US1979621A - Balanced turbulence pump - Google Patents

Balanced turbulence pump Download PDF

Info

Publication number
US1979621A
US1979621A US652675A US65267533A US1979621A US 1979621 A US1979621 A US 1979621A US 652675 A US652675 A US 652675A US 65267533 A US65267533 A US 65267533A US 1979621 A US1979621 A US 1979621A
Authority
US
United States
Prior art keywords
fluid
pump
impeller
channel
balanced
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US652675A
Inventor
Hollander Aladar
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Priority to US652675A priority Critical patent/US1979621A/en
Application granted granted Critical
Publication of US1979621A publication Critical patent/US1979621A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04DNON-POSITIVE-DISPLACEMENT PUMPS
    • F04D5/00Pumps with circumferential or transverse flow
    • F04D5/002Regenerative pumps
    • F04D5/003Regenerative pumps of multistage type
    • F04D5/006Regenerative pumps of multistage type the stages being axially offset
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04DNON-POSITIVE-DISPLACEMENT PUMPS
    • F04D5/00Pumps with circumferential or transverse flow
    • F04D5/002Regenerative pumps
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05DINDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2260/00Function
    • F05D2260/30Retaining components in desired mutual position
    • F05D2260/34Balancing of radial or axial forces on regenerative rotors

Definitions

  • a fluid pressure increasing in magnitude from the fluid inlet passage to the fluid discharge passage i will be created, as for example, at the entrance of the fluid inlet passage into the fluid channel, the fluid pressure may be zero, while at the discharge outlet the fluid pressure may be 100 lbs.
  • the fluid pressures exert unequal forces lli against substantially the entire periphery of the impeller.
  • the greatest force exerted against the impeller by the fluid pressure is in the vicinity of the discharge passage, which force acts to displace the impeller toward the opposite or inlet W side of the pump casing, as in.
  • the fluid pressure may be considerably below zero or at best, very little above zero, and thus is powerless to counteract the far greater force acting upon the opposite side of the impeller, and there- 26 fore, the impeller is continuously displaced.
  • The] displacement of the impeller causes a relatively. severe bending moment to be placed in the im-' peller shaft, which in turn causes undue wear in the shaft bearings, but even more serious,
  • a further object is to provide a balanced twostage turbulence pump with two fluid channels, each having a single separator member formed therein, and for arranging the separator of onechannel at 180 from the separator of the other 543 channel, whereby the unbalanced forces acting against one impeller, will act to counterbalance the unbalanced forces acting against the other impeller.
  • a further object is to provide a balanced turbulence pump with a plurality of fluid channels
  • Figure 1 illustrates a sectional view taken substantially in the plane of line 1--1 of Fig. 2, of a 'two stage balanced turbulence pump and in 'which view a portion of .the impeller has been broken away so as to more clearly show the fluid channel.
  • Figure 2 illustrates a sectional view taken substantially in the plane of line 2-2 of Fig. 1.
  • Figure 3 illustrates a side elevation of the pump together with the arrangement of the system of ducts for serially communicating the two stages.
  • Figure 4 illustrates a side elevation of the pump showing the arrangement of ducts or manifolds for connecting the two channels in parallel.
  • the fluid pressure or head generated by a turbulence pump is proportional to the length of the fluid channel, and as one of-the important features of this type of pump is its ability to generate relatively high pressures, it is desirable to make the fluid channel as long as possible.
  • the maximum length of fluid channel may be obtained by providing a single channel having a length equal to its circumference, less the length necessary for the separator, but a turbulence pump having a single fluid channel and separator is undesirable due to the unbalanced forces acting against the impeller.
  • two single channel turbulence pumps so that their separators are located diametrically opposite, and their impellers mounted in relatively close relation upon a single shaft, then such a pump will be substantially balanced.
  • such a double turbulence pump is illustrated and may briefly include a casing 30 formed of covers 31 and 32, and a diaphragm 33 suitably fastened together as by,
  • the cover 31 may be provided with a single fluid channel 35, a separator 36, an appropriate inlet passage 37, and an appropriate discharge passage 38, while the cover 32 may likewise be provided with a single fluid channel 89, a separator 40, an appropriate inlet passage 41, and an appropriatedischarge passage 42.
  • Each cover may be provided with a suitable stuffing box 43, and a bore 44 through which the shaft 45 may be operatively mounted.
  • the separators 36 and i0 are provided to form an effective fluid seal with the periphery and side blades of their respective rotors and to thus partition the inlet end of the channel from the discharge end thereof. It will be understood that the separators do not form such a close flt with the rotors as to prevent the free rotation thereof but are sufliciently close to effectively seal the inlet from the discharge passages between'which the separators are mounted.
  • the diaphragm may be provided with a bore 46 which may act as a bearing for the shaft 45, and also to prevent leakage between the two stages of the pump.
  • a portion of each fluid channel and its separator may be formed for its respective cover member.
  • a rotor or impeller 47 ' may be operatively mounted in each cover member, and each impeller may be suitably mounted upon shaft 45.
  • Each side face of the impeller adjacent the periphery thereof may be provided with grooves so as to form fluid impelling blades and contiguous therewith fluid sealing surfaces 20 and 21.
  • the impeller fluid sealing surfaces may form close working fits with corresponding fluid sealing faces 22 and 23 formed in the casing.
  • Turbulence pumps have been designed with a casing arranged to provide two fluid channels of substantially half a circle each and divided by oppositely disposed separators through which the bladed periphery of a single impeller travels.
  • the maximum pressure which this type of pump may deliver is proportioned to the length of its fluid channel, and it follows that for pumps of equal diameter the one having two oppositely disposed fluid channels will have a maximum effective fluid head of only one-half that of a turbulence pump having a single fluid channel which extends entirely around the casing excepting for the space occupied by the separator.
  • the fluid pressure created in the single channel will be substantially twice as great as in the double channel pump. However, substantially only onehalf as much fluid will be pumped by each stage.
  • the same volume of fluid may be delivered at twice the pressure as would be the case with the single impeller double channel pump.
  • single channel turbulence pumps may operate to deliver the fluid at higher pressures, it
  • a three stage turbulence pump may be balanced by spacing the separators 120 apart, and a four stage turbulence pump by spacing the separators 90 apart.
  • a multistage turbulence pump maybe balanced by angularly spacing the separators at equal distances around the pump structure.
  • the two pumping stages of the turbulence pump illustrated in Figures 1 and 2 may be connected in parallel as by an arrangement of ducts as illustrated in Fig, 4, or may be connected in series by the arrangement of ducts as illustrated in Fig. 3.
  • the two stages may be communicated in parallel as, for example, by providing an inlet manifold 26 arranged to communicate the inlet passages 37 and 41 of the respective channels with a source of fluid supply and a discharge manifold 27 arranged to communicate the two discharge passages 38 and 42 with a discharge pipe, not shown.
  • the system of ducts as illustrated in Fig. 3, for connecting the two pumping stages in series may include an inlet duct 48 for communicating the inlet passage 37 with a source of fluid supply, a transfer duct 49 for communicating the dis charge passage 38 of the first stage with the inlet passage 41 .of the second stage, While the discharge passage 42 may communicate with the final discharge duct 50.
  • casing means having a plurality of fluid channels arranged in different planes, a single separator for each channel positioned to separate the inlet from the outlet ends of their respective channels and arranged in equally spaced angular relation, an impeller for each fluid channel arranged to form an effective fluid seal with the separator thereof, and said casing having appropriate inlet and outlet passages for each channel.
  • casing means having a flrst and second stage fluid channel arranged in different planes, 9. single separator for each channel located in said casing 180 degrees apart and each 01' said separators arranged to partition the inlet from the outlet ends of their respective channels, an impeller for each fluid channel, fluid impelling means carried by each impeller and arranged to form with its respective separator an eflective fluid seal, said casing having appropriate inlet and outlet passages for each fluid channel, and duct means for serially communicating said casing inlet and outlet passages.
  • casing means having a plurality of fluid channels arranged in difl'erent planes, a single separator for each channel positioned to separate the inlet from the outlet ends of their respective channels and arranged in equally spaced angular relation, an impeller for each fluid channel and each impeller having fluid impelling means arranged to ill form with its respective separator aneflective fluid seal, said casing having appropriate inlet and outlet passages .tor each fluid channel, and duct means for serially communicating said casing inlet and outlet passages.
  • casing means having a plurality of fluid channels arranged in dinerent planes, a single separator for each channel positioned to separate the inlet from the outlet ends of their respective channels and arranged in equally spaced angular relation, an impeller for each fluid channel and each impeller having fluid impelling blades, arranged to form with its respective separator an effective fluid seal, said casing having appropriate inlet and outlet passages for each fluid channel, an

Description

Nov. 6, 1934. A. HOLLANDER BALANCED TURBULENCE PUMP Filed Jan. 20, 1933* atented Nov. 6, 1934 UNITED STATES PATENT OFFICE This invention relates to a turbulence pump in which the unbalanced forces acting upon the impeller to set up a bending moment in the impeller shaft, are counterbalanced-or neutralized.
ii In a turbulence pump of the type in which the outer casing is provided with a smooth fluid channel within which the blades of the impeller travel, a fluid pressure increasing in magnitude from the fluid inlet passage to the fluid discharge passage i will be created, as for example, at the entrance of the fluid inlet passage into the fluid channel, the fluid pressure may be zero, while at the discharge outlet the fluid pressure may be 100 lbs. Thus the fluid pressures exert unequal forces lli against substantially the entire periphery of the impeller. The greatest force exerted against the impeller by the fluid pressure, is in the vicinity of the discharge passage, which force acts to displace the impeller toward the opposite or inlet W side of the pump casing, as in. this vicinity the fluid pressure may be considerably below zero or at best, very little above zero, and thus is powerless to counteract the far greater force acting upon the opposite side of the impeller, and there- 26 fore, the impeller is continuously displaced. The] displacement of the impeller causes a relatively. severe bending moment to be placed in the im-' peller shaft, which in turn causes undue wear in the shaft bearings, but even more serious,
33d makes it practically impossible to maintain the stufling boxes fluid tight. This is especially serious when the pump is to be used as a vacuum pump, as unless the stufling boxes are maintained fluid and vapor tight, air will filter in through the 15 stufflng boxes and cause vapor binding of the pump, and even though the pump should not lose its prime, the infiltration of air through the stuffing boxes, will materially reduce the operating emciency thereof.
the above set forth inherent defects of a turbulence pump, by providing means for counterbalancing or neutralizing the unbalanced forces of the impeller.
A further object is to provide a balanced twostage turbulence pump with two fluid channels, each having a single separator member formed therein, and for arranging the separator of onechannel at 180 from the separator of the other 543 channel, whereby the unbalanced forces acting against one impeller, will act to counterbalance the unbalanced forces acting against the other impeller.
A further object is to provide a balanced turbulence pump with a plurality of fluid channels,
It is an object of this invention to overcome each having a single separator member formed therein, and for angularly spacing each of the separators an equal amount with relation to the other separators, and for providing appropriate duct means communicating all of the fluid channels in parallel, or for providing an appropriate duct means for serially communicating the fluid channels.
Other objects and advantages of the invention will become apparent as the nature of the same is more fully understood from the following description and accompanying drawing wherein is set forth what is now considered to be a preferred embodiment. It should be understood, however, that this particular embodiment of the invention is chosen principally for the purpose of exempliflcation, and that variations therefrom in details of construction or arrangement of parts may accordingly be effected and yet remain within the spirit and scope of the invention as the same is set forth in the appended claims.
In the drawing:
Figure 1 illustrates a sectional view taken substantially in the plane of line 1--1 of Fig. 2, of a 'two stage balanced turbulence pump and in 'which view a portion of .the impeller has been broken away so as to more clearly show the fluid channel.
Figure 2 illustrates a sectional view taken substantially in the plane of line 2-2 of Fig. 1.
Figure 3 illustrates a side elevation of the pump together with the arrangement of the system of ducts for serially communicating the two stages.
Figure 4 illustrates a side elevation of the pump showing the arrangement of ducts or manifolds for connecting the two channels in parallel.
The fluid pressure or head generated by a turbulence pump is proportional to the length of the fluid channel, and as one of-the important features of this type of pump is its ability to generate relatively high pressures, it is desirable to make the fluid channel as long as possible. The maximum length of fluid channel may be obtained by providing a single channel having a length equal to its circumference, less the length necessary for the separator, but a turbulence pump having a single fluid channel and separator is undesirable due to the unbalanced forces acting against the impeller. However, by arranging two single channel turbulence pumps so that their separators are located diametrically opposite, and their impellers mounted in relatively close relation upon a single shaft, then such a pump will be substantially balanced.
In Figures 1, 2, 3 and 4, such a double turbulence pump is illustrated and may briefly include a casing 30 formed of covers 31 and 32, and a diaphragm 33 suitably fastened together as by,
means of bolts 34. The cover 31 may be provided with a single fluid channel 35, a separator 36, an appropriate inlet passage 37, and an appropriate discharge passage 38, while the cover 32 may likewise be provided with a single fluid channel 89, a separator 40, an appropriate inlet passage 41, and an appropriatedischarge passage 42. Each cover may be provided with a suitable stuffing box 43, and a bore 44 through which the shaft 45 may be operatively mounted. The separators 36 and i0 are provided to form an effective fluid seal with the periphery and side blades of their respective rotors and to thus partition the inlet end of the channel from the discharge end thereof. It will be understood that the separators do not form such a close flt with the rotors as to prevent the free rotation thereof but are sufliciently close to effectively seal the inlet from the discharge passages between'which the separators are mounted.
The diaphragm may be provided with a bore 46 which may act as a bearing for the shaft 45, and also to prevent leakage between the two stages of the pump. In each side face of the diaphragm a portion of each fluid channel and its separator may be formed for its respective cover member.
A rotor or impeller 47 'may be operatively mounted in each cover member, and each impeller may be suitably mounted upon shaft 45.
Each side face of the impeller adjacent the periphery thereof may be provided with grooves so as to form fluid impelling blades and contiguous therewith fluid sealing surfaces 20 and 21. When the impellers are mounted in the casing, the impeller fluid sealing surfaces may form close working fits with corresponding fluid sealing faces 22 and 23 formed in the casing.
Turbulence pumps have been designed with a casing arranged to provide two fluid channels of substantially half a circle each and divided by oppositely disposed separators through which the bladed periphery of a single impeller travels. However in turbulence pumps, speeds andsizes being equal, the maximum pressure which this type of pump may deliver is proportioned to the length of its fluid channel, and it follows that for pumps of equal diameter the one having two oppositely disposed fluid channels will have a maximum effective fluid head of only one-half that of a turbulence pump having a single fluid channel which extends entirely around the casing excepting for the space occupied by the separator.
As the fluid channel of each stage is substantially twice as long as in the pump above referred to considering pumps 01' equal diameters, the fluid pressure created in the single channel will be substantially twice as great as in the double channel pump. However, substantially only onehalf as much fluid will be pumped by each stage. By providing two impellers and two separate single .channels, the same volume of fluid may be delivered at twice the pressure as would be the case with the single impeller double channel pump. As single channel turbulence pumps may operate to deliver the fluid at higher pressures, it
is therefore, of greater importance to provide whereby the unbalanced forces acting upon one impeller are balanced by the unbalanced forces acting upon the other impeller. Likewise, a three stage turbulence pump may be balanced by spacing the separators 120 apart, and a four stage turbulence pump by spacing the separators 90 apart. In other words, a multistage turbulence pump maybe balanced by angularly spacing the separators at equal distances around the pump structure.
The two pumping stages of the turbulence pump illustrated in Figures 1 and 2 may be connected in parallel as by an arrangement of ducts as illustrated in Fig, 4, or may be connected in series by the arrangement of ducts as illustrated in Fig. 3.
As may be observed in Fig. 4, the two stages may be communicated in parallel as, for example, by providing an inlet manifold 26 arranged to communicate the inlet passages 37 and 41 of the respective channels with a source of fluid supply and a discharge manifold 27 arranged to communicate the two discharge passages 38 and 42 with a discharge pipe, not shown.
The system of ducts as illustrated in Fig. 3, for connecting the two pumping stages in series, may include an inlet duct 48 for communicating the inlet passage 37 with a source of fluid supply, a transfer duct 49 for communicating the dis charge passage 38 of the first stage with the inlet passage 41 .of the second stage, While the discharge passage 42 may communicate with the final discharge duct 50.
When the two s age turbulence pump is connected in series as in Fig. 3, it will operate to deliver substantially one-halfas-much fluid at twice the pressure as when the two stages are connected in parallel, by the arrangement of ducts as illustrated in Fig. 4.
Having fully disclosed the invention, it is not to be limited to the details herein set forth, but the invention is of the full scope of the appended claims.
I claim:
1. In a balanced turbulence pump, casing means having a plurality of fluid channels arranged in different planes, a single separator for each channel positioned to separate the inlet from the outlet ends of their respective channels and arranged in equally spaced angular relation, an impeller for each fluid channel arranged to form an effective fluid seal with the separator thereof, and said casing having appropriate inlet and outlet passages for each channel.
2. In a balanced two stage turbulence pump, casing means-having a flrst and second stage fluid channel arranged in different planes, 9. single separator for each channel located in said casing 180 degrees apart and each 01' said separators arranged to partition the inlet from the outlet ends of their respective channels, an impeller for each fluid channel, fluid impelling means carried by each impeller and arranged to form with its respective separator an eflective fluid seal, said casing having appropriate inlet and outlet passages for each fluid channel, and duct means for serially communicating said casing inlet and outlet passages.
3. In a balanced multistage turbulence pump, casing means having a plurality of fluid channels arranged in difl'erent planes, a single separator for each channel positioned to separate the inlet from the outlet ends of their respective channels and arranged in equally spaced angular relation, an impeller for each fluid channel and each impeller having fluid impelling means arranged to ill form with its respective separator aneflective fluid seal, said casing having appropriate inlet and outlet passages .tor each fluid channel, and duct means for serially communicating said casing inlet and outlet passages. a I
l. In a balanced turbulence pump, casing means having a plurality of fluid channels arranged in dinerent planes, a single separator for each channel positioned to separate the inlet from the outlet ends of their respective channels and arranged in equally spaced angular relation, an impeller for each fluid channel and each impeller having fluid impelling blades, arranged to form with its respective separator an effective fluid seal, said casing having appropriate inlet and outlet passages for each fluid channel, an
tor and said casing having appropriate fluid inlet and outlet passages for each fluid channel.
ALADAR HOILANDER.
US652675A 1933-01-20 1933-01-20 Balanced turbulence pump Expired - Lifetime US1979621A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US652675A US1979621A (en) 1933-01-20 1933-01-20 Balanced turbulence pump

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US652675A US1979621A (en) 1933-01-20 1933-01-20 Balanced turbulence pump

Publications (1)

Publication Number Publication Date
US1979621A true US1979621A (en) 1934-11-06

Family

ID=24617707

Family Applications (1)

Application Number Title Priority Date Filing Date
US652675A Expired - Lifetime US1979621A (en) 1933-01-20 1933-01-20 Balanced turbulence pump

Country Status (1)

Country Link
US (1) US1979621A (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2662479A (en) * 1950-11-03 1953-12-15 Bendix Aviat Corp Turbine pump or motor
US2834517A (en) * 1954-03-15 1958-05-13 John J Townsley Rotating propellant tank having baffle means for directing propellant to outlets
US3127839A (en) * 1961-12-11 1964-04-07 Gen Electric Clothes washer with improved turbine type pump
US3476051A (en) * 1967-12-19 1969-11-04 Lucas Industries Ltd Liquid pumps
US3477636A (en) * 1968-04-04 1969-11-11 Gen Electric Balancing of gas pressure forces in multi-stage regenerative compressors
US3915589A (en) * 1974-03-29 1975-10-28 Gast Manufacturing Corp Convertible series/parallel regenerative blower
DE2602499A1 (en) * 1975-07-24 1977-02-10 Roth Co Roy E MULTI-STAGE PUMP
DE3427112A1 (en) * 1984-07-23 1986-01-23 Friedrich 8541 Röttenbach Schweinfurter SIDE CHANNEL PUMP WITH FORCE COMPENSATION
WO1992010681A1 (en) * 1990-12-15 1992-06-25 Dowty Defence And Air Systems Limited Regenerative pump
US20110229308A1 (en) * 2009-01-09 2011-09-22 Sulzer Pumpen Ag Centrifugal pump having an apparatus for the removal of particles

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2662479A (en) * 1950-11-03 1953-12-15 Bendix Aviat Corp Turbine pump or motor
US2834517A (en) * 1954-03-15 1958-05-13 John J Townsley Rotating propellant tank having baffle means for directing propellant to outlets
US3127839A (en) * 1961-12-11 1964-04-07 Gen Electric Clothes washer with improved turbine type pump
US3476051A (en) * 1967-12-19 1969-11-04 Lucas Industries Ltd Liquid pumps
US3477636A (en) * 1968-04-04 1969-11-11 Gen Electric Balancing of gas pressure forces in multi-stage regenerative compressors
US3915589A (en) * 1974-03-29 1975-10-28 Gast Manufacturing Corp Convertible series/parallel regenerative blower
DE2602499A1 (en) * 1975-07-24 1977-02-10 Roth Co Roy E MULTI-STAGE PUMP
DE3427112A1 (en) * 1984-07-23 1986-01-23 Friedrich 8541 Röttenbach Schweinfurter SIDE CHANNEL PUMP WITH FORCE COMPENSATION
EP0170175A2 (en) * 1984-07-23 1986-02-05 Friedrich Schweinfurter Regenerative pump with force balancing
EP0170175A3 (en) * 1984-07-23 1987-06-03 Friedrich Schweinfurter Regenerative pump with force balancing
US4678395A (en) * 1984-07-23 1987-07-07 Friedrich Schweinfurter Regenerative pump with force equalization
WO1992010681A1 (en) * 1990-12-15 1992-06-25 Dowty Defence And Air Systems Limited Regenerative pump
US20110229308A1 (en) * 2009-01-09 2011-09-22 Sulzer Pumpen Ag Centrifugal pump having an apparatus for the removal of particles
US8858157B2 (en) * 2009-01-09 2014-10-14 Sulzer Pumpen Ag Centrifugal pump having an apparatus for the removal of particles

Similar Documents

Publication Publication Date Title
US1979621A (en) Balanced turbulence pump
US2233825A (en) Pump
US1927543A (en) Sealing device
GB1218130A (en) Rotary positive-displace ment gas compressor
US2056553A (en) Pump
US2195174A (en) Pump
US2601828A (en) Centrifugal pump
US2410769A (en) Turbine, turbine type compressor, and the like rotating machine
US2429978A (en) Centripetal-centrifugal pump
US1912452A (en) Balanced multistage centrifugal pump
US2393691A (en) Pumping unit
US3788764A (en) Multi-stage centrifugal pump with means for pulse cancellation
US3718406A (en) Centrifugal pump with integral seal pressure balance
US2027594A (en) Rotary compressor
US1941442A (en) Multistage centrifugal pump
US2300689A (en) Automatic priming pump and the like
US2500227A (en) Liquid pumping unit
US2286522A (en) Centrifugal compressor
US896585A (en) Centrifugal pump.
US1975274A (en) Centrifugal pump impeller
US2662479A (en) Turbine pump or motor
US1949429A (en) Fluid seal
US1456051A (en) Centrifugal pump
US2764945A (en) Pump and liquid shaft seal therefor
US3351272A (en) Vacuum pump