US1080864A - Electric zinc-furnace with integral compound condenser. - Google Patents

Description

J. THOMSON. ELECTRIC zmo FURNACE WITH INTEGRAL COMPOUND CONDENSER. APPLICATION FILED JAN. 2, 1913.

1,080,864 Patenteci Dec. 9, 913.

Whn 655652 Y J. THOMSON. ELECTRIC ZINC FURNACE WITH INTEGRAL. COMPOUND CONDENSER.

APPLICATION FILED JAN. 2,1913. 1,080,864. I

' pcentea Dec. '9, 1913.

2 SHEETS-SHEET 2.

v Q I Wifnassem LFGHN TK-IGIESON, i315 NE' FY YORK, N.

INTEGRAL CG'MPOUND CONDENSER.

i r. o In meldin -c4111.

Application filed January 2, 1913.

citizen oi. the United States, and. resides" of the borough of Manhattan of the city of New York, in the county and State oi York, have invented certain new and ful Improvements in Electric Zinc-Furneces with integral Compound Condensers, or which the following is c. specification, reference beingmade to the uceompenyirg drawings, forming e' pert hereof.

This invention relates to the metallurgy of Zinc, having for its object the production of zinc fume by thermochemical reaction and then condensing the turns to liquid metal.

A description of the means at the desired results and such an clue of general principles applicable ther us will clearly disclose the invention be concurrently pointed out in connect with the description of the ace mpuny drawingsforming av part of this specificstiou and in which drawings there is illus trated one embodiment the invention.

In said drawings Figure l is e. iJNl'lSVGFFJQ center section of a combined co and condenser. in the lower or left hand portion of this figure the. resistor and charge material have been omitted. 2 is m halt top plan View, as on C, C l, and Fig. 3 is e detached sectional diagram along the longitudinal center line 'l-Cl'lis furnace is particularly intended for the reduction of oxid of zinc combined with carbon as the reagent, whereby, when adequately hosted the following representative reaction ensues, namely:

or less limited amount of residual matter is l diiiiculty which is encountered in e successful commercial result.

Specification of Letters Eatent.

Thomson, :2.-

Putented Dec. 9, 1913.

Serial 1-10. 239,792.

The heat necessary for decomposingthe charge is preferably derived from an electric current passed through a broken bed of carbon resistor, the charge being acted upon by direct conduction of heat.

The bed of carbon. resistor H is disposed along the longitudinal center of the furnace. its ends being interpolated between terminals 4 to which the electric current is tluoted by copper electrodes 5. This resister sustained bye series of spaced grate bars 6 which in turn rest upon ledges, T, formed in a shallow tomped casing R; Beneath the grate bars there is a sump n in which the inert residual matter 8 is collected. in the les 9 of the casing, which coniine or form the boundaries of the resister, are a. series of 0penin'gs,-slits or ports 10 whose bottoms extend down to the ledges upon which the grate bars are supported. '5 he tops of the said ports are covered by refractory plates, as 12. Two condensers J, J are employed. och being parallel and immediately adjacent to the side walls of the resistor cusing, hich in fact provide a. part oil the inner walls of the condensing chambers.

The resistor carbon is of sufiioient depth to fully cover the inner openings of the ports 10. charge material P is fed to inc the upper face or the resistor through verticul galleries Fig. 3, formed by a series oi spaced slabs or plates 14. The volatilized products of the reaction pass down into and through the transverse Zones under the slabs or plates, and from which zones it may flow in various directions through the carbon to the grate bur spaces 15 and thence to the ports as in the manner indicated by the flow arrows 16. The residue may either sift or percolui'c or be poked down through the resistor and fall into the sump through the grate bur spaces as indicated by the arrows 17. After passing through the bed of carbon resistor the fume and gas will be free of any pernicious oxidizing agent such as CO and will also be at substantially the temperature of the resistor and hence the outflow from the ports 10 into the free spaces 6, c of the condensers will maintain a temperature therein approximating that of the sidewalls of the resistor casing. To realize this condition to the utmost extent the material of the outer walls 18, 18 of the condensers should be of the best non.- heat-conductive refrac tories and the same applies to the cover tiles 19 and also the overlying bricks. The latter may further more be sheathed with charge material to seal the joints and afford additional heat insulation.

An advantage of the foregoing construction and arrangement is that the heat necessarily carried away by the fume and gas assists in maintaining the temperature of the resistor casing walls and thus prevents a material direct and additional conduction of heat away from the sides of the re sistor itself, and consequently there Will'be little or no thermalloss from the resistor. Moreover, the right and left hand condenseas act as thermal blankets to the cen .trally disposed resistor and also aid in main t'aining' a minimum thermal loss from the resistor.

The condensation of the clean fume received in the spaces 6, i's-efiected by causing it together With its entraining en velo'p of CO to pass downwardly throurh several series of slits or spaces 20 formed 'by cross-stacked and preferably staggered plates 21 set on edge and arranged longitudinally along and transversely of the condenser chamber casings. These plates usu ally comprise a large percentage of carbon or graphite and afford a large superficial surface and also provide an ample for primarily absorbing heat from the vola-' tilized products of the reaction and then rapidly and progressively conducting away the said heat.

The latter condition is obtained by building the battery of condensing plates upon a series of supports 23 that are partially Inersed in a bath of liquid zinc 24 which is maintained at about a constant depth in bottom of the condensing chamber and the temperature of which bath is under control. The temperature of the said bath is con-- trolled according to the rate of evolution of fume and gas by causing a circulation of hot gases or of cooling air, as the need may be, through the chambers or times Y, 1", situated beneath the condensers. The thermal conditions may be illustrated by assuming a case, thus: The bath must be maintained at a safe temperature aboye its freezing point which is about 7 Let this temperature of the bath betaken as 850 Now, if the fume and gas in the spaces 6, c, as they enter the slits has a temperature of say 2300 F. and if the upper edges of the plates have a temperature of say 2200 F. then there will be a difference of I350 F.

,hetyyeen the upper series of plates and the '60- mersed in the bath. As it will be suificient .ifthe fume and gas is chilled to a temperaportions of the supports 23 which are imtureof say 1050 F. this means a drop of 1250 and leaves a reserve chilling difference in the condenser of 100 F. between reac es the upper plates and the top of the bath. The final exit of any residual fume and the original CC from the lower series of plates is in the form of narrow sheets, which inipinge directly upon the surfaces of the baths and which react and flow right and left to subsequently ind through the openings or ports 25., 26, into the large chamber or tine X beneath the resistor, thence to atmosphere by a tube or tubes During the slow transit through the large chamber X the stored heat in the gas acts to conserve the temperature in the sump.

The condenser plates n1 y be narrow or wide, thick or than nd set to provide slits oi. any desired iviiflth. nit it desirable that the a figs-to area of the slits shall be such as to insure a lov; vclocit, of flow there}, through. The spacing of the longitudinal and transverse plates may be such as to obtain an equal flow area through each series or the velocity may be more rapid through one series than the other. the flow area is uniform from top to bottom the velocity oi? flow will constantly diminish, due to the reduction of volume as the temperaturelo'wers, hence the plates may be stacked so that the spaces between them will be lessened and so that the number or thickness of the plates in a series may be increased grcssively downward.

' In design having central resistor combined with compound condensers it is advisable and quite essential that the evolved products of the reaction shall have a primary free escape from the seat or seats of the reaction, that the heat developed in the resistor shall be largely utilized precisely at the seat or seats of the reaction, that vol ized products of the reaction shall be delivered into the condensers in such manner as to insure a uniform dispersion volnine and 'ilOW through the condensing systern, that the velocity of flow imparted to the fume anc gas shall be relatively slow, that large or objectionable baclcpressure of fume and. gas shall not be set up against the seat or seats oi"; the reaction and that the means for absorbing and dissipating the stored heat 'in the fume and gas shall be adaptable to the rate atwhich they are evolved. These features, jointly and severally, are herein :tully disclosed, but it is manifest; that the improvements herein set forth are not limited to the precise construction and arrangement shownand described, as they may be embodied in various forms and modifications, and that various changes and alterations in the manner and method of Working may be made Without departing from the spirit and essence of the invention.

What I claim is:

of-carbon resistor supported on a grate osoeee above an underlying residue sump and located between confining side walls having a series of lateral openings or ports leading to condensers on opposite sides of the resistor.

2. An electric zinc smelting furnace having a bed-of-carbon resistor supported on spaced grate members above a residue sump, condensers located on opposite sides of the resistor, a resistor rota iing side wall providing'a part of the inner wall of the condenser and having openings therein through which fumes can pass directly from the resistor to the condensers.

3. A combined electric furnace and condenser having a resistor, resistor retaining walls contiguous to the sides of the resistor, said walls being provided with openings through which fumes can pass directly from the resistor to the upper portion of the condensers which are arranged on opposite side of the resistor. 7

4. An electric furnace having a resistor supported on spaced grate bars below which is a sump, the resistor beingretained in place by walls having therein openings for conducting the fumes and gases t a condenser or condensers, the top portions of said openings being below the top of that portion of the resistor adjacent thereto and the lower portion of said openings communicating with the space between the grate bars whereby any fumes or gases which pass through the resistor to the space between the grate bars can flow directly through said openings to the condenser orcondensers.

5. In an electric zinc smeltingfurnace, a resistor casing having a series of resistor supporting spaced grate bars and perforated side walls which form a part of the walls of.

condenser-s along the sides of the said casing. G. In an electric furnace of the resistor type, resistor casing side walls having transverse ports, the upper portions of the inner portions of which are partially closed by the sides of said walls for receiving the volatilized products of the reaction after they will have-passed through the said resistor.

8. A condenser combined with a suitable source of supply of zinc fume or of fume and gas, said condenser having a battery of spaced cross stacked and staggered plates sustained by supports at least partially immersed in a bath of liquid metal.

9. An electric zinc furnace adapted. to effeet the reaction of ZnO-l-C,-and side condensers for receiving the volatilized products of the reaction and provided with cross stacked plates set edgewise to the direction of the flowing fume and 10. In an electric zinc furnace, a resistor having subdivided zones through which the volatilized and the inert products of the reaction respectively flow and gravitate, combined with perforated sidewalls forming portions of the inner walls of condensing chambers, a series of spaced grate bars and an underlying sump.

11. In a furnace and condenser, a resistor for efiecting substantially the ZnO+C re action, the volatilized products thereof being passed into and through the said resistor, combined with one or more condensers comprising a system of heat absorbing and heat conducting plates, the upper portions of which have a temperature approximating that of the fume and gas and the lower portions of which have a temperature approximating that of liquid zinc.

12. A combined electric furnace and condenser having a resistor above a sump, condensers on opposite sides of theresistor arranged to receive inthe upper portions thereof the products of the reaction, and a chamber or chambers below the sump into which the residual gases from the condenser pass prior to their exit to the atmosphere.

13. A zinc condensing apparatus having a plurality of condensing chambers provided therein with spaced cross stacked members located over baths of molten zinc so that fumes passing, downwardly through said stack will impinge against the top surface of the bath, and a chamber under the sump for receiving the residual gases from the condensing chambers.

14. A zinc condenser having a plurality of condensing chambers provided with liquid baths at the bottom, a common chamber into which the residual gases from the condensers flow and provided with a common cooling or heating means below the liquid baths.

This specification signed and witnessed this 31 day of December A. D. 1913.

JOHN THOMSON.

Signed in the presence of EDWIN A. PACKARD, D. IIAROLD BUSH.

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