JPS6140754Y2 - - Google Patents

Description

[Detailed explanation of the invention] This invention is a coke dry fire extinguishing system (hereinafter referred to as CDQ).
(hereinafter referred to as "equipment"), particularly regarding the improvement of dust combustion equipment in CDQ equipment.

Generally, red-hot coke extruded from a coke oven is cooled by wet or dry extinguishing methods.
Dry fire extinguishing in a closed system using circulating cooling gas recovers heat by operating a boiler that uses the generated high-temperature gas, and improves coke quality by suppressing the generation of fine cracks. CDQ for reasons such as improving the work environment by preventing dust generation.
The equipment has become much more popular in recent years.

The outline of the above-mentioned CDQ equipment is as shown in Figure 1.
Main body 1, high-temperature gas flow path 2 with a primary dust collector, boiler 3 with a deaerator 13 for water supply, and circulating gas flow path 4 for low-temperature gas supply with a secondary dust collector It is configured to extinguish the red hot coke in the CDQ main body 1 using circulating gas, and to continuously operate the boiler 3 using the high temperature gas generated by the heat exchange at that time.

The CDQ main body 1 has a vertical furnace shape with an upper inlet 5 for injecting red hot coke at the upper part, a large number of sloping friues 7 in the circumferential direction of the middle part, and a circulating cooling gas inlet 8 at the lower part. In the structure, the area above the level of the sloping flue 7 inside the main body forms a pre-chamber, and the area below this level forms a cooling chamber. A lower discharge device 6 for discharging the cooled coke is provided at the lowest part of the CDQ main body.

A high-temperature gas flow path 2 is provided connected to the sloping flue 7 of the CDQ main body 1, and the flow path 2 includes a dust collection plate 9 and a dust cooling pipe 10 in the middle thereof.
A primary dust collector consisting of a primary dust collector is provided and communicates with the hot gas inlet 11 of the boiler 3. The gas outlet 12 of the boiler 3 is connected to the circulating gas flow path 4
It connects to the cooling gas inlet 8 of the CDQ main body 1 through the cooling gas inlet 8, forming one closed system. In the circulating gas flow path 4, a normal cyclone 17 is disposed as a secondary dust collector, and a blower 18 for feeding circulating gas for cooling into the CDQ main body 1 is disposed.

The boiler 3 is also equipped with a deaerator 13 for water supply, and the deaerator 13 is supplied with water from a water source via a water supply pipe 15 by a water supply pump 16, and the water supply is supplied via a steam supply pipe 14. The dissolved gas is heated to near the boiling point by high-temperature steam, and then the dissolved gas is degassed and then continuously supplied to the boiler 3.

In the CDQ equipment described above, dry extinguishing of coke is performed as follows. In other words, the red hot coke pushed out of the coke oven is carried to the top of the CDQ body 1 by a coke bucket truck (not shown) pulled by a train, and the coke put in the coke bucket is lifted up by a crane and transferred to the CDQ by an on-furnace charging device. It is thrown into the internal chamber of the main body 1. Red-hot coke is charged in batches, for example once every 10 minutes, while cooled coke is discharged almost continuously at intervals of 90 seconds, for example, by the lower discharge device 6, but red-hot coke is constantly charged into the pre-chamber. must be held. This is to avoid causing too much variation in the operation of the boiler 3. The circulating gas for cooling and extinguishing the red-hot coke is an inert gas containing nitrogen as a main component, and the temperature at the inlet 8 is maintained at about 180°C. As the cooled coke is discharged, the red hot coke exchanges heat with the circulating gas while descending within the internal chamber of the CDQ main body, especially the cooling chamber.In this case, the coke temperature in the pre-chamber is approximately 1000℃.
while the discharged coke is cooled to a temperature of approximately 200°C. The gas that has undergone heat exchange with the red-hot coke becomes a high-temperature gas of about 800° C. and is extracted into the high-temperature gas passage 2 through the sloping friue 7 in the middle part of the CDQ main body 1.

Large dust contained in the high temperature gas flow is removed by a primary dust collector consisting of a dust collection plate 9 and a dust cooling pipe 10 to avoid gas cutting into the boiler and other equipment, and the high temperature gas after primary dust removal is removed. The gas enters the boiler 3 through the high-temperature gas inlet 11, where heat exchange takes place and the sensible heat contained in the circulating gas is recovered as steam in the boiler 3.

After heat exchange is performed in the boiler 3, the circulating gas is collected even fine secondary dust by a cyclone 17 disposed in the circulating gas passage 4, and is circulated again to the CDQ main body 1 by a blower 18. The collection of secondary dust by the cyclone 17 is performed by the blower 1.
This is done to prevent damage to the feathers of No. 8.

The primary and secondary dust generated during the operation of CDQ equipment is collected by a primary dust collector and a secondary dust collecting cyclone, respectively, and reused in, for example, a sintering factory, but a considerable amount of this dust is It has a high temperature and is cooled using industrial water to make it easier to handle. That is, the primary dust is cooled by passing cooling water through the water-cooled jacket 10' of the dust cooling pipe 10, and the secondary dust and circulating gas are passed through the water-cooled jacket 17' of the cyclone 17 to cool the dust.

Conventionally, in the operation of CDQ equipment, the cooling water for the generated dust is discharged outside the system without any heat recovery after heat exchange, while the boiler feed water is heated by steam in the deaerator as mentioned above. It is heated to around 105℃ and then supplied to the boiler.

In addition, Japanese Patent Application Laid-Open No. 131602/1983 discloses that red-hot lump coke discharged from a coke oven is received into a cooling tower,
After inert gas is blown into the lower part of the tower to cool the coke, air is blown into the highly heated gas discharged from the upper part of the tower in the flue to reduce the _H2 concentration in the gas, and then After guiding the gas to a coarse dust remover and removing the coke powder contained in the gas, the gas is guided to an exhaust heat boiler, where the heat contained in the gas is applied to the boiler, and then the gas discharged from the boiler is passed through a cyclone. Dry cooling of glowing lump coke using circulating gas, in which the gas after removing fine particles from the gas is blown into the cooling tower from below using a blower, and some of the gas is released into the atmosphere through a gas bleeder. A circulation method characterized in that air is blown into a coke dust accumulation bunker which is dust-removed in a coarse dust remover and deposited in the lower part of the same to burn the coke breeze, and if necessary, air is blown into the flue. A red hot lump coke dry cooling method is disclosed in which the gas composition and temperature can be freely controlled.

That is, like the conventional device, an air inlet is provided in the flue, but unlike the conventional device, the air inlet is provided near the lower end of the fine coke accumulation bunker provided at the bottom of the coarse dust remover. Therefore, in order to reduce the H ₂ concentration, that is, to convert H ₂ to H ₂ O, the amount of air blown through the air inlet is kept to the minimum necessary, and air is blown in from the air inlet to combust cheap coke breeze. By doing so, the H ₂ concentration in the circulation system can be reduced and a constant amount of steam can be advantageously obtained at all times. Furthermore, if the H ₂ concentration can be lowered to a predetermined value or less only by blowing air through the air inlet, it is possible to eliminate the need for blowing air through the air inlet.

Therefore, the large amount of air that was conventionally blown in from the air inlet to lower the H ₂ concentration can be reduced to the necessary minimum or even unnecessary, and the H ₂ concentration can be reduced without burning out expensive lump coke. can be lowered. In addition, when the amount of red-hot lump coke from the coke oven that is introduced into the cooling tower decreases temporarily, by sending air through the air inlet, it is possible to burn the coke breeze and raise the temperature of the circulating gas. This can compensate for the decrease in the amount of steam generated.

However, this method also presupposes the provision of a conventional coarse dust remover and fine coke bunker.

This invention was devised in view of the fact that the primary and secondary dust collectors account for a relatively large proportion of the equipment cost in the above-mentioned CDQ equipment. It consists of a closed system consisting of a hot gas flow path, a boiler and a circulating gas flow path for low temperature gas supply.
In a dust combustion device in a CDQ facility, an air introduction pipe for dust combustion is opened in a sloping flue section leading from the CDQ main body to a high-temperature gas flow path.

Embodiments of the present invention will be described below with reference to FIGS. 2 and 3. Each part of the CDQ equipment is given the same reference numerals as in Figure 1. In Fig. 2, the circulating gas is blown into the CDQ main body 1 from the lower inlet 8, contacts the red hot coke descending from the pre-chamber to the cooling chamber inside the main body, and cools and extinguishes it. As mentioned above, the circulating gas becomes a high-temperature gas of around 800°C through heat exchange with the red-hot coke, and passes through the sloping friues 7 provided in the circumferential direction at the middle part of the main body and the annular chamber 7' surrounding the main body 1 to a high temperature. It is sent into the gas flow path 2. As described above, this hot gas flow contains coarse and fine dust particles, of which dust particles with a particle size of 1 mm or more account for approximately 10%. Since such coarse dust exerts a gas cutting effect on the gas flow path and the tubing of the attached boiler, it is collected by the primary dust collector and discharged from the system as described above.

In the present invention, since the dust contained in the high-temperature gas flow is combustible, air is introduced into the sloping flue 7 of the CDQ main body 1, the entrained scattered dust is combusted in this part, and the combustion As a result, the amount of heat input to the boiler is increased, and as a result of the dust being gasified, the primary and secondary dust collectors can be omitted, or at least these equipment can be downsized. .

Note that unlike coal and the like, coke powder is difficult to burn because it contains almost no volatile matter. Therefore, in order to burn the coke powder, it is necessary that the coke powder be brought into contact with air (or oxygen) as efficiently as possible in a high-temperature part on the upstream side.

It has been found that the throbbing friue portion is optimal as a portion that satisfies this condition. In other words, the sloping friue is the region where the gas temperature is the highest in the circulation system, and is in the range of 800 to 900°C. Also, the gas flow velocity in the cooling tower is the superficial velocity.
The velocity of about 0.5 to 0.8 Nm/s reaches 15 to 20 m/s at the above temperature in the sloping friue section, which is a completely turbulent region, and the cross-sectional area of the gas path is rapidly reduced from the cooling tower to the sloping friue. As a result, a vortex is generated in the gas flow, and the accompanying dust is also thrown around. Therefore, if air (or O ₂ ) is introduced in this area, the turbulence of the high-temperature gas will cause good combustion and most of the dust will be completely burned, and even if the dust is a little large, it will burn within a distance of about 15 meters from the gas path to the boiler. is completed.

Therefore, since most of the dust completes its combustion at the sloping frie outlet, this combustion increases the amount of heat input to the boiler, and as the dust is gasified, the primary and secondary dust traps are The collector could be omitted, or at least the equipment could be made smaller.

As shown in Figure 3, air is introduced into the sloping flue 7 because the high-temperature gas flows in the direction of the arrow toward the boiler, and the annular chamber 7' is maintained at negative pressure, so that the air is not exposed to the outside of the CDQ body. An air inlet 22 that communicates with a part of the sloping flue 7 can be bored to allow the air to be introduced by natural suction, but if necessary, a separate blower (not shown) can be installed to force the air to pass through the header pipe 21. You can also blow it in. Note that it is sufficient to introduce an amount of air sufficient to completely burn the dust, and the amount of air is adjusted by an adjustment valve 20 disposed in front of the air introduction port 22.

As is clear from the above explanation, the present invention
According to the dust combustion equipment in CDQ equipment,
The simple structure of installing an air inlet in the sloping flue part of the CDQ body and burning the generated dust with the introduced air eliminates the need for conventional equipment such as dust collectors or cyclones, or makes it more compact. This will greatly contribute to improving the efficiency of CDQ equipment, as the heat generated from the combustion of dust can be effectively used for boiler operation.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of the CDQ equipment, FIG. 2 is a schematic sectional view of the CDQ main body implementing the present invention, and FIG. 3 is a detailed diagram of the part shown in FIG. 2. 1...CDQ body, 2...High temperature gas flow path, 3...
... Boiler, 4 ... Circulating gas flow path, 5 ... Upper inlet, 6 ... Lower discharge device, 7 ... Sloping flue, 8 ... Cooling gas inlet, 9 ... Dust collection plate, 10 ... ... Dust cooling pipe, 11 ... High temperature gas inlet, 12 ... Circulating gas outlet, 13 ... Deaerator, 14 ... Steam supply pipe, 15 ... Water supply pipe, 16
...Water pump, 17...Cyclone, 18...
Blower, 20...adjustment valve, 21...air header pipe, 22...air inlet.

Claims (1)

[Scope of utility model registration request] In CDQ equipment configured as a closed system consisting of the CDQ main body, high-temperature gas flow path, boiler, and circulating gas flow path for low-temperature gas supply, CDQ
A dust combustion device for CDQ equipment that has an air introduction pipe for dust combustion opened in the sloping flue section leading from the main body to the high-temperature gas flow path.