US2319228A - Vacuum pressure pump - Google Patents

Description

May 18 43 L. B. HARRINGTON VACUUM PRESSURE PUMP Filed May 10' 9.40

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41 7 22m: IZEZA'MW'aL Jag-3 ttorneys May 18; 1943 L. a. HARRINGTON 2,319,223

VACUUM PRES SURE PUMP Filed May 10, 1940 v; 4 Sheets-Sheet 2 Z 22 fi...

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y 1943 L. HARRINGTON 2,319,228

VACUUM PRESSURE PUMP' Filed May 10, 19 1 0 4 Sheets-Sheet s as'r iarrizym 9L mu,

3nnentor y 8, L. a. HARRINGTON 2,319,228

VACUUM PRESSURE PUMIf Filed May 10, 1940 '4 Sheei-Sheet 4 las'lr "for attorney- Patented May 18, 1943 UNITED} STAT-ES? PATENT OFFICE forty per cent to Reynolds 'Allen, Salem, and fifteen 'per cent to Clay A. Racely, Portland,

Oreg.

Application May 10, 1949, Serial,No.,33 4,43 ?1 Claims. wrest-103 The present invention relates .to improvements in vacuum pressure pumps-and is a continuation in part of my prior forfeited application entitled Rotary vacuum pump, filed November 25, 1938, Serial No. 242,300.

An object of the invention is toprovide a pump useful for creating vacuumor-pressure in which a high degree of vacuumlor pressure maybe created by an extremely simple physical construction of pump designed to be operated at a low maintenance rate.

Another object of the invention is to provide a pump of this character composed of few and simple parts simply arranged and combined to yield high efiiciency in .producing vacuum or pressure in a highly economical manner.

The invention has for a further object. to provide a pump useful in refrigerators and-in refrigeration apparatus, vacuum tube manufacture devices, low. pressure physical and chemicalresearch machines, low pressure food packing plants, etc.

A still further object of the invention is to provide an improved vacuum pressure pump in which the construction promotes an increase in the velocity of a liquid moving through a closed conveyance by the application of. centrifugal force.

With the foregoing and other objects inview, the invention will be more fully described hereinafter, and will be more particularly-pointed out in the claims appended hereto.

- In the drawings, wherein like symbols refer to like or corresponding parts throughout the several views,

Figure 1 is a side elevation, with parts broken away and parts shown in section, of a pump rotor constructed in accordance with the present invention. 1

Figure 2 is atop plan view of the same.

Figure 3 is a side elevation, with parts broken away and parts shown in section, illustrating a modified form of the device.

Figure 4 is a similar view showing a further modification.

Figure 5 is a top plan view, with parts broken away and parts shown in section, of the form of the device illustrated in Figure 4.

Figure 6 is a vertical sectionshowing a still further modified form of the device, and

Figure 7 is a fragmentary longitudinal section through one of the discharge tubes showing the vena contracta and the method of entrainment of the vapor in the liquid.

Funnel l rotates on its vertical axis in -a confined liquid 5 and raises a portion of that liquid 'into'rotating tubes 2, 2 securely inserted in rotating .disc -3-of which funnel l is a part. The centrifugal force of the rotating tubes 2, 2 increases the velocity of the liquid moving out through the-passages in the tubes, thus producing a vacuum which communicates with the hollow shaft 4, whichis securely attached to the center of the-top of rotating disc 3. The power for rotation is transmitted to disc 3, tubes 2, 2 and funnel l by shaft 4. The liquid 5 is discharged from the tubes 2, 2 and falls to its original position maintaining a constant volume of available liquid. In Figure 2 the tubes 2, 2 are shown inserted at a tangent to the perimeter of the opening in disc 3 at 6, to facilitate the action of the centrifugal force on the liquid after it enters the tubes 2, 2. i The pump is designed to produce a vacuum as a result of the application of centrifugal-force to two-principles of vacuum production in 'com-- bination, one with the other. The construction of tubes 2, 2 is the necessaryprerequisite to the successful utilization of the above mentioned principles: namely, (a) the reduction in pressureof afmoving liquid on its containing walls with an increase in velocity of the moving liquid brought about by restrictingth cross sectional area'of the conveyance at point I, and (b) the production of a vacuum behind a column of liquid in the distal portion 8 of tube 2 as the mass of the liquid and the rotational acceleration' of the rotating tube produce a force out radially from the center of rotation against the atmosphere.

The rotating funnel l transmits energy in the form of centrifugal force to the liquid at 9 result-- ing in pressure of the liquid against the walls of the funnel The impellers lil attached to the walls of funnel I also raise the liquid up to the cavity 5 by the rotation of this wedge in the liq-i uid as moved bythe anti-clockwise rotation of the disc. As th force increases with the speed of rotation of the liquid the force on thewall of the funnel become sufiicient to raise'the'liquid to 6 where the tubes enter the cavity of the funnel I. Here the force on the'liquid moves the liquid into the restricted portion 1 of tube 2 where the restriction of the cross-section of the conveyance produces an increase in velocity of the moving liquid in addition to the increase of velocity of th liquid as a result of the increasing rotational acceleration as the liquid moves farther from the center of rotation to point II. At this point H where the velocity is at the ideal ratio to the vol ume of liquid which can enter the tube at the opening I3, the pressure reduction resulting from this increased velocity is at a maximum. The gas inlet port I2 enters the chamber I3 and connects with the hollow shaft 4 where the vacuum may be transmitted to another vessel by a suitable valve attachment. As the liquid leaves the nozzle at it is forced against the distal wall of the chamber I3 where it accumulates until the volume is great enough to cover the distal opening of the chamber at I4. Here the centrifugal force moves the liquid out the distal portion of tube 2 at 8. In this region the centrifugal force of the moving liquid is increased constantly as the distance 'ofthe liquid from the center of rotation becomes greater. Th accumulated force of all the liquid in 8 is exerted out radially from the center of rotation against the outer atmosphere thus transmitting a decrease in pressure to the chamber I3 wher a low vacuum is a result of the additive effects of the increase in velocity at the nozzle I I and the increase in centrifugal force beyond chamber I3.

The volume of the liquid in the distal portion 8 of tube 2 is always sufficient to maintain a seal against the pressure of the atmosphere at the end of the tube at point I5. As the liquid is expelled at point l5 it leaves on a line tangent to the circle described by the rotation of the ends of the tubes and is reflected by a suitable containing vessel to the original volume of liquid 5. Thus the liquid describes a complete circulation through the pump with no loss allowing the use of a limited constant volume of the liquid sufficient to maintain th level of the liquid above the opening of the funnel I at 9.

The shaft 4 transmits power to rotate the disc 3, tubes 2, 2 and funnel I, and is constructed with an opening longitudinally through the center through which the gas ports I2 and the inlet tubes I6 communicate the vacuum. to an easily available location II where suitable valves are used to connect to other stationary containers.

Referring more particularly to Figure 3 the liquid chamber is represented at I8 and acts as a container for the liquid medium which is circulatedthrough the pump to create the vacuum or pressure. This liquid chamber I8 is formed in the lower part of a casing or housing I9 to which is attached as by bolts 28- a mounting plate 2| and a housing cover or upper casing section 22. The mounting plate carries the electrical or other motor, of which the field coils or stator are represented at 23 and the armature or rotor at 24. The armature is affixed to a shaft 25 carrying at its lower end a flange 25 which carries by means of bolts 2! the disc 28 which is the rotor of the pump.

In this rotor 28 are provided one or more passages composed generally of the proximal end portions 29 and the distal end portions 30. The proximal end portion 29 is in communication at its inner radial portion with the internal space of the liquid chamber I8 from which it constantly receives its supply of liquid. This proximal end portion 29 is of comparatively small axial length as compared with the axial length of the distal portion 30 of the tube, which distal portion 38 is of increasing diameter from its inner to its outer discharge end.

The inner end portion of the distal part 30 communicates adjacent the proximal end portion 29 with the fluid inlet 3| which opens through the top of the rotor 28 and is in communication with a fluid supply passage 32 extending up through the shaft 25 and laterally through the mounting plate 2| as indicated at 33. This passage 33 communicates with a refrigeration apparatus or with some other vacuum necessity. The diameter of the proximal end portion 29 is preferably less than that of the immediate adjacent part of the distal end portion 38, and this condition is advantageously secured by a step 34 in the passage in order that the stream lines of the liquid being drawn from the supply chamber I8 may form opposite the fluid inlet 3| a suitable vena contracta in which the increase in velocity of the liquid flow axially outward of the tube at this point will develop a low pressure area in and about the fluid inlet 3 I.

From the vena contracta the liquid as it moves axially outward in the distal end portion 30 will enlarge in diameter as limited and restricted by the diametric limits of such distal end portion 30. Inasmuch as this distal end portion 38 is of progressively larger diameter toward the outer end thereof the outwardly moving liquid will constantly expand into increased diameter and the volume of liquid per unit area will increase with a proportionate decrease in velocity, which will result in an increase in pressure in accordance with Berno-ullis theorem.

Such increase in pressure will devolve upon the area about the fluid inlet to create an additional low pressure or vacuum pull over and above that created by the vena contracta. This increased volume of liquid created by the constantly expanding diameter of the distal end portion of the passage is accelerated in its outward motion by the centrifugal force incident to the rotation of the disc or rotor and this acceleration of this increased fluid volume adds enormously to the creation of low pressure in and around the fluid inlet.

In this respect, in accordance with the present invention there is utilized the more effective and controllable action of centrifugal force in creating this accelerating action upon the fluid volume of the motivating medium of the pump.

However observation of the action in the present invention in which the movement of the liquid medium is horizontal and centrifugal and where water, oil, carbon tetrachloride, or mixtures of miscible liquids are employed as the pumping medium, indicates that there is an entrainment of the fluid drawn in through the fluid inlet 3| into the liquid stream in which the piston action of the Sprengel pump and the entrainment action of Bernoullis theorem are combined.

The return tubes 35 are shown in Figure 3 as being coupled in a substantially closed cycle with the discharge tubes. At one end each tube 35 is disposed opposite the outer discharge end of the distal portion 30 of a discharge passage, while the other end of the return tube 35 communicates with the liquid supply chamber |8 and'the circuit of the liquid through the discharge passages and the return tubes is substantially indicated by the chain of arrows in Figure 3.

Contrary to the action in a Venturi tube or meter, there need be no substantial head or pressure of the liquid at the proximal end portion 29. In fact the low pressure side of the device is in the chamber l8. That is the chamber pressure is lower than the pressure in the casing I9 outwardly of the discharge passages of the rotor; but of course the pressure in the chamber I8 is not as low as that in and about the vena contracta which is the lowest point in the system. While the liquid pump medium circulates the distaljportions 30 to centrifugal action'which through the return tubes 35 the vapor separates from such liquid at the discharge mouths. or nozzles of the discharge passages and ascends upwardly as indicated by the arrow chain through orifices 36 in the mounting plate 2| and up into the roof of the housing cover 22 which thereby becomes a pressure chamber. An outlet for the pressure chamber is indicated at 31 from which the compressed vapor is led off to a condenser and from the condenser the condensed. vapor is cycled through the refrigerating system back to the compressor.

The pumping liquid medium is also utilized for lubrication purposes by the use of a lubricant duct 38 having its origin in a point disposed concentrically and centrifugally external of the mouths or nozzles of the discharge passages 29, 30, that is concentrically outside of the perimeter of the disc 28 where it is positioned to receive under pressure the discharge of the liquidmedium from the discharge tubes with sufficient force to raise this liquid in the riser part'of the duct 38 from which it is carried over in the horizontal branch of the duct and thence is liberated into a lubricant supply reservoir 39 provided in the upper portion of the shaft 25. This reservoir communicates with lateral ducts 40 which will whirl the liquid out centrifugally and into the bearing spaces between the shaft 25 and its bearing member 4|.

Reservoir 39 will overflow. The overflow liquid will be whirled out by centrifugal force and will descend upon the field coils 23 having a cooling effect on the same, after which such liquid will drip down upon the mounting plate 2| and descend through the orifices 36 into the pump chamber. In fact this liquid will drip down through the openings 36 substantially into the liquid medium which stands at a height in the pump chamber l8 up to the mounting plate or at some level approaching .the same with the rotor 28 immersed, although the pump will act Where the rotor is not immersed entirely. However I prefer to immerse it.

In Figure 3, 42 indicates the insulated terminals for the electric leads to the windings 23 and 24.

As previously explained the action of the present pump, and the principle of operation on which it is based, depends upon the tractive'effort developed by the liquid pistons or volume of liquid bodies moving outwardly in the discharge tubes 29, 3!]. The effort is on the downstream side of the device taking the fluid inlet 3| as the intermediate area to be eifected by the pumping action, and this principle of operation differs from the Venturi tube in that a head of pressure is utilized in the Venturi action to drive the liquid from the up-stream side through the narrow neck or vena contracta and thence outwardly through the down-stream side of enlarging diameter. In other words in the present pump the liquid is pulled through the discharge tubes from points radially outward of the vena contracta. This tends to create areas of -vacuum back of the liquid pistons in the distal portions 30 of the discharge passages instead of the pressure arrangement in the Venturi meter for driving such liquid outwardly in the down-stream side of the passage. While the enlarging diameter of the distal portions 30 of the discharge passages allowing of an increased volume of the liquid slows the movement of such liquid, the fact that the discharge passages are carried by the rotor 28 enables me to subject the liquid in offsets thetendency oflthe. liquid to lag in the discharge fpassages' and. actually accelerate the movement of the liquid pistons or liquid body as it moves outwardly in the distal portions 30. This acceleration of movement due to centrifugal forcezgreatl-y increases the production of the vacuum.

The dischargepassages may be of any desired crosssectional configuration and they may be directly radial with respect to the rotor 28 and itsaxis ofrotation but preferably these discharge passages 29, 30 will be set at an angle to the radiusand in fact may be set in any position between the radius and a tangent to the liquid chamber, or these discharge tubes may be curved, and the use of the expression radial or generally radiaP-"in the claims will be understood to cover these variations;

Referring more particularly to the form shown in Figures 4 and 5y'the main difference between this form of the invention and that shown in Figure 3 is the-elimination of the return tubes of Figure 3 and thearrangement of a base member 43 having cast or otherwise mounted therein fins or vanes 44. These-vanes 44 are curved as shown in Figure 5 relatively toth'e clockwise direction of rotation of the rotor 45 for the purpose of encountering the liquid inits rotary motion established incident to the rotation of the rotor 45 and guiding such liquid into the central zone-ofthe-interior space'within the casing or housing with which the liquidchamber 46 communicates. The tendency of therotor 45 would be to throw out the fluid against the outer walls'of the chamber and to create a partial vacuum at the central zone of the chamber; In other words the action of the rotor alone-would beagainst cyclingtheliquid from the outer ends of the discharge tube back to the chamber 46 and into the proximal portions 29 of such'discharge tubes.

Inthis form of the invention the casing 41 is shown as'extending down to the base 43 to which it'is' attached removably by' appropriate fastenings 48.

While there are some other points of difierence in design of this device the essential parts "are substantially thesame as illustrated in Figure 3 and are so numbered. Referring more particularly to Figure 6, a casing andbase is herein shown made of stampings in which represents, the base stamping to the upper marginal edge of which is welded or otherwise aflixed a second ring stamping" 50. The upper rim ofthe ring 50 is turned inwardly. to providea flange 5! upon which .are supported the field coils 52 of the electric motor. Bolts 01'' other fastenings 53 are engaged with the'field coils 52 and the flange 5| to maintain the field coils in place. At 54 is shown a baffle ring which may also be made of stampings secured together in .a hollow formation. This ring has a curved lower wall '55 which conforms in a very general waylto the curvature of the base 49 and leads from a point adjacent the mouths of the discharge passages downwardly and around to the central zone beneath the fluid chamber 56 in order to form passages 51 for the'circulation of the liquid andto prevent eddy currents being set up in the liquid which would interfere with good cycling action and loss of energy.

The battle ring 54 is supported in any suitable manner directly below the disc or rotor 58 and the lower wall is stream-lined in conformity with the stream-lining of the upper portion of the rotor 58 to reduce the eddy currents and to prevent trapping of the gas beneath the disc. Spider arms 59 are shown as spanning the distance between the side of the base 49 and the bafiie ring 54 in order to support the latter.

The chamber 56 is vented by means of one or more orifices 60 to carry olT any pressure that would tend to be built up in the upper portion of the liquid chamber 55. When the pump is pumping vapor such vapor becomes entrained with the pumping liquid and is apt to accumulate in the upper portion of the chamber 56 with undesirable results and the orifices 60 are provided to liberate this vapor and to carry it off from the upper part of the chamber 56.

In this instance the disc 58 is supported by bolts or other fastenings 6| which depend from a flange 62 of shaft 63. This shaft rotates within a bearing member 64, the bearing being supported by a flange 65 beneath and made fast by fastenings 66 to a ring 61 which is also a stamping and which is welded or otherwise secured to the ring 50. The ring 61 is formed with openings 68 adjacent apertures 69, the openings and apertures permitting of the liberation of gas and vapor in the pump chamber to ascend freely into the overhead space contained within the enclosing cap housing 10.

The mounting of the discharge passages upon a rotor and the rotation of the-rotor to subject the passages to centrifugal action enables me to shorten these passages greatly in an axial or radial sense as compared with lengths of Venturi tubes or meters; the rotary centrifugal action tending to forcibly throw out the liquid pistons or liquid bodies and the farther from the center of rotation the greater this centrifugal action so that by virtue of the centrifugal force the movement of the liquid radially outward in the passages is accelerated.

The outer ends of the discharge passages may open outwardly to atmosphere but usually the outer or discharge ends or muzzles of the passages will be immersed in the liquid body within the pump casing or within the rotor chamber and the pressure in such rotor chamber will usually be in excess of that of the atmospheric pressure.

One convenient setting of the discharge passages is the arrangement in which the axis of such passage is substantially at a tangent to the outer portion of the liquid chamber, such arrangement being shown in Figure l, but as heretofore stated the axis of such passages may be set either radially to the rotor or at any desired angle or through a range of angular distances from the radius to a tangent to the fluid chamber.

In Figure 7, H shows the vena contracta which is formed in the liquid by the orifice 29 forming the proximal end of the discharge passage. This figure shows the stream-line path of the liquid and also shows the expanding of the liquid in the inner part of the distal portion 30 of the passage. At 12 are indicated globules of vapor which have been drawn in through the fluid inlet 3L The fluid is moving in the direction of the arrow 13. The arrows 14 show the outward direction of the pressure in all directions. The discharge end of the passage is indicated at 15. The arrows 14 indicating the direction of pressure show the high sealing efiect given by the liquid in the distal portion 30.

The same principle of operation prevails in all the forms of the invention shown inthe drawings. While the discharge passages of Figures 1 and 2 are shown to be provided within so-called tubes 2 the passages are in reality in the rotor in the same manner as the passages 29, 3B of Figure 3 and of the other figures. In fact there are passages in the rotor in Figures 1 and 2 and the tubes 2 only form liners for the passages and outer extensions of the same. Moreover the tubes 2 of Figures 1 and 2 rotate with the rotor and are therefore a part of the rotor. The words discharge passages in the claims are intended to cover all the forms shown.

It is obvious that various changes and modifications may be made in the details of construction and design of the above specifically described embodiment of this invention without departing from the spirit thereof, such changes and modifications being restricted only by the scope of the following claims.

What is claimed is:

1. An improved pump comprising a central rotatable member having a liquid chamber therein, a funnel extending down from said chamber and member and in open communication with a body of liquid supply, said funnel having an inner tapering wall tapering towards said chamber whereby the diameter of the funnel is smaller at its inlet end and larger at said chamber end, fins in the tapering internal wall of said funnel shaped and positioned to move the liquid on rotation towards said chamber, a passage in said member with its proximal end of a reduced diameter and in communication at its inner end with said chamber and having its distal end of increased diameter and open to atmosphere, and a fluid inlet communicating with the passage adjacent its proximal end.

2. An improved pump comprising a pump casing containing a body of liquid, a rotor in the casing having a chamber at its central part, means to drive the rotor, said rotor having passages substantially radially'arranged opening at their inner ends into said chamber and at their outer ends into the outer part of the casing, vena contracta in said passages, said passages being of enlarging diameters radially beyond said vena contracta, and return tubes having their initial ends substantially concentrically disposed opposite the mouths of said rotor passages and with their opposite ends disposed adjacent said chamber, and fluid inlets to the vena contracta.

3. An improved pump comprising a pump casing containing a body of liquid, a rotor immersed in said liquid, means to drive the rotor. said rotor having a substantially central chamber and substantially radial passages, means in the passages for forming vena contracta, said passages having an enlarging diameter beyond the vena contracta, a fluid inlet to the vena contracta, vanes in the casing reverselycurved with respect to the direction of rotation of the rotor to cause the liquid ejected from the mouths of the passages at the perimeter of the rotor to be moved centrifugally' towards said central chamber.

4. An improved pump comprising a casing for a body of liquid, a rotor in said casing and liquid having passages therein, means in said passages to form vena contracta, said passages, of enlarging diameter outwardly of the vena contracta. a liquid chamber in the central part of the rotor opening downwardly into said casing, a fluid inlet to the vena contracta, means to rotate the rotor, a baffle ring beneath the outer part of the rotor, said baflie ring and the opposed portion of the casing being mutually curved from the discharge ends of the tubes to said chamber, and means to support the baflle ring without impeding the cycling of the liquid from the discharge ends of the tubes to the chamber and the inner ends of the passages.

5. A vacuum pump comprising a rotor having a central liquid supply chamber and non-radial passages extending from said liquid supply chamber to and through the outer peripheral edge of said rotor with the outer discharge mouths of the passages trailing the direction of rotation of the rotor, said passages each composed of axially short proximal portions and axially long distal portions, both said portions being in substantial alignment on the axis of the passage, the distal portion of the passage having at its innermost part a space communicating angularly with a source of vacuum and having a diameter greatly in excess of the diameter of the proximal passage portion to induce the formation of a vena contracta in the liquid moving from the proximal to the distal portions of said passage with the vena contracta forming an annular fluid channel in said space, said proximal portion being of progressively increasing diameter from said space to the mouth of the passage.

6. An improved vacuum pump comprising a rotor having a central liquid chamber and a passage opening with its mouth at the outer portion of the rotor and communicating at its inner end directly with said central liquid chamber, said passage being ofiset from the radius of the rotor and having its axis substantially in a straight line from the chamber to the mouth, said passage composed of an inner axially short proximal portion and an outer axially long distal portion,

tion, whereby to induce the formation of a vena contracta in the liquid flowing from the proximal to the distal portions, the innermost part of the distal portion forming an annular channel about the vena contracta, said rotor having a port from a fluid source entering angularly said annular channel, said distal portion being of progressively increasing diameter from said channel to the mouth of the passage.

'7. A vacuum pump according to claim 6 in which the central liquid chamber is in axial alignment with said passage.

8. A vacuum pump according to claim 6 in which the vena contracta is close to the relatively slow moving center of the rotor.

9. A vacuum pump according to claim 6 in which the distal portion of the passage is made in sections of differential diameter, the larger diameter being in the annular channel and the smaller diameter being outwardly beyond said channel.

10. An improved vacuum pump comprising a rotor having a central liquid chamber, and a passage opening with its mouth at the outer portion of the rotor and communicating at its inner end directly with said central liquid chamber, said passage composed of an inner axially short proximal portion and an outer axially long distal portion, said distal portion at the point where it joins the proximal portion being greatly enlarged in diameter over the diameter of said proximal portion, whereby to induce the formation of a vena contracta in the liquid flowing from the proximal to the distal portions, the innermost part of the distal portion forming an annular channel about the vena contracta, said rotor having a port from a fluid source entering angularly said annular channel, said distal portion being of progressively increasing diameter from said channel to the mouth of the passage.

LESTER B. HARRINGTON.

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