US2113116A - Regenerative turbine pump - Google Patents

Description

.April 5, 1938. J.-o. M MILLAN I REGENERATIVE TURBINE PUMP s Sheets-Sheet 1 1 Filed April 9, 1955 3 W McMzZZaz;

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REGENERATIVE TURBINE PUMP I 3Sheets-Sheet 3 Filed April 9, 1935 0. McMillan ll Ml" [m lllll Patented Apr. 5, 1938 UNlTED STATES-Q" PATENT- OFFICE 2,113,116" REGENERATIVE TURBINE PUMP James 0. McMillan, Wichita, Kans;

Application April 9, 1935, Serial No. 15,486

1 Claim. (01. 103-96) This invention relates to pumps and more particularly to regenerative pumps and is a construction capable of pumping a, mixture of water and air at the same time to as high a pressure head with one impeller as. will the commonly known multiple stage centrifugal pump. It is of thetype having a casing provided with an inlet opening and outlet opening for receiving and discharging either liquid or liquid and air by in the action of a rotor of the single cone or double cone type with a multiplicity of enclosed vanes leaning in the direction of rotation, impinging against the free liquid in the channels of the pump and carrying the fluid therein with Operation of the pump is aided by kinetic energy, centrifugal force and tangential force, the

combined action thereof resulting in a helical or spiral course or travel of, the fluid to cause a regenerative action or repeated impulses imparted to the particles of fluid as it travels through the channels.

One object of this invention is to improve this .type of pump as to structure, efficiency and vol- 25 ume based on the discovery that if the raceways are properly curved and placed at right angles to the axis and at an angle to the rotor, the helical path taken by the fluid and the pressure head will be increased.

30 A second object of my invention is to provide :1 double cone or triangular rotor having two channels sealed one from the other to increase the volume, to balance the rotor load, a d to prevent the impeller from becoming air bound :3 by providing sucha rotor that one side may pump liquid and the other side may pump air.

A third object is to provide in a, pump of the general character stated, a chamber in which the liquid and air arelseparated and in which the liquid, or a portion of it, is revolved in the direction opposite to rotation of the rotor and the travelling fluid in the channels, and to return a portion of the water into the rotor chamber to H) maintain a seal.

an impeller in which the channels and vanes are positioned at zones remote to the axis and have means for adjustment and increasing the cam pacity.

A further object is to provide an impeller in which the vanes lean in the direction of rotation and are otherwise angular to cause the fluid to travel in a more pronounced spiral path .to in- 55 crease the pressure head. This construction Another object of the invention is to provide makes it possible to cast or die cast the impeller of bronze or other similar material.

Additionally, I aim to provide an impeller preferably having two raceways .with means for ad-- justmentwhile the pump is in operation to com- 5 pensate for wear, to provide means for adiustment totake up wear in the raceways independently of the impeller, to provide such a pump with interchangeable and renewable raceway liners in which the fluid raceways are sealed one 10 from the other, and to provide a pump of this type in which one of the passageways may be used for low pressure and the other for high pressure to make a two stage pump for high pressure duty.

Various additional objects and advantages will ill become apparent from a consideration of the description following taken in connection with accompanying drawings illustrating an operative embodiment.

In said drawings:

Figure 1 is a substantially central, longitudinally sectionalview through one form of pump according to my invention;

Figure 2 is a vertical, substantially central cross sectional view through said pump;

Figure 3 is a fragmentary side elevation of the impeller;

Figure 4 is a cross sectional view taken on the line 44 of Figure 3;

Figure 5 is a. detail view of the combination check valve and strainer employed, being partly in side elevation and partly in section;

Figure 6 is a view similar to Figure 3 but the vanes thereof being disposed at the opposite anl 3 Figure 7 is a section taken on the line 'l-| of Figure 6; v

Figure 8 is a central, longitudinalsectional view through a modified form of pump;

Figure 9 is a section taken on the line 8-9 40 of Figure 8, and

Figure 10 is a sectional view taken on the line Ill-10 of Figure 9.

Referring specifically to the drawings wherein like reference characters designate like or 5 corresponding parts throughout the difierent views, and first to the form of Figs. 1 to 7, l designates the pump casing having a removable cover 2 bolted at 2 to one side thereof, which casing encloses an impeller 3 between liners l and 5. Said liners 4 and 5 have annular, inwardly extending portions 6 and 'I enclosing the impeller and provided with raceways 6' and I communieating with a common inlet 8, and a common radial outlet 9. Said raceways are blocked or sealed off betweenthe inlet and outlet by a solid portion iii of said portions 6 and I.

Said impeller or rotor 3 is mounted on a tapered portion ll of a shaft l2 and'held rigidly in place by a nut l3 screwed to the shaft. In turn, shaft I2 is mounted on double row ball bearing devices l4 and l5 and sealed by rotary shaft seals l6 and I1 against seats [8 and I3 through the agency of expansive springs and 2| surrounding the shaft. Adjusting nuts 22 and 23 maintain the impeller 3 in proper spacedrelation'with respect to the liners 4 and 5 to prevent a'ctu'almetal to metal contact and its undue wear. A spring washer 24 between bearing device l4 and nut 22 permits of shaft expansions and contractions. The mounting parts for said shaft are disposed within tubular extensions l and 2* of the casing and cover and lubricant is. supplied to the shaft and other working parts, preferably to maintain a bath, by introduction through openings normally covered by screw plugs I and 2 Specifically, the impeller rotor 3 is of the double cone, triangular or wedge shape at the periphery as shown and intimately contacts with walls of the portions 6 and l inwardly of the raceways. The impeller vanes are on opposite sides of rotor 3, extending generally parallel to shaft I2 and designated 21. Said vanes 2l slant in the direction of rotation to the extent of 45 and the faces thereof are also 45 to a line perpendicular to the shaft I2. The base walls of the raceways 6 and I are preferably semi-circular and the spaces between adjacent blades or vanes 21 have their base walls substantially semi-circular but preferably flattened slightly at 21'. These vanes,

raceways and spaces are designed substantially as described so as to cause the fluid to describe a path of travel approaching a helical or spiral path in the impeller'channels or spaces and the raceways, the object being to cause the fluid ahead to dip or return back into the impeller vanes and receive a plurality of impulses to increase the pressure head.

The impeller has grooves 25 engaged by sealing rings or packing 26 of the liners 4 and 5 to prevent radial leakage or inward seepage of fluid.

Said blades 21 preferably have their backs more pronouncedly tapered than their fronts to prevent the formation of eddies and the curved base walls of the spaces or channels between the vanes 21 also prevent the formation of eddies.

In pumping a mixture of air and water, it-is preferable to connect an air inlet to only one side or one raceway near the-inlet so that the impeller may at all times be water sealed and prevented also from becoming air bound. As a further precaution, an air separating chamber 29 is provided in the outlet 3. This chamber 29 has its wall round with its axis parallel to the axis of shaft l2 and hence it causes the water to form a whirlpool in which a portion of the water will be returned to the vanes 21 to perfect and maintain a water seal while pumping a mixture of water-and air. The water in said chamber 29 revolves in the opposite direction t9 the impeller and thus releases the air at the outlet and a portion of the water is returned to the impeller 3 to ,displace the air which may have remained between the blades 21.

To compensate for corrosion, erosion and wear,

the raceways 4 and 5 are interchangeable and renewable. They are also adjustable for wear independently of the impeller and while the pump is in operation. This adjus ment is accomplished byremoving screw plugs 30 and adjusting screw studs 3| by means of a screw driver engaged with key-ways or kerfs 3| thereof.

line, usually but not necessarily a 45 angle, and

raceways to match this angle causes the fluid to be acted upon by centrifugal and tangential forces, the centrifugal force causing the fluid to follow the curved channels and raceways to return the fluid to the blades at the point nearest the axis to receive additional impulses, the inclination of any matter moving in a circlebeing to fly radially from the center of rotation to the extreme point of the periphery. The fluid-is encased and trapped in:the channels of the rotor 3 and the raceways 6' and l and the resultant forces cause the fluid to be deflected at right angles and downwardly to be returned to the impeller blades 21 where the blades give it added impetus and a succession of such impetuses assists in the two forces mentioned in creating a growing pressure head as the liquid again and again receives kinetic energy from the impeller 3. This efficient action of the impeller is due to a large extent to the tapered impeller with its tapered channels, blades inclined in the directionof rotation, raceways on an angle to match the channels of the tapered impeller to cause the fluid to be acted upon by centrifugal force at the point most remote from the axis of the impelling vanes.

The efllciency of the pump is materially increased by the balanced wedge type of the impeller.

Various changes may be resorted to within the spirit and scope of the invention, for instance to dispose the blades or vanes 21 and the channels at angles greater or less than that set forth.

I may also dispose .the blades or vanes of the impeller as designated 21' in Figs. 6 and '7 at the opposite angles to those described so that the pump will operate in the reverse direction to that described, the other pump parts corresponding to such reversal.

- As shown in Figs. 2 and 5, I may employ a novel combined check valve and strainer combination at the intake or suction end of the pump to keep the water from falling back into the well or source of supply and to protect the impeller and parts from coarse sand and other particles. This device has a casing 32 having an inlet at 33 in A pipe 36 connects casing 32 to inlet 3 of the pump, such pipe communicating with a chamber 31 within the casing which communicates with line with a removable, tubular screen 34, held in place by a screw plug 35 in one end of casing 32.

inlet 33 and the screen chamber through a valve Q seat 38. Said valve'seat is normally covered by' a check valve 39, removably secured to a stem by nuts 40 and washers 4|, the upper end of the stem being slidably telescoped in 9. depending tube 42 of a removable screw closure or plug 43 for an opening of casing'32 through which the, valve and valve seat are applicable and remot -fable. Strainer or screen 34 is removable for cleaning.

Instead of the vanes 21, raceways and channels being provided on two sides of an impeller, they may be provided on one side only, as in the form of Figs. 8, 9, and 10. Specifically, there are .two raceways and two sets of blades, the outlet of one raceway being connected to the inlet of the .next one to form a two-stage pump. In this form, a casing 44 is used having an inlet 45 and outlet 46. The combined check valve and strainer of Figs. 2 and 5 may be connected to inlet 45 if-desired. On one side of casing 44 is a side plate 46 removably bolted in place at 41. Within the casing, an impeller 48 is disposed being mounted on a shaft 49 in the same manner in which impeller 3 is mounted on shaft l2, and said shaft 49 in casing 44 and side plate 46 being mounted in the identical manner in which the aforesaid shaft 12 is mounted. Casing 44 has an interior fluid raceway 50 which is semicircular in cross section and extends more than 360 around the casing, thus being spiral or substantially so. (Jo-acting with such raceway 50 are vanes 5| and channels or spaces 52, identical in structure and arrangement to the vanes 21 and channels or spaces between them, being however, arranged in a path more than 360 so as to correspond with the raceway 50.- Raceway 5!! discharges at 5! into the outlet 46. By reason of the construction last described, the impeller 48 is impelled by the fluid almost two revolutions before being discharged so as to increase the pressure head. 7

If desired, the blades or vanes 21, 21', and SI, instead of being integral with the parts carrying them, may be initially separate and welded in place. These separate blades or vanes may be made of very thin sheet metal. Such thin having its inner wall curved about an axis sub-' stantially parallel to the longitudinal axis of the casing, a shaft journalled longitudinally in said casing, a peripherally wedge-shaped impeller on said shaft, liners disposed one on each side of said impeller, each inclined face of said impeller having channels, blades in said channels inclined in the direction of rotation and disposed at an angle to the axis of the impeller, said liners having portions jointly surrounding the periphery of the impeller and provided with raceways opposite the respective channels and communicating through said portions with said outlet chamber, and a closure at said open side of the casing abutting one of said liners and secured to the casing, said side wall' and closure having tubular outward extensions disposed about said shaft provided with interior shoulders, seat members for said shaft located in said.

extensions and abutting said shoulders, seal devices about the shaft engaging said impeller and said seat member's, expansive springs about the shaft engaging said impeller and said seal devices, said impeller having a tapered fit on said shaft with the taper flaring in a direction away from said closure, and screw elements on said closure operable from the exterior of the pump and against one of the liners to move the same and adjacent parts to take up wear.

JAMES O. MCMILLAN.

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