JPH0563239B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention efficiently recovers a large amount of high-quality coal ash, which is used as a cement admixture, etc., and also carefully controls its quality. In detail, the method and device for automatically sampling coal ash generated from a coal-fired boiler, transporting it by air to an analysis building, and automatically analyzing it with an analyzer, can judge the quality of coal ash and use a classification device. The present invention relates to a coal ash quality control method and device for adjusting quality through control and determining whether the quality of coal ash for shipping is appropriate.

[Conventional technology]

Conventionally, coal ash collected by an electrostatic precipitator of a coal-fired boiler is air-conveyed to a recovery silo or a waste ash silo with or without a relay tank, and the ash in the recovery silo is led to a classification device. A commonly used ash processing method is to separate the ash into coarse powder and fine powder, with the coarse powder being charged into a coarse powder silo and the fine powder into a fine powder silo.

Currently, approximately 30% of coal ash is used as cement admixture. When analyzing the coal ash, manually operate the valve installed in the diffuser feeder section below the electrostatic precipitator, sample a small amount of coal ash, transport it by car or foot to the analysis building, and manually operate the valve. After analysis, if the quality is appropriate, the coal ash from the electrostatic precipitator is transported to a collection silo and collected.

In addition, to determine the quality of coal ash for shipping, just before shipping, a small amount is sampled from under the rotary feeder at the bottom of the collection silo or fine powder silo.
The products are transported by car or on foot to the analysis building, where they are manually analyzed to determine whether the quality is appropriate.

[Problem to be solved by the invention]

Conventional coal ash quality control methods require manual labor only during the daytime if certain conditions are met, such as when the utilization rate of coal ash is low, the power plant is small, the types of coal used are small, and the boiler load fluctuations are small. It is possible to deal with it over time. However, in modern coal-fired power plants, it has become difficult to efficiently and efficiently recover a large amount of high-quality coal ash due to larger sizes, the use of multiple types of coal, and boiler load fluctuations that occur several times a day. , it is necessary to perform quality control of coal ash continuously day and night, which is difficult with conventional methods.

The present invention was made in view of the above points, and it automatically samples coal ash generated from a coal-fired boiler between the outlet of an electrostatic precipitator and the entrance of a coal ash silo, puts it in a capsule, and transports it by air to an analysis building. By performing automatic analysis with an analyzer, we can judge whether the quality of coal ash in the electrostatic precipitator or relay tank is good or bad, adjust the quality by adjusting the classification device, and collect fine powder from the fine powder outlet of the classification device. Continuous day and night unmanned operation that can determine whether the quality of coal ash for shipping is appropriate by automatically sampling up to the silo entrance, pneumatically transporting it in a capsule to the analysis building, and automatically analyzing it with an analyzer. The purpose of this study is to provide a method for controlling the quality of coal ash.

[Means and actions to solve the problem]

In order to achieve the above object, the coal ash quality control method according to claim 1, as shown in the drawing, collects the ash collected by the electrostatic precipitators 1 and 1a of the coal-fired boiler through or without the relay tank 2. Then, the ash is conveyed by air to the collection silo 4 or the waste ash silo 3, and then
The ash is led to the classifier 7 and classified into coarse powder and fine powder.
In the ash processing method, coal ash is automatically sampled between the electrostatic precipitator 1 and 1a exits and the silo 3 and 4 entrances, and this coal ash is automatically filled into a capsule and transported by air to the analysis building 25, where it is analyzed. Automatic analysis is performed using devices 17 and 18, and based on the property analysis results, electrostatic precipitators 1 and 1a
It is characterized in that it is determined whether to send the coal ash of 1 or the coal ash of the relay tank 2 to the recovery silo 4 or to the waste ash silo 3.

In addition, the method of claim 2 is such that the ash collected by the electrostatic precipitators 1 and 1a of the coal-fired boiler is conveyed by air to the recovery silo 4 or the waste ash silo 3 via or without the relay tank 2, and recovered. In the ash processing method, the ash in the silo 4 is introduced into a classifier 7 and classified into coarse powder and fine powder, and the coarse powder is introduced into the coarse powder silo 5 and the fine powder is introduced into the fine powder silo 6. Coal ash is automatically sampled between the exit 1a and the entrance of silos 3 and 4, and this coal ash is automatically filled into a capsule and transported by air to the analysis building 25, where it is automatically analyzed using analyzers 17 and 18, and its properties are determined. Based on the analysis results, the classification operation conditions of the coal ash classification device 7 in the recovery silo 4 are adjusted to adjust the quality of the shipping coal ash.

Furthermore, the method of claim 3 pneumatically conveys the ash collected by the electrostatic precipitators 1 and 1a of the coal-fired boiler to the recovery silo 4 or the waste ash silo 3 via or without the relay tank 2, and collects the ash. In the ash processing method, the ash in the silo 4 is introduced into the classifier 7 and classified into coarse powder and fine powder, and the coarse powder is introduced into the coarse powder silo 5 and the fine powder is introduced into the fine powder silo 6. Coal ash is automatically sampled between the fine powder outlet and the fine powder silo 6 inlet, and this coal ash is automatically filled into a capsule and conveyed by air to the analysis building 25, where it is automatically analyzed in the analyzers 17 and 18, and then The feature is that it is determined from the property analysis results whether the properties of the coal ash in the fine powder silo 6 are appropriate before shipment.

The method according to claim 4 is characterized in that in the method according to claim 1, 2 or 3, the automatically sampled coal ash is temporarily stored for connection with the analyzers 17 and 18, and then automatically filled into the capsule. It is something to do.

The coal ash quality control device according to claim 5 is such that a recovery silo 4 and a waste ash silo 3 are connected to the lower part of the electrostatic precipitator 1, 1a of the coal-fired boiler via the airflow transport pipes 23, 23a. In an ash processing device in which a coarse powder silo 5 and a fine powder silo 6 are connected to the lower part of a recovery silo 4 via a classifier 7, the lower part of the electrostatic precipitator 1, 1a or the air flow transport pipe 2
3, 23a, and automatic sampling devices 8, 8 at the fine powder outlet of the classification device 7 or the fine powder silo 6 inlet.
A, 11 are connected to each other, and the automatic sampling device and analysis devices 17, 18 are connected via a sample transport tube 26.

Generally, one of the analyzers 17 and 18 is an ignition loss measuring device, and the other is a particle size distribution measuring device.

As the automatic sampling devices 8, 8a, and 11, a sampling pipe with one or more holes is inserted into a powder transport pipe, and the powder is sucked into a powder collection container through this sampling pipe. A structure with the following structure is used.

Capsule sending device 10, 10a, 13
After putting the coal ash from the temporary storage devices 9, 9a, and 12 into a cylindrical capsule, the capsule is rotated (tilted) by about 25 degrees, a screw-on lid is attached, and the capsule is turned over and heated. A known structure configured to send a capsule containing coal ash to the capsule receiving device 16 using compressed air is used. All these operations are performed automatically.
As the material of the capsule, a metal to which less coal ash adheres is used, and brass is particularly suitable.

The temporary storage devices 9, 9a, 12, 28 include:
Multiple cylindrical containers whose bottoms are opened and closed by air cylinders etc. are connected in the circumferential direction of the rotating disk, and with the bottoms of the cylindrical containers closed, coal ash is received at the receiving position of the rotating disk, and the rotating disk is rotated when discharging. A known structure is used in which the cylindrical container is brought to the discharge position and the bottom is opened using an air cylinder or the like to discharge the coal ash.

The capsule receiving device 16 receives the capsule with the lid turned up by the converting device 14b, and approximately
Rotate 25 degrees (tilt) to remove the lid, turn it over and discharge the coal ash into the bisecting device 19, and then
A known structure is used in which the capsule is inverted, closed, rotated (tilted) about 25 degrees, and sent to the capsule sending devices 10, 10a, 13 using pressurized air.

As the converting devices 14, 14a, 14b, those having a known structure are used, in which the direction of a pipe is changed by a drive device such as an air cylinder, and the pipe is connected to another pipe.

The two-splitting device 19 is a device that automatically splits the coal ash discharged from the capsule receiving device 16 into two and supplies it to the two analysis devices 17 and 18. A bisection device (JIS
M8811) to these chute,
This device is connected to a distributor that operates when the analyzer malfunctions.

Further, as the classification device 7, a dry wind type type, such as a gravity type, an inertial force type, or a centrifugal force type, is used.

Normally, as shown in FIGS. 1 and 2, temporary storage devices 9, 9a, and 12 are provided adjacent to the downstream side of automatic sampling devices 8, 8a, and 11, but if the sampling cycle is long, In this case, as shown in FIG. 3, a temporary storage device 27 is installed immediately before the analysis devices 17 and 18.

The method and apparatus of the present invention perform the following quality control.

(1) Determination of whether or not electrostatic precipitator ash can be used as a product: Air flow transport pipes 23, 23a or electrostatic precipitators 1, 1a
After automatically sampling the ash from the bottom of the ash, automatic analysis (ignition loss measurement, particle size distribution measurement) is performed.
If the ash is of good quality, it is sent to silo 4 for collection.

(2) Judging the degree of adjustment of the quality of electrostatic precipitator ash: If the average particle size of the ash automatically sampled from the air flow transport pipes 23, 23a or the lower part of the electrostatic precipitators 1, 1a is outside the appropriate value, the classification device 7 Adjust the rotation speed to obtain an appropriate average particle size.

(3) Improving the accuracy of guaranteeing product quality: After automatically sampling from the fine powder collection line of the classification device 7, automatic analysis is performed to improve the accuracy of guaranteeing product quality.

Therefore, it is possible to cope with larger coal-fired boiler power plants, the use of multiple types of coal, and boiler load fluctuations that occur several times a day, and to efficiently recover as much high-quality coal ash as possible. It is possible to provide a method for controlling the quality of coal ash. Furthermore, in the method of the present invention, a large number of samplings and analyzes can be carried out in a short period of time, so that the quality of coal ash is highly accurate and it is possible to back up the monitoring of the combustion state of the boiler.

〔Example〕

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. However, unless there is a specific description, the shapes of the components described in this example, their relative positions, etc. are not intended to limit the scope of the present invention to these, but are merely illustrative examples. Only.

Embodiment 1 FIG. 1 shows an embodiment of the coal ash quality control device of the present invention, in which a relay tank 2 is installed.

Hereinafter, an example in which the coal ash quality control method of the present invention is applied to a 700,000 kw coal-fired power plant will be explained based on FIG. 1.

As an example, from the position A (or C) of the air flow transport pipes 23, 23a from the two electrostatic precipitators 1, 1a, an automatic sampling device 8, 8a is used to collect the electrostatic precipitators 1, 1a consisting of 16 chambers. After sampling 2,000 ml of coal ash from each of two representative chambers and reducing it to 200 ml each, the excess coal ash is returned to the airflow transport pipes 23, 23a, and the coal ash for analysis is sent to temporary storage devices 9, 9a. If both the analyzer 17 (ignition loss measuring device) and the analyzer 18 (particle size distribution measuring device) can perform measurements, the temporary storage devices 9, 9a
Coal ash capsule sending device 10,10
The coal ash is put into a capsule using a device, immediately conveyed by air to the capsule receiving device 16, transferred to the bisecting device 19, and analyzed by the analyzers 17 and 18.

If the loss on ignition of the sampled ash is less than 3wt% each, the coal ash in the electrostatic precipitators 1 and 1a or the coal ash in the relay tank 2 is air conveyed to the recovery silo 4, and if the loss on ignition is 3wt% or more each. If there is, air transport it to silo 3 for disposal ash.

In addition, if the ratio of particles of 74 μm or more in the total of the two sampled ash is less than 20%, the coal ash in recovery silo 4 is used as the product, and if it is 20% or more, it is classified according to the ratio of particles of 74 μm or more. , adjust the rotation speed of the classifier 7 to reduce the proportion of particles of 74 μm or more in fine powder.
Less than 20%.

Furthermore, B (or D) of the fine powder transport pipe of the classification device 7
From the position, 200ml of coal ash is sampled with the automatic sampling device 11 and stored in the temporary storage device 12. When both the analyzers 17 and 18 can measure the coal ash, the coal ash in the temporary storage device 12 is transferred to the capsule sending device. 13 into a capsule, the coal ash is immediately conveyed by air to the capsule receiving device 16, the coal ash is transferred to the bisecting device 19, and the coal ash is transferred to the analyzer 1.
7 and 18, it is confirmed that the ignition loss of the coal ash in the fine powder silo 6 for shipping is less than 3 wt%, and the proportion of particles larger than 74 μm is less than 20%.

The above-described coal ash quality control method using continuous unmanned operation day and night makes it possible to efficiently collect as much coal ash as possible with excellent quality.

In addition, as the classification device 7, the case where a dry centrifugal type device is used is shown.

In Fig. 1, 14, 14a, 14b are conversion devices, 15, 20, 20a, 21, 22 are blowers for air flow conveyance, 24 is an air slider, 26 is a sample conveyance pipe, and 27, 27a are excess coal ash return pipes. It is.

Example 2 In this example, as shown in Fig. 2, coal ash transported by air from the electrostatic precipitators 1 and 1a is directly input into the recovery silo 4 or the waste ash silo 3 without using a relay tank. It is configured to do so.
The other configurations are the same as in the first embodiment.

Example 3 As shown in FIG. 3, in this example, in order to be applied when the sampling cycle is long, the temporary storage device 28 is installed immediately before the analysis devices 17, 18, and the automatic sampling devices 8, 8a, 11 are installed. The structure is such that a temporary storage device immediately after is omitted.
The other configurations are the same as in the first embodiment or the second embodiment.

〔Effect of the invention〕

Since the present invention is configured as described above, it has the following effects.

(1) Coal ash quality can be controlled by continuous unmanned operation day and night by determining whether the quality of coal ash is good or bad, adjusting the quality by controlling the classification device, and determining whether the quality of coal ash for shipping is appropriate.

(2) It can cope with larger coal-fired power plants, the use of multiple types of coal, and boiler load fluctuations that occur several times a day.
Coal ash of excellent quality can be recovered efficiently and as much as possible.

(3) Since a large number of samplings and analyzes can be carried out in a short period of time, the quality of coal ash is highly accurate, and it is possible to back up monitoring of the combustion status of the boiler.

[Brief explanation of the drawing]

FIG. 1 is a system flow diagram showing one embodiment of the coal ash quality control apparatus of the present invention, and FIGS. 2 and 3 are system flow diagrams showing other embodiments of the apparatus of the present invention. A, B, C, D...Coal ash sampling position,
1, 1a... Electrostatic precipitator, 2... Relay tank, 3
... Silo for discarded ash, 4... Silo for collection, 5...
...Coarse powder silo, 6... Fine powder silo, 7... Classifier, 8, 8a... Automatic sampling device, 9, 9
a... Temporary storage device, 10, 10a... Capsule sending device, 11... Automatic sampling device, 12... Temporary storage device, 13... Capsule sending device, 14, 14a, 14b... Conversion device, 15 ... Blower, 16 ... Capsule receiving device, 17 ... Analyzer (ignition loss measuring device), 18 ... Analyzer (particle size distribution measuring device), 1
9... Two dividing device, 20, 20a, 21, 22...
...Blower, 23, 23a... Air flow transport pipe, 24...
... Air slider, 25 ... Analysis building, 26 ... Sample transport pipe, 27, 27a ... Excess coal ash return pipe, 28 ... Temporary storage device.

Claims (1)

[Scope of Claims] 1. The ash collected by the electrostatic precipitators 1 and 1a of the coal-fired boiler is pneumatically conveyed to the recovery silo 4 or the waste ash silo 3 via or without the relay tank 2, and In the ash processing method, the ash of No. 4 is led to a classifier 7 to be classified into coarse powder and fine powder, and the coarse powder is introduced into a coarse powder silo 5 and the fine powder is introduced into a fine powder silo 6. Coal ash is automatically sampled from From electrostatic precipitator 1, 1a
A method for controlling quality of coal ash, which comprises determining whether to send the coal ash in the relay tank 2 to a recovery silo 4 or to a waste ash silo 3. 2 The ash collected by the electrostatic precipitators 1 and 1a of the coal-fired boiler is conveyed by air to the recovery silo 4 or the waste ash silo 3 via or without the relay tank 2, and the ash in the recovery silo 4 is transferred to a classification device. In the ash processing method in which the ash is classified into coarse powder and fine powder by introducing it into a silo 7, the coarse powder is introduced into a coarse powder silo 5, and the fine powder is introduced into a fine powder silo 6. Coal ash is automatically sampled during the process, this coal ash is automatically filled into capsules and transported by air to the analysis building 25, and automatically analyzed using analyzers 17 and 18. Based on the property analysis results, the coal ash is automatically sampled into a capsule and transported to the analysis building 25. A method for controlling the quality of coal ash, which comprises adjusting the classification operation conditions of the coal ash classification device 7 to adjust the quality of coal ash for shipping. 3 The ash collected by the electrostatic precipitators 1 and 1a of the coal-fired boiler is air-transferred to the recovery silo 4 or the waste ash silo 3 via or without the relay tank 2, and the ash in the recovery silo 4 is transferred to a classification device. In the ash processing method, the coarse powder is introduced into a coarse powder silo 5 and the fine powder is introduced into a fine powder silo 6. Coal ash is automatically sampled up to the entrance, and this coal ash is automatically filled into capsules and conveyed by air to the analysis building 25, where it is automatically analyzed by analyzers 17 and 18, and based on the property analysis results, the fine powder silo is 6. A coal ash quality control method characterized by determining whether the properties of the coal ash are appropriate before shipment. 4 The automatically sampled coal ash is analyzed by analyzer 1.
Claim 1, characterized in that the capsule is automatically filled after being temporarily stored for connection with the capsule.
Coal ash quality control method according to 2 or 3. 5 A collection silo 4 and a waste ash silo 3 are connected to the lower part of the electric dust collectors 1 and 1a of the coal-fired boiler via air flow transport pipes 23 and 23a, and a classifier 7 is connected to the lower part of the collection silo 4. In the ash processing equipment in which a coarse powder silo 5 and a fine powder silo 6 are connected,
3, 23a, and automatic sampling devices 8, 8 at the fine powder outlet of the classification device 7 or the fine powder silo 6 inlet.
A, 11 are connected to each other, and the automatic sampling device and analysis devices 17, 18 are connected via a sample conveying pipe 26.