Improvements in Water Tube Boilers.
Year: 1897

page_text: Date of Application, 8th Oct., 1897
Complete Specification Left, 8th July, 1898-Accepted, 3rd Sept., 1898
PROVISIONAL SPECIFICATION.
Improvements in Water Tube Boilers.
I, BENJAMIN JOSEPH BARNARD MILLS, of 23, Southampton Buildings, in the
County of London, Patent Agent, do hereby declare the nature of this invention
(a communication to me from Emile Jolicard, Civil Engineer, of 8, Cours Charle-
magne, Lyons, in the Republic of France) to be as follows:-
The improvements forming the subject of the present application relate to
various arrangements of boilers, having inclined water tubes, and have for their
object the more perfect utilization of the surface of these tubes, by a more rational
circulation of the water passing through them.
In an inclined tubular group the lower tubes or those nearest the furnace, have
a much greater power of vaporization than the tubes of the upper rows and
should rationally possess a more active circulation; in boilers as hitherto arranged
it is the contrary which is produced, for the descending current which feeds the
tubes, tends to follow the lines of least resistance and to pass rather by the upper
tubes, or by those which are first met by the return of the water.
In order to remedy this fault, I give to the entrance of the circulation tubes,
cross sections, according to their distance from the grate, in order to proportion
as much as possible, the circulation, to the power of vaporization of each tube.
This result may be obtained in many ways, examples of which are shown in
the accompanying drawings.
The first method is particularly suitable for boilers having two collectors C
and 1, Fig. 1, connected by inclined tubes in which the water circulates in the
direction of the arrows. It consists in leaving the full section to the tubes T of
the lower row and in narrowing progressively the inlet to the upper tubes T1 T2 &c.
by rings or ferrules B' 132 &c., having their openings of more and more reduced
sections.
The second method is applicable to the circulation tubes placed in the interior
of the evaporation tubes, as in a boiler having a single collector C shown at
Fig. 2. It consists in leaving their entire section to the tubes of the upper
row T and in enlarging progressively the section of inlet of the lower tubes TTª
&c.
This enlargement may be obtained in a very simple manner by cutting the
extremities of the tubes at an angle more or less acute and by turning the
orifice towards the current of water. It is suitable in this case, to cut also in
the same way the opposite end of the tubes, in order to facilitate by a larger
section, the alteration of direction of the current of circulation. The proportional
distribution of the water is also favored by increasing progressively the diameter
of the tubes, at the same time as their section of inlet is increased as shown in
the figure.
The two methods described above may also be combined, by adopting for the
lower rows, the enlargement system of Fig. 2, and by narrowing the tubes of the
upper rows by rings or ferrules as shown in Fig. 1.

page_text: Considering that the tubes of the lower row or the first lower rows themselves
represent a large part of the total evaporation of the group, I have been led to
furnish these tubes with a special arrangement, allowing the easy and rapid
escape of the steam formed.
The arrangement shown in Fig. 3 consists of a vertical prolongation A adapted
to each of the vaporizing tubes V of the row or of the first lower rows, and dis-
charging above the water level y of the boiler.
The circulation tubes T placed in the interior of the tubes V discharge at their
respective levels, by traversing in E, the side of the prolonged tubes V.
The inlet of the tubes T is enlarged in the form of a funnel according to the
principle established above. The upper tubes T" receive one or the other of the
arrangements indicated above.
In some cases several evaporation tubes may be united in the same vertical
collector.
The section of inlet or exit of the tubes may be enlarged in various ways, for
example by enlarging their extremity in the form of a funnel as in Fig. 3, by
forming lateral holes therein, or by opening the tube after having split it as
shown in Fig. 4.
Dated October 8th
100%
;
I, BENJAMIN JOSEPH BARNARD MILLS, of 23, Southampton Buildings, in the
County of London, Patent Agent, do hereby declare the nature of this invention
(a communication to me from Emile Jolicard, Civil Engineer, of 8, Cours Charle-
magne, Lyons, in the Republic of France,) and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
The improvements forming the subject of the present application relate to
various arrangements of boilers having inclined water tubes, and have for their
object the more perfect utilization of the surface of these tubes by a more rational
circulation of the water passing through them.
In an inclined tubular group, the lower tubes, or those nearest the furnace, have
a much greater evaporating power than the tubes of the upper rows, and should
rationally possess a more active circulation. In boilers as hitherto arranged, it
is the contrary which is produced, for the descending current which feeds the
tubes tends to follow the lines of least resistance and to pass rather through the
upper tubes, or through those which are first met by the return of the water.
In order to remedy this fault I give to the entrance of the circulation tubes,
cross sections, according to their distance from the grate, in order to proportion
as much as possible the circulation to the evaporating power of each tube.
This result may be obtained in many ways, examples of which are shown in
the drawings accompanying my Provisional Specification.
The first method is particularly suitable for boilers having two collectors C
and D, Fig. 1, connected by inclined tubes in which the water circulates in the
direction of the arrows. It consists in leaving the full section to the tubes T of the
lower row, and in narrowing progressively the inlet to the upper tubes T, T³, &c.,
by rings or ferrules B1, B2, &c., having their openings of more and more reduced
sections.

page_text: The second method is applicable to the circulation tubes placed in the interior
of the evaporation tubes, as in a boiler having a single collector C, shown at
Fig. 2. It consists in leaving their entire section to the tubes of the upper
row T and in enlarging progressively the section of inlet of the lower tubes T¹, T3,
&c. This enlargement may be obtained in a very simple manner by cutting the
extremities of the tubes at an angle more or less acute and by turning the
orifice towards the current of water. It is suitable in this case, to cut also in
the same way the opposite end of the tubes, in order to facilitate by a larger
section the alteration of direction of the current of circulation. The proportional
distribution of the water is also favored by increasing progressively the diameter
of the tubes, at the same time as their inlet section is increased, as shown in
the figure.
The two methods described above may also be combined by adopting for the
lower rows, the enlargement system of Fig. 2, and by narrowing the tubes of the
upper rows by rings or ferrules as shown in Fig. 1.
Considering that the tubes of the lower row, or of the first lower rows, them-
selves represent a large part of the total evaporation of the group, the com-
municator has been led to furnish these tubes with a special arrangement allow-
ing the easy and rapid escape of .the steam formed.
The arrangement, shown in Fig. 3, consists of a vertical prolongation A adapted
to each of the evaporating tubes V of the lowest row, or of the first lower rows,
and discharging above the water level x, y, of the boiler. The circulation tubes T
placed in the interior of the tubes V discharge at their respective levels by
traversing in E the side of the prolonged tubes V.
The inlet of the tubes T is enlarged in the form of a funnel according to the
above established principle. The upper tubes T¹ receive one or the other of the
arrangements indicated above.
In some cases several evaporation tubes may be united in the same vertical
collector.
The section of inlet or exit of the tubes may be enlarged in various ways; for
example, by enlarging their extremity in the form of a funnel, as in Fig. 3, by
forming lateral holes therein, or by opening the tube after having split it, as
shown in Fig. 4.
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:.
-
The application to various systems of water tube boilers, of arrangements
having for their object to render the circulation of water in each tube proportional
to the power of evaporation of said tube, and to facilitate the disengagement of
steam formed in the lower tubes, these arrangements consisting:
(a) in narrowing the inlet of the tubes which evaporate the least.
(b) in enlarging the entrance of the tubes which evaporate the most and in
increasing their diameter when necessary.
(c) in prolonging the evaporating tubes of the lower row, or of the first lower
rows, above the water level;
the said arrangements being employed alone or in combination with one another
according to the kind of boiler to which they are applied, substantially as
described.
4150 K
dox
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DXVX
HARRIS & MILLS,
23, Southampton Buildings, London, Agents.