US648040A - Injector. - Google Patents

Description

Patented Apr. 24, |901 J. C. & B. D. METCALFE.

INJECTOR.

(Application filed Jan. 3, 1900.)

(No ModeAl.) 2 Sheets-Sheet i.

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No. 648,040. Patented Ap'r. 24, |900.

. J. G. R. D. METCALFE.

INJECTDB.

- (Application led Jan. 3, 1900.) (No Model.) 2 Shees-Sheet 2` TH: r-onnls PETERS co., vuoto-uma, WASHINGTON, n, c.

' union@ JAMES CROXON METCALFE AND RICHARD DAVID METCALFE, OF ABERYSTWITH, ENGLAND.

INJECTOR.

SPECIFICATION forming part of Letters Patent No. 648,040, dated April 24, 1900.

Application filed January 3, 1900. Serial No. 243. (No model.)

To @ZZ whom t may concern:

Beit known that we, JAMES CRoxoN MET- CALFE and RICHARD DAvID METCALFE, subjects of the Queen of Great Britain, residing at Aberystwith, county of Cardigan, England, have invented certain new and useful Improvements in Injectors; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters of reference marked thereon, which form a part of this specification.

Our invention has relation to steam-boiler injectors, applicable also to combined exhaust and supplementary live steam injectors.

It has been the custom before our present invention to control the overiiow through thel medium of a vdiaphragm-eontrolled pistonheaded valve unseated by low pressure in the overflow-chamber in starting and seated to close the overflow branch by high pressure in the delivery-chamber after the jet has been fully established. By low pressure We -mean that pressure which generally exists in the overflow-chamber of an injector from the starting to the timewhen the jet is fully established and varying from a pressure below the working pressure of the injector to a partial vacuum,l and by high pressure we mean that pressure which exists in the deliverychamber after the jet has been fully established and the injector is Working against boiler-pressure. The disadvantages of diapragms for controlling a valve are Well understood. The greatest objection thereto, irrespective of their rapid wear, is that after they have been in use for a comparatively-short time they become more or less unreliable in action owing to their expansion or stretching, the chamber in which the diaphragm is contained being necessarily shallow, the overflow-valve having usually but very slight play from and to its seat.

One of the objects of our invention is to avoid the disadvantages inherent to diaphragm-controlled overflow-valves, and this we attain by using instead of a diaphragm a lever acting on the stem of the overflow-valve and a piston inliuenced by the high or working pressure acting upon said lever.

In that type of injectors operated by exhaust-steam in Which-the combining-cone has a Hap or portion hinged to open into the overflow-chamber under the influence of low or starting -pressure for purposes well understood and knownas flap combining-cones the flap is liable to Iiy open or partially open after the injector is fully started under a sudden inrush of exhaust-steam, which is more liable to occur in heavy-blast-locomotive injectors, and this, as is well known, materially interferes with the proper working of the injector.

The further object of our invention is to prevent the flying open or the partial opening of the combining-cone tlap under a sudden inrush of exhaust-steam, and this we attain by means of a piston influenced by high or Working pressure and suitable means, as a plunger operated by said piston and acting upon the iiap of the cone, to hold said flap to its seat; but that our invention may be fully understood we will describe the same in detail,refe rence being had to the accompanying drawings, in which- Figure 1 is a longitudinal axial section of an injector having a flap combining-cone and embodying our improvements. Fig. 2 is a similar view illustrating our improvements applied to a combined exhaust and supplementary live steam injector, and Fig. 3 is a section taken on line :r of Fig. 2.

Referring to Fig. 1, C indicates the casing; c, the exhaust branch; Vthe usual throttlevalve therein; C', the steam-cone; C2, the Iiap combining-cone, having the usual flap portion c?, and C3 the delivery cone, said combining and delivery cones being screwed together and into the delivery end of the casing C, said delivery-cone having its outer open end closed by a screw-plug c3 and provided with ports c in communication with the delivery branch c4. (Shown partly in dotted lines and partly in full lines.)

C4 indicates the water branch; C5, the overflow branch, and C6, a live steam branch carrying a nozzle c6, extending through the exhaust-steam cone C into the flap combining- IOO cone C2, so that in the absence of exhauststeam the injector can be worked with live steam.

The exhaust-steam cone C' for well-known purposes is adjustable toward and from the combining-cone C2 by means of a spindle s, usually provided with a hand wheel (not shown) and working in a stuffing box gland and carrying a crank-disk d, whose crankpin works in a cross-groove in the periphery of said exhaust-steam cone.

The construction of the injector thus far described is a well-known one, and our improvements thereon consist in forming in the passage leading from the overflow-chamber c5 a valve-seat for a valve V', Whose stem extends through a discoidal plug p, screwed into an opening in the aforesaid passage c6. The stem of the valve V' abuts against one arm Z of a centrally-fulcru med rock-lever L, and against the other arm Z' of said lever abuts the rod of a piston P, that works fluidtight in the bore of a cylindrical projection c7 from the casing C, said bore communicating with an annular recess or channel es,

-formed in the inner periphery of casing C.

The channel e8 communicates with the interior of the delivery-cone C3 through one of its ports c', thus forming a pressure-chamber between said cone and the casing C.

In starting the injector, whether by means of exhaust or live steam, the pressure-in the delivery-cone C3 will of course be lower than in the overflow-chamber c5, so that the valve V', controlling the overflow, can open freely under said pressure. As soon, however, as the jet is established and the injector begins to work the pressure in the overflow-chamber drops to a partial vacuum, while in the annular chamber e8 the pressure will have risen to Working pressure, Which, acting 011 the piston P and through the lever L on the 'stem of the valve V', will move the latter to and hold the same firmly on its seat as long as the injector is working properly, thus obviating the use of a diaphragm for controlling the overfiow-valve.

As shown, the piston P is a comparatively long one and has annular grooves formed therein from distance to distance and is ground to fit the bore in its cylinder fluidtight. Although this arrangement is preferred, yet we may use a piston and pistoncylinder not ground true and provide a packed piston. On the other hand, instead of the pressure-chamber cs between the casing C and delivery-cone C3 in communication with the interior of the latter, it is obvious that the piston cylinder may be formed on or placed in communication with the delivery branch, as will be readily understood.

In order to prevent the iiap c2 of the combining-cone C2 from flying open or being partially opened by an abnormal rush of steam into the injector, we provide a piston P', similar to piston P, working in the bore of a projection o9 on casing C, said bore being likewise in communication with the aforesaid annular chamber e8 between said casing and the delivery-cone C3, said piston P' controlling a plunger P2 through a lever L', similar to lever L, and said plunger P2 acts upon the ilap c2 of nozzle C2 in the same manner as the lever L acts upon the stem of valve V' and under similar conditions of pressure.

In the application of our invention, in so far as it relates to the overflow-valve, to a combined exhaust and supplementary live steam injector (shown in Figs. 2 and 3) the same symbols oi reference indicate like parts, the casing C for both injectors being made in one casting, the delivery-cone C3 being normally closed by a spring-actuated checkvalve o. The live-steam pipe p for the supplementary injector communicates with the live-steam cone C, C21 indicating the ap combining-cone and C31 the delivery-cone. The overflow-valve V' for the supplementary injector is hung from one end of the short arm of a lever L, while the controlling-piston P is hung from the longer arm of said lever and works in the bore of a branch c71 in communication with an annular chamber es between the casing C and the delivery-cone CN for precisely the same purposes as above de scribed. In the delivery-pipe p of the supplementary injector there is a valve-chamber for a ball check-valve fu', the lift of which is limited by a suitable abutment a.

The overflow branch c4 for the exhauststeam injector (shown partly in full lines and partly in dotted lines in Fig. 2 and in full lines in Fig. 3) has a suitably-loaded check iap-valve v2 to prevent access of air to the overiow-chamber ci.

The combined iluids from the exhauststeam injector pass from the delivery-cone C3 through passages 192 292 in the casing C, Fig. 3, which passages lead to a passage p', Fig. 2, in communication with the receiving end of the iiap combining-cone C21 of thev supplementary live-steam injector.

With the exception of the appliances for controlling the overflow-valve the combined exhaust and supplementary live steam injector is also of a Well-known construction.

. The live-steam nozzle c5 for the exhauststeam injector is arranged axially in a flanged part 021, interposed between the exhaust-pipe and the anged exhaust-steam inlet of the injector, live steam being admitted through a passage p3 in an axial bearing b for said live-steam nozzle c5. The exhaust-steam cone C' is adjustable toward 'and from the iap combining-cone C2 of the exhaust-steam injector by means such as hereinabove described in respect of the like cone of the injector shown in Fig. l. Obviously the overliow branch for the supplementary live-steam injector may be connected with the like branchfor the exhaust-steam injector.

Having thus described our invention, what we claim as new therein, and desire to secure by Letters Patent, is

IOO

IIO

l. In an injector, the combination with the overflow-valve and the delivery-cone, of a piston-cylinder in communication with the interior of said cone, a piston in said cylinder, and a rock-lever acted upon by the rod-of said piston and acting upon the stem of the overiiow-Valve, for the purpose set forth.

2. In an injector provided witha fiap combining-cone, means iniiuenced by Working pressure in the injector and operating to hold the iap of said cone to its seat, for the purpose set forth.

3. In a combined exhaust and supplementary live steam injector, the combination with the overliow-Valve of the supplementary injector and its delivery-cone; of a piston-cylinder in communication with the interior of said cone, a piston in said cylinder, and a rock-lever acted upon by the rod of said piston andacting upon the stem of the overowvalve, for thepurpose set forth.

4E. In an injector, the combination with the casing', the overflow branch and valve,the delivery-cone and an annular chamber between said casing and cone in communication with theinterior of the latter; of a piston-cylinder opening into said chamber, a piston in said cylinder and a lever operated by the piston and acting upon the stem of the overflowvalve, for the purpose set forth.

5. In an injectorprovided with a flap combining-cone, the combination with the casing,

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