US1416809A - Superheater - Google Patents

Description

E. H. FOSTER. SUPERH'EATER. APPLICATION FILED NOV-14', 191's.

Patented May 23, 1922?.-

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. fwemfor; W 2% a/I7 TTUE If" the ERNEST H. FOSTER, 0F DONGAN HILLS, NEVI YORK, ASfiIG-NOB; TO FOWER SPECIALTY COMPANY, OF NEW YORK,

A CORPORATION CF NEW YORK.

SUIPERHEATER.

Application filed November 14, 1919.

To all whom it may come/"1t:

Be it known that I, Emvns'r H. Fos'rnn, a citizen of the United States of America, residing at Dongan Hills, Richmond County, and State of New York, have invented certain new and useful Improvements in Superheaters, of which the following is a full, clear, and exact description.

In a patent which I obtained in July 9, 1918, No. 1,272,248, a superheater for steam boilers is shown as located in the combustion chamber at the rear of a return flue tubular boiler, and this arrangement is typical of a class of boilers in which substantially similar conditions obtain.

To this arrangement certain well defined objections lie. The supporting means for the superheater are expensive; the superheater occupies valuable space in the rear of the boiler and thereby presents ready access to the boiler tubes for inspection and repair; it is somewhatdiflicult to control the amount of superheat which involves cutting out of superheat surface which is an expensive operation; there is apt to be interference with the usual piping arrangement of the boiler blow-oil, and there is a certain amount of interference with the flow of the gases through the rear passage which can only be avoided by increasing the depth of the chamber or space at the rear of the boiler.

Generally speaking, therefore, the association with boilers of this type of superheaters is an engineering problem which, for its accomplishment in an economical and eflicient manner is by no means easy of solution. Working on such problem I have devised a plan which overcomes the objections heretofore noted and which secures certain very marked and important advantages.

According to this, my invention, I place the superheater for boilers of this type under the rear portion of the shell. of the boiler and back of the bridge-wall arranging the superheater elements in horizontal rows, and

so arranged that a portion of the gases from the fire after having been exposed to the cooling effect of the boiler shell, are forced or are caused to pass over and sweep the superheater tubes.

By this disposition, I am not only enabled to use much simpler and cheaper supports for the superheater, but I may regulate the amount of superheat readily and perfectly Specification of Letters Patent.

Patented May 23, 1922.

Serial at. 337,955.

by the use of a heat resisting slab or plate which may be moved more or less over the supelheater and thus control the volume of hot gases'which pass over its tubes.

This in'iprovement is illustrated in the accompanying drawings in which Fig. 1 is a view in elevation of the rear of a return tubular boiler equipped with a superheater in the manner above set forth, the setting being shown in section; and

Fig. 2 is a vertical section on the line AA of Fig. 1.

The numeral 1 indicates a typical form of return tube boiler, 2 is the setting and 3 is the bridge-wall common in this class of furnace. The superheater, the tubes of which are designated by the numeral 1, is mounted on supports 8 and 9 back of the bridge-wall and under the rear portion of the boiler 1.

The superheater tubes are supported horizontally and are connected in the usual manner to headers 12, and are connected at one end by a steam inlet pipe 5 from the boiler and at the other end by an outlet pipe 6 to the steam main.

Substantially on a. level with the top of the bridge-wall 3 is a slab of infusible material 7, which is movable over the superheater to a desired extent and which may be adjusted to project more or less into the path of the gases, the direction of which is shown by the arrows 18, and thus regulate the volume of such gases that sweep the superheater tubes.

In all other respects the construction follows well known lines. The boiler is supported by brackets 10 resting on ledges in the setting 2, and in the rear wall of the setting is the usual access door to the combustion chamber.

The hot gases from the grate sweep first the boiler surface and then enter the chamher at the rear. After rounding the rear edge of the slab 7, they pass in part downward and over the superheater tubes and thence upward to the rear of the boiler and then. through the boiler tubes. By this means it has been demonstrated by installations in actual use that as high a degree of superheat as the most exacting conditions demand may be readily obtained, and the arrangement of the steam inlet and outlet tubes 5 and 6 in the direct path of the hot gases contributes to this result. The superheater supports are entirely independent of the boiler and may be of simple and cheap construction and character.

Having thus described my l11V11tlO11,Wl121i3 I new claim is:

1. The combination with a return tubular boiler, its settin and a bridge wall under the forward part of the boiler, of a super"- heater with its tubes arranged in horizontal rows back of the bridge wall and directly under the rear portion of the boiler, and a slab of infusible material niorable in line with the boiler and placed over the headers at the forward end of the superheater for regulating by the extent of its rearward movement over said headers the volume of that portion of the hot gases after they have passed over the forward portion of the boiler that will flow downwardly and then upwardly over the superheater tubes.

2. The combination with a return tubular boiler, its setting, and a bridge wall under the forward part of the boiler, of a superheater with its tubes in horizontal rows, placed back of said bridge wall and directly under the rear portion of the boiler, headers for said superheaters adjacent the bridge wall, and a slab of infusible material placed over the headers for protecting them from the direct action of the furnace gases which. after passing over the forward portion of the boiler flow downward and then upward over the super-heater tubes.

In testimony whereof I hereunto aiiix m y signature.

ERNEST H. FOSTER,

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