Centrifugal Pump Having Leakage Collection And Draining Means

Abstract

A centrifugal pump in which the hub portion of the casing cover is provided with a liquid leakage collecting channel having a recessed portion communicating through a drainage outlet with a conduit discharging liquid collected in the channnel. Also, the side face of the casing cover external to the pumping chamber slopes downwardly towards its periphery for facilitating collection of liquid at the periphery; and a drainage conduit communicates with such periphery for removing the collected liquid.

Description

The present invention relates to centrifugal pumps and more particularly to the collection and drainage of liquid leakage and other liquid external to the pumping chambers of such pumps.

In conventional vertical centrifugal pumps, liquid leakage from the pumping chamber along the impeller shaft generally has been allowed to collect on the side face of the casing cover external to the pumping chamber where, in combination with cleaning water and other liquid entering the pump housing from outside sources, it remained in a stagnant pool until subsequent dismantling of the pump. This accumulation of the leakage and other liquid in a stagnant pool on the casing cover is highly objectionable and, depending on the nature of the leakage, can result in external corrosion of the pump components and/or present a potential hazard due to its fumes or toxicity. Also, due to this pool, the dismantling of these conventional pumps must proceed with extreme care lest the pool be spilled on adjacent surfaces and/or attending personnel; and the outside liquid component of the pool presents the danger of possible contamination of the liquid being pumped.

An object of the present invention is to provide a new and improved centrifugal pump which is particularly constructed and arranged to prevent the formation of the aforedescribed stagnant pool of liquid.

Another object of the invention is to provide a new and improved centrifugal pump which is particularly constructed and arranged to permit the collection and drainage of leakage and other liquid from the pump.

In accordance with the present invention, a centrifugal pump may comprise a casing containing a pumping chamber and having inlet and discharge ports connected to the pumping chamber, a casing cover mounted on the casing and having a side face bounding one side of the pumping chamber and an opposite side face external to the pumping chamber, the casing cover including a central hub portion projecting from its said opposite side face, a rotatable shaft extending through the hub portion of the casing cover, an impeller in the pumping chamber mounted on the shaft, sealing means in the hub portion around the shaft for restricting leakage from the pumping chamber through said hub portion, the hub portion having a collar therearound and the collar including a collecting channel extending around the shaft, such collecting channel including a portion recessed from another portion thereof, outlet means communicating with the recessed portion of the collecting channel for draining liquid therefrom, said opposite side face of the casing cover sloping downwardly from the hub portion towards its outer periphery to facilitate drainage theretowards and outlet means communicating with the outer periphery of said opposite side face of the casing cover for draining liquid there from.

FIG. 1 is an elevational sectional view of a vertical in-line centrifugal pump embodying the invention taken on Line 1--1 of FIG. 2, looking in the direction of the arrows;

FIG. 2 is a sectional view of the pump shown in FIG. 1 taken on Line 2--2 of FIG. 1, looking in the direction of the arrows; and

FIG. 3 is an enlarged fragmentary elevational sectional view of such pump taken on Line 3--3 of FIG. 2, looking in the direction of the arrows.

Referring more particularly to the drawings wherein similar reference characters designate corresponding parts throughout the several views, the illustrated vertical in-line centrifugal pump comprises a casing 10 containing a pumping chamber 12 and provided with a flat annular plate shroud 14 which is detachably mounted in an annular recess 16 in the casing 10 such that its flat upper surface 18 bounds the lower or forward side of the pumping chamber 12. The casing 10 includes the usual centrifugal pump surface 20 below the plate shroud 14 and has an annular wall 22 peripherally bounding the pumping chamber 12. The casing 10 comprises an inlet 24 communicating with the pumping chamber 12 through the opening 26 in the plate shroud 14 and an outlet 28 connected to the pumping chamber 12 through the annular wall 22, the inlet 24 and outlet 28 being in the conventional manner provided with integral flanges 30, 32, respectively, for connecting the pump in the pipeline through which the liquid is to be pumped.

A casing cover 34, having an annular flange 36 supported on an annular ledge 38 of the casing 10, is detachably clamped to the latter by eccentric washers 40 mounted to the casing 10 by mounting bolts 42 and engaging an annular upright peripheral rim or flange 41 on the casing cover 34. Leakage between the flange 36 and the ledge 38 is the usual manner prevented by a therebetween annular sealing gasket 44. The casing cover 34 includes an annular flat lower surface or side face 46 sloping downwardly towards the outer periphery of the casing cover 34 and bounding the upper or rearward side of the pumping chamber 12; and the casing cover 34 also includes an annular flat upper surface or side face 48 external to the pumping chamber 12. The casing cover 34 includes an integral central hub portion 50 which extends upwardly from its upper side face 48 and contains a vertical bore 52 extending through the casing cover 34.

A vertical, rotatable impeller shaft 54 extends through the bore 52 and at its lower end carries an impeller 56 in the pumping chamber 12. The impeller 56, as illustrated, includes a rear shroud 58, but no front shroud, and has a plurality of vanes 60 and radial blades 60a. Conventional packing or sealing rings 62, intended for preventing liquid leakage from the pumping chamber 12 along the impeller shaft 54, are provided in the bore 52 around the impeller shaft 54. The packing 62 is detachably mounted in operative position by an annular clamping element 64 which contains a bore 66 rotatably receiving the impeller shaft 54 and has a depending portion 68 extending into the bore 52 in engagement with the uppermost of the packing 62. The clamping element 64 is connected by mounting bolts 72 to an annular collar 74 formed integrally around the upper end of the hub portion 50.

At its upper end, the impeller shaft 54 is connected by a coupling 76 to the lower end of a motor shaft 78 which is at its upper end connected to be rotatably driven by the pump motor 90. The coupling 76 may, if desired, include conventional adjusting means operable for vertically moving the impeller shaft 54 to thereby adjust the clearance of the impeller 56.

A housing 80, surrounding the coupling 76 and adjacent portions of the pump, includes an annular flange 82 seating on an annular ledge 84 of the casing 10 to cause the casing 10 to support the housing 80. The housing 80, as shown in FIG. 2, is detachably mounted to the casing 10 by four mounting bolts 86 at equally spaced locations therearound. The housing 80 contains a plurality of large side openings 88 adapted to permit ready access to its interior and at its upper end supports the pump motor 90.

In the illustrated embodiment of the invention, the upper surface of the collar 74 of the casing cover hub portion 50 is provided with a relatively shallow, annular, liquid collecting channel or trough 92 encircling the impeller shaft 52. A minor arcuate portion of this channel 92 is substantially deepened to form a deeper recess or pocket 94 in communication with the remainder of the channel 92 and having its bottom 96 substantially below the bottom 98 of such remainder. A drainage outlet 100 is formed through the outer wall 102 of the channel 92 in communication with the recess 94 immediately above the level of its bottom 96; and a drainage conduit or pipe 104 is connected to the recess 94 at the drainage outlet 100 and projects through an opening 106 in the housing 80 to drain liquid externally of the latter. As illustrated in FIG. 2, the housing 80 is preferably provided with a plurality of such openings 106, adjacent openings 106 being at 90.degree. intervals, to permit adjustment of the angular mounting of the housing 80 on the casing 10.

Also, in the illustrated embodiment of the invention, the upper side face 48 of the casing cover 34 is flat and continuously slopes downwardly as it extends outwardly from the hub portion 50 to the peripheral flange 41. A drainage outlet 108 is formed radially through the peripheral flange 41 to receive liquid on the outer periphery of the side face 48 immediately above the level of the latter; and an aligned drainage outlet 110 is formed through the casing 10. A drainage conduit or pipe 112 is connected to the outlet 110 to receive liquid drained through the communicating outlets 108, 110 and discharges the received liquid externally of the pump.

In the operation of the pump, the impeller 56 is continuously rotatably driven in the pumping chamber 12 to pump liquid from the inlet 24 through the outlet 26. Liquid leakage along the impeller shaft 54 through the packing 62 passes into the channel 92 and thence into the recess 94 from whence it is discharged to a point of disposal external to the pump through the drainage conduit 104. Liquid flowing onto the upper side face 48 of the casing cover 34, whether entering the housing 80 through the side openings 88 or otherwise passing onto the upper side face 48, flows outwardly to the periphery and is discharged therefrom through the drainage openings 108, 110 and the drainage conduit 112. Hence, the formation of the stagnant liquid pools normally present in conventional pumps of this general type is prevented; and the aforedescribed hazards and dangers of such pools are resultantly avoided.

Although only a single embodiment of the invention has been illustrated and hereinbefore specifically described, it will be understood that this illustrated embodiment has been given by way of example only; and the invention is not limited merely to this single embodiment, but rather comprises other embodiments and variations within the scope of the following claims.

Claims

Having thus described my invention, I claim:

1. In a centrifugal pump adapted to be generally vertically mounted, a casing containing a pumping chamber and having inlet and discharge ports connected to said pumping chamber, a casing cover mounted on said casing and having a side face bounding one side of the pumping chamber and an opposite side face external to said pumping chamber, said casing cover including a central hub portion projecting from its said opposite side face, a rotatable shaft extending through said hub portion of said casing cover, an said pumping chamber mounted on said shaft, sealing means in said hub portion around said shaft for restricting leakage from said pumping chamber through said hub portion, said hub portion having a collar therearound and said collar including a collecting channel extending around said shaft, said collecting channel including a portion recessed from another portion thereof, outlet means communicating with said recessed portion of said collecting channel for draining liquid therefrom, said opposite side face of said casing cover sloping downwardly from said hub portion towards its outer periphery to facilitate liquid drainage theretowards, and outlet means communicating with the outer periphery of said opposite side face of said casing cover for draining liquid therefrom.

2. A centrifugal pump according to claim 1, wherein said periphery of said opposite side face of said casing cover is provided with a generally upstanding rim.

3. A centrifugal pump according to claim 1, further comprising a plate detachably mounted to said casing bounding the side of said pumping chamber opposite to said one side thereof.

4. A centrifugal pump according to claim 3, wherein said plate is generally annular and said inlet port communicates with said pumping chamber through the opening in said plate.

5. A centrifugal pump according to claim 1, wherein said side face of said casing cover bounding one side of the pumping chamber slopes downwardly from said hub portion of said casing cover towards its periphery.

6. In a centrifugal pump adapted to be generally vertically mounted, a casing containing a pumping chamber and having inlet and discharge ports connected to said pumping chamber, a casing cover mounted on said casing and having a side face bounding one side of the pumping chamber and an opposite side face external to said pumping chamber, said casing cover being provided with a central hub external to said pumping chamber, a rotatable shaft extending through said central hub, an impeller in said pumping chamber mounted on said shaft, sealing means contained in said central hub around said shaft to restrict fluid flow from said pumping chamber through said central hub, said central hub being provided with a recessed collecting channel for receiving and collecting liquid passing from said pumping chamber through said central hub, and means communicating with said collecting channel for draining liquid therefrom.

7. A centrifugal pump according to claim 6, wherein said collecting channel surrounds said central hub.

8. A centrifugal pump according to claim 6, wherein said collecting channel includes a portion deeper recessed than another portion thereof, said draining means being connected to said deeper recessed portion.

9. In a centrifugal pump adapted to be generally vertically mounted, a casing containing a pumping chamber and having inlet and discharge ports connected to said pumping chamber, a casing cover mounted on said casing and having a side face bounding one side of the pumping chamber and an opposite side face external to said pumping chamber, said casing cover having a central hub portion external to said pumping chamber, a rotatable shaft projecting through said hub portion of said casing cover, an impeller in said pumping chamber mounted on said shaft, sealing means in said hub portion around said shaft for restricting liquid flow from said pumping chamber through said hub portion, said opposite side face of said casing cover sloping downwardly towards its periphery, and drainage means communicating with the periphery of said opposite side face for draining liquid therefrom.

10. A centrifugal pump according to claim 9, further comprising a plate detachably mounted to said casing bounding the side of said pumping chamber opposite to said one side thereof.

11. A centrifugal pump according to claim 9, wherein said plate is generally annular and said inlet port communicates with said pumping chamber through the opening in said plate.

12. A centrifugal pump according to claim 1, wherein said outlet means in communication with said recessed portion of said collecting channel comprises an outlet through a wall of said collecting channel and a drainage conduit connected at said outlet.

13. A centrifugal pump according to claim 6, wherein said liquid draining means comprises an outlet through a wall of said channel and a drainage conduit connected at said outlet.

14. A centrifugal pump according to claim 6, wherein said collecting channel includes a portion deeper recessed than another portion thereof, said liquid drainage means is connected to said collecting channel at said deeper recessed portion thereof, and said liquid draining means comprises an outlet through a wall of said channel and a drainage conduit connected at said outlet.

15. A centrifugal pump according to claim 14, wherein said outlet communicates with said deeper recessed portion adjacent the bottom of said deeper recessed portion.

16. A centrifugal pump according to claim 9, wherein said periphery of said opposite side face of said casing cover is provided with a generally upstanding rim.

17. A centrifugal pump according to claim 16, wherein said drainage means comprises a drainage outlet through said rim.