U.S. patent number 3,726,618 [Application Number 05/131,381] was granted by the patent office on 1973-04-10 for self-priming pump.
This patent grant is currently assigned to Johnston Pump Company. Invention is credited to John L. Dicmas.
United States Patent |
3,726,618 |
Dicmas |
April 10, 1973 |
SELF-PRIMING PUMP
Abstract
A vertical self-priming pump assembly for unloading bulk cargo
carriers is disclosed. The vertical pump has a column which ingests
fluid at its lower end and discharges fluid at its upper end. A
mixed flow pump is located at the lower end of the column, with
multiple turbine pumps located above the mixed flow pump. A poppet
valve and a bypass line with a check valve are used for
self-priming of the pump. A vent valve and a manual bypass line are
provided for initial priming of the pump. Fluid discharged at the
upper end of the column passes through a discharge conduit
containing a check valve to prevent flow back into the column.
Inventors: |
Dicmas; John L. (Arcadia,
CA) |
Assignee: |
Johnston Pump Company
(N/A)
|
Family
ID: |
22449211 |
Appl.
No.: |
05/131,381 |
Filed: |
April 5, 1971 |
Current U.S.
Class: |
415/11; 415/56.5;
415/56.2; 417/199.2 |
Current CPC
Class: |
F04D
9/005 (20130101) |
Current International
Class: |
F04D
9/00 (20060101); F01b 025/00 () |
Field of
Search: |
;415/11,53,72 ;417/199A
;137/117,513.5 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Husar; C. J.
Claims
I claim:
1. A pump assembly comprising:
a barrel adapted to contain a fluid,
an inlet to the barrel adapted to allow ingestion of the fluid from
a fluid supply into said barrel,
a column having a lower end adapted to ingest the fluid from the
barrel and an upper end adapted to discharge said fluid,
a mixed flow pump interior the column adjacent the lower end of
said column adapted to pump a mixture of the fluid and vapor,
multiple turbine pumps interior the column downstream of the mixed
flow pump,
a priming valve including a poppet valve assembly having a first
end connected directly to an opening in the column downstream of
the multiple turbine pumps and a second end leading into the
barrel, said poppet valve assembly adapted to allow passage of the
fluid from the column into the barrel when open and to prevent
passage of said fluid from the column into said barrel when closed,
said poppet valve assembly adapted to be held in the closed
position by greater pressure in said column relative to pressure in
said barrel,
means for biasing the poppet valve assembly to the open
position,
a discharge conduit connected to the upper end of the column and
adapted to receive the fluid discharged therefrom,
a discharge check valve located in the discharge conduit and
adapted to prevent flow of the fluid through said discharge conduit
into the column and permit flow of said fluid out of said column
through said discharge conduit,
an automatic bypass line having a first end connected to the
discharge conduit upstream of the discharge check valve and a
second end connected to the barrel,
and
a bypass check valve interior the automatic bypass line and adapted
to prevent flow of the fluid from the discharge conduit to the
barrel through the automatic bypass line and adapted to allow flow
of air from the barrel to the discharge conduit through the
automatic bypass line.
2. A device as recited in claim 1 and additionally comprising:
a manual bypass line having a first end connected to the discharge
conduit upstream of the discharge check valve and a second end
connected to the discharge conduit downstream of the discharge
check valve,
a manual bypass valve interior the manual bypass line and adapted
to allow passage of the fluid through the manual bypass line when
open and adapted to prevent passage of the fluid through said
manual bypass line when closed,
and
a vent valve located on the discharge conduit upstream of the
discharge check valve and adapted to remove air from said column
when open.
3. A device as recited in claim 1 wherein the means for biasing the
poppet valve assembly to the open position comprises:
a spring adapted to bias the poppet valve assembly to the open
position, and
means for adjusting the compression of the spring.
4. A device as recited in claim 3 wherein the spring is a helical
spring adapted to flex along its longitudinal axis and wherein the
means for adjusting the compression of the spring comprises:
a movable plate adapted to abut the helical spring and move along
the longitudinal axis of said helical spring,
a set screw connected to the movable plate and adapted to move said
movable plate along the longitudinal axis of the helical spring
when said set screw is rotated,
and
a removable cap adapted to fit over and protect the set screw and
adapted to be removed.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to pumping devices, and in particular to
self-priming pump devices used to unload bulk cargo carriers.
2. Description of the Prior Art
A pump used to unload bulk cargo from a barge or tanker must be
capable of two stages of operation. First, when the vessel has a
substantial quantity of cargo, the pump must be capable of pumping
large volumes at a high rate. Second, when the vessel is nearly
empty, the pump must be capable of stripping the last remaining
cargo from the vessel. Hence the pump must be capable of both high
and low volume pumping.
In the past, pumps have been used for unloading bulk cargo from
barges which either had a large volume capability but were not
efficient for stripping remaining cargo, or which were efficient
for stripping but suffered from low volume capacity. In the present
invention, a pump is shown which is capable of very high volume
operation, but yet is capable of stripping the last cargo from the
vessel.
In the present invention, there are multiple turbine pumps which
give the pump a large volume flow capability. In combination with
the turbine pumps, a single propeller or mixed flow pump is
provided which is capable of pumping a mixture of vapor and fluid.
The propeller pump acts with a self-priming valve and an automatic
bypass line to provide capability of stripping the last remaining
fluid in the vessel. The mixed flow pump and the self-priming and
automatic bypass lines do not hinder the high volume flow possible
with the multiple turbine pumps. Hence the present invention
satisfies both objectives of a pump to be used for unloading bulk
cargo.
SUMMARY OF THE INVENTION
The invention comprises a fluid source adapted to contain a fluid
and a column whose lower end ingests fluid from the fluid source.
The fluid is discharged at the upper end of the column into a
discharge conduit. A first pump stage is located inside the column
near the lower end, and a second pump stage is located inside the
column above the first pump stage. A priming valve assembly is
connected to the column downstream of the second pump stage. The
priming valve assembly allows passage of the fluid from the column
into the fluid source when it is open and prevents such flow when
it is closed.
A discharge check valve is located within the discharge conduit.
The discharge check valve allows flow of the fluid out of the
column and through the discharge column, but prevents flow in the
opposite direction. An automatic bypass line is connected at one
end to the discharge conduit upstream of the discharge check valve
and at the other end to the fluid source. A bypass check valve is
inside the automatic bypass line which prevents flow of the fluid
from the discharge conduit to the fluid source through the
automatic bypass line but allows for the flow of air from the fluid
source to the discharge conduit through the automatic bypass
line.
The novel features which are believed to be characteristic of the
invention, both as to organization and method of operation,
together with further objects and advantages thereof will be better
understood from the following description considered in connection
with the accompanying drawings in which several preferred
embodiments of the invention are illustrated by way of example. It
is to be expressly understood, however, that the drawings are for
the purpose of illustration and description only and are not
intended as a definition of the limits of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of one embodiment of the invention wherein
the barrel covers only the lower portion of the column.
FIG. 2 is a top view of the embodiment of FIG. 1.
FIG. 3 is a front cross-section view of the priming valve
assembly.
FIG. 4 is a front cross-section view of the bypass check valve.
FIG. 5 is a front view of an embodiment of the invention wherein
the barrel covers nearly the entire column.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, an embodiment of the pump assembly which might
be used in a tanker wherein the fluid is kept at a lower level than
the deck of the vessel is illustrated. A fluid 10 which is stored
in a fluid supply 12 is free to pass through an inlet 14 to the
barrel 16 which acts as a fluid source to the column 18. The fluid
10 is ingested into the column 18 at its lower end 20. To
facilitate entry of the fluid 10 into the lower end 20 of the
column 18, the lower end may be flared as shown in the figure.
A first pump stage 22 is located near the lower end 20 of the
column 18. The first pump stage 22 is a mixed flow or propeller
type pump which is capable of pumping mixtures of the fluid 10 and
vapor which might enter the first pump stage 22 when it is not
fully primed. Downstream of the first pump stage 22 is a second
pump stage consisting of multiple turbine pumps 24 and 26. The
fluid 10 is ingested into the lower end 20 of the column 18, and is
then impelled upward through the column 18 by the first pump stage
22 and then the multiple turbine pumps 24 and 26.
The fluid 10 passes out the upper end 28 of the column 18 into a
discharge conduit 30. A discharge check valve 32 is located in the
discharge line 30. The discharge check valve 32 can be of the type
indicated in FIG. 1 wherein a disc 34 is pivoted about a point 36
near the edge of the disc 34. When the fluid is passing through the
discharge conduit 30 in the normal manner out of the column 18 as
indicated by the arrow 38, the disc 34 pivots up out of the path of
the fluid 10 and does not impede that flow. However, if the fluid
10 is moving in the opposite direction (not shown) through the
discharge conduit 30 into the column 18, the disc 34 pivots down to
abut a ring 40 as indicated in FIG. 1 to seal the discharge column
30 and prevent such flow.
Referring still to FIG. 1, a priming valve assembly 42 is connected
to the column 18 just downstream of the multiple turbine pumps 24
and 26. In the embodiment shown, the priming valve assembly 42 is
located above the barrel 16. The priming valve assembly 42 is
adapted so as to allow flow of the fluid 10 from the column 18 into
the barrel 16 when the first pump stage 22 is unprimed. However,
when the pump assembly is in normal operation, the priming valve
assembly 42 prevents flow between the column 18 and the barrel 16
through the priming valve assembly 42.
An automatic bypass line 44 is connected to the discharge conduit
30 upstream of the discharge check valve 32 at one end and to the
barrel 16 at the other end. A bypass check valve 46 is located on
the automatic bypass line 44. The bypass check valve 46 operates to
prevent flow of the fluid 10 from the discharge conduit 30 to the
barrel 16 through the automatic bypass line 44, but allows air or
vapor to pass from the barrel 16 to the discharge column 30.
A vent valve 48 is provided on the discharge column 30. The vent
valve 48 is normally closed, but can be opened manually to remove
air from the discharge column 30 for manual priming when
desired.
In the embodiment shown in FIG. 1, a motor 50 is provided with an
output shaft 52 to drive the first pump stage 22 and the multiple
turbine pumps 24 and 26. The output shaft 52 extends through the
column 18 to the pump stages to rotate those stages. The entire
device is shown in rest on a flat plate 54 which rests on the deck
56 or other structure of the vessel to be unloaded. The column 18
passes through a hole 58 in the deck 56 to reach the cargo
area.
Referring to FIG. 2, a top view of the pump assembly shown in FIG.
1 is presented. In this view, the position of the discharge conduit
30 with the discharge check valve 32 relative to the motor 50 and
the flat plate 54 is indicated. The location of the bypass check
valve 46 on the automatic bypass line 44 can easily be seen in this
view. The position of the vent valve 48 on the discharge conduit 30
is also apparent. The flow of fluid through the discharge conduit
30 during normal operation of the pump is indicated by the arrow
38.
In FIG. 2, the manual bypass line 60 which could not be seen in
FIG. 1 is shown. The manual bypass line 60 is connected to the
discharge conduit 30 upstream of the discharge check valve 32 at
one end and downstream of the discharge check valve 32 at the other
end. A manual bypass valve 62 is located on the manual bypass line
60. The manual bypass valve 62 is closed during normal operation of
the pump assembly, but may be opened manually for initial
priming.
Referring to FIG. 3, the priming valve assembly 42 is illustrated
in detail. The priming valve assembly 42 is attached to the column
18 at one end and to the barrel 16 at the other end. The priming
valve assembly 42 illustrated is of the poppet type, having a head
70 attached to a slidable stem 72 which acts to seal off a port 74.
The head 70 of the valve is biased in its open position denoted by
the dashed line 76 by a helical spring 78. The helical spring 78
surrounds the slidable stem 72 and the flexing of the helical
spring 78 about its longitudinal axis acts to bias the head 70 in
the open position 76.
The helical spring 78 abuts a movable plate 80 which is attached to
a set screw 82. The set screw 82 is threaded into the structure of
the valve 84 such that rotation of the set screw 82 moves the
movable plate 80 along the longitudinal axis of the helical spring
78. By adjusting the position of the set screw 82, the compression
on the helical spring 78 required to close the valve head 70 can be
adjusted. A removable cap 86 is placed over the set screw 82 to
protect the set screw but which can easily be removed for access to
the set screw 82 for adjustment. Removal of the cap 86 also
provides ready access to the stem 72 so that it may be manually
manipulated. This feature has been found to be extremely important.
If a valve such as the priming valve 42 is not used for a long
period of time it sometimes sticks. Prior art valves require
extensive dismantling of the pump structure to reach the priming
valve.
The bypass check valve 46 is illustrated in detail in FIG. 4. The
bypass check valve 46 is located on the automatic bypass line 44.
The bypass check valve 46 shown has a disc 90 which is pivoted
about a point 92 near the edge of the disc 90. An arm 94 is
connected to the disc 90 near the center of the disc at one end,
and is pivotable about the pivot point 92. When the pump assembly
is in normal operation, fluid enters the automatic bypass line 44
as indicated by the arrow 96. Movement of the fluid in this manner
causes the disc 90 to be pivoted downward and to abut against the
annular ring 98, which seals the automatic bypass line 44 and
prevents flow of fluid in the direction 96.
When the pump assembly loses prime fluid will not be pumped in the
direction 96. Lack of fluid pressure on the right side (as viewed
in FIG. 4) of the disc 90 will allow it to be pivoted upward by the
force of air pressure from the barrel 16 in the opposite direction.
The disc 90 will pivot out of the flow of air and will not restrict
such flow.
Referring to FIG. 5, an embodiment of the pump assembly which might
be used with a barge where the cargo fills all of the area below
the deck is illustrated. In this embodiment, the barrel 100 covers
almost the entire length of the column 102. The priming valve
assembly 104 is located within the barrel 100, but still provides a
means for fluid to flow from the column 102 above the multiple
turbine pumps 106 and 108 into the barrel 100 when the first pump
stage 110 is unprimed.
The barrel 100 has an inlet 112 which allows fluid 114 to enter the
barrel. The fluid 114 is ingested into the lower end 116 of the
column 102 and impelled upward by the first pump stage 110 and the
multiple turbine pumps 106 and 108. The fluid 114 is discharged
near the upper end 118 of the column 102 into the discharge conduit
120. The discharge conduit 120 has a discharge check valve 122
which prevents flow of the fluid from the discharge conduit 120
back into the column 102. An automatic bypass line 124 having a
bypass check valve 126 is attached to the discharge conduit 120 at
one end and the barrel 100 at the other end which permits flow of
air from the barrel 100 to the discharge conduit 120 but prevents
flow of fluid 114 from the discharge conduit 120 to the barrel
100.
The pump assembly is driven by a motor 128 having a drive shaft 130
which rotates the multiple turbine pumps 106 and 108 and the first
pump stage 110. The pump assembly rests on a flat plate 132 mounted
on the deck 134 or other structure of the vessel which is to be
unloaded.
The operation of the pump assembly can be easily demonstrated from
the above illustrations. In normal operation, fluid 10 enters the
barrel 16 from a fluid source 12. The fluid 10 is ingested into the
lower end 20 of the column 18, impelled upward through the column
by the first pump stage 22 and the multiple turbine pumps 24 and
26. The fluid 10 is discharged at the upper end 28 of the column 18
into a discharge conduit 30. The first pump stage 22 and the
multiple turbine pumps are driven by a motor 50.
In normal operation of the pump assembly, the priming valve
assembly 42, the bypass check valve 46, the vent valve 48 and the
manual bypass valve 62 are closed. The discharge check valve 32 is
open to allow free flow of the fluid 10 through the discharge
conduit 30.
When the level of the fluid 10 in the barrel 16 falls below the
lower end 20 of the column 18, the first pump stage 22 loses prime.
When this occurs, the multiple turbine pumps 24 and 26 will also
lose prime, and the normal flow of fluid 10 will stop. When the
normal flow of fluid 10 stops, the pressure difference between the
column 18 and the barrel 16 which held the priming valve assembly
42 in the closed position will decrease, allowing the priming valve
assembly to open. With the priming valve assembly 42 open, the
fluid 10 can flow back from the column 18 into the barrel 16 to
reprime the first pump stage 22.
When the fluid flow through the discharge conduit 30 is stopped,
the discharge check valve 32 closes to prevent fluid which has
already been pumped from reentering the column 18. To prevent a
formation of a vacuum in the discharge column 30, an automatic
bypass line 44 is provided. The automatic bypass line 44 has a
bypass check valve 46, but this valve allows air to pass from the
barrel 16 to the discharge column 30 to prevent formation of a
vacuum and facilities flow to fluid 10 to prime the first pump
stage 22.
The pump assembly is provided with two methods of initial priming
of the pump manually. The vent valve 48 may be opened which allows
fluid 10 which is in the column 18 to flow into the barrel 16 for
priming. The vent valve 48 is operated manually, and eliminates the
vacuum which retains the fluid in the column 18. The pump assembly
may be also primed with fluid 10 in the discharge conduit 30
upstream of the discharge check valve 32. The manual bypass valve
62 may be opened to allow fluid in the discharge conduit 30
upstream of the discharge check valve 32 to flow through the manual
bypass line 60. In this manner the fluid 10 is allowed to flow back
into the column 18 to prime the pump assembly.
* * * * *