US16054A - Wateb-gage foe steam-boilers - Google Patents

Description

J. C. HARRIS. Water Gage.

No. 16,054. Patented Nov. 11. 1856.

UNITED STATES PATENT OFFICE.-

JOHN C. HARRIS, OF SAVANNAH, GEORGIA.

WATER-GAGE FOR STEAM-BOILERS.

Specification of Letters Patent No. 16,054, dated. November 11, 1856.

in which a side elevation of a gage containing my improvement is represented, to-

gether with a fragment of the end of a steam-boiler with which the gage is connected.

The float water gages heretofore in use in steam-boilers give very inaccurate indications of the height of the water, especially in those boilers in which salt or muddy water is used, as an increase of the density of the water, due to a concentration of the mud or saline matter which it holds in solution or suspension, would, without any in crease in the height of the water, raise the float, which would thus give a false indication and show a higher level of water within the boiler than actually existed, indeed, the level of the water might even fall, and yet, if its specific gravity were much increased, the float might indicate a rising instead of falling of the water level.

To avoid this difficulty and make a float gage indicate with practical accuracy the varying height of water within a steam boiler irrespective of its varying density, is one of the main objects of my invent-ion, which consists in so constructing the gage that I can employ very light media, such as oil for example, within the gage chamber to float upon the water and carry the float of the gage. As the density of even pure water is greater than that of the oil and the stratum of oil is comparatively shallow, any variation that occurs in the density of the water in a boiler will produce comparatively little change in the level of the oil, and thus the gage-float will be buoyed up on a medium that will raise and lower it more nearly in proportion to the rise and fall of the level of the water in the boiler than if the float rested directly upon the water whose density varies so much.

A gage-float to work properly in a thin stratum of oil interposed between it and the water must be of far smaller dimensions than could be safely used if it were to float directly upon the water, because from the tendency of the earthy and saline matter contained in the water to be deposited upon the float if it were small and possessed little buoyant power the accuracy of its indications would be destroyed very speedily, and, as a necessary consequence, would be rendered useless.

In my improved gage the oil insulates the float from the water and consequently protects it from earthy or saline incrustations leaving it as sensitive and its indications as accurate after it has been long in use as when new, whereas the gages whose floats are upon the water must be large, in order that their sensitiveness may not be materially impaired by a slight accretion of earthy and other matter upon them, but in all cases these floats are constantly deteriorating by such accretions and at length become so much loaded by them as to be useless.

In the accompanying drawing a fragment of a steam boiler is shown with one of my improved water gages attached thereto, a being the water-leg of the boiler, b the steam chamber above the water, (Z the water level within the boiler and 0 the upper flue.

K is the float chamber of the gage to contain the oil for carrying the float and may be of the usual form of water float chambers or of any other convenient form, but it need not be more than half as large as the chambers for a water float would require to be made. The lower part of this chamber is connected by a pipe with the water space of the boiler, and its upper part is connected by a pipe (P) with the steam space of the boiler to allow the water and steam to flow freely into the float chamber, the middle of which should be on a level with the line of average water-level in the boiler. As sediment will constantly settle in the pipes of the gage, it is frequently necessary to discharge it, and in the ordinary water gage this is done by simply opening a cock at the bottom of the water pipe, but in my improved gage this operation would blow out the oil, which would have to be replaced at considerable expense. To avoid this expense I fit the upper part of the water-pipe with a stop cock which should be closed before opening the bottom cock to blow out the pipe. By this means the sediment can be blown out as often as required without wasting the oil. The lower part of the pipe j has a bend in it which extends below the level of the orifice through which it connects with the water space of the boiler. The purpose of this bend is to prevent steam from passing from the "boiler into the gage which would cause it to foam and disturb the float. The part of the Water-pipe which leads directly from the orifice in the side of the water space of the boiler is fitted loosely with a cylindrical plug of wood (f) which, by virtue of its slow conduction of heat,-tends, it is supposed, to prevent steam from passing from the boiler into the gage, but this effect may result from the plug occupying the center of the pipe, and thereby compelling any steam that enters the pipe to pass through the thin stratum of water in the annular space (s) that surrounds the plug, in contact with the sides or" the pipe, which, being exposed to the atmosphere, will be comparatively cool, and the steam flowing in contact with it can scarcely escape condensation and the consequent loss of its power to produce foam. This wooden plug has a metallic stem (7:) attached to it, which passes throu 'h a stuflfing-box to the outside of the pipe. This stem is for the purpose of being taken hold of, to work the plug back and forth in the pipe to agitate any sediment that may be deposited therein, and thereby facilitate its discharge when the water pipe is blown out. The steam pipe (P) is also provided with a stop cock and the steam space in the float-chamber is provided with a bloW-ofl cock (0). By means of these cocks the steam pipe and float chamber can be blown out at pleasure.

The float (m) is provided with a stem (n) which passes through a stuifing-box in the top of the chamber and terminates, at its upper end, in a finger which is arranged to work up and down over a graduated scale that indicates the level of the water, in inches, above or below the line of mean level.

The oil is kept fresh and limpid by the constant streams and drops of hot water running down through it from the pipes above, where it is produced by the condensation of steam.

' Having thus described my improvement inwater gages for steam boilers, what I claim therein as new, and desire to secure by Letters Patent is The arrangement of the float-chamber, the stop-cocks and the blow-oiif cocks, to adapt the gage to the employment of oil, interposed between the float and the water, to parry the float, substantially as herein set orth,

J NO. G. HARRIS.

Witnesses:

THOMAS D. Bron, P. N. RAYNAL.

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