US446987A - tilghman - Google Patents

Description

UNITED STnTns FATENT @rricn,

' l-llflNJAMlN C. 'lllitlllftlAN AND RICHARD A. TILGHMAN, OF PHILADELPHIA, PENNSYLVANIA.

METHOD on reassess-mains eart -season: GLQBULES.

SPEGIFICATION forming part of Letters Patent No. 4.4.6387, dated February 24, 189i. Application tiled March 17, 1390 Serial No. 844,233. (No specimens.)

To ail whom it may concern.-

Be it known that we, BENJAMIN O. TiLeu- MAN and RICHARD A. TILenMAN,both of the .city and. county of Philadelphia, State of 'Pennsylvania, have invented a certain new and useful Improved Method of lvlanufacturing Chilled-Iron Globules, of which the following is a'true and exactdescription, reference being had to the accompanying drawings, which form a part of this specification. Our invention relates to the manufacture of chilled-iron globules such as are used in the abrading process described in the patent to Benjamin C. Tilghman, Reissue No. 7,499, dated February-6, 1877, also to some extent in the sand-blast process. These globules are manufactured in the following way: A stream of melted iron is exposed to the action of ahigh-pressure jet of steam or gas with the- 7 2,0 result of atomizing it, and the spray of iron particles is thrown into the air, Where the particles assume a spherical form and become chilled on the surface, so as to take a permanent set or form. Then they fall into a tank of water while still intensely hot, and being small they are rapidly and thoroughly chilled, becoming intensely hard. then removed from the water and dried preparatory to being packed for shipment. At

0 two stages of the above treatment the globules are exposed to the oxidizing influence of the a'irn amely, when the melted metal is sprayed into the air, when, owing to its great heat, the'iron combines directly with oxygen,

an actual burning taking place, with the formation of a crust or scales of dark oxide, and

during the, process of drying, after removal from the chilling-tank, when the wet globules are acted on by the oxygen of the air, 0 forming a friable coat of reddish oxide or rust. This rust is objectionable for many reasons. Nith certain delicate stones it is liable, unless great care is used, to stain the surface of the stone, and when used for giving a frosted surface to metals by means of the sand-blast the rust is hammered into the metal under treatment, injuring its color and appearance. The rusted globules are also unsightly, and the fr able reddish rust'formed 59 in drying soils whatever it comes in contact wit The globules are The object of our inventionis to manufacture globules of chilled iron. having casehardened unpolished but bright clean metallic surfaces and which will be free from the above-noted objections. Such globules are in themselves a new article of manufacture, having pronounced advantages over the globules, heretofore made, and as such the subject-matter' of another application for Letters 6 Patent filed March 17, 1890, Serial No. 344,234.

Our. present invention consists of the hereinafterdescribed method of making such globules.

- WV-e atomize the melted iron or steel by .means of a high-pressure jet of steam or gas,

as before,but surround the spray of metal by anon-oxidizing atmosphere s'uch, for instance, as the gases produced by passing air througha deep bed of ignited fuel. This is 76 most economically and conveniently done by introducing the non-oxidizing gas around the atomizing-jet in such a manner as to. supply the suck caused by the same completely. The non-oxidizing gas is then forced by the atomizing-jet to accompany and envelop the atomized material until it is received in the Water of the chilling-tank. This treatment efiectually prevents the burning of the surface of the hotglobules, which are received in the chill- 8o ing-tank free from the crust or scale formed- When the atomized material is thrown into an atmosphere containing oxygen. In order to-insure the production of globules having clean and bright metallic surfaces, it is nowonly necessary to prevent the formation of the friable red oxide in the process of drying, and this we accomplish by drying the glob ules in a non-oxidizing atmospheree that is, by surrounding them while drying 'by an at 0 mosphere deprived of oxygemsuch as is produced by passing air through a deep bed of ignited fuel or by-a gas or vapor produced in any way and which contains no free oxygen, and will while present excludeihe air-such, 9 5 for instance, as steam.

Among other experiments we have ascertained that by subjecting the wet globules to a high heat in drying them we not only dry them more quickly but also obtain them free from the red rust owing to the rapid vaporization of the water upon their surfaces, the

vapor or steam being driven off at once from the granules directly exposed to the heatingsurface and forming a protecting atmosphere around them, and also rising through the granules above, driving off the air and effectually excluding oxygen and preventing its injurious action. The same effect of course is produced by passing steam from a boiler into the chamber containing the granules or by similarly introducing any no n-oxidizing gases.

In another application which we are about to file wehave claimed, broadly, the method of manufacturing globules by atomizimg them in a non-oxidizing atmosphere and drying them under conditions which preclude the formation of rust, and also specifically a treatment for preventing oxidization in drying, and our present invention is limited to a treatment in which the drying is accomplished in a non-oxidizing atmosphere.

Having now described our invention, what We claim as ne\v,and desire to secure by Letters Patent, is-

1. The described method of manufacturing chilled-iron globules, which consists in atomizing melted metal, chilling the globules in water, and then drying them in a non-oxidizing atmosphere. i

2. The described method of manufacturing chilled-iron globules, which consists in atomizing melted metal in a non-oxidizing atmosphere, chilling the globules in water, and then drying them in a non-oxidizirgatmosphere.

B. C. TILGIIMAN. R. A. TILGHMAN. Witnesses as to B. C. Tilghman:

ARTHUR C. HALL, r HENRY-BLAIR,

'9 Mount SL, Zll'anchester. Witnesses as to R. A. 'lilghman:

' LEWIS R. DICK,

JOSHUA MATLACK, Jr.