tends to remove it from its scat. In
case of breakage of the vaporising tube, the pressure drops in said tube, and
the spring R will push the valve down, so that steam will escape from the small
tube and will indicate the burst tube to the fireman.
2°
The closing of the communication between a burst tube and the collector may
be effected automatically. For this purpose a piston 1 is screwed to the end of
the circulating tube A (Figure 15). This piston acts as the equivalent of the
nut D (Fig. 4) in holding the vaporizing tube T in the inner wall of the col-
lector and is recessed on the rear side, and in normal working it abuts against
a closing plug B, which is perforated with a small opening. Between the
piston and the plug B, there is provided a jointing washer. The tube A¹ is
formed with a separating partition R' between the two compartments of the
collector. A coiled spring tends to push the piston P towards the inner parti-
tion of the collector. In case of rupture of the tube, a momentary fall in pressure
ie produced, on the forward side of the partition R¹, and the spring r acts and
pushes the piston P towards the inner wall of the collector. The movement is
aided when the piston has moved through a certain distance by the water under
pressure which comes from the compartment C₁ of the collector. The said
piston moves forward and pushes the tube A¹ through a distance sufficient to
cover the orifices which establish the communication between the collector and
the tubes. In this manner the tube is isolated from the collector. In the boiler
hereinafter described, and more particularly in the marine type, the two lateral
sides of the furnace are provided with vaporising tubes, which operate in the
same manner as the others. A communication box K (Figures 1 and 16) conducts
the water into the collector L, and a tube M ejects the steam and the water.
into the upper receiver 0. These tubes T may be protected by metallic bands N
(Figure 8) connected together by means of bolts, or by square metallic casings
as shown in Figure 9. Finally, these tubes may be surrounded by a cast iron
jacket C, (Figures 10 and 11) preferably of square shape.
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) A water tube boiler comprising circulating tubes of the Field type,
characterised by the arrangement of said tubes so as to allow of the easy inser-
tion and withdrawal from the front of the generator, being anchored at one end
only, and which tubes may have a diameter greater than that of their engaging
portion (thereby allowing of increasing the heating surface) and the expansion
of which is perfectly free, said tubes being capable of being applied to the sides
of the furnace proper, whilst being protected by metal plates connected together
by bolts, or by a hollow casing, or by a cast-iron jacket.
(2) In a water tube boiler as specified in Claim 1. a closing arrangement which
allows of isolating a broken tube from the remainder of the boiler, without having
to draw the fires, characterised by a plug which is capable of being operated
from the rear end of the boiler.
(3) In a water tube boiler as specified in Claim 1, a modification of the closing
device specified in Claim 2, in which said closure is operated automatically,

page_text: characterised by a piston fitted to the end of the circulating, tube, said piston
moving forward in case of rupture of the corresponding tube towards the front
part of the collector and thus closing the communications between the said
collector and the tube.
(4) In a water tube boiler device for indicating a broken tube, each characterised
by a solid glass tube containing mercury, serving as a pressure gauge, and fitted
to the free end of each of the vaporising tubes, so that the breakage of the said
tube by producing a fall of pressure in this tube, causes the mercury to fall in
the pressure gauge, and thus to indicate the rupture to the stoker, the pressure
gauge being capable of being replaced by a tube containing a valve which in a
case of rupture of the corresponding vaporising tube, is pushed by a spring and
allows steam to escape into the atmosphere, and thus call attention to the rupture.
(5) In a water tube boiler of the kind claimed in Claim 1, an engagement of
the plug with self-closing joint for the vaporising tubes at their free ends.
(6) A water tube boiler, constructed substantially as above described and
shown in the accompanying drawings.
Dated this 20th day of Novel 1800
ROBERT E. PHILLIPS, Assoc. M. Inst. C.E., M. I. Mech. E.,
Chartered Patent Agent,
70, Chancery Lane, London, W.C., Associate Agent.