US247157A - Hot-blast pyrometer - Google Patents

Description

(No Model.)

B. BROWN.

HOT BLAST PYROMETER. Patented Sept. 20, 1881..

u. Pains, Phalo'lnhographnn Washmglon, a. c.

UNITED STATES PATENT OFFICE.

EDWARD BROWN, OF PHILADELPHIA, PENNSYLVANIA.

HOT-BLAST PYROM ETE R.

SPECIFICATION forming part of Letters Patent No. 247,157, dated September 20, 1881.

Application filed March 19, 1881. (No model.)

To all whom it may concern:

Be it known that I, EDWARD BROWN, of 311 Walnut street, Philadelphia, Pennsylvania, have invented a new and useful Hot-Blast Pyrometer, of which the following is a speeification.

Theobject of my invention is to indicate the temperature of the hot-blast used at iron smelting-furnaces, where a blast above red heat is produced by regenerative fire-brick stoves.

The invention is an improvement upon my patentofJune1,1869; auditconsists,briefly,in the combination of a pyrorueter-uozzle having inlets for hot and cold air, with the metal expansionbar of the pyrometer inclosed in a conducting-tube, the expansion of the said bar communicating its motion through a lever to the pointer of a dial which is fixed upon a nonexpandingbar outside of the conducting-tube also, in the construction of the nozzle of the pyrometer with a valve having a stop or screw, whereby the relative proportions of hot and cold air may be accurately adjusted and fixed at any desired proportion; also, in the couvertible feature of the instrument, either to indicate the lower temperature from iron stoves by the full heat upon the expansion-bar or the red-hot blastfrom regenerativefire-brick stoves by a fixed relative heat.

Figure 1 is an elevation of the pyrometer, partly in section. Fig. 2 is a front elevation, showing the double dial. Fig. 3 is an outside view of the cold-air inlet and valve.

A is a hollow tapering nozzle, of cast-iron, having a flange, a, and a guard of sheet-brass, 0. to deflect the blast away from the operators hand. The nozzle A is screwed to or cast as a part of the hollow casting B. The casting B is bolted rigidly to the mahogany bar 0. Au iron pin, b, passes through this casting B, and also through the expansion-bar D of the pyrometer and through the conductor 6. The conductor 6 is of thin sheet-iron, inclosed in a brass tube, 0 the latter being secured to the casting B. This double conducting-tube e c slides in a ring, F, at the upper end. The ring F is fastened rigidly to the mahogany bar 0. The upper end of the thin expansion-bar D is pivoted to the lever B, which rocks upon the fulcrum h in the forkedjoint K. Thejoint K is secured rigidly to the mahogany bar 0.

At the opposite end of the lever there is an adjusting-screw, m,jointed at its lower end to the connecting-link n. This link, entering the gage, is connected with a lever which moves the toothed segment and pinion of the pointer L, common in steam-gages, and by this means the elongation of the bar D is communicated to the pointer L upon the dial. The dial is double, having one row offigures to 1,800 the other row to 1,200 or some other definite proportion of the larger number, as one-halt, onethird, three-quarters.

The casting B, with a conical nozzle, A, is hollow, and has drilled through it one or more cold-air inlets,W,which are covered by a springring, S, which slides stifliy and can be moved on or off the holes W. A screw, S, passing through a slot, is used to secure the ring or valve S in its place after being adjusted. The conducting-tube 6 projects into the castiu g B beyond the end of the expansion-bar I), and terminates just above the air-inlets W. A tube, P, is screwed into the end of the nozzle A and projects in to the end of the conductor 0.

The instrument is operated and adjusted in this manner: First, cover the inlets W with the sliding valve S, remove the small interior pipe P, and the instrument can be used to admit the full temperature of the blast upon the expansion-strip up to red heat about, 1,000 to 1,200 When the. same instrument is required to indicate the hot-blast from regenerative stoves where the temperature may be 1,800 the tube P is inserted and the valve S brought to cover so much of the holes as may be requisite. Theinstrumentwithoutmyimprovement is tested at some temperature below 1,200 We will assume it is lowered for the experiment to 900 of blast, as indicated by the outside dial; the tube P is then inserted and cold air admitted by the valve until the pointer shows 600, or two-thirds of the heat on the same outside dial. This in reality is 900 of blast, as shown by the inside dial, but only 600 upon the expansion-bar. The inside dial may be omitted and the temperature calculated by adding fifty pereen t. Thus 800 plus 400 equals 1,200 of blast. The pointer having started at 0 Fahrenheit, the temperature of the atmosphere must be added to 1,200 for perfect accuracy. This interchangeable construction gives every furnace-tender the means of testing and adjusting his own instrument according as the pressure of blast or the temperature of the cold air may vary from one season of the year to another. The expansiontube of the ordinary Gauntlett pyrometer may be inserted within the conductor 6; but the combination is inferior to the one shown, 0wing to the longer time required to take an indieation.

By this construction I obtain an instrument accurate and durable, easily tested and adjusted to a high or low pressure of blast, and convertible from a low-temperature instrument to one indicating the highest practical temperature of blast attainable at present.

I do not broadly claim the mixing of cold air with the hot-blast and indicating the same, but theparticular combination of devices which accomplish that end.

1. Ina hot-blast pyrometer, the combination of a nozzle having an inlet-pipe for hot air and a cold-air inlet capable of being closed or adjusted to different areas, a metal expansionbar, a conducting-tube inclosing sald bar and surrounding the upper end of the hot-air inlet, and alever connecting with the expansion-bar and with the pointer of the dial, substantially as and for the purposes set forth.

2. In a hot-blast pyrometer, a device adapting the instrument for low and high temperatures, consisting of the nozzle A, a cold-air inlet, and means for closing it or decreasing its area, combined with the hot-air inlet P, substantially as set forth.

3. The nozzle A, having cold-air openings and means for closing them or decreasing their area, the conducting-tube e, and the hot-air inlet I, the upper end of which extends with,- in the conducting-tube, combined with the expansion-bar l), substantially as and for the purposes set forth.

4. In a hot-blast pyrometer, the combination of a hot-blastinlet, P, a coldair inlet controlled by a valve, an expansion-bar within the conductor e, which operates apointer, and adouble dial having the spaces of one of them in a fixed proportion to the spaces of the other, so that the same instrument is interchangeable either for use with the full temperature or with mixed hot and cold air.

EDWVARD BROWN.

I Vi tnesses:

PARK MFARLAND, J r., JOHN F. GRANT.

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