SU1722621A1 - Separator for powdered materials - Google Patents

Abstract

This invention relates to the separation of fine powders into coarse and fine fractions. The goal is to increase the separation efficiency. The separator includes coaxially mounted cylindrical conic housings with convex lids reversed by convexity towards each other, located one above the other with the formation of a separation chamber, rotary vanes. The separator is provided with additional convex covers, and the main convex covers are made with annular slits, additional covers are installed on the outer side of the separation chamber with the possibility of overlapping annular slots and facing away from the separation chamber, and in the lower part of the additional cover there is an annular slot. 1 ill., 1 tab. cl

Description

The invention relates to devices for the separation of fine powders into large and small fractions, namely centrifugal separators, and can be used in the mining, construction, chemical and other industries.

A separator for powdered materials is known, which includes coaxial cylindrical-conical bodies with flat and slightly cone-shaped caps, a flow curler with rotating vanes located between the bodies, a loading nozzle, a nozzle for the fine fraction and gas, and large-sized discharge pipes.

The disadvantage of the design is relatively low, the separation efficiency due to the fact that in the vortex separation zone between the lids the gas velocity distribution is such that there is a wide range of sizes of equilibrium particles, the largest of which rotate in a circular trajectory at the periphery of the separation zone, and the smallest near the nozzle of the fines and gas (equilibrium trajectory - the circle along which the particle rotates with equal centrifugal force and aerodynamic drag force). The particles are displaced from the equilibrium trajectories in a random way under the action of turbulent pulsations and mutual collisions, and large particles can get into the small fraction, and small particles - into the large, i.e. particles whose sizes lie in a wide range between

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particles with equilibrium peripheral and inner radii of the separation zone do not have a predetermined output into their fraction, which leads to a low efficiency of the process.

The closest to the invention is a separator for powdery materials, including coaxially mounted cylinder-conical bodies with convex lids facing each other, forming a separation chamber, placed between the bodies with a swirling vanes, loading pipe, pipe for discharging fines and gas and discharge pipes of a large fraction,

Increasing the separation efficiency is achieved by gradually narrowing the height of the separation chamber to the axis due to the convexity of the covers, which leads to a narrowing of the width of the spectrum of the sizes of equilibrium particles that are indifferent to exit into their fractions.

The disadvantage of the design is the limited separation efficiency, due to the fact that together with a decrease in the width of the spectrum of the size of the equilibrium particles, the stability margin of their movement along the equilibrium trajectories and inertial escapes of large particles to the axis result in their falling into the outlet pipe of the fine fraction and gas, . contamination with large particles;

The purpose of the invention is to increase the separation efficiency by reducing the passage of large particles into the fine fraction.

Achieving this goal is determined by the creation in the separation chamber of a zone with a sharply increasing flow of a twist that beats the coarse fractions.

Achieving this goal is ensured by local expansion of the separation chamber and its subsequent contraction. When expanding the flow cross section, the circumferential gas velocity does not change or varies slightly, but the radial (flow) velocity drops sharply, resulting in a local increase in the flow swirl.

The goal is achieved by the fact that in the separator of powdery materials, including a craxially mounted cylinder-conical housing with convex lids facing each other, forming a separation chamber, placed between the hulls with a swiveler blades, a loading nozzle, a nozzle for removal of fines and gas and discharge pipes of coarse fraction, convex

the lids are provided with annular slots, fitted with upper and lower additional annular lids, convex outward from the separation chamber,

and at the base of the lower additional cover there is an annular slot.

The drawing schematically shows a separator for powdered materials, a longitudinal section.

0 The separator consists of an outer casing 1 with a convex lid 2 and an internal casing 3 with a convex lid 4. Between the convex lids 2 and 4 a separation chamber 5 is formed, and between the housings

5, a swirler 6 is placed. A feed inlet 7 is inserted into the outer case 1, and a discharging outlet 8 of the fine fraction and gas is connected to the convex cover 2. Both housings are equipped with unloading.

0 pipes 9 and 1.0 large fraction. In the lower convex lid 4 there is an annular slot 11, and in the upper convex lid there is a 2-annular slot 12, which are provided with additional lids 13 and

5 to 14, convex outward from the separation chamber 5, with an annular slot 15 at the base of the lower additional cover 13.

The separator works as follows.

The source material together with the gas is fed through the loading nozzle 7 into the gap between the housings 1 and 3, moreover, upon impact

5, the housing 3 is separated and discharged through the nozzle 1.0 the largest fractions. The remaining material, together with stasis, twists with a twister 6 and enters the separation chamber 5, in which, in a twisted state, moves to the axis towards the discharge pipe of the fine fraction and gas 8. The main part of the large fractions remains at the periphery and sediment5 the gap between the convex cover 4 and the housing 3, after which it is withdrawn through the pipe 9. Some of the large fraction of inertia moves to the axis of the separator. In the zone formed in the chamber 5 between the additional lids 13 and 14, a local decrease in the radial velocity of the flow occurs at an almost constant circumferential speed, as a result of which a local increase in the flow swirling occurs, causing a local increase in the relative level of centrifugal forces fractions. The small fraction together with the gas is discharged through the pipe 8. A small part of the sediment on the bottom

an additional particle cover 13 is discharged through the slit 15 to the nozzle 9.

The design efficiency was tested under bench conditions on a separator model with a diameter of 400 mm, with the separation of calcined petroleum coke with a median particle size of 60 µm. Experimental data are given in the table.

The limiting particle size in this separator is somewhat lower, since along with the beating of large fractions in the zone of local spin increase, small fractions are retained. Kpd separation increases slightly, but the degree of leakage of coarse fractions into a small product is substantially less (by 27%) in the proposed separator. The overall efficiency (separation sharpness) in this separator is 18% higher.

Thus, in the proposed separator, the separation efficiency is improved by reducing the inertial slip of large fractions into a fine product.

Claims (1)

Claims for powdered materials, including coaxially mounted cylindrical-conical bodies with convex lids arranged one under the other to form a separation chamber between them and facing each other convexly, placed between the cylindrical parts of the buildings a fluctuator with rotary vanes, a loading nozzle , a branch pipe for discharging the fine fraction and gas and a branch pipe for discharging a large fraction, located respectively in the upper and lower parts of the bodies; This means that, in order to increase the separation efficiency due to additional catching of large fractions, the separator is equipped with additional convex covers, the main convex covers are made with annular slots, and additional covers are installed on the outside the main ones with the possibility of overlapping the annular slots and are reversed by the bulge from the separation chamber; Separation characteristic Separator aeY number 629954 K.P.D. Breakthrough degree Granular separation size, µm Efficiency (sharpness) of separation (the ratio of the sizes of the fractions carried to the thin product by 75 and 25%) St. The proposed separator 0.83 0.24 23 0.45 0.53