RU2056178C1 - Whirling dust collector - Google Patents

Abstract

FIELD: chemical engineering. SUBSTANCE: whirling dust collector insludes cylindrical housing with axial inlet and exhaust pipes, dust trap, cylindrical penetrable insertion equipped with blades. The insertion is made as two sections. The blades of lower section are set up at positive angle of attack to tangential constituent of velocity vector od secondary external flow. The blades of upper section are mounted at negative angle of attack to tangential constituent of velocity vector of secondary flow. EFFECT: enhanced efficiency of gas cleaning from dust. 4 dwg

Description

 The invention relates to dust-cleaning equipment for cleaning gases from dust under the action of centrifugal force, under the influence of which suspended particles are discarded on the inner surface of the apparatus and settle, and can be used in dry filters in the mining, energy and other industries.

Known vortex dust collectors for dry gas cleaning, containing a cylindrical body with a hopper, nozzles for primary and secondary gas supply, a swirl, shielding permeable insert of a cylindrical shape, which can be made with holes inclined in the direction of rotation of the gas stream [1] or with circular peripheral outlets dust and gas mixture [2]
However, these device designs have a significant drawback: there is a rebound of dust particles from the wall of the housing, which negatively affects the separation coefficient and separation ability of the apparatus.

Also known is a vortex dust collector containing a cylindrical body with axial inlet and exhaust pipes, a pipe for secondary gas supply, a dust collector, a shielding insert with slots overlapped by the plates, a swirler installed in the inlet pipe [3]
However, the presence of an insert with slots intersected by plates significantly increases the resistance of the apparatus and, consequently, increases energy costs. Radial jets that occur during operation of the apparatus destroy the tangential swirling secondary flow, which reduces the efficiency of the apparatus. In addition, this swirler is distinguished by the complexity of the design, the complexity of manufacturing and installation.

 The basis of the present invention is the task of creating such a vortex dust collector, which would improve the dust collection efficiency over the entire height of the apparatus, reduce aerodynamic drag, energy consumption for the exhaust fan drive, would be simple in design.

 The problem is solved in that a dust collector is proposed comprising a cylindrical body with axial inlet and exhaust pipes, a nozzle for introducing a secondary gas flow, a dust collector, a cylindrical permeable insert provided with blades, in which according to the invention the insert is made in the form of two sections, and the blades of the lower section are installed at a positive angle of attack to the tangential component of the velocity vector of the secondary (external) flow, and the blades of the upper section are set at a negative angle of attack to the tangential th vector component of secondary flow.

 The guide vanes of the lower section of the cylindrical permeable insert, installed at a positive angle to the tangential component of the velocity vector of the secondary (external) flow, increase the peripheral speed of the internal flow in the lower part of the apparatus.

 The guide vanes of the upper section of the cylindrical permeable insert, installed at a negative angle of attack to the tangential component of the external flow velocity vector, create the effect of ejection of solid particles from the peripheral layer of the internal flow to the external.

 The proposed vortex dust collector will ensure an efficient vortex of both gas flows, prevent the rebound of solid particles and reduce the possible occurrence of side vortices that impair the aerodynamics of the apparatus.

 In FIG. 1 shows a General view of the device; figure 2 is a view along arrow A in figure 1; figure 3 section BB in figure 1; figure 4 section BB in figure 1.

 A counterflow swirl dust collector includes a vertical cylindrical housing 1. Inside the housing 1, a cylindrical permeable insert with movable blades is installed, made in the form of two sections 2. The blades of the lower and upper sections are set to the required angle simultaneously using a drive ring fixed by a lock screw. Inside the housing there is also a nozzle 3 for the primary gas flow with a displacer 4. At the bottom of the housing there is a tangential nozzle 5 for supplying the primary gas flow, at the top of the housing there is a tangential nozzle 6 for supplying the secondary flow. The outlet of the purified gas is carried out through the exhaust pipe 7. To reflect the secondary swirling flow, a retaining washer 8 is installed, for collecting dust the dust collector 9.

 A dust catcher with an oncoming swirling stream works as follows.

 The dusty gas stream is fed through the tangential pipe 5, where it, having passed through the pipe 3 with the displacer 4, is twisted and enters the inner space between the blades of the lower section of the cylindrical insert 2. Here, due to the action of the displacer 4 with the cowl, the dusty gas stream forms a cone expanding upward. The secondary gas flow entering through the tangential pipe 6 forms a wall flow directed downward towards the internal flow.

 From an external stream, dust particles under the action of centrifugal force are thrown to the walls of the apparatus and rush to the lower part of the apparatus. The guide vanes of the lower section of the cylindrical insert are set at a positive angle of attack to the tangential component of the external flow velocity vector and contribute to an increase in the tangential component of the internal flow, which leads to an increase in dust collection efficiency.

 The remaining part of the secondary gas in the lower part of the apparatus, reflected from the retaining washer 8, passes into the internal stream, thereby increasing its swirling speed. Under the action of centrifugal force, dust particles from the internal stream are thrown to the blades of the cylindrical insert, fall into the inter-blade space and rush downward under the action of the secondary flow in the lower section of the insert.

 The guide blades of the upper section of the insert are set at a negative angle of attack to the tangential component of the external flow velocity vector and create the effect of ejection of solid particles from the peripheral layer of the internal flow to the external, which provides a high degree of gas purification, which is removed from the dust collector through the exhaust pipe 7.

 The trapped material through the gaps formed by the retaining washer 8 and the housing 1 is removed into the dust collector 9. The slope of the retaining washer 8 is selected not less than the angle of repose of the material.

 The main advantage of the proposed device compared to the known ones is that a cylindrical permeable insert made in the form of two sections with movable blades mounted at different angles of attack relative to the tangential component of the secondary velocity vector is installed between the exhaust pipe and the primary flow pipe in the housing of the proposed device (external) flow, which prevents the rebound of particles from the inner walls of the cylindrical body to its center, enhances the vortex of the primary o (internal) stream, creates the effect of ejection of solid particles from the peripheral inner layer of the stream in the upper part of the apparatus, which provides a high degree of gas purification from dust particles.

Based on laboratory tests performed on the model at a gas velocity of 5 m / s in the apparatus, the optimal installation angles of the blades of a cylindrical permeable insert are 7 9 ^° . At other angles of installation of the blades of the upper and lower sections of the insert, parasitic vortices appear, which impair dust separation and increase the aerodynamic drag of the apparatus. The fractional composition of dust was 0 6 μm 42.7 5 10 μm 16 10 15 μm 9.3 15 20 μm 6 20 25 μm 7 more than 30 μm 19
With these parameters, the degree of gas purification from dust was 98.7
In practice, the optimal blade angle can be determined experimentally depending on the gas velocity in the apparatus and the fractional composition of the ablation.

Claims (1)

 Vortex dust collector, including a cylindrical body with axial inlet and exhaust pipes, a pipe for introducing a secondary gas stream, a dust collector, a cylindrical permeable insert equipped with blades, characterized in that the insert is made in the form of two sections, and the blades of the lower section are set at a positive angle of attack to the tangential component of the velocity vector of the secondary external flow, and the blades of the upper section are set at a negative angle of attack to the tangential component of the velocity vector of the second stream.

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