Improvements in Centrifugal Pumps.
Year: 1899

page_text: Date of Application, 29th Apr., 1899
Complete Specification Left 20th Jan 1900-Accepted. 31st Mar.. 1900
PROVISIONAL SPECIFICATION.
Improvements in Centrifugal Pumps.
I, HENRI ANTOINE THIRION, of 160, Rue de Vaugirard, Paris, France, Engineer,
do hereby declare the nature of this invention to be as follows:-
Centrifugal pumps will not suck when a certain proportion of air is drawn in
and can only be primed again after expelling this air. Experience has shewn
that the air which accumulates in a pump remains compressed so long as the
pump works at its normal speed or even at a very reduced speed if the water
in the delivery pipe continues to exert its pressure on the pump and that if
the pressure in the delivery pipe, that is to say the pressure due to the head of
water above the pump, be destroyed the re-priming of the pump may be easily
effected by expelling the air which caused the interruption of the working. In
order therefore to re-prime a centrifugal pump without arresting its operation
it is necessary.
(1) to cut off the pressure above the pump;
(2) to discharge the air accumulated;
(3) to re-introduce water into the pump as when priming it at starting.
The present improvements in centrifugal pumps consist in the application
thereto of the method of re-priming above specified. I have also found that in
centrifugal pumps the action of the pump produces a whirling motion tending
to separate from the water the air which may be in suspension therein which
air, owing to its lesser density to that of the water, accumulates at the axis of
rotation of the pump and may even unprime it. In order to obviate this ob-
jection, according to this invention it is proposed to apply at the connection of
the suction pipe with the pump a device which consists of fixed radial blades for
receiving the thrust of the water and at same time deflect it into the pump and
prevent the centrifugal action of the latter being exerted only on the centre of
the column of liquid. In this manner the water arriving by the suction pipe will
be subjected to the centrifugal action of the pump only at its moment of entry
therein.
These improvements are illustrated by way of example in the accompanying
drawings wherein Figure 1 shews a pump provided with a hand-operated re-
priming device. Figure 2 shews a pump provided with an automatic re-priming
arrangement. Figure 3 is a modification of this latter arrangement. Figure 4
is an underside plan of the winged anti-whirling device applied to the pump
represented in Figure 3. Figure 5 shews a pump provided with an electrically
operated re-priming device. The same letters of reference denote like parts in all
the figures.
In Figure 1 the pump is provided with:-
(1) A non-return valve A placed upon the delivery pipe at a point as near the
pump as possible;
(2) A discharge cock B below the valve, open to the atmosphere;
(3) A pipe C for connecting, when cock D is open, the delivery pipe above
volvo with the suction nine below the Dumn

page_text: The cocks B and D) may be both mounted upon the same spindle so as to
be operated by a single handle as shewn.
When the pump becomes unprimed the non-return valve A closes on its seat
and thus relieves the pump of the pressure of the delivery column and foot
valve also closes since the upward flow has ceased. By then operating the
cocks BD the water is returned through pipe C from the delivery pipe to the
suction pipe below the pump and the air which is confined in the pump is
expelled through purge cock B so that the pump becomes re-primed whereupon
the cocks B. D are closed.
The valve A may be replaced by a cock or stop valve of any suitable kind
operated by hand or automatically. The water for re-priming may also be
taken from a reservoir giving a head of water above the pump, more particularly
in cases where the capacity of the delivery pipe above the valve A is insufficient
to contain the quantity of water necessary for re-priming the pipe for supply-
ing the water from said reservoir being branched on to any suitable point of the
suction pipe, between the pump and the foot valve E.
Figure 2 represents an arrangement for effecting the re-priming automatically,
in which the valve A, in closing on its seat when the pump becomes unprimed
opens the two valves B¹, D', which replace the cocks B D of Figure 1 whereby
the re-priming of the pump is effected automatically as before.
Figure 3 represents a modification of the automatic re-priming arrangement
in which the valves B D are no longer controlled directly by the valve A but
are opened when the pump becomes unprimed by the pressure of the water in
the delivery pipe acting on a piston H fast on the spindle of said valves. For
this purpose the valve A in closing on its seat raises an auxiliary valve F so as
to permit of water from the delivery pipe passing through pipe G
and acting on the under face of piston H so as to raise both valves B',
]), the valve B₁ putting the pump in communication with the atmosphere
through pipe I so as to permit the escape of the accumulated air therefrom and
the valve D permitting the return of the water from the delivery pipe through
Pipe C to the suction pipe.
When by the accumulation of a certain quantity within the pump the latter
has become unprimed the valve A closes on its seat and raises the auxiliary
valve F' so as to allow the water from the delivery pipe to pass through the pipe G
and raise piston H and with it the two valves B, D, so as to permit the escape
of the accumulated air through valve 13 and the return of water from the
delivery pipe to the suction pipe so as to re-prime the pump. When the pump has
thus been re-primed the water which it delivers raises valve A and closes the
auxiliary valve F whereupon pipe G is opened to the atmosphere by a piston J
on the spindle of valve F uncovering outlet K and thus allowing the water
beneath the piston H to escape and the piston to descend to its lowest position
by its own weight or by the stress of a spring counterweight or otherwise,
together with the two valves B', D', which close on their seats and respectively
shut off all communication between the interior of the pump and the atmosphere
and between the delivery and suction pipes.
The re-priming may also be effected by electrical means. as many centrifugal
pumps are actuated by dynamos.
Figure 5 shews a centrifugal pump in which the two valves B', D', are
electrically operated. The said valves are both mounted upon the same lever L
which is jointed to a soft iron core M influenced by a solenoid N. When the
pump becomes unprimed, owing to the dynamo having less work to do, a portion
of the current traverses the solenoid, the core M becomes attracted, and both
valves B. D', are opened. When the pump is immersed the foot valve E. pipe C
leading to the suction, cock D, or valve D', would not be required as in this case,
in the event of air entering the pump when the sump is pumped dry and un-
priming it, the water necessary for re-priming would naturally enter the pump
on the rising of the water level but the valve A is always indispensable as well

page_text: as cock B or valve B' for enabling the discharge of the air which determines the
re-priming.
The centrifugal action of the pump produces a whirling motion at the centre
of the column of liquid supplied by the suction pipe which impedes the priming
of the pump and in order to remedy this defect there is applied to the inner end
of the suction pipe an anti-whirling device 0 provided with fixed radiating
blades of straight or curved form so disposed as to direct the water into the
pump as shewn in Figures 3 and 4. This device also has the further advantage
of preventing the momentum of the water raised from acting upon the pump.
The re-priming arrangements and anti-whirling device herein described may be
applied either together or separately to all kinds of centrifugal pumps whether
horizontal or vertical and whether having one or two inlets.
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.
Improvements in Centrifugal Pumps.
1. HENRI ANTOINE THIRION, of 160, Rue de Vaugirard, Paris, France, 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:-
Centrifugal pumps will not suck when a certain proportion of air is drawn in
and can only be primed again after expelling this air. Experience has shewn
that the air which accumulates in a pump remains compressed so long as the
pump works at its normal speed or even at a very reduced speed if the water
in the delivery pipe continues to exert its pressure on the pump and that if
the pressure in the delivery pipe, that is to say the pressure due to the head of
water above the pump, be destroved the re-priming of the pump may be easily
effected by expelling the air which caused the interruption of the working. In
order therefore to re-prime a centrifugal pump without arresting its operation
it is necessary.
(1) to cut off the pressure above the pump;
(2) to discharge the air accumulated;
(3) to re-introduce water into the pump as when priming it at starting.
The present improvements in centrifugal pumps consists in the application
thereto of the method of re-priming above specified. I have also found that in
centrifugal pumps the action of the pump produces a whirling motion tending
to separate from the water any air which may be in suspension therein which
air, owing to its density being less than that of the water, accumulates at the
axis of rotation of the pump and may even unprime it. In order to obviate this
objection, according to this invention it is proposed to apply at the connection of
the suction pipe with the pump a device which consists of fixed radial blades so
arranged as to receive the thrust of the water and at same time deflect it into the
pump and prevent the centrifugal action of the latter being exerted on the centre
of the column of liquid. In this manner the water arriving by the suction pipe
will be subjected to the centrifugal action of the pump only at its moment of
entry therein.
These improvements are illustrated by way of example in the accompanying
drawings wherein Figure 1 shews a pump provided with a hand-operated

page_text: repriming device and Figure 2 shews a pump provided with a re-priming apparatus
automatically controlled by the delivery valve. Figure 3 shews the same arrange-
ment of re-priming apparatus controlled by the suction valve. Figure 4 repie-
sents a modification in which the valves open under the action of the delivery-
column through the medium of a piston and auxiliary valves controlled by the
valve on the delivery pipe. Figure 5 is an underside plan of the winged anti-
whirling device applied to the pump represented in Figure 4. Figure 6 shew;
the same aangement of re-priming apparatus as in Figure 4. but controlled
by the non-return suction valve. Figure 7 shews another arrangement in which
the wa'er for re-priming is supplied from a reservoir. Figure 8 shows a pump
provided with an electrically operated re-priming device. Figures 9 and 10
shew two of the preceding arrangements of apparatus as electrically operated.
The same letters of reference denote like, parts in all the figures..
In Figure 1 the pump is provided with:-
(1) A non-return valve A placed upon the delivery pipe at a point as near the
pump as possible;
(2) A discharge cock B below the valve, open to the atmosphere;
(3) A pipe C for connecting, when cock D is open the delivery pipe above
valve A with the suction pipe below the pump.
The cocks B and D) may be both mounted upon the same spindle so as to
be operated by a single handle as shewn.
When the pump becomes unprimed the non-return valve A closes on its seat
and thus relieves the pump of the pressure of the delivery column and the foot
valve E also closes since the upward flow has ceased. By then operating the
cocks B D the water is returned through pipe.C from the delivery pipe to the
suction pipe below the pump and the air which is confined in the pump is
expelled through the discharge cock B so that the pump becomes re-primed
whereupon the cocks B D are closed.
The valve A may be replaced by a cock or stop valve of any suitable kind
operated by hand or automatically. The water for re-priming may also be
taken from a reservoir giving a head of water above the pump, more particularly
in cases where the capacity of the delivery pipe above the valve A is insufficient
to contain the quantity of water necessary for re-priming the pipe for supply-
ing the water from said reservoir being branched on to any suitable point of the
suction pipe, between the pump and the foot valve E.
Figure 2 represents an arrangement for effecting the re-priming automatically.
in which the valve A, in closing its seat when the pump becomes unprimed
opens the two valves B', D', which replace the cocks B D of Figure 1 whereby
the re-priming of the pump is effected automatically as before.
In the arrangement shewn in Figure 3, the foot valve E closes automatically
upon its seat when the pump is unprimed and opens the valves B1, D1, of which B₁
communicates with the atmosphere while D' establishes communication between
the delivery and the suction at the bottom of the pump by means of pipe C.
The action in this arrangement is the same as before described, that is to say
when the pump is unprimed the valve A closes on its seat so as to cut off the
pressure of the delivery column upon the pump; the foot valve E also closes on
its seat owing to the stream of water by which it is raised being no longer
existent. The said valve E in closing, opens (as before stated), the valves B¹, D',
so that the air contained in the pump escapes through valve B₁, and the water is
reintroduced into the suction at the bottom of the pump so that the latter again
becomes primed automatically under the same conditions as before.
Figures and 6 represent two modifications of the automatic re-priming
apparatus in which the valves B¹, D are no longer controlled directly by the
valve A or by the foot valve E but are opened when the pump becomes unprimed
by the pressure of the water in the delivery pipe acting on a piston H fast on
the spindle of said valves. For this purpose the valve A (Figure 4) or the
foot-valve E (Figure 6) in closing on its seat raises an auxiliary valve F so as

page_text: to permit of water from the delivery pipe passing through pipe G and acting on
the under face of piston H so as to raise both valves B' D', the valve B¹ putting
the pump in communication with the atmosphere through pipe I, so as to permit
the escape of the accumulated air therefrom and the valve D permitting the
return of the water from the delivery pipe through pipe C to the suction pipe.
When by the accumulation of a certain quantity of air within the pump the
latter has become unprimed, the valve A (or valve E) closes on its seat and raises
the auxiliary valve F so as to allow the water from the delivery pipe to pass
through the pipe G and raise piston H and with it the two valves B, D₁, so as
to permit the escape of the accumulated air through valve B' and the return of
water from the delivery pipe through valve D₁ to the suction pipe so as to
re-prime the pump. When the pump has thus been re-primed the auxiliary
valve F is closed on its seat by means of valve A (Figure 4) or valve E (Figure 6)
which is opened by the water delivered or raised by the pump, whereupon pipe
G is opened to the atmosphere by a piston J on the spindle of valve F uncovering
outlet K and thus allowing the water beneath the piston H to escape and the
piston to descend to its lowest position by its own weight or by the stress of a
spring counterweight or otherwise, together with the two valves B, D, which
close on their seats and respectively shut off all communication between the
interior of the pump and the atmosphere and between the delivery and suction
pipes.
It has been before stated that the water for repriming may be supplied from a
tank. and Figure 7 shews such an arrangement. From the tank leads a pipe G
which conducts the water for re-priming into the suction pipe. The admission
of the water for re-priming and the discharge of the air contained in the pump
are regulated by the two valves B', D', controlled by the foot valve E as before
explained. When the height of the delivery column is but slight the non-
return delivery valve may be dispensed with and also the air-escape valve, as in
this case the air may escape naturally through the delivery pipe.
The re-priming may also be effected by electrical means, since many centrifugal
pumps are actuated by dynamos.
Figure 8 shews a centrifugal pump in which the two valves B¹, D¹, are elec-
trically operated. The said valves are both mounted upon the same lever L
which is jointed to a soft iron core M influenced by a solenoid N. When the
pump becomes unprimed, owing to the dynamo having less work to do, a portion
of the current traverses the solenoid, the core M becomes attracted, and both
valves B, D are opened.
All the above arrangements are also capable of being controlled by electrical
means. Thus as shewn in Figures 9 and 10, the re-priming apparatus instead of
being actuated by the suction valve or delivery valve are controlled as above
described by a solenoid N placed in the principal circuit of the motor or by any
suitable electrical apparatus whose action is based on the diminution in intensity
of the current which is produced when the pump draws in air or becomes un-
primed.
When the pump is immersed the foot valve E, pipe C leading to the suction,
cock D, or valve D¹, would not be required. In the event of air entering the pump
and unpriming it when the sump is pumped dry, the water necessary for re-prim-
ing would naturally enter the pump on the rising of the water level but the valve A.
is always indispensable, as well as cock B or valve B¹ for enabling the discharge
of the air which determines the re-priming, if the pressure above the pump is
still maintained.
The centrifugal action of the pump produces a whirling motion at the centre
of the column of liquid supplied by the suction pipe and thus impedes the priming
of the pump, and in order to remedy this defect there is applied to the inner end
of the suction pipe an anti-whirling device O provided with fixed radiating
blades P of straight or curved form so disposed as to direct the water into the
pump as shewn in Figures 4 and 5. This device also has the further advantage of

page_text: preventing the momentum of the water raised from acting prejudicially upon
the pump.
The re-priming apparatus and anti-whirling device herein described may be
applied, either together or separately, to all kinds of centrifugal pumps whether
horizontal or vertical and whether having one or two inlets, and in the case of
a submerged pump, either with or without a foot valve.
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. The combination, with a centrifugal pump, of apparatus adapted to effect
the re-priming of the pump by cutting off the back pressure of the water in the
delivery pipe, discharging the air which has occasioned the unpriming and
re-introducing water into the suction pipe, substantially as specified.
2. A repriming device for centrifugal pumps adapted to be operated by hand.
comprising a non-return valve in the delivery pipe; a discharge cock open to
the atmosphere placed below said valve; a pipe provided with a cock for con-
necting the delivery with the suction pipe, the two cocks being capable of being
operated at one time as specified.
3. The combination with a centrifugal pump of a repriming device adapted to
be controlled either by the non-return delivery valve or by the non-return suction
valve and comprising a non-return valve in the delivery pipe, a discharge valve
open to the atmosphere, and a discharge pipe provided with a valve for connecting
the delivery with the suction pipe, substantially as specified.
4. The combination with a centrifugal pump of an automatically operating
re-priming device of the kind specified in which a pair of valves open under the
action of the pressure of the water contained in the delivery pipe or in a tank
above the pump, through the medium of a piston fast on the spindle of said valves
and of an auxiliary valve which opens when the delivery valve or suction valve
closes, so as to permit the water from the delivery pipe or everhead tank to
act upon one face of the piston, and which closes (when the pump is re-primed
and the non-return valve rises), by discharging the water forced beneath the
piston, so as to permit the latter to return to its original position and close the
valves, substantially as specified.
5. In apparatus of the kind specified for effecting the automatic re-priming of
centrifugal pumps, the employment of means for electrically controlling the air
discharge and suction refilling valves, substantially as described with reference
to Figures 8, 9, and 10 of the drawings.
6. In a centrifugal pump the application to the inner end of the suction pipe
of an anti-whirling device consisting of fixed radiating blades constructed sub-
stantially as described.
Dated this 29th day of January 1900.
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.