JP2015034639A - Combustion generation ash mass removal method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustion generation ash mass removal method capable of easily, safely and surely removing a combustion generation ash mass comprising coal ash adhering to a coal combustion facility, such as a boiler, in a coal combustion thermal power plant.SOLUTION: In a combustion generation ash mass removal method in which a ball is launched from a separate place toward a combustion generation ash mass adhering to a coal combustion facility by a launching device, the combustion generation ash mass is torn off from the coal combustion facility by collision energy of the ball, and thereby the combustion generation ash mass is removed, the launching device includes a launching nozzle, and the ball is launched from the launching nozzle with compressed air.

Description

  The present invention is a combustion product ash lump removal method, and in particular, can easily and safely remove a combustion product ash lump composed of coal ash attached to a coal combustion facility such as a boiler in a coal fired thermal power plant. The present invention relates to a method for removing combustion product ash mass.

  For example, as shown in FIG. 6, a coal-fired thermal power plant pulverizes coal into pulverized coal by a coal pulverization mill 11 and injects the pulverized coal from a combustion burner 13 into a combustion furnace 12 of a boiler as a coal combustion facility. The water flowing in the boiler water pipe 14 piped in the combustion furnace 12 is heated, and the turbine is rotated by the obtained steam to generate power. The combustion exhaust gas from the combustion furnace 12 is dissipated from the chimney 17 to the atmosphere via the flue gas desulfurization device 15 and the dust collector 16.

  Thus, since the boiler of the coal fired thermal power plant burns pulverized coal in the combustion furnace 12, combustion generated ash made of coal ash adheres to the outer wall of the boiler water pipe 14. This combustion product ash gradually grows with the operation of the boiler and becomes a hard and heavy combustion product ash mass. When combustion-generated ash mass adheres to the outer wall of the boiler water pipe 14 and grows greatly, the following problems occur.

  Periodic inspection of the boiler is carried out with a scaffold in the combustion furnace 12, but during the periodic inspection, combustion generated ash lump attached to the outer wall of the boiler water pipe 14 may fall and hit a worker, causing a serious injury. is there.

  Thus, an example of a combustion product ash lump removal method for solving this problem is disclosed in Patent Document 1 (Japanese Patent No. 40111448). Hereinafter, this combustion product ash lump removal method is referred to as a conventional combustion product ash lump removal method and will be described with reference to the drawings.

  FIG. 7 is a schematic cross-sectional view showing a launching device used in a conventional combustion product ash lump removal method.

  As shown in FIG. 7, in the conventional combustion product ash lump removal method, a kneaded product of combustion product ash composed of 30 to 80 mesh coal ash and water collected in coal combustion equipment such as a boiler is put in a mold. Filling, pressurizing, and drying forms a spherical combustion-generated ash ball 18 having a diameter of about 60 mm, and supplies the combustion-generated ash ball 18 to a launching device 20 configured to rotate a pair of rollers 19 at high speed by a motor. Then, the combustion generated ash ball 18 is sandwiched between the rollers 19 and sent out so that the combustion generated ash ball 18 is directed to the combustion generated ash mass attached to the outer wall of the boiler water pipe of the boiler as a coal combustion facility. Thus, the combustion ash mass is dropped from the outer wall of the boiler water pipe by the collision energy of the combustion ash balls 18 and removed.

  Even in an incinerator or a combustion furnace as a coal combustion facility other than a boiler, the attached combustion product ash mass can be removed by a conventional combustion product ash mass removal method.

Japanese Patent No. 40111448

  According to the above conventional combustion product ash lump removal method, from a place away from the combustion product ash lump attached to the coal combustion facility, the observation window where the launcher is installed is sufficiently large, the combustion product ash lump is not hard, etc. Can be removed to some extent, however, there are the following problems.

  The firing device 20 configured to rotate the pair of rollers 19 at a high speed by a motor causes the combustion-generated ash balls 18 to be fired toward the combustion-generated ash mass at a speed of about 100 to 200 km / h. In the case of a hard or soft baseball, it is possible to fire the ball at such a speed. However, the combustion-generated ash ball 18 is harder than the baseball, has a small friction coefficient, and the ball 18 Because of the point contact between the roller 19 and the roller 19, the frictional force is further reduced. Therefore, it was found that a speed of about 130 km / h was the limit and a speed higher than that could not be expected.

  Thus, in the conventional combustion product ash lump removal method, the combustion product ash ball 18 cannot be fired at high speed, and the combustion product ash ball 18 is fired from between the pair of rollers 19 by the frictional force generated by point contact. The combustion generated ash balls 18 are poorly controlled, and even if the target combustion generated ash lump can be hit, there is a possibility that the combustion generated ash lump cannot be reliably dropped and removed.

  Accordingly, an object of the present invention is to provide a combustion product ash lump removal method capable of easily and safely removing combustion product ash lump composed of coal ash adhering to coal combustion facilities such as boilers in a coal fired thermal power plant. It is to provide.

  The present invention has been made to achieve the above object, and is characterized by the following.

  According to the first aspect of the present invention, a ball is fired from a location away from the combustion generated ash lump attached to the coal combustion facility, and the combustion generated ash lump is dropped from the coal combustion facility by the collision energy of the ball. In the method for removing a combustion product ash lump to be removed, the ball is fired by compressed air from a firing nozzle directed to the combustion product ash lump.

  The invention described in claim 2 is characterized in that, in the invention described in claim 1, the ball is made of a mixture containing non-shrinkage cement and sand.

  The invention described in claim 3 is characterized in that, in the invention described in claim 1, the ball is made of a mixture containing non-shrinkage cement, sand and lime.

  The invention according to claim 4 is the invention according to claim 1, wherein the balls are mixed with non-shrinkage cement, sand, and water in a weight ratio of 1: 3 to 6: 0.7 to 0.9. It is characterized by manufacturing.

  The invention according to claim 5 is the invention according to claim 1, wherein the ball is made of non-shrinkage cement, sand, lime, and water in a weight ratio of 1: 1.5 to 2.0: 1.0 to 1. .5: It is characterized by being manufactured by mixing at a ratio of 1.2 to 1.5.

  The invention described in claim 6 is characterized in that, in the invention described in any one of claims 1 to 5, the firing speed of the ball is in the range of 210 km / h to 250 km / h. is there.

According to a seventh aspect, in the invention according to any one of claims 1-6, the compressive strength of the balls, characterized in that in the range of 10 N / mm ² of 30 N / mm ² Is.

  The invention according to an eighth aspect is characterized in that, in the invention according to any one of the first to seventh aspects, the tip of the firing nozzle is curved.

  The invention described in claim 9 is characterized in that, in the invention described in claim 8, the firing nozzle is rotatable about an axis of the firing nozzle.

  According to a tenth aspect of the present invention, in the invention according to any one of the first to seventh aspects, an impact plate with which the ball hits the tip of the firing nozzle is inclined with respect to the firing direction of the ball. It is characterized by being attached.

  The invention described in claim 11 is characterized in that, in the invention described in claim 10, the firing nozzle is rotatable around the axis of the firing nozzle together with the collision plate.

  A twelfth aspect of the invention is characterized in that, in the invention according to any one of the first to eleventh aspects, the ball has an uneven surface.

  The invention according to claim 13 is the invention according to any one of claims 1 to 12, wherein the firing nozzle is inserted into an opening formed in a wall surface of the coal combustion facility, and the ball is burned. It is characterized by firing toward the generated ash mass.

  According to the present invention, there is provided a combustion product ash lump removal method capable of easily and securely removing combustion product ash lump composed of coal ash adhering to coal combustion facilities such as boilers in a coal fired thermal power plant. be able to.

It is a schematic front view which shows the combustion production ash lump removal apparatus for implementing this invention. It is a schematic plan view which shows the removal state of the combustion production ash lump by the combustion production ash lump removal apparatus for implementing this invention. It is a schematic front view which shows the combustion generated ash lump removal apparatus for implementing this invention provided with the discharge nozzle with which the front-end | tip part curved. It is a schematic front view which shows the combustion production ash lump removal apparatus for implementing this invention provided with the discharge nozzle with which the collision board was attached to the front-end | tip. It is a front view which shows the ball | bowl with which the unevenness | corrugation was formed on the surface. It is a schematic sectional drawing which shows the boiler of a coal fired thermal power plant. It is a schematic sectional drawing which shows the launch device used for the conventional combustion production ash lump removal method.

  An embodiment of a combustion product ash lump removing apparatus for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic front view showing a combustion product ash lump removing device for carrying out the present invention.

  In FIG. 1, reference numeral 1 denotes a main body of the combustion product ash lump removing device, which has a supply port 3 for a ball 2 described later. The main body 1 is supplied with compressed air from the outside. Reference numeral 4 denotes an opening / closing valve. By opening and closing the opening / closing valve 4 instantaneously, compressed air is sent into a nozzle 5 attached to the tip of the main body 1. Thus, the ball 2 supplied from the supply port 3 into the main body 1 is launched from the nozzle 5 toward the combustion product ash mass by compressed air.

  The ball 2 is formed in a spherical shape with a diameter of about 30 mm to 80 mm, for example, 50 mm, and is made of a mixture of non-shrinkage cement and sand. 6: 0.7 to 0.9, preferably 1: 3: 0.7.

  The firing speed of the ball 2 is in the range of 210 km / h to 250 km / h, preferably in the range of 210 km / h to 220 km / h. The firing speed of the ball 2 can be easily adjusted by adjusting the pressure of the compressed air. By firing the ball 2 with compressed air, it is possible to obtain a high firing speed that could not be obtained with a roller-type firing device such as the conventional combustion-generated ash lump removal method, and to fire the ball 2 through the nozzle 5. In addition, the control of the ball 2 can be remarkably improved. As a result, the ball 2 can hit the target combustion product ash mass accurately, and the combustion product ash mass can be reliably dropped and removed because of the high speed.

  The ball 2 is made of a mixture containing non-shrinkage cement and sand. The ball 2 is produced by filling a mixture of non-shrinkage cement, sand and water into a molding die coated with a lubricant. Although it is pressed and dried, a normal cement does not yield a ball 2 having a desired diameter due to shrinkage after drying. On the other hand, if non-shrinkage cement is used, shrinkage due to drying can be suppressed to the maximum, so that a ball 2 having a desired diameter can be obtained. By using the ball 2 having a desired diameter, the gap between the ball 2 and the nozzle 5 can be minimized, so that the firing speed of the ball 2 can be easily adjusted.

In addition, the hardness of the combustion product ash lump varies greatly depending on the type of coal to be burned. If the ball 2 is not used, the combustion-generated ash mass cannot be reliably dropped and removed. That is, the combustion-generated ash balls made of coal ash described above have a lower strength than the balls 2 made of a mixture of non-shrinkable cement and sand, and the hard combustion-generated ash mass cannot be reliably dropped and removed. Compressive strength of the balls is in the range from 10 N / mm ² of 30 N / mm ^2, preferably, a good range of 20 N / mm ² of 25 N / mm ^2.

  Furthermore, the combustion-generated ash balls made of coal ash described above can form the balls accurately into a spherical shape even if the kneaded product of coal ash and water is pressed and molded because the coal ash contains many bubbles. I can't. Therefore, with combustion-generated ash balls made of coal ash, the balls cannot be fired at high speed through the nozzle with compressed air.

In addition, when a ball with a soft combustion product ash mass and a small compressive strength is required, the material of the ball 2 may be a mixture containing non-shrinkage cement, sand and lime. When lime is added, adjustment to weaken the compressive strength of the ball can be easily performed while maintaining the moldability of the ball. In this case, the non-shrinkable cement, sand, lime and water are used in a weight ratio of 1: 1.5 to 2.0: 1.0 to 1.5: 1.2 to 1.5, preferably 1: 2. : Mixed at a ratio of 1.5: 1.5. Compressive strength of the balls is in the range from 10 N / mm ² of 30 N / mm ^2, preferably in the range from 10 N / mm ² of 20 N / mm ² is good.

  In order to remove the combustion product ash mass composed of coal ash adhered to the boiler water pipe in the coal fired thermal power plant, for example, by the combustion product ash mass removal device for carrying out the present invention configured as described above, As shown in FIG. 2, the main body 1 of the combustion product ash mass removing device is installed in the vicinity of the observation window 7 (opening) provided in the combustion furnace 6 of the boiler, and the nozzle 5 is inserted into the combustion furnace 6 from the observation window 7. It is inserted and directed to the combustion product ash mass 9 attached to the boiler water pipe 8 arranged on the furnace wall. As the boiler water pipe 8, there is a suspended boiler water pipe 8a disposed at a position away from the furnace wall.

  Then, if the on-off valve 4 is opened and the ball 2 is fired at a high speed with compressed air, the ball 2 accurately collides with the combustion-generated ash mass 9, and the combustion-generated ash mass 9 is caused by the collision energy at this time. It can be easily and reliably removed from the boiler water pipe 8 and removed. Moreover, the combustion generated ash mass 9 can be removed and removed from a remote location, which is safe.

  Further, as shown in FIG. 2, if a laser beam sighting device 21 and an in-furnace camera 22 are attached to the tip of the nozzle 5 and a camera monitor 23 is installed outside the furnace, the removal and removal of the combustion product ash mass 9 can be further performed. While being able to carry out correctly, it becomes possible to grasp | ascertain reliably the present condition of dropping-off and removal work of the combustion ash lump 9.

  Since the width (W) of the observation window 7 provided in the combustion furnace 6 is usually about 100 mm, the movable range of the nozzle 5 inserted into the observation window 7 is narrow, and depending on the position of the target combustion product ash mass 9 In some cases, the combustion-generated ash mass 9 may come off from the extension of the center line of the nozzle 5. In this case, if the tip of the nozzle 5 is curved as shown in FIG. 3 or a collision plate 10 made of rubber or the like is attached to the tip of the nozzle 5 as shown in FIG. Even if (W) is narrow, the flight trajectory of the ball 2 can be accurately directed to the target combustion-generated ash mass 9.

  In addition, when the front-end | tip part of the nozzle 5 is curved, if the nozzle 5 can be rotated around the axis line, the position of the launch port of the nozzle 5 can be changed 360 ° up and down and left and right. Even when the collision plate 10 is provided at the tip of the nozzle 5, if the nozzle 5 can be rotated about its axis, the position of the launch port of the nozzle 5 can be changed.

  Furthermore, if the nozzle 5 can be expanded and contracted, the position of the launch port of the nozzle 5 can be changed while avoiding the closed door of the observation window that is an obstacle in the vicinity of the observation window. The ash mass 9 can be made to collide.

  In addition, when the observation window 7 is not installed, or when the observation window 7 is installed, the combustion generated ash mass 9 can be dropped and removed by entering the combustion furnace 6. The combustion product ash lump removal device can be carried into the combustion furnace 6 to perform the work.

  Further, as shown in FIG. 5, if an uneven portion is formed on the surface of the ball 2, the ball 2 bites into the combustion product ash mass 9 when the ball 2 collides with the combustion product ash mass 9. Dropping and removing efficiency of the lump 9 is improved. The uneven portion formed on the surface of the ball 2 is formed by forming a protrusion on the surface of the ball 2 or forming a recess on the surface of the ball 2.

  The above is the case where the present invention is applied to the removal of combustion ash mass composed of coal ash adhering to the boiler water pipe in a coal fired thermal power plant, but the removal of combustion product ash other than coal ash, mass incinerator or combustion Of course, it can be applied to other combustion equipment such as a furnace.

1: Main unit 2: Ball 3: Supply port 4: Open / close valve 5: Nozzle 6: Combustion furnace 7: Peep window 8: Boiler water pipe 8a: Boiler water pipe 9: Combustion ash mass 10: Collision plate 11: Coal crushing mill 12: Combustion furnace 13: Combustion burner 14: Boiler water pipe 15: Flue gas desulfurization device 16: Dust collector 17: Chimney 18: Combustion ash ball 19: Roller 20: Launcher 21: Laser beam sight 22: In-furnace camera 23: Camera monitor

According to the first aspect of the present invention, a ball is fired from a location away from the combustion-generated ash mass attached to the coal combustion facility, and the combustion-generated ash mass is dropped from the coal combustion facility by the collision energy of the ball. In this method, the ball is fired by compressed air from a firing nozzle directed to the combustion product ash lump, and the firing speed of the ball is within a range of 210 km / h to 220 km / h. , compressive strength of the balls are those having a particular characteristic in a range from 20 N / mm ² of 25 N / mm ^2.

The invention described in claim 6 is characterized in that, in the invention described in any one of claims 1 to 5, the tip of the firing nozzle is curved .

A seventh aspect of the invention is characterized in that, in the sixth aspect of the invention, the firing nozzle is rotatable about the axis of the firing nozzle .

According to an eighth aspect of the present invention, in the invention according to any one of the first to fifth aspects, an impact plate with which the ball hits the tip of the firing nozzle is inclined with respect to the firing direction of the ball. It is characterized by being attached .

The invention according to claim 9 is characterized in that, in the invention according to claim 8, the firing nozzle is rotatable together with the collision plate around an axis of the firing nozzle .

The invention described in claim 10 is characterized in that, in the invention described in any one of claims 1 to 9 , the ball has irregularities formed on a surface thereof.

The invention according to claim 11 is the invention according to any one of claims 1 to 10 , wherein the firing nozzle is inserted into an opening formed in a wall surface of the coal combustion facility, and the ball is inserted into the opening. It is characterized by being fired toward the combustion product ash mass .

According to the first aspect of the present invention, a ball is fired from a location away from the combustion-generated ash mass attached to the coal combustion facility, and the combustion-generated ash mass is dropped from the coal combustion facility by the collision energy of the ball. In this method, the ball is fired by compressed air from a firing nozzle directed to the combustion product ash lump, and the firing speed of the ball is within a range of 210 km / h to 220 km / h. , compressive strength of the balls, and in the range from 20 N / mm ² of 25 N / mm ^2, 1 the ball and no shrinkage cement and sand and lime and water in a weight ratio: 1.5 to 2.0: It is characterized by being produced by mixing at a ratio of 1.0 to 1.5: 1.2 to 1.5 .

The invention described in claim 2 is characterized in that, in the invention described in claim 1, the tip of the firing nozzle is curved .

A third aspect of the invention is characterized in that, in the second aspect of the invention, the firing nozzle is rotatable around an axis of the firing nozzle .

According to a fourth aspect of the present invention, a ball is fired from a location away from the combustion-generated ash mass attached to the coal combustion facility, and the combustion-generated ash mass is dropped from the coal combustion facility by the collision energy of the ball. In this method, the ball is fired by compressed air from a firing nozzle directed to the combustion product ash lump, and the firing speed of the ball is within a range of 210 km / h to 220 km / h. , compressive strength of the balls, and in the range from 20 N / mm ² of 25 N / mm ^2, wherein the tip of the firing nozzles, impingement plate where the ball hits are attached inclined with respect to the firing direction of the ball It has the characteristic in being.

The invention described in claim 5 is characterized in that, in the invention described in claim 4 , the firing nozzle is rotatable together with the collision plate around an axis of the firing nozzle .

The invention described in claim 6 is characterized in that, in the invention described in any one of claims 1 to 5, the ball has an uneven surface .

The invention according to claim 7 is the invention according to any one of claims 1 to 6, wherein the firing nozzle is inserted into an opening formed in a wall surface of the coal combustion facility, and the ball is inserted into the opening. It is characterized by being fired toward the combustion product ash mass .

Claims (13)

A combustion-generated ash lump removal method of firing a ball from a place away from a combustion-generated ash lump attached to a coal combustion facility and removing the combustion-generated ash lump from the coal combustion facility by removing the collision energy of the ball In
A method of removing combustion product ash mass, wherein the ball is fired by compressed air from a firing nozzle directed to the combustion product ash mass.   2. The combustion product ash mass removing method according to claim 1, wherein the balls are made of a mixture containing non-shrinkage cement and sand.   2. The combustion product ash mass removing method according to claim 1, wherein the ball is made of a mixture containing non-shrinkage cement, sand and lime.   The combustion generation according to claim 1, wherein the balls are produced by mixing non-shrinkage cement, sand and water in a weight ratio of 1: 3 to 6: 0.7 to 0.9. Ash lump removal method.   The ball is produced by mixing non-shrinkage cement, sand, lime and water in a weight ratio of 1: 1.5 to 2.0: 1.0 to 1.5: 1.2 to 1.5. The combustion generated ash lump removal method according to claim 1, wherein:   6. The combustion product ash mass removing method according to claim 1, wherein the ball firing speed is in a range of 210 km / h to 250 km / h. Compressive strength of the balls, characterized in that it is in the range of 10 N / mm ² of 30 N / mm ^2, the combustion products ash loosening method according to either one of claims 1 to 6.   The combustion-generated ash lump removal method according to any one of claims 1 to 7, wherein a tip portion of the firing nozzle is curved.   The method of claim 8, wherein the firing nozzle is rotatable around an axis of the firing nozzle.   The combustion according to any one of claims 1 to 7, wherein a collision plate to which the ball hits is attached to a tip of the firing nozzle so as to be inclined with respect to a firing direction of the ball. Generated ash lump removal method.   11. The combustion product ash mass removing method according to claim 10, wherein the firing nozzle is rotatable about the axis of the firing nozzle together with the collision plate.   The method for removing a combustion-generated ash mass according to any one of claims 1 to 11, wherein the ball has irregularities formed on a surface thereof.   13. The method according to claim 1, wherein the firing nozzle is inserted into an opening formed on a wall surface of the coal combustion facility, and the ball is fired toward the combustion-generated ash mass. The method for removing the combustion product ash mass described in 1.

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