IMPROVEMENTS IN OR CONNECTED WITH STEAM BOILERS
Year: 1872

page_text: LETTERS PATENT to Richard Mill, of Jersey, one of the Channel
Islands, for the Invention of "IMPROVEMENTS IN OR CONNECTED WITH
STEAM BOILERS."
Scaled the 28th January 1873, and dated the 8th August 1872.
PROVISIONAL SPECIFICATION left by the said Richard Mill at the
Office of the Commissioners of Patents, with his Petition, on tho
8th August 1872.
I, RICHARD MILL, of Jersey, one of the Channel Islands, do hereby
3 declare the nature of the said Invention for "IMPROVEMENTS IN OR CON-
NECTED WITH STEAM BOILERS," to be as follows :—
The primary object of my Invention is to increase the heating
surface of steam boilers, more particularly those called Cornish and
egg-ended, and the subsidiary object is in some cases to heat the feed
water.

page_text: pipes (say from 1½ inches upwards in diameter) over the grate and
placed close against the crown of the furnace. One system I connect
to one side of the front of the boiler by carrying a pipe thence up and
into the steam, the other system I connect similarly to the other side.
Each system consists of a pipe led backwards and forwards serpentine
fashion. At the back each system is connected to the water space over
the furnace crown, or at the sides thereof, at or near the back end of
same, so that there is a continuous flow of water from that place to the
front of the boiler. The two systems may be connected together at the
back by a T picce so that there is only one water communication hole
to make in the furnace crown in that case. Or the pipe systems may be
connected in front to the water space and behind to the steam space. I
support the pipes by suitable iron brackets, stays, or bridges, and screw
them together with iron sockets and elbows, preferably U shaped, so as
to ensure a free circulation.
In order to keep the pipes clean I connect a blow-off pipe and cock
to the pipe at cach side of the front of the boiler. When the steam
is not up water may then be run through to the blow off as required.
Or in order to blow through more efficiently when steam is up I put a
cock on cach pipe in front of the boiler between the exit from the
boiler and the entrance to the steam space of the boiler. When shutting
this cock and opening the corresponding blow-off cock the water will
rush out from the back of the boiler through the pipe system and out at
the front.
This Invention may also be applied to steam boilers in order to serve
as a feed water heater. The feed water pipe is then connected to the
pipes in the back part of the fire-box tube.
In some cases the pipe systems may be continued so that one or more
pairs of pipes are carried from one end of the grate to the other, resting
on the fire-bars in order to preserve them from burning away and to
increase the heating surface. Or the pipe system on the grate may
be separate from the other pipe system, and in that case I connect the
pair or pairs of pipes on the grate to the water space at the fore end of
boiler by a pipe.
For egg-ended boilers I arrange a pipe system vertically on cach side
whoh the side walls nun nombrated
1

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Richard Mill in the Great Seal Patent Office on
the Sth February 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
MILL, of Jersey, one of the Channel Islands, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing dato the Eighth day of August, in the year of
our Lord One thousand eight hundred and seventy-two, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Richard Mill, Her special licence that
I, the said Richard, Mill, my executors, administrators, and assigns,
or such others as I, the said Richard Mill, my executors, adminis-
trators, and assigns, should at any time agree with, and no others, from
time to time and at all times thereafter during the term therein expressed,
should and lawfully might make, use, exercise, and vend, within the
United Kingdom of Great Britain and Ircland, the Channel Islands,
and Isle of Man, an Invention for "IMPROVEMENTS IN OR CONNECTED WITH
STEAM BOILERS," upon the condition (amongst others) that I, the said
Richard Mill, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and scals, should
particularly describe and ascertain the nature of the said Invention, and
in what manner the same was to be performed, and cause the same to be
filed in the Great Seal Patent Office within six calendar months.next
and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Richard Mill, do hereby declaro
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement, reference being had to the accompanying
Drawings, and to the letters of reference marked thereon, that is to
say:-
The primary object of my Invention is to increase the heating surface
of steam boilers, more particularly those called "Cornish" and " egg-
ended" boilers, and the subsidiary object is in some cases to heat the
feed water.
C
The nature of my Invention is as follows;-I will first describe it
with reference to an ordinary Cornish boiler. I arrange two systems of

page_text: For egg-ended boilers I arrange a pipe system vertically on cach side
of the grate, whereby the side walls are protected.
•
And in order that my said Invention may be fully understood, I shall
proceed to describe the same with reference to the accompanying Sheet
of Drawings, which represent various modes of carrying out my said
Invention.
Figure 1 is a vertical section through an ordinary Cornish boiler
Figure 2 is a horizontal section through the flue of the same; and
Figure 3 is a front elevation of a boiler fitted with my pipe systems.
I may here mention that I find the following sizes of pipes to be suit-
able, viz., for a 2 foot flue I recommend 2.inch steam tubing; for a
2 foot 6 inch flue I use 2 inch tubing; and for a 3 foot flue, 3 inch
tubing, and so on, about in the proportion of 1 inch tube internal
diameter per foot diameter of fluc.
A, B, C, and A', B', C', are the two pipe systems, each consisting of
three pipes joined by double bends. By making the pipes of a smaller
diameter than aforesaid, or by placing them closer together, more than
three pipes may be used in each system. The two systems are arranged
over the grate, as shown, and in this case placed so as to leave some
space between them and the crown of the furnace. I find this advan-
tageous, as the flame in that case can play well round the pipes. Each
system is connected with its side of the boiler, namely, at the back the
pipes C and C¹ terminate into the water space above the crown of the
furnace, at or near the end, and at the front the pipes A and A' may be
connected to the steam space, or it may be just at the water level, or
below the same; or the connections might be made at the front of the
boiler. It is here on Fig. 3 shewn as terminating at D, near the
bottom of the fluc, where it is out of the way of the gauge fittings. E is
a cock which I call the circulation cock; and F is the blow-off cock.
By shutting the former and opening the latter the pipe system may bo
cleared of any sediment that may have collected.
I prefer to connect the feed as shown at G, as in that case the feed
water is passed through one of the pipe systems and becomes. heated
thereby, but the feed may if desired be connected at II or at L, in which
case it would not pass through the pipe system unless the circulation
cock was open. In the former cases when connected at G or H, the
feed water would always pass through the pipe system whether the

page_text: circulation cock be open or shut. The pipes are supported by suitable
brackets or stays as shown.
"
Figure 4 is a separate plan view of the brackets a; Fig. 5, a similar
view of the brackets b; and Fig. 6 a similar view of the brackets c;
but other forms may be used as desired and required.
Figure 7 is a front clevation of a Cornish boiler fitted with the two
pipe systems described, with reference to Figs. 1, 2, and 3; but in
this case no circulation cock is used, and the pipes A and A' are always
in communication with the lower part of the water space. They may
be fitted with blow-off cocks or with plugs fand ƒ¹ for convenience of
cleaning. The feed pipe may be connected to one of the pipes if desired
and even if the feed is shut off the pipe system will still be supplied with
water from the boiler. In this view is also shewn the application of
another kind of pipe system in the centre of the fluc. This apparatus
will be described with reference to Fig. 8.
It is obvious that the just described arrangement may be applied with
equal advantage to Lancashire or other boilers with furnace flues.
For marine boilers both of the ordinary low pressure type and of the
now somewhat usual high pressure type with circular furnace flues, this
Invention is particularly applicable as it not only saves a considerable
amount of fuel but reduces the stoke hole temperature, because a great
part of the heat now radiating and diffusing itself into the stoke hole to
the great distress of the stokers would by the use of this Invention be
utilized.
As aforesaid the two systems may be connected at the back by a T
piece, but I prefer the mode here shewn. The pipe systems may be
connected to the upper part of the water space or to the steam space in
front while they are connected to the lower part of the water space at
the back, but I prefer the mode here shown.
Figure 8 is a vertical longitudinal section of a furnace flue for a
Cornish, Lancashire, marine or other furnace flue boiler. In this case
one or more pipe systems are arranged so that the lower limb or tube
branch of each rests on the grate or nearly so in order to preserve the
furnace bars and to increase the heating surface.
Figure 7 is a front elevation of boiler; D is the lower pipe which by
the pipe F is connected to the water space in the lower part of the boiler

page_text: at the bridge end of the ash-pit by a flange as shown. Where it passes
through the grate one or more bars is or are made shorter to allow it to
pass through, and the back end of such bars must then be supported by
any convenient or suitable means from the adjoining bars or otherwise.
E is the upper pipe which is carried along to the back of the boiler, and·
there terminates in the water space at the upper part of the furnace fluc.
This arrangement of pipe system may for very small furnace flues be
used alone, but for larger furnace flues it may be used in combination.
with the pipe systems described with reference to Figs. 1, 2, and 3.
In the latter case the pipe system D, E, F, described with reference to
Fig. 8 may then be connected to or be separate and independant from
the other systems A, B, C, and A', B¹, C. Figure 7 is a front elevation
of a Cornish boiler fitted in that manner, that is with one central pipo
system E, D, F, and two side systems A, B, C, and A', B', C¹, each indo-
pendant of the other.
Figure 9 is a vertical longitudinal section through an egg-ended boiler
having two pipe systems, one on cach side applied thereto. This pipe
arrangement is similar to the A, B, C, pipe system previously described
only that the pipes here are arranged vertically or slanting one above
the other, but so as to leave the middle of the furnace clear. I, K,
and L are three pipes connected together by double bends. The pipe I
runs along the whole length of under side boiler and has its exit and
is connected to the water space at the back end of the bottom of the
boiler, the pipes K and L are arranged under the same but only in the
furnace part of the flue, the pipe L runs to the front of the brickwórk
and is there connected to the pipe M which has its exit in the steam
space or the water space in the upper part of the boiler. The pipes L
and Marc connected to each other and are made convenient for feed
pipe and blow off connections by means of T picce or four way piece as
shown. N is the circulation cock; and O is the blow-off cock. The
working of the blow-off and circulation arrangement is the same as
described with reference to Figs. 1, 2, and 3.
•
Figure 10 is a vertical longitudinal section through an egg-ended
boiler having two pipe systems somewhat similar to those just described,
but the pipe M is in this case placed inside the brickwork instead of in
the front of the boiler and has no circulation cock. The outer end of
the pipe L may have a T piece for connecting the feed pipe and the blow-
off cock if desired.

page_text: An
For clephant boilers and other boilers fired underneath the pipe
systems just described may be applied in a similar manner.
important advantage resulting from the application to such boilers
besides the economy in fuel is the preservation of the side walls of the
furnace. The pipes may in some cases be bent into the required form, 5
and not be screwed together by means of bends and sockets.
And having now fully described the nature of this Invention, and
several modes of carrying the same into effect, I declare that I claim as
my improvements in or connected with steam boilers.
Firstly. The application to steam boilers of a pipe system or systems 1
separately or connected or combined, and each consisting of a series of
continuous pipes or tubing having one end connected to the front end of
the boiler, and the other to the back end of the boiler in such manner
that one of said ends has its exit in the lower part of the water space,
and the other in the upper part of the water space or in the steam space, 1
all substantially as herein-before set forth.
Secondly. The combination of such pipe system or systems with feed
circulation and blow-off apparatus, all substantially as herein-before set
forth.
In witness whereof, I, the said Richard Mill, have hercunto set my 2
hand and seal, this Sixth day of February, in the year of our
Lord. One thousand cight hundred and seventy-three.