Improvements in Apparatus for Automatically Regulating the Supply of Feed Water to Steam Boilers.
Year: 1899

page_text: Date of Application, 13th Oct., 1899
Complete Specification Left, 13th July, 1900-Accepted, 8th Sept., 1900
PROVISIONAL SPECIFICATION.
Improvements in Apparatus for Automatically Regulating the
Supply of Feed Water to Steam Boilers.
I, ERNEST LATHAM, of 3, Berlin Road, Catford Bridge, in the County of
Kent, Engineer, do hereby declare the nature of this invention to be as follows:-
This invention has reference to apparatus whereby the working of a feed
pump for supplying feed water to a steam boiler can be controlled in an auto-
matic manner according to the height of the water in the said boiler.
According to one construction the working of the feed pump is controlled
by a piston that is connected to a suitable moving part of the pump, is formed
with a small hole or passage therethrough, and is arranged to reciprocate in a
cylinder that is fixed in a horizontal or nearly horizontal position with its
axis at or near the normal water level in the boiler, is in communication at
one side of the piston with both the steam and water spaces of the boiler, and
is provided with a restricted connecting passage and a controlling valve therefor
whereby the two ends of the cylinder can be placed in communication with
each other, the arrangement is such that when the water level in the steam
generator falls below the normal, the cylinder will be filled with steam some
of which passing through the hole in the piston to the opposite side thereof,
will place the piston nearly in equilibrium and allow it and the pump to be
worked at full speed, and when the water rises in the boiler above the normal
water level it will enter both ends of the cylinder and impede the reciprocation
of the piston therein and thereby offer a resistance that will retard and ultimately.
stop the pump and consequently the supply of feed water to the steam boiler.
In one arrangement the cylinder is arranged in a position slightly inclined to
the horizontal and is attached to the steam boiler casing at a height corre-
sponding to or about the normal water level, by a bracket, which may be of cast
iron and forms the cylinder cover, the other or outer end of the cylinder being
provided with a stuffing box through which passes a piston rod the outer end
of which is connected by a link to one arm of a bell crank lever pivoted to an
extension or projection on the cylinder, the other arm being connected to a
reciprocating part of a duplex pump. Within the cylinder is a piston formed
near its upper part with a small hole that places the parts of the cylinders at
opposite sides of the piston in communication with each other.
On the upper
and lower sides of the cylinder and near the inner end thereof are formed hollow
branches to which are secured pipes which lead respectively to the steam space,
and water space of the steam boiler. The pipe leading to the water space of the
boiler is also in communication with the outer end of the cylinder by means of a
passage of small cross section (hereinafter called the controlling passage) formed
in the wall of the cylinder and adapted to be controlled by a cone-shaped valve
carried by a rod that extends through a stuffing box and is capable of being
adjusted from the exterior of the cylinder so as to regulate the effective cross
sectional area of the controlling passage. The arrangement of the apparatus is
such that when the water level in the steam generator falls below the normal,
the cylinder will become filled with steam some of which will pass from one side
' מ'
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page_text: of the piston to the other through the small hole therein and so allow of the
piston and pump being reciprocated freely and at full speed. When the level
of the water in the boiler rises the cylinder will be gradually filled and the
action of the piston impeded the water at the inner end of the cylinder being
easily forced back into the cylinder through the lower water pipe on the instroke
of the piston but that at the outer end which has to pass through the restricted
controlling passage which will offer considerable resistance to the outward
movement of the water and consequently to the piston and thus automatically
stop the pump which however will automatically restart as soon as the water
level in the steam generator falls and the cylinder is filled only with steam.
According to another construction, the regulating apparatus is arranged to
operate the throttle valve of the engine working the feed pump so as to vary the
supply of motive fluid to such engine according to the varying height of the water
level.
For this purpose the cylinder of the regulating apparatus is suitably fixed in
a slightly inclined position, as by bolting it sideways to the boiler, so that its
axis, or at or near its lower end, is at a height corresponding to about the height
of the normal water level in the boiler, its piston rod working through a stuffing
box at that end of the cylinder that is connected by pipes with the steam
and water spaces of the boiler. The piston rod is connected to a reciprocating
part of the pumping engine, and is connected to a piston having a hole through
its upper part as in the arrangement herein before described. At the other end
of the cylinder there is arranged another piston between the outer face of
which and the adjacent cylinder cover there is a spring encircling the piston
rod which extends through a stuffing box and is connected to the throttle valve
. of the engine driving the feed pump or a spring may be applied externally if
preferred to effect the same purpose. The controlling passage formed in the
wall of the cylinder and connected at one end to the pipe leading to the water
space of the boiler opens at its other end into a space which contains the cone
shaped controlling valve and communicates with the cylinder through two small
ports arranged one at each end of the second piston. The arrangement is such
that when the water enters the cylinder owing to the level in the boiler rising
and the first mentioned piston is moved towards the second one by the recipro-
cation of the part of the pump. to which its piston rod is attached, the water
between the two pistons will press back the second piston and cause its rod to
close the throttle valve of the engine and so stop the pump but on the entry of
steam into the cylinder, the second piston will be moved back by its spring, the
throttle valve of the pumping engine opened, and the supply of feed water re-
started. A safety valve is or may be fitted to the cylinder at a point between
the second piston and the adjacent end of the cylinder to prevent undue
pressure being set up in this part of the cylinder when the second piston is
moved outward. The regulating apparatus may be applied to a feed pump
worked by a main engine in which case instead of the second piston acting on
a steam throttle valve, it will, when the water level in the boiler attains the
normal act on a water valve so as to divert the further supply of feed water
from the boiler to a hot well or reservoir on the suction side of the pump.
If desired a pet cock may be fitted to the apparatus for draining the same
of water when required.
The reciprocating motion required for regulating apparatus of the kind herein
described, may be taken from the duplex feed pump, or from the donkey engine,
or from the main engine in connection with which it is applied.
1000

page_text: Improvements in Apparatus for Automatically Regulating the
Supply of Feed Water to Steam Boilers.
I, ERNEST LATHAM, of 3, Berlin Road, Catford Bridge, in the County of
Kent, 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:-
This invention has reference to apparatus whereby the working of a feed
pump for supplying feed water to a steam boiler can be controlled in an auto-
matic manner according to the height of the water in the said boiler.
According to one construction the working of the feed pump is controlled by
a piston that is connected to a suitable moving part of the pump and has a 'small
hole or passage formed therethrough, and is arranged to reciprocate in a cylinder
that is fixed in a horizontal or nearly horizontal position with its axis at or near
the normal water level in the boiler, is in communication at one side of the
piston with both the steam and water spaces of the boiler, and is provided with
a restricted connecting passage and a controlling valve therefor whereby the
two ends of the cylinder can be placed in communication with each other, the
arrangement is such that when the water level in the steam generator falls below
the normal, the cylinder will be filled with steam some of which passing through
the hole in the piston to the opposite side thereof, will place the piston nearly
in equilibrium and allow it and the pump to be worked at full speed, and when
the water rises in the boiler above the normal water level it will enter both ends
of the cylinder and impede the reciprocation of the piston therein and thereby
offer a resistance that will retard and ultimately stop the pump and consequently
the supply of feed water to the steam boiler.
Fig. 1 of the accompanying drawings illustrates in section one such arrange-
ment wherein 1 is the cylinder which is arranged in a position slightly inclined
to the horizontal and is attached to the steam boiler casing 2 at a height
corresponding to the normal water lever or nearly so, by a bracket 3, which may
be of cast iron and forms the cylinder cover, the other or outer end. of the
cylinder being provided with a stuffing box 4. 5 is the piston, the rod 6 of which
passes through the stuffing box 7 and is connected by a link 8 to one arm 9 of
a bell crank lever pivoted to an extension or projection 10 on the cylinder, the
other arm 9 of the lever being connected to a reciprocating part of a duplex
pump which is not shown. The piston 5 is formed near its upper part with a
small hole 11 that places the parts of the cylinder at opposite sides of the piston
in communication with each other. On the upper and lower sides of the cylinder
and near the inner end thereof are formed, hollow branches 12 and 13 to which
are secured pipes 14 and 15 which lead respectively to the steam space, and water
space of the steam boiler.
The pipe 15 is also in communication with the outer
end of the cylinder by means of a passage 16 of small cross section (hereinafter
called the controlling passage) which is shown, formed in the wall of the
cylinder and is adapted to be controlled by a cone-shaped valve 17 carried by a
rod that extends through a stuffing box 18 and is capable of being adjusted from
the exterior of the cylinder so as to regulate the effective cross sectional area
of the controlling passage.
The arrangement of the apparatus is such that when the water level in the
steam generator falls below the normal, the cylinder will become filled with
steam some of which will pass from one side of the piston to the other through
the small hole therein and so allow of the piston and pump being easily recipro-
cated and at full speed. When the level of the water in the boiler rises the

page_text: cylinder will be gradually filled and the action of the piston impeded, the water
at the inner end of the cylinder being easily forced back into the boiler through
the pipe 15 on the instroke of the piston but the water at the outer end, which
has to pass through the controlling passage 16 or the hole 11 which will offer
considerable resistance to the outward movement of the water and consequently
to the piston and thus automatically stop the pump, which, however, will auto-
matically restart as soon as the water level in the steam generator falls and the
cylinder is filled only with steam.
According to another construction, the regulating apparatus is arranged to
operate the throttle valve of the engine working the feed pump so as to vary the
supply of motive fluid to such engine according to the varying height of the
water level.
Fig. 2 illustrates in section an arrangement for this purpose. The cylinder is
suitably fixed in a slightly inclined position, as by bolting it sideways to the boiler,
so that its axis, at or near its lower end, is at a height corresponding to about
the height of the normal water level in the boiler; the piston rod 6 works
through a stuffing box 7 at that end of the cylinder that is connected by the
pipes 14 and 15 with the steam and water spaces of the boiler. The piston rod 6
is connected to a reciprocating part of the pumping engine, and is connected to
a piston having a hole through its upper part as in the arrangement herein-
before described. At the other end of the cylinder there is arranged another
piston 20 between the outer face of which and the adjacent cylinder cover 21
there is a spring 22 encircling the piston rod 23 which extends through a stuffing
box 24 and is connected to the throttle valve of the engine driving the feed
pump or the spring 22 may be applied externally, if preferred, to effect the
same purpose. The controlling passage 16 formed in the wall of the cylinder and
connected at one end to the pipe 15 leading to the water space of the boiler opens,
at its other end, into a space 25 which contains the cone-shaped controlling
valve 17 and communicates with the cylinder through two small ports 26, 26
arranged one at each end of the piston 20. The arrangement is such that wlien
the level in the boiler rises and water enters the cylinder, the piston 5 is moved
towards the piston 20 by the reciprocation of the part of the pump to which its
piston rod is attached, the water between the two pistons, owing to its incom-
pressibility and to. the quantity displaced by the piston 5 in a given period, not
being able to escape through the port 26 in an equal period, communicates
motion to the piston 20 and causes its rod to close the throttle valve of the
engine and so stop the pump; but, on the entry of steam into the cylinder through
the various pipes and passages the piston 20 will be moved back by its spring 22,
the throttle valve of the pumping engine opened, and the supply of feed water
restarted.
A safety or relief valve is or may be fitted to the cylinder at a point between
the piston and the adjacent end of the cylinder to prevent undue pressure being
set up in this part of the cylinder when the said piston is moved outward.
If desired a pet cock may be fitted to the apparatus for draining the same of
water when required.
The regulating apparatus may be applied to a feed pump worked by a main
engine in which case, instead of the piston 20 acting on a steam throttle valve,
it will, when the water level in the boiler attains the normal, act on a water
valve so as to divert the further supply of feed water from the boiler to a hot
well or reservoir on the suction 'side of the pump.
Figs. 3 and 4 show in elevation and in central section respectively a modifica-
tion of the arrangement described with reference to Fig. 2;
Fig. 5 is a cross section on the line A-A Fig. 3.
In this case, the piston 20 acts as a valve and controls the passage of steam
to the pump; the cylinder 1 has fixed at about the middle of its length a diaphragm
23 formed with valve openings 24; 25 is a valve arranged in the outer face of the
diaphragm. The piston 5 is also formed with valve openings 26 and is fitted with

page_text: a freely working valve 27. The cylinder 1 is surrounded by a casing 28 between
which and the cylinder 1 the passage 16 is formed, a port 16 being formed in
the cylinder 1 which is controlled by a valve 17. The casing 28 is formed with
a branch 15 which is connected with the water space of the boiler and with a
branch 29 that is connected with a steam supply and is in communication with
the outer end portion of the cylinder 1 through a passage 30 and ports 30 and 30b.
15, 15b are ports leading to the inner end of the cylinder 1 from the
branch 15. 31 is an outlet for steam from the cylinder 1 to a self-starting
pump. The spring 22 is arranged between a fixed stirrup piece 32 and a
collar 33 on the piston rod 23. In this arrangement, on the level of the water
in the boiler rising above the normal the piston 5 acts like the bucket of a
pump, the water after passing through it being forced by it through the
diaphragm 23; it accumulates within the cylinder between the diaphragm
and the piston 20 as the port 16ª is not large enough to allow of its
ready escape and forces the piston 20 back in opposition to its spring 22 until
it covers the port 31 and thus cuts off the steam supply to the feed pump, which
thereupon stops. On the water level again falling the accumulated water_be-
tween the diaphragm 23 and the piston 20 is slowly discharged through the
port 16, until the port 31 is again opened whereupon steam will again pass to
the pump, which will automatically restart.
The arrangement just described may be employed to control a main engine
pump or a constantly running donkey, the piston rod 23 being then arranged to
actuate an external water diverting valve and the outlet 31 for steam from the
cylinder 1 being closed or dispensed with.
The reciprocating motion required for regulating apparatus of the kind herein
described, may be taken from the duplex feed pump, or from the donkey engine,
or from the main engine in connection with which it is applied.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is:-
1. Apparatus for automatically regulating the supply of feed water to steam
boilers, wherein the action of a feed pump is controlled by a piston reciprocated
within a cylinder, the said cylinder being arranged at or about the normal level
of the water in the boiler, and the arrangement being such that if the water
level in the boiler rise the cylinder will become charged with water and the move-
ment of the piston and of the feed pump. retarded, whilst on the water level
falling, the cylinder will become charged with steam and the piston will be
comparatively free to reciprocate, substantially as described.
2. Apparatus for automatically regulating the supply of feed water to steam
boilers, wherein the action of a feed pump is controlled by a piston reciprocated
within a cylinder, the said cylinder being arranged at or about the normal level
of the water in the boiler, and the motion of the said piston in one direction
being communicated to a supplementary piston upon water being caused to
accumulate between the two pistons by a rise of water level in the boiler so as
to close in opposition to a spring the feed pump motive fluid supply valve con-
nected to the supplementary piston, whilst, when only steam is between the two
pistons which will occur when the water level falls, the supplementary piston
and the valve connected to it will be actuated by the spring so as to open the
latter, substantially as described.
3. Apparatus for automatically regulating the supply of feed water to steam
boilers, wherein the action of a feed pump is controlled by a piston reciprocated
within a cylinder, the said cylinder being arranged at or about the normal level
of the water in the boiler, and the motion of the said piston in one direction
being communicated to a supplementary piston upon water being caused to
accumulate between the two pistons by a rise of water level in the boiler so
as to operate, in opposition to a spring, a valve connected to the supplementary

page_text: piston whereby the further discharge of water by the feed pump will be diverted
from the boiler, whilst, when only steam is between the two pistons, which
will occur when the water level in the boiler falls, the supplementary piston and
the valve connected to it will be actuated by the spring so as to allow the feed
water to pass to the boiler, substantially as described.
4. Apparatus for automatically regulating the supply of feed water to steam
boilers constructed, arranged, and operating substantially as described with
reference to and shown in Fig. 1; in Fig. 2, or in Figs. 3 to 5 of the accom-
panying drawings.