US1901543A - Metallurgical condenser - Google Patents

Description

March 14, 1933. G. F. wEAToN METALLURGICAL CONDENSER Filed Feb. 2s, 1952- WEL EL@ n 1 64. lll/ll a. ua? vd...

ture of condensation decreases with increas- Patented Mar. 14, 1933 UNITED STATES PATENT oI-Flcn GEORGE l'. WEATON, Ol' BEAVER, PENNSYLVANIA., ASSIGNOR T0 ST. JOSEPH LEAD COHIANY, OI NEW YORK, N. Y., L COBPOBATICN OF NEW 'YORK l IETALLUBJGIQAL CONDENSEB application and :february as, 193s. seran ne. 595,365.

'The empirically worked out condenser designs which have given a degree of satisfactory performance in the smelting of zinc in the conventional horizontal retorts have proved to be entirely inapplicable to the radically different conditions presented by the smelting of zinc in electrothermally or externally heated shaft or vertical retort furnaces. Chief among these different conditions are the increased volume of vapor to be handled and the altered ratio of zinc vapor to noncondensible gases produced in such furnaces.

The increased volume of gases cannot be effectively compensated for by merely pro-v portionately increasin the size of previously used condensers for t e reason that such an increase in size results in different ratios of volume to effective condensing surface and effective radiation surface of the condenser. Relative gas velocities and rates of diil'usion also lay importait roles in the condensation ro lem and their effect on the efliciency o condensation must be taken into account in condenser design.

The ratio of zinc vapor to non-condensible gases directly effects vitally im ortant condensation conditions. The initial tempera- *ing dilution of the zinc vapor by non-condensible gases, while the residual uncondensible zinc content of the gases at any ven temperature will, of course, increase wit increasing dilution of the zinc vapor.

"Provision must be further made in an eiicient condenser for the coalescence of minute drops .of condensed liquid zine andv it is particularly desirable to provide for the positive assistance of such coalescence.

The condenser of the present invention is particularly adapted for the effective condensation of zinc vapor coming from electrothermally and externally heated shaft or vertical retort furnaces. It provides the 'proper ratios of condensation surface, radiation surface, gas volume vandgas velocities. l

It provides the proper temperature gradient for eiiicient condensation of zinc Vapor from the progressively impoverished gases passlng through the furnace. It provides positive assistance to the coalescence of the small drops of liquid zinc collecting on the condensation surfaces. It provides further a simple and effective construction, readily accessible for inspection, cleaning and repair, and of the utmost simplicity and elliciency of control.

A The invention will be more fully described wlth reference to the embodiment illustrated 1n the accompanying drawing, in which:

F1 re 1 is a vertical section on line 1--1 of Flgure 2; U

Figure 2 is a partial horizontal section on line 2-2 of Figure 1; and

Figure 3 is a vertical section on line 3 3 of Figure 1. l

Vapors from the smelting zone 1 are admitted into annular chamber 2, if a shaft type furnace; or, if a rectangular furnace, this chamber maybe arallel to the length of the furnace at any esircd elevation, connection being made into the annular chamber 2 by a plurality of ports 3. Advantageouslythe effective area of the ports is suilicient to maintain a velocity of to 70 feet per minute 'through said ports, the vaporsy of condensing surface, including baiiles, per

pound of vapor per 24 hours.

bottom of the condenser cham r, where they.

cooperate with the pool of liquid metal retained in the bottom of the chamber to revent the flow of gases under these ba es.

4Alternate bailles 5a contact with the top of l the chamber at their upper ends and extend downward to a point above the surface of the pool of liquid metal in the condenser chamber.

Passing out of chamber 2 into main condenser 4, the vapors are caused to impinge against the first of the bailes 5, which will change their direction, causing the major portion of the gases or vapors to travel over the top of said bailie 5, passing downward between 5 and 5a, then again upward, taking a sinuous path between bailies 5 and 5a until the uncondensed gases finally pass out from exit 6. The bailles 5 and 5a are inclined, preferably at an angle of about 221 with the vertical. Due to the regularity of the vapor production by the furnace of the type for which the condenser is especially adapted, insulation 7 on condenser 4 may be advantageously installed in a rmanent manner. Batlles 5 and 5a and llning 8 of the condenser may be made of silicon carbide or cast mullite, these refractories not being readily attacked by zinc at the temperatures prevailing within the condenser.

Temperatures within the condenser are indicated by pyrometers 9. Regulation of the furnace pressure may be effected by regulation of the size of the orice in exit 6. Metal is withdrawn from the condenser through tap block and spout l0. Accessholes 11 are provided by means of which any accretions which form within the condenser may be loosened and raked out. The whole condenser may be set in a steel box l2 iilled with finely crushed coke 13 well covered with re clay, upon which is placed a base of iirebrick 1 A particularl valuable characteristic of the inclined bacs of the condenser of the invention is the positive assistance which they provide to the coalescence ci small particles of liquid zinc 'formed in the condensation. The minute particles of zinc formed by, condensation from the vapor will be deposited principally upon the upper surfaces of baihes 5 and 5a, although some deposition will take place on the lower surfaces of these bacs also. The velocity of the gases and vapors and 'such condensed metal as has al ready coalesced is su'cient to disturb any smelt., uncoaleseed globules and to smetti-acm below the normal level of liquid metal in said chamber, and a plurality of inclined ballles alternating with said first-named baiiles and extending from the top of said chamber to a level above the normal level of liquid metal insaid chamber.

2. A metallurgical condenser comprising a chamber and a plurality of bailles inclined at l an angle of about 221/ with the vertical providing a tortuous up-and-down path for the gases therethrough. 3. A metallurgical condenser comprising a chamber, a plurality of baiiles, inclined at an angle of about 22%" with the vertical, spaced from the top of said chamber and extending below the normal level of liquid metal in said chamber, and a plurality of baffles alternating with said first-named baiiles and similarly inclined, extending from the top'of said chamber to a level above the normal level of liquid metalin said chamber.

4. A metallurgical condenser comprising a rectangular chamber having a ratio of width to height of about 1 to 5, a plurality of bailles, inclined at an angle of about 22%" -with the vertical, spaced from the top of said chamber and extending below the normal level of liquid metal in said chamber, and a plurality of batlles alternating with said iirst-named bales and similarly inclined, extending from the top of said chamber to a level above the normal level of liquid metal in said chamber. 5. A method of condensing metallic zinc from gases containing zinc vapor which comprises passing said gases in a relatively narrow stream vin a tortuous up-and-down path in contact with inclined condensing surfaces, the zinc vapor being passed at a rate of about Aone pound per 24 hours per 2% square inches of condensing surface.

in testimony whereof, il adix my signature.

GEORGE F. WEATON.

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