SU903682A1 - Unit for heat treatment of fine material - Google Patents

Description

(54) INSTALLATION FOR HEAT TREATMENT OF DISPERSE MATERIAL

one

The invention relates to a technique for heat treating a material and can be used in metallurgy, construction, and other fields of technology.

Limestone, in particular for agglomeration production, is crushed before firing up to a maximum value of 3 mm. Current furnaces and kilns for dispersed materials have a number of drawbacks.

The lime kiln plant is known to contain a vertical kiln, to the bottom of which channels from the gas fireboxes are connected, a device that supplies the fine fraction and a branch shaft for supplying air. A loading device for feeding coarse fraction of the material to be calcined is located above the furnace and is connected to the upper part of the latter channel, and the gas supply is located below the point of supply of the small fraction of the material to be calcined 1.

A disadvantage of this device is the uneven processing of the large and small fractions of the material, since the small fraction immediately enters the gas stream with the highest temperature and moves

with him in the flow, which creates real conditions for overfilling the small fraction.

The closest in technical essence to the present invention is an installation for the heat treatment of a dispersed material,

 containing a furnace divided by a diaphragm into upper and lower chambers, in each of which burner devices are installed, one of the cyclones is two-stage and connected to the upper chamber

10 furnaces for fine and coarse fractions, and another (cyclone precipitator) is connected to the lower chamber of the furnace by a tangential gas duct. A gravitational trap is installed on the flue duct coming out of a two-stage cyclone, connected to the burner-shaking devices of the upper and lower chambers of the furnace. This installation provides for firing of small fractions and preheating of large fractions in the upper cyclone chamber and the subsequent additional processing of large

20 fractions in the lower conical chamber 2. However, the specific heat consumption for the upper cyclone chamber is almost two times larger than for the lower one, due to the need to heat a large fraction of the material. In connection with the entry of both fine and coarse fractions into the upper cyclone chamber at the same time, the plant capacity for the finished product is actually halved, since the weight concentration of the material should not exceed a certain maximum for the cyclonic process.

In addition, a disadvantage is the low heat utilization of the high temperature flue gases leaving the furnace. Moreover, the cyclone-precipitator, connected directly to the lower chamber, should have high heat-resistant properties.

The purpose of the invention is to reduce the specific heat consumption per unit of production.

This goal is achieved by the installation of heat treatment of dispersed material containing interconnected gas ducts and nozzles two-stage cyclone and cyclone precipitator, a vertical furnace divided into upper and lower chambers, the burner is installed in the lower chamber, and the upper chamber is connected by coarse fraction with a two-stage cyclone, loading and unloading devices, equipped with a cyclone installed between the upper and lower chambers with a burner device that connects nen nozzle for fine fraction with a two-stage cyclone, and a cyclone precipitator is connected with the upper chamber tangential gas flue.

The drawing shows schematically the installation.

The installation for heat treatment of dispersed material contains a kiln made in the form of the upper chamber 1 and lower chamber 2 interconnected by a cyclone 3. Burners 4 are tangentially mounted in the lower part of chamber 2 and in the cyclone 3, chamber 1 in the upper part is connected by a tangential gas duct 5 with a cyclone precipitator 6, the exhaust duct 7 of which is connected to the lower part of the lower chamber 8 of a two-stage cyclone, and the upper chamber 9 is connected by a duct 10 to the cyclone 11 after-treatment of waste flue gases. The material to be processed from the hopper 12 is fed by the feeder 13 through the nozzle 14 to the duct 7, through which it enters a two-stage cyclone. From the lower chamber 8 of the two-stage cyclone, a large fraction of the nozzle 15 is directed to the upper conical chamber 1, and the small fraction through the nozzle 16 From the upper chamber 9 of the two-stage cyclone and the lower part of the cyclone after treatment I, enters the cyclone 3. The burnt coarse lime fraction is unloaded from the lower part of chamber 2 via the nozzle L7, and the fine lime - from the cyclone precipitator 6 through conduit 18.

The installation works as follows.

From the feed hopper 12, the feeder 13 supplies material through the nozzle 14 to the duct 7, through which the flue gases are transported to the lower chamber 8 of the two-stage cyclone. In chamber 8, the coarser fraction is separated from the flue gases and through pipe 15 enters the upper chamber 1. The smaller fraction of the material is carried from the lower chamber 8 to the upper chamber 9 of the two-stage cyclone, where the smallest fraction of material is separated. The flue gases from the upper chamber 9 through the duct 10 are fed to do0 cleaning into the cyclone I. The fine fraction of the material from the upper chamber 9 and the cyclone 11

through pipe 16 enters the roasting into the cyclone 3 due to the tangential entry of high-temperature flue gases from the burner 4. The fired small fraction of the material with the flue gases of the cyclone 3 and the lower conical chamber 2 enters the upper chamber 1. As a result, large fractions of the material entering in chamber I, due to heat exchange

0 in the ascending swirling flow of waste flue gases and the fired fines are heated and then fed to the firing in the ascending swirling flow of the heat carrier of the lower chamber 2, in the lower part of which the combustion products from the burner 4 are unloaded tangentially. Unloading the burnt coarse material is produced in the lower part of chamber 2 through nozzle 17. Cooled flue gases and small fraction

the material from chamber 1 through the tangential gas duct 5 enters the cyclone-precipitator 6, a small fraction of the material from which is discharged through pipe 18, and flue gases are discharged through the gas duct 7.

Thus, when only a small fraction of the material is fed into the cyclone chamber 3, the fuel consumption for its firing decreases, and the coarse fractions are heated in the upper conical chamber 1 due to the heat of the exhaust flue gases, thereby improving their heat use, while reducing flue gas temperature allows the use of less heat-resistant materials for the cyclone precipitator.

The invention makes it possible to reduce the specific heat consumption per unit of production by heating a large fraction with flue gases, and the fact that only a small fraction of the material enters the cyclone chamber reduces the consumption of natural gas.

Claims (1)

Invention Formula Installation for heat treatment of dispersed material containing interconnected gas ducts and nozzles two-stage cyclone and cyclone precipitator, vertical furnace divided into upper