Year: 1896

page_text: Date of Application (in United Kingdom), 12th Nov., 1906
Complete Specification Left, 12th Aug., 1897-Accepted, 18th Sept., 1897
Complete Specification Left, 12th Aug., 1897-Accepted, 18th Sept., 1897
We, LA COMPAGNIE DE LA CHAUDIÈRE MIXTE of 28 Rue Saint Lazare, l'aris,
France, represented by Louis Edmond Solignac, Director; do hereby declare the
nature of this Invention to be as follows:-
Circulation has heretofore been obtained in boilers in two ways, izby the
force of gravity or by propulsion effected by means of a pump or ejector, but
experience has shewn that, besides giving rise to serious objections, these means
cannot produce an active circulation.
The Invention which forms the subject of the present application for Letters
Patent has for its object to remedy these objections and in order that its
advantages over the means above mentioned may be readily understood we have
illustrated in Figure 1 of the accompanying drawing a type of boiler wherein the
circulation is dependent on the action of gravity. Figure 2 illustrates the
principle of our improved system, the means employed being represented dia-
grammatically in both figures.
In the arrangement of parts shewn in Figure 1 it will be seen that the water
in the position of rest fills all the parts of the apparatus below the water level a b
in the vessel A. On heating the nest of tubes T there is produced at their
central part which is the most exposed to the furnace heat and which part may
be considered as comprised between the two planes c d and e f globules of steam
tending to simultaneously force the water into the pipe g which supplies this
water to the header C and also into the header B connected with the discharge
pipes K whose upper ends open at J into the steam space A. The pipes
rising above the level a b in chamber,A great resistance is opposed to the dia-
charge of the water on account of the difference of level of the water and of the
overflow mouth J. The consequence of this twofold flow is that the circulation of
the steam takes place in the reverse direction to that which had been intended,
the pressure in header C and pipe 9 being less than that in header B in con-
sequence of the difference of height of the water level and of the orifice of pipe K.
Every time that the header B is emptied, equilibrium, is established between the
globules or pockets of steam in the nest of tubes and the chamber A, in which
case by the action of gravity a fresh quantity of water rushes. into the nest of
tubes and header B and causes a repetition of the objection above indicated. The

page_text: tubes T are therefore subjected to successive superheatings during the period of
upward flow and sudden coolings after the return of the water, the effect being
to prejudice the strength of the tubes. Attempts have been made to remedy the
objection, by placing in the water supply pipe, at 1) for example, a circulation
apparatus such as a pump, ejector, etc., but when the water circulating in the
apparatus attains the temperature corresponding to the pressure, a pump acts
imperfectly and the delivery is so reduced as to be insignificant, while an ejector
is incapable of working at such high temperatures.
The apparatus which we have invented and which forms the subject of the
present application, avoids the objections to the methods hereinbefore explained
and is represented in Figure 2 of the accompanying drawing. The apparatus
comprises :-
1
(1) A chamber A forming a reservoir of water and steam;
(2) An assemblage of tubes E in connection by their opposite ends with the
headers B and C, the end of each tube where it enters the header C being
provided with a reducing ferrule;
(3) One or more pipes K extending down to near the bottom of header B and
upwards into the steam chamber A to point J;
(4) A pipe g connecting header C with chamber A the lower end of said pipe
opening into a box H provided with a balanced non-return valve for preventing
the water passing from C to A;
(5) A pipe m of small diameter connecting valve box H with the crown of a
domerising from reservoir A.
Thus arranged, on heating the tubes there is also formed in the portion com-
prised between the planes c d and e f pockets or globules of steam which tend
to force the water into the headers B and C whence it rises simultaneously in
pipes and m and the balanced valve p in box H closes. Owing to the sinall
sectional area of pipe m the rise therein of the water to the level of J only
necessitates a very slight backward flow of the water in the tubes E. The reducing
ferrules considerably retard the flow of the water in the reverse direction to
that of the normal circulation. This is important, as the choking of the sectional
area of the tubes at the ferrules assists in directing the flow of the water through
pipe K. Thenceforth the backward flow ceases and the steam having for abut-
ment the valve p and the liquid column which rises in tube m and the ends of
the ferrules, drives out into reservoir A the whole of the liquid contained in
header B. Equilibrium of pressure is then established between the tubes and
valve box H at the back of the valve p. The valve now opens, permitting the
refilling of the header C, the ferrules allowing the water to flow freely during
the period of equilibrium, and thenceforth the circulation is definitely established
in the predetermined direction. The ferrules further serve to limit to the
minimum requisite for ensuring an efficient vapourization the quantity of water
in action and consequently facilitates the operation of discharge through pipe K.
Dated this 12th day of November 1896.
A. M. & WM. CLARK,
53, Chancery Lane, London, Chartered Patent Agents.

page_text: 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 :-
Circulation has heretofore been obtained in boilers in two ways, riz::by the
force of gravity or by propulsion effected by means of a pump or ejector, bat
experience has shewn that, besides giving rise to serious objections, these means
cannot produce an active circulation.
The Invention which forms the subject of the present application for Letters
Patent has for its object to remedy these objections and in order that its
advantages over the means above mentioned may be readily understood we have
illustrated in Figure 1 of the drawing accompanying our Provisional Specifica-
tion a type of boiler wherein the circulation is dependent on the action of gravity.
Figure 2 illustrates the principle of our improved system, the means employed
being represented diagrammatically in both figures.
In the arrangement of parts shewn in Figure 1 it will be seen that the water
in the position of rest fills all the parts of the apparatus below the water level a b
in the vessel A. On heating the nest of tubes T there is produced at their
central part which is the most exposed to the furnace heat and which part may
be considered as comprised between the two planes c d and e f globules of steam
tending to simultaneously force the water into the pipe g which supplies this
water to the header C and also into the header B connected with the discharge
pipes K whose upper ends open at J into the steam space A. The pipes
rising above the level a b in chamber, A great resistance is opposed to the dis-
charge of the water on account of the difference of level of the water and of the
overflow mouth J. The consequence of this twofold flow is that the circulation of
the steam takes place in the reverse direction to that which has been intended,
the pressure in header C and pipe being less than that in header B in con
sequence of the difference of height of the water level and of the orifice of pipe K.
Every time that the header B is emptied, equilibrium is established between the
globules or pockets of steam in the nest of tubes and the chamber A, in which
case by the action of gravity a fresh quantity of water rushes into the nest of
tubes and header B and causes a repetition of the objection above indicated. The
tubes T are therefore subjected to successive superheatings during the period of
upward flow and sudden coolings after the return of the water, the effect being
to prejudice the strength of the tubes. Attempts have been made to remedy the
objection, by placing in the water supply pipe, at 1) for example, a circulation
apparatus such as a pump, ejector, etc., but when the water circulating in the
apparatus attains the temperature corresponding to the pressure, a 'pump acts
imperfectly and the delivery is so reduced as to be insignificant, while an ejector
is incapable of working at such high temperatures.
The apparatus which we have invented and which forms the subject of the
present application, avoids the objections to the methods herein before described
and is represented in Figure 2 of the drawing. The apparatus comprises :--
(1) A chamber A forming a reservoir of water and steam;
(2) An assemblage of tubes E in connection by their opposite ends with the
headers B and C, the end of each tube where it enters the header C being
provided with a reducing ferrule r;
(3) One or more pipes K extending down to near the bottom of header B and
upwards into the steam chamber A to point J;
(4) A pipe g connecting header C with chamber A the lower end of said pipe
cpening into a box H provided with a balanced non-return valve p for preventing
the water passing from C to A;
(5) A pipe m of small diameter connecting valve box H with the crown of a
domerising from reservoir A.
Thus arranged, on heating the nest of tubes there is also formed in the portion
comprised between the planes c d and e f pockets or globules of steam which
tend to force the water into the headers B and C whence it rises simultaneously

page_text: in pipes and m and the balanced valve in box, H closes. Owing to the small
sectional area of pipe m the rise therein of the water to the level of orifice J of
pipe only necessitates a very slight backward flow of the water in the nest of
tubes. E. The reducing ferrules r considerably retard' the flow of the water in
the reverse direction to that of the normal circulation. This is important, as the
choking of the sectional area of the tubes at the ferrules assists in directing the
flow of the water through pipe K. Thenceforth the backward flow of water
ceases and the steam having for abutment the valve and the liquid column
which rises in tube m and the ends of the ferrules, drives out into reservoir A
the whole of the liquid contained in header B. Equilibrium of pressure is then
established between the nest of tubes and valve box H at the back of the valve p.
The valve now opens, permitting the refilling of the header C, the ferrules
allowing the water to flow freely during the period of equilibrium, and thence
forth the circulation is definitely established 'in the predetermined direction.
The ferrules further serve to limit to the minimum requisite for ensuring an
efficient vapourization the quantity of water in action and consequently facilitate
the operation of discharge through pipe K.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performer e declare that what
we claim is:
.1. A steam boiler with forced circulation, comprising an assemblage of tubes
each, provided at its front end with a reducing ferrule for the purpose of retarding
the flow of the water in the reverse direction to that of the normal circulation
and also assist in directing the flow through pipe K.
2. In a steam boiler with forced circulation, comprising an assemblage of tubes
each provided, at its front end with a reducing ferrule for the purpose of retarding
the flow of the water in the reverse direction to that of the normal circulation
and also assist in directing the flow through pipe K the combination of :-
(a) A receiver for the fluid which has traversed the assemblage of tubes
preferably arranged as described;">
(b) A balance valve placed in the pipe leading from the reservoir to the feed
header;
(c) Ferrules of small diameter placed in the ends of the vapourizing tubes;
and
(d) A pipe of small diameter rising from the top of the feed header above the
level of the steam exit pipe and connecting with a dome on the reservoir A;
all as herein before described and for the purpose specified.
Dated this 12th day of August 1897:
A. M. & WM. CLARK,..
53; Chancery Lane, London, Chartered Patent Agents.