Improvements in Steam Generators.
Year: 1893

page_text: Date of Application, 30th May, 1893
Complete Specification Left, 28th Feb., 1894-Accepted, 19th May, 1894
Improvements in Steam Generators.
I, JOHN SAMPSON, of 40 Acre Lane, Brixton in the County of London,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention has reference to a construction of steam generator of tubulous
type in which the crown or upper part of the furnace and furnace flue is composed
of water tubes (hereinafter called crown tubes) arranged close together and each
connected with one or more upper longitudinal steam and water vessels by uptake
tubes arranged to traverse a combustion chamber or chambers that is or are formed
by and between the said crown tubes, the longitudinal vessel or vessels, and a
suitable wall or casing, and is or are in connection with the furnace flue at the rear
end thereof, the said crown tubes and longitudinal vessel or vessels being also in
communication with each other by downtake tubes located outside the said
combustion chamber or chambers.
To provide for ready expansion and contraction of the various parts the uptake,
downtake and crown tubes may advantageously be suspended from the longitudinal
steam and water vessel or vessels which are then suitably supported by pillars
or otherwise as may be found convenient. In connection with the longitudinal
steam and water vessel or vessels may be provided one or more supplementary
steam vessels.
The casing at the ends of the steam generator is provided with suitable doors for
gaining ready access to the combustion chamber or chambers for the purpose of
cleaning the tubes therein, for the removal of soot and ashes therefrom, and for the
removal of ashes from behind the fire bridge of the furnace.
The longitudinal steam and water vessel, or each of them when more than one
is used, is provided with one or more suitably arranged man-holes to facilitate
examination, cleaning and repair of such vessel. Also the crown tubes are each
provided with removable plugs and with blow-off valves to facilitate their being
cleaned. The outer ends of the crown tubes may be connected by a common pipe
fitted with a blow-off valve and whereby the water in the various connected tubes
and vessel or vessels can be maintained approximately level.
To admit of the uptake and downtake tubes being readily fixed in place they
may be screwed into the upper side of the crown tubes which may be recessed
around each tube to form a stuffing box for packing which may be compressed by a
ring screwed upon the corresponding tube and formed with a notch or other means
by which it can be easily rotated. The upper ends of the said tubes may be left
plain and be secured within screw-threaded holes in the tube plate forming the
lower side of the steam and water vessel or vessels by simply expanding them into
the screw-threaded holes. The said tubes and vessels may however be connected
together in any other suitable manner.
A longitudinally arranged deflecting plate may be arranged between the upper
ends of the down take tubes and the upper ends of the uptake tubes which latter
may be arranged to extend upward within the steam and water vessel to a greater
extent than the downtake tubes and may if found desirable be carried up into the
steam space of such vessel. Such uptake tubes may also be provided at their
upper ends with baffle plates or caps to facilitate the separation of the water from
the steam passing through such tubes. The longitudinal steam and water vessel
or vessels may be each provided in the steam space with a suitable baffle plate or
plates with the object of preventing water entering the steam pipe by which the
steam is led to an engine.

page_text: As will be obvious steam generators according to this invention can be variously
modified.
In one arrangement the crown tubes, longitudinal vessels and uptake tubes are
arranged to form, in conjunction with suitable walls, two separate combustion
chambers that are each in communication with the furnace flue at the rear and
with a smoke box at the front of the generator, and each of which can be shut off
from the furnace flue when desired. Each of the longitudinal vessels is
approximately of semi-circular form in cross-section, the lower side, forming the
tube-plate, being flat. The uptake and downtake tubes are straight and arranged
vertically and the crown tubes are arranged in two series inclined to each other
and made to form a crown that gradually descends from the fire bridge to the rear
end of the furnace flue.
In a modified construction, the uptake and downtake tubes are inclined to the
vertical and the upper tube plates to which they are connected are each inclined to
the horizontal so that the greatest depth of water in each steam and water vessel
will be above the downtake tubes.
Steam generators constructed as described can be easily and cheaply constructed,
transported, cleaned and repaired; they provide a large and effective heating
surface giving a high evaporative efficiency; and they can be constructed in a
compact form, of comparatively small weight, and so as to occupy much less space
in proportion to heating surface than steam generators of the locomotive type as
usually constructed.
Dated this 30th day of May 1893.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Steam Generators.
I, JOHN SAMPSON, of 40 Acre Lane, Brixton, in the County of London,
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 a construction of steam generator of tubulous
type in which the crown or upper part of the furnace and furnace flue is composed
of water tubes (hereinafter called crown tubes) arranged close together and each
connected with one or more upper longitudinal steam and water vessels by uptake
tubes arranged to traverse a combustion chamber or chambers that is or are formed
by and between the said crown tubes, the longitudinal vessel or vessels, and a
suitable wall or casing, and is or are in connection with the furnace flue at the rear
end thereof, the said crown tubes and longitudinal vessel or vessels being also in
communication with each other by downtake tubes located outside the said
combustion chamber or chambers.
In the accompanying drawings,
Fig. 1 is a cross-section on the line A B of Fig. 2; and
Fig. 2 is a longitudinal section on the line C D of Fig. 1, but to a smaller scale,
showing one construction of steam generator according to this invention, arranged
within a navigable vessel, such as a torpedo boat, which is also shown in section.
Figs. 3 and 4 are detail views hereinafter referred to.
1, 1 are water tubes arranged in two series at opposite sides of a longitudinal
plane passing through the centre of the generator and slightly inclined to each other
as shown. These tubes, herein called crown tubes, which are or may be supported
at their inner ends upon a central longitudinal girder or bearer 2, and at their outer
ends upon the side walls 3 of the furnace 4 and furnace flue 4*, are arranged close

page_text: together so as to form a doubly inclined tubulous roof or crown to the said furnace
and furnace flue. 5, 5 are two upper longitudinal steam and water vessels
corresponding to the two series of crown tubes with which they are respectively
connected by two series of uptake tubes, 6, 6ª and downtake tubes 7, 7, there being
several uptake tubes, twelve in the example shown, and one downtake tube, to each
crown tube. 8, 8* are pairs of side walls of refractory material, that form in
conjunction with the two series of crown tubes 1, 1", and the longitudinal steam and
water vessels 5, 5ª two independent combustion chambers or flues 9, 9ª (herein
called combustion chambers), that are traversed by the two series of uptake
tubes 6, 6 respectively, the downtake tubes, 7, 7ª being external to the said
chambers. The side walls 8, 8ª may be each formed of sheet metal lined with fire
clay, or of two thicknesses of sheet metal (Fig. 4) with an intermediate layer of
refractory material, such as asbestos, that is also a bad conductor of heat, the said
Each of the com-
walls being firmly secured in place in any convenient manner.
bustion chambers 9, 9" is in communication with the furnace flue + at the rear by
an opening 10, and with a smoke box 11 at the front, the rear ends of the said
chamber being closed by a casing 12 that also serves to form the rear end wall of
the furnace flue 4". This end wall, as well as the sides 3 of the furnace 4, and the
sides and bottom of the furnace flue, are protected by a lining of refractory
material 3*. By the construction described it will be seen that the crown tubes
will afford a large and effective heating surface to the flame, hot gases and radiant
heat proceeding from the fire on the fire grate 4*, and that the flame and hot gases
escaping from the furnace flue into the combustion chambers 9, 9* will be compelled
to traverse these chambers in a direction at right angles to the uptake tubes 6, 6*
therein whereby the maximum heating effect will be obtained. Each opening 10 is
controlled by a damper 13, as also is each uptake 11, so that either of the com-
bustion chambers can be cut off from the furnace flue at will, when it is desired to
clean such chamber, or the tubes therein, for which purpose the casing 12 and the
to the
sinoke boxes 11 are provided with suitable doors for gaining access
chambers. The furnace flue may also be provided with a door for removal of ashes
from behind the fire bridge 14 of the furnace. The steam and water vessels 5, 5*
are connected together by a distance piece 5° which serves to hold them in place,
and they may be supported above the crown tubes, when these are carried by the
sides and ends of the furnace and furnace flue, either by the uptake and downtake
tubes alone, or in conjunction with suitable external stays, such as 5 which are
arranged to connect each vessel 5, 5" with the ends of the corresponding set of
crown tubes in any suitable manner. Each of the vessels 5, 5* is provided with one
or more suitably arranged man-holes to facilitate examination cleaning and repair
of such vessel and also the fixing in position and cleaning of the uptake and down-
take tubes, and is preferably of approximately semi-circular form in cross section,
as shown, its lower side 5* which forms a tube plate for the upper ends of uptake
and downtake tubes, being flat and preferably strengthened by roof stays 13
arranged at suitable distances apart. In the example shown, the tube plates 5* are
each inclined to the horizontal and towards each other so that the greatest depth of
water in each steam and water vessel 5, 5ª will be above the downtake tubes 7, 7",
and by arranging each of the said tube plates parallel with the corresponding
series of crown tubes, as shown, all the uptake and downtake tubes can be made of
the same length, thereby facilitating the construction and repair of the stea n
generator. Each steam and water vessel may with advantage be provided with a
longitudinal deflecting plate 15 fixed to the tube plate 5* between the upper ends of
the downtake tubes and the upper ends of the uptake tubes for the purpose of
directing the ascending and descending currents of water and avoiding a short
circuit for the water between the downtake tubes and the uptake tubes in proxim ty
thereto. Each of sad vessels may also with advantage be provided with a longi-
tudinal baffle plate 16 arranged above the upper ends of the uptake tubes and
formed with holes 16" below which are fixed supplementary baffle plates 16, the
arrangement being such as to prevent water passing with the steam through the

page_text: holes 16 into the steam space above, whence such steam is led away to an engine by
a suitable steam pipe.
The crown tubes 1, 1* which may for example be about say 3 inches in outside
diameter and of mild steel, may be of circular form in cross section as shown, or of
other form, such as square or rectangular. Each of them is provided at its outer
end with a removable plug 17, and it may be also with a blow-off valve, to facilitate
its being cleaned. The uptake and downtake tubes, may also be of mild steel, and
say for example of about 1 inches in outside diameter. The dimensions of the
various tubes however, can obviously be varied to suit requirement. Each uptake
tube is preferably fitted with a spiral metal retarder 6*, as shown to a larger scale
in Fig. 3, to prevent water flowing through it too rapidly, such retarder being
arranged to bear against the interior of the tube within which it is fitted so that it
may also conduct heat from such tube and provide additional heating surface.
In order that the water may be maintained approximately level in the various
connected tubes and vessels, notwithstanding extreme pitching of the boat to which
the steam generator is applied, the outer ends of the crown tubes may advan-
tageously be connected by means of detachable elbows 18 with a pipe 19,
hereinafter called for distinction the levelling pipe, which is common to all the
crown tubes, and is preferably connected with the front and rear ends of each
steam and water vessel 5, 5ª by downtake tubes 20. This levelling pipe, which
extends around the sides and rear end of the steam generator, is preferably inclined
downwardly towards the front of the generator as shown, and its lower free ends
each provided with a sediment chamber 21 and blow-off valve 22. Into this
levelling pipe the feed water may conveniently be introduced.
To admit of the uptake and downtake tubes being readily fixed in place, they
may, as shown in Fig. 4, be screwed into the upper side of the crown tubes 1, 1
which may be recessed around each tube to form a stuffing box 23 for packing,
which may be compressed by a ring 24 screwed upon the corresponding tube and
formed with a notch 24*, or be otherwise formed, so that it can be easily rotated
by a suitable tool. The upper ends of the said tubes may be left plain and be
secured within screw-threaded holes in the tube plate 5* of the corresponding
steam and water vessel 5, or 5* by simply expanding them into the screw-threaded
holes. The said tubes and vessels may however be connected together in any
other suitable manner.
As will be obvious steam generators according to this invention can be constructed
in different forms and be otherwise variously modified. Thus instead of inclining
the uptake and downtake tubes to the vertical and the tube plates 5* to the
horizontal, as in the arrangement herein before described, the said tubes may in
some cases, as in stationary steam generators, be arranged vertically and the tube
plates horizontally, as in the modified construction shown partly in cross section
and partly in front elevation in Fig. 5. Also instead of having one furnace and
furnace flue common to two or more independent steam generating sections of the
boiler as herein before described, there may be an independent furnace and furnace
flue for each steam generating section; or the generator may consist of a single
furnace and furnace flue with a single steam generating section. Again to provide
for ready expansion and contraction of the various parts, the uptake, downtake and
crown tubes may be suspended from the longitudinal steam and water vessel or
vessels which is or are then supported by pillars or other suitable means as may be
found convenient. Also there may be provided in connection with the longitudinal
steam and water vessels, a supplementary steam vessel 25 as indicated in dotted
lines in Fig. 5. Furthermore there may be only one series of crown tubes, either
straight or bent, which may be connected with a single steam and water vessel,
such as 5, or 5, or with two or more of such vessels, the construction in other
respects being similar to that hereinbefore described.
Steam generators constructed as described possess many important practical
advantages. They can be easily and cheaply constructed, transported, cleaned and
repaired; they provide a large and effective heating surface giving a high

page_text: evaporative efficiency and providing for a natural and effective circulation of the
water; and they can be constructed in a compact form, of comparatively small
weight, and so as to occupy much less space in proportion to heating surface than
steam generators of the locomotive type as usually constructed.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:
1. A steam generator of tubulous type in which the crown or upper part of the
furnace and furnace flue is composed of water tubes such as 1, 1ª arranged close
together and each connected with one or more upper longitudinal steam and water
vessels by uptake tubes arranged to traverse a combustion chamber or chambers
that is or are formed by and between the said crown tubes the steam and water
vessel or vessels and a suitable wall or casing, and is or are in connection with the
furnace flue and with a chimney or uptake, the said water or crown tubes and the
water and steam vessel or vessels being also in communication with each other by
downtake tubes, substantially as hereinabove described.
2. The combination with a steam generator of the kind referred to in the
preceding claim, of a levelling pipe such as 19, connected with and common to the
various crown tubes substantially as herein described for the purpose specified.
3. My improved steam generators constructed substantially as herein described
and shown in Figs. 1 and 2, and in Fig. 5 of the drawings annexed, or modified as
set forth.