JPS5850782B2 - Powder classification method and device - Google Patents

Description

[Detailed description of the invention] The present invention relates to a powder classification method and apparatus.

By sending the raw material to be crushed and hot air or cold air to the crusher to dry or cool the raw material to be crushed, the performance of the crusher can be improved or the functions of the crusher can be expanded, and The extracted powder is supplied to a powder classification device attached to the pulverizer and classified into fine powder and coarse powder.The fine powder is taken out of the system as a product, while the coarse powder is returned to the pulverizer and over-pulverized. It is known in the art to improve the grinding capacity of a grinder by preventing this.

In this case, it is not a good idea to rely entirely on fluids such as the hot air mentioned above to transport the powder from the crusher to the powder classification device, as it is not a good idea in terms of energy consumption. A combination of processes are used: removing the body from a crusher, scraping it out, and transporting it using a conveyor such as a packet elevator.

Next, the conventional closed circuit pulverization and classification system will be explained with reference to Fig. 1.A is a fluid supply pipe such as hot air, b is a feeder for supplying the raw material to be pulverized, C is a pulverizer (tube mill), and d is a powder discharge pipe. , e is a conveyor such as a packet elevator, f is a powder supply pipe, g is a powder classification device that classifies powder using a dispersion plate, separation blades, and swirling upward flow, h is a fine powder discharge pipe, and i is a coarse powder A discharge pipe, j is a powder classification device in which a fluid supply pipe k branched from the middle of the powder discharge pipe d classifies powder by swirling upward flow, l is a fluid discharge pipe, m is a coarse powder discharge pipe, and n is a A cyclone type dust collector, 0 is a fine powder discharge pipe, p is a fluid discharge pipe, and q is a fan, which sends hot air from the supply pipe a to the crusher C, and sends the raw material to be crushed from the feeder b to the crusher C, respectively. Dry and grind.

Among the powders discharged from the crusher C, powders that cannot be transported by fluid are sent to the powder classifier g via the discharge pipe d → conveyor e → supply pipe f, while those that cannot be transported by fluid The powder together with the fluid is sent to a powder classifier k via a supply pipe j.

In the upper part of the powder classification device g, a dispersion plate, a separation blade, and a fan are provided coaxially, and an inverted conical annular flow path is provided from the classification area around these downwards along the outer wall. The lower end thereof communicates with the fine powder discharge pipe, and the inside of the classifier g inside the annular flow path communicates with the coarse powder discharge pipe i, respectively.
The powder supplied from the supply pipe f into the classifier g is
It is directed toward the outer wall by the centrifugal force exerted by the rotating dispersion plate, but there is a swirling upward flow generated by the fan inside the classifier g, which rises and is struck by the rotating separating blades, creating an even stronger centrifugal force. Take it and head towards the outside wall.

At this time, due to the difference between the drag force exerted on the powder by the swirling upward flow and the centrifugal force exerted on the powder in the direction of the outer wall of the separation vane, the powder is classified into fine powder and coarse powder, and the fine powder moves downward in the annular flow path together with the fluid. On the other hand, it is taken out as a product from the exhaust pipe,
The coarse powder descends in the classifier g inside the annular flow path and is returned to the feeder b through the discharge pipe i.

Further, inside the powder classification device, an inverted conical annular flow path is provided upward along the outer wall, and at the upper end of the annular flow path,
A fluid supply section is provided that supplies fluid into the classifier as an upward swirling flow, and the fluid containing powder supplied from the supply pipe j to the classifier k rises within the annular flow path.
The fluid is supplied from the fluid supply section to the classifier as a swirling upward flow.

At this time, the powder in the fluid is classified into fine powder and coarse powder due to the difference between the drag force exerted on the powder by the swirling upward flow and the centrifugal force in the direction of the outer wall, and the fluid containing fine powder passes through the discharge pipe l. It is sent to a cyclone dust collector and separated into fine powder and fluid.
Fine powder is taken out of the system as a product through discharge 0, and fluid is sucked in the direction of discharge pipe p by fan q.

Further, the coarse powder in the classification device is returned to the feeder b through the discharge pipe m.

In the closed-circuit crushing and classification system, a fan is required for each of the two powder classifiers, and as a result, a large-capacity cyclone dust collector or electrostatic precipitator is required. powder classifier g,
k must be installed in parallel, requiring a large installation space and increasing equipment costs.

Furthermore, as mentioned above, a fan is required for each of the two powder classifier systems, making operation and maintenance troublesome.

The present invention eliminates the above-mentioned defects by transporting a part of the powder pulverized in a pulverizer using a fluid such as hot air, and transporting the remaining powder by a transporter such as a packet elevator, thereby creating a powder classification apparatus. The powder is then classified into fine powder and coarse powder in the same classification device.
In a powder crushing and classification system in which the coarse powder is returned to the crusher, the powder conveyed by the conveyor is supplied to the first classification chamber of the powder classifier, where it is diffused and separated by a rotating dispersion plate and separating blades, and heated by hot air, etc. From the fluid inlet at the lower end of the second classification chamber located below the first classification chamber, the powder conveyed by the annular passage formed inside the outer wall of the second classification chamber and the fluid provided above the annular passage. The fluid is supplied to the second classification chamber through the outlet and a movable guide vane arranged inside the fluid outlet to generate a swirling upward flow to separate the airflow, and the coarse powder separated in the first classification chamber is separated into the second classification chamber. The coarse powder separated in the second classification chamber is discharged to the outside of the second classification chamber from the coarse powder outlet provided at the bottom of the second classification chamber, and the swirling upward flow is passed through the second classification chamber. The separated fine powder is led to the first classification chamber to be used as a separation fluid for the first classification chamber, and then the fine powder separated in the first classification chamber is passed through the fine powder discharge port provided at the upper part of the side wall of the first classification chamber to the first classification chamber. The present invention relates to a powder classification method characterized by discharge outside the room, and its intended purpose is to significantly reduce equipment costs.

Another object of the present invention is to provide an improved powder classification method that facilitates operation and maintenance.

The present invention transports a part of the powder pulverized in the pulverizer as described above with a fluid such as hot air, transports the remaining powder with a transport machine such as a packet elevator, and supplies it to a powder classification device. In the powder crushing and classification system, the powder is classified into fine powder and coarse powder in the same classification device, and the coarse powder is returned to the above-mentioned crusher. The fluid is supplied from the fluid inlet to the second classification chamber through an annular passage formed inside the outer wall of the second class chamber, a fluid outlet provided at the top of the annular passage, and a movable guide vane arranged inside the fluid outlet. The powder is diffused and separated by a rotating dispersion plate and separation blades, and transported by hot air, etc., and then supplied to a second classification chamber located below the first classification chamber to generate a swirling upward flow. The coarse powder separated in the first classification chamber is led to the second classification chamber, and the coarse powder separated in the second classification chamber is passed through the second classification chamber.
The coarse powder discharge port provided at the bottom of the classification chamber is discharged to the outside of the second classification chamber, and the swirling upward flow is guided to the first classification chamber together with the fine powder separated in the second classification chamber, and the separation fluid in the first classification chamber is After that, the fine powder separated in the first classification chamber is discharged to the outside of the first classification chamber from the fine powder discharge port provided at the upper part of the side wall of the first classification chamber, so the swirling upward flow generated in the second classification chamber is It can also be used in a classification room, just by installing one fan in the powder classification system.

Also, because of this, a small-capacity cyclone dust collector or electrostatic dust collector can be used.

Furthermore, the space below the first classification chamber can be used as the installation space for the second classification chamber, reducing the installation space.

Therefore, equipment costs can be significantly reduced. Furthermore, in the powder classification method of the present invention, the swirling upward flow generated in the second classification chamber can also be used in the first classification chamber as described above, and only one fan needs to be installed in the powder classification system. It has the effect of facilitating maintenance, and is very useful when applied to cement raw material crushing and classifying systems, ore-containing crushing and classifying systems, etc.

Further, in the present invention, a part of the powder crushed in the crusher is conveyed by a fluid such as hot air, and the remaining powder is conveyed by a conveyor such as a packet elevator, and then supplied to a powder classification device. In the powder crushing and classification system, the powder is classified into fine powder and coarse powder, and the coarse powder is returned to the crusher. A first classification chamber is provided with a dispersion plate and separation blades provided below the outlet, a fine powder discharge port provided at the top of the side wall, and a fluid supply section provided above that supplies the powder transported by hot air or the like as an upward swirling flow. , a coarse powder discharge port is provided at the bottom, and a second classification chamber is provided at the bottom, and the second classification chamber is arranged at a distance inside the outer wall of the second classification chamber, and between the second classification chamber and the outer wall. An inner casing forming an annular passage, a fluid inlet provided at the lower end of the annular passage, a plurality of fluid outlets provided circumferentially along the upper part of the inner casing, and opposing fluid outlets inside each fluid outlet. It consists of a plurality of movable guide vanes provided so as to
A powder classification apparatus characterized in that the second classification chamber is disposed below the first classification chamber and the interiors of the respective classification chambers are communicated with each other, and the powder classification method can be carried out smoothly. It is.

Next, the powder classification method and apparatus of the present invention will be explained with reference to an embodiment shown in FIGS. 2 to 5.
is a fluid supply pipe such as hot air, 2 is a feeder for supplying the raw material to be crushed, 3 is a preliminary crusher, 4 is a powder supply pipe, 5 is a fluid discharge pipe,
6 is a crusher (tube mill), 7 is a powder discharge pipe, 8 is a conveyor such as a packet elevator, 9 is a powder supply pipe, 10 is a powder classification device that is the most distinctive feature of the present invention, and 11 is a fluid discharge 12 is a coarse powder discharge pipe, 13 is a fine powder discharge pipe, 14 is an electrostatic precipitator, 15 is a fine powder discharge pipe, and 16a.

16b, 16c, and 16d are fluid discharge pipes, and 17 is a fan.

Next, the powder classification apparatus 10 will be explained in detail with reference to FIG. 10a
19 is the outer wall of the second classification chamber 10b, 21 is an inlet chamber provided below the top 18a of the outer wall 18, and the inlet chamber 21 is connected to the inlet 20 communicating with the powder supply pipe 9, facing downward. It has an open outlet 22.

Further, 23 is a motor with a reducer 24 mounted on the top 18a of the outer wall 18, 25 is a drive shaft driven by the motor 23, 16 is a dispersion plate fixed to the lower end of the drive shaft, 2T
28 is a separating blade fixed on the distribution plate 26, 28 is a guide blade disposed around the inlet chamber 210, and 29 is a separating blade fixed on the above-mentioned outer wall 18.
It communicates with the fine powder discharge pipe 13 through a fine powder discharge port provided at the upper part of the fine powder discharge pipe 13 .

Further, numeral 30 denotes a fluid inlet provided at the bottom of the outer wall 19 of the second classification chamber 10b, which communicates with the fluid discharge pipe 11.

Reference numeral 31 denotes an inverted conical inner casing mounted within the outer wall 19, and an inverted conical annular flow path 32 is formed between the inner casing 31 and the outer wall 19.

Further, there are a plurality of fluid outlets at the upper end of the inner casing 31, each of which opens into the inner casing 31.

Reference numeral 33 designates a plurality of movable guide vanes arranged annularly inside the fluid outlet, and the upper end of a rotating shaft protruding outside the top 19a of the outer wall 19 is connected by an operating link 34.

Further, 35 is a fluid supply port provided at the upper part of the outer wall 19,
It communicates with the fluid discharge pipe 16c.

Further, 36 is the inner casing 31 wall and the outer wall 19.
A coarse powder discharge port whose lower end protrudes outside the outer wall 19 and communicates with the coarse powder discharge pipe 12 .

In FIG. 3, the movement of the fluid containing fine powder is shown by dotted line arrows, and the movement of coarse powder is shown by solid line arrows.

Next, the operation of the powder crushing and classification system will be explained.

Hot air is sent from the supply pipe 1a to the preliminary crusher 3, and raw material to be crushed is sent from the feeder 2 to the preliminary crusher 3, and the raw materials are dried and crushed.

Among the powder discharged from the preliminary crusher 3, powder that cannot be transported by fluid is sent to the crusher 6 via the powder supply pipe 4, while powder that can be transported by fluid is discharged together with the fluid. The fluid is sent via pipe 5 to fluid discharge pipe 11 .

At this time, the hot air from the supply pipe 1a→1b is transferred to the fan 1.
1 → After dilution and temperature reduction with the fluid from the discharge pipe 16b,
The powder is sent to a pulverizer 6 and the coarse powder in the pulverizer 6 is dried and pulverized.

Also, among the powder discharged from the crusher 6, powder that cannot be transported by fluid is sent to the inlet 20 of the first classification chamber 10a via the discharge pipe 7 → conveyor 8 → supply pipe 9; The powder that can be transported to the second classification chamber 10 along with the fluid through the supply pipe 11
It is sent to the entrance 30 of b.

At this time, the fluid containing fine powder from the fluid supply pipe 5 and the fan 1
7→The fluid from the fluid discharge pipe 16d is transferred to the second classification chamber 1.
It joins the fluid heading toward 0b.

Next, the operation of the first and second classification chambers 10a and 10b will be explained.

First, to explain the function of the second classification chamber 10b, the fluid containing powder supplied to the inlet 30 rises in the annular flow path 32 and joins with the fluid from the fan 17→fluid discharge pipe 16c. Movable guide vane 33 from the upper end outlet of the annular flow path 32
It is supplied into the internal casing 31 as a swirling upward flow.

At this time, the powder in the fluid is classified into fine powder and coarse powder due to the difference between the drag force exerted on the powder by the swirling upward flow and the centrifugal force in the direction of the outer wall 19. The coarse powder is supplied to the first classification chamber 10a, and the coarse powder is discharged from the coarse powder outlet 36→
The coarse powder is returned to the crusher 6 via the coarse powder discharge pipe 12.

Next, to explain the operation of the first classification chamber 10a, the fluid containing powder supplied to the inlet 20 is supplied onto the rotating dispersion plate 26 via the inlet chamber 21 → the outlet 22, and the powder in the fluid is is directed toward the outer wall 18 due to centrifugal force, but the dispersion plate 26
There is a swirling upward flow from the second classification chamber 10b around the second classification chamber 10b, which rises and is struck by the rotating separation vane 27, and is directed toward the outer wall 18 under stronger centrifugal force.

At this time, the drag force exerted on the powder by the swirling upward flow and the separation blade 27
Due to the difference between the centrifugal force exerted on the powder in the direction of the outer wall 18,
The fine powder is classified into fine powder and coarse powder, and the fine powder is sent to the electrostatic precipitator 14 along with the fluid between the guide vanes 28 → the fine powder discharge port 29 → the fine powder discharge pipe 13, where it is separated into the fine powder and the fluid, and the fine powder is discharged. The pipe 15 is also taken out as a product outside the system, and the fluid is sucked by the fan 17 in the direction of the discharge pipe 16a.

On the other hand, the coarse powder classified in the first classification chamber 10a falls along the inner surface of the outer wall 18 and joins the coarse powder in the second classification chamber 10b.

In this embodiment, the preliminary crusher 3 is introduced into the powder crushing and classification system, but by doing so, the drying air sweep, which conventionally relied completely on the crusher 6, can be replaced by the preliminary crusher 6.
The fan wind pressure can be reduced due to its low pressure loss.

The present invention has been described above with reference to embodiments, but of course the present invention is not limited to such embodiments, and modifications of God's design may be made without departing from the spirit of the present invention. .

For example, as shown in FIG. 6, fluid such as hot air is supplied from the supply pipe 1 to the crusher 6, and raw material to be crushed is supplied from the feeder 2 to the crusher 6.
Alternatively, as shown in FIG.
9 and the fine powder non-emission pipe 13, a cyclone type dust collector 37 is installed.
may be provided to separate the fine powder from the fluid.

[Brief explanation of the drawing]

FIG. 1 is a system diagram showing a conventional powder crushing and classification system, FIG. 2 is a system diagram showing an embodiment of the powder crushing and classifying system according to the present invention, and FIG. 3 is a system diagram showing a powder classification apparatus according to the present invention. FIG. 4 is a vertical cross-sectional side view showing one embodiment of the invention, and FIG.
A cross-sectional plan view along the line, No. 5, the left half is in the direction of arrow V1 in Fig. 3.
- A cross-sectional plan view taken along the line V1, the right hand part of FIG. Systematic diagram shown, No. 7
The figure is a longitudinal sectional side view showing another embodiment of the powder classification device according to the present invention. 6...Crusher, 8...Transporter, 10.
...Powder classification device, 10a...First classification chamber, 10b...Second classification chamber, 18...
Outer wall of the first classification chamber 10a, 19...Outer wall of the second classification chamber 10b, 20...Entrance, 20...
・Inlet chamber, 22...-Outlet, 26...Dispersion plate, 27...Separation blade, 29-...Fine powder discharge port, 30...・Fluid inlet, 32...
・Annular passage, 33...--Movable guide vane, 36...
...--Coarse powder outlet.

Claims (1)

[Claims] 1. A part of the powder pulverized in a pulverizer is conveyed by a fluid such as hot air, and the remaining powder is conveyed by a conveyor such as a packet elevator and supplied to a powder classification device, In the powder crushing and classification system, the powder is classified into fine powder and coarse powder in the same classification device, and the coarse powder is returned to the crusher.The powder transported by the conveyor is supplied to the first classification chamber of the powder classification device. The powder is diffused and separated by rotating dispersion plates and separation blades, and transported by hot air, etc., from the fluid inlet at the lower end of the second classification chamber located below the first classification chamber to the inside of the outer wall of the second classification chamber. The airflow is supplied to the second classification chamber through an annular passage formed in the annular passageway, a fluid outlet provided at the upper part of the annular passageway, and a movable guide vane arranged inside the fluid outlet to generate a swirling upward flow. separate,
The coarse powder separated in the first classification chamber is led to the second classification chamber, and together with the coarse powder separated in the second classification chamber, it is discharged from the coarse powder outlet provided at the bottom of the second classification chamber to the outside of the second classification chamber. , the swirling upward flow is led to the first classification chamber together with the fine powder separated in the second classification chamber to become a separation fluid for the first classification chamber, and then is transferred to the first classification chamber together with the fine powder separated in the first classification chamber. A powder classification method characterized in that the powder is discharged to the outside of the first classification chamber from a fine powder discharge port provided at the upper part of the side wall. 2 A part of the powder crushed in the crusher is conveyed by fluid such as hot air, and the remaining powder is conveyed by a conveyor such as a packet elevator and supplied to a powder classification device. In a powder crushing and classification system, the coarse powder is classified into coarse powder and coarse powder, and the coarse powder is returned to the crusher. A first classification chamber is provided with a separating blade located below the outlet, a fine powder discharge port provided at the top of the side wall, and a fluid supply section located above that supplies the powder transported by hot air as an upward swirling flow. It consists of a second classification chamber with a discharge port at the bottom, and the second classification chamber is arranged at a distance inside the outer wall of the second classification chamber, and an annular passage is provided between it and the outer wall. A fluid inlet provided at the lower end of the annular passage formed by the inner casing, a plurality of fluid outlets provided along the circumferential direction at the upper part of the inner casing, and a plurality of fluid outlets provided inside each of the fluid outlets so as to face each other. 1. A powder classification device comprising a plurality of movable guide vanes, the second classification chamber being disposed below the first classification chamber, and the insides of the respective classification chambers communicating with each other.