US2215505A - Variable capacity pumping apparatus - Google Patents

Description

Sept. 24, 1940.

- A. HOLLANDER VARIABLE CAPACITY PUMPING APPARATUS 2 Sheets-Sheet 1 Filed June 13. 1958' 34, i AZadar HbZZander INVENTOR ATTORNEY Sept. 24, 1940.

HEAD lN FEET A HOLLANDER 2,215,505

VARIABLE CAPACITY PUMPING APPARATUS Filed June 13,1938 2 Sheets-Sheet .2

550 Ham CAPACITY CURVE- LA [7 200 HEAD- CAPACITY CURVE- SUBMERSIBLE UNIT v IN F'EET HEAD 800 I000 I25 CAPACITY GALLONS PER MINUTE APAcnY cuev V E\ L y fl J 0 HEAD- CAPACITY cuRvz-. y SUBMERSIBLE UNIT FRICTION- SUBMERSIBLE y" DISCHARGE COLIUMN m IN FEET HEAD C l E, I I F 800 I000 CAPACITY- GALLONS PER MINUTE RESERVOIR HElGHT AZcZdar 561 lander INVENTOR W ax @ew/ 4O 6 0 CAPACITY GALLONS PER MINUTE ATTORNEY Patented Sept. 24, 1940 UNITED "STATES I 2,215,505 VARIABLE CAPACITY PUMPING APPARATUS Aladar Hollander, Los Angcles, Calif assignor to Byron Jackson 00., Huntington Park, Calil'., a corporation of Delaware Application June 13, 1938, Serial No. 213,431

Claims. 9 (01. 103-105) This invention relates generally to deepwell centrifugal pumps, and is directed particularly to the provision of a deepwell pump having a plurality of capacities to meet varying pumping I requirements.

It is well known that the capacity of a deepwell centrifugal pump is determined by the static head, the friction head, and the draw-down of the well, and when installed in a well the ca- 0 10 pacity becomes substantially fixed so long as the draw-down remains constant. In many instances, however, the output of a water well is used for different purposes requiring widely varying head and volume characteristics. It is, therefore, a principal object of this invention to provide a deepwell pump the discharge of which is capable of being varied as to head and volume to meet widely different requirements.

This object is accomplished by combining a standard shaft-driven deepwell pump with a submersible motor-pump unit. The relative sizes and capacities of the two pumps may be selected ac cording to the particular conditions encountered.

An instance in which this invention has particular utility is that in which water is required both for irrigation and for domestic use. The former requires a large volume, usually with surface discharge, while the latter requires a higher head but relatively small volume. Under so these conditions a relatively small capacity, subthe lower end of a large capacity shaft-driven deepwell pump. The domestic water supply is furnished by the submersible pump, which dis- 35 charges through the larger pump when the latter is idle, while for irrigation the large pump is operated. A separate inlet from the-well, with inwardly opening check valves, may be provided between the two pumps if desired, to permit in- 0 dependent operation of the larger pump.

The arrangement described above may be modified by mounting the submersible unitin the discharge column of the large pump, if the drawdown of the well at the capacity of the small pump is not great. The relative sizes of the submersible unit and the discharge column of the large pump are such that the former does not interfere with the discharge from the latter. With this arrangement the two pumps are-not so only operable separately, as in the arrangement described above, but may be operated simultaneously to provide a relatively small-volume at high pressure from the submersible unit while the large capacity shaft-driven pump is operating.

55 Many instances of wide variations in head and volume requirements may be met by combining a standard shaft-driven deepwell pump and a submersible motor-pump unit of equal capacity. When connected in end-to-end relation with a 60 separate valved inlet for the upper pump between mersible motor-pump unit may be connected to tion thereof is. unnecessary.

the pumps, ei therpump may be operated singly to deliver a relatively small volume of water at low head, or both pumps may be operated in series to deliver a larger volume at higher head. This arrangement is useful in irrigation when '5 part of the land to be irrigated is below the ground surface and requires only surface discharge, and partof the land is at a higher elevation than the top of the well.

The foregoing are typical examples of the uses 10 to which a standard deep-well pump and a submersible motor-pump may be put when combined in a single well to provide variable capacity to meet widely varying requirements. The manner in which they may be combined will be apparent 18 from the following description, taken in conjunction with the accompanying drawings, wherein: Figure 1 is an elevational view, partly in section, illustrating a small submersible motor-pump 90 unit suspended from the lower end of a shaftdriven deepwell pump of large capacity;

Figure 2 is an elevational view of a modification of the arrangement shown in Figure 1, with the submersible unit mounted in the discharge 001- umn of the large unit; Fig. 3 is an elevational view, partly in section, showing a submersible unit mounted on the lower end of a shaft-driven deepwell pump, the two' pumps being of equal capacity; and

Figs. 4, 5, and 6 illustrate graphically the operating characteristics of the combinations shown in Figs. 1, 2, and 3, respectively. Referring to Fig. 1, a standard shaft-driven deepwell pump is shown as comprising aseries v of pump bowls I connected to the lower end of a discharge column 2 and having impellers mounted on the pump shaft 3 extending to the surface and driven by the motor 4. The usual suction, piece '5 and strainer 6 are mounted below the pump bowls, and connected between the bolting flanges of the suction piece and strainer is the upper, inwardly extending flange of a shell 1. The shell has an upper cylindrical mrtion surrounding the strainer 6, and a lower downwardly .4 tapered portion.

Secured to the lower end of the shell is the discharge piece Ill of a submersible motor-pump unit comprising a series of impeller bowls II, a suction piece l2, a strainer l3, a motor adapter 5 I4, and a submersible electric motor IS. The details of construction of this unit form no part of this invention, and hence a detailed descrip- A plurality of inlets 2| are provided in the lower tapered portion of the shell "I, and inwardly opening check valves 22 are pivotally mounted at 23. in the base of the shell for closing the inlets against outward flow of'fiuid. A strainer 25 is .mounted in the shell between the lower end of I strainer 6 and the base'of the shell, to prevent entrance of large size solids into the submersible unit.

In operation, either pump may be operated singly, depending on the capacity required. The

relatively small capacity submersible unit is "adapted to supply water for domestic use while the large shaft-driven pump is idle. Since the draw-down of the well will be much less when operating the small capacity submersible unit than when operating the large pump, the submersible unit will deliver water at ample pressure for domestic use. During operation of the sub; mersible unit the discharge thereof passes through the idle upper pump, the check valves 22 being held closed by the excessive pressure in the shell I and by gravity. If desired, the valves may be spring-pressedto closed position, as by torsion springs mounted on the pivot pins 23.

When a large amount of water is desired, as for irrigation, the shaft-driven pump is operated. During this operation the check valves swing inwardly and admit well fluid directly from the well into the strainer 6, the inward movement of the valves being limited by the strainer 25 to the dotted-line position shown. The valves when open form a substantially solid protecting wall about the strainer 25 and deflect the water upwardly to strainer I, while at the same time reducing to a minimum the amount of sand tending to enter the screen 25 and thence into the lower pump.

Since the two pumps are driven by separate motors, they'may be driven at different speeds, the speed of each pump being selected to provide most efiicient operation.

In Figure 2 is shown a modification of the arrangement shown in Figure 1, in which a small diametensmall capacity submersible unit for domestic supply is mounted in the discharge column of a large capacity pump. The shaft-driven deepwell pump is of standard construction, except that if desired the discharge column 3| may be extra large to compensate for the space occupied by the submersible unit. The impeller bowls 32, suction piece 33, strainer 34 and motor 35 are of conventional design.

The submersible unit is similar to that shown in Figure 1, and comprises the usual submersible electric motor 38, adapter 39, strainer 40, impeller bowls 4|, discharge piece 42, and column pipe 43. The discharge elbow is formed in a casting 41 resting on the base flange 48 which supports the discharge column 3|.

The submersible motor 38 is connected to a I suitable source of current by a conductor cable 5|. The motor is preferably of the oil-filled, pressure balanced type, the cable 5| being also under equalized internal and external pressures. Inasmuch as the motor is located in the discharge column of the large pump and subjected to the discharge pressure thereof when the latter is operating, the cable 5| is sealed off at the point where it extends through the discharge column 3|. A pothead 52 is provided for this purpose, the conductors in the cable extending through the column 3| in fluid-tight relation thereto and terminating in contact posts on the outer side of the column. A second pothead 53 detachably secured to the exterior of the column contains sockets to receive the contact posts, and is connected to a cable 54 leading to the source of current.

In this form of the invention, as in Figure 1,

either pump may be operated independently of the other in accordance with the demand, the small pump delivering a small volume at a higher head than .the large pump because of the lesser draw-down at small capacity. This form has an advantage over that of Figure 1 in that the submersible unit may be removed from the well without removing the large column and pump.

As mentioned previously this arrangement has another distinctive advantage over that of Figure 1, in that the discharge of the submersible is separate from that of the large pump, and consequently both pumps may be operated simultaneously to deliver water through their respective discharge columns. Since the inlet of the submersible pump is in the large discharge column, the suction pressure of the submersible unit will be relatively high and the discharge pressure thereof will be correspondingly higher than when the submersible unit is operating alone.

Referring now to Figure 3, there is shown a combination of a standard shaft-driven deepwell pump generally designated 60, and a submersible motor-pump unit generally designated 6|. In this case the two pumps are of substantially equal capacity, and either pump may be operated singly to deliver water at relatively low head or the two pumps may be operated simultaneously in series to provide increased head and capacity. A shell 62 similar to the shell 1 of Figure 1 is connected to the lower end of the upper pump, and is provided with inlets 63 and check valves 64, as in Figure 1.

This arrangement is particularly useful in municipal water supply systems, wherein relatively low pressure is required for domestic service and high pressure is required for fire extinguishing. Either of the pumps 60 or 6| when operating alone will deliver sufiicient water and at adequate pressure for domestic use, while for fire extinguishing both pumps may be operated to deliver high pressure water directly from the well to the fire mains.

As stated in the introductory remarks, the combination disclosed in Figure 3 is also well adaptthe point A at the intersection of the pump performance curve and of curve O-A, representing the summation of the static and friction heads, determines the operating point of the large pump under the fixed conditions of draw-down and column pipe friction. Under these conditions approximately 950 gal./min. are delivered against a total head of 250 feet. The small capacity submersible causes only a relatively slight drawdown, represented by D--E, and the friction head C-D is relatively small atasmall capacity. Consequently against a surface pressure of approximately 30 lbs. per sq. in., as represented by B-C, this pump has a capacity of approximately gal./min.

Figure 5, representing the performance of the modification shown in Figure 2, differs from Figure 4 in that the friction curve for the submersible unit is different from that of the large shaft-driven pump because of the separate discharge columns .of diiferent diameters and lengths. The higher friction head due to the small discharge column 43 of Figure 2 is partially offset by the fact that in this arrangement the column 43 is of less length than the main column, and the submersible unit does not discharge through the large pump. Consequently the performance of the submersible unit, as shown in Figure 5, closely approximates that shown in Figure 4.

Figure 6 shows graphically the head-capacity performance of the two pumps of equal size illustrated in Figure 3. The point J on the lower head capacity curve represents the operating point of either pump whenoperated singly with discharge into a reservoir located approximately '75 feet above the mouth of the well. In thiscase the capacity is approximately 530 gallons per minute against a head of 220 feet, as represented by J-K. The. upper head capacity curve is that of the two pumps operating in series, the operating point being indicated at L. When combined, the two pumps have a capacity of about 760 gal./min. against a head of 420 feet, represented at L-M,

thus providing an additional head of 200 feet above the reservoir. I

It will be understood that the foregoing graphs, and particularly the numerical values, are solely by way of example to illustrate typical headcapacity combinations. While I have described three specific examples-of the manner in which a submersible motor-pump unit may be combined with a standard shaft-driven deepwell pump, it will be appreciated that other combinations with different relative capacities maybe provided within the scope bf this invention.

I claim: 1 e

1. Variable capacity deep well pumping appa ratus comprising, in combination: a relatively ground surface and operatively connected to said large-capacity pump; said large capacity pump having an inlet, and means for selectively connecting said inlet directly with the well 'or'with the discharge from said small capacity pump, said connecting means comprising an inlet chamber surrounding said inlet, and having a valved port in the wall thereof and an opening communicating with the discharge end of saidsmall capacity pump, and an inwardly opening check valve adapted to open said port during operation of said large capacity pump to admit well liquid therethrough,,said valve being adapted to close said port during operation of said small capacity pump whereby the discharge therefrom is constrained to flow from said chamber through said large capacity pump and into said discharge column.

2. Deepwell pumping apparatus comprising, in combination: a discharge column extending downwardly within the well from the surface; a

said discharge column, each pump comprising a group of stages connected inseries and including impeller means mounted on'common shafting individual to each of said pumps; each pump having a screened inlet, the inlet of the lower pump communicating directly with the well, and the inlet of the upper pump communicating with an inlet chamber surrounding the same, said inlet chamber having an inwardly opening check valve permitting flow of well liquid into saidchamber during operation of said upper pump but preventing outward. flow from the chamber to the well during operation of said lower pump; said lower pump having a screened outlet communicating with said inlet chamber; and means for operating said pumps independently of each other, said operating means comprising a submersible electric motor suspended from said lower pump and having its drive shaft operativelyconnected to the impeller shaft of said lower pump, and a prime mover at the surface of the well and drive means extending from said prime mover downwardly within the well into operative driving relation with the impeller shaft of said upper pump.

3. Deep well pumping apparatus comprising, in I combination: a pump discharge column extending downwardly within the well from the surface; a pump supported at the lower end of said column and adapted to discharge thereinto; a prime mover mounted at the surface; drive means extending from said prime mover to said pump for imparting pumping motion to the latter; an inlet chamber enclosing the inlet of said pump, said chamber having inwardly opening check valve means adapted to permit flow of well liquid from the well "into said chamber but preventing outward flow from the chamber to the well; and a submersible motor-pump unit suspended below said chamber, said unit comprising a submersible electric motor and a pump driventhereby, said last-named pump discharging into said inlet chamber and through said first-named pump into said discharge column, and the check valve means said last-named pump during operation of said first-named pump.

5. Deep well pumping apparatus as set forth in claim 3, in which said check valve means comprises a plurality of check valves movable between a first position wherein they seal-said chamber from direct communication with the well during operation of said last-named pump, and a second position wherein they substantially close said chamber from communication with said secondnamed' pump, thereby preventing entrance of solids from said chamber downwardly into said second-named pump during operation of said first-named pump.

ALADAR HOLLANDER.

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