Improvements in and relating to Steam Generators.
Year: 1892

page_text: Date of Application, 10th Mar., 1892
Complete Specification Left, 12th Dec., 1392-Accepted, 10th Mar., 1893
PROVISIONAL SPECIFICATION.
Improvements in and relating to Steam Generators.
I, ALFRED HENRY CROCKFORD, of Bridge House, Crayford, in the County
of Kent, Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to steam generators, and is designed to increase the
evaporative power thereof and to promote the circulation of the water therein.
My said invention is advantageously applicable to Lancashire boilers and to
other boilers having the furnace tube or tubes extending through the same and
connected with external return flues.
For
An important object of my present invention is to utilize the heat of the products
of combustion on their passage through the external return flues, which heat would
otherwise be absorbed to a great extent by the exterior walls of such flues.
this purpose, I arrange within each of the said return flues, a multi-tubular
extension of the generator. For instance, in each of the said flues, I arrange near
the exterior wall thereof, horizontal or approximately horizontal tubes arranged
one above another and connected by a large number of vertical tubes of smaller
diameter. These series or groups of tubes are so connected with the boiler that the
water will flow from the lower part thereof first through the lower horizontal tubes
and then through the vertical tubes to the upper horizontal tubes and thence back
into the boiler at or near the water-level therein. The said tubes are, moreover,
preferably so arranged that the water will flow from the boiler at one end thereof
and will return to the boiler at the other end thereof. I also prefer to construct
and arrange each series or group of tubes in such a manner that it can be readily
connected with and disconnected from the boiler, and can be easily introduced into
and withdrawn from the flue.
I find it advantageous to connect the vertical tubes with the horizontal tubes in
such a manner that, in case of need, either of the said vertical tubes can be,
detached from the horizontal tubes and a new tube fitted in its place, without the
necessity for disturbing any of the other tubes of the series. For instance, I bend
the vertical tubes in a suitable manner and connect the same at one end to the top
of the corresponding horizontal tube, and at the other end to one side of the other
horizontal tube.
To promote the circulation of the water through the aforesaid multi-tubular,
extensions of the generator, I sometimes provide for the introduction into the return
ends of the horizontal tubes, of jets of steam from the steam-space of the generator.
I thus obtain a forced circulation of the water. For this purpose, I find it
advantageous to conduct the steam from the steam-space of the generator through
a suitable pipe and branch-pipes provided with stop cocks or valves, to nozzles
arranged within the return ends of the horizontal tubes in such a manner that the
jets of steam will be directed into the boiler. By means of the aforesaid cocks or
valves, the circulation of the water can to some extent be regulated.
It is evident that I can, if desired, somewhat modify the arrangement of the
aforesaid tubes without departing from the nature of my said invention.
Dated this 10th day of March 1891.
A. H. CROCKFORD.
D. Young & Co.,
11 & 12, Southampton Buildings, London, W.C.,
Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in and relating to Steam Generators.
I, ALFRED HENRY CROCKFORD, of Bridge House, Crayford, in the County
of Kent, 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 :-
My invention relates to steam-generators and is designed to increase the
evaporative power thereof and to promote the circulation of the water therein.
My said invention is advantageously applicable to Lancashire boilers and to other
boilers having the furnace tube or tubes extending through the same and connected
with external return flues.
An important object of my present invention is to utilize the heat of the pro-
ducts of combustion on their passage through the external return flues, which heat
would otherwise be absorbed to a great extent by the exterior walls of such flues.
For this purpose I arrange within each of the said return flues, a multitubular
extension of the generator. For instance, in each of the said flues, I arrange near
the exterior wall thereof horizontal or approximately horizontal tubes arranged
one above another and connected by a large number of vertical tubes of smaller
diameter. These series or groups of tubes are so connected with the boiler that
the water will flow from the lower part thereof first through the lower horizontal
tubes and then through the vertical tubes to the upper horizontal tubes and thence
back into the boiler at or near the water-level therein. The said tubes are, more-
over, preferably so arranged that the water will flow from the boiler at one end
thereof and will return to the boiler at the other end thereof. I also prefer to
construct and arrange each series or group of tubes in such a manner that it can
be readily connected with and disconnected from the boiler and can be easily intro-
duced into and withdrawn from the flue. The water in these series of tubes being
more highly heated than that in the lower part of the boiler, a very rapid
circulation of the water will take place.
I find it advantageous to connect the vertical tubes with the horizontal tubes in
such a manner that, in case of need, either of the said vertical tubes can be
detached from the horizontal tubes and a new tube fitted in its place, without the
necessity for disturbing any of the other tubes of the series. For instance, I bend
the vertical tubes in a suitable manner and connect the same at one end to the top
or to the bottom of the corresponding horizontal tube, and at the other end to one
side of the other horizontal tube.
To promote the circulation of the water through the aforesaid multitubular
extensions of the generator, I sometimes provide for the introduction into the
return ends of the horizontal tubes, of jets of steam from the steam-space of the
generator. I thus obtain a forced circulation of the water.
In the accompanying drawings I have shown how my said invention may be
conveniently and advantageously carried into practice.
Figure 1 is a front elevation, and
Figure 2 a plan, partly in horizontal section, showing a Lancashire boiler with
my improved apparatus applied thereto.
Figure 3 is a rear elevation, partly in vertical section, showing another arrange-
ment of my improved apparatus, and
Figure 4 is a section on the line, x, Figure 3.
Figure 5 is a horizontal section, showing one form of nozzle whereby steam is
admitted into the upper horizontal tubes as hereinafter described, and
Figure 6 is an elevation, partly in section, illustrating a further modification of
my invention.
Like letters indicate corresponding parts throughout the drawings.

page_text: A is the boiler. B, B are the internal furnace tubes or flues and C, C are the
external return flues thereof. D is a mud-drum or sediment collector. E is the
scating of the said boiler.
a, a are the upper horizontal tubes and b, b the lower horizontal tubes of my
multitubular extensions; c, c are the smaller vertical tubes through which com-
munication is established between, the tubes a and b, and which are arranged at
suitable distances apart as shown more clearly in Figure 4.
In the arrangements shown in Figures 1 and 2 and in Figures 3 and 4, the con-
nections with the boiler are made as follows, viz. -The lower part of the boiler
is connected by a pipe d, extending through a stuffing-box e, with the mud-drum or
sediment-collector D, which is connected by pipes with the lower horizontal
tubes b, at the back end of the boiler. The upper horizontal tubes a are connected
by pipes a with the upper part of the boiler at the front end thereof.
The tubes a, b and c being more highly heated than the lower part of the boiler,
an energetic circulation of the water is produced, the water flowing from the
bottom of the boiler through the pipe d into the sediment collector D, thence
through the pipes into the lower horizontal tubes and through the vertical
pipes c into the upper horizontal tubes a, whence it returns to the boiler through
the pipes a'.
For the purpose of obtaining a forced circulation of water, I find it advantageous
to conduct the steam from the steam-space of the generator A through a suitable
pipe (Figures 1 and 2) and branch-pipes provided with stop cocks or valves g,
to nozzles arranged within the return ends a' of the horizontal tubes a in such a
manner that, when the valves are opened, jets of steam will be directed by the
said nozzles into the boiler so as to draw the water into the same from the tubes a.
By means of the aforesaid cocks or valves g, the circulation of the water can to
some extent be regulated.
In the arrangement of my improved apparatus shown in Figures 3 and 4, I
provide means whereby jets of steam will be automatically caused to enter the
ingress ends of the tubes a when the water in the boiler has fallen below a pre-
determined level. For this purpose, a pipe is connected with the rear end of the
boiler at a point a short distance below the ordinary water-level, and also, by means
of branch-pipes j', with nozzles in the tubes «, so that, when the water-level falls
below the said point, steain passes through the nozzles and the circulation is
thereby increased.
Figure 5 shows the steam nozzle k, arranged in the ingress end of one of the
upper horizontal tubes a.
Figure 6 shows a modified arrangement of the connections between the sediment
collector D, the boiler, and the lower horizontal tubes b, whereby the cooler water
descends from the boiler by the pipe d into the centre of the sediment collector,
and leaves the same at the top near the ends thereof by the pipes .
In constructing my improved apparatus I prefer to fix the multitubular extensions
to cast-iron doors at the front of the return flues C, in such a manner that they
may be disconnected from the boiler and withdrawn from the flues C for cleaning
or repairing the said tubes or the flue.
It will be seen that the vertical tubes c are secured to the top of the lower
horizontal tubes b and are bent or curved near their upper ends which are secured
to the upper horizontal tubes a in such a manner that either of the vertical tubes c
of the series can be removed and replaced without disturbing the other tubes of the
series.
m is a blow-off cock, which may, if necessary, be provided upon each of the
tubes b to permit the discharge of any sediment that may accumulate therein.
It is evident that I can, if desired, somewhat modify the arrangement of the
aforesaid tubes of the multitubular extension without departing from my improved
method of augmenting the circulation and the evaporative power of a boiler.
Moreover my improved multitubular extensions above described may, if desired,
be used (with or without the steam jet or jets) in combination with externally fired

page_text: boilers, the said multitubular extensions, in this case, being preferably arranged one
at each side of the furnace within the same.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is
First. The method of providing for the better circulation of water in an
internally fired steam-generator and for the more efficient utilization of the heat
applied thereto, by the use of one or more multitubular extensions arranged in the
external return flue or flues thereof and connected with the said generator sub-
stantially as above specified.
Second. The combination, with a steam-generator, of a multitubular extension
thereof, consisting of horizontal tubes arranged one above the other and communi-
cating with each other through vertical tubes of smaller diameter, substantially as
hereinbefore described, and for the purposes specified.
Third. The combination, with a steam-generator and a multitubular extension
thereof, of means whereby a jet or jets of steam may be used when required to
increase the circulation of the water, substantially as described.
Fourth. The combination, with a steam-generator and a multitubular extension
thereof, of a device whereby the circulation of the water will be automatically
increased by the action of a jet or jets of steam when the water in the said generator
falls below a predetermined level, substantially as described.
Fifth. The multitubular extension so connected with a door for closing the flue
and with the steam-generator that it may be readily disconnected from the generator
and withdrawn with the said door from the flue, as, and for the purposes, aboye
specified.
Sixth. The improved apparatus (with or without the mud-drum or sediment
collector) constructed and combined with the steam-generator, substantially as
described with reference to either of the arrangements illustrated in the accom-
panying drawings and operating as, and for the purposes, above specified.
Dated the 12th day of December 1892
D. YOUNG & Co.,
11 & 12, Southampton Buildings, London, W.C.,
Agents for the Applicant.