US2990779A

US2990779A - High speed propeller pump

Info

Publication number: US2990779A
Application number: US705285A
Authority: US
Inventors: Reinecke Hans
Original assignee: Obermaier and Cie
Current assignee: Obermaier and Cie
Priority date: 1956-12-27
Filing date: 1957-12-26
Publication date: 1961-07-04
Anticipated expiration: 1978-07-04

Description

H. REINECKE 2,990,779

HIGH SPEED PROPELLER PUMP July 4, 1961 Filed Dec. 26. 1957 5 Sheets-Sheet 1 INVF N 7' 0,?

Hana PE/NECX E July 4, 1961 H. REINECKE HIGH SPEED PROPELLER PUMP 5 Sheets-Sheet 2 Filed Dec. 26. 1957 \'IIIIIIIIIIII \\\llllllfrlll INVENMP Hans PE/NE'C/(E y 1951 H. REINECKE 2,990,779

HIGH SPEED PROPELLER PUMP Filed Dec. 26. 195'! 5 Sheets-Sheet 3 INVENTOP Hana PE/NEC/(E July 4, 1961 H. REINECKE 2,990,779

HIGH SPEED PROPELLER PUMP Filed Dec. 26. 1957 5 Sheets-Sheet 4 INN INVENTO'Q Hams Pf/NECA E July 4, 1961 Filed Dec. 26. 1957 H. REINECKE 2,990,779

HIGH SPEED PROPELLER PUMP 5 Sheets-Sheet 5 III/III) INVENTOR. Hans RE/MECKE ijnitcd htates Fatent C) 2,990,779 I HIGH SPEED PROPELLER PUMP Hans Reinecke, Frankenthal, Pfalz, Germany, assignor to Obermaier & Cie., Neustadt an der Weinstrame, Germany Filed Dec. 26, 1957, 'Ser. No. 705,285 Claims priority, application Germany Dec. 27, 1956 2 Claims. (Cl. 103-7) The present invention relates to propeller pumps and is particularly concerned with high speed pumps of the type generally known as injection and proportioning pumps.

In'the operation of liquid pumps it is important to observe besides the output quantity per second'also the prescribed pressure and the evaporation temperature which are dependent on one another, because evaporation must be avoided for the sake of safety of operation. The dependency of the pressure on the evaporation temperature is known to exist with every liquid that can be pumped, i.e. every temperature is associated with a predetermined evaporation pressure and vice versa. Exceeding the evaporation temperature and dropping below the associated evaporation pressure causes evaporation to set in at once and consequently, as a result of steam formation in the liquid, unreliability in the output or quantity pumped. In order to obtain unimpeded operation it is, therefore, necessary that the pressure in the supply or feed is maintained to correspond to the associated temperature. If the resistance losses arising in the supply and the velocity are taken into consideration as the pressure is below atmospheric pressure, there is no cause for misgivings from a standpoint of the mechanics of flow because the temperature limit for this pressure is not exceeded. At higher temperatures and correspondingly greater pressure an additional or auxiliary pump unit is needed which first raises the liquid pressure to such an extent that the increase in temperature can be provided by introducing heat by means of steam or hot water without the danger of evaporation. This additional pump unit then requires a special driving or power source.

A special kind of pump unit is also necessary in a supply system where chemical means or color liquids are to be added in relatively small qaunti-ties to a main liquid and when increased temperature and thus increased pressure are needed for the greater efliciency of the method.

In such cases the main pumps are circulation pumps which continuously circulate the contents of the container or vat so that the main liquid is intimately mixed to a sufiicient extent with the additional liquid. This latter liquid must be introduced into the flow circuit of the main liquid at that location where the lowest pressure exists. The introduction of heat may then take place anywhere in the circuit by steam or hot water.

In those cases where the supply is in the form of small quantifies of chemical nature or solutions of .color or dye or where, therefore, the main pump serves essentially for circulating the boiler content, the auxiliary pump will haul only relatively small quantities. Then it must at the same time replace all losses due to leakage or escape, for example at stiffing boxes, valves, drains, etc. These losses can be kept low in a manner known per se. In any given case it is also possible to use other means for this purpose instead of special pumps such as, for example, compressed air containers, accumulators and the like which, however, require additional controls and suflicient space in order to be safe in all cases.

The invention is based on the concept of uniting a main pump with an auxiliary pump into a commonly driven machine unit. The main hauling for the large quantities to be pumped to small heights is performed in this case 2,990,779 Patented July 4, 1961 ice by a high speed propeller pump, while a slowly rotating circular pump for smaller supply quantities structurally combined with the same takes over the increase of pressure to relatively high lifting heights. In this connection the liquid space of the circular pump fills the inner core of the rotor of the propeller pump and reaches to the outer wall of the hub of the rotor which is provided either with bores leading into the rotor channels or it has paddles with tubular members welded thereto which extend from the inner hollow space into the outer zones of the rotor channels and thus obtain further increases in pressure, which are imparted to the liquid hauled by the propeller pump and thus prevent the development of vapor.

It is, therefore, a principal object of the invention to simplify the construction of injection or proportioning pump installations by combining several pumps into a single unit.

It is a further object of the invention to improve the performance and efficiency of such pump installations.

Further objects and advantages of the invention as well as structural details of the same will become apparent from the following description of the embodiments of the subject of the application illustrated in the drawings in which FIG. 1 is a longitudinal cross section through the new pump assembly unit taken parallel to the axis with the pressure stub arranged radially,

FIG. 2 is a main longitudinal section taken parallel to the axis of a somewhat dilferent assembly, likewise with a radially arranged pressure stub,

FIG. 3 shows a further embodiment in longitudinal cross section taken parallel to the axis with the two stubs extending in axial direction concentric with the center axis,

FIG. 4 shows the main cross section of FIGS. 1 and 2.

FIG. 5 shows a further advantageous embodiment of a pump in longitudinal cross section,

' FIG. 6 is a vertical section taken through the rotor to show the apertures circumferentially of the rotor cylinder, and

FIG. 7 is a vertical section of the rotor showing tubular passages" through the paddles connected to the circumferential apertures.

The flow of the main pump generally indicated at A which has a housing B enclosing a rotor C having inner and outer cylindrical walls is from feed channel 1 to pump channel 2 or vice versa and thus does not change over from one cross sectional area to a different cross sectional area. The lifting height is primarily obtained by inverting the flow. The flow of the auxiliary pump passes from the independent supply tube 3 by way of interior passages 5 and radial walls 6 of rotor hub 4 and apertures 7 and is either in communication with the rotor channels by way of apertures in the form of bores 13 or with the outer zones of the rotor channels by way of apertures including the welded on tubes 12. In this latter case, where the welded tubes 12 are used the pressures imposed upon the flow are considerably greater than when the direct bores 13 are used.

As shown in FIG. 6, the walls 6 form paddles which constitute a centrifugal pump, force auxiliary fluid through apertures 1-3 into pump channel 2 and increase the pressure of the fluid pumped by paddles 9. The tubular passages 12 shown in FIG. 7 connecting with the apertures 13 increase the pressure produced by the paddle walls 6 and thereby the pressure in channel 2 as compared to the pressure produced by the arrangement in accordance with FIG. 6.

The temperature of the liquid pumped by the pressure increasing pump is maintained, if possible, evenly below the evaporation or gasification point until this liquid is absorbed in the operating liquid. For that reason the pressure increasing liquid must be protected against absorption of heat above all from the operating liquid, if need be, by air insulation (see FIGS. 1 and 3).

In particular the following considerations are submitted for the explanation of the subject of the invention:

High velocity is a criterion for hydrodynamic machines which indicates the magnitude of the velocity of the liquid element with respect to the velocity of the rotor surfaces which imparts energy to the liquid in the form of static pressure and velocity.

' The greater the velocity, the more sensitive is the pump against an increase in the quantity pumped and the temperature, i.e. sensitive against increasing velocity an decrease in the feeding pressure.

This applies only for normal pressure and temperature conditions which are not in the immediate proximity of any vaporization or gasification.

The conditions change immediately if it is necessary to operate with higher temperatures than those which correspond to normal pressure conditions or with correspondingly lower pressures. The specific weights and the other characteristics of the operating liquid change in that event in such a manner that normal computations are not sufiicient to determine the results. In such cases it is necessary to change the pressure level in a manner that such computations will again apply. The change of the pressure level is effected by shifting the machine into a different level or altitude condition, i.e. downwardly, which increases the pressure level, by an additional gas or air pressure which is effective upon the liquid, or by a particular pressure increasing pump which is suitably connected at a location of low pressure in the system so that the pump pressure replaces the low pressure in the system. The pressure increase then corresponds to the differential between the'two pressures and correspondingly increases the entire pressure level.

The pressure produced by the pressure increasing pump is so strongly dependent on the quantity of liquid pumped because this pump is designed for a small capacity flow.

The locations of losses are, above all, the stufiing boxes and other causes of leakage. To this is added the necessary feeding back of the operating liquid to the feeding container for the purpose of maintaining a ci-rcu-' lation which due to the heat carried along is to be cooled down to the temperature of supply.

Due to the small consumption of power, the pressure The arrangement of the pump rotor in accordance with FIG. 1 with supply from the outer space inwardly reas is ordinarily the case with such pumps, but rather decreases, while the pressure increases.

The inward flow can take place at 1 or 2, depending on the use, and the direction of flow and of rotation corresponds thereto. Normally the flow would be in the direction from feed channel 1 to pump channel 2 and the pump channel 2 would be provided with an increase in pressure depending on the type of paddles or fans.

The pressure increasing means provided comprises a supply tube 3 and the inner hollow space 5 of the rotor 4 which is connected with the supply tube 3 by way of aperture 7. The interior of the hollow space 5 is provided with walls or ribs 6 which impart the rotation of the rotor 4 to the mass of liquid and thereby effect an increase in pressure from the supply tube 3 to the outer diameter of the rotor 4.

The liquid enters the housing at 8 and at 1 flows onto the rotor 4 having paddles 9, entering the pressure space of the housing at pump channel 2 and flowing into the pressure conduit at 10. The paddles 9 transfer the output from the drive shaft 11 to the liquid and impart to it in addition to a static pressure a certain velocity which is converted to some extent into pressure in the housing chamber 2.

The bores or tubes 12' in the paddles aid in increasing the pressure of the pressure increasing pump to the required amount but only when particular requirements are made of the pressure increase, while normally the pressure increase is already attained at the outer bore 13 of the hub. When the direction of operation is reversed the liquid flows from '10 to 2 and then through the channels between the paddles 9 to 1 and out again increasing pumps are of relatively small dimensions, and

for that reason strongly sensitive to increases in the quantities pumped. It is therefore necessary to endeavor maintaining the aforementioned losses in the quantity as low as possible.

It is a requirement for the pressure increasing pump to maintain the liquid pressure always at such a level thatat the location of lowest pressure in the system operation is never below the gasification or evaporation pressure. On the contrary, it is necessary to aim at the inclusion of a certain safety factor of approximately 15% against incidents which might cause interference or breakdown.

The relationship of the pressures produced with the pressure increasing pump to the pressures necessary for pumping with the high velocity pumps must be approximately a multiple of 4 to 8 or even 12.

Accordingly it is a further characteristic feature of the invention that the pressures produced by the propeller pump are substantially lower than those of the liquid quantities introduced in the interior of the rotor by the centrifugal pump which serves for increasing the pressure level at higher temperatures, which thus take over the increase in pressure by superimposing this pressure upon the lifting power of the propeller pump at the connecting bore between the two spaces, i.e., between the space for the pressure increase and the space for the propeller pump.

through the outer conduit or stub 8.

The side of the rotor remote from the drive shaft 11 may be provided with paddle means 18 comprising radial ribs of small height which serve the purpose of preventing pressure liquid from the pressure space of the pump reentering the hollow space 5 of the pressure increasing pump through the packing gap 17.

A particularly advantageous embodiment of the pump housing is illustrated in FIG. 3 in connection with the pump rotor design in accordance with the invention. The intake is arranged radially of the rotor and takes place from a concentric or spiral housing space the entrance diameter of which to the pump is greater by about 5% or more than the outer diameter of the rotor. Subsequently the liquid stream is guided into the axial entrance cross section of the paddle of the rotor. The length of the paddles and the angle of the paddles determine the lifting height desired. The power consumption of the pump is considerably smaller than with the normal propeller pumps where it far exceeds that for normal consumption for small quantities pumped.

The use of several pressure stages of the rotor of the propeller pump is provided for in a further advantageous embodiment of a pump in accordance with the invention. The delivery head is here subdivided into two stages where the second pressure stage is inserted radially ahead of the first pressure stage. A reversing area is provided in the housing between the two stages in which area vanes may be provided, the angular position of which is adjustable.

Such a pump is illustrated in FIG. 5. In the direction of flow the entrance of the liquid into the first stage is at feedchannel 1, and the vane of the rotor of the first stage is identified at 9. The reversing of the liquid into the second pressure stage is effected in the space 21 vvhichis also provided withvanes which may be angu-.

larly adjustable. The vane of the second pressure stage is identified at 22. After passing therethrough, the liquid is discharged into and from pump channel 2. For connecting the pump an intake stub 8 is provided and a discharge stub 10. In reversing the conveying direction the intake stub 8 becomes the discharge stub, and the discharge stub 10 becomes the intake stub.

The introduction or injection of the additional liquid is effected as in the other embodiments of the pump through tube 3 into the interior passage 5 of the hub of the rotor 4 of the propeller pump which is subdivided by walls or ribs 6. The supplementary liquid enters from the center through the apertures 7 into the passages 5 and flows from there through bores 13 or to tubes 12 connected thereto, preferably into the space of the second pressure stage. If need be, suflicient pressure increase may be obtained already in the first stage at the bore of the hub at 13.

Having now described my invention with reference to the embodiments illustrated in the drawings, I do not Wish to be limited thereto, but what I desire to protect by Letters Patent of the United States is set forth in the appended claims.

I claim:

1. High velocity reversible drive propeller pump for raising large quantities of water to small heights, contprising a pump housing having a pump channel, a rotor in said housing having a hollow cylindrical hub mounted on a drive shaft, a stationary auxiliary liquid supply tube connected to the center of said hub, a plurality of rib paddles extending radially in said hub and defining interior passages, a plurality of main paddles disposed circumferentially and extending radially of said hub into said pump channel, a plurality of apertures provided in generally radial alignment along the inner and the outer cylindrical walls of said hub intermediate said rib paddles, and tubular passages extending radially through said main paddles from said apertures in the outer cylindrical walls to the Wall of said pump channel, said hollow hub including said interior passages, said rib paddles and said apertures constituting a small capacity centrifugal pump capable of injecting auxiliary fluid into water pumped by said main paddles to increase the pressure head of the water pumped by said main paddles, said rotor having a plurality of relief paddles in the form of rior passages, a plurality of main ribs extending from the side of said rotor remote from said shaft and proximate said auxiliary liquid supply tube.

2. High velocity reversible drive propellerpump for raising large quantities of water to small heights, comprising a pump housing having a pump channel, a rotor in said housing having a hollow cylindrical hub mounted on a drive shaft, a stationary auxiliary liquid supply tube connected to the center of said hub, a plurality of rib paddles extending radially in said hub and defining intepaddles disposed circumferentially and extending radially of said hub into said pump channel, a plurality of apertures provided in generally radial alignment along the inner and the outer cylindrical walls of said hub intermediate said rib paddles, and tubular passages extending radially through said main paddles from said apertures in the outer cylindrical walls to the wall of said pump channel, said hollow hub including said interior passages, said rib paddles and said apertures constituting a small capacity centrifugal pump capable of injecting auxiliary fluid into water pumped by said main paddles to increase the pressure head of the water pumped by said main paddles, said rotor having a plurality of relief paddles in the form of ribs extending from the side of said rotor remote from said shaft and proximate said auxiliary liquid supply tube and said main paddles each consisting of two paddles arranged radially with respect to each other and forming two pumping stages, and redirecting means having guide vanes operatively associated with said paddles'for directing the pumped fluid from one pumping stage to the other, said tubular passage terminating in the outermost paddle adjacent the pump channel wall.

References Cited in the file of this patent