US1561135A - Low-water alarm for boilers - Google Patents

Description

Nov. 10, 1925.

W. M A. BARBOUR LOW WATER ALARM FOR som'sns Filed April 16. 1924 IN VENTOR WITNESSES A TTORNEYS Patented Nov. 10, 1925.

NITE D S TA WILLIAM MAGALLASIER. BARBOUR, OF BOANOKE, VIRGINIA.

LOW-WATER ALARM FOR BOILERS.

Application filed" April 16, 1924. Serial No. 707,011.

To allwhom it may concern- .1

Be it known that I, Tr-Lemar M. Bnnnorm, a citizen of the United States, residing at Roanoke, in the county of Roanoke, State of Virginia, have invented certain new and useful Improvements in Low-VVa.ter Alarms for Boilers, of. which the following is a specification.

My invention is a low water alarm for steam. boilers, and it consists inthe com-bi.- natirons, constructions, and arrangements herein described and claimed.

An object of the invention is to provide a simple and reliable device which is adapted for attachment to a steam boiler of substantially conventional construction and which is adapted to be actuated when the water within the boiler falls to a definite level to give an audiblesignal.

A further object of the invention is to provide an attachmentof the character described which willnot interfere with the op oration of the boiler to which it is applied in an ordinary manner and which is thoroughly practical commercially.

Other objects and advantages will be apparent from the following description, considered in conjunction with the accompanying drawings, in which Figure 1 is a longitudinal section: through a portion of a steam boiler and through an attachment embodying the invention with which the boiler is equipped,

Figure 2 is a plan view of the attachment with the signal alarm thereof omitted,

Figure 3' is a transverse vertical section through a portion of the upper wall of the boiler and through the attachment, the view being taken. substantially on the line 33 of Figure 1, with the signal alarm. omitted,

Figure 4 is a perspective view showing a valve and valve stem construction which is comprised in the device, and

Figure 5 is a relatively enlarged section along the line 55 of Figure 4.

In Figure 1, the numeral 1 designates a steam boiler generally. Only a portion of the boiler is shown. As is usual, the boiler is provided with a water chamber 2 which extends below the level of the crown sheet 3 for the fire-box 4- of the boiler. It, of course, is desirable that means be provided for apprising an interested person that the level of water within the chamber 2 of the boiler is relatively low since otherwise the continued operation of the boiler without an additional quantity of water being supplied thereto may result in injury to the-boiler and to the structure adjacent thereto. My invention contemplates the: provision of means which will act automatically when the water within the boiler falls to a definite level to sound an audible alarm.

In carrying out my invention, I provide a box-like casing 5 which is supported upon the boiler top and which defines a chamber 6. The chamber 6 has communication with the water chamber 2' of the boiler through a drain pipe 7 which opens at its upper end through the bottom of the casing 5 and depends within the water chamber 2 below the level of the crown sheet 3. The chamber 6 also has communication with the chamber 2 through a pipe 8 which extends vertically through the bottom of the casingand terminates at its upper end; adjacent to but short of the top wall of the casing 5. The pipe 8 depends within the water chamber 2 and terminates at its lower end at a slight distance above the level of the crownsheet 3.

The chamber 6 serves as a. float chamber. A float 9 is supported: therein by being at tached pivotallyto one end, of a float lever 10 which is pivotally supported at its other end on a horizontal pivot element 11 which is carried by lugs 12 depending from: the top of the casing 5 adjacent to one end of the latter. The float 9 thus is adapted to move vertically within the chamber 6" in accordance with the rise and fall of liquid therein. A vertical guide 13 depend-s from the top'of the casing 55- and has a vertical slot 14 in which the floatarm 10 may move, the engagement of the guide 13 with the float arm being adjacent to the free end of the latter.

The top of the casing 5 is provided with a threaded opening 15 in which is screwed the lower end portion of a tubular valve casing 16. The bore of the valve casing 16 is reduced in diameter adjacent to its lower end, as at 17, to rather closely engage with a longitudinally slotted valve stem 18 which extends slidably therethrough. The portion of the valve casing that is reduced in inner diameter is fashioned at its lower end, as at 19, to provide a seat for a downwardly opening tapering valve disc 20. The stem 18 extends through the bor of a tubular boss 21 which is upstanding from the valve casing and the upper end portion of the valve stem carries a nut 22 which is in threaded engagement therewith. An expansion spring 23 is arranged on the tubular boss 21'be- 'ward until the valve has been moved against the seat therefor and to position to prevent flow of fluid from the chamber 6 into the valve chamber 16.. I i

I The valve 20 has apendent axial extension 24 which is enlarged and fashioned in loop format the lower end thereof, as indicated at 25., The float arm 10 extends through V V 16 to'the whistle'28 and W111 cause the latter 5 the loop and engageswith the lower "end of the latter 111 such manner as to force the valve 20 downward and away fronrjits seat when the float 9 is in lowered position, as illustrated in Figure 1. r

. The valve casing 16 is provided"with a tubular lateral'outlet 26 adapted for connection with the-conduit 27leading to a whistle28 or other suitable signal of known type of construction and adapted to bef actuated when pressure fluid is supplied thereto. i

A by-pass conduit 29 may connect the upper part of the float chamber 6 with the upper part of the water chamber 2 0 1 the boiler and may be provided with a valve 30 of ordinary construction. i

l I threaded plugs,fas indicated at 81.

From the foregoing description of the various parts of the device, the operation thereof Wlll bereadily understood; Let us assume that the water chamber 2 of the end of the pipe 8 andthe valve 30 isclosed; The steam pressureVwithin the boiler will have caused water to rise through the pipes boiler isfilled to a level above 'theflower 7 and Sand to flow=into the float chamber depends from the valve 20 so that the spring; 23 will bepermittedto function to return the valve 20to closed position."'VVhenthe level of the water within the chamber? falls below th -lower end of the pipe 8, the

pressure fluid from the boiler will pass through the pipe 8 into the' float chamber and the, pressure within the float chamber and the boiler will be equalized and, therefore, water will be drained from the chamwater level within th float chamber, thereby causing movement of the valve 20 from its seat; The pressure fluid Within the float 6,-then will escape through the valve casing to be actuated, whereby an audible signal will be given. I r 1 Obviously, my invention is susceptibleof embodiment in forms other thanthat which is'illustrated in the accompanying drawings, and I, therefore, consider as my own all modifications and adaptations that fairly fall Within the scope of the appended claim.'

The by-pass 29 and valve 30 are provided to facilitate the testing of the device.

The combination with a boiler, of a casing superimposed-on the boiler, said casing having an outlet adapted for connection with a whistle, a downwardly opening valve controlling said outlet and spring-pressed toward closed position, a float, means adapted to be actuated on downward movement of said float to move said valve from closed posltlon, a pipe establishing"communication between the water chamber of the boiler an-dthe interior of said casing, said pipe terminating at its upper end ata considerable distance above the level of the bottom of the casing and terminating at'its lower end slightly abov the'level of the crown sheet of the boiler, a second pipe opening at its upper end through the bottom of the casing and depending within the water chamber to terminate at its lower end below the level of the crown sheet of the boiler. and a valved by-pass conduit connecting the upper part of said casing with the upper part of said boiler. p j

I WILLIAM MacALLASTER HARBOUR.

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