Centrifugal selective size grader of solid powders and method of its application

FIELD: process engineering.

SUBSTANCE: invention relates to selective sizing of solid powders. Proposed device allows to isolate substance fine and coarse fractions and comprises case, cylindrical vanes rotor accommodated there inside to run about its vertical axis, means to feed gas flow through vanes into rotor, set of vanes fixed inside said case and around said rotor and coaxially to allow the adjustment of their direction so that inlet gas flow can pass there through, initial material feed means, gas flow and captures fine substances discharge rotor outlet and means to collection of coarse substance not captured by gas flow which are located under said rotor. Said collection means comprises peripheral system with fluidised bed arranged around rotor axis A above at least said vanes and mid space between said vanes and rotor. Fluidising gas speed in fluidised bed horizontal cross-section is smaller than 1 m/s to repeat separation between fine and coarse substances. Note here that said fine substances return to mid position between said zones and rotor.

EFFECT: higher efficiency of separation.

18 cl, 5 dwg

The invention relates to a centrifugal device for selective granulometric separation of solid powdery substances, as well as to a method of using such a device.

A device of this type allows you to divide the flow of particles in the gas stream into two fractions: one small, smaller than the specified particle size, another large amount in excess of the specified grain size.

In the relevant field of technology, this device is also called a centrifugal air classifier".

The separation is carried out using a cylindrical rotor with a vertical axis, equipped with blades that are evenly distributed along the periphery, between which particles are opposite forces, that is, on the one hand, the centrifugal force created by rotation of the rotor and willing to discard these particles, and, on the other hand, taking the force of the flow created by the velocity of the gas, tending to the center of the rotor, which seeks to inspire them with him to the exit of the specified gas.

Thus, the centrifugal force will be greater for particles of larger size, and absorbs the force of the flow will be greater for particles of smaller size, which provides granulometric separation of the processed substances. Thus, material size, less the specified particle size separation, fond together with the gas to the exit of the specified gas, then as a matter of size, a large specified specified particle size, due to gravity fall down and are going.

Such high-efficiency separation devices are described in particular in documents FR 2642994 or FR 2658096.

Filing intended for processing substances can be run simultaneously through the upper part by gravity, and in this case, as a rule, the substances are dispersed rotating platform fixedly connected with the rotor, or suspended in the incoming gas, or by combining the two above mentioned ways.

In known devices, the collection of substances larger than the given particle size the size of the separation occurs through the hopper 5 in the form of an inverted cone located under the rotor. The walls of the hopper may have a large inclination relative to the horizontal, typically from 50 to 60° to ensure the passage of substances under the action of its own weight to the exit at the top of the cone. This slope determines the height of the cone of the hopper, which is a substantial part of the height of the device Assembly. Thus, the height of the hopper cannot be reduced, which can cause problems of its integration in some settings.

Furthermore, the design and dimensions of this Bunkyo the and require the location of the drive motor of the rotor at the top of the device. For this purpose, the output of the gas immediately made a knee to the drive motor rotor can be installed on this knee. However, this configuration assumes a sufficient length of the shaft rotation, connecting the engine and the rotor, so that he could pass through the knee. Within this tribe of shaft rotation must be protected pipe, special outer coating which should have abrasion resistance.

However, from the document GB 943722 known selector of the previous generation, made with the possibility of separation of powdery substances into two fractions: one small grain size and other large grain size, in which the collection of substances is provided by the collection system with a fluidized bed having a small slope, which reduces the height of the device.

Another disadvantage of devices of this type is that the separation between particles smaller or larger size is not ideal because of the small particle size, less than the given particle size, falls into the hopper along with the larger particles.

The flow of these small particles, cast together with the large substances, usually referred to as "bypass flow separation", and it is a disadvantage. The reason for this lack may be a group effect, to the torus fine particles, associated with the larger particles are rejected by the rotor, falling into the hopper, and poor feeding powdered substances into the device.

The present invention is the elimination of all or part of the above-mentioned disadvantages.

In particular, the object of the invention is to create a device and method that allows to reduce the bypass flow separation, i.e., the number of small substances, cast together with big substance.

Also object of the invention is to create a device granulometric separation with limited overall size height.

Also object of the invention is to create a device with a simplified architecture of the rotor drive.

Other objectives and advantages will be more apparent from the following description, provided as a non-limiting example.

The problem is solved in a centrifugal device selective granulometric separation of solid powdery substances made with the possibility of separation of substances into two fractions: fraction of small substances and a large fraction of substances containing:

- casing

a cylindrical rotor rotating relative to the specified casing around a vertical axis inside a specified enclosure, equipped with blades, distributed on the periphery specified what about the rotor,

means of submission specified in the casing of the gas flow entering into the specified rotor through these blades,

- a set of blades, relative to the specified internal casing and surrounding the specified rotor, a stationary relatively to the specified casing and, if necessary, regulated with the ability to change direction, arranged coaxially with the blades so that they could pass the specified incoming gas stream,

- money supply in the specified enclosure designed for sorting solids

- the rotor, with the specified output allows you to delete the specified gas stream and carried with him a small matter,

- gathering tools located below the rotor, not dragged by gas falling major substances.

According to the invention these tools contain peripheral fluidized bed, the layer which is located around the specified axis of the cylindrical rotor, at least under the said blades and the intermediate space, concluded between the said blades and the rotor, the speed of gas fluidization in horizontal section of the fluidized bed is less than 1 m/s to produce a new division between small matters and large substances, where these small substances on ravnayutsa back into the intermediate space between the blades and the rotor.

The object of the invention is also a method of using the device for granulometric separation in accordance with the present invention, in which the fraction of powdery substances are served in the specified casing between the vanes and the rotor device and share it with one hand on the small fraction of substances with a particle size lower than a given particle size, dragged the specified gas flow through the rotor to the output, in particular to the upper output device, and, on the other hand, a large fraction with a particle size exceeding a specified grain size, cast by the rotor in the direction of the collection device, according to the way average speed air fluidization in horizontal section of the fluidised bed set below 1 m/second, to minimize the emissions of the number of particles smaller than this specified particle size.

The invention will be better understood from the following description with reference to the accompanying drawings.

1 schematically shows a known device granulometric separation;

figure 2 shows the device granulometric separation in accordance with the present invention according to a variant implementation;

figure 3 schematically shows a device in accordance nastojasim invention according to the second variant of implementation;

figure 4 shows a graph showing known for the setup presented in figure 1, the degree of emission depending on the diameter of the particle;

figure 5 schematically shows a device in accordance with the present invention according to the third variant of implementation.

1 schematically shows a known device separation.

This device 1' includes a casing 6', inside of which around a vertical axis can rotate the rotor 2', equipped with blades 3' on its periphery.

A set of blades 7' surrounds the rotor 2' in front of the blades. Blades allow you to direct the gas flow in the direction of the blades 3' to the center of the rotor. The blades 7' is equipped with a rotary fingers along the vertical axis, providing the movement of the blades to control their orientation, in order to adapt the speed of the gases reaching the rotor to the rotational speed of the rotor.

Turning fingers all the guide vanes are connected with a single device that allows you to simultaneously send all blades at the same angle relative to the peripheral surface of the rotor.

The hopper 10'below the rotor and the blades of the device, provides for the collection of substances falling under the rotor, while the substances carried absorbed gases are removed through the outlet 9'.

This output is 9' immediately made elbow 90'that provides the set drive motor rotor over this knee. The shaft 21' of rotation of belonging simultaneously to the rotor and its drive (not shown), passes through the knee, inside of which he is protected by a pipe 22'.

The gas supply device passes through the casing 6'and through the vertical pipe 5', continuing the specified casing 6' down, covering the hopper 10'.

Intended to sort the matter may be submitted in suspension in the flow of the injected gas or you can enter through the top of the rotor at the level of the points 8' submission.

As shown in figure 1, in the known solution the hopper 10' has a height, which is decisive for the device and is part of the overall height dimensions. Furthermore, the presence of a bunker forced to install the actuator motor on the rotor 2'.

The object of the invention is a centrifugal device 1 selective granulometric separation of solid powdery substances, containing:

- casing 6,

a cylindrical rotor 2 rotating relative to the specified casing around a vertical axis inside the specified casing and equipped with blades 3, distributed on the periphery of the specified rotor

means of submission specified in the casing 6 of the gas flow entering into the specified rotor 2 through the specified blade 3,

- a set of blades 7 mounted stationary within the casing 6 and surrounding the rotor 2, is made, which, if necessary, with the ability to control its direction and located coaxial with the blades so that through them could be specified by the incoming gas stream,

- money supply in the specified casing 6 intended for sorting solids

output, in particular the upper output of the specified rotor 2, in particular located in relation to these funds flow of gas in such a way as to create an upward flow of gas within the specified rotor, with the specified exit 9 allows you to delete the specified gas flow, in particular the upward flow, and carried with him a small matter,

tools 10 collection, located below the rotor 2, for non-flowing gas falling major substances.

The fact that the blades 7 are stationary relative to the casing 6, means that they do not rotate with the blades 3 of the rotor. However, these blades are made with the possibility, if necessary, to change direction in order to adapt the velocity of the gas reaching the rotor to the rotational speed of the specified rotor.

For this purpose, the blades 7 can be equipped with rotary fingers along the vertical axis, while rotating the fingers all the guide vanes are connected with a single device that allows you to simultaneously focus all blades at the same angle relative to the peripheral p is the surface of the rotor.

According to the invention these means 10 collection include peripheral fluidized bed, the layer which is located around the axis And the specified cylindrical rotor 2, at least under these blades 7 and the intermediate space, concluded between the blades 7 and the rotor 2.

In addition, to reduce the bypass flow separation, the velocity of the gas fluidization in horizontal section of the fluidized bed provide less than 1 m/s, in particular in the range from 30 to 50 mm/s to produce a new division between small matters and large substances, where these small substances transported into an intermediate space between the blades 7 and the rotor 2.

As shown in the example in figure 2, the peripheral system fluidized bed may contain the tray 11, which forms the peripheral corridor, while the bottom of the corridor contains tools 16, 17, 18 air injection.

The tray 11 is essentially in a horizontal plane performed so as to form a specified fluidized bed to collect so granular substances.

Means of air injection can be made in the form of a porous wall 18, such as a grid forming the bottom of the tray at the output of the camera 17 redundantly what about the pressure, equipped with 16 gas supply.

In alternative means of air injection can be made in the form of multiple metal nozzles distributed in the bottom of the specified tray before the chamber is under pressure, equipped with gas supply.

Peripheral corridor specified tray can be made in the form of a set of straight grooves connected by their ends in the form of a polygon.

The device may include means for rashes substances collected in the specified tray, one or more of the collectors 22. For this purpose, these funds may be made in the form of top removal tools, lower removal tools, tools selection, etc.

According to a not shown example, each straight groove of the polygon may have a slight slope, with the corridor sections form aeroginosa. Below each of these chanels possible to provide a collector for collecting granular substances.

According to another variant implementation, shown in figure 2, we are talking about the manifold 22, the inside peripheral corridor. According to this example substances are removed through overflow or pouring.

Thus, the collector or collectors 22 can be positioned inside the peripheral corridor, as shown in figure 2, or on the peripheral corridor, particularly in the corner of the polygon, or outside peripheral corridor.

After collecting the substance in the reservoir 22 can be removed by means of the handling device 23. The handling device 23 may be made in the form of aeroginosa, or mechanical conveyor, such as a screw, chain conveyor, vibrotransporter, belt conveyor and so on

Preferably, the output means 14 10 fee may be on a small vertical distance relative to the rotor position.

The flow of the substances specified in the casing 6 can be produced in the gas flow is in a suspended state. Alternative or additionally, the flow of the substance can be done by gravity on the rotor, or it can dissipate, using a rotating platform 24 fixedly connected in rotation with the rotor. In all cases, the supplied substance behaves in large numbers in the area between the vanes and rotor blades, where they are sorted.

What follows is a description of examples, shown in figure 2 and 3.

The example shown in figure 2, includes a rotor 2 has a cylindrical shape with a vertical axis And equipped on its periphery with blades 3 mounted at equal intervals. Through the rotor 2 passes the gas stream with particles that penetrates through the side surface of the rotor and enters the center of the upper base axially in the direction towards the outlet 9. Another lower base 25 is fully closed.

The rotor 2 is driven by the driving motor through a vertical shaft 26.

When the rotor 2 on the particles acts centrifugal force, which prevents them from passing through the blade 3, while the velocity of the gases creates a captivating force of the stream, which carries the fine particles towards the center. The balance between the two forces leads to the fact that the smaller particles are fond of along with the gas to the outlet 9, while larger particles are rejected by the rotor and falling in the tool 10 of the collection.

According to the invention means 10 collection include peripheral fluidized bed, in which the layer is located around the axis And a cylindrical rotor 2, at least the bottom of the blades 7 and below the intermediate space enclosed between the vanes 7 and the rotor 2 of the device. This layer covers the specified intermediate space between the vanes 7 and the blades 3 of the rotor, and from this intermediate space most not dragged and dropped rotor particles falling down.

The rotor 2 is surrounded by vertical blades 7 arranged at equal intervals in the form of an imaginary cylinder. These blades are equipped with a rotary fingers along the vertical axis, which enable them to be offset to adjust them to the management to adapt the gas velocity, reaching the rotor to the rotational speed of the rotor. Turning fingers all the guide vanes 7 are connected with a single device that allows you to simultaneously focus all blades at the same angle relative to the peripheral surface of the rotor.

The rotor 2 is also equipped with blades 27, located between the peripheral blades 3 and the shaft 26 and the guide to the outlet of the gas streams emerging from the peripheral blades 3, which allows to avoid the formation of eddies within the rotor.

The submission of the matter to the rotor 2 passes through the upper point 81 filing and scatters space 24. Part of powdery substances may also go together with the flow of 51 gas. Sort of substances dispersed or held in suspension in the gas flow occurs mainly in the intermediate space between the blades and rotor.

According to this example shown in figure 2, means to feed gas flow formed by the specified casing 6, and a vertical pipe 5, continuing the specified casing 6 down. Thus, the node cover/vertical pipe covers from the bottom up, these funds 10 collection, as well as the node blades 7/cylindrical rotor 2. According to this example shown in figure 2, the means 10 collection include a tray forming a peripheral corridor formed consequently the capacity of direct chute, United ends. According to this non-limiting example, the eruption of granular substances from the fluidized bed occurs due to overflow. As shown in the figure, the outer Board 21 of the specified tray is located above the inner side 20, with the specified outer Board form Board for rashes substances into the reservoir 22. The collector 22 removes substances by means of the handling device 23, mainly located horizontally, such as aerogels.

The example shown in figure 3 differs from the example in figure 2 by means of the feed gas stream.

According to this example shown in figure 3, the use of feed gas flow formed by the specified casing 6, which surrounds the site of the blades 7/cylindrical rotor 2, with the exception of these funds 10 collection, access to which is free, in particular for maintenance operations. These blades 7 form a side surface of an imaginary cylinder coaxial with the axis of the cylindrical rotor 2. The volume between the inner wall of the specified casing 6 and the side surface of the specified imaginary cylinder, forms a curl.

Other elements of the device shown in figure 3, are identical to the elements of the device in figure 2. A straight section of the curve in each radial plane intersecting the axis of otara, can be reduced, in particular linearly, depending on the angle in the center, the beginning of which is the inlet 61 of the gas supply.

In the case of powder, supplied in suspension in the gas stream, the casing 6 forming the outer wall of the curl can be a double slope with a section of the lower wall 64, tilted, in particular, at an angle relative to horizontal that is greater than or equal to 30°, and with a vertical section of the upper wall 65.

Inclined bottom wall 64 due to its tilt avoids deposition of powdery substances and, consequently, the formation of the layer substances accumulating in the curl.

Preferably, according to a variant implementation, shown in figure 5, the peripheral system fluidized bed allows you to leave the recess 30 within the specified systems for the installation of the drive rotor at the bottom, which makes it simpler than in the case of a top drive.

According to this configuration, the clearance height can be further restricted due to the smaller length of the shaft 26 rotation. According to this example, the different parts forming the peripheral corridor specified tray 11 may have one or more bends, below which or from which you can select one or more of the above-described collectors for collecting substances.

An advantage of the invention I have is the location and operation of collection, in particular, the fluidized bed to reduce the bypass flow.

Thus, preferably, the velocity of the gas fluidized bed in horizontal cross-section may be less than 1 m/s, in particular between 30 and 50 mm/s to minimize the amount of the smaller particles carried along with the cast of large particles.

This average velocity of fluidization ask so that was a new sort (new division), in which only the fine particles smaller than a given particle size, fond of air that enters from the corridor, and into the gas flow entering into the intermediate space between the blades and the blades of the device. Thus, the portion of the smaller particles, which were discarded by the rotor during the first separation process can return to the zone of the sort in front of the rotor.

If, on the contrary, in the process of fluidization large particles larger than a given grain size, are fond of the air stream exiting the corridor, these particles will remain new sorting process and are discarded by the rotor, thus avoiding any reduction in performance. Thus, an object of the present invention is also a method of using centrifugal is the first device 1 granulometric separation in accordance with the present invention, which faction powdery substance serves in the specified casing 6 between the vanes and the rotor device and share it with one hand on the small fraction of substances with a particle size lower than a given particle size, dragged the specified incoming gas flow through the rotor to the output, in particular to the upper output device, and, on the other hand, a large fraction with a particle size exceeding a specified grain size, cast cylindrical rotor and falling in the specified collection tools.

According to the method in accordance with the present invention, the average air velocity of fluidization in horizontal section of the fluidised bed set below 1 m/s to minimize the emissions of the number of particles smaller than this specified particle size.

Of course, it is possible to envisage other ways to exercise without going beyond the scope of the invention defined by the following claims.

1. Centrifugal device (1) selective granulometric separation of solid powdery substances made with the possibility of separation of substances into two fractions - a fraction of small substances and a large fraction of substances containing casing (6), a cylindrical rotor (2) distributed along the periphery of the blades (3), R is sporogony within the specified casing (6) and relatively rotating around a vertical axis, money supply in the casing (6) of the gas flow entering into the rotor (2) through the blades (3), a set of blades 7 mounted stationary within the casing 6 and surrounding the rotor 2, is performed, if necessary, to control its direction and located coaxially with blades (3), so that through them could be specified by the incoming gas stream, means (8) feed intended for sorting solid substances specified in the casing (6) between the blades (7) and the rotor (2), output (9) of the rotor (2) removal of the gas stream and carried along with him fine substances, the means (10) collection below the specified rotor (2), for not dragged by gas falling of large substances, characterized in that the said means (10) collection contain peripheral fluidized bed, the layer which is located around the axis (A) of the rotor (2), at least under the said vanes (7) and the intermediate space, concluded between the said vanes (7) and the rotor (2), the velocity of gas fluidization in horizontal section of the fluidized bed is less than 1 m/s to produce a new division between small matters and large substances, where these small substances back into the intermediate space between these zones and the specified rotor.

2. The device according to claim 1, in which the peripheral is Kai system fluidized bed contains a tray (11), forming a peripheral corridor, while the bottom of the corridor contains means (16, 17, 18) air injection.

3. The device according to claim 2, in which the peripheral corridor formed by a set of straight grooves connected by their ends in the form of a polygon.

4. The device according to claim 2 or 3, in which the means of air injection is made in the form of a porous wall (18), such as a grid forming the bottom of the tray (11) to the outlet chamber (17) excess pressure, equipped with means (16) of the gas supply.

5. The device of claim 2 or 3, wherein in the bottom of the specified tray into the output chamber pressure, equipped with gas supply, made many nozzles.

6. The device of claim 2 or 3, containing remedies for rashes substances collected in the specified tray, one or more collectors (22).

7. The device according to claim 4, containing remedies for rashes substances collected in the specified tray, one or more collectors (22).

8. The device according to claim 5, containing remedies for rashes substances collected in the specified tray, one or more collectors (22).

9. The device according to claim 6, in which material from the specified collector (22) is removed by means of the handling device (23), such as aerogels, screw conveyor, chain conveyor, vibrotransporter, belt conveyor.

YoY according to claim 7 or 8, in which material from the specified collector (22) is removed by means of the handling device (23), such as aerogels, screw conveyor, chain conveyor, vibrotransporter, belt conveyor.

11. Device according to any one of claims 1 to 3, 7 to 9, in which the velocity of the gas fluidization in horizontal section of the fluidized bed is less than 1 m/s, in particular from 30 to 50 mm/s

12. Device according to any one of claims 1 to 3, 7 to 9, in which said cash flow of gas formed by the specified casing (6), and the vertical pipe (5)continuing the specified cover down, the node cover/vertical pipe covers upwards specified means (10) collection, as well as the site of the blades (7)/cylindrical rotor (2).

13. Device according to any one of claims 1 to 3, 7 to 9, in which said cash flow of gas formed by the casing (6)which surrounds the site of the blades (7)/cylindrical rotor (2), except for the means (10) collection, while the gas supply is located on the side, and the blade (7) form a side surface of an imaginary cylinder coaxial with the axis (A) of the cylindrical rotor (2)and the volume limited by the inner wall of the specified casing (6) and the side surface of the specified imaginary cylinder, forms a curl.

14. The device according to item 13, wherein said casing (6), which forms the outer wall of the volute, which meet the dual slope with section bottom wall (64), inclined at an angle relative to horizontal that is greater than or equal to 30°, and with a vertical section of the upper wall (65).

15. The device according to item 13, in which the means driving the rotor from the bottom to the specified rotor.

16. The device 14 in which the means driving the rotor from the bottom to the specified rotor.

17. Device according to any one of claims 1 to 3, 7 to 9, 14 to 16, in which the output of (9) is above the rotor (2) and located with respect to these funds flow of gas from the formation of the upward gas flow within the specified rotor (2).

18. The method of using centrifugal device (1) granulometric separation according to one of claims 1 to 17, in which the fraction of powdery substances are served in the specified casing (6) between the vanes and the rotor device and divide it into small fraction of the substance with a particle size lower than a given particle size, dragged the specified incoming gas flow through the rotor to the output (9), namely to the upper output device (1), and a large fraction with a particle size exceeding a specified grain size, cast cylindrical rotor and means for collecting the specified device, according to the middle way the velocity of fluidization in horizontal section of the fluidised bed set below 1 m/s to minimize the number of rejected particles, smaller than this specified particle size.