US3520643A - Sewage pump or the like - Google Patents

Description

JuHy Mw E97@ o. A. RUSSE ETAL SEWAGE PUMP OR THE LIKE Filed om, 22 196e FME. fi

www Am United States Patent O U.S. Cl. 417--434 5 Claims ABSTRACT 0F THE DISCLOSURE A reciprocative pump adapted to handle sewage or other particle laden liquids is provided with novel inlet and outlet check valves adapted to be urged continuously of precipitated solid particles which otherwise could plug the valves. Contrary to the customary practice of pumping the liquid upwardly from the inlet valve to the outlet valve, the liquid preferably flows through the pump in a downward direction to minimize the accumulation of solid particles between the two valves. A novel trap arrangement also may be provided between the outlet valve and the pumping chamber to collect heavy sediment and to allow it to be discharged without interrupting operation of the pump.

The present invention relates to the elimination of check valve malfunctioning in reciprocative pumps adapted to handle sewage or other liquids laden with suspended solid particles.

To pump sewage or other particle laden liquids, it is well known to employ a reciprocative pump of the general previously known type shown in FIG. 1 of the accompanying drawings. In such a pump, respective substantially identical inlet and outlet check valves 11 and 12 are attached to the pump body member 13 and communicate with a pumping chamber 14 which is alternately increased and decreased in volume by the movement of resilient diaphragm 15 operated by reciprocating piston 16 in cylinder bore 17. The check valves, in turn, customarily comprise check balls 18 which rest by gravity on their respective valve seats 19. Typically, the inlet check valve is located directly below the pumping chamber, as illustrated, whereby a pulsating ow of liquid takes place in an upward direction through the pump in response to reciprocation of diaphragm 15.

Due to the location of the inlet check valve below the pumping chamber, it will be seen that a considerable volume of liquid is contained within the pump above that valve. Therefore, solid particles which precipitate out of the liquid within the pumping chamber tend to settle downwardly and to collect in the annular pocket 21 around the seat of the inlet check valve, out of the direct path of flow of the liquid being pumped. Since the crosssectional area of the pumping chamber is greater than that of the inlet check valve and the conduit leading thereto, the intermittent upward liquid velocity in the pumping chamber is less than through the valve; thereby further encouraging the above-described precipitation of solid particles within the pumping chamber. As this sediment continues to deposit around the inlet valve, it eventually accumulates sufficiently to prevent that valve ball from effectively closing its valve seat, whereupon the pump ceases to operate efliciently, if at all. A similar phenomenon also occurs about the outlet valve, particularly if the discharge pipe leading from that valve extends upwardly by any appreciable distance. Consequently, it is often necessary to stop the pump and clean the valves by removing cover plugs 22 and washing out accumulated sediment deposits with a high pressure Water stream or other means.

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3,520,643 Patented July 14, 1970 ice Needless to say, this operation is both inconvenient and uneconomical, as well as being very unhygienic in the case of pumps handling raw sewage, contaminated industrial sludge or other noxious fluids.

In accordance with the present invention, the abovedescribed problems of check valve malfunctioning are substantially eliminated by employing check valves designed in a manner such that the valve balls or analogous valve members are positioned above their respective seats within relatively confined internal valve chambers from which the liquid being pumped discharges downwardly around the valve seats. Also, without interfering with the substitution of the improved check valve units for previously known check valves in conventional pump units, the invention contemplates reversing the positions of the two valves so that the liquid moves downwardly through the pump and therefore does not encourage sedimentation from occurring in the pumping chamber. Accordingly, the invention substantially eliminates this plugging problem by decreasing the volume of liquid from which solids can precipitate about the valve seats, reducing the tendency of such precipitation to occur in the pumping chamber, and providing for continuous purging of the valve seat regions by heavy discharge through those valves. Furthermore, a trap is incorporated in the improved outlet check valve structure to collect particles too heavy to be carried in suspension through that valve and to allow such particles to be discharged while the pump remains in operation.

Various other advantages and features of the invention will be apparent from the following detailed description of an illustrative embodiment thereof, reference being made to the accompanying drawings in which like reference numerals refer to like elements.

In the drawings:

FIG. 1 is a cross-sectional elevational view of the illustrative previously known pump referred to in the foregoing description of the prior art;

FIG. 2 is a cross-sectional elevational view of a pump employing the same basic pump body depicted in FIG. 1 but provided with check valve means constructed and installed in accordance with a preferred embodiment of the present invention; and

FIG. 3 is a cross-sectional elevational view of an alternate embodiment of the inlet valve structure depicted in FIG. 2, incorporating a spring loaded valve ball.

As will be apparent by comparison wtih FIG. 1, the illustrative preferred embodiment of the invention depicted in FIG. 2 embodies the same pump body member described above, with corresponding parts being identilied by the same reference numerals. Replacing the prior art check valves, however, are a pair of substantially identical inlet and outlet valve units 25 and 26 in accordance with the present invention. Each of these units comprises a generally tubular vertically disposed housing 27 provided with a lower ilange 28 surrounding the lower opening to the internal valve chamber 29. The upper seating portion 30 of an L-shaped valve seat tube 31 is supported centrally of the internal valve chamber by the horizontal portion of the tube, which extends through the side of the valve unit and terminates in a side ilange 32. As illustrated, the valve seat tube preferably is formed integrally with the valve housing by known molding or casting techniques. A valve ball 33 is located atop the upper seating portion of the L-shaped tube and is guided laterally by iingers 34 projecting downwardly from cover plug 35 threaded into the top of the valve housing. Thus, the ball remains directly above its seat but rises to allow liquid to pass upwardly out of tube 31. As previously mentioned, it will be apparent that this structure therefore minimizes the amount of liquid present directly above the check ball and also provides for continuous purging of the valve seat by the liquid flowing downwardly around the seat tube toward the discharge opening in ilange 28.

The inlet check valve unit is mounted by means of its lower ange 28 to the upper ange 36 of the pump unit, rather than to the lower pump unit ange as in the prior art structure depicted in FIG. 1; thereby admitting liquid to the pump chamber in a downward direction whenever the volume of that chamber is increased by movement of diaphragm 1S. The lower ange 37 of the pump unit is bolted to an elbow tramp member 38, which, in turn, is provided with a lateral ange 39 connected to the side flange 32 of the outlet check valve. Consequently, each time the volume of the pumping chamber is decreased by diaphragm 15, liquid is forced downwardly from that chamber through the U-shaped channel 40 defined by the elbow tube and the L-shaped valve seat tube of the outlet valve unit and is discharged through the lower outlet opening of that valve unit. Since the U-shaped channel is below both the pumping chamber and the outlet valve seat, any particles too heavy to be carried upwardly past the outlet check ball will collect in that channel. Therefore, elbow trap member 38 is provided with a vertical trap member 41 located directly below the pumping chamber to define a trap chamber 42 in which such heavy particles are collected. Periodically, this chamber can be emptied by momentarily opening clapper valve 43, without requiring the operation of the pump to be interrupted. Obviously, the depicted clapper valve is only illustrative and could be replaced by an analogous valve structure, such as a multi-cell rotary valve, housed entirely within a discharge conduit to prevent exposure of the operator to the material discharged from the trap.

Experimentation with a pump of the type just described showed that it was capable of continuously handling waste water sludge containing from 3 to 15 percent by weight of suspended solid materials, including even irregularly shaped pebbles up to 25 mm. in effective diameter, without significant reduction in a predetermined discharge pressure of pounds per square inch. By comparison, the same type of pump unit provided with conventional check valves in the manner illustrated in FIG. 1, failed completely to handle the same sludge concentration even in the absence of pebbles.

By virtue of the fact that the check valve balls of the subject valve units operate within relatively confined chambers which are not in direct upward communication with the liquid being pumped, it is also possible to urge the valve balls of either or both valve units downwardly against their seats by spring loaded means; which would be entirely impractical in the sedimentary environment above the valve balls of the units depicted in FIG. 1. As illustrated in FIG. 3, such an arrangement can comprise a plunger `44 extending downwardly through a cover disk 45 threaded into the top of housing 27 and urged downwardly by a spring 46 compressed between a flange 47 on plunger 44 and a cap member 48 threaded onto cover disk 4S.

Although the illustrative embodiments of the invention comprise check valves employing valve balls, it should of course be apparent that the invention also encompasses the use of other types of valve elements including conical, hemispherical or flat poppet valves and various types of hinged clapper valve arrangements.

The invention has been described in detail with particular reference to a preferred embodiment thereof, but

it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

We claim:

1. A pump particularly suitable for handling particle laden liquids, said pump comprising:

(a) body means defining an internal pumping chamber;

(b) reciprocative means for periodically increasing and decreasing the volumetric capacity of said pumping chamber, and

(c) a pair of substantially similar check valve units,

each of which includes (l) a generally vertical tubular body member closed at its upper end and defining an internal valve chamber extending downwardly to an outlet opening at the lower end of said body member,

(2) a tubular seating tube member defining an L- shaped inlet passageway extending from an inlet opening laterally of said body member to a generally horizontal valve seat defined by the upper end of said seating tube centrally within said pumping chamber and (3) a valve member located atop said valve seat and movable upwardly from said seat to allow liquid to pass through said unit only in the direction from said inlet opening to said outlet opening,

(d) means for connecting one of said valve units to said body member as an inlet valve with its outlet opening in direct communication wtih said pumping chamber and for connecting to other of said valve units to said body member as an outlet valve with its inlet opening in direct communication with said pumping chamber, whereby liquid pumped through said valve units flows downwardly from the valve seats of both of said valve units.

2. The invention defined by claim 1 in which said inlet and outlet valve units are located respectively above and below said pumping chamber to provide a downward flow of pumped liquid through that chamber.

3. The invention defined by claim 1 in which at least one of said valve units includes a spring biased member urging the valve member thereof downwardly onto its corresponding valve seat.

4. The invention defined by claim 1 in which the means for connecting said outlet valve to said pumping chamber comprises an elbow tube having a top opening joining a bottom opening into said pumping chamber and a lateral opening joining said inlet opening of said outlet valve.

5. The invention defined by claim 4 in which said elbow tube includes a trap chamber extending downwardly therefrom below said pumping chamber and movable closure means providing for removal of collected material from said trap chamber while said pump is in operation.

References Cited UNITED STATES PATENTS ROBERT M. WALKER, Primary Examiner U.S. Cl. X.R. 417-383, 559

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