USRE10109E - Grinding and sieving caustic alkali - Google Patents

Description

W. J'. MENZIES,

Assignor of onehalf to G. T. LEwm GRINDING AND SIBVING GAUSTIG ALKALI. No. 10,109.

Reissued May 9, 1882.

lllllll WITNBSSS i 2 INVENTOR ATTORNEY UNITED STATES PATENT OFFICE. v

WILLIAM J. MENZIES, OF SAINT' HELENS, OOUN'IY OF LANCASTER, ENG- LAND, ASSIGNOR OF ONE-HALF TO GEORGE'T. LEWIS, OF PHILADEL- PHIA, PENNSYLVANIA.

GRINDING AND SIVING CAUSTIC ALKALI.

SPECIFICATION forming part of Reissued Letters Patent No. 10,109, dated May 9, 1882. Original No. 243,939, dated July 5, 1881. Application for reissue filed April 12, 1R82. Patented in England October 2l, 1.879.

DIVISION B.

To all whom it may concern Be it known that I, WILLIAM JONES MEN- ZIES, a British subject, residing at Saint Helens, in the county of Lancaster, England,have invented certain new and useful Improvements in Grinding and Sieving Caustic Alkalies and in Apparatus therefor, (for which I have received Letters Patent in England, No. 4,274, dated October 21, 1879,) and I do hereby dcclare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same.

In grinding caustic alkalies great diiculty is experienced, owing to their deliquescent nature, and annoyance experienced from the fearfully corrosive dust tlying about. This has hitherto almost prevented these chemicals being ground to a commercial extent, though they are vastly more convenient if finely and evenly comminuted. I find, however, that by grinding or crushiug caustic alkalies while hot the deliquescence is not perceptible, and by grinding or crushing andnimmediately sieving in a close mill the dust nuisance is minimized. I melt the caustic alkalies and pour them onto suitable plates, and when consolidated, but still at a high temperature-sufticiently high to prevent any perceptible deliquesccncegrind and sieve the same by passing them through a suitable mill; or, if the caustic alkalies have been allowed to cool, they may be ground and sieved by heating the mill or the atmosphere through which they pass to a telnperature sufficienti y high to prevent any perceptible deliquescence-as if the caustic alkalies were hot-by steam-pipes or other wellknown Inechanical means for applying heat. 1n grinding and sieving the caustic alkaliesI use preferably au ordinary grinding and sieving clay-mill, but covered in below with a stationaryabottom underneath, and scraper moving around upon it and scraping the sieved and powdered alkali (which has fallen through the sieve-plates above onto the bottom of the closed chamber below) out through apertures at the bottom into the barrel placed underneath, as shown in the annexed drawings, in which- Figure 1 is an elevation, and Fig. 2a section, of my improved apparatus.

A A are the grinding-rollers, as in an ordinary mortar or clay mill; B, shaft; carrying same; aa., Scrapers bearing againstperiphery ot' rollers A A, O, steel or other hard plate carried by cast-iron pan D,`\vhich latter is keyed to shaft E and rotated by bevel-gearing F G, iiy-wheel H, crank I, and engine J; K, walls of pan; L, grating, M, stationary bottom; N,scrapers scrapingthe finely powdered and sieved caustic that falls on the sheet 1n bottom M into spout T in said bottom, througlr which thc powder falls into a barrel, Q, preferably placed on a trolley, asshown.

Many other forms of combined sieve and grinder will do, so long as the sieving im mcdiately follows the grinding and the caustic alkalies are ground hot, or the mill and apparatus or atmosphere in connection with or surrounding the same is sufciently heated by steam-pipes or other suitable means for applying the heat.

- In actual practice I use caustic sufficiently hot and guard it from currents of air and pass through such a quantity in such a manner as to avoid having to heat the mill with steampipes, Ste.; but, if desirable, the pan could be made hollow and steam be lnade to circulate between the plates, or steam-pipes could be laid in the circular trough or bottom M. lt will be seen, too, that, as represented, the rotation of the pan causes the rollers to revolve. If desirable, independent driving apparatus could be applied to the rollers, so as to cause them to rotate at a different; surface speed to that ofthe pan. p

Having now described my invention, what I claim is- Dry ground or powdered caustic alkali, as herein described.

ln testimony of which invention I have hereunto set my hand.

WILLIAM J. MENZIES.

Witnesses: l

LIsLE S'roKEs, R. S. CHILD, J r.

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