Submerged pumping system

Abstract

A submersible pumping system especially adapted to cryogenic storage systems which includes a single fluid transmitting casing extending from the top to near the bottom of the storage container, a normally closed spring biased foot valve on the bottom of the casing, a sealing gland closing the top of the casing having a shiftable portion, and a pump and motor unit suspended through the shiftable portion of the sealing gland in the casing and adapted to open the foot valve. The pump and motor unit is centered in the casing and aligned with the foot valve by mating frusto-conical collars associated with the pump and motor unit and with the valve assembly. The shiftable sealing gland allows the pump and motor unit to be lifted off the foot valve so as to close the valve without venting the casing.

I claim as my invention: 
     
       1. An assembly adapted for pumping fluids from storage containers and permitting safe removal of pumping equipment without loss of fluid or pressure which comprises a single fluid transmitting casing for extending from the top to the bottom portions of a storage container, a normally closed valve at the bottom of the casing sealing the interior of the casing from the storage container, a fluid outlet at the upper portion of the casing, a sealing gland having a shiftable portion at the top of the casing, a pump and motor unit suspended by means passing through said shiftable portion of said sealing gland in said casing, said unit being adapted to bias the valve to an open position at the bottom of the casing for receiving fluid from the reservoir to flow said fluid through the unit and casing to the outlet thereof, and said shiftable portion of sealing gland accommodating sufficient shifting movement of said means to permit opening and closing of the valve by the pumping unit without venting the casing. 
     
     
       2. A submersible pumping system particularly adapted for pumping cryogenic fluids from reservoirs which comprises a single fluid transmitting casing adapted to depend vertically from the roof to the bottom portion of the storage reservoir, a foot valve normally closing the bottom end of said casing, a sealing gland with a vertically shiftable portion normally closing the top of said casing, a valved discharge outlet adjacent the top of said casing, a pump and motor unit fitting freely in said casing having a downwardly opening inlet adapted to engage the valve at the bottom of the casing for opening the valve to communicate the contents of the reservoir with the interior of the pump, said pump having a discharge outlet communicating with the casing, seal means between the casing and pump preventing flow into the casing except through the pump, means suspending the pump and motor unit through the shiftable sealing gland portion at the top of the casing and means for raising and lowering the shiftable portion of said gland to permit hte suspension means to raise the pump and motor unit off of the valve at the bottom of the casing for permitting closing of the valve and to permit lowering of the pump and motor unit against the valve to open the valve without venting the casing, and means at the top of the casing for purging the interor of the casing whereby removal of the pump and motor unit is accomplished without hazard and without loss of fluid or pressure by purging the cryogenic fluid in the casing through the pump and out of the opened valve back to the reservoir, by next raising the shiftable portion of the sealing gland to lift the pump and motor unit for permitting closure of the valve and by thereafter retracting the pump and motor unit out of the top of the casing for repair or replacement. 
     
     
       3. A pumping system which comprises a single fluid transmitting casing adapted to be suspended from the roof of a reservoir to extend to the bottom of the reservoir, a spring biased valve closing the bottom of the casing, a pump and motor unit adapted to be lowered through the casing to rest on the valve for opening the valve to the interior of the pump, a sealing gland having a shiftable portion at the top of the casing, means suspending the pump and motor unit in the casing through said sealing gland, said portion of said sealing gland adapted to be raised and lowered a sufficient distance so that the suspension means will raise or lower the pump and motor unit onto and off of the valve to effect opening and closing of the valve without venting the casing, and a purge port at the top of the casing adapted to introduce fluid under pressure for discharging fluid through the pump and out of the opened valve back to the reservoir whereby the pump and motor unit may be lifted out of the casing without venting the contents of the reservoir. 
     
     
       4. A pumping system especially suited for frozen hole cryogenic fluid storage reservoirs which comprises a single fluid transmitting vertical casing suspended from the roof of such a reservoir into close proximity with the bottom thereof, a spring biased foot valve closing the bottom of said casing, a pump and motor unit adapted to be lowered through said casing to rest on the foot valve for opening the valve to join the pump inlet with the interior of the reservoir and the pump outlet with the interior of the casing, means for suspending the pump and motor unit in the casing, a sealing gland at the top of the casing supporting the suspension means and having a sealed lift sufficient to cause the supension means to raise the pump and motor unit off of the valve to permit closing of the valve, whereby the pump and motor unit may be mounted for operation in the casing and removed from the casing without venting the casing to the atmosphere while the valve is open. 
     
     
       5. A .[.pump and motor unit adapted for lowering through.]. .Iadd.pumping system for liquefied gas comprising .Iaddend.a fluid transmitting conduit .Iadd.and a pump and motor unit adapted to be lowered into the conduit .Iaddend.to pump fluid through the conduit .[.which comprises.]..Iadd., said pump and motor unit comprising .Iaddend. a motor casing of smaller diameter than the conduit,   a pump casing mounted on said motor casing having a discharge outlet surrounding the motor casing to discharge fluid into the conduit around the motor casing,   means on said pump casing defining a downwardly opening pump inlet adapted to receive fluid,   a motor in said motor casing,   a shaft extending from said motor through said pump casing,   impeller means on said shaft coacting with the pump casing to pump fluid from the inlet to the conduit, and   a tapered seat for said unit at the bottom of said conduit to mount the unit centrally in the conduit and to seal the bottom of the conduit except through the pump.Iadd.; and   means for purging the interior of the conduit.Iaddend..   
     
     
       6. A .[.pump and motor unit.]. .Iadd.pumping system .Iaddend.according to claim 5 including an inducer impeller on the shaft in the inlet and primary and secondary impellers on the shaft in the pump casing. 
     
     
       7. A .[.pump and motor unit.]. .Iadd.pumping system .Iaddend.according to claim 5 wherein a spring biased foot valve controlling flow to the pump inlet is opened by the weight of the unit thereon. 
     
     
       8. .[.The unit of.]. .Iadd.A pumping system according to .Iaddend.claim 5 wherein the .Iadd.upper end of said .Iaddend.shaft is rotatably mounted in a bearing and a settling basin .Iadd.in said motor casing above said bearing is .Iaddend.vented to the pumped fliud .[.supplies.]. .Iadd.through a port in the motor casing wall to supply .Iaddend.clear fluid through a stand pipe .Iadd.in said basin .Iaddend.to the bearing.Iadd., said stand pipe extending upwardly from said bearing.Iaddend.. 
     
     
       9. A pressure lock between a main pressurized storage container and the external atmosphere comprising, a sealed closure for the top of said storage container, a single pumped fluid transmitting casing extending downwardly through said closure into said storage container and supported on and sealed to the closure, with its bottom spaced above the bottom of said storage container, a foot valve at the bottom of said casing, means biasing said foot valve to close the bottom of said casing, a pump and motor unit guided for movement along said casing including a motor and a pump disposed therebeneath and driven thereby and having an inlet opening to the bottom of said pump and motor unit an annular abutment face encircling said inlet and adapted to engage and open said valve by the weight of said pump and motor unit thereon to provide a fluid pumping passageway to the interior of said storage container as said pump and motor unit is lowered to its extreme limits of downward movement along said casing, a sealing gland having a slidable portion at the top of said casing and means passing through said gland suspending said pump and motor within said casing. 
     
     
       10. The structure of claim 9, wherein means are provided for guiding said pump and motor unit downwardly along said casing and wherein cooperating frusto-conical surfaces extending inwardly of said casing and about said pump and motor unit centrally seat said pump and motor unit in said casing, seal said pump and motor unit to said casing, and maintain said inlet in fluid pumping association with said valve. 
     
     
       11. The structure of claim 9, wherein a generally annular open ended housing is secured to the bottom of said casing and depends therefrom, wherein said foot valve is disposed beneath said annular housing and is downwardly movable with respect thereto to provide fluid communication with said pump and motor unit, wherein cooperating internal and external frusto-conical sealing faces on said pump and motor unit and said housing maintain said pump and motor unit in sealed relation with respect to said housing and center said pump and motor unit with respect to the interior of said housing, and wherein spring means connected between said housing and foot valve bias said foot valve into a closed position. 
     
     
       12. The structure of claim 11, wherein manually operable jogger means operable from the top of said closure is provided to jog said foot valve into a closed position upon failure of said spring to close said valve. 
     
     
       13. The structure of claim 11, wherein a cap is sealed to the top of said casing, wherein a flexible cable suspends said pump and motor unit from said cap, and wherein flexible electrical conductors sealed to said cap and said pump and motor unit supply electrical power to energize said motor. 
     
     
       14. A lock particularly adapted for a main storage container storing gases in liquid from under pressure and accommodating purging of the reservoir of fluid and flammable gas and the pumping of pressurized liquid gas therein from the container comprising, a sealed closure for the top of the storage container, a single pumped fluid transmitting casing sealed to said closure and extending therethrough and supported thereon with its bottom in vertically spaced relation with respect to the bottom of said storage container, a foot valve extending beneath the bottom of said casing, spring means suspending said valve from said casing and biasing said valve into position to seal the open bottom end of said casing, said foot valve having an inlet fitting spaced inwardly of said casing, a pump and motor unit guided for movement along said casing, a cap sealed to the top of said casing and supporting said pump and motor unit in said casing adjacent the bottom thereof and accommodating raising and lowering of said pump and motor unit along said casing, said pump and motor unit including a motor and a pump disposed therebeneath and driven therefrom and having a downwardly opening inlet opening, means guiding said pump and motor unit to register with said inlet fitting on said foot valve and open said foot valve against said spring means by the weight of said pump and motor unit thereon, and centering said pump and motor unit with respect to said foot valve and retaining said pump and motor unit from rotation, said guiding means comprising, mating internal and external frusto-conical centering surfaces in association with said casing and said pump and motor unit and spaced leaving radial vanes in association with said casing and said pump and motor unit. 
     
     
       15. In a submerged pumping system having a storage container, with a casing extending from the top to the bottom portions thereof and a removable pump and motor unit slidably received in the casing, the improvement of a spring biased normally closed valve means depending from the bottom of the casing and adapted to be opened by the weight of the pump and motor unit to vent the bottom of the casing to the container and cooperating tapered means associated with the unit and valve means to align the unit with the valve means, center the unit in the casing, seat the unit in the casing, and seal the casing from the storage container except through the unit. 
     
     
       16. In a submersible pumping system including a storage container, a casing extending from the top to the bottom portions thereof, and a removable pump and motor unit received in said casing, the improvement of a foot valve means sealing and communicating the casing to the storage container, said valve means spring biased in a closed position, said valve means having an .Iadd.annular .Iaddend.abutting face interiorally of said casing, said valve means having a generally annular frusto-conical seating face associated therewith spaced from the abutting face, said valve means depending from the casing, said pump and motor unit having .Iadd.a downwardly opening pump inlet and .Iaddend.an .Iadd.annular .Iaddend.abutting face .[.on the bottom thereof.]. .Iadd.encircling said inlet .Iaddend.adapted to mate with the abutting face of the valve means to overcome the spring bias and open the valve means by the weight of the pump and motor unit and said pump and motor unit having a generally annular frusto-conical seating face therearound adapted to mate with the said seating face associated with the foot valve means to seat the pump and motor unit at the bottom of the casing and to center the unit in the casing and to align the said abutting face on the unit for mating with the abutting face of the valve means whereby the mating of the frusto-conical seating faces properly aligns the pump and motor unit with the valve means. .Iadd. 17. An assembly as claimed in claim 1, wherein said pump and motor unit includes a motor and a pump disposed therebeneath and driven by said motor,   said pump includes a pump outlet in communication with the interior of the casing and a pump inlet having an annular abutment face formed thereon which encircles said pump inlet,   said normally closed valve including a movable foot plate biased toward a closed position, said movable foot plate including an inlet fitting opening to the periphery of said foot plate,   said annular abutment face engaging said inlet fitting of said normally closed valve for opening the same under influence of the weight of said pump and motor unit to provide a sealed passageway for fluid exiting from the interior of the storage container through said inlet fitting to said pump inlet. .Iaddend..Iadd. 18. An assembly as claimed in claim 17, including   a plurality of springs circumferentially spaced around said inlet fitting, each of said springs being coupled between said foot plate and the casing to bias the valve toward a closed position. .Iaddend. .Iadd. 19. An assembly as claimed in claim 1, including   spaced radial vanes associated with the casing and the pump and motor unit for interleaving with one another to prevent rotation of the pump and motor when seated on said normally closed valve. .Iaddend..Iadd. 20. A pumping system as claimed in claim 3, wherein   said pump and motor unit includes a motor and a pump disposed therebeneath and driven by said motor,   said pump includes a pump outlet in communication with the interior of the casing and a pump inlet having annular abutment face formed thereon which encircles said pump inlet,   said spring biased valve including a movable foot plate biased toward a closed position, said movable foot plate including an inlet fitting opening to the periphery of said foot plate,   said annular abutment face engaging said inlet fitting of said spring biased valve for opening the same under influence of the weight of said pump and motor unit to provide a sealed passageway for fluid exiting from the interior of the storage container through said inlet fitting to said pump inlet. .Iaddend. .Iadd. 21. A pumping system as claimed in claim 20, including   a plurality of springs circumferentially spaced around said inlet fitting, each of said springs being coupled between said foot plate and the casing to bias the valve toward a closed position. .Iaddend..Iadd. 22. A pumping system as claimed in claim 3, including   spaced radial vanes associated with the casing and pump and motor unit for interleaving with one another to prevent rotation of the pump and motor unit in the casing when seated on the spring biased valve. .Iaddend..Iadd. 23. A pumping system as claimed in claim 3, wherein:   said suspension means is flexible. .Iaddend. .Iadd. 24. A pumping system as claimed in claim 4, wherein:   the pump of the pump and motor unit is disposed beneath the motor and driven thereby, said pump having an annular abutment face thereon which encircles the pump inlet,   said spring biased foot valve including a movable foot plate biased toward a closed position, said movable foot plate including an inlet fitting opening to the periphery of said foot plate,   said annular abutment face engaging said inlet fitting of said normally closed valve for opening the same under influence of the weight of said pump and motor unit to provide a sealed passageway for fluid exiting from the interior of the storage container through said inlet fitting to said pump inlet. .Iaddend..Iadd. 25. A pumping system as claimed in claim 24, including:   a plurality of springs circumferentially spaced around said inlet fitting, each of said springs being coupled between said foot plate and the casing to bias the foot valve toward a closed position. .Iaddend..Iadd. 26. A pumpng system as claimed in claim 4, including:   spaced radial vanes associated with the casing and the pump and motor unt for interleaving with one another to prevent rotation of the pump and motor when seated on the foot valve. .Iaddend..Iadd. 27. A pumping system as claimed in claim 4, wherein:   said suspension means is flexible. .Iaddend. .Iadd. 28. A pressure lock as claimed in claim 9, wherein:   said foot valve includes a movable foot plate with an inlet fitting opening to the periphery of said foot valve,   said annular abutment face engaging said inlet fitting of said foot valve for opening the same under influence of the weight of said pump and motor unit to provide a sealed passageway for fluid exiting from the interior of the storage container through said inlet fitting to said pump inlet. .Iaddend..Iadd. 29. A pressure lock as claimed in claim 28, wherein:   said biasing means including a plurality of springs circumferentially spaced around said inlet fitting, each of said springs being coupled between said foot plate and the casing to bias the foot valve toward a closed position. .Iaddend..Iadd. 30. A pressure lock as claimed in claim 3, including:   spaced radial vanes associated with the casing and the pump and motor unit for interleaving with one another and to prevent rotation of the pump and motor unit when seated on the foot valve. .Iaddend..Iadd. 31. A pressure lock as claimed in claim 9, wherein:   said suspension means in flexible. .Iaddend.