Improvements in or connected with Steam Generators or Bollers.
Year: 1893

page_text: Date of Application, 17th Jan., 1893.
Complete Specification Left, 17th Oct., 1893-Accepted, 18th Nov., 1893
PROVISIONAL SPECIFICATION.
Improvements in or connected with Steam Generators or Bollers.
I, ANTHONY SPENCER BOWER of St. Neots in the County of Huntingdon,
Engineer do hereby declare the nature of my invention to be as follows:-
In tubular boilers especially when forced draught is employed the tubes and tube
plates especially those upon which the products of combustion first impinge are
very liable to become overheated or even burnt through owing to the rapid
generation of steam leaving the tubes and plates unprotected by a sufficient body
of water. The tubes owing to this are also liable to lengthen and displace the tube
plate or become themselves displaced. It is the object of my invention to provide
means to obviate these objections. According to my invention I provide preferably
at or about the lower part of the water space of the boiler a tube having its one
end open to the water space say at one end of the boiler and its other end open to
the water space say at the other end of the boiler in which tube is mounted a
device which may resemble a helical conveyor which device on being rotated draws
water from one part say the rear end of the boiler and discharges it at another part
say the front end preferably into a space which is separated by a plate perforated
for the passage of the tubes. The rotation of the conveyor may be effected by any
suitable motor, it may be by the same apparatus that drives the blower or fan for the
forced draught so that the greater the draught the greater the circulation. The
motion may be transmitted to the conveyor directly or by gearing from the fan or
blower engine shaft or by a rope or band passing over a pulley on the spindle of
the conveyor which passes through a suitably packed gland in the boiler.
The feed water is preferably delivered at, near, or around this gland.
When the device is in operation water is drawn from say the rear of the boiler
and is forced into the space at say the furnace end of the tubes and thence is
delivered into the main body of the boiler to give such a circulation of the water
throughout the boiler as will cause such a body of water to be maintained over the
tubes and tube plates as will obviate the objections aforesaid. A plate or plates
or tube or tubes may be arranged between or around the boiler tubes to direct the
circulating water along and in contact with the outer surface of the tubes.
Although I have mentioned one tube containing a conveyor I may use one two
or more such tubes and conveyors each for example circulating water through the
whole, or any desired portion, of the boiler, for instance there may be tubes
extending from either end and terminating towards the mid portion of the lower
part of the boiler the conveyor blades being respectively reversely placed so that
the water is circulated from either end towards the middle setting up in effect a
double circulation. In this case the directing plates or tubes between or around
the boiler tubes as hereinbefore described may be duplicated at each end of the
boiler tubes.
n
71
1
T1902
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C., Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in or connected with Steam Generators or Boilers.
J, ANTHONY SPENCER BOWER of St. Neots in the County of Huntingdon
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 :-
In tubular boilers especially when forced draught is employed the tubes and tube
plates especially those upon which the products of combustion first impinge are
very liable to become overheated or even burnt through owing to the rapid
generation of steam leaving the tubes and plates unprotected by a sufficient body
The tubes owing to this are also liable to lengthen and displace the
tube plate or become themselves displaced. It is the object of my invention to
provide means to obviate these objections.
of water.
According to my invention I provide, preferably at or about the lower part of
the water space of the boiler, a tube having its one end open to the water space say
at one end of the boiler and its other end open to the water space say at the other
end of the boiler in which tube is mounted a device which may resemble a helical
conveyor which device on being rotated draws water from one part say the rear
end of the boiler and discharges it at another part say the front end preferably
into a space which is separated by a plate perforated for the passage of the tubes.
The rotation of the conveyor may be effected by any suitable motor, it may be by
the same apparatus that drives the blower or fan for the forced draught so that the
greater the draught the greater the circulation. The motion may be transmitted
to the conveyor directly or by gearing from the fan or blower engine shaft or by a
rope or band passing over a pulley on the spindle of the conveyor which passes
through a suitably packed gland in the boiler.
The feed water is preferably delivered at, near, or around this gland. When
the device is in operation water is drawn from say the rear of the boiler and is
forced into the space at say the furnace end of the tubes and thence is delivered
into the main body of the boiler to give such a circulation of the water throughout
the boiler as will cause such a body of water to be maintained over the tubes and
tube plates as will obviate the objections aforesaid. A. plate or plates or tube or
tubes may be arranged between or around the boiler tubes to direct the circulating
water along and in contact with the outer surface of the tubes.
Although I have mentioned one tube containing a conveyor I may use one two
or more such tubes and conveyors each for example circulating water through the
whole, or any desired portion, of the boiler; for instance there may be tubes
extending from either end and terminating towards the mid-portion of the lower
part of the boiler the conveyor blades being respectively reversely placed so that
the water is circulated from either end towards the middle setting up in effect a
double circulation. In this case the directing plates or tubes between or around
the boiler tubes as hereinbefore described may be duplicated at each end of the
boiler tubes.
And in order that my invention may be well understood I will explain with
reference to the accompanying drawings a manner in which it may be carried out
in practice.
Figure 1 is a longitudinal section through the line a b Figures 2 and 3.
Figures 2 & 3 are transverse sections each shewing half the boiler.
Figure 2 is a transverse section on the line c d Figure 1 and Figure 3 is a
transverse section on the line ef Figure 1.
The boiler shewn in the drawings is an ordinary double ended marine boiler but
the invention is not limited to that type of boiler. 1 are the furnaces whence the
gases emanating from the fuel pass into the combustion chambers, 2, to be there
completely burned before passing through the tubes 3, to the uptakes which are

page_text: not shewn in the drawings. 4, 5, are helical conveyors one with a left hand
helix the other with a right hand helix. The said conveyors are rotated in the
same direction by the shaft 6. mounted in bearings 7, 8, one of which may be closed
and the other be provided with a stuffing box as at 9, so as to make a water tight
closure. The shaft and conveyors may be rotated at any desired speed by a pulley
on the shaft 6 over which passes a belt or rope from the engine which drives the fan
for supplying the forced draught so that the greater the forced draught the
higher the speed of the conveyors and the more rapid the forced circulation, or the
conveyors may be actuated direct by a separate motor. 10, 11, 12, 13 are vertical
plates which may be fitted loosely in the boiler and extend completely across it, but
having therein passages for the boiler tubes 3, each of these passages being con-
siderably larger than the external area of the tubes so that there is an annular
space 14. between each boiler tube and the said vertical plates which rise to about
the ordinary water level in the boiler. The said vertical plates have also therein
large holes to allow the furnaces 1. to pass loosely through them, and the said
vertical plates are joined together at their lower parts by open ended tubes 15* 15°
in which the conveyors revolve. Two other vertical plates 16. 17 are placed round
the combustion chambers 2. and these last named plates are perforated towards their.
lower parts with numerous perforations 18. 19 is a strip of metal to confine the
rush of water caused by the conveyors and make it pass round and among the
tubes 3. This rush may be still further regulated and distributed by horizontal
perforated sheets of metal 20.
It will now be understood that if the conveyors be rotated in the direction of the
arrow Figure 2 a large volume of water many times that of the feed will be drawn
by the conveyors from between the ends of the boiler and the plates 10 and 13 and
be forced into the spaces between the plates 11, 16 and 17, 12. This water will
circulate all among the ends of the tubes 3, which are nearest to the combustion
chamber 2, and which in arrangements already existing where forced draught is
used are a continual source of trouble necessitating the use of false ferrules and
like devices. In like manner a continuous rapid circulation is kept over the tube
plates of the combustion chambers 2. The water or mixture of water and steam
now finds its way through the annular spaces 14, in the plates 11 and 12 thence
horizontally along the tubes 3. through the annular spaces 14, in the plates 10
and 13 and finally down to the open ends which are nearest to the ends of the
boiler, of the conveyor tubes, 15* 15 to be again circulated as before. Another
portion of the circulating water is forced through the perforations 18, of the
plates 16 and 17. This water circulates all over the combustion chambers 2.
ultimately finding its way over the edges of the plates 16, 17 round and among the
upper tubes 3, and along them to be again circulated by the conveyors. The
arrows indicate the species of circulation which this arrangement according to my
invention will effect. The feed water should preferably be admitted near one or
both of the shaft bearings 7 and 8. The circulation effected according to this
invention is positive and much in excess of that obtainable by ordinary methods
and it can be increased to suit extreme cases of forced draught so that in the case
of ships of war an enormous output of steam may be obtained safely without fear
of the tubes or tube plates giving way and without the use of such a device as false
tube ends which must of necessity reduce steaming power. The forced circulation
may be worked by a donkey boiler when getting up steam in the main boilers so
that the whole of the water in the boiler is heated uniformly thus avoiding the
strains which occur through unequal heating. In the case of a single ended boiler
the construction or arrangement may be the same as one half of the arrangement
described.
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 :-
1 T.
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33
MARRAGA
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page_text: establishing communication between different parts of the water space and having
therein a device or devices for drawing in water from one part of the water
space and discharging it at another part of the said space substantially as and
for the purposes hereinbefore described.
2. In steam generators or boilers a tube or tubes or passage or passages
establishing communication between different parts of the water space and having
therein a device or devices for drawing in water from one part of the water space
and discharging it at another part of the said space in combination with plates for
guiding the current or currents thus created over or amongst the tubes or tube
ends and tube plates or both over or amongst them and the combustion chamber or
chambers substantially as and for the purposes hereinbefore described.
3. The arrangement and combination of parts substantially as hereinbefore
described and shewn in the accompanying drawings.
Dated the 17th day of October 1893.
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, Agents.