US3649131A

US3649131A - Self-priming lateral channel centrifugal pump

Info

Publication number: US3649131A
Application number: US51918A
Authority: US
Inventors: Hagemann Walter
Original assignee: Siemen and Hinsch GmbH
Current assignee: Siemen and Hinsch GmbH
Priority date: 1969-07-05
Filing date: 1970-07-02
Publication date: 1972-03-14
Anticipated expiration: 1989-03-14
Also published as: DE1934168A1; DE1934168B2; ES381428A1; CH503908A; AT296768B; NL7009983A; GB1257897A; BE752772A; FR2054147A5

Abstract

A self-priming lateral channel centrifugal pump having a pair of ribs formed in the suction chamber to enhance the self-priming features of the pump. The fluid traverses a substantial portion of the suction chamber before porting to the impeller, and the ribs are located just in advance of the impeller port. One of the ribs extends radially inwardly of the suction chamber and the other radially outwardly from the inner region of the chamber. The ribs are circumferentially spaced and both extend the entire axial width of the suction chamber and about half the radial depth of the chamber.

Description

United States Patent Hagemann 1 Mar. 14, 1972 [54] SELF-PRIMING LATERAL CHANNEL [56] References Cited CENTRIFUGAL PUMP UNITED STATES PATENTS 1 1 lnvemofl Wall" 8 ltzehoe-Nordoe- 1,269,063 6/1918 De Laval ..415/183 i Germany 3,462,949 8/1969 Anderson et al ....415/1s3 2,051,080 8/1936 Frederick i ..415/53 [73] Assgnee 2 meme Hdmm 3,252,421 5/1966 Luhmann ..4|s/1s2 ermany [22] Filed: July 2, 1970 Primary Examiner-Henry F. Raduazo Attorney-Oberlin, Maky, Donnelly & Renner [21] Appl. No.: 51,918

[ ABSTRACT [30] Foreign Application Priority Data A self-priming lateral channel centrifugal pump having a pair of ribs formed in the suction chamber to enhance the self July 5, Germany ..P p g features of the The traverses a substantial portion of the suction chamber before porting to the impeller, [52] US. Cl AIS/182, 415/213 T and the ribs are located j i advance f the impeller port. [51] Int. Cl ..F04d 29/40, F04d 1/00 One of the ribs extends radially inwardly of the suction [58] Field of Search ..4l5/53 T, 213 T, 217, 182, chamber and the other radially outwardly from the inner re- 415/183, 184, 185 gion of the chamber. The ribs are circumferentially spaced and both extend the entire axial width of the suction chamber and about half the radial depth of the chamber.

5 Claims, 4 Drawing Figures Patented March 14, 1972 3,649,131

2 Sheets-Sheet 1' T F; Fig.1

Patented March 14, 1972 3,649,131

2 SheetS-Sheet 2 SELF-PRIMING LATERAL CHANNEL CENTRIFUGAL PUMP The invention a self-priming lateral channel centrifugal pump with horizontal shaft, a pump inlet situated on the underside and pointing downwards, an annular suction chamber, a port from the suction chamber to the pumping area of the pump, situated to the side of the impeller and on a level with or lower than the shaft and with a dividing wall in the suction chamber, placed between the pump inlet and the port to the pumping area.

The pump covered by the invention is primarily for application in tanks with a dispenser pump for the pumping of automotive fuels, where these have to be pumped up from underground containers. For reasons of price and space, a simple pump design with a fitting that is uncomplicated and that does not take up too much room is necessary. A simple pipe system working at low deformation with as few connections in the pump system as possible is desirable in order to reduce leakage losses of the pumping substance in the dispensing pump.

A further important point is that the pump must be selfpriming without the use of additional auxiliary pumps (e.g., hand pump), valves or nonreturn flaps even for the pumping of fuels that easily gasify; this means that the pump must at any time suck up the gases or vapor of the pumping substance in the pump and the connected pipes after the pump has been filled once, even after considerable periods of shutdown, commence pumping the fluid after the gas has been sucked up and be in a position to pump fluid containing gas without difficulty or interruption.

The aim was to construct a simple design for a self-priming lateral channel centrifugal pump with horizontal shaft, and with a pump inlet situated on the underside and pointing downwards, so that this inlet can be flanged directly onto the intake line leading down to the underground container without the insertion of the pipe bends or other pipe fittings. This positioning of the pump inlet means, however, that after switching the pump off, the greater proportion of the fluid contained in the pump casing flows back into the tank and is thus no longer available for further priming of the pump; this means that special measures are necessary to achieve the ability to self-prime.

A self-priming lateral channel centrifugal pump is known in that form that the pump inlet is situated, as is usual, on the top side which does not enable a simple intake line from an underground container to the pump inlet, but requires, for example, two quarter bends in the intake line. The positioning of the pump inlet on the top side makes it possible that, after the pump has been switched off and the transport fluid falls back into the tank, a sufficient quantity of fluid remains in the pump.

Other pumps are known in that form that normal operation is guaranteed by nonreturn flaps installed in the pump, which prevent the absence of fluid in the pump after switching off.

The solution of the named disadvantages according to the invention is that the pump inlet situated on the underside of the pump leads straight into the suction chamber and that in the inflow direction two ribs are fitted in the suction chamber a short distance before the port; one rib is fitted inthe inner radial area, the other in the outer radial area of the suction chamber. Both ribs cover the entire axial width and about half the radial cross section of the suction chamber.

This positioning of the pump inlet facilitates a feed system with little deformation and with few joints that is easily installable; the placing of the two ribs in front of the port enables good self-priming without the use of nonreturn flaps, valves or similar devices in spite of the fact that the pump inlet points downwards.

Tests have shown that the presence of both ribs is necessary in order to ensure self-priming. The effect of the ribs placed in the suction chamber is that the operational fluid spun out of the channel into the suction chamber by the impeller during the removal of air from the system is collected and fed back to the pumping area through'theport. The rib situated in the inner radial area of the suction chamber also influences the level of fluid in the suction chamber and, together with the rib situated in the outer radial area of the suction chamber, prevents the operational fluid frombeing lost to the suction intake.

According to a further characteristic of the invention, it is useful for the ribs situated in the inner radial area of the suction chamber to be placed first in the direction of flow and for the rib situated in the outer radial area of the suction chamber to follow since a part of the operational fluid supply that is spun out of the port into the suction chamber by the impeller during the removal of air from the system is-caught directly by the outer radial rib and fed back to the pumping area through the port.

According to a further characteristic of the invention, it is useful that both ribs in front of the port be inclined towards this and/or be bent at their radial free end towards the port since the ribs feed the operational fluid that is spun out during the removal of air from the system back to the port and the pumping area as described above, whereas, on the other hand, in normal fluid pumping where the fluid flows from the pump inlet to the port the ribs are. shaped to further flow; this also effects a favorable flow of the impeller segments, so that a better Ah value is provided by the ribs than is to be found in a pump without ribs.

It has also proved advantageous for the direction of rotation of the impeller to be opposed to the direction of flow in the annular shaped suction chamber, since the port from the pumping area to the pressure chamber of the pump is then situated in the lower part of the pump. This proves to be favorable during removal of air from the system, since no operational fluid that reaches the pressure chamber together with the gas is lost.

In order to simplify the structural design of the pumping section, which comprises the pump inlet, the suction chamber and the ribs, the invention proposes that the lateral channel be situated on that side of the impeller away from the port leading from the suction chamber to the pumping area.

The preferred forms of the invention are illustrated in the accompanying drawings, in which:

FIG. shows an overall view,

FIG. 2 and FIG. 3 each show an interior view of the suction chamber of the pump on the Section A-B as in FIG. 1.

FIG. 4 is a section through the casing of the pump on the Section CD in FIG. 3. The arrows with solid lines show the route of the pumping material.

The self-priming lateral channel centrifugal pump 1 in FIG. 1 is in this instance equipped with an elastic motor 2 and shows the pump inlet 3 situated on the underside.

FIG. 2 shows the part of the casing 4 containing the pump inlet 3 with horizontal shaft 5, annular suction chamber 6 and the port 8 situated to the side of the impeller 7. The shorter, direct route of the pumping medium from the pump inlet to the port is barred by a dividing wall 9 in the annular suction chamber, so that the flow has to pass the

ribs

10 and 11 situated in front of the port.

FIG. 3 shows another version of the invention with the same key numbers for the pump components as in FIG. 2. The pump inlet 3 and the

ribs

10 and 11 are situated differently in comparison with FIG. 2 and the arrow with a broken line on the impeller 7 shows its direction of rotation if this is opposed to the direction of flow in the annular suction chamber.

FIG. 4 is a cross section on the line CD in FIG. 3 through the pump casing showing the rib ll partially in section, the rib l0 and the dividing wall 9 in elevation.

The port 13 from the lateral channel 12 to the pressure chamber of the pump is situated in the lower part of the pump, the lateral channel 12 is situated on that side of the casing 4 away from the impeller 7, while the dividing wall 9 and the

ribs

10 and 11 are sealed off laterally by the casing wall 14.

The invention is not restricted to the pumps for tank systems described above. It can be applied in any circumstances where similar requirements have to be met in respect of the arrangement of the pump inlet and of saving space in self-priming pumps.

We claim:

I. A self-priming lateral channel centrifugal pump comprising a horizontal shaft, an impeller mounted on said shaft for rotation therewith, and an intake casing having an annular suction chamber, said casing having a wall separating said chamber from said impeller, a port formed in said wall for directing fluid from said suction chamber to said impeller, said port extending below the level of said shaft, a pump inlet provided in the lower part of said suction chamber, a dividing wall extending transversely in said suctionchamber below said port for preventing fluid entering said inlet from flowing directly to said port, a pair of ribs formed in said suction chamber slightly in advance of said port in the direction of travel of the fluid, one of said ribs extending radially inwardly from the radially outer region of said suction chamber and the other of said ribs extending radially outwardly from the radially inner region of said chamber, both of said ribs extending the entire axial width of said suction chamber and about half the radial depth of said chamber.

2. The pump of claim 1 wherein said other rib situated in the inner radial region of said suction chamber is placed first in the direction of flow and said rib situated in the outer radial region of said suction chamber follows.

3. The pump of claim 1 wherein both of said ribs are inclined at their radial free ends towards said port.

4. The pump of claim 1 wherein the direction of rotation of said impeller is opposed to the direction of fluid flow in said suction chamber.

5. The pump of claim 1 wherein said lateral channel is situated on that side of the impeller away from the port leading from said suction chamber to the pumping area.

Claims

1. A self-priming lateral channel centrifugal pump comprising a horizontal shaft, an impeller mounted on said shaft for rotation therewith, and an intake casing having an annular suction chamber, said casing having a wall separating said chamber from said impeller, a port formed in said wall for directing fluid from said suction chamber to said impeller, said port extending below the level of said shaft, a pump inlet provided in the lower part of said suction chamber, a dividing wall extending transversely in said suction chamber below said port for preventing fluid entering said inlet from flowing directly to said port, a pair of ribs formed in said suction chamber slightly in advance of said port in the direction of travel of the fluid, one of said ribs extending radially inwardly from the radially outer region of said suction chamber and the other of said ribs extending radially outwardly from the radially inner region of said chamber, both of said ribs extending the entire axial width of said suction chamber and about half the radial depth of said chamber.