SU737753A1 - Unit for thermal treatment of finely disintegrated material - Google Patents

Description

(54) INSTALLATION FOR HEAT TREATMENT OF DISPERSIBLE

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The invention relates to the heat treatment of materials and can be used in metallurgy, construction and other fields of technology.

Currently used kilns and installations for firing, as a rule, produce high-quality firing of the material only in cases where the size of its fractions fluctuate in a small range. The lime entering the lime kiln has polydisperse fractions in its composition, most often, from 0 to 5 mm, so before loading it into the kiln plants it should be divided so that fractions with a small dispersion of dispersion come to the kiln. The operation of dividing the material requires additional labor, financial and time costs. Loading the polydispersed lime fractions into the kiln plant may lead to deterioration of the product quality, primarily due to uneven calcination. In addition, a significant amount of the most finely divided limestone is carried away with the gas in a reduced form. MATERIAL

A limestone calcining plant is known, which is a vertical kiln, to the lower part of which channels from gas furnaces are connected, which includes a device that feeds a fine fraction and separates an air inlet shaft. The loading device for feeding coarse fractions of the material to be calcined is located above the furnace and is connected to the upper part of the last channel, and the place of flow of gas is located below the place

10 supply of the fine fraction of the material to be calcined by Cil

The disadvantage of the dZhI device is that it completely eliminates the possibility of uniform processing of large and small fractions of the material, since the small fraction immediately goes into the gas stream with the highest temperature and moves with it in a flow that creates real conditions fractions.

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Closest to the proposed invention in terms of the technical solution and the effect achieved is a plant for burning raw cement material, comprising a heater for preheating the material, made in the form of three cyclone-separators sequentially interconnected, roasting shaft furnaces and rotary kilns. The material is preheated by exhaust gas coming from the fourth cyclone (standing at the exit of the shaft furnace), which serves to separate the flue gases and material burned in the shaft furnace, before it is fed into the rotary kiln. The complex of heating cyclones is connected to the furnace with a channel for feeding material into the furnace for firing. The channel is brought from above. A flue is also connected to the upper part of the furnace chamber, which connects the furnace with chipspone, which is connected in turn with a channel with a rotating furnace and a flue pipe with a heater. The furnace of the shaft furnace is located in its lower part. Pipeline for gas supply to the furnace under pressure is slightly below the burners. The loading is carried out by the gravitational method 2. Such an installation, which offers a preliminary three-stage heating of the entire calcined material, its two-stage calcination does not allow to burn the material, the dispersion of which has a large range, due to the fact that the fine particles are removed from the furnace instantly and are possible prolonged circulation in a closed contour cyclone - rotating furnace - the upper part of the saddle furnace, a large fraction falls to the bottom half-burned, accumulating there: it is not necessary in the work; its layout is complicated. The heater of such an installation has a large hydraulic resistance due to the presence of a large number of pipelines, connecting nodes that lead to large hydro losses. Dusty heated air enters the Combustion furnace, which leads to stoppage and decommissioning. The purpose of the invention is to improve the uniformity of firing of large and small fractions. The goal is achieved by the fact that in the installation for heat treatment of dispersed material containing cyclones and a vertical kiln interconnected by means of ducts and nozzles for material loading and unloading devices, the furnace is divided into the upper chamber and lower chambers, each of which contains burners, One of the cyclones is made in two steps and is connected to the upper chamber of the fuser by nozzles for small and coarse fractions, while the other is connected to the lower chamber of the furnace, a flue gas duct. In addition, the installation is equipped with a gravitational trap installed on the flue duct coming out of a two-stage cyclone and connected to the burner devices of the upper and lower chambers of the furnace. The drawing is a schematic representation of the installation. The installation has a furnace 1, made in the form of two vertical mounted chambers of the upper and lower chambers, between which is located a diaphragm 1a, a two-stage cyclone 2, the lower chamber of which serves to separate the circular fraction, and the upper chamber to separate the fines fraction, the hopper 3, screw auger 4, cyclone 5, burner devices 6 and main flue 7 with gravity trap 8. Screw feeder 4 is connected to flue 9 leaving cyclone 5, branch pipe 10. Flue 9 is brought to the lower part of the lower chamber of a two-step cycle it is 2. The lower chamber of the cyclone 2 and its upper chamber are connected to the upper chamber of the furnace 1 by branch pipes, respectively, 11 and 12. The main gas duct 7 is attached to the upper chamber of the cyclone 2. To the upper chamber of the furnace 1 in its upper part and to the lower chamber in its the lower parts are tangentially burned by devices 6 connected by channels 13 to a gravitational trap 8 installed on the gas duct 7. Directly under the diaphragm 1a separating the upper and lower chambers of the furnace 1, there is a gas duct 14 connecting the furnace 1 with the cyclone 5. Unloaded burned places of the material are the lower parts of the cyclone 5 and the furnace 1. The nozzles 11 and 12 are equipped with hydraulic locks 15.,. The installation works as follows. From the hopper 3, the screw feeder 4 supplies the material through the pipe 10 to the gas duct 9, through which, together with the separating gas, flows into the gas chamber of the cyclone 2. In the chamber, a larger fraction of the material separates from the gas and through pipe 11 enters the furnace 1 The finer fraction of the material is from. The lower chamber is carried through the regulating slit 16 into the upper chamber of the cyclone, where the flow, unwinding and losing its speed, thus ensures the possibility of separating the smallest fraction. During the residence of the material in the cyclone 2, it is heated. Separated from the fine fraction through the tube 12 enters the furnace 1. The separated cooled gas from the cyclone separator enters the flue 7. The gas supplied tangentially from the burner 6 located in the upper part of the furnace 1 unwinds the calcined material, thus extending its time

roasting. The steam traps 15 do not allow the gas to flow through the nozzles 11 and 12, and its flow, passage through the diaphragm, is directed to the gas duct 14, and from there to the cyclone 5. The smallest fraction is removed from the furnace together with the gas. In cyclone 5, the fine fraction is separated, collected in its lower part, from where the load is generated. The larger fraction, continuing its movement down the lower chamber, is subjected to further calcination due to the additional heat from the burners 6 installed in the lower part of the lower chamber. The larger the fraction, the larger the way down it makes 1. Then, a part of the entrainment material of which, through the gas duct 14, the energy of the gas flow is sufficient, rises up and enters the cyclone 5, and the removal of the heaviest particles occurs through the discharge port 17 in the lower part of the lower chamber of the furnace 1. Several required reduce the temperature of the combustion products supplied from the burners 6 to the furnace 1. This provides for a considerable amount of cooled gases through the channels 13 from the main gas flue 7.

The application of the proposed plant allows to ensure uniform firing of the material, the degree of dispersion of which varies in a large range, eliminating the final firing step. The uniformity of the calcination degree is increased to 85%.

The presence in the installation of a two-stage cyclone in the path of the exhaust gases ensures the separation of both large and small fractions of the material, sufficiently cleansing gases. Supplying the flue with an additional gravity trap reduces the percentage of material carried away by the pelvis by 5-10%,

Injection of lawn flue burners provides a reduction in the temperature of the combustion products, eliminating the burnout of the material being burned, at the same time

m SNN; 1 specific heat consumption. The burners work on pure gas.

Conducting a separate discharge of the coarse and fine fraction makes it possible to select the mode in the cyclope in such a way that the quality of cleaning is high and to do with only one step of oshstka.

Yes1P1a installation, which allows to burn the material, the degree of dispersion of which varies in a large range, reduces the cost of firing due to jCKnip4eHHK operation of dividing it into several parts with varying degrees of dispersion.

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Claims (2)

1. Installation for heat treatment of dispersed material containing cyclones and a vertical kiln, United by means of flues and pipes for a gmersha, loading and unloading device, which is characterized by the fact that, in order to increase the uniformity of firing of large and small fractions, the furnace is divided into upper and lower chambers, in each of which burner devices are installed, one of the cyclones is made in two stages and connected to the upper chamber by branch pipes for small and coarse fractions, and the other is connected to the lower Lechi chamber by a tangential gas duct. 2. The installation according to claim 1, that is, with the fact that it is equipped with a gravitational trap installed on the duct coming out of a two-stage cyclone and connected to the burner devices of the upper and lower chambers of the furnace. Sources of information taken into account during the examination 1. USSR author's certificate N ° 95113, cl. F 27 B 15/00, 1953. No. 1423875, 2. Patent UK cl. F 4 V, pub. 1976. On the cleaning process