SU63990A1 - Gypsum rotary kiln - Google Patents

Description

The essence of the process for producing stucco is the production of semi-aquatic from raw dihydrate gypsum. This dehydration process is carried out either by the “roasting or cooking” method.

In all existing installations for obtaining calcined gypsum, regardless of whether the coolant acts on the surface of the raw gypsum directly or through an intermediate body, uneven burning is always the case, since the pieces of raw gypsum, especially when they are more or less than large, from the surface they are burned, and in the core, they are left unburned, resulting in a non-uniform material of low quality.

To obtain a more uniform calcination, it is necessary that the pieces are as small as possible and that the calcination proceeds uniformly with intensive mixing of the material. These conditions are observed in a rotary kiln according to the basic author. St. N ° 29785, working by the method of "firing through the wall.

The best results are obtained in installations using the method of cooking, when the gypsum is kept in an atmosphere of water vapor, which softens the sharpness of the temperature difference between the coolant and the surface of the material being processed.

No. 63990-2 -

Even better results are obtained when the material is treated with water vapor of a superficial pressure, so the so-called "autoclaved gypsum has high strength.

The proposed gypsum kiln can combine work with an uninterrupted flow during high heat while maintaining the product to be treated in an atmosphere of water vapor at elevated pressure. This is achieved mainly by installing throttles in the nozzle, which removes water vapors from the furnace working space according to the main bus. St. No. 29785.

FIG. 1 depicts a longitudinal section of the furnace; FIG. 2 is a section along A-A in FIG. one.

The raw gypsum, crushed to a particle size of 5 mm, from a bunker / through a lock dosing unit 2 enters the screw 3, by means of which the drum 4 is continuously fed.

Passing through the inclined drum, the raw gypsum undergoes uniform dehydration and in the form of the finished product exits through the pipe 5.

The shutter 6 continuously releases material from the drum into the auger, which feeds it to the elevator for further shipment of silage, etc.

The hot gases produced in the furnace 6 pass along path 9, wash the drum from the outside and through channels 10, 11 enter the internal flue pipes 12, from which through the collector 13 through pipe 14 by means of a fan 15 are thrown into chimney 16.

The products of dehydration G emerging from the drum through the opening 17 as water vapor mixed with gypsum dust through a pipe fitted with a choke 18, enter the multicyclone 19, from which the deposited gypsum through the flashing light 21 through the pipe 20 enters the axial screw 7.

The density between the rotating drum and the fixed parts of the apparatus is achieved by means of sealing rings 22, which are attached to each other by the elasticity of the spiral springs. These rings are worn on the drum so that when it is extended from heating, they can move along the surface of the cylinder, remaining pressed under the action of springs.

The optimum vapor pressure inside the drum is set by the choke 18.

To adjust the speed of the dust-gas mixture in a multicyclone and to prevent steam condensation in it, some of the waste products of the combustion can be directed by means of a fan 15 and valve 15 to a pipe 19 to a multicyclone 19.

Internal flue tubes 12 are fixed in annular diaphragms 4 and the ends, and tightly embedded in holes made on the end sheets of the drum. These pipes have a significant heating surface and give the structure rigidity and bending strength. In addition, they promote good mixing of the material. On the inner surface of the drum along the entire length of the cylinder, ladles 12 are welded, the purpose of which requires no explanation.

Subject invention

Rotary kiln for gypsum burning by the author. St. No. 29785, characterized in that it is provided with a throttle installed in a nozzle, which drains water vapor from the working space and is intended to create pressure therein.

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