Improvements in Centrifugal Pumps.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Centrifugal Pumps.
We, JOHN GWYNNE, of 64, Cannon Street, in the City of London, Engineer, and
EDWARD WASHBOURN SARGEANT, of Hammersmith Iron Works, Hammersmith,
in the County of Middlesex, Engineer, do hereby declare the nature of this inven-
tion to be as follows:-
-
To enable a centrifugal pump to be started, it is usual to provide the upper part
of the pump casing with an ejector which, upon a jet of steam being passed
therethrough and the discharge pipe of the pump closed by a sluice or other
valve, will cause the air to be exhausted from the pump casing, which will then
become charged with water through the suction pipe and upon the valve in the
discharge pipe being opened whilst the wheel or propeller of the pump is rotated,
pumping will become continuous. Sometimes, for instance, in the case of belt
or electric motor driven pumps, steam for the ejector cannot be readily obtained
and the object of this invention is to obviate this difficulty, for which purpose
according thereto the pump casing is provided with an ejector adapted to be
operated by means of a jet of water supplied by a supplementary pump, which
may be so arranged as to propel the same body of water through the ejector over
and over again.
In one arrangement, the supplementary pump is of the centrifugal type, is
secured to the casing of the main pump and is arranged to be driven from the
main pump by a belt passing around pulleys on the shafts of the two pumps.
Above and connected to the suction of the supplementary pump is a tank which
may be of funnel shape. The delivery of the said pump is connected to the
pressure side of the ejector, the delivery pipe of which discharges into the said
tank and the suction branch of which communicates with the pump casing
through a cock.
The action is as follows:-The suction pipe of the main centrifugal pump being
immersed in the suction water and its delivery being closed by a clack or sluice
valve, or being immersed in the delivery water where the same is below the
pump, a sufficient quantity of water is poured into the tank to charge it and
the supplementary pump. The cock on the suction branch of the ejector is
opened and shaft of the main pump is then rotated and with it that of the
supplementary pump which then causes water to flow from the tank through the
ejector and back to the tank again. This action causes a vacuum at the suction
branch of the ejector and withdraws the air from main pump casing and thus
causes the water in the suction pipe thereof to rise and charge the pump casing,
whereupon the ejector will deliver an extra quantity of water, which it draws
from main pump casing, into the tank and this surplus water will flow away
through an overflow pipe and thus show the attendant that the main pump is
charged. The ejector cock is then closed and the supplementary pump stopped
by throwing off the belt or in any other convenient way, as by means of a clutch
The main pump may be arranged to swivel on its bedplate and so change the

page_text: position of its branches and the charging pump is then also arranged to swivel
on the main pump casing so that the tank may always be in the proper position ;
the ejector is always placed on the highest part of pump casing.
The supplementary pump may be arranged to supply water under pressure
to the main pump glands and bearings in order to prevent the access thereto
of grit or other foreign matter contained in the liquid being pumped. The
supplementary pump casing may conveniently be formed with a cylindrical lateral
extension adapted to fit into a socket formed on the delivery branch of the main
pump casing.
Centrifugal rumps.
We, JOHN GWYNNE, of 64, Cannon Street, in the City of London, Engineer, and
EDWARD WASILBOURN SARGEANT, of Hammersmith Iron Works, Hammersmith,
in the County of Middlesex, Engineer, do hereby declare the nature of this inven-
tion and in what manner the same is to be performed to be particularly described
and ascertained in and by the following statement:-
-
To enable a centrifugal pump to be started, it is usual to provide the upper part
of the pump casing with an ejector which, upon a jet of steam being passed
therethrough and the discharge pipe of the pump being closed by a sluice or other
valve, will cause the air to be exhausted from the pump casing, which will be-
come charged with water through the suction pipe; upon the valve in the discharge
pipe being then opened whilst the wheel or propeller of the pump is rotated,
pumping will become continuous. Sometimes, for instance, in the case of belt
or electric motor driven pumps, steam for the ejector cannot be readily obtained
and the object of this invention is to obviate this difficulty, for which purpose
according thereto the pump casing is provided with an ejector adapted to be
operated by means of a jet of water supplied by a supplementary pump, which
may be so arranged as to propel the same body of water through the ejector over
and over again.
In the arrangement illustrated in the accompanying drawings, whereof Figs. 1
and 2 are elevations at right angles to each other and Fig. 3 a plan, the supple-
mentary pump 1 is of the centrifugal type, is secured to the casing of the main.
pump 2 and is arranged to be driven from the main pump by a belt 3 passing
around pulleys 4 and 5 on the shafts of the two pumps. Above and connected
to the suction 6 of the supplementary pump is a tank 7 which may be of funnel
shape as shown. The delivery 8 of the said pump is connected to the pressure
side of the ejector 9, the delivery pipe 10 of which discharges into the tank 7
and the suction branch 11 of which communicates with the main pump casing
through a cock 12.
The action is as follows:-The suction pipe of the main centrifugal pump being
immersed in the suction water and its delivery being closed by a clack or sluice
valve, not shown, or being immersed in the delivery water where the same is below
the pump, a sufficient quantity of water is poured into the tank 7 to charge it and
the supplementary pump 1. The cock 12 on the suction branch of the ejector
is opened and the shaft of the main pump rotated and with it that of the supple-

page_text: mentary pump which then causes water to flow from the tank 7 through the
ejector 9 and back to the tank 7 again. This action reduces the pressure in the
suction branch of the ejector and withdraws the air from main pump casing and
thus causes the water in the suction pipe thereof to rise and charge the main
pump casing, whereupon the ejector 9 will deliver an extra quantity
of water, which it draws from main pump casing, into the tank
7 and this surplus water will flow away through an overflow pipe 13
and thus show the attendant that the main pump is charged. The
ejector cock 12 is then closed and the supplementary pump stopped by
throwing off the belt 3 or in any other convenient way, as by means of a clutch.
Sometimes the main pump is arranged to swivel on its bed plate so as to enable
the position of its branches to be changed; the pump 1 is then also arranged to
swivel on the main pump casing so that the tank 7 may always be in the proper
position; for this purpose, the casing of the pump 1 may conveniently be formed
with a cylindrical lateral extension 1 adapted to fit into a socket 14 formed on
the delivery branch of the main pump casing, bolts and bolt holes being pro-
vided to enable the pump 1 to be secured in the desired position relatively to
the main pump. The ejector 9 is always placed on the highest part of pump
casing.
The supplementary pump may be arranged to supply water under pressure
to the main pump glands and bearings in order to prevent the access thereto
of grit or other foreign matter contained in the liquid being pumped.
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. The combination with a centrifugal pump of an ejector adapted to bę
operated by a jet of water supplied by a supplementary pump for the purpose of
enabling the centrifugal pump to be started substantially as described.
2. The combination with a centrifugal pump of an ejector operated by means
of a jet of water and the suction branch of which communicates with the
interior of the main pump casing, and a supplementary pump the delivery of
which communicates with the pressure side of the ejector and the suction of
which is connected with an elevated water supply tank into which the delivery
of the ejector discharges, substantially as described.
3. A centrifugal pump having combined therewith a supplementary centrifugal
pump and ejector constructed arranged and operating as described with reference
to and shown in the accompanying drawings.
Dated this 8th day of Santambor 1800