US2053441A - Injector - Google Patents

Description

I Sept. 8, 1936. E. RAWsoN ET Al.

INJECTOR Filed May 18, 1955 5 Sheets-Sheet 1 SePt- 8, 1936 E. RAwsoN r-:T AL 2,053,441

INJECTOR Filed May 18, 1935 3 sheets-sheet 2 INVENTOR n Josep/f /C Gear/:Mn

BY EMA/Z/EL. RAM/5 om AT'TORNEY Sept. 8, 1936. E RAWSON ET'AL 2,053,441

INJECTOR Filed May 18., 1955 5 Sheets-Sheet 3 INVENTOR dosfpff Gaf/FFW.

BY EMA/WEL ,QM/59M .,/z ATTORNEY Patented Sept. 8, 1936 UNrre srAfTEs INJEoToB.

Emanuel Rawson, North Bergen, and .Joseph Griiin, Teaneck, N. J., assgnors 'to The Superheater Company, New York, N. `Y.

application May 1s, 19s5,.-sei-1a1No..22,126 6 claims. (C1. 1%;26'5) There are certain devices on modern locomotives whose operation is in one way or'another tied up with the presence or absence of exhaust steam of suitable pressure in the passages between the main engine and the exhaust nozzle. As examples of such devices, exhaust steam injectors, feed water heaters and .so-called drifting valves may be mentioned. In the case of exhaust steam injectors it is essential that the cessation of the 10 exhaust steam supply shall not interrupt the operation of the device; and in the case of exhaust-heated feed water heaters it is highly desirable to continue the heating of the feed water on its Way to the boiler even if the exhaust steam supply ceases. Drifting valves are put into action to supply live steam from the boiler to certain points when there is no exhaust steam coming from the engine to fill the nozzle and the exhaust cavities' and passages between it and the 2() engine. These three illustrations will serve to exemplify the class of devices for which the present invention is of interest. The invention will be described in detail as applied to an injector and then briefly as applied to a feed water heater.

It will be understood that there is no intention that this be construed as a limitation to the devices referred to.

In providing means for allowing live steam to ow to exhaust steam injectors when required and interrupting such flow when not required, the impulse for bringing such means into action has in the past been taken from various points. O'bviously the failure of exhaust steam pressure may be taken directly to bring the means into action to supply substitute live steam; and inasmuch as the presence or absence of exhaust steam is in general directly dependent on the presence or absence of live steam in the passage between the mainV throttle and the engine the means can be 40 actuated in response to pressure in the steam pipe or valve chest. Both of these sources of impulse have been used in the practice in the past.

The present invention has for its purpose the provision of means using an entirely different source for such impulse than has been utilized heretofore, and one which results in important advantages.

The invention will be described with reference to the accompanying drawings. In these drawl ings, Fig. 1 illustrates a more or less fragmentary tional View of 4a locomotive exhaust nozzle andthe lower portieri ofthe associated stack showings. variation in 'the point from which the actuating impulse -is taken. Figs. 5 fand 'Gare similar views showing further variations of this same detail; Fig. 'lffis'a top view of La nozzle illustrating a still further variation `of the same detail; Fig. 8 is a view `similarlto iFig. "1, 4'show-ing 'the-application of the invention -to aife'edwater heater installation; l and'Fig. t9 -is a-seotiona'lview of a detail of Fig. 8. 10

'The Ageneral arrangement of the Japparatus 'as applied 'to an `exhaust Asteam injector on a locomotive is shown "in Figs. 1 and 2. The boiler of the locomotive appears at 2, the stack'at 4 and the exhaust nozzle at "6. The injector 8 is supported byjany'des'ired means in the usual position under the 'cab ID.. Exhaust steam "from the engine for operation `of the injector 'is supplied by means of pipe I'2,-andfeed water is supplied to the injector by pipe I4.. Live steam vfrom turret I6, used for 29 operating lthe various controls and to supplement and if'required'replace the exhaust steam, reaches the injector through ,pipe IB, this supply being controlled by the main control or starting valve 20. The water is forced by the injector into the boiler through pipe 22. 24 is the usual overflow, and 2.6 is the usual regulating handle for controlling vthe water supply tothe injector.

Referring to Fig. 3, the exhaust steam flow to the injector is controlledrby -means of valve 28, while lthe Vflovvof liVes'team to the injector to take vits place when the exhaust supply fails is controlled .by the `.so-.called automatic valve 46. 'I'hese l.two valves, and lthe operating `mechanism within the .injector generally, are preferably left as heretofore .and not modified for our purpose. Familiarity .with .this mechanism and its operation .is .assumed herein, .and willnot be described. United .States Patent 1,984,547 andReissue Patent.19,229 fully ydisclose .and describe thesev features: .and their actions. The point of interest in yconnection with the present invention .is that whenthe main control or starting valve 2D (Fig. 1) hasbeenepened, the question whether'the in- 45 jector Hwill work on exhaust ysteam l or on live steam `will-'depend upon .the pressure .prevailing in chamber 52- Steam is admitted .to thischamber .-frompipe lI-8 through ybranch 48, duct 5|] .and choke-port 18. A connecting pipe leads from 50 the chamber 52 to a point of low pressure, e. g. the exhaust steam -space within the injector, and this `connecting pipe is equipped with a Valve 82 which in .the ordinary practice is of the needle-valve type. The `relative sizes of choke 18 and pipe 80 and valve 82 are such that when valve 82 is open the pressure in chamber 52 is effectively released.

In prior practice, as illustrated in the patents referred to, the position of the valve in connecting pipe is responsive to the pressure at some point in the exhaust passages or in the pipe supplying operating exhaust steam to the injector from the main engine exhaust. When the pressure in the passages or in this supply pipe falls below a certain point, the valve opens and releases the pressure in chamber 52, thus setting into action the means for shutting exhaust valve 28 and opening the automatic valve 46 to supply live steam.

Our invention, as stated above, takes the impulse for governing the position of needle valve 82 from a different point than has been done heretofore with resulting important advantages.

The change requires some changes in the mechanism actuating valve 82.

In Fig. 3 it will be noted that the upper end of -this needle valve 82 extends through the bottom and into the interior of Vthe casing 90. The lever 92, mounted pivotally at 94, bears with one end against the top of needle valve 82, its other end being pivotally connected to the lower end of pin 93. This pin 93 is carried by diaphragm 95 which separates the interior of casing 90 into an upper space 96 and a lower space 98. The lower portion 98 of the space in the casing communicates with the atmosphere through an opening |00, whereas the space 96 is, by means of the pipe |02, put into open communication with the interior of the smoke box |04. (See Figs, 1 and 2.) A spring |06, bearing against the upper side of diaphragm 95, tends to depress the diaphragm, the tension of this spring and hence the pressure difference on the two sides of the diaphragm required to raise the diaphragm being adjustable by means of the screw |08.

Theoperation of this portion of the device is as follows: When the throttle of the locomotive is Open and exhaust steam issues from nozzle 6, a partial vacuum is createdin the smoke box |04, this being the ordinary means for creating the draft for the locomotive furnace. The pressure in chamber 96 of thel casing 90 becomes correspondingly reduced, thus allowing the atmospheric pressure on the lower side of diaphragm 95 to move the diaphragm upwardly, thereby bringing the lever 92 into action to keep needle valve 82 in its closed position. This closed position of thev needle valve results in allowing pressure to build up in chamber 52, thereby placing the injector mechanism in the known way into position for exhaust steam operation.

If now the main throttle is closed by the engineer, the pressure in the smoke box |04,` and consequently that in space 96 above diaphragm 95, rises to full atmospheric pressure. As a, consequence the diaphragm 95 becomes somewhat depressed under the combined influence of this full atmospheric pressure and of spring |06, thus releasing the engagement of the end of lever 92 with the needle valve 82 and permitting pressure in pipe 80 below the valve to open it. The result of this open position of needle valve is to release the pressure in chamber 52, which in turn in the known manner shifts the injector mechanism to live steam operation.

As far as exhaust steam injectors are concerned, taking the impulse from the smoke box as described results in certain definite advantages over prior forms, especially the one referred to which takes the impulse from the exhaust steam passages or the pipe supply in exhaust steam to the injector. By our arrangement the danger of freezing up of the diaphragm chamber is reduced, and the danger of the pipe which carries the impulse to the diaphragm being plugged up with oil and carbon is removed. The diaphragm in our arrangement is no longer exposed to high temperatures and therefore may be made of rubber. Whereas in the former arrangement the diaphragm was apt to be subjected to excessive pressures and damaged or entirely ruptured 'during tests on the locomotive, the present arrangement removes this `danger entirely and from Y this stand-point, too, rubber will be satisfactory;

and inany event the diaphragm, no matter of what material, will not be subject to injury. It is diflicult to design a metallic diaphragm strong enough to withstand high working pressures and yet sensitive 'enough to actuate the control at very low pressures and in response to very small variations. This was a requirement that had to be met in the old arrangement. The avoidance of all high pressures on the diaphragm and the possibility ofV using rubber for the diaphragm solves this diiculty. One further important advantage is that the arrangement obviates a rapidly alternating fluctuation from exhaust steam operation t0 live steam operation and back, which occurs at times in the old arrangement mentioned when working close to theV point Vof changeover. This condition existsV when there is exhaust steam present but the pressure is not sufcient for continuous exhaust steam operation. The injector will change over to'live steam operation and this will at once result in the pressure in the exhaust steam supply pipe building up suiiiciently to cause the injector to change back to exhaust steam operation. The opening of injector exhaust steam valve lowers to exhaust pressure again and the cycleV is repeated. By our arrangement this objectionable action is oompletely avoided.

In practice the decrease in pressure in the smoke box referred to above will ordinarily be suiiicient to operate the device as above described.V and the end of pipe |02 may be placed as Shown in Fig. 2. In some cases it may be desirable or necessary to accentuate the degree of the partial vacuum affecting the pressure in space 96. The variations illustrated in Figs. 4, 5, Gand 7 are intended to eiect this. In the variation according to Fig. 4 the end of pipe |65 is broughtV directly into the exhaust nozzle 6 ending near the tip of this nozzle and opening in the direction of the exhaust steam ow. This location will result in a much accentuated partial vacuum within the pipe |04 and therefore within space 96.

If a further increase in this vacuum is desired, an arrangement according to Fig. 5 may be adopted. In this variation a Venturi shaped envelope ||0 is placed around the end of the pipe |02. This causes a violent ej-ecting action and further emphasizes the partial Vacuum formed.

Another means of obtaining an increase in the partial vacuum is that of Fig. 6. The end of the pipe |02 is brought into proximity of the jet issuing from nozzle 6 without being inserted directly into the jet. The ejecting'action of thejet is more emphasized here than it is where the end of pipe |02 is as shown in Fig. 2. If desired, the

' end of the pipe |02 may be given a slit-shaped form as in Fig. 'l which is a top view of the end of the pipe, the slit preferably being curved to conform to the contour of the steam jet issuing from the nozzle 6.

Referring now briefly to a further device utilizing our invention, there is shown in Fig. 8 a feed water heater on a locomotive, the whole system being generally similar to a known one, shown for example in U. S. Patent 1,952,933 granted on March 27, 1934, to R. G. Makely. The heater 200 (Fig. 8) is mounted in the usual elevated position at the front of the smoke box. Water is forced by pump 284 through pipe 296, heater 200, and pipe 208 into the boiler. Exhaust steam to heat the feed water is supplied by means of pipe l2a. When no exhaust steam for heating is available, it is replaced by live steam taken by means of branch 2|Da from pipe 2I0 which furnishes operating steam to the pump. This supply is controlled by valve 2I2, connected to piston 2M. (See Fig. 9.) A leak port 2I6 permits steam to leak to the space above piston 2 I4 and to build up pressure, thus holding valve 2l2 to its s-eat. If the pressure above piston 2M is released, valve 2I2 will be opened by the unbalanced pressure on the lower side of the piston. This release is effected by the diaphragm-actuated valve in casing 9U, Fig. 8. The construction of the parts in this casing is just like that described in conn-ection with Fig. 3. Pipe |0211, leading from some point in the smoke box, establishes smoke box pressure in chamber 96. When this is sufficiently low, valve 82 will be held to its seat, allowing pressure to build up above piston 2M; and when it rises to a predetermined point, valve 82 will open and release pressure above the piston. Thus, when the main throttle is open and therefore exhaust steam is available, it will do the feed water heating; while at times when no exhaust is available, live steam will replace the exhaust steam, if the pump is being supplied with steam. A number of the advantages of the new arrangement pointed out above are also present here.

That the inventive idea may be used in connection with some other appliances will be clear from the above.

What we claim is:

l.. In an injector control system for an injector operating alternatively with live steam or with ex haust steam which is provided with an automatic change-over valve for shifting from live steam to exhaust steam operation or vice versa and used on a locomotive using a jet of exhaust steam from the engines for reducing the pressure in the smoke box thereby creating draft for the furnace, the combination of a valve whose position determines on which kind of steam the injector is to operate, and means responsive to pressure conditions in the smoke box to determine the position of the valve.

2. In an injector control system for an injector operating alternatively with live steam or with exhaust steam which is provided with an automatic change-over valve for shifting from live steam to exhaust steam operation or vice versa and used on a locomotive using a jet of exhaust steam from the engines for reducing the pressure in the smoke box thereby creating draft for the furnace, the combination of a valve whose closing 4causes the injector to operate on exhaust steam and whose opening causes the injector to operate on live steam, a diaphragm actuating the valve, and means to subject one side of the diaphragm to smoke box pressure.

3. In an injector control system for an injector operating alternatively with live steam or with exhaust steam which is provided with an automatic change-over valve for shifting from live steam to exhaust steam operation or vice versa and used on a locomotive using a jet of exhaust steam from the engines for reducing the pressure in the smoke box thereby creating draft for the furnace, the combination of a valve whose closing causes the injector to operate on exhaust steam and whose opening causes the injector to operate on live steam, a diaphragm subject on one side to atmospheric pressure and on the other side to smoke box pressure, and means whereby movement of the diaphragm due to atmospheric pressure closes the valve and movement in the opposite direction leaves it free to open.

4. In an injector control system for an injector operating alternatively with live steam or with exhaust steam which is provided with an automatic change-over valve for shifting from live steam to exhaust steam operation o r vice versa and used on a locomotive using a jet of exhaust steam from the engines for reducing the pressure in the smoke-box thereby creating draft for the furnace, the combination of a valve whose position determines on which kind of steam the injector is to operate, a diaphragm, means to subject one side of the diaphragm to a substantially constant pressure and the other side to smoke box pressure, and means to cause movement of the diaphragm due to the constant pressure to close the valve and movement in the opposite direction to leave it free to open.

5. In an injector control system for an injector operating alternatively with live steam or with exhaust steam which is provided with an automatic changeover valve for shifting from live steam to exhaust steam operation or Vice versa and used on a locomotive using a jet of exhaust steam from the engines for reducing the pressure in the smoke box thereby creating draft for the furnace, the combination of a valve whose closing causes the injector to operate on exhaust steam and whose opening causes the injector to operate on live steam, a diaphragm subject on one side to atmospheric pressure and on the other side to pressure prevailing in proximity to the exhaust steam jet, and means whereby movement of the diaphragm due to atmospheric pressure closes the valve and movement in the opposite direction leaves it free to open.

6. In an injector control system for an injector operating alternatively with live steam or with exhaust steam, which is provided with an automatic change-over valve for shifting from live steam to exhaust steam operation and vice versa, and used on a locomotive using a jet of exhaust steam from the engines for reducing the pressure in the smoke-box thereby creating draft for the furnace, the combination of a valve whose position determines on which kind of steam the injector operates, pressure responsive means determining the position of the valve, and a duct placing said pressure responsive means into communication with the interior of the smoke-box at a point where the effect of the exhaust jet is particularly pronounced.

EMANUEL RAWSON. J OSllPH F. GRIFFIN.

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