US1364287A - Low-water alarm for steam-boilers - Google Patents

Description

J. A. LEAVITT.

LOW WATER ALARM FOR STEAM BOILERS.

APPLICATION FILED JAN. 13. 1920.

l Invenor James Leavitt JAI'IES ALLEN LEAVITT, 0F HERMOSA. BEACH, CALIFORNIA.

LGW'".UATER ALARM FOR STEAM-BOILEES.

Speetcation of Letters IEatent. i

Patented Jan. at, 1921.

Application filed January 13, 1920. Serial No. 351,15e.

T 0 @ZZ whom it may concer/a Be it lnown that l, latins A. LnAvrr'r, a citizen of the United States, residing at Hermosa Beach, in the county of Los Angeles and State of California, have invented certain new and useful improvements in Low-Vlater Alarms for Steam-Boilers; and l 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 the letters and figures of reference marked thereon, which form a part of this specification.

This invention relates to new and useful improvements in low water alarm apparatus for steam boilers, and comprises means whereby, when the water within the boiler lowers to a dangerous point, means is actuated for automatically sounding an alarm and shutting off the supply of fuel leading to the burners of the boiler.

rl`he invention, more particularly consists of a plug mounted in an opening of the crown sheet of a boiler, containing a fusible material, against which a spring pressed rod bears which, when the tempera-ture of the boiler is sufficient to cause the metal to fuse, will be actuated to remove any scale which might prevent the fusible metal from opening passageways through which steam is adapted to pass, for the purpose of sounding the signal and shutting ofi the supply of fuel to the burners.

My invention comprises various other details of construction, combination and arrangement of parts which will be hereinafter fully described, shown in the accompanying drawings and then specifically defined in the appended claim.

lf illustrate my invention inthe accompanying drawings which, with the letters of reference marked thereon, form a part of this application, and in which:

Figure l is a central vertical sectional view through a portion of the boiler, showing the application of my invention thereto.

Fig. 2 is an enlarged detail sectional view through the fusible plug, pipe and connections therewith, and illustrating in elevation a spring actuated plunger for removing any scale which might form over the lower surlface of the top section of the fusible plug, anc

Fig. 3 is an enlarged detail in section of a steam 'actuated valve.

Reference now being had to the details of the drawings by letter:

il, designates a steam boiler, and B a crown sheet therein. A plug N is mounted in a threaded opening in the crown sheet, and M designates a pipe having threaded connection with an aperture in the top of the plug, and extending upward and passing through an opening in the top of the boiler. 'A slight distance above the top of the boiler said pipe is connected to a cage C with which it has threaded connection. Said plug is provided with a series of circumferential openings O and in the opening in said plug intermediate the lower end of the pipe M and the upper marginal edge of said openings O is a filling of fusible material P.

Said plug has a central opening Q leading downward from a location opposite the lower marginal edges of the openings O and connects with branching ducts Q2 leading through the extreme lower end of the plug, and which opening and branching ducts are adapted to be filled with a fusible material Q3.

A rod L is positioned within the pipe M and has a pointed end L resting against the upper surface of said fusible filling P. and its upper end is provided with a shoulder K against which the lower end of a coiled spring d bears, its upper end lbeing engaged by a disk H engaged by an adjusting screw F, mounted in the cap Gr which has threaded connection with the cage C. A pipe D is connected to and communicates with the interior of the cage C, and E is a whistle which is connected to the pipe D at any suitable location, and which pipe communicates with a casing S', which in turn is connected to a valve casing R containing a valve T, the stem of which is connected to a follower S, against which a spring S2 bears, and tends to normally hold the valve raised from its seat.

A pipe U communicates between the valve casing R and the burner V.

ln operation, when the apparatus is adjusted for use, the parts assume the position shown in Fig. 2 of the drawings, in which which closes communication between the interior of the boiler and the pipe M, the valve T being unseated to permit oil to flow to the burner, whereby heat may be generated by the burning of fuel to produce steam within the boiler. In the event of the water in the boiler lowering to a dangerous point, and when the temperature therein increases sufficiently to fuse the filling material P of fusible metal in the plug N, and upon which the point of the rod L rests, the metal, as it fuses, will run through the openings O in the plug and communication will be afforded between the boiler and the interior of the pipe M, and the steam passing through the pipes M and D will cause the whistle E to be sounded and the valve T to seat, which latter operation will shut off the supply of oil to the burner V.

In the event of any scale forming on the lower surface of the fusible filling material P, the pointed end L of the rod will break the same as the spring J, which is normally under tension, will force said rod downward, removing the scale and permitting the y free passage of the steam into the pipe if. As the fusible material in the openingand the ducts in the lower portion of the plug melts, it will run through the ducts to the furnace beneath, and allow steam and water to flow from boiler to lire-box.

crown sheet, a plug mounted in an opening in the crown sheet and having circumferential openings therein and also downward extending openings in the lower part thereof and communicating with the fire box, a filler of fusible material in the upper end of the plug which communicates with said circumferential openings, fusible material filling said downward extending openings, a pipe connected to said plug and passing through an opening in the boiler, a cage connected to the top of said pipe, a rod mounted within said pipe and having its lower end pointed and adapted to rest upon the upper surface of the fusible material in the upper portion of said plug, said rod having a shoulder near its upper end, a screw actuated disk mounted in said cage, a coiled spring interposed between said shoulder and disk, a pipe leading from said cage and provided with a whistle, a fuel pipe disposed beneath the lower end of said pipe which leads from the cage, and a normally open valve in said fuel pipe, closable by pressure of steam when admitted to said pipe leading from the cage. l

In testimony whereof I hereunto aflix my signature.

JAMES ALLEN LEAVITT.

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