US101795A - Improvement in g-rate-bars for steam-generators - Google Patents

Description

MARSHALL3D.Y WELLMAN, OF ALLEGHENY COUNTY` PENNSYLVANIA.

Letters Patent No. 101,795, dated April 12, 1870.

IMPROVEMENT N GRATE-BARS FOR STEAM-GENERATORS.

The Schedule referred to in these Letters Patent and making part of the same.

To all whom it may concern Be it known that I, MARSHALL D. W ELLMAN, of the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Grate- Bars; and I do hereby declare the following to be a full, clear and exact description thereof, reference being had to the accompanying drawing making a part.

of this specication, in which- Figure l is a perspective view of my improved grate-har.

Figure 2 is a longitudinal vertical section along the line x x.

Figure 3 is a cross section along the line x'.

Like letters of reference indicate like parts in each.

The nature of my invention consists in the construction of a grate-bar, having a box or hollow face for the reception of ashes, and made entirely of thin plate metal, so that, while possessing the desired strength and durability, it will, with a minimum of metal, have a maximum -amount of surface exposed to the action of the air, and thereby always be kept at a comparatively low temperature.

In bars as heretofore constructed the face of the bar made much heavier than the weight of the lire abso-f lutely requires, and present comparatively a small cooling surface. Consequently there is an unneces- `:sary waste of metal, and also of labor in handling them, especially while cleaning out the grate, as well as a lack of the desired durability.

To enable others skilled in the art to make and use my improvement, I will proceed to describe its construction and mode of operation.

'The upper face of the grate-bar (figs. 1 3) is made hollow or of a box form, as shown, or, in other words, the flanges b at the sides and the center rib b', if such .be used, extend up a short distance. above the bearing plate a, which then constitutes the bottom of the box af. All these parts are cast quite thin, so as to have on the sides of the anges b, rib b', and lower face o f' bearing plate a, the maximum of heat-radiating surn face combined with a minimum of .thickness of met-al in anyone part. Hence, by the current of air which, rising from the ash-pit below, passes over the parts named, the grate-bar will be kept comparatively oooh' and is not liable to be burned out.

This result is still more perfectly secured by the introduction into the upper face of the bar of the box c', made in one, two, or.more divisions at pleasure.

This box soon becomes filled to the l upper edgesfof the anges b b with ashes, which, being a poor coliductor of heat, give the bearing plate a, as 'well as the inner faces of such ianges, the best possible protection against the action of the heat of the fire.

rIhe under side of thcbearing end d should also be cast with hollow chambers'c, surrounded at the sides and on top by thin plates in order to secure the most perfect and complete radiation of heat.

The grate-bar described may be made narrow or broad at pleasure, it only being necessary in broad bars to increase thc number of central ribs b', so as to secure the desired strength. In narrow bars this central rib maybe dispensed with.

I am aware that grooved or tluted faced-grate-bars for the reception of ashes are not new, and hence I claim the box form for the face of the bar only1 in connection with the thin plate sides and bottom, where: by in making the bars less metal lis required, and, in proportion to the amount of metal used, a maximum of radiating surface given, the better to prevent the bars from being injuriously aiected by the heat. l

What I claim as my invention, and desire to secure by Letters Patent, is- 'l 1. A grate-bar having thin plate bottom and sides or anges, inclosing a hollow or box face, so as, with a minimum amount of metal, to secure a maximum amount of heat radiating surface, constructed substantially as set forth.

2. Chambering out the lower face of the bearing ends of grate-bars, substantially as described.

In testimony whereof, I, the said M. D. VVELLMAN, have hereunto set my hand.

MARSHALL D. WELLMAN.

Witnesses s A. S. Nrononson, Tiros. B. Kn-RR.

Images