JPH0451439B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a large-sized coal storage silo, and more particularly to a coal storage silo having a heat dissipation pipe for preventing spontaneous combustion of coal.

(Background technology) When storing large amounts of coal in silos for long periods of time, preventing spontaneous combustion of the coal is an important issue that cannot be avoided.

The temperature rise of stored coal and the danger of spontaneous combustion are mainly caused by the oxidation reaction of the coal, which is also adversely affected by the fact that the thermal conductivity of coal is low and it tends to accumulate heat.

Traditionally, when coal is piled up in the open, it is hard to get oxygen into the coal by compacting it tightly or covering it with a sheet, or by sprinkling water on it occasionally or digging it up to dissipate the accumulated heat. Fire prevention measures were implemented.

In addition, in the case of coal storage silos, there is a method of measuring the temperature inside the stored coal each time using temperature measurement cables, etc., and when a temperature rise is detected, it is immediately discharged, or there is a method of injecting inert gas. −
199597, Japanese Patent Laid-Open No. 56-41187), but these methods were time-consuming and troublesome.

By the way, as a result of performing a spontaneous combustion simulation on a cylindrical silo, the following was found.

That is, in the case of conical hopper-shaped coal storage silo 1,
As shown in FIG. 1A, the temperature rise in the upper part of the stored coal 2 near the center 3 at a constant depth is particularly large. In addition, in the case of central cone-shaped coal storage silo 4,
As shown in FIG. 1B, the temperature rise in the annular portion 5 of a constant radius surrounding the center of the upper constant depth of the stored coal 2 is particularly large.

For example, in the case of the central cone-shaped coal storage silo 4, the temperature of the shaded annular portion 5 is 90 days.
80℃ was detected.

Therefore, conversely speaking, in the case of a coal storage silo, all risks of spontaneous combustion can be eliminated by cooling only the areas where the temperature rise is particularly large, as identified above.

(Objective of the Invention) Therefore, the object of the present invention is to apply the results of the above-mentioned spontaneous combustion simulation to prevent spontaneous combustion of stored coal reliably and inexpensively without requiring any special effort on a daily basis. The purpose of the present invention is to provide a coal storage silo with an improved configuration.

(Structure and Effects of the Invention) In order to achieve the above object, the coal storage silo of the present invention has metal heat dissipating material with high thermal conductivity in the portion 3 or 5 where the heat generation and temperature rise of the stored coal 2 is particularly large. A pipe 6 or 17 is installed, and the heat dissipation pipe is passed vertically through the center of the central cone-shaped coal storage silo 4 through a part where the heat generation and temperature rise of the stored coal 2 is particularly large, or a conical hopper is installed. A non-penetrating metal outer tube 17b with a high thermal conductivity has a length that extends from the upper end of the coal storage silo 1 to at least the part where the heat generation and temperature rise of the stored coal is particularly large. The inner tube 17a is arranged concentrically at the center of the outer tube 17b, and the double tube structure has an opening 17a' near the bottom of the outer tube 17b. Each of the pipes 6 or 17 is characterized in that heat absorbing fins 10 or 19 are provided on the outer circumferential surface of the pipe 6 or 17, projecting radially toward a portion where the heat generation and temperature rise of the stored coal is particularly large.

In other words, through the heat dissipation pipe, heat is constantly removed from areas where the heat generation and temperature rise is particularly large, and the heat is radiated to the outside, thereby preventing dangerous temperature rises.

Therefore, the risk of spontaneous combustion can be reliably prevented from occurring, and it does not require any special effort or trouble on a daily basis.

In the case of a central cone-shaped coal storage silo, the heat dissipation pipe is installed to penetrate the coal storage silo in the vertical direction, and its lower end is communicated with the outside air intake under the center cone, so that the heat dissipation effect is achieved through so-called natural ventilation. Therefore, running costs are unnecessary,
Economical.

In addition, in the case of a conical hopper type coal storage silo, the heat dissipation pipe is installed as a non-penetrating pipe with a length extending from the upper end of the silo to at least the part where the temperature rise of the stored coal is particularly large, so the purpose of cooling is achieved by natural ventilation. can be achieved.

In addition, since the heat dissipation pipe is provided with heat absorption fins 10 or 19 protruding from its outer periphery, the efficiency of heat exchange is increased.

Next, the embodiment illustrated in FIG. 2 and subsequent figures will be described.

(First Embodiment) In FIG. 2, reference numeral 6 denotes a heat dissipation pipe installed to penetrate the center of the central cone-shaped coal storage silo 4 in the vertical direction. The heat dissipation pipe 6 is
It is made of metals with high thermal conductivity such as iron, copper, and aluminum. The lower end of the heat radiation pipe 6 is communicated with the hollow part 8 of the central cone 7. The hollow portion 8 is provided with an outside air intake port 9 that opens laterally.

Therefore, the cold air flowing in from the outside air intake port 9 rises in the heat dissipation pipe 6 due to the so-called chimney effect.
It is dissipated to the outside from the upper end.

As shown in FIG. 1B above, in the case of the central cone-shaped coal storage silo 4, the temperature rise in the annular portion 5 of a certain radius surrounding the center of the upper part of the stored coal 2 at a certain depth is particularly large; In addition to being transmitted to the heat radiation pipe 6 and conducted through the heat radiation pipe 6, the heat is absorbed by the airflow rising through the heat radiation pipe 6,
Heat is radiated outside the silo. That is, a constant heat transfer path is formed.

Therefore, there is no time for heat to build up in the annular portion 5 and cause the temperature to rise, and the temperature rise is suppressed to a low range, so that the risk of spontaneous combustion can be reliably prevented.

(Second Embodiment) In FIG. 3, reference numeral 10 indicates the outer periphery of a heat dissipation pipe 6 installed so as to penetrate vertically through the center of the central cone-shaped coal storage silo 4, where the temperature rise in the stored coal 2 is particularly large. This is an endothermic fin that projects toward the annular portion 5 shown in FIG. 1B.

The number, shape, and arrangement of the heat absorbing fins 10 are determined and provided according to the position, shape, and size of the temperature increasing portion (annular portion 5) determined as a result of simulation, and the heat dissipating fins 10 are provided as shown in FIG. 6
In this case, the heat absorbing fins 10 have a configuration in which four pieces of the same shape are provided in four diametrical directions. In addition, the heat dissipation pipe 10 shown in FIG.
It has heat radiation fins 11...

Therefore, the heat trapped in the stored coal 2 is absorbed and removed much more efficiently than when it is transmitted through the coal through the heat absorption fins 10. Further, the heat transmitted to the heat radiation pipe 6 is highly efficiently transmitted to the airflow rising inside the heat radiation pipe 6 via the heat radiation fins 11, and is then radiated outside the silo.

In addition, 12 in the figure is a temperature sensor attached to the heat absorption fin 10, and the temperature inside the stored coal 2 can be monitored by this.

For example, if an exhaust fan is installed at the upper end of the heat radiation pipe 6 or a fan is installed at the outside air intake port 9, and a temperature rise in the stored coal 2 is still detected by the temperature sensor 12 even though the heat is radiated by natural draft wind. , an exhaust fan or blower can be activated to force ventilation and provide strong cooling.

(Third Embodiment) FIGS. 5 and 6 show a water-cooled forced cooling system. In the figure, reference numeral 13 denotes a water-cooled pipe attached to the outer surface of the heat radiation pipe 6 and the heat absorption fin 10. This water-cooled pipe 13 forms a water-cooled closed circuit together with a circulation pump 14 and a radiator 15.

In other words, the cooling water in the water tank 16 is circulated by the pump 1.
4 and rises in the water-cooled pipe 13 to remove the heat trapped in the stored coal 2. Thus, the heat of the heated water is radiated by the radiator 15 and returned to the water tank 16 as cooling water.

Water has a much larger heat capacity than air, and can perform strong forced cooling of the stored coal 2. Therefore, the danger of spontaneous combustion of coal can be more reliably prevented.

Note that this water cooling method is used in combination with air cooling by the natural ventilation of the heat dissipation pipe 6, and it is preferable to perform water cooling only when the temperature rise of the coal cannot be suppressed even with air cooling.

(Fourth Embodiment) In FIG. 7, reference numeral 17 is a heat dissipation pipe, which is located at the center of the conical hopper-type coal storage silo 1 and extends from the upper end of the silo to at least the stored coal 2.
It is installed as a so-called non-penetrating type, with a length sufficient to reach a portion where the temperature rise is particularly large, for example, near the center 3 shown in FIG. 1A. That is, the lower part of the silo is formed as a conical hopper 18, making it difficult to penetrate the heat radiation pipe. However, heat dissipation pipe 17
It can be installed as a penetrating type, with the lower part of the silo penetrating the circumferential body (side) of the silo.

This heat dissipation pipe 17 is also made of iron, which has high thermal conductivity.
It is made of metals such as copper and aluminum.

In the case of this heat radiation pipe 17 as well, in addition to heat conduction, the stored coal 2 can be cooled by an air cooling method using forced ventilation or a water cooling method using cooling water circulation.

Thus, the temperature rise of the coal stored in the conical hopper-shaped silo 1 is particularly large near the center 5 (the first
The heat shown in Figure A) is constantly removed through the heat radiation pipe 17. Therefore, the danger of spontaneous combustion of the coal 2 can be reliably prevented.

(Fifth Embodiment) In FIG. 8, reference numeral 19 denotes a heat absorption fin protruding from the outer periphery of the heat radiation pipe 17 near the center 3 (FIG. 1) where the temperature rise of the stored coal 2 is particularly large.

The structural details of this heat dissipation pipe 17 are as shown in FIGS. 9 and 10, and include an inner pipe 17a made of a heat insulating material (or covered with a heat insulating material) and a material made of a material with good thermal conductivity. It has a double tube structure in which the outer tube 17b and the outer tube 17b are arranged concentrically (FIG. 10). Inside/
The outer tubes 17a and 17b are integrally connected by a support plate 20 that also serves as a heat radiation fin. Inner tube 17
The lower end 17a' of a is opened at a constant height position directly above the lower bottom 17b' of the outer tube 17b. Same upper end 17
a'' is opened and protrudes outward from the outer tube 17b at a position near the upper end of the outer tube 17b.

That is, when the outer tube 17b is heated by the heat generated by the stored coal 2, the air inside the outer tube 17b increases in temperature and flows upward. However, the air inside the inner tube 17a made of a heat insulating material remains cool and flows downward. In this way, the air that flows in through the inner pipe 17a and descends rises along the outer pipe 17b and flows out to the outside, creating a so-called chimney effect (natural draft), thereby producing an air cooling effect.

Therefore, the risk of spontaneous combustion of the stored coal 2 can be reliably prevented.

(Other Examples) FIG. 11 shows the heat absorption fins 19 of the heat radiation pipe 17.
The figure shows a coal storage silo with a structure in which the coal storage silo has a long extension and is fixed to the silo circumferential body.

Therefore, the stability of the support state of the heat dissipation pipe 17 is extremely high.

Next, in FIG. 12, the heat dissipation pipe 21 is used as a mere structural element having approximately the same length as the height of the heat absorption fin 22, and a series of cooling water pipes 23 are attached to each heat dissipation fin 22, and these are connected by hanging wires 24 to store coal. This figure shows a configuration in which the coal is suspended at a predetermined position within the silo and cooled water is forcedly circulated through the water hose 25 to cool the stored coal.

[Brief explanation of the drawing]

Figures 1A and B are explanatory diagrams briefly showing the results of spontaneous ignition simulation, Figures 2 and 3 are cross-sectional views showing embodiments of the present invention, and Figures 4 and 5 are for different heat dissipation pipes. FIG. 6 is a perspective view showing an example of the configuration, FIG. 6 is a cooling water circulation circuit diagram, FIGS. 7 and 8 are perspective views showing an embodiment of the present invention, and FIGS. A cross-sectional view and a horizontal cross-sectional view, FIG. 11 is a cross-sectional view showing an embodiment of the present invention, and FIG.
The figure is a perspective view showing the configuration of a heat dissipation pipe.

Claims (1)

[Scope of Claims] 1. In the coal storage silo, a metal heat radiation pipe with high thermal conductivity is installed in a part where the heat generation and temperature rise of the stored coal is particularly large; A length that passes vertically through the center of the central cone-shaped coal storage silo through a part where the temperature rise is particularly large, or reaches at least a part where the heat generation and temperature rise of the stored coal is particularly large from the upper end of the conical hopper-shaped coal storage silo. An insulating inner tube is arranged concentrically at the center of the outer tube, starting from near the upper end of the non-penetrating metal outer tube with high thermal conductivity, and below the outer tube. It is installed as a double-pipe structure with an opening near the bottom, and the heat generated by the stored coal,
A coal storage silo having a heat dissipation pipe, each characterized by: heat absorption fins protruding radially toward a portion where the temperature rise is particularly large.