JP5397996B2 - Pulverized coal distribution and supply equipment - Google Patents

Description

  The present invention relates to a pulverized coal distribution and supply facility that distributes and supplies pulverized coal to a plurality of blast furnace tuyere when blowing pulverized coal from the blast furnace tuyere.

  In recent years, an operation method in which pulverized coal is blown from the tuyere of a blast furnace has been widely adopted (for example, Patent Document 1). Since pulverized coal has great cost advantages and good calorific value as an alternative fuel for coke, the amount of pulverized coal injected tends to increase.

  A large number, for example, 16 to 42 tuyere are arranged in the blast furnace, and pulverized coal transported from outside the system is blown from each tuyere, but the amount of pulverized coal blown from each tuyere is uniform. Otherwise, a uniform refining reaction will not occur in the blast furnace, leading to a decrease in productivity. Therefore, in pulverized coal blowing, it is an important issue to make the amount of pulverized coal blown from each tuyere uniform, and various studies and improvements have been made in the past to solve this problem. .

  One example will be described with reference to FIG. In FIG. 6, pulverized coal is pumped from the supply tank 1 to the distributor 3 via the supply pipe 2 by a gas pumping device (not shown). The distributor 3 receives the pulverized coal from the lower receiving portion 3a and discharges the pulverized coal from the distribution branch 3b on the side surface thereof. A blowing nozzle 4 is provided at the tip of the distribution branch pipe 3 b, and pulverized coal is blown from the tip of the blowing nozzle 4. The tip of the blowing nozzle 4 is located in the blower branch pipe 5a branched from the hot air annular pipe 5, and the pulverized coal together with the hot air supplied from the blower branch pipe 5a, from the tuyere 6a disposed at the lower part of the blast furnace 6 to the blast furnace 6 Be blown into.

  As described above, many, for example, 16 to 42 tuyere are arranged in the blast furnace, and the distribution branch pipe 3b, the blowing nozzle 4 and the blower branch pipe 5a are provided in the same number as the tuyere corresponding to each tuyere. That is, the distributor 3 supplies pulverized coal to the plurality of tuyere 6 of the blast furnace through the plurality of distribution branch pipes 3b.

  Here, the distribution branch pipe 3b from the distributor 3 to the blowing nozzle 4 has its length and shape depending on, for example, the layout of the equipment in which the blast furnace 6 and the distributor 3 are arranged, the installation status of surrounding related equipment, and the like. The flow rate is not constant because the (straight line / curve) is different and the pressure loss in each distribution branch pipe 3a is different.

  For this reason, in the example of FIG. 6, the powder flow rate measuring means 7 and the powder flow rate adjusting means 8 are provided in each of the plurality of distribution branch pipes 3b, and the absolute flow rate of pulverized coal in each distribution branch pipe 3b is measured by the powder flow rate measurement means 7. The value is grasped, and the pulverized coal flow rate in each distribution branch pipe 3b is adjusted by the powder flow rate adjusting means 8 to be uniform.

  As the powder flow rate measuring means 7, since it is necessary to know the absolute value of the pulverized coal flow rate, one having a high measurement accuracy has been conventionally used. As a highly accurate powder flow rate measuring means, a transmission and phase difference type microwave powder flow rate measuring device as disclosed in Patent Document 2 is known. In addition, a capacitance-type powder flow measuring device is known.

  On the other hand, as the powder flow rate adjusting means 8, in addition to a general powder flow rate adjusting valve, a distribution branch advance / retreat means as disclosed in Patent Document 3 is known. The example of FIG. 6 is an application of distribution branch advance / retreat means. This distribution branch advancement / retraction means adjusts the solid gas concentration of the distribution branch 3b by moving the end of the distribution branch 3b in the distributor 3 in the central direction and changing the suction point of the distribution branch 3b in the central direction. It adjusts the powder flow rate.

  Here, the transmission and phase difference type microwave type or electrostatic capacitance type powder flow rate measuring devices conventionally used as the powder flow rate measuring means 7 are all expensive instruments. Therefore, in the conventional pulverized coal distribution and supply equipment, as described with reference to FIG. 6, since the powder flow rate measuring means 7 is provided in all the distribution branch pipes 3b, there is a problem that the equipment cost increases. It was.

JP 2004-27265 A JP 2000-146646 A JP-A-3-26609

  The problem to be solved by the present invention is to reduce the cost while maintaining the functions of flow rate measurement and flow rate adjustment of pulverized coal in the distribution and supply facility of pulverized coal to the tuyere of the blast furnace.

The present invention relates to a pulverized coal distribution and supply facility that includes a distributor having a receiving portion that receives pulverized coal and a plurality of distribution branches, and supplies the pulverized coal to a plurality of tuyere of a blast furnace through the plurality of distribution branches. The at least one of the plurality of distribution branch pipes is provided with an absolute value measurement means for a pulverized coal flow rate serving as a reference, and the simple measurement means for detecting only the magnitude of the pulverized coal flow rate in the total number of the plurality of distribution branch pipes, A flow rate adjusting means for adjusting the flow rate of charcoal, and the measured value of the pulverized coal flow rate by the absolute value measuring means is calculated by dividing the total amount of pulverized coal supplied from the distributor by the total number of distribution branches. was such that the target value, with adjusting the pulverized coal flow rate by the flow rate adjusting means provided in the distribution branch pipe, by comparison means the measurement value detected by a simple measuring means provided on the total number of the plurality of distribution branch pipes And compare the absolute value target value measurements by the simple measurement means distributed branch pipes provided with measuring means, so that the measured value by the simple measuring means provided in each distribution branch pipe is all the same, the flow rate adjustment The pulverized coal flow rate is adjusted by means .

  In the present invention, the absolute value measuring means for measuring the reference pulverized coal flow rate is provided in at least one of the plurality of distribution branch pipes, the simple measurement means for detecting only the magnitude of the pulverized coal flow rate is provided in the total number of distribution branch pipes, By comparing the pulverized coal flow rates in the distribution branch pipes and adjusting the flow rate by the flow rate adjusting means, the pulverized coal flow rates in the respective distribution branch pipes can be adjusted to be uniform. Moreover, since the pulverized coal flow rate serving as a reference is measured by the absolute value measuring means, the absolute value of the pulverized coal flow rate in each distribution branch can be grasped and adjusted.

  As described above, according to the present invention, all the flow measurement means with high measurement accuracy can be obtained only by providing at least one distribution branch with absolute value measurement means that requires high measurement accuracy in order to grasp the absolute value of the pulverized coal flow rate. The function of flow rate measurement and flow rate adjustment of pulverized coal similar to the conventional equipment provided in the distribution branch pipe can be exhibited.

  And, it is only necessary to provide an expensive absolute value measuring means in at least one distribution branch, and then provide an inexpensive simple measuring means for detecting only the magnitude of the pulverized coal flow rate, and similarly an inexpensive comparing means. Equipment costs can be reduced.

An example of the distribution supply equipment of pulverized coal concerning the present invention is shown. An arrangement example of distribution branch pipes will be shown. An example of the flow rate adjusting means is shown. The other example of a flow volume adjustment means is shown. The example of a comparison display by a comparison means is shown. A conventional pulverized coal distribution and supply facility is shown.

  Embodiments of the present invention will be described below based on examples shown in the drawings.

  FIG. 1 shows an embodiment of a pulverized coal distribution and supply facility according to the present invention. In FIG. 1, pulverized coal is pumped from a supply tank 1 to a distributor 3 through a supply pipe 2 by a gas pumping device (not shown). The distributor 3 receives the pulverized coal from the lower receiving portion 3a and discharges the pulverized coal from the distribution branch 3b on the side surface thereof. The configuration of the distal end portion of the distribution branch pipe 3b is the same as that shown in FIG. That is, a blowing nozzle 4 is provided at the tip of the distribution branch pipe 3 b, and pulverized coal is blown from the tip of the blowing nozzle 4. The tip of the blowing nozzle 4 is located in the blower branch pipe 5a branched from the hot air annular pipe 5, and the pulverized coal together with the hot air supplied from the blower branch pipe 5a, from the tuyere 6a disposed at the lower part of the blast furnace 6 to the blast furnace 6 Be blown into.

  A large number, for example, 16 to 42 tuyere are arranged in the blast furnace, and the distribution branch pipes 3b are provided in the same number as the tuyere corresponding to each tuyere. That is, the distributor 3 supplies pulverized coal to the plurality of tuyere of the blast furnace through the plurality of distribution branch pipes 3b. As shown in FIG. 2, the distribution branch pipe 3b is provided so as to extend radially from the main body portion of the distributor 3, for example (FIG. 2 shows an example in which 16 distribution branch pipes 3b are provided).

  Referring to FIG. 1 again, at least one of the plurality of distribution branch pipes 3b is provided with a pulverized coal flow rate absolute value measuring means 9 for measuring a pulverized coal flow rate serving as a reference. Moreover, the simple measuring means 10 which can detect only the magnitude of the pulverized coal flow rate, and the flow rate adjusting means 11 for adjusting the pulverized coal flow rate are provided in the total number of the plurality of distribution branch pipes 3b. Further, a comparison means 12 for comparing the measurement values detected by the simple measurement means 10 provided in each of the plurality of distribution branch pipes 3b is provided.

  As the absolute value measuring means 9, since it is necessary to grasp the absolute value of the pulverized coal flow rate in the distribution branch pipe 3b, one having high measurement accuracy is used. Specifically, a transmission and phase difference type microwave powder flow rate measuring device or a capacitance type powder flow rate measuring device as disclosed in Patent Document 2 is suitable.

  Transmission and phase difference type microwave powder flow rate measuring device is the phase change of the microwave when the microwave is applied to the powder at two detection parts installed along the powder transfer tube. The flow rate of powder is measured based on the relationship coefficient, the flow rate of the powder, the cross-sectional area of the flow path of the powder, and the amount of phase change of the microwave. A flow rate measuring device for measuring the relationship between the weight bulk density of the powder to be measured and the phase change amount of the microwave applied to the powder, and setting the relationship coefficient It is provided.

  Capacitance-type powder flow rate measurement equipment measures the capacitance at two detectors installed along the powder transfer tube, and determines the powder density and the measurement waveform from the moving speed of the detector tube. It measures body flow.

  In addition, the installation quantity of the absolute value measuring means in the pulverized coal distribution and supply facility of the present invention may be one in any one distribution branch in the facility, but further considering the failure due to use, etc. You may install in two other distribution branches, respectively.

  On the other hand, the simple measuring means 10 only needs to be able to measure the relative pulverized coal flow rate corresponding to the reference pulverized coal flow rate measured by the absolute value measuring means 9. Since it is not necessary to accurately measure the absolute value of the pulverized coal flow rate, a simple and inexpensive powder flow rate measuring device can be used. Specifically, a Doppler microwave powder flow rate measuring device can be used.

  The Doppler-type microwave powder flow rate measurement device uses the μ-wave Doppler effect at one detection unit installed in the powder transport tube, and uses the frequency and amplitude measurement values reflected by the fluid particles to measure the powder. It measures body flow.

  FIG. 3 shows the flow rate adjusting means 11 employed in the embodiment of FIG. The flow rate adjusting means 11 includes distribution branch pipe advance / retreat means for moving the end of the distribution branch pipe 3b in the distributor 3 in the central direction. That is, the distribution branch advance / retreat means adjusts the solid gas concentration of the distribution branch 3b by moving the end of the distribution branch 3b in the distributor 3 in the central direction and changing the suction point of the distribution branch 3b in the central direction. And adjust the powder flow rate. As a mechanism for moving the end portion of the distribution branch pipe 3b back and forth in the center direction, the distribution branch pipe 3b can be expanded and contracted using a manual jack or the like.

  As the flow rate adjusting means, a general powder flow rate adjusting valve 11a can be provided as shown in FIG.

  The comparison means 12 compares the measured values detected by the simple measurement means 10 provided in each distribution branch pipe 3b with each other. In the embodiment, as shown in FIG. 5, only measured values of the pulverized coal flow rate detected by the simple measuring means 10 provided in each distribution branch pipe 3b are displayed as a radar chart for comparison. Here, the measured value A in FIG. 5 is a measured value by the simple measuring means 10 in the distribution branch pipe 3 b provided with the absolute value measuring means 9. An accurate absolute value of the pulverized coal flow rate of A is grasped by the absolute value measuring means 9, and is adjusted to a desired flow rate by the flow rate adjusting means 11 provided in the distribution branch pipe 3b. For the other distribution branch 3b, based on the comparison display result as shown in FIG. 5, the flow rate adjustment unit 11 adjusts the measurement value detected by the simple measurement unit 10 in the distribution branch 3b to the reference value A. adjust. If it does so, the pulverized coal flow rate in all the distribution branch pipes 3b will become uniform, and the absolute value will also become a desired flow rate.

That is, in the pulverized coal distribution and supply facility according to the present invention, the pulverized coal is distributed and supplied by the following steps 1 to 3.
Step 1: In the distribution branch pipe 3b provided with the absolute value measurement means 9, the flow rate adjustment means 11 provided in the distribution branch pipe 3b so that the absolute value of the pulverized coal flow rate measured by the absolute value measurement means 9 becomes a desired flow rate. To adjust the pulverized coal flow rate.
Step 2: Only the magnitude of the pulverized coal flow rate is detected and measured by the simple measuring means 10 provided in each distribution branch pipe 3b, and compared by the comparing means 12.
Step 3: Based on the comparison result by the comparison means 12, the large and small measured values by the simple measuring means 10 in the distribution branch 3b not provided with the absolute value measuring means 9 are simplified measurements in the distribution branch 3b provided with the absolute value measuring means 9. The pulverized coal flow rate is adjusted by the flow rate adjusting means 11 provided in each distribution branch pipe 3b so as to be the same as the magnitude measured by the means 10.

  In the pulverized coal distribution and supply facility according to the present invention, the pulverized coal flow rate in each of the distribution branch pipes 3b can be uniformly adjusted with an accuracy of ± 5% by performing the distribution and supply method according to the above steps 1 to 3.

DESCRIPTION OF SYMBOLS 1 Supply tank 2 Supply pipe 3 Distributor 3a Receiving part 3b Distribution branch 4 Blowing nozzle 5 Hot-air annular pipe 5a Blower branch 6 Blast furnace 6a Tuyere 7 Powder flow rate measurement means 8 Powder flow rate adjustment means 9 Absolute value measurement means 10 Simple measurement Means 11 Flow rate adjusting means (distribution branch pipe advance / retreat means)
11a Powder flow rate adjusting valve (flow rate adjusting means)
12 Comparison means

Claims (3)

In a distribution facility for pulverized coal, comprising a distributor having a receiving part for receiving pulverized coal and a plurality of distribution branches, and supplying pulverized coal to a plurality of tuyere of a blast furnace through the plurality of distribution branches,
At least one of the plurality of distribution branch pipes is provided with an absolute value measuring means for a pulverized coal flow rate serving as a reference,
A simple measuring means for detecting only the magnitude of the pulverized coal flow rate and a flow rate adjusting means for adjusting the pulverized coal flow rate are provided in the total number of the plurality of distribution branch pipes,
Provided in the distribution branch so that the measured value of the pulverized coal flow rate by the absolute value measuring means becomes a target value calculated by dividing the total amount of pulverized coal supplied from the distributor by the total number of distribution branches. In addition to adjusting the pulverized coal flow rate by the flow rate adjusting means, the measured values detected by the simple measuring means provided in the total number of the plurality of distribution branch pipes are compared by the comparison means, and the distribution branch pipe provided with the absolute value measurement means The flow rate adjustment means adjusts the pulverized coal flow rate so that the measurement values by the simple measurement means provided in each distribution branch are all the same, with the measurement value by the simple measurement means as a target value. A pulverized coal distribution and supply facility. As the absolute value measuring means, a transmission and phase difference type microwave type, or a capacitance type powder flow rate measuring device is provided,
The distribution supply equipment for pulverized coal according to claim 1, wherein a Doppler type microwave powder flow rate measuring device is provided as the simple measuring means.   The distribution supply of pulverized coal according to claim 1 or 2, wherein the flow rate adjusting means is provided with a powder flow rate adjusting valve or a distribution branch pipe advance / retreat means for moving the end of the distribution branch pipe in the center direction inside the distributor. Facility.

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