US1617137A - Rotary kiln for burning cement, magnesite, lime, and the like - Google Patents

Description

Feb. 8 1927.

H. STEHMANN ROTARY KILN Fon BURNING CEMENT, MAGNlzzsI'ra,` mms, AND THE LIKE Filed July s, 1925 Patented F eb. 8, l1927.

UNITED STATES PATENT' OFFICE.

HARRY STEHIANN, 0F BERLIN-HOHEHSCHONHAUSEN. GERMANY.

BOTAR' KILN FOB BURNING CEMENT, MAGNESII'E, LIME, AND THB LIKE.

Application tiled July .3, 1925, Serial No. 41,408, and in Germany Kay 20, 1922.

When rotary kilns are used for burning cement, magnesi, lime and the like/too4 favourably infiuenced as the consumption of coal is increased.

This invention has for its object to avoid this inconvenience by intimate] connecting with the revolving tubular k1ln-a device which ensures that, -in totally or partially neglecting the recuperation of the heat radiating from the material which has been burned, only the accurately regulated quantity of air is supplied to the rotary klln which is actually required for the burnmg process. n It has been found that heat-economical advantages may be obtained even without recuperation of the heat of the burnt material when the discharge of the rotary kiln is closed absolutely airtight and the kiln is worked with the smallest ssible quantity of air -regulated in accor ance with the material to be burned. The new working method may be applied to any kind of rotary kilns even if, owing to insuliicient building height, it should be impossible to insert a Cil coolingchamber. The invention is based on these considerations as, according to the invention, the less important advantage of the recuperation of the heat radiating from the' material which has been burned is entirely or partly abandoned and the more important heat-economical advantage is utilized which results from the working with accurately regulated minimum quantities of air for the minimum quantities of fuel required for the material to be burned, any prejudicial excess of air being avoided. Y Y

The rota-ry kiln is equipped, according to the invention with an airtightly-closing discharging device adapted to permit accurate adjustment of the rotary kiln for the admission of the actually required minimum quantity of air corresponding to the minimum quantity offuel. The usual means 4maybe provided eventually for the artificial cooling of the dischargingdevice. the required minimum quantity of combustion air being admitted into the rotary kiln above said discharging device.

l 'An embodiment of the invention is illustrated, by way of example, in the accompanyin drawmg which shows an improved rotary iln in longitudinal section.

' Thev rotary kiln a terminates at the discharge end 1n ahead piecev b which serves for closing and with which the airti htly lclosing discharging' device c'isonecte the latter of which may be cooled by air or wa`` ter in an .well known manner. The combustion air is admitted above the discharg-v ing device into the rotary kiln togetherwith the fuel through the pipe d and the pipe e is used to introduce additional air which serves to regulate the. air admission to the minimum quantity required. It will be noted that .the ypipe e discharges. into the head b which has an air-tight connection with the kiln a above the discharge devices c, but below the discharge or lower end of.. .Y

the rotary portion c of the kiln'. AThis air is heatedby the cement clinker as it falls to the devices c which, as previously de-4 scribed, prevent the passage of a current of air up t rough them when they are opened todischarge their contents. The air lfor both the fuel feeding and the auxiliary combustion air is supplied by blowers or fans f.

I claim: n

A rotary kiln fonburning cement, magnesite and lime, inclu-ding a rotary inclined body portion, a head at the lower end thereof,an air-tight dischargepdevice directly connected to the lower end of said head and l meansto admit fue] to said head and body portion, in combination with an air supply .Y pipe arranged in the hea-d to direct a current HARRY STEHMANN.

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