An Improved Steam Generator.
Year: 1895

page_text: An Improved Steam Generator.
I SAMUEL HODGSON LLOYD 4 High Street, Bloomsbury London, W.C.
Mechanical Engineer do hereby declare the nature of this invention to be as
follows:-
My improved steam generator consists of a number of inclined outer tubes
containing inner tubes with an annular space between connected at each end to
headers these latter leading to separate steam and water chambers, a pressure
equalizing pipe to connect the steam and water chambers, a drain pipe is provided
to carry away any water which may rise into the steam chamber to the water
chamber the usual steam fittings such as gauge glasses safety valve pressure gauges
and the like are cimployed.
The water chamber is arranged to be lower than the steam chamber and higher
than the highest inclined tube. Both steam and water chambers are cylindrical
parallel to each other and horizontal. Each header has in both steam and water
chambers a valve coated with lead or other soft metal above it at its junction with
the chamber with a spindle running through the upper part of the chamber fitted
with a packing gland the object of the valves being. to enable a section of tubes
being cut out or closed in case of damage while under steam or otherwise. The
inclined outer tubes containing the inner tubes are attached to the inner faces of
the headers the inner tubes being attached to the outer faces of the headers with
an annular space between the tubes for water.
A fire grate is provided to fall upon the furnace floor by a parallel motion to
enable the fire to be taken from immediate contact with the tubes when steam is not
required or steam pressure needs reducing with dampers working in unison with the
grate arranged to enable the fire to be directed through the furnace and inner
tubes into funnel uptake as may be required or easily controlling the generation of
steam by directing the fire direct to uptake without passing through furnace or
tubes.
The water falls from water chamber into headers attached thereto and is then
distributed to the annular spaces between the outer and inner tubes where it is
converted into steam and the steam thus formed rises through headers attached to
steam chamber into steam chamber. The feed water is taken in the water chamber.
This steam generator is equally adapted and is intended for both land and
marine purposes.
I claim
1. The arrangement of inner and outer tubes for generating steam.
2. The combination of a falling grate and controllable dampers.
3. The arrangement of valves above headers for the purpose of cutting out any
damaged section of tubes.
A
"The voverol dosion and arrangement of the generator

page_text: I, SAMUEL HODGSON LLOYD, of 4 High Street, Bloomsbury, Engineer in the
County of London, 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 an improved construction of steam generator as
I shall now describe with reference to the accompanying drawings wherein
Fig. 1 is a part front elevation and Fig. 2. a cross section of such a steam
generator.
It comprises a series of inclined outer tubes 1 secured at their ends in any.
suitable manner, as by expanding, to the inner walls of headers 2 and 3 aud
provided internally with fire tubes 4 the ends of which are similarly secured to the
outer walls of the said headers so as to form with the tubes 1 annular water
passages that are in free communication at each end with the headers and whereby
the water in the said annular spaces will be heated both from the outside and from
the inside. The headers are connected to the lower sides of two separate
cylindrical steam and water vessels or drums 5 and 6 that are arranged parallel to
each other and are connected at the top by a pressure equalizing pipe 7 and at a
lower level by a drain pipe 8 which serves to lead any water entering the steam
vessel 5 from the headers 2 to the water vessel 6 which is arranged at a lower level
than the steam vessel 5 but above the highest of the outer tubes 1 so that there
will always be a sufficient head of water to fill these tubes. By using separate
steam and water vessels 5 and 6 connected by a drain pipe as described, the steam
passing into the steam vessel from the headers 2 has not to pass through a large
body of water so that it will be delivered into the said vessel in a much drier
condition than would otherwise be the case. 9 is a roof of refractory material
arranged above the tubes.
The tubes and headers are arranged, as shown, so as to form independent sections
As
each comprising a vertical group of tubes 1 and 4 and two headers 2 and 3.
will be obvious the number and dimensions of the section, and the number,
arrangement and dimensions of the tubes in each section can be varied to suit
requirement.
To enable any section of tubes with their corresponding headers to be shut off
from the steam and water vessels, in the event of damage to or leakage of the
tubes or headers and thus to enable the section to be put out of use without having
to draw the fire, the communication between each header and the steam and water
vessels is controlled by a valve 10 arranged above the section and within the vessel
and coated with lead or other soft metal so that it can be caused to effectually close
the communication between the header and vessel when depressed. Each of the
valves 10 is carried by a spindle 10 which passes through a fixed guide 11 and
stuffing box 12 to the exterior of the vessel where it is provided with a hand-
wheel 10° by which it can be conveniently operated.
The combined sections of tubes and headers are arranged within a casing 13
above a firegrate 14 and a firebridge 15 which extends up to the bottom row of
tubes 1. Dampers 17 and 18 arranged respectively at the front and rear ends of
the casing 13 serve to control the passage of flame and hot gases direct from the
combustion chamber 19 to smoke box 20 and chimney or uptake 21 and from
the combustion chamber to the rear ends of the fire tubes 4. To enable the action
of the fire on the grate 14 to be reduced when desired, as when steam is not
required or when the steam pressure or rate of working of the boiler needs

page_text: reducing, the fire bars are connected at their ends to motion bars comprising
lever arins 22 and 23 fixed upon horizontal shafts 22 and 23* respectively and
capable of being moved by a handle on shaft 22", from the position shown in full
lines in Fig. 2 to that shown in dotted lines, so that the fire-grate can, when desired,
be caused to fall upon the floor of the ash pit 24 as indicated in dotted lines.
The dampers 17 and 18 in this case are preferably connected to the shafts 22, 23
so as to be operated in unison with the fire grate. For this purpose the shaft 17ª
of damper 17 may be connected to the shaft 22 by lever arms 17b and 22b on the
respective shafts and a link 25, the shaft 18ª of damper 18 being similarly connected
by lever arms 18', 23' and link 26 with the shaft 23. By this means when the
fire grate is in its normal position, the damper 17 will be closed and the damper 18
open, the flame and hot gases passing in the direction of the arrows amongst the
tubes 1 and through the tubes 4 to the smoke box 20 and thence to the chimney
or uptake 21. If however the firegrate be lowered the damper 17 will be
simultaneously opened and the damper 18 closed and the flame and hot gases will
pass direct to the smoke box and chimney, the tubes 1 and 4 being then heated to
a comparatively small extent. In this way the rate of working the boiler can be
varied to suit requirement.
In the working of the boiler, water descends from the water vessel 6 to the
headers 3 and thence to the annular passages between the concentric tubes 1 and 4,
the steam generated in these passages, together with that generated in the headers 2
passing upward through the latter headers to the steam vessel 5, water carried up
by the steam into the said vessel flowing back by the pipe 8 to the water vessel 6.
Steam generated in the headers 3 will pass to the upper part of the water vessel 6
when it can pass to the steam vessel 5 by the pipe 7. To obviate any liability of
sediment collecting in the lower ends of the headers 2 and 3, the lower ends of each
pair of headers may be connected by a water circulating pipe. Or the lower ends
of the headers may be provided with removable bottoms for clearing out any
deposit from time to time. The feed water is supplied to the water vessel 6. The
steam vessel is provided with any convenient arrangement of steam delivery pipe
(not shown) and, it may be, with a baffling arrangement to prevent as far as possible
any water being carried off with the steam drawn from the said vessel. The steam
generator is also provided with all the usual fittings.
A steam generator constructed as described and which may be used as a land
boiler or marine boiler, possesses many important practical advantages. It
possesses a very large heating surface in proportion to the amount of water in
contact therewith, thereby enabling an exceedingly rapid generation of steam to be
effected, whilst enabling a suitable quantity of water to be carried in the water
vessel.
It is specially adapted for use on board ship as any portion of it can be passed
through an opening 4 ft. square and the generator can be built together in position,
all parts being readily accessible.
If a tube bursts or splits the whole section to which it is connected can be
readily shut off without drawing the fires. All the tubes are straight, and there
are no stay tubes required, and comparatively little rivetting. The weight of the
steam generator compares very favourably with other types of steam generator,
whilst it is cheap in construction and requires no special tools either for manufacture
or repair. The steam can be generated in a very few minutes after the fires are
lighted so that when used for marine purposes, banked fires are not necessary. No
special skill in firing is required and no more attention than is required for any
other type of steam generator the fire grates being short and broad.
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 wherein groups of inclined water tubes are connected at
their ends to the inner walls of separate headers and are provided internally with

page_text: fire tubes that are connected to the outer waters of the headers so that the water
between the inner and outer tubes can be heated both from the inside and from the
outside, the several headers being connected with separate steam and water vessels
and provided with valves whereby any group of tubes with their corresponding
headers can, when desired, be shut off from the steam and water vessels, substantially
as described.
2. In a steam generator of the kind herein referred to, a vertically movable fire
grate connected with a damper controlling the passage of flame and hot gases to
the rear ends of the fire tubes and with a damper controlling a direct communication
between the furnace and the smoke box and chimney, the arrangement being such
that when the firegrate is moved into its raised position the first mentioned damper
will be opened and the other closed, and when the firegrate is lowered, the first
mentioned damper will be closed and the other opened, substantially as herein
described for the purpose specified.
3. My improved steam generator constructed arranged and operating substantially
Dated this 12th day of September 1896.
For the Applicant,
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.