US1651881A - Pumping system - Google Patents

Description

R. E. FRICKEY ET AL PUMPING SYSTEM Original Filed Dec. 26, 1925 a INVEN Tons Royal E. Hickey .W. Raarf Lay/1e v arrest leakage fromany part of Patented Dec. 6, 1927.

. l ED STA,

ROYAL E. FBICKEY, OF SAN FRANCISCO, AND WILLIAM ROBERT LAYNE, 0F OAKLAND,"

canrronn'm.

I PUMPING SYSTEM. 1

Original application filed December28, 1925,.Seria1 No. 77,699. Divided and this application filed December 1, 1926.

' This invention relates to a system for pumping liquids which it is desired to keep out of contact with air. In the oilrefining industry it is oftennecessary topump or circulate hot oil at high pressure. The tem-' perature of such oil may be as high as 1000 degrees Fahrenheit and-the pressure "of the system as high as 1000 pounds per square inch. This is well above the flash point of such oils and if they are exposedto the air through leakage, instantaneous combustion occurs. To successfully pump such liquids a special type of pump is required which will obviate all danger of combustion through leaka e between the working parts. 'The s stem 0% this invention has been designe to solve this problem.

It is a further object of this invention to devise a pumping system in which leakage from between the stationary and movable members of the pump is arrested-by subjecting these parts to a fluid under pressure to oppose the pressure of the liquid in the system. a

It is a further object of this invention to a pump structure by submerging the entire housing of the pump in a body of liquid which is maintained at suflicient pressure to arrest leakage of liquid from the system in Whic the pump ma be employed. It is a furtl ier ob'ect of this invention to devise a pump for andling hot liquids in which the housing of the pump is submerged in a body of liquid and in which means .is provided for minimizing transmission of heat from thehousing thru the body of liquid.

It is a further object of this invention to devise a pumping system in which a reservoir is provided on the stationary member of the pump to surround the shaft of the same so as to store any leakage occurring,

around the shaft, and to maintain the level of the liquid in the'reservoir constant by subjecting it to the pressure of an inert gas,"

the pressure otthe gas bein automatically v controlled to maintain the liquid level substantially constant. It is proposed to supply the gas from a source of gas under pressure and to provide a float control valve for automatically controlling the supply of gas to the reservoir.

It-is a further object of this invention to By means of this base 21 the casing normally retained in upright or Vertical position.

Serial No. 151,855.

devise a pumping system in which an electric motor-pump unit is employed which is entirely enclosed within an air-tight casing and to provide an atmosphere of inert as 'within this casing. It is proposed todivide Further objects of the invention will appear from the following description in which heat of the liquid being circulating it about the drive shaft bearings.

there is set forth the preferred embodiment of the invention. It is to be understood that the invention is to be accorded a range of mechanical equivalents consistent with the state of the prior art. a

The single figure of the drawing shows a transverse sectional view of the com lete pump unit employed with the system 0 this invention.

1 The system contemplates generally the use of a motor-pump unit which is'entirely enclosed withlnan air-tight casing. Thus there is preferablyprovided a cylindrical casing 10 having an upper end member 11 and a lower end member 12. In order to securely clamp these end members to the casing 10,

the casing is provided along its upper end" with a flange 13 adapted to be secured to the flange 14 of the upper end member 11 by suitable means such as bolts 15. An annular asket 16 is inserted between the ,end of casmg 10 and the end member 11 to" insure an air-tight fit. The lower end of the casin 10' is similarly provided with the flange adapted to be secured to the flange 18 of the end member 12 by suitable means such as bolts 19. A gasket 20 .is also inserted be tween the lower end of casing 10 and the Y 4 lower end member 12. The vbolts'19'also serve to secure the casing 10 to the base 21. 10 is Within the lower portion of the casing. there is disposed a liquid pump designated generally as 22 while in theupper portion of the casing there is disposed a motor 23 which is preferably electrical.

The liquid pump 22 comprises the usual stationary and movable members and is preferably of theeentrifugal type. Accordingly, the pump 22 includes a pump housing 24 which may be split ciroumferentially to form an upper portion 25 and a lower portion 26. The lower portion 26 is provided with a peripheral flange 2'7 which is securely clamped to the flange 28 of the upper hous ing portion 25 by sultable means such as bolts 29. These bolts 29 also serve to secure the pump housing 24 to the casing 10 by means of an internal peripheral flange 30 which projects from the interior wall of the casing 10 and is preferably spaced from the lower end of the casing 10. The lower portion 26 of the pump housing is provided with suitable liquid intake and outlet passages which communicate with theexterionof the casing 10. Thus there is rovlded an intake pipe 33 which communicates with the intake opening 34 in the lower portion 26.

The pipe 33 is preferably formed as an integral continuation of the'end member 12 and is provided with a-suitable fluid-tight connection with the lower portion 26. This connection may be in the form of an annular groove 35 into which is fitted the annular 'tongue 36 extending from the end'of the lower side portion of the pump housing.

7 The outlet pipe-3'? is formed upon the periphery of the pump housing and registers with an exterior outlet pipe 38 which may either be bolted to the side of the casing 10 or may be formed integral therewith. The junction between pipes 37 and 38 need not be fluid-tight and may be merely abut-t joint as indicated at 39 from which fluid may leak into the lower portion of the casing. The pipes 33 and 38 are provided with suit able faces 39' and 40 for connection with any devised system of external piping.

\Vithin the hollow pump housing there is arranged a rotary impeller 42 which is mounted upon a rotatable shaft 43. The shaft 43 is arranged to extend vertically within the casing 10 and is suitably jour-- naled adjacent its lower end as by bearings 44 and 45. Within the upper portion of the casing 10 the motor 23 preferably has its armature 46 directly mounted upon the shaft- 43 to drive the same. The upper end of the shaft 43 is also provided with a suitable bearing 47 mounted adjacent the motor armature 46.

Means has also been provided for submerging the entire pump housing in a body of liquid. By maintaining this body of liquid under a pressure corresponding to the pressure Within the pump, stresses on the pump housing caused by internal pressure are minimized. Thus it is possible to employ a relatively light pump housing of cheap construction in a high pressure system, as the walls of the housing need only withstand compressional stresses caused by the opposed internal and external pressures. Another important function for this arrangement is to arrest leakage of liquid from the system. By confining the immersing body of liquidunder pressure to prevent its volume from increasing above a given maximum, all leakage from the pump is arrested and any leakage that may occur from the pump is re turned into thesystem. lVhen inflammable liquids such'as hot oil are pumped, the body of immersing liquid is-kept under pressure by an inert gas.

' llith the'specific type of pump which has been illustrated,- leakage will tend to occur I between the parts of the housing, between the housingqand the outlet pipe 38 and between the shaft 43 and thehousin When the pump is initially operated lea age will fill the lower portion of the casing to entirely submerge the pump. VVhenthe level of the immersing body of liquid rises to a certain predetermined levlit is placed under pressure by suitable means such as an inert connecting with a depending annular flange 49 formedv on the transverseplate'50. Thevplate 50 1s suitably secured to, aninternal casing flange 51 and is provided with an aperture 52 whichcloselyi fits the shaft 43.

The stationary parts ofthe bearing 45 may be mounted upon the flange-49.

In order to confin'etheu-pper surface of the immersing qliquid there is prefer'ablylprovided a shell 60 which is-suitablymounted upon the transverse plate 50 as by means of flange 61. The upper end of the shell 60 is provided with .an inturned portion 63 which serves asa mounting for the motor 23. The

shell 60 has a relatively large I cross-sectional area sozthat a relatively small fluctu-' ation of thelevel of any liquid within this shell will causea relativelv large amount of gas above the liquid t-o be displaced. It will'be noted that the arrangement of the shell 60 provides a partition-for the casing 10' which divides the casing 1 0 into a lower portion and an upper portion. Since the pump is adapted to be used in pumping liquid at high temperature this partition isv of material advantage in protecting the windings of the motor fromthe heat of the liquid beingpumpcd.

In order to maintain the immersing liquid under pressure there is provided an external storage tank 66 of inert gas such per surface of the liquid at a relatively low as nitrogen gas under pressure. This tank is provided with a suitable control valve 67 and is in communication with the interior of the shell 60 by means of a pipe 68. Within the casing there is provided a device for automatically controlling the supply of inert gas in accordance with the level of the In order to insure equal distribution ofthe pressure throughout the immersing liquid the plate is suitably apertured as at 73 and the pump housing is apertured'as at 74 so that communication is established between the liquid in the shell 60 and the liquid in the spaces 7 5 and 76. To prevent transmission of heat from the upper surface of the pump housing 24 thru the liquid in the space 7 5, aseries of spaced lateral bafiies 77 are provided. These battles are in the form of plates closely spaced together so as to retain thin heat insulating layers of liquid between the same. They also serve to minimize convection currents in the space 75. These baffles aid in maintaining the uptemperature.

Since the bearings 44 and 45 for the shaft 43 are submerged directly in the immersing liquid from the pump 22 it is necessary to provide some means for cooling the oil in the reservoir 47. in order to prevent injury to these bearings when the device is used to pump oil at high temperatures; -Means has accordingly been provided for by-passing a certain amount of the oil from the system and then circulating this oil down through the reservoir47'. However, before introducing this oil into this portion of the reservoir the oil is passed through a cooling system.

Thus there is provided a pipe 78 connected with the outlet pipe '38 of the pum 22 which by-passes a certain amount 0 oil from the outlet pipe 37 This outlet pipe. communicates with a system of cooling coils 79 which in turn communicates with the pipe 80 which introduces the cooled oil into the upper part of the reservoir 47 Therefore a downward current is produced and the bearings 45 and 44 are maintained at a relatively .low temperature compared to the temperature of the oil being pumped.

Provision has also been made for cooling the windings of the electric motor drive. Since the upper portion of the casing 10 is in communication with the shell 60 the motor will be subjected to an atmosphere of inert gas. This gas is preferably circulated over the motorwindings to more efi'ectively conduct away the heat. Thus the motor 23 is preferably provided with a small blower 82 which serves to blow the inert gas out of the interior of the upper portion of the casiug 10 through the pipe 83. The pipe 83 communicates with a system of cooling pipes represented diagrammatically by the dash and dot line 84' and from which the gas is again introduced into the casing 10 through the pipe 85. Thus the motor will be maiu tained ata sufficiently low operating tem perature to prevent injury to the windings. The electrical conductors 86 for the electric motor 23 preferably extend through the side of the casing 10- to suitable air-tight fittings 87.

In operation if the liquid being pumped is hot oil under high pressure. the oilwill initiallyv leak between the shaft 43 and the upper portion 25 of the pump housing 24 until it fills the shell 60 to the liquid level indicated at 88. Leakage will also occur between the pump housing portions andbelween the pump housing and casing 10 to fill spaces 75 and 76, or these spaces may be initially filled with oil. HoweverQwhen the liquid reaches this level the float is lifted to automatically cause the introduction of an inert gas from the storage reservoir 66 to the valve 69. This gas will then press down upon the surface 88 of the liquid and will arrest further leakage by opposing the pressure I of the liquid being pumped. The float controlled valve 69will automatically regulate the supply of inert gas so as to prevent the liquid level from rising above a given maxr mum irrespective ofthe pressure of liquid tending to leak from the pump. Circulation of oil through the pipes 78, 79 and 80 will cause a downward current of the liquid in the reservoir 47 to keep the bearings 44 and 45 cool and properly lubricated. The cooling of the electric motor 23 is effected by circulating the inert gases through the pipes 83, 84 and 85 by means of the blower. 82.

Stresses within the pump housing caused by internal pressure will be substantially balanced by the opposing external pressure 0 the immersing liquid. 7

This case is a continuation of certain subject matter taken from our copending ap-' plication No. 77,699, filed Dec. 26, 1925 and M) having relatively movable and stationary 1 members between which leakage tends to occur, means for sub ect1ng all portions of said members to an external fluid pressure. and

means for automatically increasing said eX- v te-rnal pressure in accordance with an increase in the amount of said leakage.

2. In a pumping system, a liquid pump having relatively movable and stationary members, meansfor subjecting all portions of said members to an external fluid pressure, and means for automatically maintaining said external fluid at a pressure at least as great as the maximum pressure of the fluid tending to leak from the system.

3. In a pumping system, a liquid pump having relatively movable and stationary members-and provided with inlet and outlet passages, means for immersing adjacent exterior portions of said members in a mass of liquid, means containing a gaseous medium for exerting pressure on the surface of said liquid, and means for automatically controlling said pressure in accordance with the level of the liquid immersing said members.

4.'In a pumping system, a liquid pump including submergmg saidpump in liquid under pressure, andmeans for varying the pressure of said liquid in accordance with variations in the pressure of the liquid within the system.

5. In a pumping system, a liquid ump including a housing, means for comp etely submergmg said pump in liquid under pressure, and means for automatically varying the pressure of said liquid in accordance with variations in the pressure of the oil within the system.

6. In a liquid pumping system, a pump having relatively movable members, an enclosure for external portions ofsaid mem bers containing a gaseous medium, and means for automatically increasing the ressure of said gaseous medium in accor ance with the amount of liquid leakage tendin to occur from the pump between said mem rs.

7. In an oil pumping system for pumping oil above atmospheric pressure, a liquld pump having relatively stationar and movab'le members and provided wit inlet and outlet passages, said movable member including a rotatable shaft extending into said member, a bearing for said shaft adjacent said stationary member, a reservoir secured to said stationary member to surround said bearing, means for by-passing oil from said outlet thru said reservoir to lubricate said bearing, and means for exerting a pressure above atmospheric upon the liquid in said vreservoir whereby loss of oil from the system is arrested.

8. In a pumping system, a pump adapted to receive relatively hot liquid, means for immersing certain exterior portions of said pump in a mass of liquid to form a liquid seal, and baflie means for minimizing convection currents in said mass of liquid.

9. In a pumping system a pump adapted to receive relatively hot liquid, means for immersing certain exterior portions of said pump in a mass of liquid to form a liquid seal, and heat insulating means within said a housing, means for completely reservoir, and means responsive to the level of the liquid in said reservoir to control the flow of gas from said source to sa1d reservoir in order to maintain said level substantially constant.

11. A pumping device comprising a cal casing, a centrifugal pump-including a housing mounted in the lower portion of said casingand having inlet and outlet openvertiings extending outside said casing, said 1 pump having a vertical shaft, an immersing lkglld in the lower portion of the casing to su merge the pump housing, a reservoir disposed above said pump housing, a bearing for said shaft within said reservoir, a source of gas under pressure external of said casing and communicatin with said casin float means within sai casin for contro ling the supply of gas to said casing from said source, said gas supplied tending to prevent liquid from escaping from said pump housing.

12. In a pumping system, a liquid pump having relatively movable and stationary members and provided with inlet and outlet passages, means including a reservoir for immersing adjacent exterior portions of sa1d members in a mass of 11 uid, means containing a gaseous medium or e'xertin pressure on the surface of said last name quid, means supplyingthe gaseous medium under pressure to said last mentioned means,

and means responsive to the level'of the liqaid in said reservoir to control the supplying of said gaseous medium to said second named means.

13. In a high pressure pumping system,

a liquid pump having relatively movable'l and stationary members between which leakage tends to occur, means surrounding saidmembers for storing accumulated leakage,

means for subjecting said members to an external aseous pressure, and means for automatica 1y increasing said pressure in response to an increase in the quantity of accumulated leakage.

14. In a high" pressure li uid pumping system, a liquid pump having relatively movable and stationary members, means for enclosing adjacent portions of said members and for storing liquid leakage tending to occur between said members, an external tank containing gas under pressure relative- 1y high compared to the pressure of liquid within the system, ineansconnecting said tank and enclosing means for introducing as into said ena-losing: means, and means for controlling the introduction of gas into the enclosing means from said tank Whereby said ad acent portions of sa1d members may be opposed by a pressure approximating the pressure of liquid within the pump at the point of leakage.

In testimony whereof we have hereunto set our hands.

ROYAL E. FRIGKEY. WVILLIAM ROBERT. LAYNE.

Images