US2459166A - Main feed pump recirculating line erosion control device - Google Patents

Description

L. E. HUGHES MAIN FEED PUMP RECIRCULATING LINE EROSION CONTROL DEVICE Jan. 18, 1949.

2 Sheets-Sheet l Filed DeC. 20, 1944 `2,459,166 ING 2 vSheets-Sheet 2 L. E. HUGHES Jan. 18, 1949.

MAIN FEED PUMP RECIRGULAT y LINE ERosIoN CONTROL DEVICE Filed Dec. 20, 1944 rwQ/YIKW- LElGHTON Ef HUGHES Il l|| Hl lll FIG .-3

Patented Jan. 18, 1949 MAIN FEED PUMP RECIRCULATING LINE EROSION CONTROL DEVICE Leighton E. Hughes, United States Navy Application December 20, 1944, Serial No. 569,074

(Cl. 13S-37) (Granted under the'act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 3 Claims.

This invention relates to erosion control in conduits in which a high velocity water jet is directed, and more especially to means for dissipating the energy of a jet employed in the recirculating conduit of a high pressure water pump to prevent damage to the conduit.

In steam plants, whether ashore or afloat, it is customary continuously to feed water at high temperatures and pressures to the boiler. In the conduit between the pump and the boiler, there is provided a control valve which may manually be operated if the level of the water in the boiler rises too high to shut off the ow of feed water. While there is usually a governor for controlling the speed of the feed pump, and hence, the volume of water it discharges, before this becomes effective, the churning action of the pump upon the water which is already approximately 250 F., will raise the temperature of the water to such an extent as to cause the pump to become vapor bound. For this reason there is provided a bleeder or return conduit from the discharge side of the pump for returning the water, when the discharge of the pump is stopped by closing the A conduit of aforesaid valve, to the condenser. very small diameter will take care of the volume of water to be returned at the high pressure employed, approximately 750 pounds per square inch, but for practical reasons, a conduit of much larger diameter actually is employed so that it will not easily be broken. When a large conduit is employed, however, an orifice of small diameter must be included therein to reduce the volume of water iiowing through the conduit, and it is the damage caused by this high velocity jet with which the present invention is concerned.

Considerable difficulty is experienced when a high velocity jet of water is discharged in a conduit due to the fact that small particles of abrasive material in the water are thrown with great force by the jet against the walls of the conduit which causes erosion of the conduit, hence, it is an object of the present invention to provide means for dissipating the energy of the jet after it has passed through the orice, so that its velocity will be comparatively low, which may readily be installed in existing equipment with a minimum of change therein and which is susceptible of replacement when it becomes Worn out, at a low cost. y

In its broadest aspect, invention resides in means for dissipating the energy of a high velocity jet passing through an orifice, the aforesaid means comprising a member having a substantially spherical recess therein open toward the jet Cil 2 and adapted to receive the impact thereof and to turn it back upon itself so that in counterow it is in contact with the surface of the forwardly moving jet.

As illustrated herein, the invention resides in disposing between the pump discharge and the return conduit, a fitting having an orifice at the end adjacent to the pump discharge through which `water under high pressure flows, thereby to produce a jet, and a member disposed in the conduit in a position to receive the impact of the jet having aprecess therein, the walls of which are reentrant, and are adapted to change the direction of iiow of the jet to lcause it to double back upon itself and hence to create counterflow along the jet, and also to intersect the incoming jet, thereby t-o retard its forward movement. As shown herein, the aforesaid recessed member is removably mounted in the fitting and when worn out may be replaced without diiiiculty and without uncoupling the fitting.

Itis another object of the invention to provide a method for dissipating the energy in a high velocity jet.

In this aspect invention resides in intercepting the high velocity jet, turning its direction of flow back upon itself sothat it intersects the forwardly moving jet and causing it to flow rearwardly while confined in part along the surface of the forwardly moving jet.

The invention will now be described with reference to the accompanying drawings, in which:

Fig. 1 shows a section through the fitting which includes my invention;

Fig. 2 is a diagrammatic illustration of the method in which the jet is caused to flow backwardly upon itself thereby to dissipate its energy; and

Fig. 3 shows a modification of the fitting embodying my invention.

In steam power plants, the boiler is supplied vwith feed water at high temperatures and high pressures by a feed Water pump. In the steam power plant of the type with which the present invention is concerned, a two-stage centrifugal pump is employed for feeding water at high temperature and high pressure to the boiler. Between this pump and the boiler, there is provided a manually operable valve which is normally open to permit substantially continuous feed of water to the boiler but which may be closed by an operator if the level in the boiler rises too high. If this valve is closed, however, the centrifugal pump will churn the Water so violently that the temperature will rise to the point where the pump hence, to reduce the erosionl in theY rv reason a pipe of suicient diameter' is provided' so that it will withstand ordinary shocks. If', how;- ever, a large conduit is used, anforice'mustlbe provided to reduce the volume of water flowingthrough the same, and for this' reason"y there" is" placed in this conduit adjacent to the discharge side of the feed pump, an orice for controlling the volume of water passing through the pipe; Since the pressure of the water passingthr'o'ugli the orifice is high, a jet'- is formed which is very destructiveA and1 soon erodes the return' conduit `so that it must be replaced; It is the' purpose-:of this invention to provide meansv fori-dissipatirrg the energy of this jet to render it harmless, and urn feed conduit.

Referring to- Fig. 1f, the fitting' is: designated generally by the' reference' character I`0" and provided with a flange: |2by which' itisf attached tothe flange |6' of thendischargeside ofY a high pressure-water pump; YBetweenithe flanges` IZ'and i6 there is disposed'l a-plat'e' |'4 having; an orifice |56` therein adapted' toco'nstrictthe flow ofhig-h pressure water: from the. pump and to i regulate f its volume.. To make the connection between the ange. andA thev plate l 4 watertight; a pair of washers 2li are disposed on opposite-sides of the'y plate between the fianges'l-Z and'- |6l.` Theltting I6 consistsof ahollowv cylindrical bod'y12Z having. a branch-conduit 24 leadingl from" one side. thereof substantially midway between-l itsends, the branch 24 having xedtheretoa ange 26which is adapted 'to' be clamped to' theendl of-v av con'- duit (not shown) for returning the feed? water'to 'thecondensen The end of the cylindrical body 22,' adjacentt'o theoric'efis reduced' at l 28 and? its opposite endl isfturnedl down to for-m1 a shoulder 30.. @ver'the'v turneddowni end. portion there is telescopicallytted'asle'evef32 which: sitsv against .l the shoulder 36 and is fastened theie'tol ini-'any suitable manner. as by welding.' Theisleeve232 is of somewhat larger diai'net'erv than the inside 'diameter' of. the'body' 22V and isi-adaptedl vti) removably receive a block 35i. thoinner end of' which Y is providedvvith-l a shoulder' 38I whichiabuts `the peripheral end 4m of the'bo'd'y' 22,.. The. block: 36 'has formedtherein an recess 42TY which?. opensi'in'to the hollow cylindrical body 22 and has a spherical bottom and'. sides, thefsidesid.beingfreentrant. The block 36 is held in plac'eiwithin'th'elsleeVf32 by a. threaded plug 48 which 'has a nut shaped head 50 tol which v a tool. may7 be' appliedfffor; in'h sorting or removingthe same. To preventaccifdental removal. of the plug 48, a staple is formed on the sidef of .the sleeve 32.r through which there is passed' a..wire=54;lthef wirein `turn being, threaded` through: arperforatiorre formed intheperiphery of' the head 50.y

A modified form ofzthe tti'ngz is: shown.y in". Fig. 3, indicated generally-'by tl'ieneference character `513-. In this` form of therinvention,thellttin'g 58 is provided with a1flange-60by which.: theriitting is attachedto the angef 62=xof the: discharge? side of a high. pressure' pumpandz as inithef previous case,, a platey 64' having: an orice 6611 therein-i is the oriiice, is turned down to provide va shoulder 'I2 and telescopically ttedover this turned down endifslafsleevef'. Into the sleeve 14'there is inserted a block 16 having the recess 18 formed therein: which1 is open to the inside of the cylindrical body 68`, the recess having a spherical bottom-8W and? sides-821 the sides 82 being reentrant. The-block 16 is retained in place by a threaded plug 84 which is screwed into the end of the sleeve T4, the"A plug beingA provided with a nut shaped head "36zy adapted to receive a tool for removing or replacing the plug. lin this form of the invention, the cylindrical# bcdy'ef enclosed' 'inra iholvlow"-cylli'ndi'icalhousing-Sill of larger diameter'than the bcd'y''; oneP endl offwhi'cnisfclosed by a wall inl-*welded thereto, whicl'r` isI apertured'. to receive the bodyff andi is-.adjacent to the reduced porrtion thereof. The cylindrical: body 68 has aiplural'ity orepeningsaa formedtnerein adjacentto lthelerid walieg through whichthewaterwill flow trom the body 68 into an annular spacey 93;v betwee'ifrA the c'ylindricalilbodyf Biand'. the; cylindrical housing '96; Thef open yend of' the cylindrical housing 9c terminates'-near the! head. 816fcfir the plug?. anfdifhas ffastened'th'ereto a flange y'941 by vwfiicl'iithe fitting isfasten'edto a flange 961 oi'ia. coupling, 918g. the: couplingin'. turn havingV a; flange Atill)"whereby itmay befastened to the' end: of: the conduit'fm returning thefeedwaterto thezconzdenser;A

.Tnl'opera-tion; thehighapressure water' (750 pcundsipersquarezinch) whichzis also-at a rather higit temperature, 25.0 discharges from the feedzwater pump through the? orifice off the/fitting, aridin dissi-patingthe energy of theI jet, ity is desirable? toprevent. damage tos the return conduitl As illustrated :inV the ltwoy forms of the -finventiorrgthe jetJ isi-nterceptedby thespherical .surface-44- or` 8i) of-tl1ie bl'ocle36 or 16; Tofillus.- trate-theaction-.f'which takesr place,. there is? shown in=-Fig. 2, aV purely diagrammatic view of the 'course ofthe jet from the time it leaves/the orillce until its energy is dissipated and'it iiowsl at -g-zreatly reducedf. velocity to the.- return conductor. The: jet-'which isy designatedr by' the reference character J, FignZ, passes# through the orifice fwallss arefreentrant ini character, the.rearwardly moving Water is' causedl to flow across, that: is,

y intersectfthe forwardly Amovingfjet as it y leaves -tlre `freces-s atsaboutthefpoint M, and totravel "rearwardly between the: surfacex ot the.' incoming -jet and-ther walls off the,- cyliiiolricall body. This 'rearwardly flowing liquidE has considerablyT less -velocity'than the incoming jet andl its intersecitionf withfthe jet. tendsf tofretard. the-r oncoming jet thereby dissipating part of its energy. -More oven', the; rearwardly flowing` streamis constantly retarded." by contact withthe walls of; thef fitting *anditliis retarded.streamlinv turn by surfacev corrtactwith therjetaretards its flow,. setting; upa :turbulence-between them.- asA indicated: by the arrows t. When the rearwardly owing stream reaches the branch 24 or the openings 88, it will flow' into the return conduit and back to the condenser.

The invention described herein may be manufactered and used by or for the Government of the United States of America for governmental purposes Without the payment of any royalties thereon or therefor.

What is claimed is:

1. In a conduit in which there is an orice through which passes a jet of fluid under high pressure, means for dissipating the energy of the jet, comprising a member having a substantially spherical recess therein opened toward and symmetricaliy disposed With respect to the axis of the jet, the reentrant Walls of Which extend through an arc of substantially more than 180 to reverse the iioW of fluid to cause it to intersect the oncoming jet in a substantially opposite direction, thereby to retard its flow.

2. In a tting for a recirculating system comprising a length of conduit having an orifice near one end through which fluid under high pressure flows in a high velocity jet, said conduit being of larger inside diameter beyond the orifice, and a member having a substantially spherical recess therein with reentrant Walls extending through an arc of substantially more than 180 disposed in the enlarged portion of the conduit in a position symmetrically disposed with respect to the axis of the jet and to receive the imp-act of the jet and to reverse the direction of the deilected water to intersect said incoming jet in a substantially opposite direction, said member being composed of hardened steel and being removably mounted therein.

3. A tting for a recirculating system comprising a length of conduit having an orice near one end through Which fluid under high pressure passes in a high velocity jet, a member having a substantially spherical recess therein With reentrant Walls extending through an arc of substantially more than said recess being symmetrically disposed with respect to the axis of the jet and arranged in the conduit to cause a reverse flow of the fluid to intercept the incoming jet in a substantially opposite direction, said conduit having a plurality of openings therein near the orice end thereof, and having telescopically surrounding the conduit, in axial alignment therewith, a second conduit adapted to receive the flow of iiuid from said openings and conduct it in the direction of the jet along the outside of the rst conduit.

LEIGI-IION E. HUGHES.

REFERENCES CITED The following references are of record in the rile of this patent:

UNITED STATES PATENTS Number Name Date 1,942,598 I-IeWgley Jan. 9, 1934 1,968,716 Smith July 31, 1934 2,380,839 Hand July 31, 1945 FOREIGN PATENTS Number Country Date 332,785 Italy Dec. 9, 1935

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