RU2753111C2 - Vane axial radial separator - Google Patents

Abstract

FIELD: separators.

SUBSTANCE: vane axial radial separator with a rotor and a rotation drive, installed in a shell surrounding it in a mine, for example, a power boiler in front of an economizer in a gas-ash mixture flow. Wherein, the separator contains packages of hollow blades in the amount of at least two in each package, the blades contain an internal ash-collecting channel, which is formed by an upper wall perpendicular to the axis of rotation, and a lower wall attached to the first wall along the leading edge at a small angle of attack, and on the trailing edge of the lower wall of the blade there is a groove in the form of a square bent over the upper wall of the blade in the direction of rotation of the package, and at the ends of the ash-collecting channels on the blades there are slots that are located opposite the slots made in the ash-collecting channels in the shell, and the area of the blades in each package does not exceed the area occupied by pipes in the first row of the coupled heat exchanger. The ash-collecting scrapers on the trailing edge of the blades are located along a trajectory similar to the trajectory of movement of solid particles under the action of centrifugal and karyolis forces. Packages of blades are installed sequentially one above the other and rotate in opposite directions. The separator has an even number of blade packages on the rotor, which are rotated in opposite directions. The shell of the confuser-diffuser form with internal cavities, with ash conveyors and inside it is connected to the external ash-collecting network of the boiler, and the conveyors have vibration generators, accelerators for pumping separated ash. The rotor and the conveyor of the separator have rotation drives of the electric, electromechanical, pneumatic or hydraulic types and can be located outside the shell of the separator.

EFFECT: vane axial radial separator operation improvement.

5 cl, 3 dwg

Description

The invention relates to inertial vane apparatus, which are used in heat power engineering and can be used in boiler plants operating on fuel with abrasive ash.

The invention according to the description for the AC No. 1442808 A1 from 09.01.87 [1] relates to heat power engineering and allows to increase the reliability of the protection of the coils of convective heating surfaces from eolian wear. The device contains a central perforated sheet, placed between the groups of coils. On both sides of the sheet, the main and additional gratings are fixed, located perpendicular to the plane of the sheet. Grids of the same name are located symmetrically relative to the plane of the sheet, with the main grids being placed between adjacent coil packs, and additional grilles - between the bends of opposing coil packs.

Also known device, see the description of the invention AC 1558440 from 02.11.87, [2] the purpose of which is to reduce hydraulic resistance and energy costs, increase the efficiency of dust collection. The rotor rods are hollow with holes in the stern with respect to the direction of rotation of the part of the cross-section and in the end part facing the impeller installed on the side adjacent to the fan on the rotor. When the rotor and wheel rotate, dusty gas drawn into the chamber swirls around the rotor. The resulting field of centrifugal forces throws particles away from the axis of rotation, and the cleaned gas passes between the rods, between the blades of the fan wheel and enters the consumer. The rotation of the impeller makes it possible to suck through the holes of the rods the boundary layer of gas with dust particles, which through the end holes enter the impeller blades and are thrown out again into the separation zone.

The dust separator according to the description of the invention to the AC No. 598623 dated 06.21.76 [3] works as follows. Contaminated air enters through a tangential connection in the housing. When moving along the spiral channel, suspended particles under the action of centrifugal force are thrown to the wall of the housing, due to which layer-by-layer air cleaning occurs. In this case, the most clean air will be the air flowing along the louver and bypassing it with a very small angle of attack (the angle between the direction of air movement and the plane of each plate), which leads to an increase in the cleaning efficiency in the apparatus.

To keep the preset speed of the contaminated air constant, a spiral guide is attached around the louvered grill, which is a continuation of the cover and is made with a variable pitch. Up to 85% of clean air is discharged through the louver grill, and up to 15% of the air is directed through the branch pipe, taking with it the bulk of the separated dust, which then goes to the additional ash separation. Another dust collector according to the invention AC 1210881 from 08.12.82, [4] operates as follows. Dust-laden gas entering the rotor under the action of a vacuum created by a fan wheel, twisted by the rotor. Dust particles are thrown away from the rotor under the action of centrifugal forces, and the cleaned gas is sucked into the rotor and discharged to the consumer through the scroll. When approaching the rotor, the peripheral gas velocity Ug changes according to a complex law, reaching at the level of the outer surface of the rotor a value equal to the peripheral speed of the latter. At the level of the upper edge of the inlet end of the fan wheel blade, the circumferential speeds of the wheel Uc and the gas flow Ug are practically equal to each other. However, along the radius (at the entrance section), these velocities change according to different laws: the circumferential speed of the wheel - according to the law of rotation of a rigid body, the circumferential velocity of the gas is practically constant, since the swirling energy received from the rotor does not have time to dissipate under the action of friction forces: the gas is constantly sucked out of the rotor at a speed W.

As a result, there is a difference between the circumferential speeds of the gas wheel Ug - Uk = U, which increases as it approaches the shaft. The angle of attack of the incident flow with respect to the plane of the fan blades, which is practically zero at the upper edge, increases with increasing U, which leads to the appearance of separation zones in the interscapular space of the wheel. The efficiency of the dust collector is sharply reduced, the risk of surging increases (the fan characteristic becomes steeper), and pulsations of the gas flow occur. This reduces the efficiency of dust collection, as the flow of gas and particles is more turbulized and the particles are more difficult to separate.

These are analogs.

Their common disadvantage for installation in the limited dimensions of existing boilers are large dimensions, large hydraulic resistance of the gas-ash mixture flowing through the gas duct of the boiler and the complexity of the design, except for the analogue according to AC No. 1442808 A1 dated 09/01/87 [1] loading cycles, and low efficiency of the ash protection device.

Also known is a dust collector fan, according to AC 523989 from 06/17/1974, [5], including a housing, an impeller with a disc, a perforated shell and a water supply pipe, enclosed in a mesh cylindrical droplet generator. The droplet generator is connected to the impeller disk with the possibility of joint rotation, inside which a water supply pipe is located. A mesh shell is installed inside the casing, and a hole for sludge discharge is made in the casing of the dust collector fan. The selected device [5] is the closest prototype analogue to the claimed device.

The dust collector fan works as follows.

The dust-laden air flow is sucked into the dust collector fan, where water jets from the branch pipe through the slots enter the rotating cylindrical mesh droplet generator and spray onto the droplets. The water-air mixture passes into the working cavity of the dust collector, where the formed droplets come into contact with dust particles. Moistened dust particles and water droplets are thrown by the impeller blades onto the mesh shell, where they are collected. Sludge and dust fall behind the mesh shell and are removed from the dust collector.

The disadvantage of the known device is the insufficient efficiency of dust collection, the complexity of the design and the need to use water, which cannot be used in heat-stressed boiler structures.

Analogs and selected prototype.

1. AS No. 1442808 A1 dated 09/01/87

2. АС 1558440 dated 02.11.87

3. AS No. 598623 dated June 21, 1976

4. АС 1210881 from 08.12.82

5. АС 523989 dated 06/17/1974

The technical result achieved by the claimed invention consists in creating dynamic stability and braking the ash flow flowing into the heat exchanger, separating a significant part of the abrasive ash, increasing the manufacturability of installation and maintainability if it is necessary to replace the ash protection elements of the vane axial radial separator without destroying the pipes of the coupled heat exchangers.

The invention is illustrated by drawings, which do not cover and, moreover, do not limit the entire scope of the claims of this technical solution, but are only illustrative materials of a particular case of implementation:

FIG. 1 Device top view.

FIG. 2 The device is a side view and in section along the section AA in FIG. 1.

FIG. 3 A blade of the device with a flap, cross-section B-B in Fig. 1

Description of the claimed invention

A vane axial radial separator 1 with a rotor 2 and a rotation drive 3, with a transmission shaft 4, is installed in the surrounding shell 5 in a mine, for example, in a power boiler in front of the economizer in the flow of a gas-ash mixture 6, contains packages of hollow blades 7 in an amount of at least two in each package, the blades contain an internal ash collection channel 8, which is formed by an upper wall perpendicular to the axis of rotation and a lower wall 9 attached to the first wall along the leading edge at a small angle of attack, and a groove 10 in the form of a square is made on the trailing edge of the lower wall of the blade , bent over the upper wall of the blade in the direction of rotation of the package, and on the tips of the ash collection channels on the blades there are slots that are located opposite the slots made in the ash collection channels 11 in the shell, moreover, the area of the blades in each package does not exceed the area occupied by the pipes in the first row coupled heat exchanger. In the inner cavities, the shell has ash-collecting channels 11 with ash conveyors 15 inside them.

As an embodiment of the claimed device, the ash-collecting chute on the trailing edge of the blades is made along a trajectory similar to the trajectory of movement of solid particles under the action of centrifugal and karyolis forces, and the blade packs are installed sequentially one above the other. To ensure minimum aerodynamic losses, the shell can be given a cone-diffuser shape.

The vane axial radial separator acts as follows: the flow of the gas-ash mixture 6 flowing through the inlet confuser of the shell 5 enters the blades 7 of the upper package and the ash (solid) fraction under the action of centrifugal forces is carried away along the ash-collecting chutes 8 into the slot in the shell 14, enters the channels into shell 15 and then fed by conveyors to the ash collection network 12 of the boiler. The gas flows around the blades 1 and is accelerated by the lower wall of the blade, installed at a small angle of attack to the oncoming gas-ash flow, and moves to the associated heat exchanger, for example, the boiler economizer, thus restoring the velocity head of the incoming heat carrier flow in front of the heated surface of the heat exchanger in the convective parts of the boiler, and the local hydraulic loss of the velocity head is compensated for when flowing around the blades of the axial-radial separator. The separation effect increases significantly if the packages with blades are installed in a pyramid one above the other, and the blades in adjacent packages rotate in opposite directions. This is determined by the geometry and dimensions of the free zone not occupied by the heat exchanger in the convective part of the boiler.

Sources of information

1. AS No. 1442808 A1 dated 09/01/87 Μ Cl ⁴ . F28G 15/10. A device for protecting the coils of convective heating surfaces from eolian wear.

2. АС 1558440 dated 02.11.87 Μ cl. В07В 7/083. Rotary dust collector.

3. АS No. 598623 dated 06.21.76, M. Cl. ^2. В01D 45/00. Centrifugal inertial dust separator.

4. AC 1210881 from 08.12.82, M. Cl. F16L 58/04. Anti-corrosion device.

5. АС 523989 from 17.06.74, M. Cl. Ε21F5 / 20. Dust collector fan.

Claims (6)

1. A vane axial radial separator with a rotor and a rotation drive, installed in the surrounding shell in a mine, for example, a power boiler in front of the economizer in a gas-ash mixture flow, characterized in that it contains at least two hollow blade packages in each package, the blades contain an internal ash-collecting channel, which is formed by the upper wall, perpendicular to the axis of rotation, and the lower wall attached to the first wall along the leading edge at a small angle of attack, and on the trailing edge of the lower wall of the blade there is a groove in the form of a square bent over the upper wall of the blade in the direction of rotation of the package , and on the tips of the ash-collecting channels on the blades there are slots that are located opposite the slots made in the ash-collecting channels in the shell, and the area of the blades in each package does not exceed the area occupied by the pipes in the first row of the coupled heat exchanger. 2. A vane axial-radial separator according to claim 1, characterized in that the ash-collecting chute on the trailing edge of the blades is made along a trajectory similar to the trajectory of movement of solid particles under the action of centrifugal and karyolis forces. 3. A vane axial radial separator according to claim 1, characterized in that the packs of blades are installed sequentially one above the other and the separator has an even number of packs of blades on the rotor, driven in rotation in opposite directions. 4. Blade axial radial separator according to claim 1, characterized in that the shell has a confuser-diffuser shape with internal cavities, ash-collecting channels and ash conveyors, which are connected to external vibration accelerators for the movement of ash. 5. Blade axial radial separator according to claim 1, characterized in that the rotor and the conveyor have rotation drives of electric, electromechanical, pneumatic or hydraulic types and can be located outside the separator shell, and an ash-collecting collar is made on the fairing around the separator axis. 6. A vane axial radial separator according to claim 1, characterized in that the upper walls of the blades and ash-collecting chutes on the blades have surface compaction by quenching, nitrogenation, cementation or laser spraying of abrasion-resistant materials.

Images