JP2002213718A - Combination coal/paper sludge boiler equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide combination coal/paper sludge boiler equipment capable of re-utilizing paper sludge, being industrial waste, as energy with high efficiency through minimum equipment investigation by effectively utilizing existing coal boiler equipment and attributing to saving of a consumption amount of coal. SOLUTION: Coal burning boiler equipment provided with a ball mill 2 formed that a number of balls are charged in a rotationally driven drum coal is pulverized as the coal is dried to produce pulverized coal comprises a sludge banker 8 in which paper sludge is stored; and a sludge picking device 9 to effect picking of paper sludge stored in the sludge banker 8 and feed it to the ball mill 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a coal / paper sludge co-firing boiler facility.

[0002]

2. Description of the Related Art Generally, paper sludge generated in a refining process in a papermaking company has a low calorific value, is difficult to burn alone, and requires special consideration for combustion in a furnace.
Such paper has a high moisture content (approximately 60-70 [%]), and it is difficult to transfer paper sludge, which is a fibrous mass, to pulverize it into a combustible shape. In order to reuse sludge as energy rather than simply incinerating it, conventionally, a fluidized bed boiler that burns fuel while stirring it in a furnace with a high-temperature bed material or a special boiler using a stoker incinerator Was indispensable.

[0003] As another conventional technique, there is an example in which paper sludge is mixed with coal in a coal-fired boiler. In this case, the paper sludge is dried by a fluidized-bed dryer and then crushed to form a coal. It is supplied to the burner of the boiler and burned.

[0004]

However, as described above, the installation of a new special boiler using a fluidized bed boiler increases the initial capital investment, while the fluidized bed boiler generates only low-pressure steam. It could not be said that paper sludge, which is industrial waste, was efficiently reused as energy.

[0005] In addition, if the paper sludge is dried by a fluidized bed dryer and then crushed and supplied to the burner of a coal-fired boiler to be burned, the efficiency is improved, but a fluidized bed dryer is separately provided. It has to be provided, which also has the disadvantage of leading to an increase in capital investment.

The present invention has been made in view of the above circumstances and makes it possible to efficiently reuse paper sludge as industrial waste as energy with a minimum capital investment by effectively utilizing existing coal-fired boiler equipment. The purpose of the present invention is to provide a coal / paper sludge co-firing boiler facility that can also contribute to the reduction of consumption of coal.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a coal-fired boiler facility equipped with a ball mill for loading a number of balls into a rotating drum and pulverizing coal into fine coal while drying the coal. A coal / paper sludge co-firing boiler, which is additionally equipped with a sludge bunker in which paper sludge is stored, and a sludge cutting device for cutting out paper sludge stored in the sludge bunker and supplying the sludge to a ball mill. Things.

[0008] In the coal / paper sludge co-firing boiler facility, the shape of the sludge bunker may be divergent, and a screw conveyor may be used as a sludge cutting device.

According to the above means, the following effects can be obtained.

During operation of the coal / paper sludge co-firing boiler facility, coal is introduced into a ball mill, and paper sludge stored in a sludge bunker is cut out by a sludge cutout device and supplied to a ball mill, whereby the ball mill is driven to rotate. The coal and paper sludge inside the drum are dried and pulverized by a pulverizing action such as ball impact and friction, and the pulverized coal and the pulverized paper sludge are supplied to the coal-fired boiler. Then, the pulverized coal and the pulverized paper sludge are burned.

[0011] Here, it is difficult to make the paper sludge finer only by supplying only the paper sludge to the ball mill alone. However, when the paper sludge is supplied to the ball mill together with the coal, the hard coal is produced by the stirring force of the ball. A strong shearing force is applied to the paper sludge while mixing, so that the paper sludge can be finely pulverized while being dried, and further, there is no fear that the paper sludge is deposited or clogged in the ball mill.

Also, it is true that the calorific value of paper sludge is low and it is not easy to burn as compared with coal. However, if fine paper sludge is supplied while feeding pulverized coal to a coal-fired boiler, The charcoal first burns, and the heat evaporates the moisture remaining in the paper sludge, while the paper sludge itself easily burns.

As a result, it is not necessary to newly install a special boiler using a fluidized-bed boiler or to separately provide a fluidized-bed dryer as in the prior art, and a sludge bunker and a sludge cutting machine are installed in the existing coal-fired boiler facility. Only additional equipment is needed, minimizing initial capital investment,
Paper sludge, which is industrial waste, can be efficiently reused as energy, and the consumption of coal can be reduced.

In the above-mentioned coal / paper sludge co-firing boiler facility, if the shape of the sludge bunker is made to be a divergent shape and a screw conveyor is used as a sludge cutting device, it has a high moisture content and a fibrous mass. Can be stably transferred to the ball mill without causing clogging or the like at the outlet of the sludge bunker.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, in which 1 is a coal-fired boiler, and 2 is a drum driven by rotation, in which a number of balls are loaded to pulverize the coal into pulverized coal. The ball mill 3 is a coal bunker in which coal is stored, 4 is a coal feeder for cutting out the coal stored in the coal bunker 3, and 5 is a coal mill cut by the coal feeder 4 is introduced into the ball mill 2 and finely divided by the ball mill 2. A coarse powder separator for separating pulverized pulverized coal from coarse powder and leading it to the coal-fired boiler 1, and an air preheater 6 for recovering heat of exhaust gas discharged from the coal-fired boiler 1 and preheating air. Bowl, 7
Is a chimney for discharging exhaust gas discharged from the coal-fired boiler 1 and passing through the air preheater 6 to the atmosphere. The existing coal-fired boiler facility thus configured has a chimney and a sludge bunker 8 in which paper sludge is stored. , The sludge bunker 8
And a sludge cut-out device 9 for cutting out the paper sludge stored in the tank mill and supplying the sludge to the ball mill 2 to provide a coal / paper sludge co-firing boiler facility.

In the illustrated example, the sludge bunker 8 has a divergent shape and a sludge cutting device 9.
Is a screw conveyor.

Next, the operation of the illustrated example will be described.

During operation of the coal / paper sludge co-firing boiler facility as shown in FIG. 1, the required temperature is controlled by appropriately mixing hot air passing through the air preheater 6 and cold air bypassing the air preheater 6. The ball mill primary air is introduced into the ball mill 2 through the coarse powder separator 5. In this state, the coal stored in the coal bunker 3 is cut out by the coal feeder 4, and the ball mill 2 is discharged through the coarse powder separator 5. And the paper sludge stored in the sludge bunker 8 is cut out by the sludge cutting device 9 and supplied to the ball mill 2 through the coarse powder separator 5. The paper sludge is dried by the primary air of the ball mill, and is finely crushed by crushing action such as ball impact and friction. Pulverized coal and finely divided paper sludge, which have been crushed and separated by the coarse powder separator 5 and supplied to the coal-fired boiler 1 together with the ball mill primary air, are supplied to a burner (not shown) of the coal-fired boiler 1. In the furnace, the secondary air for combustion preheated through the air preheater 6 is mixed with the pulverized coal and the finely divided paper sludge to perform combustion, and steam is generated by the combustion heat. The exhaust gas discharged from the coal-fired boiler 1 is denitrified by a denitration device (not shown) and heat-exchanged with air supplied to the coal-fired boiler 1 in an air preheater 6, and then the desulfurization device (not shown) In addition, desulfurization processing and dust collection processing are performed in the dust collection device, and the dust is discharged from the chimney 7 to the atmosphere.

Here, the sludge bunker 8 is formed in a divergent shape and a screw conveyor is used as the sludge cutting device 9, so that the paper having a high moisture content and a fibrous mass is obtained. Sludge can be stably transferred to the ball mill 2 without causing clogging or the like at the outlet of the sludge bunker 8.

It is difficult to make the paper sludge finer only by supplying only the paper sludge to the ball mill 2 alone. However, when the paper sludge is supplied to the ball mill 2 together with the coal, the hard coal is stirred by the stirring force of the ball. A strong shearing force is applied to the paper sludge while mixing the paper sludge, and the paper sludge can be pulverized while being dried. In addition, ball mill 2
Experiments have confirmed that there is no risk of paper sludge accumulating or clogging inside.

Further, it is certain that the calorific value of the paper sludge is low and it is not easy to burn as compared with the coal. However, when the pulverized coal is fed to the coal-fired boiler 1 and the finely-divided paper sludge is supplied. The pulverized coal first burns, and the heat evaporates the moisture remaining in the paper sludge, and the paper sludge itself easily burns. The co-firing ratio of paper sludge to coal can be about 5 to 20% by weight, and in an experiment in which the state was changed from the coal-fired state to the coal-paper sludge co-firing state, a ball mill 2 was used.
It has been confirmed that there is almost no change in the outlet air temperature and the generator output, and stable operation can be continued.

As a result, it is not necessary to newly install a special boiler using a fluidized-bed boiler or to separately provide a fluidized-bed dryer as in the prior art. Only additional cutting equipment 9 is required, minimizing initial capital investment, and also enabling efficient reuse of industrial waste paper sludge as energy, saving coal consumption. It is also possible to do.

In this manner, paper sludge, which is industrial waste, can be efficiently reused as energy with a minimum capital investment by effectively utilizing the existing coal-fired boiler equipment, thereby contributing to a reduction in coal consumption. obtain.

It should be noted that the coal / paper sludge co-firing boiler equipment of the present invention is not limited to the above-described illustrated example, and various changes can be made without departing from the scope of the present invention. .

[0026]

As described above, according to the coal / paper sludge co-firing boiler equipment of the present invention, paper sludge, which is industrial waste, can be used with minimal capital investment by effectively utilizing the existing coal-fired boiler equipment. An excellent effect of being able to efficiently reuse as energy and contributing to saving of coal consumption can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an example of an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Coal-fired boiler 2 Ball mill 8 Sludge bunker 9 Sludge extraction device

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F23C 1/10 F23C 1/10 F23G 5/08 ZAB F23G 5/08 ZAB (72) Inventor Jin Fukushima Tokyo 3-2-16-1 Toyosu, Koto-ku Ishikawajima Harima Heavy Industries, Ltd. Tokyo Engineering Center F term (reference) 3K065 AA23 AB01 AC02 CA02 CA12 DA01 DA04 3K091 AA20 BB02 BB25 CC13 CC17 CC23 4D059 AA30 BB01 BB14 BB18 BK11 CA10 CB06 CB06

Claims (2)

[Claims] A sludge in which paper sludge is stored in a coal-fired boiler facility equipped with a ball mill for drying a coal and pulverizing the coal into pulverized coal while loading a large number of balls inside a rotary-driven drum. A coal / paper sludge co-firing boiler facility further comprising a bunker and a sludge cutting device for cutting out paper sludge stored in the sludge bunker and supplying the sludge to a ball mill. 2. The coal / paper sludge co-firing boiler facility according to claim 1, wherein the sludge bunker has a divergent shape and a screw conveyor is used as a sludge cutting device.