Improvements in Apparatus for Promoting the Circulation of Water in Steam Generators and Boilers and Collecting the Solid Matter in same, and for Preventing the Formation of Scale.
Year: 1898

page_text: Improvements in Apparatus for Promoting the Circulation of Water
in Steam Generators and Boilers and Collecting the Solid Matter
in same,
and for Preventing the Formation of Scale.
We, HARRY SCHOFIELD, of 1A, Bryantwood Road, Drayton Park, N., Engineer,
and OLIVER PRESCOTT MACFARLANE, of 7, Hartham Road, Camden Road, N.,
Accountant, do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in apparatus for promoting or increas-
ing the circulation of the water in steam generators or boilers and also for
collecting the solid matter held in suspension in said water, or such solid matter
as may be stirred up by the effect of circulation and for preventing the formation
of scale.
In carrying out this invention we use preferably a pipe or similar conductor
fixed within the boiler and bent or formed in such a manner that the upper end
is situated a short distance below the working level of the water and as near as
it can conveniently be brought to the point where the greatest heat exists, while
the lower end of the pipe or conductor is carried to a point mear the bottom of the
boiler where the water has the lowest temperature. The continuity of the pipe
or conductor may be broken at any convenient point and one or more mud boxes
or cylinders introduced of greater sectional area than the pipe with the object
of reducing the velocity of the current passing through the mud boxes and allow-
ing the solid matter taken up by the water to be deposited therein; each mud
box or cylinder may be fitted with an internal baffle plate or plates and also a
sludge discharge pipe carried to any convenient point near the bottom of the mud
box or cylinder and passing through the boiler shell. This sludge pipe is fitted
with a tap or cock which may be opened when required in order that the sludge
may be blown through and deposited at some convenient point outside the boiler.
The pipe or conductor before mentioned is preferably made with the upper or dis-
charging end smaller in diameter than the lower end in order to increase the
current passing through it.
When Galloway or other cross tubes are fitted to the boiler furnaces the circu-
lation may be further increased by bridging over these cross furnace tubes, either
singly or in groups, transversely longitudinally or otherwise, with a breeches
piece or connector formed to close the upper ends of the cross furnace tubes and
having inlet and outlet apertures arranged to take the upper end of pipe or con-
ductor and the discharging nozzles respectively.
Instead of entirely closing the upper ends of the cross furnace tubes, pipes of
smaller diameter may be led from the breeches piece or connector down through
these furnace tubes and carried to any convenient point near the bottom of the
boiler. Or two or more of the cross furnace tubes may simply be bridged over or
otherwise connected together at the upper ends while the lower end of one or
more of the cross tubes may be partially closed or decreased in area in order to

page_text: promote the circulation of the water, such bridges or connectors may be fitted with
discharging nozzles at any convenient point.
It is obvious that one or more pipes or conductors may be fitted in the same
boiler, each having a separate mud box or one mud box of larger area may be
used to which all the pipes would be connected. The discharging end of the pipe
or connector, or nozzles fitted to breeches piece, may also be branched and formed
to lead jets of water to any desired position in the boiler.
24th January 1808
HARRY SCHOFIELD.
O. P. MACFARLANE.
Improvements in Apparatus for Promoting the Circulation of Water
in Steam Generators and Boilers and Collecting the Solid Matter
in same, and for Preventing the Formation of Scale.
We, HARRY SCHOFIELD, of 1A, Bryantwood Road, Drayton Park, N., Engineer,
and OLIVER PRESCOTT MACFARLANE, of 7, Hartham Road, Camden Road, N.,
Accountant, 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;-
This invention relates to apparatus for promoting or increasing the circulation
of the water in steam generators or boilers and also for collecting the solid matter
held in suspension in said water, and for preventing the formation of scale.
Our said invention is adapted for increasing the circulation of water in boilers
having Galloway and like tubes, and to this end we connect the upper ends of the
said Galloway tubes by a horizontal or curved connecting tube in which the
heated water ascending the Galloway tubes collects and from which it may be
discharged through any suitable arrangement of pipes or nozzles, the action being
further assisted by the intermittent escape of steam which also collects in the
upper part of the connecting tube.
The invention will be readily understood by reference to the accompanying s
drawings, in which:-
Figure 1 is a plan and
Figure 2 is an end view partly in section showing one of the simplest forms of
my improved circulating apparatus applied to two Galloway tubes in a Lancashire
boiler.
Figures 12 are respectively a plan and side view of a modification of the
apparatus shown in Figures 1 and 2.
Figure 3 is an end view and Figure 4 is a section on line a Figure 3 of another
modification of the apparatus shown in Figures 1 and 2.
Figure 5 is a side view, and
Figure 6 is a plan showing another form of our improved apparatus.
Figure 7 is a longitudinal section, and
Figure 8 an end view showing the combination of an apparatus of this kind,
with a water circulating and sediment collecting apparatus, of the kind herein-
after specified.
Referring more particularly to Figures 1 and 2:
4
A is the shell of the boiler, BB are the furnace flues, and CC are the Galloway
tubes which are welded into the tubes B transversely thereof in the usual manner.
a is the connecting tube of my improved apparatus, which tube may advan-
tageously be arranged as shown between the corresponding Galloway tubes of 5

page_text: a pair of furnaces, but may also extend between a pair of tubes of the same
furnace or otherwise. The said connecting tube has its extremities bent down-
wardly and provided with flanges a¹ which have a sweep or curvature such as will
enable them to fit over the upper ends of the Galloway tubes C.
The joint at these flanges does not require to be perfectly tight and it will suffice
if the flanges merely make a close fit with the crowns of the furnace flues B.
The said connecting tube a may be held in position by any suitable means,
such as by steel bands or straps surrounding the furnaces and overlapping the
flanges a or by stay rods connected to the boiler shell or to the tie bars of the
boiler.
a² are short projections or lugs secured around the inside of the ends of the con-
necting tube, and extending down into the end of the Galloway tubes, thus serving
to ensure the connecting tubes being truly central with regard to the Galloway
tubes.
6 is the discharge pipe which is secured to the pipe a about midway between the
ends thereof and at any suitable angle thereto, and which may have two or more
nozzles at its free end to better distribute the water discharged therefrom if
required.
In the modification shown in Figures 1 and 2, the horizontal tube a is replaced
by the curved tubes a³ ³ having their ends at one extremity bent down and pro-
vided with flanges al to fit over the upper ends of the Galloway tubes as pre-
viously described, and having their ends at the opposite extremity converging and
provided with flanges at, at and as a which are respectively bolted together as
shown to form the discharge pipe b, which latter may be only partly below the
water level of the boiler as shown by the dotted line.
This discharge pipe may be made to conduct the water discharged from the
tube a, or tubes a³ ³ as the case may be, to any desired part of the boiler, by
varying the length of such discharge pipe, or by fitting to it one or more suitable
nozzles.
The action of this form of apparatus is as follows:-
The highly heated water rising up the Galloway tubes C flows in two streams
towards the middle of the tube a or along the converging tubes a³, a³, and meeting
opposite the inner end of the pipe b is discharged therefrom as shown by the
arrows. At brief intervals however the foregoing action which depends only on
the convection currents is greatly augmented by the steam which collects in the
upper part of the tube a or tubes a³ ³ and escapes in gushes, when enough of it
has accumulated, through the pipe b, driving a large body of water before it with
considerable force. This steam is more particularly derived from bubbles formed
on the sides of the Galloway tubes where the furnace gases strike them.
Figures 3 and 4 indicate a modification of our apparatus in which the discharge
pipe is connected to the under side of the tube a and extends therefrom down
to the bottom of the boiler. The tube a is downwardly inclined towards its junc-
tion with the pipe b and furnished also at this point with a vent or opening a³ so
that the steam can escape therefrom.
In this case the circulation takes place up the Galloway tubes and down the
pipe b as indicated by the arrows, thus discharging highly heated water into the
bottom of the boiler and displacing the cold stagnant water that usually lies there.
Referring now to the apparatus shown in Figures 5 and 6, the arrangement
of the tube a is substantially as in the Figures 1 and 2, but instead of the pipe b
for the discharge of the water being connected direct to the cross tube it is formed
at the junction of two converging tubes 61 which lead into the downwardly bent
extremities of the tube a.
The ends of these tubes 61 project into the tube a for some little distance,
from the opposite side to that on which the furnace gases impinge. The purpose
of this is to direct the ascending stream of water into the tubes b₁ whilst however
allowing the bubbles of steam that form on the front of the Galloway tubes to
rise up into the cross tube a.

page_text: e is a pipe leading from the upper part or steam space of the tube a to an
injector-like jet or nozzle c¹ arranged within the pipe b.
The action in this case is substantially similar to that of the previous arrange-
ment, but the discharge of the steam which collects in the tube a takes place
through the pipe c and nozzle c¹ and sets up an injector action within the pipe
thus inducing a powerful flow of water through the tubes 6 and up the Galloway
tubes.
In the arrangement shown in Figures 7 and 8 the tubes are dispensed with,
and are replaced by a circulating apparatus such as that described in the Specifica-
tion of our former application for British Letters Patent No. 26286 dated the
11th November 1897. This latter apparatus briefly comprises a circulating
pipe a, a settling chamber or mud box and a discharge nozzle c*. In combin-
ing the present apparatus therewith a nozzle c¹ such as above described with
reference to Figures 5 and 6 but curved is led through the cover of the settling
chamber and is inserted into the rear of the nozzle c* so as to assist the latter
by its injection action.
Although in all the foregoing arrangements the cross pipe a or pipes a³ ³ are
arranged to close the upper ends of the Galloway tubes B, yet in some cases this
need not occur as the turned down ends of these tubes might be made smaller than
the Galloway tubes and be extended down through them and carried to any con-
venient point near the bottom of the boiler. The said ends thus reach the lower
and cooler parts of the boiler which are beyond the influence of the Galloway
tubes.
In some cases moreover the lower ends of the Galloway tubes may be partially
closed, preferably by means of a plate, such as 2, Figure 7, set at an angle so as
to guide the flow of water into the said tubes and to check any downward rush
of water that may occur when the steam in the connecting tube expands and
escapes in gushes in the manner before referred to. Although the connecting
pipes shown are applied only to a pair of Galloway tubes it will be readily under-
stood that pipes from several tubes may be led to a common collecting chamber
or device if desired.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:
1. An apparatus substantially as described for promoting circulation in steam
.boilers having Galloway or like tubes, comprising a connecting pipe or pipes
arranged to receive water ascending the said tubes and to discharge it in the
manner specified through a suitable outlet in any desired direction.
2. The combination of an apparatus of the kind referred to in the preceding
claim, with a circulation tube and settling chamber substantially as described.
3. An apparatus for promoting circulation in steam boilers, having its parts
arranged and operating substantially as herein before described with reference to
Figures 1 and 2, to Figures 1 and 24, to Figures 3 and 4, to Figures 5 and 6, or
to Figures 7 and 8 of the accompanying drawings.
Dated this 25th day of October 1898.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicants.