US128004A - Improvement in gas-and-air heating ovens - Google Patents

Description

GEORGE F. WILSON.

I Patented June 18., 1872.

improvement in Gas and Air Heating Ovens.v "No. 128,004

STATES PATENT O EIoE.

IMPROVEMENT IN GAS-AND-AIRHEATING OVENS.

Specification forming part of Letters Patent No. 128,004, dated June 18, 1872.

To whom it mayconce'rn:

Be it known that I, GEORGE F. WILSON, of Providence, in the county of Providence and .State of Rhode Island, have invented certain new'and useful improvements in Gas-and- Air Heating Oven, to be'used in connection with the gas-furnaces, in the process of manufacture of steel, for which Letters Patent of the United States were issued to me, on the 26th day of March, 1872, and numbered 125,- 107 and I hereby declare the following to a full, clear, and exact description of the same:

The use of gas-and-air heating ovens is desirable when the waste heat from gas-furnaces is to be used for heating boilers, &c.; or, as in the case of the process for making steel, referred to, the heating, or partial heating, of the converting-furnaces is effected in connection with them. In such cases the Siemens egenerating Gas-Furnaces can not be used, as all the waste heat from the gas-furnaces will necessarily be required for the heating of the regenerators.

The principle of construction of my gas-andair heating oven is as follows: The gas and air entering the oven by separate channels, pass through heated fire-clay retorts, so connected that there are two separate continuous channels, one for the gas and one for the air, all through the oven. The retorts may be heated by means of grate-fires, or, when desirable, gas-fires. In the latter case, the gas and air for the fires could not be previously heated, but would produce heat enough for the desired end. The gas and air can be made to pass through the heated channels of the oven by means of a back pressure, or the draught of a chimney, or both. The extra pressure need be only very slight in any case. That of the gas might be produced by means of an ordinary gas-holder, and that of the air by means of a fan-blower of low pressure, like those sometimes employed to supply blast to the large channels under the closed ash-pits of paddling and reheating furnaces. One desirable form for such a gas-and-air heating oven is represented in the accompanying drawing.

Its principal advantages consist in the sim-' plicity of construction and the ease with which leakages can be discovered, and consequent repairs to the retorts made. The drawing does not represent the latter; but the outer wall of the oven, in front of and behind each retort, (in each case an area of one square foot,) is to be only four and one-half inches thick. Thus any retort can easily be inspected or removed after merely removing partly or wholly the thin wall in front of or behind it. Another advantage consists in the reversibility of the currents of air and of gas. These features recommend this form of furnace or oven very highly. The two uppermost tiers of retorts are designed for heating the air, and the two lowermost the gas. In each case the body to be heated enters the oven at, and first passes through, the upper of its two tiers of retorts to the opposite side of the oven, when it passes down to and through the other tier. back again to the same side of the oven at which it entered first, whence it passes hot into the channel of ingress to the gas-furnace on that same side.

In the accompanying drawing, Figure 1 is a transverse vertical section on lineL M in Fig. 3. Fig. 2 is a longitudinal vertical section on line I K, Fig. 4. Figs. 3, 4, 5, and 6 are horizontal sections on lines A B, E F, G D, and G H, respectively, of 'an oven constructed in accordance with my said invention.

Figs. 3 and 4. show how the gas and air can be made to enter either end of the oven, according as it is necessary or desirable, to work the superincumbent gas-furnace in one direc tion or the other. Of course, when admitting the gas and air into the oven at one end, it is necessary to close the corresponding channels of ingress at the other end, as well as the connecting-channels between the oven and the exit-flues at the other end. By a proper management of the dampers at the dues leading from the oven into the chamber above, which connects. with the chimney, (not'represented,) a sufficiently even temperature of the retorts throughout the oven can be attained, although there will be a slight difference between the temperatures of the several tiers, corresponding to their proximity to the grate-fires which is, in fact, the reason why the gas and air are made to flow from one tier of retorts to and through that below it, instead of the reverse,

so that the last tier passed through may be the hottest, and the gas and air entering the gas-furnace may have a maximum attainable temperature. The partitions between the tiers of retorts should be made entirely of tiles, overlapping each other and carefully cemented together, to insure a minimum leakage in the joints. The vertical partitions need be only simple fire-brick work. The tiles are required for their supporting power. If firebrick work were employed in their stead it would have to consist of arches, (arch for tile,) which would increase the expense, and, from the multiplicity of joints, increase thetenden- H cy to leakage.

The horizontal tiles I prefer to make six inches thick; the holes for the admission of retorts, one foot square; and the retorts four feet long, with exterior diameter ten inches; interior diameter, six inches. The mode of closing the ingress of gas or air when required, and the arrangement of dampers for the regulation of the temperature of the oven, and for reversing, are not represented in the drawin g, as these are wellknown to persons skilled in the art.

This gasand-air heating oven, in connection with a gasfurnace, could be used with advantage in cases where great heat is required, but the waste flame from the gas-furnace would have a tendency to clog the regenerators, as in the case of certain smelting-furnaces, where volatile substances are sublimated. For example, in the smelting of silver-ores, Sie- Inens gas-regenerating furnaces have been applied with great advantage, (as indicated by an increase of one hundred per cent. in the production,) as long as the flues and passages of the regenerators were not clogged by sublimation from the flames of the gas-furnace; but, after a two-weeks campaign, it has invariably been necessary to take apart the regenerators and clean them. This entailed so much expense as to lead to the abandonment of the whole plan. In such a case, my oven, heated by grate-fires, could be employed with great advantage; while the waste-heat from the smelting-furnace could be used in heating the boilers where all sublimated material could easily and inexpensively be removed.

The dimensions, relations, number of retorts, &c, as represented in the accompanying drawing, may be varied without departure from my invention, according to the purpose for which the gas-furnace is to be employed, and according to the required temperature.

Having thus described my said invention, and the manner in which the same may be carried into effect, what I claim, and desire to secure by Letters Patent, is-

The herein-described air-and-gas heating oven or furnace, provided with separate series of two or more horizontal layers of tubes or retorts for passage of the air and gas, respectively, the air and gas being caused to pass in a tortuous path through the successive tubes or retort-s of the upper layer of their respective series, and thence down in a like path through the lower layer, in combination with fines for introducing and conducting off the air and gas into and from the retorts, so arranged that the air and gas may be caused to pass through the furnace in either direction at pleasure.

In testimony whereof I have signed my name to this specification before two subscrib- WM. A. MUNRoE, GUsTAvE MAeNrrzKY.

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