US268353A - High steam and low watee detector - Google Patents

Description

2 Sheets-Sheet 1. R.'D. BARR.

EIGE STEAM AND LOW WATER DETECTOR.

Patented Nov 28, 1882.

(No Model.) 2 sheets-sheet 2.

Y R. D. BARR.

n HIGH STEAM AND LOW WATER DETECTOR. No. 268,353. Patented Nov. 28, 1882.

Wilmesses wenjr loY UNITED STATES PATENT OFFICE..

ROBERT BARE, OF PITTSBURG, PA., ASSIGNOR OF TWO-THIRDS TO VILLIAM STARKEY AND THOMAS W. DAVIS, OF SAME PLACE.

HIGH-STEAM AND LOW-WATER DETECTOR.

SPECIFICATION forming part of Letters Patent No. 268,353, dated November 28, 1882.

Application filed Af lpiil 1o, 1882. (No model.)

To all whom it may concern Be it known that I, ROBERT D. BARR, of Pittsburg, in the county ot' Allegheny' and State of Pennsylvania, have invented a new and useful Improvement ill High-Steam and Low-VVater Detector, and I do hereby declare the following to be afull, clear, and exact description thereof, reference being had to the accompanying drawings, forming part ot' this specification, in Which- Figure l is a side elevation thereof. Fig. 2 is a top view, partlyin section, through line a: x of Fig. 1. Fig. 3 is a vertical section through the valve-chamber. Fig. 4 is a side elevation of a modification of my device. Fig. 5 is a horizontal section through w a: of Fig. 4.

In the several figures like letters ot' reference indicate the same parts.

Myinvelltion relates to self-actin g detectors, to sound an alarnl whenever the waterin the boiler gets too low, and also whenever the pressure of steam in the boiler rises above that for which the apparatus is set, which are operated through theinstrumentality ofthe expansion of a metallic tube into which live steam is permitted to enter whenever the Water in the boiler falls below a given level. In order to secure the requisite degree of motion of the alarm apparatus by the direct action of the elongation of such a tube from the dierence between the heat of the water in the boiler and the live steam, an expansiontube ot' conslderable length would ordinarily be required. In order to avoid this necessity and to permit of the use of a short expansiontube, and thereby secure greater compactness of construction and efficiency ot' operation in the apparatus, and lessen its liability to accidental injury or deraugement, I actuate the Vvalvestem of the steam-whistle by nleans ofa lever having its fulcrum at the extremity of its short arm, and the power applied between the ful` crum and the valve to be operated interposed between the expansion-ribs and the valve of the steam-whistle, so that the short arm of such lever is operated by the former, while the long arm actuates the latter, whereby a comparatively slight elongation ot' the expansion-tube will eft'ect a considerable motion of the valve-stem. The arrangement of the lever D so that its point of connection with the ex pansion-tube shall be intermediate between its fulcrum and the valve-stem is designed to obviate a serious diiilculty which I have. found to exist in the use ot" a lever of the first order, by causing the strain on the expausiontube to be exerted in a plane coincident, or very nearly so, with the axis ot' the expansion-tube, and thereby preventing the expansion-tube being bent or drawn downward, which would materially detract from the eficiency of the apparatus, the extremity of the long arm of the lever operating to raise the valve on the elongation of the expansion-tube, but not being attached to the valve, which is thus left free to rise against the pressure of a weight or spring, so as to sound the whistle whenever the pressure of steam in the boiler becomes excessive. This effect is also increased by constructing the connection between the free end of the expansion-tube and the lever of a metal having less expansibility than that of which the pipe is made.

In the drawings, A is an expansion-tube, made of brass or other metal having a higher rate of expansion than iron.

B is a short connecting-pipe, to which the tubular downward extension E' of the valvechamber E is firmly secured by bolts or screws a ill the manner shown in Fig. 5. The expansion-tube A is screwed into the tubular piece E', thus connecting directly with the pipe B.

The pipe B may be of iron, andisscrewedinto y olle ot' the gage-cock openings in the head of the boiler by lneans ot' a right-and-left screw coupling, b, so that the whole detector apparatus may be removed and replaced without turlling it on its axis. The counectng-pipeB may be so constructed, as shown in Fig. 1, that the expansion -tube A shall project horizontally from the head of the boiler in aline with the axis of the steamsboiler, or, as shown in Fig. 5, so that the expansion-tube A may be at right angles to the axis ofthe steam-boiler, as may be most convenient. In the connecting-pipe B is a valve, c, Fig. 5, which, when closed, shuts ott' the steam or water connection between the boiler and the expansion-tube A when desired, the valve c being operated byahand-wheel, d. As the pipe B opens into the boiler just below ICO the ordinary water-line the water from the boiler tills the expansion-tube A whenever the water in the boiler is at or above the proper water-level; Should the water in the boiler become too low, the water-level falls below the top ot the eriee ofthe pipe B and live steam from the boiler enters and fills the tube A, driving the water from tube A back into the boiler.

A gage-cock, C, Fig. 1, at the outer extremity of tube A, serves as and may take the place of one ofthe ordinary gage-cocks of the boiler, and may be used as such. The introduction of a gage-cock, G, at the outer end ofthe horizontal expansion tube A not only permits Vof the substitution of my apparatus lfor one ofthe ordinary gage-cocks, but also prevents the clogging ofthe expansion-tube with froth or sediment, which are removed from the interior ofthe expansion-tube every time that the gagecock C is opened. This is veryimportant, because otherwise the interior of the expansiontubewould hecomecoated with sediment,which, being a bad conductor of heat, would soon impair and ultimately destroy the efficiency of the apparatus by preventing the requisite degree ot' expansion of the tube A. The gagecoek U, placed at the outer extremity ofthe expansion-tube A, besides performing the functions just stated, affords a ready means oftesting at any time whether the apparatus is in good working order. When the water in the boiler is at the proper height above the top of the pipe B. and the expansion-tube is consequently tilled with water, it is only necessary to open the cock C for a sufcient length of time toallowY the comparatively cool water which it contained to run outthrough theventpipef, when its place will be immediately supplied by water directly from the boiler, which, being much hot-ter than the water with which the expansion-tube A is ordinarily tilled7 will cause it to expand and elongate, raising the valve and sounding the whistle, if the apparatus is in good working order, in the same way as if steam were admitted to the expansiontube. When the cock C is turned merely to test the height of the water in the boiler it need not be left open long enough to sound the whistle. As an apparatus of this description operates automatically only in case of danger from too high steam or too low water, it isliable to become clogged from disuse. Hence the importance of a ready means ot testing its condition, such as is afforded by the gage-cock C.

When the water is at such a height in the boiler that the tube A is filled with water the pipe is exposed to a temperature of about 1400 Fahrenheit; but if the water in the boiler falls so low as to admit steam into tube A, itis then exposed to a very much higher heat, so that the tube A expands longitudinally as soon as steam is thus admitted, and it is by this elongation of the expansion-tube A that the detectingapparatus operates to indicate and give warning ot' the fact that the water is too low in the steam-boiler. In order to secure sutficient elongation ot' the expansion-tube A to operate the apparatus it should be made of brass and be from seven to ten inches in length.

A cap, e, is screwed onto the outer extremity of tube A, in which is placed the valve-seat ot' the gage-cock G, and from which a vent-pipe, f, allows the passage ot' water or steam from the tube A, as the case may be, thus indicating the height of water in the boiler.

To a collar, c', on the cap e are pivoted two arms, g g, made of iron or steel, one on each.

side of tube A, the other extremity of these arms being pivoted to a lever, D, which lever has its fnlcrum at h on a forked bracket, I, which is attached to, or is cast as a part of, the valve-chamber connecting with it both above and below the expansion-tube A, as seen in Fig. l. The forward extremity of the bracket I isan annulus, through which the tube A passes, and by which it is sustained and supported. The arms g g, being of iron, do not lengthen by heat as much as the tube A, and when the tube A elongates by expansion from the additional heat to which it is exposed when steam enters it the arms g g, being pivotcd above the fulcrum /1J of the lever D, cause the rear or free end of Athe lever D to rise. The effect of the raising ot' the free end of the lever D is to raise the stein of a valve in the valve-chamber E, which admits steam to pass to the steam-whistle W. This will be better understood by reference to Fig. 3, which represents a vertical section ot' the valve-chamber and its connections. In the valve-chamber are two steamways, s s. one above the other. A pipe, p, from this steam-boiler (see Fig. 1)con ducts live steamY to the lower steamway, s.Y A valve, o, is seated in the steam-chamber in the partition separating the two steam ways s s from each other. The stem tof the valve e extends from the valve-chamber E upward and IOO passes through a crotch, i, in the free end of 11o the lever D, (seen in Fig. 2,) so as to be raised as the long arm of the lever is raised. When the expansiontube is cooled and contracts by the reduction of heat when the wateris raised in the boiler above the level of the top of the tube B, the long arm ot the lever D falls and the valve is closed by the lever H and weightK or spring. The valve-stem t,not being attached to the lever D,is free to rise without movingthe lever D whenever the steam-pressure under the valve becomes excessive, as hereinafter explained. When the valve@ is raised, live steam passes from steam-pipe p through the lower steam way s, and th rough the valve-seat into the upper steam way, s', and thence passes without obstruction through pipe gto the steam-whistle, thus sounding the alarm and indicating -the fact that the water in the boiler has gotten so low as to admit steam into tube A. On the stem t of the valve o is a nut, n, screwed onto the valve-stem above the crotch of the lever D, so that by setting the nut u up or down on the valve-stem t the valve U may be setto open more or less, as may be desired. Opposite to IIS l A. r

-valve-stem t.

the point p in the lower steamway, s, at which the'steam-pipe enters the steam-chamber E, is au orifice, 7c, (Figs. 4 and 5,) to which is attached a pipe and cock, j, by means of which the steam-pipe p and steam-chamber E'may be relieved of any Water which may collect there from the condensation of steam. A bracket, Gr, is attached to the pipe q, (leading to the steam-whistle,) to which bracket is pivoted a lever, H, having a sliding weight, K.

The lever H extends directly over the top of the stem tof the valve c, and rests upon the valve-stem near to the fulcrum of the lever, by which means the valve is prevented from being raised by steam-pressure applied to its under surface, unless that pressure exceeds that at which the lever H is adjusted to rise by means of the weight K.

When the apparatus is in loperation steam is allowed to pass freely through the pipe p into the lower steam way, s, in the valve-chamber E,and in case the steam-pressure becomes excessive the valvev is raised,and steam passing, as before described, through the upper steamway, s', to the whistle, causes the alarm to be sounded. It will be noticed that when the whistle is sounded,in consequence ot' excessive pressure of steam in the boiler, the valve e is raised entirely independently of the lever D. It is obvious that the weightK may be set on the lever H'so as to allow the alarmwhistle to be sounded whenever the steampressure in the boiler exceeds the number of pounds to which the lever is weighted, as in ease of va safety-valve. v As a modification of the apparatus, an adjustable spiral spring may he substituted for the lever H and weight K. This modication is shown in Fig. 4. The upper end of the valvestem t ot' the valve c is enlarged in diameter, and is bored withV a screw-thread for a short distance downward to receive the end of a screw-rod, t', which forms an extension of the The upper end of this extensionpiece t plays through a bracket, w, which is adjustably attached to the steam-pipe q by a collar on the bracket and a set-screw, o, as shown in Fig/1. Around the top of the valve- 'stem t is a collar, 1', between which and the bracket w is placed a spiral spring, m, which surrounds the extension-piece t of the valvestem. This spiral spring x performs the same function as the lever and Weight before described, and the downward pressure of the spring on the valve may be regulated by adjusting the height of the bracket w by means of the set-screws o.

In order to communicate intelligence to any part of a building or factory where steam power is employed, or to any part ot' a steamboat,whenever the water in the boiler falls be-A low a safe water-level, I connect an electrical alarm apparatus tothe devices which I have described, as shown in Fig. 1. From one side of the crotch of the lever D a small horizontal plate, y, projects. Above the plate g/ is placed a brass rod, z, having a platinum point projecting toward the plate y, so that whenever the lever D is raised electrical Contact may be formed between the rod z and the plate y. The rodez is insulated from the apparatus in any convenient and usual manner. A wire from one pole of an electric battery is vconnected with the insulated rod e, and the wire from the other pole is connected with the apparatus, as at z', Fig. l. Whenever, therefore, the electrical circuit is closed by contact between the plate y and the insulated rod z, the electrical bell is rung at any point where such bell may be placed. A

If it is desired to sound the electric b ell whenever the whistle is blown to indicate either excessive steam-pressure or low water in the boiler, the insulated rod z may be so placed as to come in contact with the valve'- stem t, whenever it is raised either by the lever D or by pressure of steam on the valve c. i I do not in this application make any claim to the operation of an electric alarm by means of an expansion-tube for calling attention to an excessive pressure of steam or to a lack of water in the boiler, as that forms the subjectmatter Vof another application for ay patent made by me; but,

Having thus described my improvement, what I claim as my invention, and desire to secure by Letters Patent, is-

1. As an apparatus for indicating either high steam or low water in steam-generators, the combination of the expansion-tube A, gagecock C, lever D, valve t, adjusting-nut 1t, and Weighted lever H, with a steam-whistle, W, and connecting-pipe p. constructed and arranged substantially as described.

`2. The arrangement of leverD parallel with the horizontal expansion-tube, having its fulcrum at a point out-side the plane of the axis of the tube and pivotally connected with the tube in or near the plane of its axis and on both sides thereof,whereby the expansion-tube may support the other parts of the apparatus without liability to derangement arising from any straining ofthe steam-joints, substantially as and for the purpose specified.

3. The combination, with expansion-tube A, of the bracket I, adapted to support the expansion-tube, lever D, arranged parallel with the expansion-tube and fnlcrumed at one extremity on the bracket at a point outside the plane of the axis ofthe tube, linksor arms gg, pivotally connected with the lever D, and with the expansion-tube ata point in or near the IOO IIO

IZO

plane ofits axis, a valve operated by the free `ROBERT D. BARR.

Witnesses:

T. B. KEER, J. K. SMITH.

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