US22036A - Improvement in manufacture of white lead - Google Patents

Description

B. F. SMITH.

Manufacture of White Lead.

Patented Nov. 9, [858.

UNITED STATES PATENT OFFICE.

IENJAHIN F. SMITH, OF NE\V YORK, N. Y.

IMPROVEMENT IN MANUFACTURE OF WHITE LEAD.

Specification forming part of Letters Patent No. 22,036, dated November 9, 1858.

To all whom it may concern.-

Be it known that I, BENJAMIN F. SMITH, of the city of New York, in the county and State of New York, have invented a certain new and useful Improvement in the Manufacture of White Lead; and I hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, which form part of this specification, and in whieh- Figure 1 represents a front elevation of an apparatus for carrying into effect my new process in the manufacture of white lead; Fig. 2,-a side view thereof, and Fig. 3 a vertical transverse section of the same.

W'hite lead is produced by converting metallic lead. into carbonate of oxide of lead by either precipitating it from a solution of a salt of lead by means of carbonic acid or by carbonating the metallic lead under circumstances which effect the combination of the generated oxide of lead with carbonic acid. The latter mode has the advantage over the former, inasmuch as the product has more body or is of a more earthy or dense consistency, answers the purpose of paint better,

and is called b T chemists amorhus white lead, in contradistinction to the production by the first process, which is of semi-crystalline formation. The general principle upon which the latter method is conducted consists in exposing metallic lead to suitable acid fumes and afterward or simultaneously to carbonic acid, to which method of manufacture my invention relates. In such treatment of metallic lead it necessarily follows that the more extended the surface for a given quantity of the metal and the greater the exposure of its particles and freedom of circulation in, on, and around it the more thorough, economical, and rapid is its conversion into white lead produced by the combined action of the acetic vapors and carbonic acid. Much attention, therefore, has been bestowedon preparing the metallic lead for such exposure. The present most advantageous method appears to be to pour melted lead on aniron plate placed over a boiler and on the surface of the metal beginning to consolidate, sloping the plate so as to run off the still liquid metal and leave a lead sheet of extreme thinness.

A series of these sheets is then suitably hung in a close box for the action of the acids, as specified.

My improvement has for its object the preparing in a better form for the action of the acids the metallic lead, and at the same time to simplify and expedite the process.

I do not confine myself to any particular form or arrangement of details, as these may be almost infinitely varied, but in the accompanying drawings and following description will be found explained a means for carrying my new process into effect which is sufficient is tapped or allowed to run off, as required by a horizontal or inclined pipe 0, terminating in a cross perforated pipe or sprinkler D,the perforations in which are supposed to be arranged along the lower surface of it and of suitable size and arrangement as to permit of the melted lead being discharged therefrom in thin and divided streams at a suitable distance apart. Underneath this sprinkler and parallel with it is shown a horizontal and corrugated cylinder E, arranged at any given distance from the sprinkler, and which may be situated in a lower chamber of the building,

so as to receive on its top in front the streams or shower of metallic lead in its fluid state issuing from the sprinkler. The corrugations in the cylinder are here represented annularly around the cylinder and pitched to correspond with the perforations in the sprinkler. The lead forming or dividing the corruga tions may be of arched form in their crosssection. This cylinder E is madehollow and mounted in suitable standards at either end and is designed to rotate rapidly in the direction indicated by the arrow min Fig. 2. It

keeping up a running supply of cold water to it internally or through it.

From this description it will be seen that the stream of melted lead falling from the sprinkler on the corrugated surface of the rapidly-revolving cooling-cylinder will be almost instantaneously solidified. and broken and thrown off by the centrifugal force in a series of thin detached spangles of rough formation and more or less arched in accordance with the curvature of the cylinder. These spangles present, therefore, a most advantageous and extensive surface for the subsequent action of. the acetic vapors on and through or among them by suitably piling on racks in aclose chamber for the purpose, and are in every way superior and more convenient than sheets or coils, as heretofore used, while the rapidity and economy with which they may be produced form also considerations of some importance. It will be readily perceived that substantially the same operation is effected by any manner of cansing the stream of lead to pass through perforations arranged longitudinally in relation to each other and parallel with the axis of the rotating cylinder.

In Winteri. c., when the surrounding atmosphere is comparatively cold or whenthe material of which thepot and its apptlrte' nances are constructed are of such a thick ness as to cause the lead to coagulate and to clog up the orificesI surround the outletpipe with burning charcoal placed in an augur provided with a series of orifices at its lower edge, and which I use instead of the perforated pipe. I

That I claim as my invention, and desire to secure by Letters Patent, is

1. Preparing the metallic lead for the purposes of perfect corrosion by exposure to the action of acids or other substances in spangles of the size and configuration substantially as herein described.

2. Preparing the metallic lead for the purposes of perfect corrosion by exposure to the action of acids or other substances by causing melted lead to drop in a finely-divided stream or streams upon acorrugated cylinder or its equivalent, revolving or moving so as to throw off solid spangles of more or less the form and thickness herein described.

In testimony whereof I have signed my name to this specification before two subscribing Witnesses.

BENJ. F. SMITH.

Witnesses:

A. POLLAK,

WM. D. RUssELL

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