CN211275001U

CN211275001U - Medium speed coal mill coarse powder separator adopting axial separation device

Info

Publication number: CN211275001U
Application number: CN201922101413.XU
Authority: CN
Inventors: 时勇强; 晋中华; 员盼锋; 王岩; 杨培军
Original assignee: Thermal Power Research Institute
Current assignee: Xian Thermal Power Research Institute Co Ltd
Priority date: 2019-11-28
Filing date: 2019-11-28
Publication date: 2020-08-18
Anticipated expiration: 2029-11-28

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

Medium speed coal mill coarse powder separator adopting axial separation device

Technical Field

The utility model relates to a medium speed pulverizer middlings separator, concretely relates to medium speed pulverizer middlings separator who adopts axial separation device.

Background

The coarse powder separator is a key device of a medium speed coal mill and is used for separating coal powder ground by the medium speed coal mill according to the particle size, namely fine powder (qualified coal powder) with the particle size smaller than a certain particle size is directly fed into a hearth as a product along with a medium to be combusted. Coarse particles (unqualified coal powder) with the particle size larger than the particle size are separated from the airflow and returned to the coal mill for grinding again.

The ratio of the inlet to outlet coal dust amounts of the coarse powder separator is called the circulation rate, and the circulation rate is an index reflecting the amount of the recycled coal dust between the coarse powder separator and the coal mill. The coarse powder separator with ideal performance can bring out most qualified fine coal powder along with airflow, most of the coal powder returned to the coal mill for re-grinding is unqualified coarse particles, the circulation rate is low, the resistance of the coal mill is correspondingly low, the output of the coal mill is good, the ventilation power consumption and the coal grinding power consumption of the coal mill are low, and electricity and energy are saved.

The coarse powder separator adopted by the prior medium-speed coal mill is mainly a radial coarse powder separator. The radial coarse powder separator has the problems of high circulation rate, large resistance and poor separation effect in practical application, the resistance of the coal mill is increased, the output of the coal mill is influenced, and the power consumption of the coal mill is increased.

The axial separation technology is a replacement product of a radial coarse powder separator and is generally applied to a powder-making system of a steel ball coal mill. Practical application results show that the coarse powder separator adopting the technology is low in circulation rate and high in separation efficiency. However, due to the special structure of the medium speed coal mill, the axial separation technology is not applied to the medium speed coal mill at present.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome above-mentioned prior art's shortcoming, provide an adopt axial separation device's medium speed pulverizer middlings separator, this separator can the radial type middlings separator high problem of circulation multiplying power of effectual solution medium speed pulverizer.

In order to achieve the above object, the middle speed coal mill coarse powder separator adopting the axial separation device comprises a separator shell, and a grinding roller, a grinding disc, an air ring, a coal dropping pipe, a powder returning inner cone and the axial separation device which are arranged in the separator shell, wherein the grinding disc and the air ring are positioned at the bottom of the separator shell, the air ring is distributed at the periphery of the grinding disc, the grinding roller is positioned on the grinding disc, the powder returning inner cone is of a hollow structure, the powder returning inner cone and the axial separation device are both positioned above the grinding disc, the axial separation device is positioned between the powder returning inner cone and the inner wall of the separator shell, the upper end of the coal dropping pipe is positioned outside the separator shell, the lower end of the coal dropping pipe penetrates through the powder returning inner cone after being inserted into the separator shell from the top of the separator shell, and the lower end of the coal dropping pipe is positioned right above the grinding;

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

The air inlet pipeline is provided with an air door.

The powder outlet pipes are distributed along the circumferential direction.

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

The utility model discloses following beneficial effect has:

the utility model discloses an adopt axial separator's medium speed coal pulverizer middlings separator when concrete operation, raw coal grinds into the fine coal powder through the grinding roller, and upward movement under hot-blast drive, wherein, relatively thick unqualified buggy drops to mill again on the mill under the effect of gravity, accomplish coarse separator's gravity separation, buggy air current separates through axial separator, another part thick unqualified buggy that separates gets back to mill again through striking separation, accomplish coarse separator's striking separation, axial separator can make the buggy air current that passes through produce the rotation simultaneously, rotatory buggy air current can throw away some thick buggy and fall back to in the powder cone in the unqualified buggy, and finally drop the mill and mill again, thereby effectively reduce circulation multiplying power, reduce system resistance, improve the coal pulverizer and exert oneself, reduce the power consumption rate of the powder process.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

Wherein, 1 is an air door, 2 is a grinding disc, 3 is an air ring, 4 is a grinding roller, 5 is an axial separation device, 6 is a powder outlet pipe, 7 is a powder return inner cone, and 8 is a coal dropping pipe.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings:

referring to fig. 1, the medium speed coal mill coarse powder separator using the axial separation device of the present invention comprises a separator housing, and a grinding roller 4, a grinding disc 2, an air ring 3, a coal dropping pipe 8, a return powder inner cone 7 and an axial separation device 5 which are arranged in the separator housing, the grinding disc 2 and the air ring 3 are positioned at the bottom of the separator shell, the air ring 3 is distributed on the periphery of the grinding disc 2, the grinding roller 4 is positioned on the grinding disc 2, the powder return inner cone 7 is of a hollow structure, the powder return inner cone 7 and the axial separating device 5 are both positioned above the grinding disc 2, the axial separating device 5 is positioned between the powder return inner cone 7 and the inner wall of the separator shell, the upper end of a coal dropping pipe 8 is positioned outside the separator shell, the lower end of the coal dropping pipe 8 penetrates through the powder return inner cone 7 after being inserted into the separator shell from the top of the separator shell, and 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.

Wherein, the air inlet pipeline is provided with an air door 1; all the powder outlet pipes 6 are distributed along the circumferential direction; the powder returning inner cone 7 is of an inverted frustum-shaped hollow structure.

The utility model discloses a concrete operation process does:

hot air enters the lower part of the coal mill through an air door 1, is blown into the coal mill from an air ring 3 upwards, raw coal falls onto a grinding disc 2 through a coal dropping pipe 8 and is ground into fine coal powder through a grinding roller 4, the ground fine coal powder is thrown onto the air ring 3 through the rotation of the grinding disc 2 and is driven by hot air blown out by the air ring 3 to move towards the upper part of the coal mill, and in the process of upward movement of coal powder airflow, because the through flow area is gradually increased, the ascending speed of the airflow is gradually reduced, and a part of unqualified coal powder which is relatively thick falls back onto the grinding disc 2 to be ground again, so that the gravity separation of a coarse powder separator is completed; the coal dust airflow continuously rises and passes through the axial separation device 5, and the other part of unqualified coarse coal dust is separated by impact and returned to the grinding disc 2 for grinding again, so that the impact separation of the coarse powder separator is completed. The axial separation device 5 can simultaneously rotate the passing pulverized coal airflow, the rotating pulverized coal airflow can throw out a part of unqualified coarse pulverized coal and fall into the powder return inner cone 7, finally the unqualified coarse pulverized coal falls onto the grinding disc 2 through the powder return inner cone 7 to be ground again, the rotary separation of the coarse powder separator is completed, and the separated pulverized coal airflow leaves the coal mill through the powder outlet pipe 6.

Claims

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.