RU2238497C1 - Rotating furnace for thermal treatment of materials - Google Patents

Abstract

FIELD: rotating furnaces for roasting.

SUBSTANCE: the rotating furnace for thermal treatment of materials has a chamber in the form of an expanded part of the connection shaft under the rotating furnace, with an inclined bottom installed across the shaft opposite the furnace, and a platform under the shaft to feed material to the cooler. A pipe-line is laid to the chamber, it is connected to the air blower. The side walls of the connection shaft in the lower part are made inclined and their footings are positioned above the side edges of the platform for feeding of material to the cooler. The platform is made as a trolley connected through a link to the crank mechanism of the drive.

EFFECT: reduced consumption of fuel and enhanced capacity of the furnace.

3 cl, 2 dwg

Description

The invention relates to devices for heat treatment of materials and can be used, for example, for calcining limestone, dolomite, calcining coke, sintering alumina-containing, cement mixtures and other materials.

Known rotary kiln for calcining limestone containing a connecting shaft with a drum refrigerator (see book. A.V. Monastyreva "Production of lime", M .: Higher school, 1978, p.162). The disadvantage of the furnace is the increased specific fuel consumption for firing due to the low degree of use of heat of lime for the firing process.

Known rotary kiln containing its connecting shaft with a refrigerator, in which there is a chamber for holding the material before it enters the refrigerator (see AS No. 1315769, MKI 4 F, 27 No. 38). In this furnace, a slight decrease in specific fuel consumption for heat treatment is achieved by improving the quality of the calcined production.

Known rotary kiln, taken as a prototype, in the connecting shaft of which with a refrigerator also has a camera and perforated partitions beneath it (see AS No. 1481576, MKI 4F, 27 V 7/06). The camera is made in the form of a vertical rectangular hopper with a cone-shaped bottom, one of the walls of which is connected to the rod for regulating the size of the discharge outlet. The camera is equipped with a layer level sensor. Partitions are located in the shaft at an angle to its axis. The width of the partitions is ~ 0.5 of the width of the shaft, with each partition relative to the other mounted on the opposite wall of the shaft.

A rotary kiln operates as follows.

The calcined material from the rotary kiln enters the chamber, the residence time in which is regulated by the layer level sensor, and is discharged through the hole by opening the outlet in the conical bottom by moving its movable wall by means of a traction. The material, descending down the inclined partitions of the connecting shaft, is cooled by the air that is sucked through the refrigerator using a baking smoke exhauster, and enters the drum refrigerator. Heated air from the mine is sent to a rotary kiln to burn fuel.

Disadvantages of the furnace:

- low degree of heat utilization of the calcined (calcined) material for the heat treatment of the material in the rotary kiln due to the short residence time of the material on the partitions and the ineffective organization of heat exchange between air and material on the partitions (heat from the material to air is transferred mainly from the open surface of the material to partitions);

- increased hydraulic resistance of the air associated with the device in the mine partitions and zigzag air movement in the mine;

- the impossibility of cooling large-sized materials (sintered pieces of material of large sizes) due to their occurrence on partitions.

All this limits the possibility of reducing specific fuel consumption for heat treatment of materials and increasing the productivity of a rotary kiln.

An object of the invention is to reduce specific fuel consumption for heat treatment of the material and increase the productivity of a rotary kiln.

The technical result is achieved in that in a known rotary kiln containing a connecting shaft with a drum cooler and a chamber in the shaft, the latter is made in the form of an expanded part of the connecting shaft under the rotary furnace, against which an inclined hearth is installed across the shaft, and a platform under the shaft for feeding material into a refrigerator, while a pipe connected to the air blower is brought into the chamber. The side walls of the connecting shaft are made inclined, and their bases are located above the side edges of the platform for supplying material to the refrigerator. The platform is made in the form of a trolley connected by a rod with a crank drive mechanism.

The above solution allows us to simplify the design of the chamber in the mine. The expansion of the connecting shaft under the rotary kiln allows you to increase the volume of the chamber and, as a result, increase the residence time of the material before it enters the refrigerator. The installation of an inclined hearth across the shaft against its expanded part ensures the flow of material poured from the rotary kiln into the expanded part of the shaft, and the installation of a platform with a device for feeding material into the refrigerator under the shaft ensures the creation of a dense layer of material in the chamber and its supply to the refrigerator.

The supply of the pipeline to the chamber, connected to the air blower, allows you to organize the cooling of the material with air in a dense layer, as the most effective heat transfer between the cooling air and the material. The execution of the side walls of the connecting shaft inclined and the location of their base above the side edges of the trolley ensures the flow of material directly to the site. A platform with a device for feeding material into the refrigerator in the form of a trolley connected by a rod with a crank drive mechanism is the simplest in design and reliable in operation.

Figure 1 shows a longitudinal section of a rotary kiln 1 with a connecting shaft 2 and a drum refrigerator 3 when the refrigerator is located under the furnace, and figure 2 is a section along aa.

The connecting shaft below the furnace is expanded and an inclined hearth 4 with a support 5 is installed in it. The side walls 6 in the lower part of the shaft are made inclined. Under the shaft in front of the drum refrigerator, a trolley 7 is mounted, supported by rollers 8 on the rails 9 and connected by a link 10 with a crank mechanism 11 of the drive. A conduit 12 is connected to the chamber, connected to an air blower, and the chamber is equipped with a layer 13 level sensor. A conduit 14 is installed to discharge air from under the inclined hearth.

A rotary kiln operates as follows.

After heat treatment in a rotary kiln, the material is poured along an inclined hearth 4 into the extended part of the connection shaft onto the carriage 7 and, falling down due to its movement by the carriage into the loading neck of the refrigerator, is cooled by air, which enters the layer through the pipe 12. The layer height in the shaft is maintained by the level sensor layer 13 by changing the length and number of strokes of the cart. Heated air from the layer through the top of the expanded part of the shaft and through the pipe 14 enters a rotary kiln for burning fuel. The final cooling of the material is carried out in a drum refrigerator due to the leakage of air through it and partial irrigation of the refrigerator body with water.

The implementation of the proposed material cooler will allow, as calculations show, to reduce the specific fuel consumption for heat treatment of the material by at least 7-10% and increase the productivity of rotary kilns by the indicated values.

Claims (3)

1. A rotary kiln for heat treatment of materials, comprising a connecting shaft with a drum cooler and a chamber in the shaft with a device for supplying material to the refrigerator, characterized in that the chamber is made in the form of an expanded part of the connecting shaft under the rotary kiln, against which an inclined hearth is installed across the shaft, and a platform under the shaft for supplying material to the refrigerator, while a pipe connected to the air blower is connected to the chamber. 2. The rotary kiln according to claim 1, characterized in that the side walls of the connecting shaft in the lower part are inclined and their bases are located above the side edges of the platform for supplying material to the refrigerator. 3. The rotary kiln according to claim 1 or 2, characterized in that the platform for supplying material to the refrigerator is made in the form of a trolley connected by a rod with a crank drive mechanism.

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