US1990093A - Exhaust steam injector - Google Patents

Description

Feb. 5, 1935.

E. RAWSON EXHAUST STEAM INJECTOR Filed May 7, 1952 INVENTOR BY 9% he;

ATTORNEY Patented Feb. 5, 1935 I UNITED". STATES PATENTOFFICE EXHA ST STEAM INJECTOR Emanuel Itawson, North'Bergen, N. .I., assignor to The Superheater Company, New York, N. Y.

ApplicationMay 'z',"1 932, Serial No. 609,858 9 Claims. 01.103-265) The present invention relatesto exhaust steam be understood-that. the present invention is not injectors and has particular reference tojexhaust limited in its application to this specific type of steam injectors for supplying feed water to 1000- exhaust steam injector. It may be applied to motive boilers. Still more particularlythe invenother types of exhaust steam injectors as well.

55 tion relates to exhaust steam injectors of the A common characteristic of exhaust steam intype adapted to be operated whollyby live steam jectors of the type disclosed in the aforemenwhen exhaust steam is not available. t d patent a d in similar types s the supp y In the employment of exhaust steam injectors to'the-injector, in addition to water, of high presfor supplying feed waterto locomotive boilers, sure'live'steam, hereafter referred to assupple 10 numerous widely varying conditions of locomotive mentarysteam, and further, exhaust steam from 10 operation must be taken into consideration if the the engine or when exhaust steam is not availinjector is to operate satisfactorily, that is, is to able, low pressure live steam. -The'low pressure be able, to supply feed water to the boiler at all live steam will hereafter be referred to as auxiltimes, regardless of momentary locomotive oper- 'iary steam.

l5. ating conditions.' In order to provide for con :In the injector arrangement illustrated, extinuous injector operation under the conditions haust steam is admitted to the injecto B through existing inlocomotive operation, numerous conthe conduit 10 leading from the ngine exhaust trol systems have beenheretofore proposed but P pe (not shown). Water is supplied to the inthe systems heretofore proposed have uniformly jector through conduit 11 and the boiler feed wabeen based upon the utilization of steam admitted ter is delivered under pressure from the injector to the engine cylinders or exhaust steam from through the delivery conduit 12 which is connectthe locomotive engine as the means for actuating ed to the usualboiler check valve (not shown). the control system. The injector overflow pipe is indicated at 13. l

In accordance with the present invention I pro- Steam for operating the injector is taken from 2o pose to dispense t either exhaust or m t m the boiler turret indicated at 14 and is conducted as the means for controlling operation of i the t0 theinjector u h h p sur Steam injector and instead employ electrical means res pply p pe 15 in W ch, is located the manually sponsive to the speed of operation of the locomo- Operable ma n l v lve 1 Ordinarily situtive engine for governing the injector control tilled nq e engine system. By this means I obtain numerous advan- Pipe 15 is divided at the injec or into two 30 tages as compared with prior controlisystems branches 16 and Branch 16 pp upwhich will be more fully pointed out inconnecp l v S am a high pressure toa suittion with the ensuing description of a suitable able no e in e i j c and h. p-

iorm of apparatus for carrying the invention into p i r au y v steam to t j r a W effect. pressure to take the place of exhaust steam when 35 In the drawing accompanying this specification he la er s not ava able. and forming a part hereof: The admission of aux'liary livesteam to the in- Fig. 1 is a diagrammatic elevation of the me, jector-is controlled through the medium of an A box end or a locomotive boiler showing an injec aut mati or h v r va v i di at d ntor arrangement embodying thepresent invenorally at C. this Valve operating to either p 40 tion installedthereon; or close the-branch 1 7. The use of automatic or Fig. 21s a section on an enlarged scale of a pa t changeover valves in control systems of the charof the apparatus shown in Fig. 1; e aeter n. question is known p Se a d injectors Fig. 3 is an elevation on an enlarged scale of of he Character described ordinarilyinclude 8X- 40 part ofthe apparatus shown in Fig. 1; and v haust-steam controlvalves which operate in con- Fig. 4 is a'. similar view of another part of the junction with the automatic or changeover valves apparatus shown in Fig. 1. so that either'exhauststeam or auxiliary live Turning now to the drawing, the fire box end of steam is supplied to the injector. the locomotive boiler and the cab of the locomo- Theeen ral nstr t a d p ati n of aptive are indicated in dash lines A and the injecparatus of this type forms per so no part of the 50 tor is indicated generally at B. present invention and need not be described in de- The injector indicated is of the general type tail. disclosed in'United States Patent No. 1,531,004 For reasons which will appear hereinafter I granted March 24, 1925' on the application of Malprefer to employ an automatic or changeover colm Hard and WiIliamBuckbee, although it isto valve of the type disclosed in the copendingap- 5.5

bore in the casing 18. A chamber 22 is formed in the casing above the valve 21 and a, spring 23 may advantageously be employed to seat valve 21 against its lower valve seat. Above chamber 22 a second chamber 24 is provided in which is located a piston 25.

27. High pressure live steam is admitted through passage 28 to the space above piston 25, and through a suitable clearance space 29 and channel 30 to chamber 22, when the relay 26 is in its upper position as shown in the figure. Chamber 24 is placed in communication with the live steam supply admitted through passage 28, by means of a suitable port which may be in the piston as indicated at 31. g I

When the relay valve 26 is seated against its lower seat, communication is established between the chanel 30 and an atmospheric vent- 32.

Chamber 22- is providedwith a connection 33 leading to suitable means for actuating the valve controlling the admission of exhaust steam to the injector. I

Chamber-24 is provided with a vent pipe 34 leading to atmosphere or, as indicated in Fig.1, a zone of low pressure within the injector. A valve 35 is located in vent pipe 34 for controlling steam flow therethrough.

The operation of the changeover valve is as follows:

Assuming valve 35 to be closed as shown in Fig. 2 and the main control valve 16 to be open, high pressure live steam enters chamber 24 by way of passage 28 and port 31, causing piston to lift the relay valve 26 to the position shown in the figure. With the relay valve in this position, high pressure steam passes through clearance space 29 and channel 30 to chamber 22 and holds the changeover valve 21 against its lower seat, thus closing the branch 17 and preventing the admissionof auxiliary live steam to the injector. High pressure live steam from chamber 22passes through the connection 33 to open the exhaust steam valve so as to admit exhaust steam to'the injector. v If valve is open, chamber 24 is vented through pipe 34 and the release of pressure from this chamber forces piston 25 down so as toseat relay valve 26 against its lowerseat. This closes communication between channel 30 and the pas sage 28 through which high pressure operating steam is admitted to-the valve and' establ'ishes communication between channel'30 and the at mospheric vent 32. Consequently, pressure in chamber 22 is released to atmosphere and valve 21 is lifted' from its seat by unbalanced steam pressure in chamber 19. At the same time the release of pressure inchamber 22 permits the exhaust steam valve to close due to release of pressure in connection 33.

As soon as steam starts to flow through branch 17 after valve 21 is lifted, the pressure of this steam is automatically reduced due'to the throttlingjactionof the choke port 20.. f

open position-by spring 39 acting on will be evident from Fig. 2 valve 35 when the solenoid coil 38 is energized and will open when the coil is de-energized.

Piston 25 is connected to a double. seated relay valve 26 located in a' third chamber valve 35, and to this end the valve head 35' of valve 35 is connected by means of a suitable stem 36 to the core 37 of a solenoid the coil of which is indicated at 38. The valve head 35 is moved to stem 36. As will be closed For the purpose of controlling energization of the solenoid coil '38 I provide electric current generating means such as a generator indicated at 40 in Fig. 1. Generator 40 is operated at a speed varying in accordance with the speed of operation of the locomotive engine and may advantageously be driven by means of a belt 41 from one of the axles 42 of the locomotive.

Preferably, generator 40 is of the type generating current'the voltage or amperage of which varies in accordance with variations in speed of the generator. One terminal of the generator is connected to the solenoid coil 38 by means of the connection 43 and the other terminal of the generator is connected to the solenoid coil by means of connections 44 and 45; Electricalconnection between connections '44 and 45 is controlled bymeans of a device indicative of steam admission to the locomotive engine. Preferably, some part of the throttle control mechanism for the main engine is employed for this purpose and a suitable arrangement has-been indicated in Figs. 1and3. In accordance with the'arrangement shown, the usual pivoted throttle lever 46, having connected thereto the throttle'operating rod47, is provided with a spring contact 48 insulated by suitable strip of insulating material 48' and having-connected thereto the connection. 44. The quadrant 49 has attached thereto ametal contact strip 50 against which the spring contact 48 is adapted to bear. The strip 50 is advantageouslyinsulated from the quadrant-49 by means of the strip of insulating material 51. Contact strip 50 has connected thereto the connection 45, and the portion of the strip at and adjacent to the position of lever 47 corresponding to closed throttle is covered by a-strip of insulating material 52, the position of which on thecontact strip 50. may be altered by-means ofthe adjusting screw 53; 1 With the above described arrangement it will be seen that the generator 40and the solenoid coil' 38 are connected in an electric circuit which will be broken when the throttle lever 47 is in closed position or in a position adjacent thereto and which will be completed when the throttle lever is moved to a position admitting steam in predetermined quantitiesto the engine. It will further be evident that when the engine is standing: still or is operating below a predetermined speed-the solenoid coil 38 will not be energized even if the engine-throttle is open and contact is made at contact 48, due to the fact that with the engine'standing still or moving at a speed below a predetermined rate the generator 40- will not produce current of sufficient strengthto ener- :1

gize coil 38 and close valve 35 again'st thepres sure of spring 39.: It follows therefore that-with the arrangement illustrated. thesolenoid valve 38 will be energized so as to cause the auxiliary steam supply to be shutioff fromth'e injector only after a certain'speed of operation of the engine has been obtained and also :only after the engine throttle has been opened byv a predetermined amount. With thecontrol circuit'operating; in response to these two factors, assurance is *had that the auxiliary steam'supply .willbe cut oil and exhaust steam admitted to the injector only under operating conditions which-ensure aproper exhaust steam supply. By way of illustration let us consider conditions when: the locomotive is drifting. Under these conditions the speed responsive generator may be producing current, of sufficient strength to energize the solenoidicoil, butwhen the engine is drifting. the throttle :must be adjacent closed position, in Whichevent-the control circuit is broken dueto the factthat the contact 48 is onthesinsulating istrip 552 Under drifting conditions-not enough steam is supplied to the engine to provide suflicient. exhauststeam for. injector. operation-and as explained above, under these; conditions the control circuit'is =bro,- ken at the throttle and auxiliarysteam is admitted to the injector. :5 r .r r r :1 r

Undersome conditions trainsare held station? ary on grades by admitting justzsufficient steam to the engine toprevent backward movement of the, '..locomotive. Under such R conditions the throttle may be openedsuhiciently toclose the control circuit, but, due to vthejlack of. movement of the; locomotive nocurrent is available .in the circuit for energizingthesolenoid. Under the above conditions there is obviouslyrno exhaust steam. available .for .'njector,;operation ,1 even though the engine ,throttleis open: and under these conditions thegcontrol system.pr.ovides for the admission of auxiliary live steam-to operate the injector,

Witha control system according tolthepresent invention, numerous advantages\ are obtainable. In systems heretofore employed whereengine steam chest pressure is employed: to govern the position of the changeover valve, the ;above-de-.- scribed condition of operation, in which s eam is admitted to the engine without producing ex haust steam available for injector operation, leads to serious operating difficultieswhichcan only be corrected by theaddition of more or less com: plex auxiliary controlmeans; In systems where,- in exhaust steam pressure is employed as an actuating medium for the changeover valve di-fliculties are encountered due, to pulsations or variations in exhaust steam pressure which are diiiicult to eliminate with practical equipment andwithout undue complication. -Unless such pulsations are effectively eliminated or neutralized, the. control equipment operated by exhaust steam pressure ;is subject to chattering operation whenthe exhaust steam pressure is atorabout the correct'pressure for causing changeover of the injector from exhaust steam operation to live steam operation or vice versa.

By the present arrangement all-pi. the difiicul ties heretofore encountered I are eliminated; The control equipment is extremely simple, all piping for conducting operating steam ,fromtthe engine steam chests .is eliminated as is alsoall' piping for conducting exhaust steam to a diaphragm or other. valve tozbe operated thereby. Further more,- the'entire .control equipment-maybe built as a unit at the injector because of the fact that no means, such as long. pipes; needs to be-used to provide the so-called timingchambers'hereto fore found necessary in exhaustisteam operated control systems, timing chambers beingresorted to inprevious systems in order to eliminate as 7 far as possible: the chattering operation due to pressure pulsations in the exhauststeamsupply. -..Ordinarily;in the operation of locomotives the pOSitiOnr of the reverse lever for the main engine, which also serves toregulate the amount of valve cut-off of the engine, is indicative of engine speed, 'a long cut-off beingemployed at slow speeds under heavy load and the cut-off being shortened'as the speed increases.- This provides an additional means whereby. acontrol circuit in accordance with the present invention may. be further r'governed;v .As shown'in Fig. 4, the reverse lever 54' is provided with a contact 55 insulatedfrom the lever by the strip 56 and the quadrant57 is provided with acontact strip 58 insulated fromthe quadrant by strip 59. An insulating strip 60 providesfor breaking contact between parts 55 and 58 when the reverse lever is in mid position or adjacent thereto.

It is'possible to employ thereverse lever instead of 'the throttle lever as the means indicative of steam admission :to the engine but. the throttle lever arrangementIis-tobe preferred. If therefactor controlling verse. lever is employed as a the electriczcircuit, I prefer'to connect the contacts governed by this lever in. series with the contacts-governed by the throttle lever so that operation of the injector on-exhaust steam can be-efiected only if the throttle leverand thereverse lever are bothin correct positions for admitting steam to the engine... Ordinarily the engine throttle willne'verlbe opened sufiiciently to make contact in thecircuitunless the reverse lever is in aposition such that thev'alve gear will admit a suitable quantity of steam to the engine butit is possible fortheengine throttle tobe openedq-and. for steam tobe substantially shut off from the engine because of the fact that the engine. valve gear is in neutral position or in a position giving an-extremelyshort cut-off. The possibility of shifting the injector to. exhaust steam operation under the above'unusual circumstances may be effectively guarded against byiproviding circuit .contacts at boththe throttle mechanism and the reverse levermechanism.

. It will be apparent'from the foregoing description that many variations in the arrangement shown by way of illustration may occur to those skilledcin the. art without departing from the scope of the invention. Thus for example a type of changeover valve other than that'illustrated may be. employed. For example, a valve .of the type. disclosed in United States Patent No. 1,574,798 granted to Hans Deutsch on March 2, 1926, may be employed. However, it is preferable to'use a valve of the type illustrated since it has-sheen. found that through themedium of a relay valve "the size of the solenoid and consequently of the-generator necessary toeiiect the desired control, may be very materially reduced. It will alsobe' evident that generators of various different types may be employed, but a generator producing electrical energy the value of which varies with thetspeed of operation of the generator is to be preferred because of the. relative simplicity as compared with other electrical'arrangements'involvingcircuit closing'and opening means which are speed responsive.

For. purposes of 1 the present invention the electric circuit comprisingthe solenoid is tobe considered as being energized only when zit is energized to the degree necessary to efiectactuation of the valve operated by the: solenoid. .:It will be apparent that if a generator: is .zplaced directly in the circuit, some current-'willflow through the circuit-,provided the circuit. is closed, atengine speeds below that speedxat 'whichithe change-over valve should be shifted'to the position cutting 01? the auxiliarysteam supply, but until the amount of energy developed in the.cir= cuit reaches a value sufficient to efiect actuation of the solenoid operated valve, the circuit'is to be considered as de-energized.

While for purposes of illustration the iriven= tion has been shown as applied to an injector delivering water'at high pressure to a locomotive boiler, and consequently requiring a .supplylof supplementary high pressure steam, the *inven--' tion is not limited to thisctype ofxinjector but may be employed equally wellin conjunction with injectors operating with lower delivery pressures and not requiring high pressure steam.

What is claimed is:

1. Apparatus of the character described comprising mechanism for governing steam admission to an engine, an exhaust steamlinjeotor adapted to operate on steam exhausted from said engine and a control system for said injector comprising a changeover valve foradmitting aux iliary live steam to the injector andmeanstconi-i prising an electric circuit for governing actuation of said changeover valve, said circuit includ ing means responsive .to variationsin. engine speed for energizing thecirc'uit when the engine speed reaches a predetenninedvalue and means associated with said. mechanism for opening the circuit when said mechanism is adjustedior steam admission to the engine at a rate below a predetermined value, said changeover valve being closed when said circuit is energizedeand being opened when the circuit is de-energized.

2. Apparatus of the character desribedcomprising throttle mechanismfor governing steam admission to an engine, an exhaust steam in jectcr adapted to operate on exhaust steam from said engine and a control system for, said in jector comprising a changeover valvefor admit ting auxiliary live steamto the injectorand electrical means for governing operation of said changeover valve comprising anelectric circuit including a generator adapted itQ, energize'the circuit when the speed of the engine reaches a predetermined value and contacts adapted to open the circuit when the throttle'mechanism is in closed position.

3. Apparatus of the character. described comprising throttle mechanism for governing steam admission to an engine, an exhaust steam injector adapted to operate on exhaust steam from said engine and a control system for said injector comprising a changeover valve for admitting auxiliary live steam to the injector, a'solenoidoperated valve for effecting closure of the. change over valve upon energization of the-so1enoid,=and means for energizing and de-energizing said solenoid comprising an electric circuit including a generator operable at a speed varying with vairiations in engine speed and contacts operable to break the circuit upon movementof said throt tle mechanism to closed position.

4. In an exhaust steam injectorxof =the type adapted to operate on exhaust steamzirom' an engine equipped with a throttle mechan sm controlling the steam flow to the engine, a control system comprising a -fiuid .pressurenoperatd changeoverrvalvefoi' admitting live steam to the injector, a. fluidgpressure operated relay valve for governin'gthe position of said changeover valve, saidrelay 'having'a'vent and being movable upon closure'of said .vent' to aposition causing closure of the changeovervalvaan electric solenoidoperated valvefor closing said vent upon a predeterminedxdegree of energizationof the solenoid, a. generator operable at speed varying with the engine speed for energizing said solenoid, and means associatedwith the throttle mechanism toprevent' the energization of thesolenoid unless the-throttle is open at least to a predetermined extent.

T 5. In-an exhauststeam injector of the type adapted .tooperate on exhaust steam from an engine equipped with a throttle mechanism controllingv the .steamlflow to the engine and with a cutofii. mechanism determining the point of cut-off, a control system comprising a fluid pressure operated changeoveruvalve for admitting live steam to" the injector, a fluid pressure operated relay valve for governing the position ofsaid changeovervalve, said relay having a 'vent and being movable vupon closure of said vent to a position causing closure of the changeover valve, an electricsolenoid-operated valve for closing said vent upon a predetermined degree or" energization of the solenoid, a generator operable at speed varying with the engine speed for energlzin'gsaid solenoid, means. associated with the throttlem'echanism to prevent the energi'zation ofthesolenoid unless the throttle is open at least toa predetermined extent, and means associated wlth the cut-ofl mechanism to prevent the energization "of the solenoid :below a predetermined length of cut-off.

6. In an exhaust steam injector of'the type adapted to' operate-on exhaust steam from an englne, a control system'c'omprising a changeover valveiror admitting auxiliary live steam to the injector, electrically energized means for causin'g said valve to beclosed and means responsive to variations inthe speed of the engine and to variations in admissionof steam to the engine for actuating said'electrical1y energized means to cause said valve to be closed' only when the speed of the engine exceeds a predetermined value and steam-is admitted to the engine in excess of a predetermined rate.

' 7. In an exhaust steam injector of the type adapted to o 'aerate on exhaust steam from an engine, a control system comprising a changeover valve for admittingauxiliary live steam to the injector, means for governing actuation of said valve comprising anelectric circuit adapted to be-energ ize'dto causesaid valve to be closed, andmea'n's'associated with said circuit for causing it to be energized only when the speed of the engine exceeds-a predetermined value and steam is admittedto the-engine in excess of a predeternii'n'ed rate.

3 That improvement in the operation of a control system for exhaust steam injectors having a changeover valve for admitting auxiliary live steam to the injector which comprises generating an electric current having chara'cteristics var mg in -accor'clance with variations in the speed or the engine from which exhaust steam issupplied to the injector and utilizing the variations incsaidcharacterlstics to efie'ct'closure of the changeover valve only when the engine exceeds apr'edetermi'ned speed and'steam is admitted to the v:engine :at a,- ra'te in excess 'of a predetermined value.

9. In an exhaust steam injector of the type second position causing said valve to close, said adapted to operate on exhaust steam from an encircuit including means responsive to variations gine, a control system comprising a changeover in admission of steam to said engine and means valve for admitting auxiliary live steam to the responsive to variations in engine speed for proinjector and means for governing the actuation ducing and maintaining said second condition of said valve comprising an electric circuit havonly when steam admission to the engine and ing an electrical characteristic alterable from a speed of the engine exceed predetermined values. first condition causing said valve to open to a EMANUEL RAWSON.

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