CN103029989B - Novel pebble coal feeding device with separation function - Google Patents

Abstract

The present invention relates to a material conveying component used in the pebble coal pneumatic conveying system of a thermal power plant, especially a novel pebble coal feeding device with separation function, including a material collecting device (1), a feed pipe (2), Intake pipeline (3), valve (4), separation pipeline (5), material delivery pipeline (9), material collection device (1) connected to the front end of the intake pipeline (3) through the feed pipe (2) In the upper part, the rear end of the air intake pipeline (3) is connected to the material delivery pipeline (9), and the connecting position of the air intake pipeline (3) and the material delivery pipeline (9) is provided with a downward separation pipeline (5); The separation method is naturally completed by gravity, and the effect is stable, and since there are two unloading plates in the separation pipeline 5, the unloading plates are opened in turn during unloading, which can avoid the airflow pouring in from the bottom of the separation pipeline 5 during unloading Influence on system stability while completing unloading.

Description

A new type of pebble coal feeding device with separation function

technical field

The invention relates to a material conveying component used in a pebble coal pneumatic conveying system in a thermal power plant, in particular to a pebble coal feeding device.

Background technique

During the operation of coal mills widely used in thermal power plants, a large amount of pebble coal will be produced, the main components of which are gangue, pyrite, etc. discharge port. A large amount of pebble coal discharged needs to be transported away in time, otherwise it will accumulate in a large amount in the coal mill, and the accumulated pebble coal will also block the air duct, causing the coal mill to malfunction and stop.

The common ways of discharge of pebble coal include artificial discharge, hydraulic discharge, and mechanical conveying discharge. At present, the amount of coal used in thermal power plants is very large, and the quality of raw coal has generally deteriorated. The amount of stones, ores and other sundries in raw coal has increased compared with before, and the emission of pebble coal has also greatly increased. In recent years, some domestic power plants have adopted pneumatic conveying systems to deal with the emission of pebble coal. Pneumatic conveying system is a material conveying method that uses airflow as a carrier to convey bulk materials at a certain speed. Compared with other material conveying methods, pneumatic conveying has high conveying efficiency, simple equipment structure and maintenance, and is conducive to automatic conveying and environmental protection. However, due to the poor quality of the coal, there are some particles with larger particle sizes (mainly ≥50mm) in the produced pebble coal. The existence of these large particles is likely to cause blockage in the pipeline, and eventually the entire pipeline The road system was paralyzed, seriously affecting production efficiency.

Contents of the invention

The object of the present invention is to solve the above problems and avoid blockage of pebble coal in the pneumatic conveying system, and proposes a pneumatic conveying feeding device equipped with a separation pipeline to realize pre-separation of large-diameter pebble coal. A large amount of pebble coal will inevitably be produced through the coal mill, and these large-grained pebble coal will be separated before entering the main conveying pipeline, thereby improving the reliability of the pneumatic conveying system.

The novel pebble coal feeding device with separation function of the present invention comprises a material collecting device 1, a feeding pipe 2, an air inlet pipeline 3, a valve 4, a separating pipeline 5, and a feeding pipeline 9. The material collecting device 1 passes through the The material pipe 2 is connected to the upper part of the front end of the intake pipeline 3, and the rear end of the intake pipeline 3 is connected to the feed pipeline 9, and the connecting position of the intake pipeline 3 and the feed pipeline 9 is provided with a downward separation pipeline 5, and the feeding The front end of the pipe 2 and the connection position of the intake pipeline 3 to the connection position of the intake pipeline 3 and the separation pipeline 5 is the feed acceleration section 8 of the feed pipeline 3; the intake pipeline 3, the separation pipeline 5, and the feeding pipeline The diameters of 9 are all d, the length of the feeding acceleration section 8 is 5d, the height difference between the intake pipeline 3 and the feeding pipeline 9 is h=gd ² /2v ² , where v is the pebble coal with a diameter of 50mm at the valve 4 The speed after passing through the feeding acceleration section 8 under the open working condition, g is the acceleration of gravity.

The present invention also includes a first discharge plate 6 and a second discharge plate 7 , and the first discharge plate 6 and the second discharge plate 7 are arranged in the separation pipeline 5 .

A connecting flange 10 is provided at the end of the feeding pipeline 9 .

In the present invention, the air flow enters horizontally along the air intake pipeline 3, and the pebble coal particles enter the air intake pipeline 3 through the material collection device 1 through the feed pipe 2. Under the action of the air flow, the pebble coal particles pass through the feeding acceleration section 8 and obtain a certain According to the theory of gas-solid two-phase fluid mechanics, the moving speed of particles with different diameters will be different, and small particles (diameter less than 50mm) will obtain greater speed. Take the particles with a diameter of 50mm when the valve 4 is fully open. When the velocity is v under working conditions, the velocity of small particles must be greater than or equal to v, and the velocity of large particles (with a diameter greater than 50 mm) is less than v. The diameter of the separation pipeline 5 is the same as that of the intake pipeline 3, both of which are d, because There is a certain height difference h in the vertical direction between the intake pipeline 3 at the front of the separation pipeline 5 and the feed pipeline 9 at the rear. After the top of the road 5, it will do a flat throwing movement. Due to the height difference between the intake pipeline 3 and the material delivery pipeline 9 h=gd ² /2v ² , where g is the acceleration of gravity, the pebble coal particles with a diameter greater than 50mm will be thrown in the vertical direction. The displacement will be greater than h, so it will all fall into the separation pipeline 5, and the pebble coal particles smaller than 50mm will be less than h because of the displacement in the vertical direction, and can pass through the separation pipeline 5 to enter the material delivery pipeline 9, and then continue to transport backwards to complete the automatic separation of particles larger and smaller than 50mm in diameter in the pebble coal particles. The separation method of the present invention is naturally completed by gravity, and the effect is stable. When unloading, the unloading plates are opened in turn, which can avoid the impact of the airflow pouring in from the bottom of the separation pipeline 5 during unloading on the stability of the system, and the unloading is completed at the same time.

Description of drawings

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

Fig. 2 is a schematic diagram of the trajectory of pebble coal particles with different particle sizes in the present invention.

In the figure: material collection device 1, feed pipe 2, air intake pipeline 3, valve 4, separation pipeline 5, first unloading plate 6, second unloading plate 7, feeding acceleration section 8, feeding pipeline 9. Connecting flange 10.

Detailed ways

As shown in Fig. 1, the new-style pebble coal feeding device with separation function of the present invention comprises material collecting device 1, feed pipe 2, air intake pipeline 3, valve 4, separation pipeline 5, feed pipeline 9, The material collection device 1 is connected to the upper part of the front end of the intake pipeline 3 through the feed pipe 2, and the rear end of the intake pipeline 3 is connected to the feeding pipeline 9, and the connecting position of the intake pipeline 3 and the feeding pipeline 9 is provided with a downward separation Pipeline 5, the front end of the connection position between feed pipe 2 and intake pipe 3 (the dotted line S position in the figure) to the connection position between intake pipe 3 and separation pipeline 5 (the dotted line E position in the figure) is the feed pipe 3 The feed acceleration section 8; the diameters of the intake pipeline 3, the separation pipeline 5, and the feed pipeline 9 are all d, the length of the feed acceleration section 8 is 5d, and the height difference between the intake pipeline 3 and the feed pipeline 9 is h =gd ² /2v ² , where v is the velocity of pebble coal with a diameter of 50mm passing through the feeding acceleration section 8 when the valve 4 is fully open, and g is the acceleration due to gravity.

The present invention also includes a first discharge plate 6 and a second discharge plate 7 , and the first discharge plate 6 and the second discharge plate 7 are arranged in the separation pipeline 5 .

A connecting flange 10 is provided at the end of the feeding pipeline 9 .

The use method and principle of the present invention are as follows: the flange 10 can be directly connected with the pneumatic conveying system, which is convenient for transforming the existing system. The pebble coal particles produced by the coal mill are transported to the material collection device 1 through the screw feeder, and enter the intake pipe 3 through the feed pipe 2. The entire pipeline is under negative pressure. The airflow inhaled by the intake pipeline 3 will make the pebble coal particles acquire a certain speed and pass through the feed acceleration section 8. The length of the feed acceleration section 8 is 5 times the diameter of the intake pipeline 3 to ensure that the particles pass through the feed acceleration section. After 8, the speed of pebble coal particles reaches a stable value,

Take the pebble coal with a diameter of 50mm and pass through the feeding acceleration section 8 under the working condition of the valve 4 fully open. To repeat; according to the theory of gas-solid two-phase flow, pebble coal particles with different diameters will obtain _different velocities. (mainly pebble coal particles with a particle size <50mm) the velocity v _{of small particles} must be greater than v.

The diameter of the separation pipeline 5 is the same as the diameter of the intake pipeline 3, which is d, because there is a certain height difference h in the vertical direction between the intake pipeline 3 at the front of the separation pipeline 5 and the feed pipeline 9 at the rear, When the pebble coal particles leave the feed acceleration section 8 of the intake pipeline 3 and enter the upper part of the separation pipeline 5, they will perform a flat throwing motion. Due to the height difference between the intake pipeline 3 and the material delivery pipeline 9 h=gd ² /2v ² , where g is the acceleration due to gravity.

Situation 1: For pebble coal particles with a diameter greater than 50mm, according to h=gd ² /2v ² , when g, d, are all constant, h and v are inversely proportional to each other. Since v is larger than v, the larger _particle The displacement of the particles in the vertical direction will also be greater than h, so they will all fall into the separation line 5 .

Situation 2: For pebble coal particles with a diameter less than 50mm, similarly, since v _{small particles} are greater than v, the vertical displacement of small particles will be less than h, and they can pass through the upper part of the separation pipeline 5 to enter the feeding pipeline 9, and then continue to transport backwards. So far, the automatic separation of particles with a diameter of 50 mm or more and below the diameter of the pebble coal particles has been completed. The separation method of the present invention is naturally completed by gravity, and the effect is stable. Unloading plates, when unloading, open the unloading plates in turn, which can avoid the impact of the airflow pouring in from the bottom of the separation pipeline 5 during unloading on the stability of the system, and complete the unloading at the same time.

Figure 2 is a schematic diagram of the trajectory of pebble coal particles with different particle sizes. In the figure, A is the trajectory curve of large particles, and B is the trajectory curve of small particles. After particles of different particle sizes enter the separation chamber, the large particles will fall into the separation chamber. Pipeline 5, small particles will enter the feeding pipeline 9 due to their high speed.

A first discharge plate 6 and a second discharge plate 7 are installed in the separation pipeline 5, and the separation pipeline 5 is divided into upper and lower parts. Once the discharge plate 6 is opened, the pebble coal falls to the lower part of the separation pipeline 5, that is, the first discharge. After completion, the first discharge plate 6 is closed immediately, and then the second discharge plate 7 at the bottom of the separation pipeline 5 is opened Unloading to the outside, that is, the second unloading, this operation avoids the influence of the airflow pouring in from the bottom of the separation pipeline 5 during the first unloading on the system stability.

Claims (3)

1. the pebble coal feeding device of a Novel belt separation function, it is characterized in that: comprise material collecting device (1), feed pipe (2), admission line (3), valve (4), separate lines (5), conveying pipeline (9), material collecting device (1) is connected to the top of admission line (3) front end by feed pipe (2), admission line (3) rear end connects conveying pipeline (9), admission line (3), conveying pipeline (9) connection location is provided with downward separate lines (5), feed pipe (2) and the front end of admission line (3) connection location are the charging accelerating sections (8) of feeding pipe (3) to admission line (3) and separate lines (5) connection location, the diameter of admission line (3), separate lines (5), conveying pipeline (9) is d, and the length of charging accelerating sections (8) is 5d, admission line (3) and conveying pipeline (9) diff-H h=gd ²/ 2v ², wherein the pebble coal of v to be diameter be 50mm is by the speed after charging accelerating sections (8) under the operating mode of valve (4) standard-sized sheet, and g is acceleration due to gravity.

2. the pebble coal feeding device of Novel belt separation function according to claim 1, is characterized in that: also comprise the first stripper (6), the second stripper (7), and the first stripper (6), the second stripper (7) are arranged in separate lines (5).

3. the pebble coal feeding device of Novel belt separation function according to claim 1, is characterized in that: conveying pipeline (9) end is provided with butt flange (10).