Improvements in or relating to the Automatic Water Supply of Steam Generators.
Year: 1896

page_text: Date of Application, 4th Nov., 1896
Complete Specification Left, 3rd Sept., 1897-Accepted, 16th Oct., 1897
PROVISIONAL SPECIFICATION.
Improvements in or relating to the Automatic Water Supply of
Steam Generators.
We, THOMAS CLARKSON of Grove Villa, Carshalton Grove Sutton, in the County
of Surrey, Engineer, and HERBERT CHURCHILL CAPEL, of 168 Dalston Lane, in
the County of Middlesex, Engineer, do hereby declare the nature of this invention
to be as follows:-
This invention relates to the automatic supply of feed water to steam generators
of various kinds, but we will describe it as applied to small steam generators
suitable for self-propelled vehicles.
The object of the invention is to automatically control the supply so that it
may vary according to the demands on the boiler, a point which is of special
importance with boilers of small water capacity, where steam is rapidly generated,
as in boilers required for self-propelled vehicles, fire engines and the like.
In carrying out the invention we may operate by any pump or injector driven
by steam from the boiler to be supplied, but in many cases we prefer to utilise
the power of the engine supplied by the boiler to operate a pump, which will
be in operation during the whole of the time that the engine is running, whether
it be delivering water to the boiler or not. The pump will draw from any
suitable reservoir or source of supply, and is controlled by a device which may
either take the form of a float, an expansion tube of dissimilar metals or other
equivalent device. The controlling device, may control either the suction valve
or the delivery valve; in the latter case the. valve will be arranged to act as a
deflector, so that the water pumped would be delivered either back to the supply
or into the boiler-a non-return valve being preferably employed so that when
the pump delivered back to the supply, it would not have to force the water
against the boiler pressure.
In controlling the suction or foot valve the intention is that the supply should
be so arranged that the pump will always be supplied with water so as to prevent
the access of air, which would interfere with the working of the pump when
feeding the boiler. A convenient and suitable way of applying the control is
to utilise two fingers or equivalent devices, so arranged that when it is required
to supply the boiler, their working faces come into contact, and thus open or
close, as the case may be, the valve, one of the fingers being directly or indirectly
connected with the valve and the other with a working part of the pump.
above arrangements may be reversed, the contact or non-contact of the parts then
operating in the manner opposite to that above described. The arrangement may
be such that instead of controlling a whole stroke of the pump the supply may
be stopped at a portion of the stroke, and if necessary more than one finger or
pairs of fingers or equivalent may be employed for this purpose. With such an
arrangement the operation of the valve, whether to cause or cease the supply,
may be actually effected by the pump itself, which thus would provide all the

page_text: power necessary leaving to the float merely the light duty of placing the finger
into or out of contact, or otherwise make or break the connection.
In the case of boilers constructed in, sections of tubes or elements which are
fed with water at their lower ends and deliver steam at their upper or opposite
ends, into the steam drum or reservoir of the boiler it is convenient to use a
thermometer working either by the expansion of metals or the expansion of metals
and liquids, according to the temperature of the steam or steam and water, which
is delivered by the generating tubes into the steam drum. When the supply
of water to the generating tubes is insufficient the steam coming from them
would be super-heated, thus causing the thermometer to start a supply of feed
water which would continue until the temperature of the steam delivered by
the tubes was reduced, and the thermometer would then reduce or entirely stop
a further supply by controlling the operation of the pump, as previously explained.
The pressure from the thermometer may operate upon one side of a flexible
diaphragm, the motion of which is transmitted..to the controlling, mechanism
from the other side by a spring bar, or rod, adapted to be compressed between
the diaphragm and a fixed but preferably adjustable point, so that as the
diaphragm moves, the spring becomes bowed or arched, the movement being
preferably taken from the centre where it would be greatest so as to operate the
controlling valve or other mechanism.
1
The thermometer may take the form of a long tube passing through a stuffing
box into the interior of the boiler or steam pipe, so that the adjustment may
be easily varied to suit the desired working of the engine, by placing more or
less of the tube into the chamber, the variations in the temperature of which
cause the operation.
:
Another means of regulating the supply of feed water consists in having con-
nected to the boiler a separate vessel or drum, the upper part of which
communicated with the steam space of the boiler, and the lower with the water
space, for which latter connection a relatively large tube is preferable to allow
of the free action of the water. This drum is supplied direct with feed water
from the feed pump, the water rising in the drum to about the normal water level
of the boiler. Within the drum is a smaller vessel or chamber situated pre-
ferably at a higher level than the water inlet, and at or about the normal water
level of the boiler. This vessel is only partly filled with water leaving a partial
vacuum in the other part, and communicates by a tube with a flexible diaphragm
and connections similar to those previously described. Below a temperature of
212° F there will be practically no pressure in the small vessel, but above that
temperature the steam will collect and increase the pressure and thus cause the
water in the tube to act upon the diaphragm, and so operate the controlling
mechanism. Should the water in the drum fall to too low a level a greater
portion of the inner vessel will be exposed to the heat of the steam, and con-
sequently the temperature in the vessel will be quickly raised, thus admitting
a further supply of water, which will rise in the drum and in the boiler to the
requisite level, and in doing so will again reduce the temperature of the inner
vessel to the normal, thus closing the pump valve or otherwise stopping the supply
of water. It is to be noted that it would not be desirable to fill the inner vessel
entirely full of water because there would then be no means of controlling the
pressure exerted by the expansion of the water due to the heat of the steam upon
the outside of this vessel, and explosion of some part would almost certainly
result. By leaving a portion of the vessel empty all danger of such excessive
pressure is avoided, since the pressure in the vessel corresponds only to the
temperature inside it, which is, for practical purposes, identical with that of the
temperature in the drum and therefore is known and can be easily regulated.
Where a float is used or other device requiring the passage of a rod or equivalent
through the stuffing box in the boiler, a movement different from that due to
the float or other operating device may be imparted to this rod or equivalent,
in order to prevent sticking. Thus if the movement imparted by the float to

page_text: the rod be a rotary or partially rotary movement we may, by other mechanism
independent of the float, impart a constant or intermittent reciprocating move-
ment; or should the movement imparted by the float be reciprocating, we may
impart a partial or complete rotary movement.
Dated this 4th day of November 1896
BOULT & WADE,
Agents for the. Applicants
Improvements in or relating to the Automatic Water Supply of
Steam Generators.
We, THOMAS CLARKSON of Grove Villa, Carshalton Grove Sutton in the County
of Surrey, Engineer, and HERBERT CHURCHILL CAPEL of 168 Dalston Lane, .in
the County of Middlesex, 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 relates to the automatic supply of feed water to steam generators
of various kinds, but we will describe it as applied to small steam generators
suitable for self-propelled vehicles.
The object of the invention is to automatically control the supply so that it
may vary according to the demands on the boiler, à point which is of special
importance with boilers of small water capacity, where steam is rapidly generated,
as in boilers required for self propelled vehicles, fire-engines and the like.
In carrying out the invention we may operate by any pump or injector driven
by steam from the boiler to be supplied, but in many cases we prefer to utilize
the power of the engine supplied by the boiler to operate a pump, which will
be in operation during the whole of the time that the engine is running, whether
it be delivering water to the boiler or not. The pump will draw from any
suitable reservoir or source of supply, and is controlled by a device which may
either take the form of a float, an expansion tube of dissimilar metals or other
equivalent device. The controlling device may control either the suction valve
or the delivery valve; in the latter case the valve will be arranged to act as a
deflector, so that the water pumped would be delivered either back to the supply
or into the boiler-a non-return valve being preferably employed so that when
the pump delivered back to the supply, it would not have to force the water
against the boiler pressure.
In controlling the suction or foot valve the intention is that the supply should
be so arranged that the pump will always be supplied with water so as to prevent
the access of air, which would interfere with the working of the pump when
feeding the boiler. A convenient and suitable way of applying the control is
to utilize two fingers or equivalent devices, so arranged that when it is required
to supply the boiler, their working faces come into contact, and thus open or
close, as the case may be, the valve, one of the fingers being directly or indirectly
connected with the valve and the other with a working part of the pump.
above arrangement may be reversed, the contact or non-contact of the parts then
With such an
operating in the manner opposite to that above described.
arrangement the operation of the valve, whether to cause or cease the supply,
may be actually effected by the pump itself, which thus would provide all the
The

page_text: power necessary leaving to the float merely the light duty of placing the finger
into or out of contact, or otherwise make or break the connection.
In the case of boilers constructed in sections of tubes or elements which are
fed with water at their lower ends and deliver steam at their upper or opposite
ends, into the steam drum or reservoir of the boiler it is convenient to use a
thermometer working either by the expansion of metals or the expansion of metals
and liquids, according to the temperature of the steam or steam and water, which
is delivered by the generating tubes into the steam drum. When the supply
of water to the generating tubes is insufficient the steam coming from them
would be super-heated, thus causing the thermometer to start a supply of feed
water which would continue until the temperature of the steam delivered by
the tubes was reduced, and the thermometer would then reduce or entirely stop
a further supply by controlling the operation of the pump, as previously explained.
The pressure from the thermometer may operate upon one side of a flexible
diaphragm, the motion of which is transmitted to the controlling mechanism
from the other side by a spring bar or rod, adapted to be compressed between
the diaphragm and a fixed but preferably adjustable point, so that as the
diaphragm moves, the spring becomes bowed or arched, the movement being
preferably taken from the centre where it would be greatest so as to operate the
controlling valve or other mechanism.
The thermometer may take the form of a long tube passing through a stuffing
box into the interior of the boiler or steam pipe, so that the adjustment may
be easily varied to suit the desired working of the engine, by placing more or
less of the tube into the chamber, the variations in the temperature of which
cause the operation.
Another means of regulating the supply of feed water consists in having con-
nected to the boiler a separate vessel or drum, the upper part of which
communicates with the steam space of the boiler, and the lower with the water
space for which latter connection a relatively large tube is preferable to allow
of the free action of the water. This drum is supplied direct with feed water
from the feed pump, the water rising in the drum to about the normal water level
of the boiler. Within the drum is a smaller vessel or chamber situated pre-
ferably at a higher level than the water inlet, and at or about the normal water
level of the boiler. This vessel is only partly filled with water leaving a partial
vacuum in the other part, and communicates by a tube with a flexible diaphragm
and connections similar to those previously described. Below a temperature of
2120 F there will be practically no pressure in the small vessel but above that
temperature the steam will collect and increase the pressure and thus cause the
water in the tube to act upon the diaphragm, and so operate the controlling
mechanism. Should the water in the drum fall to too low a level a greater
portion of the inner vessel will be exposed to the heat of the steam, and con-
sequently the temperature in the vessel will be quickly raised, thus admitting
a further supply of water, which will rise in the drum and in the boiler to the
requisite level, and in doing so will again reduce the temperature of the inner
vessel to the normal, thus closing the pump valve or otherwise stopping the supply
of water. It is to be noted that it would not be desirable to fill the inner vessel
entirely full of water because there would then be no means of controlling the
pressure exerted by the expansion of the water due to the heat of the steam upon
the outside of this vessel, and explosion of some part would almost certainly
result. By leaving a portion of the vessel empty all danger of such excessive
pressure is avoided, since the pressure in the vessel corresponds only to the
temperature inside it, which is, for practical purposes, identical with that of the
temperature in the drum and therefore is known and can be easily regulated.
Where a float is used or other device requiring the passage of a rod or equivalent
through the stuffing box in the boiler, a movement different from that due to
the float or other operating device may be imparted to this rod or equivalent,
in order to prevent sticking. Thus if the movement imparted by the float to

page_text: the rod be a rotary or partially rotary movement we may, by other mechanism
independent of the float, impart a constant or intermittent reciprocating move-
ment; or should the movement imparted by the float be reciprocating, we may
impart a partial or complete rotary movement.
In the accompanying drawings
Figure 1 is a sectional elevation of a steam generator fitted with one form of
the improved apparatus.
Figure 2 is a sectional plan of the same.
Figure 3 is a sectional plan of the steam drum of a water tube boiler showing
a modification.
Figure 4 is a section on the line 4-4 of Figure 3.
Figure 5 is a diagrammatic sectional elevation of another form of the apparatus.
Figure 6 is a similar view of yet another arrangement.
Like letters indicate like parts throughout the drawings.
The steam drum of the boiler, which is of the water tube type, is composed
of a cylindrical casing A with end plates A1 and A2. A rod B runs through the
steam drum from end to end having a bearing in the plate A¹ in a small cup A³,
screwed into the plate A. The rod B passes out from the plate A through a
stuffing box A provided with a gland A. A tubular float C is carried upon
the ends of levers B attached to the rod B, the opposite ends of these levers
supporting a counterpoise bar C. The position of the rod B is so arranged within
the steam drum that the rise and fall of the water will impart rotary motion, to
the rod by means of the float.
Upon the end of the rod B, which projects from the stuffing box A, is mounted
a lever B2 which is connected by a rod B3 with a frame D. This frame is cou-
veniently rectangular in shape and mounted in bearings D' so that it may be
readily turned by the movement of the float in the steam drum. A light rod E
is carried in the frame D), its ends passing through the end portions of the frame
in such a manner that the rod may be easily slid to and fro parallel to the axis
about which the frame D turns. The rod E carries projecting fingers E E
which are preferably arranged in different planes as shown in Fig. 1. The
plunger F of the pump carries upon it a finger F1 which is curved as shown in
Fig. 1 or arranged so as to reciprocate in a plane parallel to the axis of the frame 1)
and between those planes in which the fingers EE lie and can be moved. To
one end of the rod E which projects beyond the end piece of the frame D is
pivotted one end of a lever G whose fulcrum is at G₁ on the frame D, and to
whose other end is pivotted a rod G2 which communicates with a valve H. The
operation of the device is as follows:--
Supposing the pump, which is continually working, is forcing water into
the boiler, the float C will rise and by this movement will turn the frame D
upon its pivots D' and so bring the finger Ez into the plane in which the finger F
on the pump plunger is reciprocating. Upon the finger striking the finger E,
the rod E will be moved endwise and thus through the lever G and connecting
rod G2 the valve H will be operated so as to turn off the water from flowing into
the boiler. As soon as the water in the boiler falls sufficiently the falling of the
float therewith will move the frame D so as to bring the finger E' in the path of
the finger F1, the latter by contact with the finger E moving the rod E and
again operating the valve H so as to allow water to pass once more into the boiler.
In a modification of this arrangement shown in Figs. 3 and 4, the end of the
rod B instead of passing through the end plate of the steam drum, terminates
within the latter and carries upon its end a screw-threaded plug B', the end
of which is reduced as at B³ to form a valve. The plug B screws into the valve
casing A6 in which is a valve seat A', the whole being carried upon the end of a
short tube A8, which is bolted to the side of the steam drum A where it com-
municates with a steam operated pump. The chamber A opens through a short
pipe A10 into the steam space in the drum, the pipe A leading to the highest

page_text: point of the steam drum in order to prevent priming. The operation of this
arrangement is as follows:-
Upon the level of the water in the steam drum rising, the float C is raised and
the rod B turned, this rotation by reason of the screw threaded plug B4 bringing
the valve B5 down on its seat A and thus cutting off or reducing the steam' supply
to the pump. As soon as the level of the water falls the rotation of the rod B
by the falling of the float C opens the valve B and admits more steam to the
pump. In this arrangement the cup or bearing piece A³ is arranged so as to
allow a slight endwise movement of the rod B.
In order to prevent, in the first above described device the rod 13 from seizing
or otherwise sticking in the stuffing box A', it may have imparted to it a slight
endwise to and fro movement obtained from the pump or other moving part of
the engine as found convenient.
Another device for regulating the water supply is illustrated in Fig. 5, where
it is shown applied to a single element of a water tube boiler composed of
horizontal tubes J J¹, and connecting tubes J. The water enters the element
at J3, the steam issuing at J. Into the tube J at the opposite end to the steam
exit J is introduced a tube K, hereinafter called the thermometer tube, which is
preferably constructed of metal so as to withstand a considerable pressure. This
tube is in communication through a tube K¹ with a space K2 at the back of a
diaphragm L in a regulator M. The latter consists of a casing which contains
a spring bar M with bevelled ends which are carried in an adjustable plug M
and a loose fitting piston or block M³ which lies against the diaphragm L.
Pressure in the space K3 at the back of the diaphragm L causes the latter to move
and bend the bar M this movement being taken off at or about the centre of
the bar by a rod M connected to a valve H.
The thermometer tube K, tube K' and space K³ are hermetically sealed and
contain water which all but fills them, a small space being left which is practically
a vacuum being only occupied by water vapour. The action of this arrangement
is as follows: The spring bar M' is adjusted to deflect when the pressure per
square inch on the diaphragm L exceeds by a predetermined amount the working
pressure in the boiler. So long as the steam in the collecting tube J is saturated
the pressure within the thermometer tube K is the same as that in the tube J,
but as soon as the steam in the tube J becomes superheated the pressure within
the tube K is increased and consequently the bar is deflected & the valve H
operated so as to supply water to the boiler. By leaving a small vacuum space
in the tubes K and K the pressure of the water vapour is employed and not
the actual expansion of the water only.
Another
In the last described arrangement the controlling of the pump is shown to
take place by the action of the regulator M upon the valve H, controlling either
the steam supply to the pump or the water supply to the boiler.
arrangement for controlling the water supply when the pump is continually
operating is shown in Fig. 6. The boiler JJJ is provided in the steam tube
or drum J with a thermometer tube K which is in communication, as before,
by a tube 'K' with the space behind the diaphragm in the regulator M. The
latter is provided on its casing with two bosses M and M, into the former being
screwed a tube N leading from the water supply, while into the boss M, is
screwed a plug O which forms a connection to the pump P. The plug O is
provided with a central hole O, in which can freely slide a wire needle Q the
lower end of which rests in contact with the upper surface of the regulator
'bar M, the latter in this case being arranged to be deflected downwards. The
plug O is also bored with a series of converging holes 02 which open above into
a small chamber 03 round the upper end of the wire Q. The upper part of the
chamber 03 forms a seating for a ball valve R, the relation of this valve to the
needle and the regulator bar M' being such that so long as the bar Mremains
undeflected, that is to say, so. long as there is sufficient water in the boiler, the

page_text: upper end of the needle Q will hold the ball valve R off its seating. The pump
plunger P is preferable arranged directly over the valve R, the passage P3
leading from the pump to the boiler being provided with a delivery valve S.
The operation of the device is as follows:-
Water enters by the pipe N and has free access to the interior of the casing
of the regulator I, thence, the pump being continually in action, it is sucked
past the valve R, but while the latter is held off its seat, so long as there is
sufficient water in the boiler, the water sucked in by the pump plunger P is
returned into the casing of the regulator and so into the water receptacle in
place of being forced into the boiler. As soon however as the boiler requires
water, by means of the thermometer tube K in the manner previously described,
the bar M is deflected, and the ball valve R allowed to fall on its seat, each
stroke of the pump now forcing water through the valve S into the boiler.
In order to prevent the ball valve S from jamming in the upper part of its
casing, the entrance P³ of the pipe leading to the boiler is not formed conical
but angular so as to leave passages around the ball when it is forced against
the end of the tube.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
1. Controlling the supply of water to a steam generator by the rise and fall
of a float within the generator introducing projections into the path of a finger
upon a reciprocating part of the pump so as at such times to operate a controlling
valve substantially as described and illustrated in Figures 1 and 2 of the accom-
panying drawings.
2. The combination with a pump carrying a reciprocating finger such as F
of a pivotted frame carrying projections such as E1 E2 controlling the water supply
valve and adapted to be introduced into the path of the reciprocating finger
substantially as and for the purpose described.
3. The combination with a steam generator of a pivotted frame carrying a
device for controlling the water supply valve and a float within the steam
generator the movement of which imparts movement to the frame for the purpose
described.
4. In an apparatus for automatically controlling the supply of water to a steam
generator the employment of a pivotied frame such as D operated by a float in
the generator substantially as described.
5. In a steam generator a float-controlled screw valve such as B for governing
the action of a steam pump substantially as described.
6. Regulating the water supply of a steam generator by the bending of a spring
bar such as M when subjected to an excess of end pressure.
7. In a steam generator the combination with a spring bar such as M' of a
diaphragm L exposed on one side to pressure from the contents of a thermometer
tube such as K for the purpose described.
8. In a steam generator the combination with a spring bar such as M¹ of a
controlling device for the suction or delivery valve of a pump.
9. In a steam generator the combination with a thermometer tube such as K
of a water supply regulator adapted to be put in operation by variations in the
degree of superheat of the steam delivered.
10. In an apparatus for automatically controlling the supply of water to a
steam generator the combination with the suction valve of the pump which feeds
the generator of a needle and spring bar such as Q and M and diaphragm L
substantially as and for the purpose described and illustrated in Figure 6 of the
accompanying drawings.
11. The combination and arrangement of parts constituting the complete
apparatus for automatically controlling the supply of water to a steam generator

page_text: substantially as described and illustrated in Figures 1 and 2 or Figures 3 and 4
or Figure 5 or Figure 6 of the accompanying drawings.
Dated this 1st day of September 1897.
T. CLARKSON.
Boult & Wade,
Agents for the Applicants.