US2007269A - Injector - Google Patents

Description

H. A. CLAUSS July 9, 1935.

INJECTOR Filed Oct. 18, 1932 2 Sheets-Sheet l INVENTOR B m ATTORNEY H. A. CLAUSS July 9, 1935.

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INVENTOR BY 0 ma ATTORNEY I Patented July 9, 1935 UNITED STATES PATENT OFFICE INJECTOR Application October 18, 1932, Serial No. 638,284

19 Claims.

The present invention relates to injectors and has particular reference to exhaust steam injectors for locomotives.

The conditions under which exhaust steam injectors for locomotives operate are highly variable and as a result the injectors are subject from time to time to spilling or breaking because of variation in one or more of the factors governing the operation of the injector. The. amount of water required to be fed to the locomotive boiler varies from time to time and variation in the amount of water being fed by the injector affects its stability of operation under a given set of operating conditions. In general, it may be said that the injector becomes increasingly unstable as its minimum or maximum capacity is approached under given set or" working conditions and with variations in such factors as suction water temperature, exhaust steam pressure and the like, the range of capacity of the injector with stable operation will vary considerably.

It will be evident that spilling at the overflow of the injector or breaking of the injector should be avoided since. the former involves not only undesirable loss of water but is indicative of the approach of an operating condition leading to breaking of the injector. Breaking of the injector, that is, such cessation of operation as to cause the injector to lose its suction and to cause steam to blow through. the injector and back into the suction water passage is, of course, highly undesirable and to be avoided.

Injectors, as applied to locomotives, are usually placed in. locations where it is diilicult if not impossible for the operator to observe overflow conditions from the cab of the locomotive and because of the many other duties of the operator, usually the fireman, the operator cannot give his undivided attention to the operation of the injector for the purpose of so adjusting the control of the injector as to prevent spilling.

A principal object of the present invention is to provide means in the nature of an automatic telltale or alarm for apprising the operator of the injector that the injector is operating under conditions producing or likely to produce spilling or breaking of the injector, so that the operator may readjust the control of the injector to insure continued stable operation thereof under the conditions existing at the moment.

In accordance with the invention an alarm is employed which is responsive to a condition withvention contemplates the employment of an electrically operated alarm giving the desired alarm upon rise of overflow pressure in the injector to a value indicative of approach to or actual spilling.

The still more specific nature of the invention together with the more detailed objects and advantages thereof will appear more fully in conjunction with the ensuing description of suitable apparatus for carrying the invention into effect, as illustrated in the accompanying drawings, in which:

Fig. 1 is a side elevation, partly in section of an exhaust steam injector embodying the invention as applied to a. locomotive;

Fig. 2 is a longitudinal central section, on enlarged scale, of a pressure responsive device shown in elevation in Fig. 1, and

Fig. 3 is a section similar to Fig. 2 of another form of pressure responsive device.

Turning now more particularly to Fig. l of the drawings, the outline of a cab of a locomotive is indicated generally by the dash lines A. Beneath the cab is mounted on the frame of the locomotive (not shown) the exhaust steam injector indicated generally at B.

Injector B is supplied with exhaust steam through conduit l0, water is supplied through conduit H and live steam for operating the injector when exhaust steam is not available and for operating the injector control system is sup plied through conduit H in which is located the main control valve l3.

The amount of Water fed by the injector is varied through the medium of the control handle l4 located in the cab and the injector delivers water to the boiler through the conduit IS.

The details of the internal construction of the injector and of the control system therefor are not material to the present invention and need not be described in detail herein.

The injector illustrated is provided with the usual overflow chamber l6 controlled by the over flow valve I! which operates to control communication between overflow chamber IG and the overflow discharge pipe I8.

Control of the overflow valve Il may be efiected in any suitable known manner but for purposes of illustration I have shown the form of over flow valve control disclosed in United States Patent No. 1,076,220 granted October 21, 1913 to R. D. and J. C. Metcalte in which the overflow valve is held in closed position during operation of the injector by pressure of the water delivered by the injector. In the embodiment illustrated a small piston or plunger it, in communication with the delivery chamber 20, projects through a suitable stufiing box 2i and actuates the lever 22 pivoted at 23 to close overflow valve 5? when operation of the injector commences and normal delivery pressure is established. A spring 24 is advantageously employed to maintain piston l9 in retracted position and to permit free opening of overflow valve ll when starting the injector.

A pressure responsive device indicated generally at C and to be hereinafter more'fully described, is in communication with the overflow,

chamber l 8 and operates to control an electric circuit indicated generally at D and energized from any suitable source of electrical energy such as the generator indicated at E. Obviously the supply of energy may be from a storage battery or the like. The circuit D comprises a connection 25 leading from thesource of current E to the pressure responsive device C, a connection 26 leading from the latter to one terminal of a visual alarm F and a connection 2? from the other terminal of the alarm or telltale F back to the source of current.

I The telltale F is advantageously in the form of a light of the bullseye type comprising a suitable casing 28 enclosing a lamp 29, to the terminals of which are connected the connections 26 and 21, and having a bullseye 39, preferably red, illuminated by the lighting of lamp 29.

Turning now to Fig. 2, the pressure responsive device D cbmprises a suitable" casing 3i the lower end of which is closed by the threaded cap 32 which is in turn threaded at 33 for attachment to the casing of the injector. A bellows 34 is secured to the cap 32 and is adapted to be placed in communication with the overflow chamber of the injector by way of the bore 35. Bellows 34 has secured thereto the stem 35, the upper end of which is guided in the plug 3'5 screwed into casing 3i. Plug .i'i'provides an adjustable abutment for one end of spring 38 around stem 36, the other end of this spring bearing against the upper end of the bellows structure. As will be evident from the drawings, spring 38 resists the tendency of bellows 34 to expand under the iniluence of internal pressure and the force exerted by spring 38 may be varied by suitable adjustment of the plug 3?, which may be eifected through a suitable opening 39 in the side of the casing 35. Any suitable locking device such as that indicated generally at Ml may be employed for holding the adjustable plug Si in position.

The upper end of the stem 36 carries a suitably insulated contact point ii which is connected to the connection 25, the latter advantageously passing through the side wall of casing 3i through a suitable insulator 22. The top of casing 3i is closed by a cap 53 of suitable insulating materialwhich is held in position by studs 44 and through which is threaded the pin 55 the lower end 46 of which provides a contact point adapted to abut the contact point i Pin is connected to the connection 25 and the position of the point 45 with respect to point ll is adjustable by screwing pin :35 inwardly or outwardly through the cap 43. Pin 4-5 is advantageously provided with the usual lock nut ll for holding it in properly adjusted position.

The operation of the apparatus is as follows: If the injector is operating properly there is either a vacuum or relatively low pressure in the overflow chamber of the injector. Under these conditions the spring 38 maintains the contact point 4i spaced from the contact point 46. With the contacts separated, the circuit D is broken and the bullseye 3B is not illuminated. The same condition also holds true when the injector is not in operation since when the injector is not operating there is no pressure in bellows 3%.

If for example, with the injector operating properly, the water adjustment is changed by moving the water regulator too far toward minimum or maximum position for the other conditions obtaining at the moment, the pressure in the overflow chamber of the injector will increase and the injector will tend to spill. In the form of injector illustrated, the overflow valve is held in closed position due to the delivery pressure acting upon the piston IE but the difference in areas between piston l9 and valve ill and also the relative lengths of the arms of the lever 22 are such that upon increase of the pressure in the overflow chamber to a certain value, valve ill will be lifted from its seat against delivery pressure to relieve the pressure in the overflow chamber. This does not necessarily involve cessation of operation of the injector but it is indicative of unstable operation which may if continued lead to failure of the injector to continue to deliver water to the boiler while spilling continuously through the overflow, or to breaking of the injector resulting in loss of suction and blowing of steam through the overflow and water passages.

Through the adjustments provided for the contact point it and also for spring 38, the pressure responsive device D may be set so that contact between points 2-! and $5 is made when the pressure in the overflow chamber it approaches the pressure at which spilling will normally take place with any given injector. Different injectors, operating under difierent conditions, will tend to spill at different overflow chamber pressures but the simple adjustment provided by the device illustrated permits a proper initial adjustment which will give the desired warning of the approach to unstable operating conditions. Obviously, the adjustment may be set so that the warning given by the device Will occur either at a pressure well below that at which spilling is likely to occur or it may be set so that warning is not given until actual spilling commences. The former adjustment is, however, to be preferred over the latter. At the same time the pressure for which the warning is set should not be so low as to materially impair the range of capacity through which the operator can work the injector without incurring a warning that a condition of unstable operation is being approached.

The pressure at which the injector will spill, particularly in injectors of the type employing overflow valve control of the character illustrated in 1, will vary with variations in boiler pressure. It will be evident from a consideration of the overflow valve arrangement shown in Fig. 1 that if the boiler pressure, and consequently the delivery pressure of the injector, falls, the overflow pressure required to lift valve 9? will also fall and conversely if the boiler and delivery pressures rise it will require a higher delivery pressure to open valve ll.

If it is desired to take this variation into account a pressure responsive device D of the type illustrated in Fig.3 may be employed. In this device the casing 3 l is provided with a bellows 34' adapted to communicate with the overflow chamber through passage 35 and carrying the movable contact point ll The general arrangement and provision for adjusting the positionof this contact point by means of spring 38 is similar to that described in connection with Fig. 2. In the present arrangement, however, the movement of point 4| under the influence of the pressure in bellows 34 is modified by the counter pressure of the water delivered by the injector so that movement of contact 4! is responsive to a differential pressure. In the embodiment illustrated, the insulating member 43' carrying the fixed contact point 46' is mounted within the casing which carries an extended cap 48 to which is attached a second bellows 49. The free end of bellows 49 acts against a pair of pins 56 which extend through suitable openings in member 43 and abut against the head 5| carried by stem 36 and serving as a mounting for the contact point 4|. A conduit 52 provides a connection for placing bellows 49 in communication with the delivery chamber or any suitable point in the delivery conduit 15 leading from the injector.

The contact point 4! may be connected to the connection and contact point 46' to connection 26 in the manner already described.

It will be evident that the device just described provides what is in eflect a differential piston but the bellows construction employed is to be preferred since it eliminates the necessity for the use of any packed joints in connection with the movable pressure responsive elements.

The maximum pressure occurring in the overflow chamber before spilling takes place is very much lower than the delivery pressure and consequently in order to secure the proper movement of the movable contact point the bellows 49 should be of much smaller area than the bellows 34'. It will be obvious that diaphragms or other equivalent elements may be employed in place of the bellows illustrated.

As between the two forms of pressure responsive devices shown in Figs. 2 and 3, that which is illustrated in Fig. 3 provides a somewhat more precise indication of the approach to a spilling condition but on the other hand the device illustrated in Fig. 2 has the advantage of relative simplicity and I have found that under the conditions ordinarily obtaining in locomotive operation, the arrangement shown in Fig. 2, when given a proper initial adjustment, provides a warning sufliciently accurate for purposes of practical operation.

I consider the employment of an alarm of the type indicated to be of substantial importance since practical experience has shown that an alarm of a relatively arresting nature is required in view of the operators many other duties and the alarm must also be as effective in darkness as in daylight if proper attention is to be given to the warning given by the alarm. The electric operation of the warning permits wide latitude in the choice of location for the alarm and also makes possible the employment of an audible warning device such as a bell, but an alarm of the type giving a visual signal is to be preferred.

Numerous changes and modifications may be made in the apparatus as shown herein by way of illustration without departing from the invention, the scope of which is defined by the appended claims when construed as broadly as is consistent with the state of the prior art.

What is claimed is:

1. Apparatus of the character described comprising, in combination, an injector having an overflow chamber, an electric circuit including an alarm device remote from the injector, and a pressure responsive device adjacent to the injector and in communication with said overflow chamber for altering flow of current through said circuit so as to cause the alarm to be operated when the overflow pressure approaches that at which spilling of the injector will occur.

2. Apparatus of the character described comprising, in combination, an injector having an overflow chamber, an electric circuit including an alarm device remote from the injector, and a pressure responsive device adjacent to the in jector, said pressure responsive device comprising contacts relatively movable to alter flow of current through said circuit and a pressure responsive bellows in communication with said overflow chamber for causing relative movement of said contacts.

3. Apparatus of the character described comprising, in combination, an injector, an electric circuit including a visual alarm, and a pressure responsive device operable in response to variations in the diflerence in pressure between the overflow pressure of the injector and the delivery pressure thereof for altering the flow of current in said circuit to cause operation of the alarm under predetermined conditions of injector operation.

4. Apparatus of the character described comprising, in combination, an injector having an overflow chamber, a pressure responsive device adjacent to the injector comprising a pressure responsive member in communication with said overfiow chamber and adjustable contacts including a contact operatively connected with said pressure responsive member, and an electric circuit including an alarm device, flow of current through said circuit being governed by said contacts.

5. Apparatus of the character described comprising, in combination, an injector having an overflow chamber, a pressure responsive device adjacent to the injector, said device comprising a bellows in communication with said overflow chamber, adjustable contacts adapted to be closed or opened upon movement of said bellows under the influence of variations in overflow pressure, an alarm device, and electrical means controlled by said contacts for causing said alarm device to be operated when the pressure in the overflow chamber reaches a predetermined value.

6. Apparatus of the character described comprising, in combination, an injector, a pressure responsive device adjacent to the injector, said device comprising a member responsive to overflow pressure in the injector, a spring acting on said member in opposition to said pressure, adjusting means for varying the force exerted by said spring, and an electric circuit including a warning device and relatively movable contacts for controlling said circuit, one of said contacts being operatively connected with said member.

7. Apparatus of the character described comprising, in combination, an injector, a pressure responsive device adjacent to the injector, said device comprising a bellows responsive to overflow pressure in the injector, a spring acting on said bellows in opposition to said pressure, adjusting means for varying the force exerted by said spring, and an electric circuit including a warning device and relatively movable contacts for controlling said circuit, one of said contacts being operatively connected with said bellows.

8. Apparatus of the character described comprising, in combination, an injector, a pressure responsive device comprising a first pressure responsive member subject to the influence of the overflow pressure of the injector and a second pressure responsive member'subject to the influence of the delivery pressure of the injector,

"means operatively connected to and movable under the influence of said pressure responsive members, a fixed contact, a contact moving with said means and an electric circuit including an alarm device controlled by said contacts.

9. Apparatus of the character described comprising, in combination, an injector, a pressure responsive device comprising a flrst bellows subject to the influence of the overflow pressure of the injector and a second bellows subject to the influence of the delivery pressure of the injector, means operatively connected to and movable under the influence of said bellows, a fixed contact, a contact moving with said means and an electric circuit including an alarm device controlled by said contacts.

10. Apparatus of the character described, comprising in combination an exhaust steam injector having an overflow chamber, an overflow valve controlling the flow from said chamber and means for loading said valve due to delivery pressure from the injector, and an electrically operated alarm responsive to pressure in said chamber for warning an operator of relatively unstable operation of the injector.

11. Apparatus of the character described, comprising in combination an exhaust steam injector having an overflow chamber, an overflow valve controlling the flow from said chamber and means for loading said valve due to delivery pressure from the injector, and an electrically operated alarm responsive to pressure in said chamber, said alarm providing a visual signal for warning an operator of relatively unstable operation of the injector.

12. Apparatus of the character described, comprising in combination an exhaust steam injector having an overflow chamber, an overflow valve controlling the flow from said chamber and means for loading said valve due to delivery pressure from the injector, a pressure responsive device comprising a pressure responsive member in communication with said overflow chamber and adjustable contacts including a contact operatively connected with said pressure responsive member, and an electric circuit including an alarm device, flow of current through said circuit being governed by said contacts.

13. Apparatus of the character described, comprising in combination an exhaust steam injector having an overflow chamber, an overflow valve controlling the flow from said chamber and means for loading said valve due to delivery pressure from the injector, a pressure responsive device comprising a pressure responsive member in communication with said overflow chamber, adjustable contacts adapted to be closed or opened upon movement of said device under the influence of variations in overflow pressure, an alarm device and electrical means controlled by said contacts for causing said alarm device to be operated when the pressure inthe overflow chamberreaches a predetermined value.

14. Apparatus of the character described, comprising in combination an injector having an overflow chamber, an overflow valve controlling the flow from said chamber and means for loading said valve due to delivery pressure from the injector, an electric circuit including an alarm, and a pressure responsive device operable in response to variations in the difference in pressure between the pressure in said chamber and the delivery pressure of the injector for altering flow of current in said circuit to cause operation of the alarm under predetermined conditions of injector operation.

15. Apparatus of the character described, comprising in combination an injector, an alarm, means for operating the alarm under the in: fluence of overflow pressure, and means operable under the influence of delivery pressure for modifying the value of the overflow pressure required to operate the alarm.

16. Apparatus of the character described, comprising in combination an injector, an electrically operated visual alarm, means for operating the alarm under the influence of overflow pres-' sure, and means operable under the influence of delivery pressure for modifying the value of the overflow pressure required to operate the alarm.

17. Apparatus of the character described comprising, in combination an injector, an alarm, and electrical means for operating said alarm, said means being responsive to a pressure condition within the injector to operate said alarm upon rise of said pressure condition to a value approaching but below that at which spilling of the injector will occur.

18. Apparatus of the character described, comprising in combination, an injector, an alarm, and electrical means for operating said alarm, said means being responsive to the overflow pressure within the injector to operate said alarm when the overflow pressure rises to a value approaching but below that at which spilling of the injector will occur.

19. Apparatus of the character described comprising, in combination, an injector havingan overflow chamber, an electric circuit including an alarm device remote from the injector, and a pressure responsive device in communication with said overflow chamber for altering flow of current through said circuit so as to cause the alarm to be operated when the overflow pressure rises to a predetermined value, and adjustable means for varying the pressure at which said pressure responsive device causes alteration of the flow of current through said circuit whereby to permit the device to be adjusted in relation to the particular operating conditions of a given injector installation so that the alarm will be operated when the overflow pressure approaches that at which spilling of the injector will occur.

HAROLD A. CLAUSS.

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