SU1755023A1 - Apparatus for production of metallurgical lime - Google Patents

Abstract

The invention relates to the building materials industry and makes it possible to increase the operational reliability of the unit. For this, the furnace is loaded from the hopper, the lime lock passes through the sealing valve, the discharge is carried out through the discharge table into the crusher and then into the chute, the cross-sectional area S and height H of which are determined from the dependencies. P / S (5.6-13) -103; H - 1.25 -10s (P / S) 2, where P is the aggregate capacity. 3 il.

Description

The invention relates to a technique for the endothermic burning of lumpy carbonate rocks, for example, limestone, and can be used in the metallurgical, chemical and construction sectors of the industry.

The purpose of the invention is to increase operational reliability.

Figure 1 shows the assembly layout; figure 2 - unloading unit assembly, a longitudinal section; FIG. 3 shows the dependence of the height and diameter of the gate-discharge chute on the speed of lime in it and the productivity of the furnace,

The unit for the production of metallurgical lime contains a douhisht pr - winding and countercurrent furnace with mines 1 and 2, in which the material is heat treated. Loading of limestone and the furnace is carried out from the loading hoppers 3 through the sluice bunker 4 6 of the furnace shaft. The furnace is constantly under pressure because, thanks to

sealing valves 5-7 the depressurization of the furnace at the time of loading does not occur.

Lime is discharged using an unloading device 8 (for example, an unloading table) directly into the crusher 9, where the grinding of the material takes place. The discharge and discharge flow 10 is intended for unloading the crushed lime to the consumer.

The cross-sectional area and estrus height are determined by dependencies:

P / S- (5.6-13) -103; H 1.25 -108 (P / S) 2, where P is the unit capacity, tons / day;

S — estrus section area, m2;

H - the height of the heat, m

The unit for the production of metallurgical lime works as follows.

The limestone to the conditional size (the ratio of the diameter of the minimum pieces to the diameter of the maximum is 1: 4) is loaded by the feeder into the "&

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The hoppers 3. The sealing valves 6 and 7 are closed, the valves 5 are open. After the hoppers 3 are filled, the sealing valves 5 are closed. The mines are loaded immediately after switching the gas flows by opening the valves 6 and 7, B 1) limestone is burned, the air supplied to the combustion is heated; in the countercurrent shaft 2, limestone is preheated and partial dissociation of limestone occurs.

The cooled lime through the discharge device 8 is continuously supplied for crushing to the crusher 9, where it is crushed to a size that corresponds to the upper limit of the requirements of steelmaking. Then, through the unloading shut-off chute 10, the lime is transported by the conveyor to the lime sorting compartment. Sealing the bottom of the furnace is carried out by a barrier layer of crushed NOR material in the discharge and shut-off chute 10, which provides the required gas tightness without sealing valves and special seals. The inclusion of the crusher directly into the furnace circuit eliminates additional overloads, which lead to abrasion of the material, an increase in energy consumption for transportation, and a decrease in the yield of conditioned lime. It is preferable to use a rotary crusher, which also determines the minimum abrasion of lime during the grinding process. In addition, unit downtime is excluded due to the gas-tightness of the bottom of the kiln and the need to replace seals, which also lead to a loss of productivity and a decrease in the yield of conditioned lime,

It has been established experimentally that the lime sink rate at the discharging point should not reach a value of 120 mm / s, at which the mode of unrelated movement occurs and spontaneous gathering of material and depressurization of the furnace can occur. Taking into account possible inhomogeneities of the material movement and on the basis of the condition of complete exclusion of the mode of uncoupled motion, the design descent rate should be no more than 50 mm / s.

Fig. 3 shows the dependence of the P / S complex on the descent rate (WGX) of the material; the intersection of the dependence with the abscissa, corresponding to a speed of 50 mm / s, gives the maximum value of the P / S complex, amounting to 13 -103,

Fig. 3 also shows the dependence of the height of the barrier layer, which provides the necessary gas density of the lower furnace, on the P / S complex. The dependence was obtained by studying the resistance of a layer of lime with a particle size of 20-40 mm in the presence of lime with a particle size of less than 20 mm and an amount of 10%, The maximum possible height of the locking layer from the layout expediency is 4 m. The intersection of the abscissa corresponding to the specified height, with the functional dependence AND f (P / S) and the ordinate axis gives the minimum value of the P / S complex equal to 5.6 - 103.

Fig. 3 also shows the dependence of the diameter of the chute (D, mm) on the P / S complex, poi of various furnace capacities for the limits of the P / S complex (5.6-13) -103. If the value of the P / S criterion is greater than 13-10, the descent rate exceeds 50 mm / s and a sufficient margin is not provided to prevent the possibility of spontaneous descent of lime and depressurization of the furnace. When the P / S criterion is less than 5.6–103, the height of the discharge stop flow exceeds 4 m, which is impractical from the point of view of the furnace layout, leads to an increase in the total height without improving the operational reliability indicator, and the energy costs associated with lime transportation increase When choosing the geometrical parameters of the discharge shut-off chute, the P / S complex values should be chosen in the specified range. For example, the value of the P / S complex is chosen to be 7-103, then the height of the discharge-shut-off chute, providing the necessary sealing of the bottom of the furnace, is 2.6 m, while the diameter of the chute, determined by the P / S complex, is 150 t / day 165mm, with a capacity of 300 t / day 230 mm, with a productivity of 600 t / day 335 m.

8, the proposed furnace design provides the necessary sealing at any furnace capacity, eliminates dusting in the unloading device, and therefore eliminates the need for an aspiration system, eliminates additional abrasion of lime and energy consumption associated with unloading and transporting lime for crushing, eliminates downtime of the furnace associated with violation of the tightness of the bottom of the furnace. The absence of the discharge drum as a whole reduces the metal structure and simplifies its operation.

Claims (1)

Invention Formula An aggregate for the production of metallurgical lime, containing a two-shaft continuous-flow counterflow regenerative kiln with loading and unloading units, sealing devices and a crusher, characterized in that, in order to increase operational reliability, The crusher is placed between the unloading unit and the sealing device, made in the form of a discharge-zagorny estrus, while the cross-sectional area and the height of the estrus are determined by the dependencies: P / S (5.6-13) - 103; H 1.25 -108 (P / S) 2, where P is the capacity of the unit, tons / day; S — estrus section area, m2; H - the height of the heat, m S & Phia.1 m w sh FIG. 2 SO 200 40 60 tfa, Mrt / c Sh Zhv D, &&