SU1210032A1 - Installation for calcinating raw material mixture - Google Patents

Description

112

The invention relates to an industry carrying construction materials and can be used in the preparation of cement clinker.

The aim of the invention is to intensify the heat and mass transfer, increasing the productivity of the plant and its reliability.

Figure 1 shows the proposed installation, the overall look; figure 2 is the same, side view; on fig.Z - section aa in figure 2.

The raw material mixture firing unit in the heat transfer fluid includes a granulator 1, auger feeder 2, an electric furnace 3 consisting of crucibles k and a shaft 5 for pretreating the mixture made in the shape of a pyramid and located in the center of the crucibles D. 6 and dumpers 75 formed in the form of blades with slits. To cool the material, a cooler consisting of a short push-type cooler 8 and a drum cooler 9 is used.

There is a system 10 for utilizing the heat of waste gases, and a gas collector 11.

The installation works as follows.

The raw material mixture is fed to the pellet-torus 1, from where the pellets, as they are formed, enter the screw feeder 2.

In the inner housing of the screw feeder 2, the granules are subjected to intensive drying due to the use of heat from the exhaust gases coming from the system 10.

Intensification of drying the granules is achieved due to the fact that the coolant into the screw feeder 2 is supplied in three directions: along the branch from system 10 to the hollow shaft of the screw and then into the layer of granules; along the branch from system 10 into the internal volume of the screw feeder 2 and further into the layer of granules; on the branch of the system 10 for heating the housing of the screw feeder.

The frequency of rotation of the screw of the screw feeder 2 is controlled by drying rpaHyj over time, and the pitch of the screw determines the optimal volume of granules, at which the granules do not break down during

22

due to their own weight, which reduces the dust emission.

The amount of air required for drying the granules is provided by system 10, which is equipped with an integrated fan unit with an adjustable rotational speed of the blades.

Next, the pellets are fed by a screw feeder 2 into the shaft 5, which, with the aim of

eliminating arching, is pyramid-shaped. In the crucible .4 and in the shaft 5 there is a metal melt, the temperature of which is maintained at the level required for

high-quality roasting of the raw mix.

In the upper part of the shaft 5, in the area of the gas collector 11, the granules are subjected to partial decarbonization, and then pass through the layer

the melt in the mine 5, where their decarbonization ends. The final firing of the pellets is carried out in the melt of the crucible 4,

The height of the melt layer in the crucible 4 is set in accordance with the time required for the heat treatment of the raw mix and the completion of the clinker-forming processes. Since the specific gravity of the clinker is several times less than the specific gravity of the metal melt, the calcined granules are splatted onto the surface of the melt, from where they are removed with the help of dumpers 7, equipped with

blades with slots for melt flow. To ensure the normal operation of the diverters 7, a cooling system is provided. The releasers 7 direct the clinker into trays 6, through which it enters the refrigerator consisting of a short pushing type refrigerator 8 and a drum cooler 9 where the first and second cooling stages are carried out.

The air for cooling the clinker in the refrigerator 8 is supplied through pulsators. To use waste heat to dry the pellets, a system 10 using waste heat is connected to the refrigerator 9.

In the case of the refrigerator 8 there is a pipe to which a gas pipeline can be connected to use heat in the waste-heat boilers and further in heating systems, max.

3 1

The steam-air mixture formed during drying of the granules in the screw feeder 2, and the reaction gases from the shaft 5 through the gas collector 11 are removed from the system.

Dp of removal of the reaction gases from the crucible 4 of the electric furnace 3 provides a cap with a pipe to which a gas pipeline can be connected.

The use of the unit allows to increase the intensity of heat treatment of the raw mix due to the use of 75-85% of the heat of the exhaust gases, to increase the reliability of the installation

32

by reducing the possibility of weld formation during firing, locating the drive of the screw feeder i outside the high temperature zone where the mine is located in the center of the crucibles, the latter ensures uniform output of the pellets from the mine throughout the entire melt volume, as well as increasing the plant performance due to intensive drying in the area of the gas collector and in the upper part of the mine with a reduction in time for phase transformations during clinker formation.

{M.

Claims (1)

A RAW MIXING FIRING INSTALLATION in a liquid heat carrier, including a screw feeder, an electric furnace consisting of a crucible and a preliminary heat treatment shaft of the mixture, and a gas duct, are distinguished by the fact that, with the aim of intensifying heat and mass transfer, increasing the plant productivity and its reliability, installation equipped with a gas collector located between the shaft and the screw feeder, and the shaft for preliminary heat treatment is made in the form of a pyramid and placed in the center of the crucible, equipped with trays, and dumpers, mounted data in its upper part and made in the form of rectangular blades with slots. S and 1210032>