US2808782A - Corrosion and abrasion resistant sump pump for slurries - Google Patents

Description

1 J. w. THOMPSON ETAL ,7

CORROSION AND ABRASION RESISTANT SUMP PUMP FOR SLURRIES Filed Aug. 31, 1953 2 Sheets-Sheet 1 Snnentors; JOHN- W.- THOMPSON,-

ROBERT A. WILSON, ROBERT B. HOLLAND,

Oct. 8, 1957 J. w. THOMPSON EFAL 2,808,782

CORROSION AND ABRASION RESISTANT SUMP PUMP FOR SLURRIES Filed Aug. 51, 1953 2 Sheets-Sheet 2 Z'mveutorg; JOHN W. THOMPSON, ROBERT A. WILSON, ROBERT B. HOLLAND,

nited States PatentOf CORROSION A ND ABRASION RESISTANTSUMP PUMP FOR SLURRIES John W. Thompson, Robert A. Wilson, and Robert B. Holland, Salt Lake City, Utah, assignors to The Galigher Company, Salt Lake City, Utah, acorporatlou of Utah Application August 31, 1953, Serial No. 377,506

2 Claims. (Cl. 103-87) This invention relates to that class of pumps commonly referred to as sump pumps, and is concerned particularly with sump pumps constructed to handle corrosive and abrasive liquids and slurries.

Practically all sump pumps commercially available are constructed in a manner making extremely difiicult, if not entirely impossible, any effective lining of the working parts with corrosion and abrasion resistant material, such as rubber. Furthermore, such pumps merely .produce a sucking action in the sump, which is ineffective to maintain the material to be pumped in a state of agitation sufiicient to keep solids in suspension during the pumping operation.

Thus, heretofore, there has been no sump pump capable of satisfactory general industrial use in connection with the pumping of corrosive or abrasive liquids, particularly semi-liquid slurries.

This invention has, then, as one of its principal objects, the provision of a sump pump which may be economically and effectively lined with rubber or other abrasion-resistant material, without interfering with pump action, and, as another important object, the provision of a sump pump which will accomplish a continuous and effective agitation of the material within the sump at the same time that it carries out its primary pumping function.

Another significant object is to eliminate dead areas within the impeller casing of a sump pump, so that there can be no collection of abrasive materials, to the detriment of the impeller from a wear standpoint.

Furthermore, it is an object to accomplish the above without limiting the extent to which any sump may be drained of material contained thereby, and, intact, with the possibility of removing liquid to even a lower level than is customary, without risk of air-lock.

Another important feature in the accomplishment of the above objects is the fact that the impeller shaft depends, free and clear of other structure, from a bearing suspension in supporting structure adapted to be positioned above the level of liquidin the sump, and that such shaft enters the impeller, casing through and intermediate of an upper opening therein which is sufficiently large .to serve as a suction inlet for the pump. Thus, there is sufficient space between the impeller casing and the impeller shaft to permit the, application of an adequate covering of abrasive-resistant material tothe otherwise exposed metal parts normally submerged in the liquid to be pumped.

Lining of the pump parts with an abrasive-resistant covering is made easier, moreover, by the fact that, in preferred constructions, the interior walls of the impeller casing are concentric with the impeller.

.Another highly important feature resides in the provision of corresponding suction inlet openings in both the upper and lower wallsofthe impeller casing, whereby eifective suction and inflow of material is accomplished at both the top and thebottomsof .thezimpeller casing,

2,808,782 Patented Oct. 8, 1957 which, in conjunction with the impeller mounting, is effective to produce the desired agitating action in the body of material to be pumped.

In order to provide against air lock as the level of liquid in the sump reaches the impeller casing, the impeller is divided into an upper and a lower part by an imperforate, horizontal septum. Thus, there is provided, in effect, both upper and lower pumping mechanisms, which are correlated, respectively, with the upper and lower suction inlet openings. When the liquid in the sump drops below the upper inlet opening, the lower pumping mechanism continues to withdraw the liquid from the sump until the level of liquid reaches the level of the lower intake opening.

Because of the free suspension of the elongate impeller shaft, without bearing or other support along its length, the impeller shaft rotates in contact with the liquid to be pumped, thereby imparting a swirling motion to the liquid in the sump, which adds to the agitation effect of the double inlet arrangement of the impeller casing. The result is a continuous vigorous agitation of the material in the sump, exteriorly of the impeller casing, which agitation is elfective to maintain solids in suspension in those instances where a metallurgical slurry or the like is the material to be pumped.

This action is further enhanced by the fact that, suspended as it is from an upper support, without bearings at its lower end, the elongate impeller shaft executes a limited sideward whipping motion as it gets up to speed, dynamic balance being achieved when operating speeds are reached.

By supporting the pump casing from the impeller shaft supporting structure by means of a plurality of mutually spaced, depending legs positioned circumferentially of the impeller casing, one or more of such legs may be a pipe communicating with the interior of the impeller casing and serving as a discharge conduit for the pump.

Preferred details of construction and further objects and features of the invention will be dealt with in the following description of the preferred specific embodiment illustrated in the accompanying drawings.

In the drawings:

Fig. 1 represents a side elevation, partly in vertical section taken along the line 1-1 of Fig. 3;

Fig. 2, a top plan partly in horizontal section taken along the line 2-2 of Fig. 1;

Fig. 3, a horizontal section taken along the line 3-3 of Fig. '1;

Fig. 4, a similar section taken along the line 4-4 of Fig. 1;

Fig. 5, a view in perspective of the pump of Fig. l, drawnto a reduced scale and partly diagrammatic in character, illustrating a typical flow pattern of liquid in the sump during operation of the pump;

Fig. 6, a perspective detail view, looking from the bottom, of the form of impeller illustrated in Figs. 1 and 6; and

Fig. 7, a similar view of a somewhat different form of impeller.

Referring-to the drawings:

,In the particular embodiment illustrated, the pumpis arrangedforeither direct support on the bottom of the sump, or for suspension from a sump cover. For the latter purpose, a horizontal supporting plate 10 is provided, with openings 11 for use in bolting or otherwise securing the pump .to the sump cover.

The plate 10 serves as a suspension mounting for an elongate impeller shaft '12, which depends vertically therefrom for rotation free and clear of other structure. A bearing 13 rigidly secured to the-plate 10, as by means of bolts 14, journals the shaft 12. for rotation, and provides an intermediate support therefor in its extension from attachment, at 15, Fig. l, to the drive shaft of the customary electric motor 16. Between the motors 16 and the supporting plate 10, the shaft 12 is protected by an elongate housing17 anchored to the plate by means of a base plate 17a.

At the lower end of the impeller shaft 12 is rigidly affixed at horizontally disposed, disk impeller 18. An impeller casing 19 surrounds such impeller, and is mounted in fixed relation thereto by means of a plurality of, in this instance three, legs 20, 21, and 22, see especially Fig. 3, which depend from fixed securement, as by means of welding, to the underside of supporting plate 10.

While any or all of these legs may communicate with the interior of impeller casing 19, and thereby serve as pressure discharge conduits for the pump, in the present instance only the leg 20 is here shown as so doing. For this purpose, it possesses a somewhat larger diameter than the legs 21 and 22, and extends through and upwardly of the plate 10 to a termination 20a adapted to receive such additional discharge piping as may be required by any given installation.

The impeller casing 19 is dimensioned internally to provide ample leeway for the rubber or other corrosion and abrasion-resistant covering indicated in the drawing as being applied to all submerged metal surfaces which are normally exposed to the material being pumped, and is provided with both an upper suction inlet opening 25 and a lower suction inlet opening 26, the two openings being preferably concentric and of corresponding size. As illustrated, such openings possess diameters considerably in excess of the diameter of the impeller shaft 12, so that such impeller shaft is amply spaced from the defining margins of the upper recess 25, to afford effective entry of the to-be-pumped material to the interior of the impeller casing and to provide leeway for limited whipping action of such shaft as it comes up to or drops down from operating speed following the turning on or turning off of the pump.

As will be seen in Fig. 4, the interior ot fhe pump casing 19 is preferably circular and concentric with the circular impeller 18 and impeller shaft 12. This makes for economy and convenience in the lining of the casing with rubber, and contributes to the achievement of dynamic balance by the impeller in its rotation within the casing in those instances, such as that illustrated, where symmetrical discharge ports are not provided.

It will be noted that, in the operation of the pump, see Fig. 5, material from the sump will be drawn into the pump simultaneously from both above and below the impeller casing; furthermore, that the freely suspended impeller shaft 12 is open to and in contact with, along its entire length, the material to be pumped from the sump. This promotes a highly advantageous agitation and circulation of the material to be pumped, which results in solid particles being maintained in liquid suspension during operation of the pump, and, consequently, a minimum of sands collected on the bottom of the sump.

As indicated in Fig. 5, and particularly by the arrows appended thereto, a definite swirling of the liquid to be pumped is produced both above and below the impeller casing by reason of the upper and lower suction inlet openings thereof. Furthermore, a vertical motion is imparted to the body of liquid surrounding the impeller shaft, whereby effective folding over of the slime-carrying or other semi-liquid material to be pumped is effected, together with a feeding of such material into the upper discharge opening longitudinally along the impeller shaft.

It should be particularly noted that, constructed as it is, there are no dead areas within the impeller casing, as are usual with conventional sump pumps, and that the double suction feature provides for an efiective, dynamic sweeping of all parts of the impeller casing by flowing liquid during operation. 3

It is a feature of the invention that the impeller be formed with an imperforate horizontal septum or dividing wall 18a intermediate the vertical extension of the several pump vanes, 18b, so as to, in effect, provide upper and lower pumping portions, both being provided with corresponding vanes 18b. Thus, when the level of liquid in the sump reaches the upper suction inlet 25, the pump will continue to function, without air lock, by reason of the continued submergence of the lower portion of the impeller. In this manner, the desirable agitating feature of the pump is had without sacrifice of pumping effectivcness down to the level of the lower suction intake opening 26, or of any extension thereof which may be provided.

Suitable screens or grids may be provided about the suction inlet openings, for example, as illustrated at 27 and 28, respectively, Fig. 1;

The vanes of the impeller may be of various formations. Thus, instead of being rectilinear and radial, as in the impeller 18, see especially Fig. 6, they may be of the arcuate formation and placed as in the impeller 30 of Fig. 7, where 30a indicates the imperforate septum and 30b indicates the various vanes.

Whereas, this invention is here illustrated with respect to a particular preferred construction, it should be understood that various changes may be made therein without departing from the scope of the claims which here follow.

We claim:

1. A corrosion and abrasion resistant sump pump, comprising a horizontally extending support; an elongate impeller shaft; bearing means mounting an upper portion of said shaft in the support, so that the lower por tion thereof depends vertically from said support free and clear of other structure, said lower portion being rubber covered; a rubber covered, horizontally disposed, circular impeller secured to the lower end of said shaft; a rubber lined casing surrounding said impeller and defining a corrosion and abrasion resistant impeller chamber of right cylindrical formation concentric with and of effectively greater diameter than the impeller; mutually spaced legs depending from fixed securement to said support and secured at their lower ends to said impeller casing for supporting the latter in fixed concentric relationship with said impeller, one of said legs constituting a discharge pipe leading directly vertically from communication with the interior of said casing at the outer periphery thereof and extending through said support to a discharge termination above the support adapted for connection to a discharge line; said casing having a pair of inlet openings formed in mutually opposing relationship centrally of the upper and lower casing walls, respectively, above and below said impeller, said impeller shaft passing through and being spaced apart from the defining margins of the upper of said inlet openings and the impeller being wholly contained within and spaced apart from said casing so that impeller and impeller shaft are free to whip as the pump commences operation; and means in engagement with said impeller shaft above said support for rotating said impeller shaft.

2. The corrosion and abrasion resistant sump pump of claim 1, wherein protective grids are secured to the impeller casing externally thereof and in surrounding relationship to the upper and lower inlet openings thereto, respectively, the upper grid surrounding the impeller shaft in spaced relationship therewith.

References Cited in the file of this patent UNITED STATES PATENTS 1,381,673 Sherwood June 14, 1921 2,143,032 Ruthman Ian. 10, 1939 2,179,730 Ruthman Nov. 14, 1939 2,207,183 Thrush July 9, 1940 2,207,208 Thrush July 9, 1940 (Other references on following page) 5 UNITED STATES PATENTS Thrush Oct. 7, 1941 Duden Apr. 8, 1942 Nagle Nov. 3, 1942 Lamphere Feb. 27, 1951 Ha entjens Jan. 13, 1953 6 Wahle Nov. 17, 1953 Kreitchman Mar. 9, 1954 Staaf Apr. 19, 1955 FOREIGN PATENTS Great Britain Dec. 18, 1919

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