RU2196012C2 - Method of size air-separation of finely dispersed loose materials and device for method embodiment (versions) - Google Patents

Abstract

FIELD: construction, ore mining and abrasive material industries. SUBSTANCE: method includes disintegration of material, size separation in ascending air flow of fine and coarse fractions. Circulation fraction is separated by sifting in the form of oversize product from separated or foreign materials sizing above 1 mm. Coarse fraction is separated in the form of undersize product of separated material as final product. In return, circulation fraction is dosed in definite volume and fine fractions of separated material is sucked out of disintegration zone by pulsing flow. Method is realized with the help of device versions for air separation by size of finely dispersed loose materials in which disintegration chambers are made either vibrating with special step grid feeding by funnel, sieve mounted in lower part of screen, air interrupter, or made with rotor, with perforated blades attached to needles at an angle to shaft axis with blades fastened over circumference at a distance from one another to chamber internal side. EFFECT: higher efficiency . 3 cl, 5 dwg

Description

 The invention can be used in the construction, mining, abrasive industries.

 Known gravity pneumatic classifier, including pnevmosh-htu, equipped with inclined overflow devices, which are made in the form of a set of plates installed parallel to each other with longitudinal slots, feeder, fan, cyclone and containers for collecting fractions.

 It was supposed to increase the efficiency of separation (classification) in this apparatus by pouring material from shelf to shelf.

 The disadvantage of this classifier is the high turbulence of the upward air flow with particles of the separated material in the pneumatic shaft due to the presence of the said plates in its cross section, which created harmful turbulence and dead zones that prevent a clear separation of fine particles by size. To separate fine particles by size, laminar flows are necessary. It is impossible to create them in this device (SU 988364 A, B 07 B 4/02, 01/15/1983).

 Another technical solution that is close in function is the gravity classifier, similar to the previous one, overflow shelves in which are connected to the walls of the pneumatic charge by means of elastic hinges, which makes it possible for the shelves to oscillate under the influence of air flow, which increases the harmful turbulent flow to an even greater extent. aggravating the process of separation of particles by size (SU 1281313 A, B 07 B 4/02, 01/07/1987).

 The closest technical solution known is the method of air separation of finely dispersed bulk materials by size and a device for its implementation, including disintegration of the material, separation of particles by size in an upward flow of air with the allocation of small and large fractions, separation of the circulating fraction from the separated material, feeding the circulating fraction together with the separated material into the disintegration zone in a closed cycle in the required ratio. The device includes a disintegration chamber with a rotor, a feeding funnel, an outlet window for a large fraction and an outlet window for the exit of an air stream with fine particles into a vertical channel, an air intake nozzle, an air supply device (RU 2132242 C1, 07 V 7/083, June 27, 1999).

 The disadvantages of this method and device are that the circulating fraction is formed from a dust-gas mixture of medium-sized particles, the low accuracy of separation of fine particles by size and low intensity of disintegration.

 The aim of the present invention is to increase the efficiency of separation of fine particles by size by improving conditions and increasing the intensity of disintegration.

 This goal is achieved due to the fact that in the method of air separation of finely dispersed bulk materials by size, including disintegration of the material, separation of particles by size in an upward air flow with the separation of small and large fractions, separation of the circulating fraction from the separated material, feeding the circulating fraction together with the separated material into the disintegration zone in a closed cycle in the required ratio, the circulating fraction is isolated by sieving in the form of an oversize product from of a vaporized material or foreign material with a particle size of more than 1 mm, while a large fraction is isolated in the form of an under-sieve product of the separated material as the final product, and when returning, the circulation fraction is dosed in a certain volume, while small fractions of the separated material are sucked out of the disintegration zone by a pulsating air flow.

 The method is implemented on the installation options for air separation of finely dispersed bulk materials by size, consisting of a vertical separation channel connected to a disintegration chamber, an air supply device made in the form of a fan, the disintegration chamber is made vibrational and contains a stepless grating, at the upper end of which is installed a funnel for feeding it, and a sieve is mounted in the lower part of the lattice to separate the circulating fraction from the sublattice product and the material to be separated, the device is equipped with an air chopper connected at the inlet to the disintegration chamber to create air pulsations and prevent secondary formation of particle aggregates in the disintegration chamber and the separation channel, a hopper and a dispenser for regulating the circulation volume, and a transport device for transporting the circulation fraction to the disintegration chamber in a closed loop.

 Another variant of the device for air separation of finely dispersed bulk materials by size, consisting of a disintegration chamber with a rotor, a feeding funnel, an outlet window for a large fraction and an outlet window for the exit of an air stream with thin particles into a vertical separation channel, nozzles for air intake, devices for feeding air, and the rotor is made with perforated blades mounted on the spokes at an angle to the axis of the shaft for the gradual movement of a large fraction to the exhaust window, while on the inner side of the disintegration chamber at a distance from each other circumferentially fixed blades, wherein the apparatus is provided with air interrupter.

 This goal is achieved due to the fact that the known method of separating fine particles by size in a vertical air flow is supplemented by a set of actions, the order of their implementation and the conditions for implementation, which are as follows / Fig. 1, 2 /.

 In FIG. 1 shows a diagram of the proposed method in the area of disintegration of the separated material in the first stage of separation by size.

 In FIG. 2 shows schematically a device for implementing the proposed method.

 In FIG. 3 shows a cross-section along aa of the separation channel with dampers.

 Figure 4 shows a cross section along BB of another embodiment of the device for the proposed method.

 Figure 5 is a longitudinal section along aa of the same device.

 The method of air separation of finely dispersed bulk materials by size is as follows.

 A circulation fraction is prepared from a separated or foreign solid material, for example, from quartz sand or abrasive with a particle size of more than 1 mm; load the capacity of the hopper 11/2 / circulation fraction, set the dispenser 12 volume of circulation. In the vertical separation channel 1, from the side of its upper end, rarefaction of air is created by the fan 2 so that the air is sucked through its lower slice, forming an upward flow, then the air flow is interrupted periodically by the chopper 9 at the suction with a predetermined frequency that is regulated, thereby creating a pulsating flow in the vertical separation channel 1. This action reduces the likelihood of aggregates in the separation channel, which increases the separation efficiency.

 Next, the average velocity of the upward pulsating flow in the separation channel 1 is set equal to the speed of the boundary grain so that the particles are separated by the size of a given size, the speed of the upward flow is controlled by the throttle 15. Then the separated material is fed by attaching it to the circulation fraction in the receiving funnel 5 The material is fed from the funnel in a uniform flow into the disintegration chamber, where it is disintegrated, destroying aggregates and aeroflucules from fine particles under the action of m of high-frequency impacts of chamber 3, lattice 4 and mechanical interaction / impacts, friction / with particles of the circulation fraction, while fine particles are pulsed by a stream of pulsating air into separation channel 1, where the final separation of particles by size occurs: fine particles are carried upward and downward by air flow they are precipitated in sedimentation chambers 16, 17, and large ones, together with particles of the circulation fraction, are sieved on sieve 7, which is a continuation of the woodless lattice 4 and has cells larger than large fraction of the material to be separated, and smaller than the circulation fraction, thus separating a large fraction of the material to be separated in the form of an under-sieve product of the material to be separated as a final product from the circulation fraction released in the form of a sieve product, which is returned to the disintegration chamber in a closed cycle by means of the vehicle 13, which is equipped with the device.

 Experiments show that the process of disintegration (destruction of aggregates, aeroflocs) involving particles of the circulation fraction in it proceeds much more efficiently, thereby increasing the efficiency of particle size classification.

 The described method of air separation of finely dispersed bulk materials by size is implemented by the device.

 The specified technical result is achieved by the fact that the device (Fig. 2, 3) contains a vertical separation channel 1, the upper cut of which is connected to the fan 2, and the lower is connected to the disintegration chamber 3, inside of which is mounted a stepless grating 4, consisting in its upper part from the receiving funnel 5, where the source material and the circulation fraction are fed, in the middle part - from steps 6, by means of which the material is weighed, evenly distributed over the entire cross section of the chamber and disintegrated by This means that intense impacts of the lattice with a high frequency and mechanical interaction of the particles of the circulation fraction and the separated material, and sieve 7 in the lower part of the lattice, by means of which a large fraction is separated, are performed.

 The adjustment of the speed of the upward flow in the separation channel 1 is performed by the throttle 15.

 Fine particles are precipitated by known cyclone type 16 devices, fine particles are filtered 17. The air flow in the separator is created by a fan 2. The separation channel 1 is cleaned of fine particles settled on its walls by a periodic vibration method, for which the separator is equipped with a separate vibrator 18. If dividing channel 1 of a relatively large cross-section, then turbulence forms in the vertical air flow, to eliminate them, “dampers” 19 are inserted in the form of vertical cross sections rod / 3 / cylindrical or other section.

 The presence in this device / air separator / disintegration chamber 3, grilles 5, 6 screens 7 of a chopper 9, an elevator 13, a hopper 11, a dispenser 12, a granular agent - a circulation fraction, their functional relationships create favorable conditions for the destruction of aggregates of fine particles, and prevent secondary their formation in the separation chamber 1, and the presence of dampers 19, the shape and articulation of the structural elements together create optimal aerodynamic conditions for the implementation of the proposed method with comparative high efficiency.

 Another embodiment of the device is distinguished by the design of the disintegration chamber / Fig. 4 /, which includes a housing 1, equipped with a feed funnel 2, an exhaust window 3, an air suction nozzle 4 and a window 5 for the air flow in the mixture with fine particles into the separation channel. A rotor 6 with blades 7 is installed in the cavity of the housing 1 in bearings at its end faces. The blades are perforated and fixed on the spokes at an angle to the axis of the shaft for the gradual movement of a large fraction to the exhaust window 3 of the housing 1. At the same time, on the inner side of the disintegration chamber from a friend around the circumference are fixed blades. When the rotor rotates, the blades disintegrate the material, break up aggregates of fine particles and weigh them in the intake air stream. The remaining nodes and parts and their functional relationship are similar to the previous version of the device.

 The experiments showed that the proposed invention improves the efficiency of separation of fine particles by size by improving conditions and increasing the intensity of disintegration.

Claims (3)

 1. The method of air separation of finely dispersed bulk materials by size, including disintegration of the material, separation of particles by size in an upward flow of air with separation of small and large fractions, separation of the circulation fraction from the separated material, feeding the circulation fraction together with the separated material to the closed loop disintegration zone in the required ratio, characterized in that the circulating fraction is isolated by sieving in the form of an oversize product from the separated material and foreign material with a particle size of more than 1 mm, while the coarse fraction is isolated in the form of an under-sieve product of the separated material as the final product, and when returning, the circulation fraction is dosed in a certain volume, while small fractions of the separated material are sucked out of the disintegration zone by a pulsating air flow.  2. A device for air separation of finely dispersed bulk materials by size, consisting of a vertical separation channel connected to a disintegration chamber, an air supply device, characterized in that the air supply device is made in the form of a fan, and the disintegration chamber is made vibrational and contains a stepless wireless a grate, at the upper end of which a funnel is installed to feed it, and a sieve is mounted in the lower part of the grate to separate the circulating fraction t of the under-sieve product of the material to be separated, the device is equipped with an air chopper connected at the suction to a disintegration chamber to create air pulsations and prevent secondary formation of particle aggregates in the disintegration chamber and in the separation channel, a hopper and a batcher for regulating the volume of circulation, and a transport device for transporting the circulation fraction closed-circuit disintegration chamber.  3. A device for air separation of finely dispersed bulk materials by size, consisting of a disintegration chamber with a rotor, a feeding funnel, an outlet window for a large fraction and an outlet window for the exit of an air stream with fine particles into a vertical separation channel, an air intake nozzle, a device for feeding air, characterized in that the rotor is made with perforated blades mounted on the spokes at an angle to the axis of the shaft for the gradual movement of a large fraction to the exhaust window, with that on the inner side of the disintegration chamber at a distance from each other circumferentially fixed blades, wherein the apparatus is provided with air interrupter.

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