US2219098A - Centrifugal pump - Google Patents

Description

Filed Feb. 4, 19:57 4 shets-snet 1 OsGQRH-DORE INVENTOR A TTORNEY Oct. 22. I940. Q 'H,. DQRER 2,219,098

CENTRIFUGAL PUMP Filed Feb. 4, 1957 4 Sheets-Sheet 2 65 ca R. H ORER. mh mon ATTORNEY 0a. 22, .940. I Q HDokER 2,219,098

CENTRIFUGAL PUMP Filed Feb. 4, 1937 4 Sheets-Sheet 5 55 INVENTOR ATTORNEY Oct. 22, 1940.

o, H. DORER CENTRIFUGAL PUMP Filed Feb. '4, 1957 v 4 Sheets-Shae? 4 Qscmt. H. DORER,

Patented Oct. 22, 1940 UNITED STATES PATENT OFFICE 2,219,098 can'rmrucn. PUMP Application February 4, 1937, Serial No. 124,073

11- Claims.

This inventionrelates to multi-stage high pressure high temperature centrifugal pumps, and an object of the invention is to provide a pump of this type having an inner horizontally split casing and an outer open ended casing designed so that the pump casing and its discharge and sue-- tion heads may be economically and practically forged from steel billets; one which encompasses hydraulic balance and in which all leakage joints are subjected to a minimum number of stage pressures, thereby providing a strong durable multi-stage pump for handling liquids at high temperatures and pressures, which can be economically manufactured, will eliminate leakage and will permit ready access to the interior mechanism of the pump.

The pump of the present invention embodies many novel features of construction, such as a novel manner of connecting the inlet and outlet 29 nozzles of the pump to the casing thereof which simplifies the forging action of the casing; the novel suction head structure which facilitates and simplifies the assembly and manufacture of .the pump; the manner of constructing and assembling in the pump structure of the impeller units and of arrangement to provide hydraulic balance of the pump; together with other novel features of construction which will be hereinafter brought out, all of which combine to provide a practical efficient multi-stage centrifugal pump for handling liquids at high temperatures and high pressures.

With these and other objects in view, as may appear from the accompanying specification, the 35 invention consists of various features of construction and combination of parts, which will be first described in connection with the accompanying drawings, showing a centrifugal pump of the preferred form embodying the invention, and the 40 features forming the invention will be specifically pointed out in the claims.

Inthe drawings:

Figure 1 is a side, elevation of the improved P p.

45 Figure 2 is a longitudinal section through the i ump.

Figure 3 is a cross section through the pump taken on the line 3-3 but having the impellers removed.

60 Figure 4 is a cross section through the suction I '56 Figure 2.

Figure 6 is a vertical section through the suction head of the pump taken on the line 66 of Figure 5.

Figure 6A is a detail section taken approximately on the line 6-6 of Figure 1 and illustrat ing the manner of connecting the inlet and discharge nozzles to the pump casing.

Figure 7 is a section taken on the line I'! of Figure 6A but showing the nozzle in its final posit on.

Figure 8 is a plane view of a; ring employed in attaching the nozzles to the casing.

Figure 9 is a detail section through an impeller unit.

Figure 10 is a. diagrammatic view illustrating the sequence of the impellers, or, illustrating the manner and direction in which the fluid pumped flows through the pump so that the leakage joints of the pump will be free from the maximum discharge pressure of the pump.

Referring more particularly to the drawings, the improved multi-stage centrifugal pump'comprises an outer casing l which in manufacture is preferably made or forged from a steel billet so as to provide maximum strength, and this outer casing i has an inner casing 2 therein in which is located the various impeller units 3 and the pasit sages and volutes as indicated at 4 employed in the pumping of the liquid to be pumped.

The outer casing l. is preferably constructed in the form of an open-ended cylinder and the end of the outer casing at the discharge and of the pump or the end remote from the suction inlet of the pump is closed by a forged steel head 5 which is securely connected to the casing l by 36 suitable bolts 8. A sealing joint i of approved type is provided between the head 5 and the end of the casing i. The suction end of the casing I has a suction head 8 attached thereto and this suction head 8 is of a novel construction so that 40 it may be practically and economically forged, securely attached to the casing I and still have the necessary passage for the inlet of fluid into t e pump- The suction head 8 comprises the flat disc-like body 9 having an eccentric annulus l0 formed thereon and projecting late'rallytherefrom towards the casing I. The annulus Ill has itsthickest portion located preferably atthe top of the pump or at any suitable position depending upon the point from which the liquid is delivered to the pump or the location of the suction or inlet passage connection. The thick portion of the annulus ill is provided with a cut-out portion II which receives therein the inlet or suction nozzle I2 of the pump. As clearly shown in Figures 2 to inclusive of the drawings, the suction nozzle I2 does not extend inwardly to the innermost disc of the cut-out portion II, and this portion communicates through its end and the transversely extending portion I4 thereof with the annular suction chamber in the suction head 8. The annular suction. passage or chamber I5 opens laterally into the suction eye of the first stage impeller I6 of the series of impeller units 3, as clearly shown in Figure 2 of the drawings.

A ring I! ismounted in the eccentric annulus I0 of the suction head 8 and this ring is provided with a plurality of radial passages I8 therein, which may be milled or otherwise suitably cut in the ring, forming alternate radial passages I8 and lugs I9. The lugs I9 engage against the end of the outer casing I and against the inner side of the disc 9 of the suction head 8, and they receive therethrough the body bolts which serve to securely connect the suction head 8 and ring l9 to the outer casing I of the pump. The radial passages I8 establish communication between the outer eccentric inlet passage or portion 2| of the inlet passage I5 and the central or laterally open portion 22 of the suction passage, so that the liquid entering the pump through the suction inlet nozzle I2 passes around through the eccentric passage 2|, the lateral passages I8, the central portion 22 into the suction eye of the first stage impeller I6. By particular reference to Figure 5 of the drawings it will be noted that the eccentric inlet passage 2| gradually decreases in width as it extends away from the inlet chambet I I, thus causing a reduced area for the inlet flow of the liquid and maintaining substantially the same pressure of the incoming fluid at all points about the circle of its inlet.

The inner casing 2 is horizontally split as clearly shown in Figure 3 of the drawings so as to permit ready access to the interior of the casing and to the impeller units therein. The flow passages indicated generically at 4 in the inner casing 2 are so constructed and arranged that the line of flow of the liquid pumped through the pump will be in the manner shown in Figure 10 of the drawings. That is, from the face or suction impeller IS, the fluid flows the full length of the inner casing through a suitable passage 25 in the inner casing to the first stage of the double impeller unit 26 located at the opposite end of the pump. From the first stage of the impeller unit 26 the liquid pumped flows through a suitable passage into the suction of the second stage of the impeller unit 26. The second stage of the impeller unit 26 discharges the pumped liquid into the channel or passage 21 which extends along within the inner casing 2 to the double impeller unit 28' which is next to the single stage suction impeller unit I6. From the first stage of the impeller unit 28 the liquid is discharged into the second stage thereof and from this second stage into the first or outermost stage of the impeller unit 29. The liquid passes through the first and second stages of the impeller unit 29 and is discharged from the final stage thereof into the first stage of the final impeller unit 39 which'is located near the transverse center of the pump with the final discharge from the impeller unit 30 into the space 3| between the inner and outer casings I and2 and finally out through the substantially centrally located discharge nozzle 32. The passages between the first and second stages of the impeller units, all of which are substantially alike and one of which is indicated at 33, have openings therein opening out through the inner casing 2 as shown at 34 for the purpose of facilitating the core operations of casting the inner casing. The openings 34 are closed'by suitable closure plates 35. As shown in Figure 3 of the drawings, the inner casing 2 may have spaced projections 36 thereon which engage the inner surface of the outer casing I to facilitate in the supporting of the inner casing'within the outer casing.

The inner casing 2 has a cylindrical extension or sleeve 31 formed on its end opposite to its suction or inlet end, and this sleeve 36 extends into a suitable opening or counterbore in the head 5, so as to provide a 'slidable connection between the inner and outer casings. The joint between the sleeve 31 and the head 5 is packed by suitable packing 38. The end of the inner casing at the suction end thereof has a flat-faced surface 39 thereon which faces a corresponding fiatfaced surface 40 formed on the outer casing l. A sealing ring 4| which is preferably formed of relatively soft metal, such assoft iron, has its edges embedded respectively in the .end of the outer casing I on which the face 40 is formed and in the end of the inner casing 2 on which the face 39 is formed.

The discharge pressure in the space 3| between the inner and outer casings acts on the inner casing and urges it towards the suction end of the pump, maintaining the faces 39 and 40 in contact and also maintaining the sealing ring H in secure sealing condition so as to prevent the leakage of fluid pumped out of the pump easing into the suction passages therein as well as to prevent leakage of the fluid pumped to the atmosphere outside of the pump.

The impeller units 26, 29, 29 and 30 which aredouble units, are cast in one piece, as clearly shown in Figure 9 of the drawings, and the first and second stages of each of these units are arranged in back to back relation. The casting of the impeller units in one piece provides for strong durable impellers which may be manufactured at a minimum cost, and assembled in the pump structure at a minimum cost.

The impeller units are mounted upon the central operating shaft 42 and this shaft is of novel construction as will be noted by reference to Figure 2 of the drawings. The impeller units are mounted thereon in spaced relation as is necessary and advisable in a balanced multi-stage pump of this type and the shaft 42 is provided with cut-out portions indicated at 43 which form part of the fluid passages of the pump and open into the suction eyes of the impeller units. Also it will be noted that the portions of the shaft, indicated at 44 on which the impeller units are mounted, practically increase in diameter from the suction end of the pump to its opposite end and correspondingly the shaft receiving bores of the impeller units also increase in diameter. The

impeller receiving portions 44 of the shaft 42 have difflcult to maintain tight joints between the nozzles and the casing if the nozzles are constructed specially and attached to the casings.

In the present invention, however, a novel construction and method of attaching the, nozzles is provided which will permit the independent construction of the nozzles and their firm and secure attachment to the casings after the casings have been completed.

The nozzles, regardless of the fact that the suction or inlet nozzle I2 is attached to the inlet head 8 while the discharge nozzle 32 is attached to the casing l are both attached in the same manner,

and only one of them will be described. For inv stance, in attaching the discharge nozzle 32to the outer casing I, the outer casing is drilled to form an opening 50 therethrough which is of substantially the same diameter as the outer diameter of the nozzle. The opening or hole 50 is counterbored as shown at 5|, and the nozzle 32 is then inserted through the opening with itsinner end projecting past the inner wall of the shell I and into the shell as shown in Figure 6A. However, before inserting the nozzle through the opening 50, the inner end of the nozzle is cut away as shown at 52 and channeled at the inner end of the cut-away portion 52 as shown at 53. A split ring 54 which is preferably formed in two sections is then mounted about the inner end of the nozzle with its flange 55 engaging in the channel 53. The nozzle 32 is then pulled back into the opening with the split ring 54 engaging in the counterborek This construction relieves the weld of pressure strains and permits the weld to act only as a sealing means. After the nozzle has been placed in its proper position, the ring 54 is welded to the inner side of the casing l as indicated at 5B, and the nozzle itself is welded to the outer side of the casing as indicated at 51.

The inlet nozzle 12 is attached to the suction head 8 in exactly the same manner.

It will be understood that the invention is not to be limited to thespecific construction or arrangement of parts shown but that they may be widely modified within the invention defined by the claims.

What is claimed is:

1. In a centrifugal pump, a horizontally split inner casing, an outer casing having both ends open, closure heads for said outer casing at its ends, the closure head at the suction end of the pump having an inlet nozzle thereon and provided with an eccentric inlet passage opening laterally into the inlet of the inner casing, and circumferentialiy spaced vanes in said inlet passage and abutting the end of the outer casing.

2. In a centrifugal-pump, an inner casing, an

outer casing enclosing said inner casing, a suction head for the pumpforming a closure for the suction end of the outer casing, saidsu'ction .head having an eccentric annulus extending over head having an eccentric. annulus thereon, circumferentially spaced body bolt receiving vanes in said eccentric annulus, and bolts extending through said vanes and connecting said head and I outer casing.

4. In a centrifugal pump, an inner casing, an

outer casing enclosing said inner casing, a suction head for the pump forming a closure for the in said eccentric annulus, and bolts extending tion passage therein eccentric to the axis of the Pump.

5. In a centrifugal pump, an inner casing, an outer casing enclosing said inner casing, a suction head for the pump forming a closure for the suction end of the outer casing, 'said suction head having a suction passage therein eccentric to the suction'inlet of the inner casing and opening laterally into the suction of the inner casing, an inlet nozzle on said suction head and opening to said eccentric suction passage, a ring in said eccentric suction passage and having circumferentially spaced body bolt receiving vanes therein, and bolts extending through said vanes for connecting said suction head and outer cas ing.

6. In a centrifugal pump; a horizontally split inner casing, an outer casing having both ends open, closure heads for said outer casing at its ends, the closure head at the suction end of the pump having an inlet nozzle thereon and provided with an eccentric inlet passage opening laterally to theinlet of the inner: casing, and a connecting ring connecting said outer casing and said closure head and eccentrically mounted in said inlet passage.

7. In a centrifugal pump, a horizontallysplit inner casing, an outer casing having both ends open, closure-heads for said outer casing at its ends, the closure head at the suction end of the pump having an inlet nozzle thereon and provided with an eccentric inlet passage opening laterally to the inlet of the inner casing, and a connecting ring connecting said outer casing and said closure head and eccentrically mounted in said inlet passage, said inlet passage having-its greatest width at said inlet nozzle and gradually decreasing in area in both dire'ctions'from the inlet nozzle.

8. In a centrifugal pump, a casing, a suction head thereon and comprising a flat disk-like body having an annulus formed thereon and projecting laterally therefrom, a ring mounted in said annulus and co-operating therewith to form an eccentric suction passage for the pump.

9. In a centrifugal pump, a casing, a suction head thereon and comprising a fiat disk-like body having an annulus formed thereon and projecting laterally therefrom, a ring mounted in said annulus and co-operating therewith to form an eccentric suction passage for the pump, said suction head having an inlet nozzle thereon, said inlet passage having its greatest width at said inlet nozzle and gradually decreasing inarea in both directions from the inlet nozzle. J

10. In a centrifugal pump, an inner casing, an outer casing having its suction end open, a closure head for said open suction end having an. inlet nozzle thereon and provided with a chamber.

opening into the inner casing, an impeller in said inner casing, and means in said chamber restrict...

' through said vanes and connecting said head and outer casing, said suction head having a suc..

ing the chamber to provide an eccentric inlet passage opening laterally to said impeller, said eccentric passage having its greatest area at said inlet nozzle and gradually decreasing in area in both directions from the inlet nozzle.

11. In a centrifugal pump, an inner casing, an

outer casing enclosing said inner casing and spaced circumferentially therefrom to provide a pressure chamber within the outer casing and 10 about the inner casing, a sleeve formed on one

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