JPH11148630A - Electric dust collector ash collection method for heavy oil fired boiler - Google Patents

Abstract

[57] [Abstract] [Problem] The ash of a heavy oil fired boiler collected by an electric dust collector can be reburned in a furnace of a pulverized coal fired boiler and reused as cement raw material, etc., thereby reducing industrial waste and Provided is a method for collecting ash from an electric dust collector for a heavy oil fired boiler, which can reduce the cost. SOLUTION: Heavy oil-fired boiler ash collected by an electric dust collector 7 is injected into a furnace 1a of a pulverized coal-fired boiler through a port 10 provided near a burner 2 through the ash transfer line 9 into the furnace 1a. And make it burn again.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for collecting ash from an electric dust collector of a heavy oil fired boiler.

[0002]

2. Description of the Related Art FIG. 3 shows an example of a heavy oil fired or pulverized coal fired boiler in a thermal power plant or the like.
1 is a boiler body provided with a furnace 1a and a rear heat transfer section 1b,
2 is a burner from which main fuel such as heavy oil or pulverized coal is jetted out,
Reference numeral 3 denotes a forced air ventilator for feeding the combustion air, 4 denotes an air line for guiding the combustion air fed from the forced air vent 3 to the burner 2, 5 denotes an exhaust gas line extending from the rear heat transfer portion 1b of the boiler main body 1, 6 Is an air preheater for heating the combustion air flowing in the air line 4 with the exhaust gas flowing in the exhaust gas line 5; 7 is an electric precipitator for collecting ash contained in the exhaust gas discharged from the boiler body 1; Is a chimney.

In the boiler as described above, the combustion air heated by the pressurized ventilator 3 and passed through the air preheater 6 is heated from the burner 2 via the air line 4 to the boiler body 1.
And the main fuel such as heavy oil or pulverized coal is supplied from the burner 2 into the furnace 1a of the boiler body 1 and burns, and is generated by the combustion of the boiler body 1 in the furnace 1a. The exhaust gas thus collected is heat-recovered in a rear heat transfer section 1b provided with a superheater and a economizer (not shown) and then flows out to an exhaust gas line 5, where the air is heated by an air preheater 6 and the combustion air of the air line 4 is removed. The ash is further cooled by the heat exchange, and the ash is collected by the electric precipitator 7 and then discharged to the atmosphere from the chimney 8.

[0004] When the boiler is pulverized coal fired, the ash collected by the electric dust collector 7 can be recycled as a cement raw material or the like. However, when the boiler is heavy oil fired, the ash collected by the electric dust collector 7 is used. Is mainly composed of unburned carbon and cannot be reused as a cement raw material or the like as in a pulverized coal-fired boiler, and is currently treated as industrial waste by landfill.

[0005]

However, as mentioned above, if the ash of the heavy oil fired boiler collected by the electric dust collector 7 is treated as landfill by industrial landfill, it is necessary to secure a disposal place or to dispose of the industrial waste. There is a drawback that the processing must be entrusted to a material processing company, which leads to an increase in cost.

[0006] In view of such circumstances, the present invention allows the ash of a heavy oil fired boiler collected by an electric dust collector to be reburned in a furnace of a pulverized coal fired boiler and reused as a cement raw material, etc. An object of the present invention is to provide a method for collecting ash from an electric dust collector of a heavy oil fired boiler, which can reduce costs by reducing the amount of ash, the cost of treating ash, and the fuel cost of the pulverized coal fired boiler.

[0007]

SUMMARY OF THE INVENTION The first invention is a method for collecting ash from an electric dust collector of a heavy oil fired boiler, which is provided with an electric dust collector for collecting ash contained in exhaust gas discharged from the heavy oil fired boiler. Wherein the ash of the heavy oil fired boiler collected by the electric dust collector is charged into the furnace of the pulverized coal fired boiler and reburned, and the method is applied to the method of collecting ash from the heavy oil fired boiler. .

[0008] The second invention is an electric dust collector ash collection method for a heavy oil fired boiler provided with an electric dust collector for collecting ash contained in the exhaust gas discharged from the heavy oil fired boiler. The ash collected from the fuel oil-fired boiler from the burner of the coal-fired coal-fired boiler is put into a furnace together with the coal powder and reburned, and the method is applied to a method for collecting ash from an electric dust collector of a fuel oil-fired boiler. is there.

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

[0010] In the first invention, the ash of the heavy oil fired boiler collected by the electric dust collector is charged into the furnace of the pulverized coal fired boiler and reburned, and the ash collected by the electric dust collector in the pulverized coal fired boiler is collected. Is reused as a raw material for cement and the like.

[0011] In the second invention, the ash of the heavy oil fired boiler collected by the electric dust collector is put into a furnace together with the pulverized coal from the burner of the pulverized coal fired boiler and reburned, and the electric power in the pulverized coal fired boiler is reduced. The ash collected by the dust collector is reused as a raw material for cement and the like.

As a result, in the first invention and the second invention, it is not necessary to dispose of the ash of the heavy oil-fired boiler collected by the electric dust collector as industrial waste by landfill or the like, and it is possible to secure a disposal place. Alternatively, it is not necessary to outsource the treatment to an industrial waste disposal company, which leads to cost reduction.

[0013]

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

FIG. 1 shows an example of an embodiment of the present invention. In the figure, portions denoted by the same reference numerals as those in FIG. 3 represent the same components, and the basic configuration is the same as that of the conventional device shown in FIG. As shown in FIG. 1, the ash of the heavy oil fired boiler collected by the electric dust collector 7 is the same as that of FIG.
The point is that it is configured to be injected into the furnace 1a from a port 10 provided near the burner 2 of the furnace 1a of the pulverized coal-fired boiler via the ash transfer line 9 and reburn.

In the illustrated example, the port 10 is provided above the burner 2 of the furnace 1a of the pulverized coal-fired boiler. If the heat load is high, the port 10 is connected to the burner 2 of the furnace 1a of the pulverized coal-fired boiler. It is needless to say that it may be provided below.

In the figure, reference numeral 11 denotes a compressor for conveying the ash of the heavy oil fired boiler collected by the electric dust collector 7;
Reference numeral 2 denotes an induction ventilator provided downstream of the electric dust collector 7.

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

In the heavy oil fired boiler and the pulverized coal fired boiler, the combustion air heated by the pressurized air blower 3 and passed through the air preheater 6 is passed through the air line 4 from the burner 2 to the boiler body 1. While being introduced into the furnace 1a, the main fuel (heavy oil in a heavy oil-fired boiler, pulverized coal in a pulverized coal-fired boiler) is supplied from the burner 2 into the furnace 1a of the boiler main body 1, where combustion is performed. The exhaust gas generated by the combustion of the boiler body 1 in the furnace 1a is as follows:
Heat is recovered in the rear heat transfer section 1b provided with a superheater and a economizer (not shown) and then flows out to the exhaust gas line 5, where heat exchange with the combustion air in the air line 4 is performed by the air preheater 6. After the ash is collected by the electric precipitator 7, the ash is released to the atmosphere from the chimney 8. It is conveyed through the line 9 and is charged into the furnace 1a through a port 10 provided near the burner 2 of the furnace 1a of the pulverized coal-fired boiler.
It is reburned together with the pulverized coal escaping from the coal.

Here, the ash of the heavy oil fired boiler collected by the electric dust collector 7 has a calorific value of about 6000 kcal / kg, which is substantially equal to the calorific value of the pulverized coal. The particle size of the ash of the heavy oil fired boiler collected by the electric dust collector 7 is about 10 to 100 [μm], which is also substantially equal to the particle size of the pulverized coal. It has been actually confirmed in a basic combustion test furnace that co-firing of collected ash and pulverized coal from a heavy oil-fired boiler is possible.

The co-firing rate of the ash of the heavy oil-fired boiler collected by the electric dust collector 7 with respect to the pulverized coal is approximately 2 to 5%.
At this level of co-firing, it is possible to treat almost all of the ash from the heavy oil-fired boiler, and the ash collected by the electric dust collector 7 in the pulverized coal-fired boiler is cemented. There is no hindrance to reusing it as a raw material.

As a result, it is not necessary to dispose of the ash of the heavy oil fired boiler collected by the electric precipitator 7 as landfill, etc., and it is not necessary to secure a disposal place or to entrust the treatment to an industrial waste disposal company. It eliminates the need for waste, leading to cost reduction.

In this way, the ash of the heavy oil fired boiler collected by the electric dust collector 7 can be reburned in the furnace 1a of the pulverized coal fired boiler and reused as cement raw material, etc., thereby reducing industrial waste and cost. Can be achieved.

FIG. 2 shows another example of the embodiment of the present invention. In the figure, the portions denoted by the same reference numerals as those in FIG. 1 represent the same components, and the heavy oil collected by the electric dust collector 7 The ash of the boiler is fed into the furnace 1a together with the pulverized coal from at least one burner 2 of the pulverized coal-fired boiler via the ash transfer line 9 and reburned.

In the example shown in FIG. 2, the ash of the heavy oil-fired boiler collected by the electric dust collector 7 is conveyed through the ash conveying line 9 by the operation of the compressor 11 and is pulverized from the burner 2 of the pulverized coal-fired boiler. The ash charged into the furnace 1a together with the charcoal and reburned, and collected by the electric precipitator 7 in the pulverized coal-fired boiler is reused as a cement raw material or the like.

As a result, in the example shown in FIG.
As in the example shown in (1), there is no need to dispose of the ash of the heavy oil fired boiler collected by the electric dust collector 7 as landfill, thereby securing a disposal place or entrusting the treatment to an industrial waste disposal contractor. It eliminates the need for waste, leading to cost reduction.

Thus, in the case of the example shown in FIG. 2, as in the case of the example shown in FIG. 1, the ash of the heavy oil fired boiler collected by the electric dust collector 7 is reburned in the furnace 1a of the pulverized coal fired boiler. It can be reused as a raw material for cement and the like, which can reduce industrial waste and cost.

The method for collecting ash from an electric dust collector of a heavy oil fired boiler according to the present invention is not limited to the illustrated example described above, and various modifications can be made without departing from the gist of the present invention. Of course.

[0028]

As described above, according to the method for collecting ash from an electric dust collector of a heavy oil fired boiler according to the present invention, the ash of the heavy oil fired boiler collected by the electric dust collector is placed in the furnace of the pulverized coal fired boiler. It can be re-burned and reused as a cement raw material and the like, and an excellent effect of reducing industrial waste and reducing costs can be achieved.

[Brief description of the drawings]

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

FIG. 2 is an overall schematic configuration diagram of another example of an embodiment of the present invention.

FIG. 3 is an overall schematic configuration diagram of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Boiler main body 1a Furnace 2 Burner 7 Electric precipitator 9 Ash transport line 10 Port 11 Compressor

Claims (2)

[Claims] 1. A method for collecting ash from a heavy oil-fired boiler provided with an electric dust collector for collecting ash contained in exhaust gas discharged from a heavy oil-fired boiler, wherein the ash is collected by the electric dust collector. A method for collecting ash from an electric dust collector for a heavy oil fired boiler, wherein the ash from the heavy oil fired boiler is put into a furnace of a pulverized coal fired boiler and reburned. 2. A method for collecting ash from a heavy oil fired boiler provided with an electric dust collector for collecting ash contained in exhaust gas discharged from a heavy oil fired boiler, wherein the method is performed by an electric dust collector. A method for collecting ash from an electric dust collector for a heavy oil fired boiler, wherein the ash from the heavy oil fired boiler is put into a furnace together with the fine coal from the burner of the pulverized coal fired boiler and reburned.