US 2772834 A
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Description (OCR text may contain errors)
Dec- 4, 1956 P. F. swENsoN ETAL 2,772,834
STEAM TURBINE OPERATED CENTRIFUGAL PUMP MECHANISMS Filed` Oct. 22, 1952 3 Sheets-Sheet I5 E mm MNM 7 as n ESP. .r VN.v mwow/ c f 5. f En MM Pm Y B United States Patent O STEAM TURBINE OPERATED CENTRIFUGAL PUMP MECHANISMS Paul F. Swenson, Cleveland Heights, and Myron T. Cooperrider, East Cleveland, Ohio, assignors, by mesne assignments, of thirty-seven percent to Otto Wanek, two percent to Kenneth J. Kitchen, ten percent to Paul F. Swenson, ten percent to Marcus 0. Swenson, four percent to Myron T. Cooperrider, eleven percent to Wilma G. Stupka, eleven percent to Wilma G. Stupka, trustee, ten percent to J. A. Weeks, and five percent to Earl P. Schneider, trustee Application October 22, 1952, Serial No. 316,212
11 Claims. (Cl. 237-67) The invention relates to a new or improved, steam driven pump mechanism, particularly for use in connection with a steam heater system for returning condensate from heater units to a steam generator. In domestic and other steam heating systems it is desirable to employ a closed fluid circuit in order to conserve water and heat; and, in installations such that the condensate cannot be returned to the generator by gravity, a pump of some kind has to be used. Steam and electrically driven pump mechanisms are available for the indicated purpose but usually at relatively high cost. The electrically driven pumps require a power source extraneous to that of the heater system. An object of the present invention is to provide a simple and inexpensive automatically and eiciently operating, condensate pump mechanism which does not require an extraneous power source.
Other objects will become apparent from the following description of a preferred form shown in the drawings wherein:
Fig. 1 is a schematic view showing a closed .fluid circuit type steam heater system and one manner of connection of the subject pump mechanism or unit therein (unit size exaggerated with respect yto other elements of the system).
Fig. 2 is a plan View of the pump unit in three quarter scale (covers removed).
Fig. 3 is a sectional view taken along the line 3--3 on Fig. V2.
In Fig. 1, A represents steam generator or boiler having a steam line A connected to supply a plurality of heaters or radiators, one indicated at B, having a condensate return line C. Line `C is connected to the subject pumping unit D, the main body 1 of which is an unsealed, i. e. freely air-vented tank. A steam line E connected with the generator supplies a steam turbine assembly F of unit D through a valve mechanism G which is operated cyclically in response to changes in liquid depth or quant-ity in the tank, as by a float H. The oat is connected to the valve by a snap-action or toggle mechanism l which elfects rapid valve movement to on and off positions a1:` maximum and minimum liquid levels respectively. The condensate pump (impeller K) connected to the turbine `receives condensate from a iilter chamber R, hasa pump chamberV L provided with an outlet duct forcondensate, a helicalLchamber-providing portion M of which duct is in heat exchange relationship toa turbine exhaust steam condensing space or chamber N, which latter is in open liquid ow enabling communication at O with the main liquid content space of the tank. The pump outle'tjduct portion M is conventionally connected, as by line.P,1to the steam generator A. Y
If the heater B of Fig. 1 is made according to Patent No;V 2,692,759 granted' October 26, 1954, to'Marcus O. Swenson and Paul F. Swenson, then the condensate in line'C` will have its maximum temperature limited, by an ice emergency control shown in that application, so as to be' well below the average boiling point of water (actually to around 170 degrees F.) whereby the temperature of all the water in tank 1 is 'adequately low to enable itsuse as a condensinguid medium for the exhaust steam of turbine F. If no provision is made in heater B to limit maximum heating medium` return temperature then it assumed that some other temperature limiting means would be used. Normally the tank 1 is located far enough from the heaters to insure an adequately low liquid temperature in the tank for turbine exhaust steam condensing purposes. The subject pump, for reasons which will become evident, is .however able to'return the condensate back to the boiler even though the condensate, as received from the heater units, is at the boiling point, i. e. too high a temperature to insure condensation of turbine exhaust steam wholly within the unit D;
Referring to Figs. 2 and 3, the tank body 1, as shown, is made as a simple rectangular sheet metal vessel flanged inwardly as at 2 around its open top for support of the turbine and pump assembly F, L etc., and suitable cover sections 3 and 4 (Fig. 3 only); Cover` section 3 closes only the tank portion in which the iloat H and connected snap action steam valve mechanisms l and G are disposed. Section 4 forms a top wall for a turbine impeller housing having a central cup-like portion depending into the tank and containing an impeller wheel 6 co-operating with steam nozzle 7 in the manner shown at the upper right in Fig. 2. The turbine, as shown, is generally the same as one more fully described in the Swenson et al. application. Y
Turbine housing member 5, as shown, is formed from sheet metal as a shallow, generally rectangular, pan
with a top rim or flange 8 extending over the tanlc side walls and one end wall as best shown in Fig'. 2. Portion 8 of the flange supports a tting 9 which Vforms the body of the steam valve G. Fitting 9 supports the lloat- H. Flange portion 8 has an opening 10 into which the condensate line C from the heater or heaters extends loosely. The opposite side 8 of the' flange 8 carries a ttng 11 to which pump outlet line P is connected.
The bottom wall of turbine housing member 5, at a self-aligning bearing assembly 12, described later, carries the turbine output shaft 14, and the lower end of the shaft is radially supported by a similar self-aligning bearing assembly 15 mounted on a cylindrical stil upright tube 16 depending from the turbine housing member 5 and detachably secured to it as by screws. Tube 16 is the principal part of pump chamber L around and in radially spaced relation to the shaft. The bearing assemblies and their supports act as uid blocking or sealing closures for the upper and lower ends of the tube 16 thus defining therewith the generally closed pump chamber L. The lower shaft support and closure assembly 15, see Fig. 3, includes a generally rectangular filter supporting stamping 18 the top wall of which slopes downwardly in all `directions from its region of attachment to the tube 16. A laminated lter body 20, preferably largely of spun glass, is supported by a one piece sheet metal frame 21 having substantially identical side-forming elements of channel shaped cross section whose flanges embrace the lter body Vmargins and downwardly stepped continuous ange vportions of stamping 18. The filtered-waterchamber R, which is self-emptying of air or gas bubbles, is thus maintained for supplying the pump inlet which, as will be described, is constituted by a hollow lower end portion of shaft 14. Two relatively adjacent side-forming elements of the frame 21 (e. g. at one corner of the frame) are detachably secured together by a suitable clip not shown.
Theself aligning and Huid-sealing featuresof'the bearlv 3 ing assemblie`s`12 and 15 are obtained in part by provision ofcarbon bushings 22 and 25' of identical form, each with a polished bore nicely ttinga respective portion of pump shaft 14 and each having a generally spherical head 24 received in` mating central"pt )lr'tfiio'ns of the' respective 4niembers and 18'. The spheric'zal heads of thef bushings are heldin tight sealing Contact with their mating supporting surfaces by retaining spring metal'rdiscs 26 andZZ engaging respective spherical'heads. Snap rings 22 and 22," around'the shaft 14'abut relatively adjacent ends of the bushing-22' to hold'the shaftvertically in working position; The shaft 14 is preferably. stainless steel and, except for the snap-rin'g-reeeiving grooves in the' shaft, the latter isl of uniform diameter in and below the hub 6' of the turbine impeller.
The pumprotor orY impeller K is a smooth circular metal-*disc 28Y having a-'hub portion 28 for attachment of the disctov the shaft The disc preferably has a single diametral bore which: forms `two substantially radial passages-29 communicatingfat-'their inner endswith an axial bore-30 inthe-bottoml end: ofthe shaft 14; which end'of thshaftis` always immersed in4 liquid contained: in space R- between the lower pump chamber closure and the lter20. Y
lt-jis importantthat the-steam valve control mechanism G,-H, Jl be so designed that, at minimum liquid level of condensatein -the tankythe impeller-of the pump will be below that'level; Assuming such design'and` ample ow capacity vof the-filter, the mechanism, partly due to maintenance of at least-some pump-supply water head; insures boiler waterreplenishmentl whether or not (as'due to too highY temperature condensate return from the heaters) all' the turbine exhaust steam isl condensed in the chamber N.
The smooth axial faces of the impeller disc 28and its smooth circular periphery are spaced considerable distances from thel nearest surrounding walls defining the pump chamber L, so that fluid drawn into the shaft bore 30and` ejected centrifugally by.- theV radial; passagesp2`9 is free toow in any required direction away' fromA the im-` peller. TheV outlet-toy the pumpV chamber (fitting 32., for helical? outlet duct describedl later) is preferably near the topv ofthe pump chamber in order that no substantial volumes of` air or vapor which may be entrained in the water as by operation of thepurhp at veryih'igh' speed 'on high temperature condensate, 'will' be trapped in the pump chamber. Y 'i 'lhel exhaust steam from' the4 turbine chamber passes through. exhaust ports 34 in housing'member Sinto' annular-*condensing chamber` orV space N formedl around and constitutedlinpartl-by the pump chamber wall`1`6` co'- op'erationwith a relatively surrounding sheet meta-1 sleeve 36; The sleeve 36 is suitably sealed at its upper end 'Y around-the external periphery of turbine housing' member 5 by which thesleevefis supportedY in thetank. The lower end-of the-sleeve-S is open, as by being spaced uniformly above the bottom of the tank, b ut said end of the sleeve is continually immersed in water (lower edge of sleeve below minimum water level permitted by cyclical action of the oat controlled mechanism as will be apparent)4 in order to'maintan a water sealfor the chamber'.
Normally to insure condensation'of all theturbine exhaust steam in annular space N the outlet fittingY 32 of the pump chamber has connected therewith the single helical coil of metal tubingv M leading to output fitting 11, thus forming a condensing-medium-chamber having a relatively large effective heat exchange surface within the chamber or space N and concentric therewith for increasingsurface exposure to turbine exhaust steam asits volurne increases or the space for it is enlarged. by lowering ofthegeneral water level in the tank. Thecoil M; moreover, has adequate condensing-.surface area to insure that the exhaust. steam will, remain trapped in chamber, N under negligible pressure so that turbine efficiency' does not tend to be reduced by increase of exhaust steam .pressure and so that no portion ofj the exhaust steam will be 4:. ejected into the vented general tank space around the sleeve 36 and result in loss of water from the heater system.
The effective condensing-Chamber-dening surfaces of the tube 16, of theV surrounding sleeve 36 and of the pump outlet tube M all increase as the Vheight of the steam-trapping water column maintained within the available condensing chamber space N diminishes.
The steam valve chamber provided by tting 9 is normally closed by a poppet type plug 40 to block passage of steam to turbine nozzle 7. Ar stem portion 4l' of the plug slides in a guide bore in the fitting; 9, below which-thestem has a double flange or spool formation 42. A channel shaped bracket 43 is secured rigidly to the lower end'of fitting 9 and the bracket is designed to afford a free pivotal support at 44l for a steam-valve-operating yoke 4 4, made as a stiff metal plate, and, further, to form or provide another differently located free pivot, as at 45 fory a snap action toggle yoke member 45, Shown as Of U-shape as viewed in Fig. 2.V Yoke plate 4'4- loosel-y straddles the spool formation 42 of the valve stem.
Yoke 45` is directly attached toa stiff, float-supporting arm 46; anda pair of-ten`sion`coilfsprings 47A are connected for over-centreto'ggle action between the yoke 45 and valve-actuating plate 44: Vertically' spaced apart lugs 48 on yoke'45, positioned for abutment with a side wing 44 (Fig. 2-)7Y ofthe plate 44, tend-'to insure opening and closing movement of the steam valve (as the oat approaches its high and low water-level-determinedpositions, respectively) in case of `deterioration ofthe springs 4'7' or in case the'valve or its'actuating plate 44'cannot, from any cause, be moved freely by toggle'spring action alone.
The springs 47, for adjustment of their eifective forces, andl in order 'to enable them to` b e made inexpensively and oflong-useful-life, aresecured at their ends by machine screws 49r having rounded under-headsurfaces seated in conical depressions in thescrew-supporting partsv andwith their'l threadedYV Shanks engaging the associated spring` end coils. The coils-effectively lockthescrews, by well-known spring clutc action against turning in the necessary direction to relieve the adjusted tension of the springs, and adequatelyrestrainthe screws from turning in the opposite direction solelybyfriction. g
Referringl further to the operation of the mechanism described above, the steam valve G remains closed' until the accumulation of lcondensate in the tank 1 causes lifting of float H to about its full-lne-illustr'ated position, Fig. 3, whereupon the turbine operates the condensate pump K to supply the generator A until depletion of-condensate in the tank allows the float tofmove to approximately its broken-lne-illustrated position at which the steam is quicklyand 'fully turned off, completing the operating cycle. The-steampressure and the force of the-snap actionmechanism springs hold the valve. G'fully closed. Due to the illustrated turbine design, the light'load. imposed on the turbine'by the relatively smallv circular pump impeller K in itsnon-'conning-.chamber and to the nearlyfriction-free, self-aligning, carbon bearings of the shaft 14, the turbine (supplied with steam at around 6 to 10 p. s. i. as a typical pressure for domestic heating) turns its output shaft assembly at between 5,000 and 7,000 R. P. M. At 10 p. s. i.' steam pressure the pump has been found to deliver about`400pounds of water per hour. The turbine exhaust steam is. fully condensed without breathing loss in chamberA N at a rate such as will allow e'cient turbineactionif the` temperature of condensate, as returned to ,theV unit D', is below lSO'degrees F.
In case, due to faulty (e. g. dirt-restrained) operation of the snap action valve mechanism I, the. steam. valve is not fully opened and the turbine is therefore not supplied'with steam at a high' enough rate to elfect high speed rotation of its impeller, accumulation of steam in theV condensingchamberv space N, by depressingthewater columninthat chamber, tendstoraise-the levelLofwater in` the float-containingor,` main part ofthe-tank, thus aiding the toggle-mechanism in fully and quickly opening the steam valve. Since the heat of the steam used to loperate the turbine is mainly ,returned to the steam generator with the condensate output of the pump the operyating expense of the described mechanism is negligible. Even friction loss is conserved as heat.
I claim: t
l. A condensate pumping mechanism for ,a steam heater system or the like, comprising a tank, a low pressure steam turbine associated with the tank yand having an upright output shaft, a steam supply valve for the turbine, tank-liquid-level or quantity controlledmeans 'to move the valve to on and off positions, a centrifugal pump having an impeller coaxial wi-th said shaft and connected thereto for operation bythe turbine, the pump having an inlet continually immersed in liquid contained by the tank and having an outlet duct, means in the tank forming a condensing chamber for the turbine, means connecting the outlet of the turbine with said condensing chamber at a predetermined level, said chamber having an inlet in communication with the tank and `opening into the chamber at a lowerlevel, a portion of the pump outlet duct being located within the chamber Ebetween said levels for direct exposure to exhaust steam :therein when the condensate is at a predetermined level, :and the outlet duct of the tank being uncommunicated with the interior of the chamber and tank.
2. In combination, an open or vented storage tank for condensate of a steam heater system, steam admission 'valve means operated to on and off positions by low andhigh liquid level in the tank, a steam turbine supplied through said valve means, the turbine having a rotary output shaft extending downwardly into the tank, a condensate pump connected with theshaft and having a condensate inlet continually immersed in liquid in Kthe tank, wall means forming into upright chambers, one of the chambers surrounding the pump and receiving its liquid ,output and the other chamber forming a receptacle for turbine exhaust steam, said receptacle having an opening at its lower end in position for continual immersion in liquid contained by the tank, and the wall means forming at least one of the chambers having a steam-condensing wall surface portion, exposed, during operation of the turbine, to exhaust steam contained in said other chamber, in a manner such Ithat as the depth of condensate in said other chamber decreases, the condensing surface area exposed to exhaust steam increases.
3. In combination, an open or vented storage tank for condensate of a steam heater system, steam admission valve means operated to on and off positions by low and high liquid level or quantity in the tank, a steam turbine supplied through said valve means, the turbine having a rotary output shaft extending downwardly into the tank, a condensate pump connected with the shaft and having a condensate inlet continually immersed in liquid in the tank, wall means forming three chambers, each in surrounding relationship to the shaft axis, and including a first chamber surrounding the pump and receiving its liquid output, a second chamber forming a receptacle for turbine exhaust steam, which receptacle receives such steam at its top end and is open near the bottom of the tank for continual immersion in condensate contained by the tank, and a third chamber forming part of an outlet duct for liquid received by the first chamber to conduct such liquid from `lthe tank, and the third chamber having steam condensing wall surface portions exposed, during operation of the turbine, to exhaust steam contained in the second chamber.
4. In combination, an open or vented tank adapted to store condensate liquid as from a steam heater en route to a steam generator, a steam driven turbine having an output shaft supported for rotation on an upright axis extending toward the bottom of the tank and connected to a centrifugal liquid impeller having an inlet passage in position to be continually immersed in liquid contained `llay the tank, two wall members providing an upright annular condensing chamber connected at itsy upper end to the turbine for reception of turbine exhaust steam, the chamber at or near its lower end being open for discharge of turbine exhaust steam condensate into the tank, one of the Wall members surrounding the other, the inner one of the wall members defining said annular chamber forming an imperforate side wall of a pump chamber around the impeller, and means connected to provide a pump-chamber-discharge duct located in said annular chamber and having a steam-condensing surface portion adapted to be exposed directly to exhaust steam in said chamber in amounts increasing with the increase in volume of uncondensed steam.
5 The arrangement accordingto claim 4, wherein said pump-discharge-duct-forming means is a metal tube connected to an upper end por-tion of the pump chamber and coiled into a helix in the condensing chamber.
6. In combination, an open orvented storage tank for condensate of a steam heater system, steam admission valve means operated to on and off positions by low and high liquid level or quantity in the tank, a steam turbine supplied through said valve means, the turbine having a rotary output shaft extending downwardly into the tank, the shaft having a hollow bottom terminal portion, a circular disc coaxial with, and rotatable with, the shaft and having generally radial passages communicating with the hollow portion to provide a centrifugal pump element for the condensate, wall means forming three chambers, each in surrounding relationship to the shaft axis, and including a first chamber containing said pump element, a second chamber forming a receptacle for turbine exhaust steam, which receptacle, at or near its lower end, is in open communication with condensate in the tank, and a third chamber disposed within the second chamber and forming a helical outlet duct for the pumpcontaining chamber, and wall surfaces defining the third chamber being exposed to exhaust steam during operation of the turbine.
7. In or for a heater system, condensate transfer mech anism comprising a steam-turbine-driven pump including an upright shaft, a tubular approximately cylindrical housing surrounding the shaft with its circumferential wall in radially spaced relation therefrom, closures for the two ends of the housing, iiuid sealing, self-aligning journal bearings for the shaft in respective closures, a steam turbine assembly above the upper closure connected to drive the shaft, a circular pump-forming disc on and concentric with the shaft and located between the closures, said shaft having a downwardly extending axial liquid inlet passage which has its inlet end in communication with the space outside of the housing, said disc having generally radial passages formed therein and communicating with said inlet passage, the perimeter and axial faces of the disc being spaced respectively from the housing wall and said closures sufficient distances so that the liquid ejected from the generally radial passages is substantially unrestricted against free ow in any direction in the housing, and means forming a liquid-discharge passage in a wall of said housing for the output of the pump.
8. An apparatus for a closed circuit system employing a steam generator, a heat exchange apparatus supplied with steam thereby, and a condensate return line; said apparatus comprising a vented condensate reservoir tank adapted for connection to the return line, a steam turbine adapted for connection to receive steam from the generator and having an upright exhaust-steam-condensing chamber within the condensate reception space of the tank, said chamber having a continually open outlet into the tank in a position to be always sealed by condensate in the tank, a condensate pump permanently connected for opera-tion by the turbine and having its inlet'in the tank and its outlet uncommunicated with the interior of the tank and adapted for connection with the generator, a turbine steam supply valve, and operating means for arrastre the valve-arrangedv and connected Vfor Voper-ation of! the valve cyclicallyfrom'- on to ott valving` positions as a functin'of hi'gh and low quantity respectively of condensate intheV tank, whereby the reception space for turbineexhaust steam in'V the condensing-f chamber is automaticaltl-yV enlargedas.' the quantity ot? condensate in the tank is diminished" by progressionl of the cycle` toward: completion;
9.. Ant apparatus'for a steamv` heating system, said' `apparatus comprising an open or vented tank for condensate', a' low pressure steam turbine, a centrifugal condensate pump connected for operation by the turbine, a snap action valve connected to supply steam to the turbine, meansl arranged for operation in accordance with high' and low level or quantity of condensate in the tank, saidv means operating to open and ciose the valve when the level isV high and low, respectively, wall means formingjasteamv condensing chamber in the tank, the top of the-chamberl being-connected to the exhaust side of the turbine ina manner to receive allv the exhaust steam, andV the bottom of the chamber being open and continually immersed in liquid in the tank in all relative positions of the snap action valve and its operating means, means connecting the inlet of the pump to the tank outside of the condensing chamber, and conduit means connected tothe outlet of the pump and leading outside of the tank and having a portion exposed in at least the upper portion of the condensing chamber for contact with exhaust steam in the chamber at predetermined condensate levels therein.
10. In` and for a steam heating system, an open or vented tank for condensate, a steam turbine, a steam valve for admitting steam to the turbine, a oat movably mounted i'n the tank and connected to the valve by snap action. means for moving the valve to full on and full ott positions in accordance with predetermined high and; low levels of liquid in the tank, a condensate pump in the tank connected for operation by the turbine and having a condensate inlet and a condensate outlet duct, means formingy a -condensing chamber in the tank connected at' its top end to the turbine for reception of all of the turbine exhaust steam, the` lower end of'f'thel condensing` chamberbeing` openY below the lowest level of condensate in the tank permitted by the float and' snap action means in their steam-valve-clos'ing relative position, a portion of said' condensate outlet duct occupyingr the condensing chamber in position to provide increasing condensing contact with the turbine exhaust steam as the reception space for such steam inthe chamber increases.
11. In combination, a vented. storage tank for condensate of a steam heater system, a steam turbine adapted to receive a supply of steam and having a rotary output shaft extending downwardly into the tank, a condensation pump connected to the shaft and having a condensate inlet continuously immersed inl liquidi in the tank, wall means forming two'v upright chambers, one of the chambers surrounding Ithe pump andreceiving its liquid output and the other of the chambers surroundingl said one of the chambers and forminga receptaclefor turbine exhaust steam,` said receptacle having an opening: at its lower end and in position for continual immersion in liquid' containedv by the tank, and the wall means for-ming at least one of the chambers having a steam condensating wall portion which, during the operation. of the turbine, is exposed at one face to exhaust steam contained inthe sai'df other chamber in a manner such thaty as the depth of condensate in the said other chamber decreases, said condensating wall portion has an increasing condensating surface area exposed to exhaust steam, and said wall portion being in Contact with the liquid dischargedY by the pump at the other face.
References Cited in the file of this patent UNITEDl STATES PATENTS Re. 18,275 Jennings Dec. 8, 19311 291,271 Baker Jan. 1, 1884 975,526 Hood Nov. 15, 1910 1,342,544 Kohler June 8, 1920 1,634,304 Schleyer July 5, 1927 2,271,353 Spillman Jan. 27, 1942 luf-imig