US1067686A

US1067686A - Method for slaking lime.

Info

Publication number: US1067686A
Application number: US67215312A
Authority: US
Inventors: Walter Schulthess
Original assignee: Individual
Current assignee: Individual
Priority date: 1912-01-19
Filing date: 1912-01-19
Publication date: 1913-07-15
Anticipated expiration: 1930-07-15

Description

W. SCHULTHESS. METHOD FOR SLAKING LIME. APPLICATION FILED JAN.19,1912.

1,067,686. Patented July 15, 1913.

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WALTER SCHULTHESS, OF PARIS, FRANCE.

METHOD FOR SLAKING LIME.

Specification of Letters Patent.

'Application filed January 19, 1912. Serial No. 672,153.

To all whom it may concern Be it known that I, WVALTER SciiuL'ri-mss, a citizen of the Republic of Switzerland,

residing at Paris, France, have invented new and useful Improvements in Methods for Slaking Lime; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

It has previously been proposed to conduct steam containing powdered lime, into water, said lime-containing steam resulting from slaking lime in vertical chimneys, to the axis of which is admitted the slaking water. By a series of conically shaped funnels mounted in the chimney this lime-containing steam is alternately distributed and collected, being exposed to a water spray, and the product is used again to slake new charges of lime. Experience has proven that no satisfactory cleansing of the steam can be obtained thereby. Also, under the best conditions, it is impossible to condense, by the quantity of water necessary to slake a given quantity of lime during a definite period of time, even one-half of the steam produced during the slaking operation, and without condensing the steam carrying the powdered lime, it. is impossible to completely precipitate the lime. These conditions are caused by the steam entering the chimney at a very high temperature. To cool the steam to condensation, a quantity of water becomes necessary which considerably exceeds the quantity of water necessary for slaking. Moreover, the lime water produced by the complete transformation of the powdered lime contained in the steam will be transformed into a lime-paste, which because of its physical qualities can not be conducted onto the lime to be slaked.

According to .my invention, steam containing powdered lime, produced by slaking a definite quantity of lime, hen leaving the slaking apparatus is conducted through a preferably horizontal channel, in which the greater portion of the powdered lime, by reason of the specific weight of the lime, is precipitated in the form of a drypowder, and the temperature of the steam is lowered so much that by a following treatment with well distributed water it is instantly con-- doused, so that a complete precipitation of all the lime-powder contained in the steam is secured. Byt-he device hereinafter described a heating of the slaking water to 180 F. is also obtained for continuousworking, which much accelerates and improves the process of slaking.

In the accompanying drawing a device for carrying out my invention is illustrated by way of example.

Figure 1 shows a longitudinal section Patented July 15,1913.

through the device. Fig.' 2 a longitudinal section through a portion of the same, drawn to a larger scale. Fig. 3 is a cross-section on line A-A of Fig. 2. Fig. 4 is a longitudinal section through another illustrative embodiment of the discharge end of the device. Fig. 5 is a front elevation showing the device illustrated in Fig. 1.

To irrigate the-lime to be slaked there is provided a pipe 3 which extends to the interior of the retic-ulate drum 2. The drum is supported at one end by the reticulate cross 4 provided with a long nave mounted on a shaft 25. At the other end, the drum rests on rollers 5 mounted inside the mantle of the slaking-vessel. The rollers 5 are guided in a furrow 6, Fig. 3, provided on the mantle of the reticulate drum. The shaft 25 is disposed in the axis of the slaking-vessel 23 and carries mixing and conveying blades 22. The slaking vessel is surrounded by a steamjacket 24:. The reticulate cross t is provided with holes 21 through which the parts of the charge which cannot be slaked, as parts of unslaked lime and stones, in the slaking vessel may be forced out.

To the vertical chimney 8 is connected one end of a horizontal channel 17 to the other end of which is connected a chimney 9 of a larger diameter than the channel 17, and inside, in the axis of the chimney 9, are mounted a number of spraying nozzles 11. The nozzles 11 are fed by a pipin 12 carrying water under high pressure, w ose atomized discharge is dispersed in the chimney 9 as a fine mist. The channel 17 is also provided with a downward extending branch 18 with a closing device or valve 19 for its opening, under which a receptacle, as a each 20, for instance, can be arranged.

A large portion of the lime-powder con tained in the steam is precipitated in the channel 17 and may be collected in the sack 20. This lime-powder forms ahydrate of lime which is very pure and finely dispersed.

The steam escaping from the slaking vessel through the chimney 8 which still contains lime-powder, after its temperature is considerably lowered, is forced to pass through the mist which is formed in the chimney 9 by the nozzles 11, and condensed, and at the same time freed from the lime-powder. The water flowing downward on the walls of the chimney 9 is converted into lime-water and flows into a channel 9 from whence it is led back by the pipe 3 into the slakingvessel to be used as slaking water for new quantities of lime. The quantity of water entering by pipe 12 is regulated so that the quantity of water flowing out of the nozzles during a definite period of time is exactly sufiicient to slake the quantity of lime introduced in the slaking device during the said period of time. By applying a horizontal channel 17 of a suitable size, all lime-powder can be precipitated and converted into a thin lime vater. A large portion of the heat of the steam produced by slaking is transferred to the slaking water discharged from the nozzles 11, and the water is thus heated to about 160 F. This is very important, because some kinds of lime can only be slaked with warm slaking-water.

In the illustrative embodiment shown in Fig. 4, a heavy angle iron 13 is provided at the discharge end of the slaking-vessel. The angle iron maintains on the bottom of the vessel a layer of slaked lime in the form of lime-Water and at a certain level, while the excess flows out. Pieces of unslaked lime and foreign materials are stopped by the angle iron and scooped up by cups l t mounted on the shaft 25, from which they are thrown on an inclined discharge plate 15. An opening 16 is provided in the bottom of the vessel, and this opening, which is closed while the apparatus is in operation, serves for completely discharging the apparatus when desired.

In order to avoid rapid wear of the reticulate device, the reticulate drum may be made of perforated sheets, instead of wiregauze. In this case, the thickness of the sheet must be such that the vibrations caused by the rotation of the reticulate drum, will prevent the choking of the latter. The

sheets are suitably made from 0.08 to 0.5

inch thick, according to the nature of the lime to be slaked and the size of the apparatus.

In carrying out my improved method, the lime to be slaked is filled into the reticulate drum 4 to which slaking water is admitted. A preliminary slaking is thus produced, which is continued in the slaking vessel 23. The steam produced, carrying the heat and lime powder originating from the slaking process, is conducted through the horizontal channel 17 in which the greater portion of the lime powder is precipitated as a consequence of the rapid cooling of the steam. The cooled steam is then conducted to the chimney 9 and into the path of the water used for the slaking process, and is condensed in the form of lime-water, which is used to slake new quantities of lime.

I claim- 1. Method for slaking lime, which consists in filling lime into a slaking vessel, admit-ting Water to the vessel, mixing the water and lime, conducting the steam produced carrying heat and lime-powder into a cooling channel in which the greater portion of the lime-powder is precipitated in form of dry powder and the temperature of the steam is lowered, exposing said steam to finely dispersed Water, and leading the resulting water containing some lime into the slaking vessel containing new quantities of lime to-be slaked.

2. Method for slaking lime, which consists in slaking lime with water, conducting the resulting steam carrying lime-powder into a horizontal cooling channel in which the greater portion of the lime-powder is precipitated in the form of dry powder and the temperature of the steam is lowered, exposing said steam to finely dispersed water and using the resulting water containing some lime for slaking fresh quantities of lime.

In testimony that I claim the foregoing as my invention, I have signed my name in presence of two subscribing witnesses.

WALTER SCHULTHESS.

Witnesses:

ALPHONSE LoUIs. SToFFEL, H. C. Goxn.