CN211275001U - A medium-speed coal mill coarse powder separator using an axial separation device - Google Patents

Abstract

The utility model discloses an adopt axial separation device's medium speed pulverizer middlings separator, mill and wind ring are located the bottom of separator casing, and the wind ring distributes in the periphery of mill, the grinding roller is located the mill, return the powder interior and be hollow structure, return powder interior and axial separation device all are located the top of mill, axial separation device is located between the inner wall of returning powder interior and separator casing, the upper end of coal breakage pipe is located outside the separator casing, the lower extreme of coal breakage pipe passes back the powder interior after inserting in the separator casing from the top of separator casing, and the lower extreme of coal breakage pipe is located directly over the mill; the air inlet pipeline is communicated with the air ring, the top of the separator shell is communicated with a plurality of powder outlet pipes, and the separator can effectively solve the problem that the radial coarse powder separator of the medium-speed coal mill is high in circulation rate.

Description

A medium-speed coal mill coarse powder separator using an axial separation device

technical field

The utility model relates to a medium-speed coal mill coarse powder separator, in particular to a medium-speed coal mill coarse powder separator using an axial separation device.

Background technique

The coarse powder separator is the key equipment of the medium speed coal mill. pulverized coal), as a product, it is directly sent to the furnace for combustion with the medium. The coarse particles (unqualified pulverized coal) with a particle size larger than this particle size are separated from the airflow and returned to the coal mill for re-grinding.

The ratio of the amount of pulverized coal at the inlet to the outlet of the coarse powder separator is called the cycle ratio, and the cycle ratio is an index reflecting the amount of recycled pulverized coal between the coarse powder separator and the coal mill. The coarse powder separator with ideal performance can take most of the qualified fine coal powder out with the airflow, and most of the coal powder returned to the coal mill for re-grinding is unqualified coarse particles, the circulation rate is low, and the coal is ground. The resistance of the coal mill is correspondingly lower, the output of the coal mill is better, the ventilation power consumption of the coal mill and the coal grinding power consumption are both lower, saving electricity and energy.

At present, the coarse powder separator used in medium-speed coal mills is mainly radial coarse powder separator. In practical application, the radial coarse powder separator has the problems of high cycle rate, large resistance and poor separation effect, which increases the resistance of the coal mill, affects the output of the coal mill, and increases the power consumption of the coal mill.

The axial separation technology is the replacement product of the radial coarse powder separator, and has been widely used in the pulverization system of the steel ball mill. The practical application results show that the coarse powder separator using this technology has low circulation rate and high separation efficiency. However, due to the special structure of the medium-speed coal mill, the axial separation technology has not yet been applied to the medium-speed coal mill.

Utility model content

The purpose of this utility model is to overcome the shortcomings of the above-mentioned prior art, and to provide a medium-speed coal mill coarse powder separator adopting an axial separation device, which can effectively solve the The problem of high circulation rate of powder separator.

In order to achieve the above purpose, the medium-speed coal pulverizer coarse powder separator using an axial separation device according to the present utility model includes a separator shell and grinding rollers, grinding discs, air rings, and coal falling pipes arranged in the separator shell. , Inner cone for returning powder and axial separation device, wherein the grinding disc and air ring are located at the bottom of the separator shell, and the air ring is distributed on the outer circumference of the grinding disc, the grinding roller is located on the grinding disc, the inner cone for returning powder is a hollow structure, and the powder returning The inner cone and the axial separation device are both located above the grinding disc, the axial separation device is located between the inner cone of the powder return and the inner wall of the separator shell, the upper end of the coal drop pipe is located outside the separator shell, and the lower end of the coal drop tube separates itself The top of the separator shell is inserted into the separator shell and passes through the powder return inner cone, and the lower end of the coal falling pipe is located directly above the grinding disc;

The air inlet pipe is communicated with the air ring, and the top of the separator shell is communicated with a number of powder outlet pipes.

The air inlet duct is provided with a damper.

Each powder outlet pipe is distributed along the circumferential direction.

The powder-returning inner cone is an inverted cone-shaped hollow structure.

The utility model has the following beneficial effects:

During the specific operation of the medium-speed coal mill coarse powder separator using the axial separation device according to the utility model, the raw coal is ground into fine coal powder by the grinding rollers, and moves upwards under the drive of hot air. The coarse unqualified pulverized coal falls to the grinding table under the action of gravity for re-grinding, and the gravity separation of the coarse powder separator is completed. The pulverized coal is separated by impact and returned to the grinding plate for re-grinding, completing the impact separation of the coarse powder separator. The qualified pulverized coal is thrown out and falls into the inner cone of the powder return, and finally falls to the grinding table for re-grinding, thereby effectively reducing the cycle rate, reducing the resistance of the system, increasing the output of the pulverizer, and reducing the power consumption rate of pulverizing.

Description of drawings

Figure 1 is a schematic structural diagram of the utility model.

Among them, 1 is the air door, 2 is the grinding disc, 3 is the air ring, 4 is the grinding roller, 5 is the axial separation device, 6 is the powder outlet pipe, 7 is the inner cone of the powder returning, and 8 is the coal falling pipe.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is described in further detail:

Referring to FIG. 1 , the medium-speed coal mill coarse powder separator using an axial separation device according to the present utility model includes a separator shell and a grinding roller 4, a grinding disc 2, an air ring 3, a falling The coal pipe 8, the inner cone 7 for returning powder and the axial separation device 5, wherein the grinding disc 2 and the air ring 3 are located at the bottom of the separator shell, and the air ring 3 is distributed on the outer circumference of the grinding disc 2, and the grinding roller 4 is located on the grinding disc 2 , the powder-returning inner cone 7 is a hollow structure, the powder-returning inner cone 7 and the axial separation device 5 are both located above the grinding disc 2, and the axial separation device 5 is located between the powder-returning inner cone 7 and the inner wall of the separator shell. The upper end of the coal pipe 8 is located outside the separator shell, the lower end of the coal drop pipe 8 is inserted into the separator shell from the top of the separator shell and then passes through the powder return inner cone 7, and the lower end of the coal drop pipe 8 is located at the bottom of the grinding disc 2. Right above; the air inlet duct is communicated with the air ring 3, and the top of the separator shell is communicated with a number of powder outlet pipes 6.

Among them, the air inlet duct is provided with a damper 1; each powder outlet pipe 6 is distributed along the circumferential direction; the powder return inner cone 7 is an inverted cone-shaped hollow structure.

The concrete operation process of the present utility model is:

The hot air enters the lower part of the coal mill through the damper 1, and blows upward from the air ring 3 into the coal mill. , so that the fine pulverized coal after grinding is thrown onto the air ring 3, and is driven to the upper part of the coal mill by the hot air blown out by the air ring 3. The rising speed of the air flow gradually decreases, and a part of the relatively coarse unqualified pulverized coal will fall back to the grinding plate 2 for re-grinding to complete the gravity separation of the coarse powder separator; The coarser unqualified coal powder is separated by impact and returned to the grinding disc 2 for re-grinding to complete the impact separation of the coarse powder separator. At the same time, the axial separation device 5 will make the passing pulverized coal gas flow to rotate, and the rotating pulverized coal gas flow will throw out a part of the coarse unqualified pulverized coal and fall into the inner powder return cone 7, and finally pass through the powder return inner cone 7. It falls on the grinding disc 2 for re-grinding to complete the rotary separation of the coarse powder separator, and the separated coal powder flow leaves the coal mill through the powder outlet pipe 6.

Claims (4)

1. A medium speed coal mill coarse powder separator adopting an axial separation device is characterized by comprising a separator shell, a grinding roller (4), a grinding disc (2), an air ring (3), a coal dropping pipe (8), a powder return inner cone (7) and the axial separation device (5), wherein the grinding roller (4), the grinding disc (2), the air ring (3), the grinding roller (4), the coal dropping pipe (8), the powder return inner cone (7) and the axial separation device (5) are arranged in the separator shell, the grinding roller (3) is distributed on the periphery of the grinding disc (2), the powder return inner cone (7) is of a hollow structure, the powder return inner cone (7) and the axial separation device (5) are both positioned above the grinding disc (2), the axial separation device (5) is positioned between the powder return inner cone (7) and the inner wall of the separator shell, the upper end of the coal dropping pipe (8) is positioned outside the separator shell, the top of the coal dropping pipe (8) penetrates through the powder return inner cone (7) after being inserted into the separator shell, the lower end of the coal dropping pipe (8) is positioned right above the grinding disc (2);

the air inlet pipeline is communicated with the air ring (3), and the top of the separator shell is communicated with a plurality of powder outlet pipes (6).

2. The medium speed coal mill coarse powder separator adopting an axial separation device according to claim 1, wherein a damper (1) is arranged on the air inlet pipeline.

3. The medium speed coal mill coarse powder separator using an axial separation device according to claim 1, wherein each powder outlet pipe (6) is circumferentially distributed.

4. The medium speed coal mill coarse powder separator adopting the axial separation device as claimed in claim 1, wherein the return powder cone (7) is of an inverted truncated cone-shaped hollow structure.

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