JPH0327448B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for preventing scattering of coal dust in outdoor coal storage areas in call centers, coal-fired power plants, etc.

(Conventional technology) Currently, Japan is trying to diversify its energy sources, and as part of this effort, coal is being reconsidered.
In particular, since coal imported from overseas contains a large amount of small particles, the scattering of coal dust from coal storage sites has become a hot topic as a pollution problem. For this reason, methods are being considered to prevent the scattering of coal dust by concealing the coal by storing it indoors or storing it in silos, but this is not practical if the amount of coal stored is large because the equipment cost would be enormous.

Therefore, outdoor coal storage is carried out in call centers, coal-fired power plants, etc. that store a large amount of coal, and the most effective method for preventing the scattering of coal dust is to store coal as shown in Japanese Patent Application Laid-Open No. 196866/1986. Water spray devices equipped with fan-shaped rotating nozzles are installed around the mountain at a fixed pitch. During weak winds, water is injected directly toward the coal storage mountain. During strong winds, the elevation angle of the nozzle is increased and water is sprayed in a nearly vertical direction, allowing the wind to A method to prevent coal dust from scattering has been adopted by scattering it toward the coal pile. However, in this method, in order to spray water over the entire long coal pile with as few water spray devices as possible, in times of weak winds, the nozzles of each water spray device are fan-shaped at a wide angle around an axis tilted with respect to the horizontal plane. Because of the rotation, the water ejected from the nozzle directly hits the sides of the coal pile on both sides of the fan-shaped motion, and the speed of the nozzle tip is also lower on both sides of the fan-shaped motion than in the center. There was a problem in that a large amount of water concentrated on specific parts of the coal pile, causing landslides.
For this reason, attempts have been made to increase the number of water spray devices and reduce the fan rotation angle of each nozzle, but in large-scale coal storage piles, equipment costs and running costs increase, so it is necessary to install more water spray devices. There has been a need for a method for preventing coal dust scattering that can solve the above-mentioned drawbacks without causing any problems.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned conventional problems and enables water to be sprayed onto the entire coal pile using a small number of water spraying devices without causing the coal pile to collapse even during weak winds. This was completed with the aim of creating a method to prevent coal dust from scattering.

(Means for Solving the Problems) The present invention includes an elevation angle changing mechanism in the fan-shaped rotation mechanism of the nozzle when discharging water toward the coal pile while rotating the nozzle of a water spraying device disposed around the coal pile in a fan shape. By incorporating this mechanism and activating this elevation angle changing mechanism when the nozzle reaches both ends of the fan-shaped rotation, the elevation angle that the water discharge surface formed by the fan-shaped rotation of the nozzle makes with respect to the horizontal plane can be changed at the center of the fan-shaped rotation. It is characterized by being constant and gradually increasing on both sides of the fan-shaped motion.

Next, the present invention will be described in detail with reference to the illustrated embodiment. In FIG. 1, 1 is a coal pile, and 2 is a large number of water discharging devices arranged around it. As shown in FIGS. 2 and 3, each water discharging device 2 is equipped with a pipe 5 that can be rotated by a small angle around a horizontal support shaft 3 by a first motor 4, and has an arm-shaped section attached to this pipe 5. 6 are arranged in series, and a shaft part 8a of an L-shaped nozzle 8 is attached to this arm-shaped part 6, which rotates in a fan shape around the central axis of the arm-shaped part 6 by a second motor 7. It is. This nozzle 8 is operated by a control mechanism such as a limit switch (not shown) and repeats a fan-shaped rotational movement around the inclined arm-shaped part 6 by a fan-shaped rotation mechanism consisting of a second motor 7, as shown in FIG. The high-pressure water supplied from the pipe 5 is discharged toward the coal pile 1, and as shown in Fig. 3, the angle of elevation of the water discharge surface is maintained at a constant value α, as in the past.

However, in the present invention, a detector for the rotation angle of the nozzle 8, such as a limit switch 9, is attached to the base of the nozzle 8, and when the nozzle 8 reaches a position just before the water discharged on both sides of the fan-shaped movement directly hits the coal pile 1, By activating the elevation angle changing mechanism consisting of the first motor 4, the arm-shaped portion 6 is gradually swung upward as shown by the solid line in FIG. The arm-shaped part 6 is gradually swung downward, and the arm-shaped part 6 is returned to the angle shown by the imaginary line in FIG. 3 near the position where the arm-shaped part 6 first started to be swung upward. In this way, the elevation angle changing mechanism is incorporated into the fan-shaped rotation mechanism of the nozzle, and when the nozzle reaches both ends of the fan-shaped rotation, this elevation angle changing mechanism is activated to gradually swing the arm-shaped portion 6 upward at both sides of the fan-shaped rotation. When the nozzle 8 is rotated, the angle of elevation of the water discharge surface X formed by the fan-shaped rotation of the nozzle 8 with respect to the horizontal plane is larger than α and becomes a gradually larger value β toward both sides, and after the nozzle 8 is reversed, it increases from β to We will return to α. As a result, as shown in Fig. 4, the water discharge from the nozzle 8 gradually rises nearly vertically on both sides of the fan-shaped movement, and returns to the original water discharge angle as it returns to the center. Even when the water stream approaches the ridgeline of the coal pile 1, it does not directly hit the coal pile 1 unlike in the past, and the water discharge flow moves upward to avoid direct impact with the coal pile 1 while discharging water onto the top surface of the coal pile 1. will continue. Therefore, according to the present invention, the water discharge width of each nozzle 8 can be made sufficiently larger than when simply reducing the rotation angle width of the fan-shaped motion, and moreover, water can be discharged within the fan-shaped rotation plane with a constant elevation angle α. There is no risk of landslides, unlike the conventional method that requires

When the wind is strong, the first motor 4, which is an elevation angle changing mechanism, is operated to raise the nozzle 8 to an elevation angle of 75° to 90°, as in the past, and the nozzle is rotated in a fan-shaped manner by a fan-shaped rotation mechanism within a nearly vertical plane. Then water is sprayed and the wind pressure scatters it towards the coal storage pile 1. At this time, even if the limit switch 9 is operated, there is no need to operate the first motor 4, which is the elevation angle changing mechanism. Note that the first motor 4 and the second motor 7 are preferably speed controllable, and in addition to using an electric motor, a fluid pressure drive device such as a water turbine or a rotary actuator can also be used.

Furthermore, the method of gradually increasing the angle of elevation of the water discharge surface formed by the fan-shaped rotation of the nozzle with respect to the horizontal plane on both sides of the fan-shaped movement is not necessarily limited to the above method. Nozzles 8 are installed on both sides of the fan-shaped rotating surface.
A guide plate is installed to deflect the water flow upward, and while the nozzle 8 is rotated in a fan shape within a fixed plane, only the direction of the water flow is deflected, thereby changing the angle of elevation that the fan-shaped rotating surface of the nozzle makes with respect to the horizontal plane. A similar effect can also be produced. In this case, the guide plate constitutes an elevation angle changing mechanism.

(Effects of the Invention) As is clear from the above description, the present invention incorporates an elevation angle changing mechanism into the fan-shaped rotation mechanism of the nozzle.
By activating this elevation angle changing mechanism when the nozzle reaches both ends of the fan-shaped rotation, the elevation angle that the water discharge surface formed by the fan-shaped rotation of the nozzle makes with respect to the horizontal plane is gradually increased at both ends of the fan-shaped rotation. This prevents the water spray from directly hitting the coal pile during weak winds, and since each nozzle can have the same wide water spray width as before, there is no need to install additional water spray equipment. This has the advantage of being able to perform water injection using wind pressure, similar to conventional methods. Therefore, the present invention greatly contributes to the development of industry as a coal dust scattering prevention method that solves the conventional problems.

[Brief explanation of drawings]

Fig. 1 is a layout diagram of the water discharging device in the present invention, Fig. 2 is a front view showing an example of the water discharging device used in the present invention, Fig. 3 is a side view thereof, and Fig. 4 is a diagram showing the relationship between the water discharging surface and the coal storage pile. FIG. 3 is a perspective view showing the relationship. 1: Coal storage pile, 2: Water discharge device, 8: Nozzle, X:
Water surface.

Claims (1)

[Claims] 1. When discharging water toward the coal pile while rotating the nozzle of the water spray device arranged around the coal pile in a fan-shaped manner, an elevation angle changing mechanism is incorporated into the fan-shaped rotation mechanism of the nozzle so that the nozzle comes to both ends of the fan-shaped rotation. Sometimes, by operating this elevation angle changing mechanism, the angle of elevation that the water discharge surface formed by the fan-shaped rotation of the nozzle makes with respect to the horizontal plane is constant in the center of the fan-shaped movement, and gradually increases on both sides of the fan-shaped movement. A method for preventing scattering of coal dust.