US2458607A

US2458607A - Self-priming centrifugal pump

Info

Publication number: US2458607A
Application number: US589492A
Authority: US
Inventors: Lauchenauer Hermann
Original assignee: Individual
Current assignee: Individual
Priority date: 1944-06-13
Filing date: 1945-04-21
Publication date: 1949-01-11
Anticipated expiration: 1966-01-11
Also published as: DE870495C; CH240031A

Description

E. 11, 3949.. H. LAUCHENAUER 2,458,607

SELF-PRIMING CENTRIFUGAL PUMP Filed April 21, 1945 2 Sheets-Sheet l /N VENT OR.- HERMA NN PLAUCHENAUER Jan H, 1949. H. LAUCHENAUER SELF-PRIMING CENTRIFUGAL PUMP Filed April 21, 1945' 2 Sheets-Sheet 2 R? R L m A R N N E NEfl v VAHK NMG A /RU 14B EAHVI Patented Jan. 11, 1949 UNITED STATES PATENT OFFICE Application April 21, 1945, Serial No. 589,492 In Switzerland June 13, 1944 was inserted directly in the pressure pipe, and

the ejector directly connected to the latter, making it necessary to have the pressure line extended below the level of the pump, in order to permanently remain filled with water. However, with this arrangement, the ejector was permanently kept running during the operation of "the pump, thus continuously causing eddies to rise in the water circulation inside the pump which was accompanied by a corresponding loss of energy, because an essential part of the.total delivery was traversing said ejector. To overcome this drawback it' was proposed to insert in the pressure pipe below the separator, a second ejector,

connected with the ejector of the suction pipe,

and acting in the delivery direction. This seca 0nd ejector which was traversed by the total delivery, would certainly have compensated the circulation during normal running but resulted again in a loss of energy, owing to its throttling action. Furthermore, there was a tendency toobstruction of the nozzle of the second ejector while delivering liquids carrying large solid bodies,

such as in pumps forstone dredgers. Pumpsof the last mentioned kind had the further drawback, that the stones carried along with the water which according to the delivery of the pump, often reached aweight of several kilograms, were then violently thrown against the walls of the' air separator vessel, resulting in latter.

According to the invention, this drawback is overcome in that the air separator, instead of being inserted directly in the pressure pipe, is arranged in shunt, and the ejector nozzle condamage of the nected to a branch pipe of said pressure pipe.

With this arrangement, only the quantity of liquid which is absolutely required for the selfpriming when starting the pump, is flowing through the suction ejector, therefore during normal operation, the circulation within the pump system, will accordingly be equally reduced, and

' in virtue of the inertia of the delivery flow in the pressure piping, no solid bodies can penetrate 8 Claims. (Cl. 10311 3) the additional ejector and the two latter, a 1ongitudinal and a transversal section view of the into the air separator vessel. By the provision of a grate inthe connection between the air separator and the pressure pipe provided with a stripper device to be externally operated, the security of preventing solid bodies fromentering the air separator vessel, can still further be increased.

An additional suction ejector communicating with the pressure side of the pump should preferably be inserted in the ejector pipe; this additional ejector providing a suction effect on the pressure side of the pump, thereby causing a load reduction of the thrust bearing of the pump.

On the accompanying drawings, the constructional form of the pump, according to the invention, is illustrated, whereby:

Fig. 1 is a schematical longitudinal elevation view of a centrifugal pump group, of which Fig. 2 shows an elevation infront view, an

Fig. 3 a top plan view;

Fig. 4, 5 and 6 are drawn to a larger scale and show: the first, a longitudinal section --view of connection between the air separator vessel and the pressure pipe;

Fig. '7 and 8 show on a still larger scale, a vertical section view of two diiferent embodiments of the connection between the air separator vesseland the pressure pipe.

The pump plant shown in the drawings, intended to be used as a stone dredger pump, comprises the centrifugal pump P directly coupled to the electric motor M. The suction pipe 8, ex-

tending above the pump, is provided on its apex with an air inlet valve V. The liquid flow entering through the suction-pipe S, mingled with stones and mud, is expelled through the pressure pipe D. The air separator vessel L, is arranged in shunt to the pressure pipe D at such a height, I

dotted line, in such a manner, that after a stoppage, the self-priming becomes efl'ective by means of the ejector. The ejector to the nozzle 2 of which water is delivered through a branch pipe I connected with the bottom of the air separator vessel L, which nozzle protrudes into the connecting bend 3 of the suction pipe, when put into operation produces the extraction of air from the suction pipe S, and the suction begins, so

that only a small quantity of water flows through the pump. In front of the nozzle 2, a second and smaller nozzle 4, is inserted in the pipe I, a pipe 5 connecting said second nozzle with the pressure side of the pump at 5. This latter nozzle 4, constitutes an additional suction ejector, owing to the fact, that it produces a decrease of separation of air.

w effect is produced in the direction of the arrow,

pressure on the pressure or back side of the pump rotor, resulting in a reduction of the load of the ball thrust bearing K of the pump.

The air separator vessel L, is connected to the section II of the pressure pipe, by means of a connecting chamber 10, the junction aperture of which is closed in the pipe I I, by longitudinally arranged grate bars l2. In the transversal direction of the chamber i0, is journalled a shaft l3, to which are secured stripper rods I4 located between the grate bars and extending over their whole length, thereby permitting the cleaning of the grate from little stones which have become jammed between the grate bars. On the exterior end of shaft I 3, laterally protruding through a stuffing-box, is secured an operating lever l5, permitting an oscillatory motion of said shaft together with the stripper rods, thereby giving the possibility of always keeping the passages through the grate to the air separator vessel unobstructed.

Owing to this arrangement, all damage to the air separator vessel by stones carried in the flow of water, is completely excluded.

On the suction and pressure side of the pump, are connected clearing pipes 'l and 8, to keep the pump clean of sand and gravel, by means of water delivered under high pressure through the pressure line 9.

Under certain circumstances, it is also desirable to provide means for a reduction of the interior circulation produced in the pump system by the influence of the ejector and to reduce the energy loss.

Two different arrangements to realize this requirement are shown in Figs. 7 and 8.

Where the embodiment according to Fig. 7 is concerned, a connection is formed in a similar manner as above described, between the air separator vessel L, and a lateral connecting chamber which join laterally in a pipe 2|, concentrically surrounding the pressure pipe I I, and the diameters of the two concentric pipes which are placed in such a manner to allow for a small annular space remaining between these pipes which are connected to each other at their ends by flanges. The interior pipe I l is provided on the part of its circumference located near the chamber In by upwardly inclined ports 22 for the At the same time, a suction drawn as a dotted line under the influence of the water flowing in the pressure pipe in the direction of the under arrow, said suction effect being opposed to the suction effect of the pump 2, 4, i. e. to the inner circulation and annuls same to an essential part. With this arrangement the solid bodies are also safely prevented from entering the air separator vessel.

The embodiment shown in Fig. 8 is particularly effective. The pressure pipe II is joining concentrically an outer pipe 3|, connected laterally with the chamber l0, and having a greater diameter than the pressure pipe H, and the top end of the latter is connected with its outwardly curved margin with the outer pipe 3| which latter is extended with the same diameter so as to form the pressure pipe II. In the outwardly curved margin are provided around the circumference bores 32 above which, owning to this arrangement, is created by the traversing pressure water, a Venturi effect in the enlarged part of the pres sure pipe, resulting in a suction effect in the direction of the dotted arrow. When the pump is functioning normally, the inner circulation is consequently annuled to an essential part.

I do not limit my invention to the structure shown and described as modifications, within the scope of the appended claims, may be made without departing from the spirit of my invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A self-priming pump system comprising a centrifugal pump, a suction conduit extending above said pump, an ejector inserted in and having a nozzle terminating and discharging into said suction conduit, a discharge conduit, an air separator disposed separated from said discharge conduit and connected for fluid flow therewith, and a conduit connecting said air separator and said ejector and conducting fluid from said separator into said nozzle.

2. A self-priming pump system comprising a centrifugal pump, a suction conduit extending above said pump, an ejector inserted in and having a nozzle terminating in and discharging into said suction conduit, a discharge conduit, an air separator disposed separately from said discharge conduit, a conduit interconnecting said discharge conduit and said separator, a grate means disposed in said last mentioned conduit and comprising movable grate closing and opening means, and operating means connected with said closing and opening means and extending outside of said last mentioned conduit.

3. A pump system as defined in claim 1, having debris retaining means connected with said discharge conduit and comprising ports extending for fluid flow substantially in the direction of imaginary flow lines extending from said air separator into the direction of the normal flow of the fluid through said discharge conduit.

4. A self-primin pump system comprising a centrifugal pump, a suction conduit extending above said pump, an ejector inserted in and having a nozzle terminating in and discharging into said suction conduit, a discharge conduit, an air separator disposed separately from said discharge conduit, a conduit interconnecting said discharge conduit and said separator, said last mentioned conduit comprising a portion partly surrounding and spaced from said discharge conduit, and said discharge conduit comprising port means extending substantially in the direction of imaginary flow lines extending from said separator into the direction of the normal flow through said discharge conduit.

5. A self-priming pump system comprising a centrifugal pump, a suction conduit extending above said pump, an ejector inserted in and having a nozzle terminating in and dischargin into said suction conduit, a discharge conduit, an air separator disposed separately from said discharge conduit, conduit means interconnecting said discharge conduit and said separator, said discharge conduit extending into said conduit means and terminating therein and having an end portion slightly spaced from the inside of said conduit means, and said conduit means continuing as discharge conduit beyond said end portion.

6. A self-priming pump system comprising a centrifugal pump, a suction conduit extending above said pump, an ejector inserted in and having a nozzle terminating in and discharging into said suction conduit, a discharge conduit, an air separator disposed separately from said discharge conduit, conduit means interconnecting said discharge conduit and said separator, said discharge 5 conduit extending into and being partly surrounded by and spaced from said conduit means and having a flared end portion extending to the inside of said conduit means, said conduit means continuing as discharge conduit beyond said end portion, and said end portion having openings interconnecting said discharge conduit and said conduit means for fluid flow.

7. A pump system as defined in claim 1, having an additional ejector having a nozzle discharging into the conduit interconnecting said air separator and said first ejector, and a conduit connecting said additional ejector and the pressure or back side of the pump.

8. A pump system as defined in claim 1, having cleaning conduits supplied with a high pressure fluid connected with the front and with the back side of the pump,

HERMANN LAUCHENAUER.

REFERENCES CITED The following references are of record in the file of this patent:

Number Number 'UNITED STATES PATENTS