US2032427A - Exhaust steam injector - Google Patents

Description

March 3, 1936. R. e. MAKELY EXHAUST STEAM INJECTOR Filed May 7, 1952 ATTORN EY Patented Mar. 3, 1936 UNITED STATES EXHAUST STEAM INJECTOR Ralph G. Makely, West New Brighton, N. Y., as-

signor to The Superheater Company, New

York, N. Y.

Application May "I, 1932, Serial No. 609,934

16 Claims.

The present invention relates to exhaust steam injectors and has particular reference to that type of exhaust steam injector which is intended primarily for use on locomotives and which is adapted to be operated by live steam when exhaust steam from the engine of the locomotive is not available.

The invention is primarily concerned with the control system for the injector and has for a gen- 10 eral object the provision of an improved control system operating to insure more dependable continuous operation of the injector under the varying conditions incident to locomotive operation than has been possible heretofore with previous- 15 ly known types of control systems.

Exhaust steam injectors of the type in question must operate dependably under widely varying operating conditions, particularly with respect to the factor of steam supply to the injector. One

20 of the primary advantages of exhaust steam injectors is the fuel saving efiected by reason oi the employment of exhaust steam as an injector operating medium and consequently it is desirable to have the injector operate on exhaust steam for as large a proportion of the total time of operation as possible. However, due to the relatively low pressure of the exhaust steam as compared with the delivery pressure of the injector and further due to the comparatively wide 30 variations in both the momentary and average pressures of the exhaust steam as delivered by the engine, the operation of an injector when operating on exhaust steam is not as stable, nor

d is its range of operation as great, as when the injector is operated wholly by live steam. There are consequently numerous conditions of operation under which the injector will not operate effectively as an exhaust steam injector even though exhaust steam is available, but will op erate as a live steam injector.

The most desirable type of control system for such injectors is therefore one which will cause the injector to be operated by exhaust steam under all conditions permitting satisfactory exhaust. steam operation and which will also cause reliable change over from exhaust steam operation to live steam operation to be effected automatically whenever operating conditions are such that dependable operation on exhaust steam cannot be continued even though exhaust steam is available.

In accordance with the present invention, the types of control systems heretofore employed,

H which systems have utilized either engine steam pressure or pressure of the exhaust steam to;

operating an automatic change-over valve, are improved upon by the employment of electrically operated control means as will hereinafter more fully appear.

For a better understanding of the more de- 5 tailed nature of the invention, the more specific objects thereof and the advantages to be derived from its use, reference may be had to the following description of one suitable form of apparatus for carrying the invention into efiect which is illustrated in the accompanying drawing forming a part of this specification.

In the drawing:

Fig. 1 is a diagrammatic elevation of an injector and control system embodying the invention as installed on a locomotive;

Fig. 2 is a diagrammatic elevation on an enlarged scale of a part of the apparatus shown in Fig. 1;

Fig. 3 is a cross-section on enlarged scale of another part of the apparatus and Fig. 4 is a view partly in elevation and partly in section of a portion of the injector shown in Fig. 1.

Turning now to Fig. 1, the outline of the fire box end of a locomotive boiler is indicated by dash lines designated by reference character A and the injector, suitably mounted on the locomotive is indicated generally at B. The injector shown by way of illustration is of the general type disclosed in United States Patent No. 1,531,004 granted March 24, 1925 on the application of Malcolm Hard and William Buckbee, although it is to be understood that the present invention is not limited in its application to injectors of this specific type of construction.

Exhaust steam from the locomotive engine is supplied to the injector through the conduit Ill and live steam for operating the injector is supplied through conduit ll leading from the 4.0 boiler turret l2 and having interposed therein the main control valve l3.

Water is supplied to the injector through the conduit l4 and the amount of water is controlled by operation of the manually operable control lever indicated at l5. The delivery conduit from the injector is indicated at l6 and leads to the usual boiler check valve (not shown). The overflow pipe from the injector is indicated at H.

The live steam supply conduit H is provided with two branches l8 and I9, the branch l8 serving to supply high pressure live steam, hereinafter referred to as supplementary steam, to the injector at all times when the injector is in opera- QQ and the branch l9 serving to supply to the injector live steam at reduced pressure, hereinafter referred to as auxiliary steam, when exhaust steam is not available. Interposed in branch l3 there is located an automatic or change-over valve 29 which serves to control the flow of auxiliary steam to the injector. This valve may be of any known type but is preferably of the type disclosed in the application of Malcolm Hard, Serial.

' medium of an electrically controlled valve indicated generally at 22 in Fig. 1. In Fig. 3 a suitable type. of valve is illustrated comprising a valve member 23 having a stem 24 to which is secured the core 25 of a solenoid, the coil of which is indicated at 26. A spring 2'! tends to lift valve 23 from its seat and'the valve is seated by the solenoid when. the coil 26 thereof is energized so as to draw the core 25 downwardly against the action of spring 21.

In accordance with the present invention control of the valve 22 and consequently of the opera- .tion of the injector as a live steam injector or as an exhaust steam injector is effected through the medium of the breaking or closing of an electric circuit of which the solenoid coil 25 forms a part. In the embodiment illustrated the opening or closing of the electric circuit is made responsive to two factors indicative of injector operating conditions but it is to be understood that control of the injector need not be necessarily made responsive to-both of these factors but may be made 1 responsive to only one.

The circuit shown comprises a suitable source of electric energy such as generator 28, one terminal of which is connected by wire 29 to one terminal of the solenoid coil 25. It will be evident that a storage battery may be employed instead of a generator. 7 The other terminal of generator 28 is connected by wire 33 to a terminal 3| on a pressure gauge 32 the face of which carries a contact plate 33 connected with terminal 32 by a suitable connection indicated at 34. The indicating needle 35 is connected as indicated at 35 to a second gauge terminal 31 to which is connected wire 38.

Gauge 32 may be of any suitable known form of pressure gauge and the needle 35 moves in response to variations in the pressure of the steam in conduit l0 to which the gauge is connected by means of pipe 33. The connectionbetween gauge 32 and the exhaust conduit 10 preferably contains a small orifice or choke indicated at in Fig. 2.

In addition to the control for the electric circuit provided by gauge 32 a second control for this circuit is provided by means responsive to the presence or absence of overflow from the injector. This means is indicated more or less diagrammatically in Fig. 4. Referring to this figure, 4| indicates the overflow valve of the injector past which water overflowing from. the injector flows through passage 42 tothe overflow conduit IT. A pivotally mounted bucket 43 is arranged so that .when the injector overflows the bucket will be filled and depressed against the action of a spring actuated plunger 44 in contact with the bucket arm 45. Bucket 43 is provided with an opening 43 in the bottom thereof to permit the bucket to drain after the injector ceases to overflow. Passage 42 is enlarged adjacent the bucket as shown so that flow through this passage is not obstructed by the bucket to an extent preventing the normal overflow from the injector required to enable a jet to be established.

A contact 41 is located in the injector casing in a position to be contacted by the bucket arm 45 when the bucket is empty and in the position shown in the figure. Wire 38 is suitably connected to bucket arm 45 and a wire connects contact 47 With the terminal of coil 26 not connected to wire 29. The contact 's? is insulated from the bucket 43 in any suitable manner so that electric connection between wires 33 and 48 is established only when the bucket arm 45 is in contact with the contact 41. 7

From the foregoing description it will be evident that coil 26 will be energized and valve 22 closed only when the gauge needle 35 is in contact with contact plate 33 and when the bucket arm 45 is in contact; with contact 47. Movement of the gauge needle out of contact with the plate 33 will break the circuit and cause valve 22 to be opened by spring 2'1 regardless of the position of the bucket 43 and likewise breaking of the circuit at contact 4? due to filling of bucket 43 by the overflow from the injector will cause valve 22 to be opened by spring 21 regardless of the position of the gauge needle 35.

From the foregoing description the operation of the control system will be more or less evident. .The injector will invariably start as a live steam injector. Upon opening of the main control valve i3 supplementary live steam is admitted through branch i8 and combines with water admitted through conduit l4 to establish a jet. Before a jet can be established, however, there is a certain amount of overflow or spill from the injector through valve 4| which fills bucket 43 and breaks the electrical circuit at contact 41. This prevents energization of the solenoid coil, valve 22 is therefore open and, the change-over valve is consequently open due to the venting of the control pipe 2|. Auxiliary live steam is admitted to the injector through branch l3 and the jet within the injector is established by live steam alone, regardless of the presence or absence of exhaust steam at the time of commencement of injector operation. In this connection it will be understood that the exhaust steam conduit I3 is controlled by the usual exhaust valve which is closed when the change-over valve 20 is opened to admit steam through branch I9.

As soon as the jet is. established and the injector commences operation, the. overflow ceases and bucket 43 drains through the orifice 46. As soon as this occurs, electrical connection is established between wires 38 and 4B and the operation of the injector as a live steam or as an exhaust steam injector becomes dependent upon the presence or absence of exhaust steam at suitable pressure in conduit ID. If the engine throttle is closed or if the engine is drifting with the throttle opened insufficiently to provide an adequate supply of exhaust steam, the pressure in gauge 32 will be insuflicient to force the gauge needle 35 into contact with plate 33 and coil 26 of the solenoid will remainde-energized. The injector will consequently continue to operate as a live steam injector. When exhaust steamat suitable pressure for injector operation becomes available due to opening of the throttle, contact is made between needle 35 and plate 33 and the solenoid coil is iii energized to close valve. 22. Closing of the vent pipe 2| by valve 22 causes the change-over valve 26 to be shifted to closed position, cutting off the supply of auxiliary live steam and admitting exhaust steam to the injector.

Numerous advantages are obtainable with the above described control system which are not obtainable with systems of the type heretofore employed. Among these advantages the following may be mentioned. By the use of an electrical control system, operation of the injector can be governed in response to exhaust steam pressure without having to employ diaphragms or other pressure responsive means of large area which have heretofore been required in order to obtain the necessary actuating force from the exhaust steam, which is utilized at relatively low pressures. Furthermore, with the gauge and choke arrangement employed, it is possible to more effectively diminish or eliminate the effect of the momentary pressure variations characteristic of the exhaust of a locomotive engine. It has been found difiicult in practice where an exhaust pressure operated diaphragm is employed to govern the position of the change-over valve of the injector, to prevent chattering of the valve due to the effect of momentary pressure pulsations on the diaphragm when the average pressure has been at substantially the pressure designed to eifect change in operation of the injector either from live steam operation to exhaust steam operation or vice versa.

By the employment of electrical control an important operating characteristic is obtained without complication of the control system which cannot otherwise be obtained without the addition of a separate control mechanism. It will be evident from Fig. 2 that the circuit controlling the valve 22 will be broken not only when the exhaust steam pressure is insufficient to force the needle 35 on to the plate 33 but will also be broken if the exhaust steam pressure rises to a value high enough to force the needle past the contact plate. This arrangement thus provides for operation of the injector on exhaust steam only within a well defined range of exhaust steam pressures. It is a well known fact that exhaust steam injectors of the character in question be come unstable in operation when the exhaust steam pressure exceeds a certain value, particularly when the injector is operating at partial capacity, that is, with a restricted amount of water admitted to the injector. With the present form of control system breaking of the injector when it is operating on exhaust steam, due to excessive exhaust steam pressure, may be effectively prevented by causing shifting of the injector to live steam operation when the exhaust steam pressure becomes excessive. With the ar rangement provided by the present invention, it will be evident that in case the injector is shifted to live steam operation due to excessive exhaust steam pressure, exhaust steam. operation will automatically be re-established when the exhaust steam pressure returns to a normal value.

As hereinbefore mentioned, many of the factors affecting injector operation vary widely under the service conditions met with in locomotive service and with the best control arrangements now known conditions occur from time to time which cause failure of the injector to operate properly on exhaust steam when such operation is normally to be expected. Furthermore, defects within the injector itself, such, for example, as a badly worn combining or delivery nozzle may cause the injector to fail'to operate properly on exhaust steam when operation on exhaust steam is normally to be expected. Due to the greater stability of the injector when operating on live steam, the injector may be able to operate. successfully on live steam under conditions making exhaust steam operation impossible. With the electric control provided by the present invention, this factor of operation is taken care of very simply by making the electrical circuit controlling operation of the change-over valve responsive to overflow conditions. If, when the injector is operating on exhaust steam, failure of operation occurs for any reason other than normal changeover to live steam operation the resulting spill or over-flow from the injector immediately breaks the control circuit and causes the injector to shift to live steam operation. If the condition causing failure of normal exhaust steam operation is only temporary, as is often the case, the injector will be shifted back to exhaust steam operation as soon as contact is re-established upon the cessation of overflow after the injector commences operation on live steam. If the cause of failure of normal operation as an exhaust steam injector is of a more or less permanent nature, the continued failure of the injector to operate on exhaust steam and the continual shifting over to live steam operation will apprize the operator of the fact that adjustment or repair of the apparatus is required.

Ordinarily, exhaust steam injectors are installed on locomotives in positions where it is difficult, if not impossible, for the operator to see the injector. control system provided by the present invention, it is possible, without undue complication, to provide means whereby the operator may be readily informed of the manner in which the injector is operating. As will be evident from Fig. 1, the pressure gauge controlling the electric circuit may be placed in the engine cab and in order to inform the operator as to operating conditions,

signal means may be readily employed in the' cab for indicating when the control circuit is opened or closed, regardless of whether or not the control circuit is opened or closed by the gauge. Advantageously a signal lamp 49 may be placed in the circuit adjacent to the gauge although it will be apparent that an audible signal may be substituted. With a signal device of this character in the circuit the operator is immediately apprised of whether the injector is op erating as a live steam injector or as an exhaust steam injector. the signal lamp as is always lighted when the injector operates as an exhaust steam injector. If the lamp goes out, it indicates that the injector is not operating as an exhaust steam injector and if the gauge needle is on the contact plate of the gauge it is evident that the injector is spilling at the overflow and that for some reason which should be investigated, the injector is failing to operate as an exhaust steam injector when exhaust steam conditions are such that it should operate satisfactorily on exhaust steam.

It will be apparent to those skilled in the art that many variations in the arrangement shown may be made within the scope of the invention.

The change-over valve need not be of the specific 7 type disclosed in the application of Malcolm Hard previously referred to but may, for example, be of the type disclosed in U. S. Patent No. 1,574,798, granted March 2nd, 1926, to Hans Deutsch. The type of valve shown in the Hard Because of the character of the In the arrangement illustrated,

application is, however, to be preferred since with this type of valve, due to the use of a relay valve, a smaller solenoid may be employed than would be necessary if a valve of the type disclosed by Deutsch were employed. In connection with the use of a solenoid operated valve for governing the position of the change-over valve by controlling the flow of steam through a pressure con duit, it is desirable to place the solenoid operated valve at some distance from the change-over valve so that the conduit connecting the two valves may form what is in effect a timing chamber which causes a lag in operation of the changeover valve with respect to operation of the solenoid operated valve. This lag serves to prevent chattering operation in case any exhaust steam pressure pulsations reach the gauge needle when the exhaust steam pressure is at approximately the pressure causing contact to be made or broken at the lower end or at the upper end of the contact plate on the gauge.

It will also be evident that certain features of the invention may be employed to the exclusionof others and finally to be understood that while for purposes of illustration the present invention has been shown in conjunction with an injector adapted for delivery against high boiler pressures and utilizing supplementary live steam, the invention is equally applicable to injectors delivering against relatively lower pressures and not requiring supplementary live steam.

What I claim is:

' 1. In an exhaust steam injector, a control system including means for admitting auxiliary live steam to the injector and means responsive to overflow from the injector and to variations in exhaust steam pressure for causing the firstmentioned means to admit auxiliary live steam to the injector when the injector overflows or when exhaust steam is not available at pressure suitable for injector operation.

2. In an exhaust steam injector, a control system including a valve for admitting auxiliary live steam to the injector, means comprising an electric circuit and a solenoid operated valve in said circuit for governing operation of said firstmentioned valve and means responsive to variations in exhaust steam pressure for closing said circuit when the pressure is suitable for exhaust steam operation and to open it when such pressure is too high or too low for such operation.

3. In an exhaust steam injector having an exhaust steam supply conduit and an auxiliary live steam supply conduit, a change-over valve for admitting auxiliary live steam to the injector, an electric solenoid operated valve for governing the position of said change-over valve, a pressure gauge, a conduit connecting said gauge with said exhaust steam supply conduit, said gauge comprising an electric contact element and an element movable in response to pressure variations and means providing an electric circuit including said elements and said solenoid for energizing and deenergizing said solenoid in response to variations in the position of said movable element due to variations in exhaust steam pressure.

4. In an exhaust steam injector having an exhaust steam supply conduit and an auxiliary live steam supply conduit, a change-over valve for admitting auxiliary live steam to the injector, an electric solenoid operated valve for governing the position of said change-over valve, said solenoid operated valve being movable upon energization of the solenoid to cause said change-over valve to be closed, a pressure gauge connected to said exhaust steam supply conduit, said gauge comprising relatively movable elements adapted to contact only when the exhaust steam pressure is within a predetermined range and means providing an electric circuit connecting said relatively movable elements and said solenoid.

5. In an exhaust steam injector having an exhaust steam supply conduit and an auxiliary live steam supply conduit, a change-over valve for admitting auxiliary live steam to the injector having a vent conduit for flowof steam governing the position of said valve, an electrically operated valve in said conduit, a pressure gauge comprising contacts for making and breaking an electric circuit controlling said electrically operated valve, and a conduit including a choke connecting said gauge and said exhaust steam supply conduit, said electrically operated valve being located in said vent conduit a substantial distance from said change-over valve whereby said vent conduit between said valves provides a timing chamber producing a lag in operation of the change-over valve with respect to operation of the electrically operated valve.

6. In exhaust steam injector apparatus, a control system including a valve for admitting auxiliary live steam to the injector and electrically operated means for governing the position of said valve, said means being operable to effect closure of said valve when exhaust steam is 5 available at pressure suitable for injector operation with exhaust steam, and to efiect opening of said valve when the pressure of exhaust steam is too high or too low for such operation. 7'

'7. In exhaust steam injector apparatus, a control system including a valve for admitting auxiliary live steam to the injector, electrically operated means for governing the position of said valve, said means being operable to effect closure of said valve when exhaust steam is avail- I able at pressure suitable for injector operation With exhaust steam and to effect opening of said valve when the pressure of exhaust steam is too low or too high for such operation, and means responsive to overflow from the injector for renl dering said electrically operated means inoperative to effect closure of said valve regardless of exhaust steam pressure when the injector is overflowing.

8. In steam injector apparatus including an injector having an overflow, a control system for shifting operation of the injector from exhaust steam operation to live steam operation and vice versa, said system including means for shrifting the injector to live steam operation in response to overflow from the injector.

9. In steam injector apparatus including an injector having an overflow, a control system for shifting operation of the injector from exhaust steam operation to live steam operation and vice versa, said system including means actuated by flow of water through said overflow for insuring live steam operation of the injector during the period of such flow.

10. In steam injector apparatus including an injector having an overflow, a control system including means responsive to overflow from the injector and to the pressure of exhaust steam available for injector operation for shifting the injector to exhaust steam operation only in the absence of overflow and in the presence of a supply of exhaust steam having a pressure within a predetermined range.

11. In exhaust steam injector apparatus of the kind adapted to operate with live steam when a suitable exhaust steam supply is not available, a control system including a first indicating means for indicating the presence or absence of exhaust steam at a pressure suitable for injector operation and a second indicating means for simultaneously indicating operation of the injector as an exhaust steam injector or as a live steam injector, whereby to apprise the operator of proper or improper functioning of the injector when a suitable exhaust steam supply is available.

12. In exhaust steam injector apparatus, a control system including means for admitting exhaust steam to the injector for operation thereof, means for admitting auxiliary live steam to the injector for operation thereof when exhaust steam is not available, and means operating in response to overflow from the injector for causing auxiliary live steam to be admitted to the injector through the second mentioned means.

-13. In exhaust steam injector apparatus, a control system including means for admitting exhaust steam to the injector for operation thereof, means for admitting auxiliary live steam to the injector for operation thereof when exhaust steam is not available, and' electrical means operated by overflow from the injector for causing the second mentioned means to admit auxiliary live steam to the injector to operate the same under conditions unsuitable for injector operation with exhaust steam.

14. In exhaust steam injector apparatus, a control system including means for admitting exhaust steam to the injector for operation thereof, means for admitting auxiliary live steam to the injector for operation thereof when exhaust steam is not available, a valve in the second mentioned means, means comprising an electrical circuit and a solenoid operated valve in such circuit for governing operation of the first mentioned valve, and means actuated by overflow from the injector for altering the electrical characteristics of said circuit to cause auxiliary live steam to be admitted to the injector to 0perate the same under conditions unsuitable for injector operation with exhaust steam.-

15. In apparatus of the character described, the combination with an exhaust steam injector of the type adapted to operate on live steam when exhaust steam is not available, of means indicating the presence or absence of exhaust steam of suitable pressure for injector operation, and. means for indicating that the injector is operating with exhaust steam rather than with live steam.

16. In a control system for exhaust steam injectors of the kind adapted to operate on live steam when exhaust steam is not available, indicating means for indicating that the injector is operating on exhaust steam rather than on live steam, comprising a pressure gauge responsive to exhaust steam pressure and an electrically operated indicator responsive to overflow from the injector.

RALPH G. MAKELY.

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