US1926113A - Propeller type blower - Google Patents

Description

septo 12, 1933. H, E SCHMIDT I 1,926,113

PROPELLER TYPE BLOWER l Filed May 14, 1928 2 Sheets-Sheet l Fail,

" -4 INVENTOR 'O5 w 'if H.E5chm|d L 'f @MM-Q L ATTORNEY b Sept. 12, 1933. H, F, SCHMIDT PROPELLER TYPE BLOWER Filed May 14, 1928 2- Sheets- Sheet 2 es I INVENTOR HJiSchmdT CL. V,

ATTORNEY Patented Sept. 12, 1933 UNITED STATES PATENT OFFICE 1,926,113 PRoPELLEn TYPE BLOWER Henry F. Schmidt, Lansdowne, Pa., assignor to Westinghouse Electric & Manufacturing Company, a corporation of .Pennsylvania l Application May 14, 1928. Serial No. 277,650

Claims.

. having an improved form of guide vane, whereby the air motivated by the propeller of the blower is directed toward its outlet with a minimum loss in kinetic energy, and whereby the propeller and the prime mover are rigidly retained in the blower casing.

It has for a still further object to provide an arrangement of propeller, prime mover and blower casing which will permit ready removal of the prima mover while permitting the blower casing to remain secured to its supporting structure.

It has for a still further object to provide a blower embodying an improved form of lubricating system, the reliability and effectiveness of which shall not in any way be affected or influenced by the various regional air pressures created by the action of the propeller.

In my Patent No. 1,502,062, issued July 22, 1924, I have disclosed and claimed generally a blower suitable for use in connection with a marine boiler room. The present invention constitutes an improvement over that patent,\ particularly in that the propeller and its prime mover are supported from the converging-diverging casing by means including radially extending guide vanes at the down-stream side of the propeller, the guide vanes being curved in kthe direction of `fluid flow. As the inlet end of the Vertical converging-diverging casing is connected to a suitable structure, for example, the'deck of a ship, such casing constitutes a support for the blower, the propeller, and the prime mover; and, as the means for supporting the propeller and its prime mover includes curved guide vanes, a Verylstronfg structure 4results. The guide vanes not only serveito remove the twist or swirl from air discharged from the propeller, but also serve as very strong structural elements Afor supporting the propeller and its connected prime mover. In other words, the guide vanes are very strong in radial directions, thereby making it possible for such vanes to resist radial stresses, both tension and compression, and inaking the supportingstructure lquite resistant to any Vibration or unbalanced stresses that might be set up in operation.

In addition, I so form 'the guide vanes that their entrant portions are inclined at a gradually increasing pitch in a direction toward the blower axis so as to conform with the generally provided increaseA in inclination of the propeller bladefrom its tip to its hub portions. In this way, the entire entrance edge of each guide vane receives the air discharged by the propeller with little or no change in its direction, thereby avoiding serious edge and shock losses.

I also arrange the guide vanes so that they do not extend radially from the blower axis but the leading and trailing edges are set forwardly or rearwardly of radial lines, whereby greater stiifness is obtained, air flow noises are reduced to a minimum and the formation of pockets in the air flow passage is avoided, all as will be pointed out more fully hereafter.

The present invention further resides in providing a blower of the vertical type which is adapted to be entirely suppbrted from an overhead structure, such as the deck of a ship, and

of the entire prime mover from the underside of the blower without disturbing the yblower casing, guide vanes, foundation structure, etc., in any way.

Apparatus made in accordance with my invention is illustrated in the accompanying drawings,

forming a part of this application, in which:

Fig. 1 is a vertical, sectional view of one form of blower apparatus arranged in accordance with my invention;

Fig. 2 is a plan view, showing the form of stationary guide vanes employed in the blower shown in Fig. l;

Fig. 3 is a diagrammatic view showing the formation of one of the stationary guide vanes illustrated in Figs. 1 and 2;

Fig. 4 is a detail plan view of the upper bearing of the blower shown in Fig. l; and

Fig. 5 is a view in section taken' on the line V-V of Fig. 4. p

Referring now to the drawings more in detail, I show a blower of the vertical type including a vertically disposed converging-diverging casing 10 having its upper end secured by bolts 11 to a converging intake duct 12 forming a portion of the ship structure and depending from the deck f' 13. An `opening 14 is provided in the deck 13 for the entry of air. It is obvious that, instead of the arrangement illustrated, the blower casing 10 may be made to include the intake duct 12 in which case the blower casing 10 is directly connected to the deck structure of the ship. A propeller 15y is` located intermediately of the height of the lcasing 10 and it is driven by a vwhich will permit the removal and reinsertion suitable prime mover, 'at 16. The propeller 15 and its connected prime mover are supported from the blower casing 10 in a manner to be hereinafter described.

The casing 10 preferably consists of a converging portion `17, an intermediate substantially cylindrical portion 18, and a diverging portion 19. The propeller is preferably disposed in the intermediate portion 18.

The blades of the propeller 15 extend radially and have their inner ends secured in place with A 57 adapted to be rigidly secured, as by bolts 57',

"respect to an upwardly converging conoidal member or hub portion 21 having secured thereto, as by suitable bolts 21', a cap or shtail 22 extending above the propeller and into the converging portion of the casing.

In the form of propeller which I prefer to employ, the axial pitch of each blade increases from the leading to the trailing edge, while radially the pitch of each blade is constant, all as shown and described in U. S. Patent No. 1,596,459 issued April 17, 1926 to me for a Propeller pump and assigned to the Westinghouse Elec. & Mfg. Co.

Referring now to the means for driving the propeller, I show a vertical drive shaft 23 having'its upper end secured to the conoidal hub portion 21 of the propeller by a nut 23 and its lower end secured to the rotor element of the prime mover 16, the latter preferably taking the form of an impulse steam turbine including a blade disc 24 secured to the shaft 23 and having blades 25 carried bythe periphery thereof.

The bladeA disc 24 is arranged in" a casing 26,

the latter being provided with a steam inlet 27 and an exhaust passage 28. A 4nozzle box 29 is arranged in the casing 26 with nozzle passages 30 disposed for thdischarge of high velocity steam laterally of the blades 25. In order to secure a multi-velocity impulse effect, a reversing chamber 31 may be arranged on the opposite side of the blades 25 from the nozzles 30.

Referring now to the means for controlling the passage of steam through thejnlet passage 27,` I show an oil pressureresponsive governor apparatuS, atv 40, which includes a casing 4l and a piston 42, the position ofthe piston 42 inthe casing being dependent upon the pressure of liquid supplied through the inlet passage 43 in a manner well known in the art. The piston 42 is provided with a stem 44 connected to the throttle valve 45 in the steam inlet passage 27.

Oil under pressure varying as a function of the speed of the turbine rotor and of the propeller is supplied by a centrifugal oil impeller 46 formed as a thrust bearing collar secured to the lower end of the vertical shaft 23 and resting upon thrust bearing shoes 47, the collar 46 being formed with a central, or eye portion 48, which receives oil from the inlet passage 49 and discharges it through radial passages 50 to the pressure chamber 51.

Referring now to the means for supporting the propeller 15 and the prime mover 16, I show a central core structure 56. The central core structure 56 is provided at its lower end with a ange to the turbine casing 26. Near the upper end of the central core structure 56, there is prov ided a flange 58 for supporting a bearing 59, the bearing 59 being arranged to retain the drive shaft 23 in vertical alignment. The lower side of the turbine casing 26 is secured, as by bolts 60, to a bearing housing 61. The bearing housing 61 provides a radial bearing 62 for the lower end of the shaft 23 and. in addition. houses the thrust bearing structure already referred to. The entire weight of the propeller 15, the drive shaft 2 3, the turbine blade disc 24, etc., is transmitted to the bearing housing 61 through the thrust bearing shoes 47. It is therefore apparent that the central core structure 56, the turbine housing 26 and the bearing housing 61 are all joined together so as to form a single structural orprime mover element, which I have designated by the reference character 63 and which includes the shaft 23 as well as the turbine blade disc 24. The structuralor prime mover element 63 is adapted to be removed as a single unit from the blower casing as will hereinafter be described.

Provided within the blower casing 10 at the discharge side of the propeller 15 are a plurality of fixed guide vanes 66 rigidly secured to the blower casing l0, as by welding. Secured to the inner ends of the guide vanes 66, also preferably by welding, is a blower casing annulus 67 having an upper cylindrical portion 68 and a lower diverging portion 69, the two portions being secured together preferably by welding. In this connection, I wish to point out that I prefer to secure all parts of the blower casing together by welding, suitable welds being provided at 69 between the converging, cylindrical and diverging portions of the blower casing. In this way, the casing annulus 67, the stationary guide vanes 66 and the blower casing l0 are all formed into a single, unitary. autogenous structure, which structure possesses extraordinary rigidity and which structure is especially well adapted for use with blowers of the type herein disclosed wherein the entire prime mover element as well as the propeller are supported directly and entirely fromthe blower casing and not by extraneousfoundation structure.

Secured to the lower end of the casing annulus 67, as by welding, is a flange ring 70 to which the entire prime mover element 63 is secured as by bolts 71. From inspection of Fig. 1, it will be apparent that my arrangement of the blower is such as to permit the ready yremoval and replacement of the entire prime mover element. This can be readily accomplished by first removing the bolts 21', the fish-tail 22 and nut 23', whereupon thel propeller 15 may be freed from the drive shaft 23 and the entire prime mover element, that is, the drive shaft 23, the turbine 16, the bearing housing 61 and the central core structure 56 including the bearing 59 lowered to the deck below. I preferably provide a tapped hole 72 in the upper end of the drive shaft 23 for securing to the drive shaft a suitable sling. In the process of lowering, the sling passes through the lbore of the propeller hub 21 as well as the casing annulus 67. It will therefore be apparent that my arrangement of blower is such that the entire prime mover element may be removed and replaced without disturbing in any way the blower casing structure or without disturbing in any way the attachment of the blower casing to the deck structure. Access may be had to the upper end of the blower casing either -by means of a man-hole 78 or by suitable access means provided above the deck 13 in the blower inlet 14.

Referring now to the specic structure of the a stationary guide vanes 66, reference may be had to Fig. 2 wherein it will be noted that the guide vanes 66 are curved, rather than fiat, in the direction of air flow, the direction of rotation of the propeller being indicated by the arrow shown in Fig. 2. Forming the guide vanes in this way, not only results in more effectively removing the swirl from the air stream discharged by the propeller but, in addition, materially strengthens the entire blower casing structure laterally so that torsional vibration of the prime mover element is held to a minimum.

As stated heretofore, I prefer to employ a propeller of the type wherein the pitch of the blades tion near the tip portion than near the hub portion. I therefore form the entrant portions of each guide vane so as to comply with the direction of the air stream formed on the discharge side of the propeller and, in Fig. 3, 73 represents a cross section of one of the stationary guide vanes 66 near its tip portion while '74 represents the curvature of the vane at its hub portion. rIhe axis of rotation of the propeller is graphically indicated by the line 'I5 while the plane of rotation of the propeller is indicated graphically by the line 76. From inspection of this figure,

it will be apparent that the angle a, which is the angle made by the hub end of the entrant portion of a guide vane with respect to the plane of rotation of the blower is less than the correspending angle that is, the angle made by the tip end of the entrant portion of the same guide vane with respect to the plane of rotation of the blower. In other words, each guide vane 66 is so formed that its entrant portion is inclined at an increasing angle with respect to the plane of rotation from the hub portion to the tip portion. In this way, the guide vanes more accurately comply with the form of air stream created by he propeller and they therefore receive the air almost tangentially throughout their entire length and consequently proceed to remove the twist or swirl created by the propeller without offering any appreciable resistance to air ow and with little or no absorption of the kinetic energy of the air stream. While I have, in th'e foregoing description, referred to a propeller having constant pitch radially but increasing pitch axially, nevertheless it is obvious that my principle of forming the guide vanes so as to comply with the formiof air stream created by the propeller is also applicable to forms of propellers having materially different design characteristics than those set forth in the present embodiment.

In arranging or locating the guide vanes 66 in the blower casing, I prefer to so locate the guide vanes that the entrant edges are not located on radial lines, but, on the other hand, are set ahead of radial lines. 'Referring to Fig. 2, 77 indicates graphically a radial line while '78, the entrant portion of each guide vane, is located a ldistance, indicated by ahead of the radial line 81, the direction of rotation of the propeller 15 being such as indicated by the arrow. At the same timeas is apparent from Fig. 2, I prefer to locate the discharge edge 79 of each vane some distance to the rear of the radial line '17. I have found that such an arrangement possesses among others the following three important advantages:

1. Greater rigidityin that the well known ad- 4vantages of the cross'spoked wheel effect are obtained.

2. `Air ow noises are materially reduced in that the entrant edges'of the guide vanes are not disposed in parallel relationship with the air streams thrown off by each propeller blade and hence, instead of the air stream thrown off by a blade meeting the entrant edges of the guide vanes throughout their entire lengths at one instant, the air stream successively meets the entrant edge of each guide vane from its hub to its tip portion so that, what I have termed, a shear or scissors effect is obtained and, in this way,

asfound from actual test, air flow noises are materially lessened.

3. Arranging the stationary guide vanes with a portion of the guide vane ahead of the radial line and 'another portion behind the radial line avoids the formation of undesirable pockets where the guide vanes 66 join the casing annular 67 so that the resistance of the air flow passage, that is, the passage intervening between the blower casing 10 and the casing annulus 67 is materially lessened.

Referring now to the method of lubricating and governing my improved form of blower apparatus, reference is again made to Fig. 1 and particularly to the pressure chamber 51 to which oil is supplied under pressure by the oil impeller 46. The pressure chamber 51 is connected by means of a conduit 8l to the inlet 43 of the oil governor. The conduit 81 is also provided with a branch 82 for supplying lubricant through pas- 1 sages 83 and. 84 to an oil inlet 85 provided in the bearing 59. An orifice 86, or any other suitable pressure reducing means, may be located in the conduit 82 so as to lower the pressure of the lubricant passing to the bearing 59 below that supplied to the governor 40.

All the lubricant supplied to the bearing drains from the lower end thereof and is deflected from the drive shaft 23 by a suitable deector 89 and deposited in the lower portion of the central core structure 56 in an annular collection chamber 91 formed by an inner sleeve 92 and the casing of the central core structure. Lubricant passing to the upper end of the bearing 59 is trapped by an annular groove 93 and conveyed by radial holes 94 to the exterior portion of the bearing. As shown in Figs. 4 and 5, the bearing 59 is provided With three annular shoulders 95 connected by circumferentially spaced bosses 96 through which suitable bolts 97 extend for rigidly securing the bearing 59 to the flange 58 of the central core structure 56. Interposed between the bosses 96 are a plurality of circumferentially spaced .openings 98 through which openings lubricant -ing 59 a deflecting member 99 provided with suitable packing such as felt 100. I also provide suitable openings 101 and 102 in both the turbine casing 26 and in the central core structure 56 so that the discharge air pressure of the blower prevails in the annular space intervening between the central core structure 56 and the blower casing annulus 67. In the operation of blowers of the forced draft type, it has been found that the pressure prevailing in the immediate vicinity of the discharge end of the propeller, that is, in the drawn into the opening 14 by the propeller vicinity -of the deflecting member 99, is relatively low in comparison with the pressure prevailing at the discharge end of the blower casing and may be said to be a minus pressure. There is there'- fore a tendency for the propeller blower to. suck or pump oil from the adjacent bearing into the' air stream and, in order to avoid this, I not only provide `the deflecting member 99 and packing 100 but I so arrange the openings 101 and 102 that the full discharge pressure of the blower is irnposed upon the upper end of the bearing 59, whereby any leakage toward the propeller from the bearing is air leakage and not lubricant leakage. It .will be noted that the air low passage between the central core structure 56 and the blower casing annulus 67 is quite substantial so that therefis always an abundant supply of air at discharge pressure in the vicinity of theA bearing 59, which supply is many times capable of compensating for any leakage through the packing 100. The full discharge air pressure of the blower is also'conveyed to the underside of the rearing 59, it being transmitted through the annular clearance between the inner sleeve member 92 and the drive shaft 23-and thence through the annular clearance provided between the inner sleeve 92 and the deflector 89. In addition, both lateral faces of the bearing V59 communicate directly with each other through the several openings 98 in the bearing so that the full discharge pressure of the air prevails upon both sides of the bearing 59 and the lubricant may consequently drain freely from the bearing entirely unaffected by the air stream created by the propeller. I have found that blowers so constructed may be operated for several months time without any escape of lubricant whatsoever from the bearing into the air stream, this being apparent from the fact that upon dismantling, the packing 100 has been found to be dry.

Lubricant accumulating in the collection chamber 91 is conveyed by means of a conduit 103 to a suitable lubricant reservoir 104. The lubricant reservoir is supported entirely upon .the prime mover element 63 and is removable as a unit therewith. '1"he lubricant reservoir 104 is preferf ably located near the lower end of the drive shaft 23 but at sufficient height to provide a positive head of lubricant upon the inlet eye of the impeller 46. Lubricant discharged from thegovernor apparatus 40 is returned by means of a conduit 105 to the reservoir 104.

From the foregoing, the operation of my improved form of blower will be apparent.

15 and discharged through the stationary guide vanes 60 to the fire room'in a manner well understood in the art. The blower casing 10 is preferably ar ranged so as to have a divergent portion whereby the energy transmitted to the air by the propeller in the cylindrical portion of the blower lmay be transformed into casing and which is in the form of velocity energy, pressure energy by the divergence of the casing.

Governing of the prime mover element is obtained by means of the oil impeller 46 which is directly connected to the drive shaft 23 and which therefore develops a pressure which varies as the square of the speed of the drive shaft. This pressure is conveyed by means of the conduit 8l to the governing mechanism 40 for controlling the .supply of motive steam to the turbine in a manner well understood in the art. Lubrication of the lower bearing 62 is readily effected in that this bearing communicates directly with the pressure Air is` chamber 51 while lubricant is conveyed to the upper bearing 59 through the conduit 82 and passageways 83, 84 and 85. All lubricant discharged from the bearings is returned to the reservoir 104 and recirculated by the impeller 46.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications, without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is:

1. In a blower, the combination ofa casing, aV

rotary member disposed within the casing for effecting a forced circulation of air therethrough, a stationary annulus member disposed on the dis'- charge side of the rotary member, a. shaft for driving the rotary member, extending through theannulus member, a bearing for the shaft disposed within the annulus member, means for supplying lubricant to the bearing, means for removing lubricant drainage from the bearing, a structure extending within the annulus member for supporting the bearing, said bearing supporting structure being spaced from the annulus member so as to provide an intervening passage of substantial ow area, packing means associatedfwith the end of the annulus member which is located adjacent to the rotary member for sealing the shaft, and communicating means provided between the exterior of the casing and the vspace intervening between the bearing supporting structure' and the annulus member, whereby pressure of air is maintained within the annulus member and leakage of fluid from the annulus member toward the rotary member is confined to nation of a casing, a propeller disposed in the throat portion of the casing, inner and outer core members arranged coaxially of the casing and disposed adjacent tothe propeller, guide vanes connected to the casing and to the outer core member for supporting the latter from the former, means for operatively connecting the inner and outer core members to maintain the inner c ore member in position coaxial with the outer core member, .a power shaft extending through the inner core member. and connected to the propeller, a bearing for the shaft and arranged near to the endof the inner core member adjacent to the propeller, a passage formed between the core members and in open communication with the region at the discharge end of the casing, and passages for affording communication between the first passage and opposite ends of said bearing.

3. In fluid translating apparatus', the combination of a vertically-disposed casing having a throat portion, a propeller disposed at the throat portion ofthe casing, a central core structure arranged coaxially of the casing and located adjacent to the propeller, guide vanes connected to the casing and to the core structure and supporting the latter from the former, aA power shaft extending through the core structure and connected to the propeller, a bearing for the shaft provided at the inner end of the core structure adjacent to the propeller, a turbine including a rotor connected to said shaft and a housing structure supported by the core structure, a step bearing for the end of said shaft removed from the propeller and including a collar carried by the shaft and bearing means carried by the turbine housing structure and cooperating with saidcollar, and a centrifugal pump including as the impeller thereof said thrust bearing collar for supplying lubricant to said shaft bearing.

4. In a vertical blower, the combination of a vertically disposed casing having a throat portion, a propeller arranged within the casing at the throat portion thereof, a core structure disposed coaxially Vof the casing and located at the discharge side of the propeller, guide vanes connected to the casing and to the core structure for supporting the latter from the former, a power shaft extending through the core structure and connected to the propeller, a turbine including a rotor carried by the power shaft `and a housing structure connected to said core structure, means for supplying motive uid to the turbine including a pressure-responsive controlling valve, a step bearing for supporting said power shaft and the elements carried thereby and including a collar provided at the lower end of the power shaft and cooperating with bearing through the inner core member and connected to the propeller, a bearingl for the shaft and arranged near to the end of the inner core member adjacent to the propeller, a passageformed between the core members and in open communication with the region at the discharge end of the casing, and vpassages for aording communication between the rst passage and opposite ends of said bearing. 4

HENRY F. SCHMIDT.

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