JPH0133407B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a method for discharging coal from a coal silo, and more specifically, the present invention relates to a method for discharging coal from a coal silo in a continuous and stable state from a silo called Atlas System Coal Silo (trade name: manufactured by Atlas Corporation in the United States). This is a method of paying out.

One example of a silo that has the function of storing and discharging solid materials such as coal is the Atlas System silo. As shown in FIGS. 1 and 2, the silo consists of a silo body (shell) 1, an extraction conveyor 2,
It is composed of a delivery conveyor 3 and a sweep device (the sweep device referred to in the present invention is a general term for a sweep bucket 4, a pull ring 5, and a drive device 6), and when the pull ring 5 is rotated by the drive device 6, the sweep bucket is G4
automatically comes into contact with the stored coal 7 in the silo, scrapes up the stored coal 7, carries it to the top of the extraction conveyor 2, and drops it into the conveyor. Since a delivery conveyor 3 is installed at the tip of the extraction conveyor 2 via a hopper 8, the coal 7 on the extraction conveyor 2 is delivered to the outside of the silo through the delivery conveyor 3. The conventional control method for discharging coal from a silo having such a mechanism was based on the extraction capacity of an extraction conveyor.
That is, the loading volume of coal in the extraction conveyor case is detected, and the sweep bucket chain speed is adjusted and the sweep drive device is automatically turned on according to the detection signal.
Off control was being performed. However, in the above control method, the amount of coal to be delivered is controlled based on the loading volume in the extraction conveyor case, and therefore, the weight to be delivered varies greatly depending on the apparent specific gravity of the coal. In particular, the difference between lump coal and pulverized coal is so large that it becomes noticeable. With such control, the amount of coal extracted becomes unstable or the sweep device repeats intermittent operation in short periods, which damages the electric motor for the sweep device and adversely affects other equipment (particularly the conveyor). In addition, with this control method, the sweep device operates for a certain period of time (usually about 40 seconds) as soon as a signal indicating "low flow rate of the extraction conveyor" is issued, and after that time the sweep device stops, which is a repetitive operation. The operating time of the sweep device is arbitrarily set depending on the sweep bucket chain speed and the capacity of the multiple (usually four) extraction conveyors. However, if this setting time is too long, the amount of extraction becomes unstable as described above, such as excessive extraction. Furthermore, it has been difficult to increase the set time because it may cause overload on the delivery conveyor or the like, causing trouble. Further, when the remaining amount of coal in the silo is extremely small, the above-mentioned control causes a defect in which the extracted amount is reduced, so it is difficult to discharge coal when the amount of stored coal is small, for example, 100 T/h or less.

In addition to solving the above problems, the present inventors investigated a method for continuously and stably discharging the coal in the silo, and installed a merit detector on the dispensing conveyor (for details, refer to the Measurement Engineering Terminology Dictionary (published by Ohmsha Shoten), etc.) ) to detect the weight of coal on a dispensing conveyor and to control the dispensing of coal in accordance with the detection signal, thereby providing the present invention. That is, the present invention provides a method for extracting coal from a silo, such as the Atlas system, which has two or more extraction conveyors, a dispensing conveyor communicating therewith, and a sweep device, and a mechanism for transferring coal via the extraction conveyors to the dispensing conveyor by operation of the sweep device. When discharging coal, a merit detector is installed at at least one location on the dispensing conveyor, the detector detects the weight of coal on the dispensing conveyor, and the driving time of the sweep device is controlled and the extraction conveyor is controlled according to the detection signal. This method is characterized by controlling the number of coal silos in operation.

When discharging coal using the method of the present invention, even when the amount of stored coal is extremely small, the operation time of the sweep device can be arbitrarily increased, so coal can be disbursed without pulsation.

Furthermore, the problem of excessive extraction caused by operating the sweep device for a long period of time can be solved by controlling the number of extraction conveyors in operation in parallel.

As the conveyor for extraction and dispensing used in the present invention, any known conveyor such as a chain type or a belt type can be used without particular limitation. is common.

The method of the present invention is preferably used for the well-known Atlas system silo as described above, but what is particularly important in the control method of the present invention is that a merit detector is installed on the dispensing conveyor, and the detector detects the The purpose is to detect the coal weight and control the drive time of the sweep device and the number of operating extraction conveyors in accordance with the detection signal. In this case, the type and capacity of the merrick detector may be appropriately selected from known ones depending on the type and amount of coal to be handled, and the installation location and electrical wiring for controlling the merrick detector, extraction conveyor, and sweep device, etc. are as described above. Any conventionally known method may be used as long as it satisfies the requirements.

According to the control method of the present invention, since the amount of coal discharged is constant, coal from different types of coal from silos can be mixed on the belt conveyor, and the number of bunkers can also be reduced. It is also effective when discharging not only coal but also grain.

FIG. 3 shows a conventional control flow before the present invention. That is, conventionally, the amount of coal stored in the silo to be discharged was determined by detecting the volume of coal on the extraction conveyor by a flow rate (volume) detector 9 installed on the extraction conveyor 2, and sending the detection signal to the control device 10 to control the extraction conveyor. The sweep device 6 was controlled to be turned on and off based on the difference between the coal extraction setting value and the coal extraction setting value determined by 2. At this time, the drive time of the sweep device 6 is not controlled according to the lime volume detection signal on the extraction conveyor, and the drive time is set in advance to a constant value (usually about 40 seconds) by the control timer 11. Then, depending on the difference between the coal volume detection signal on the extraction conveyor and the coal extraction setting value, the sweep device 6 is turned on.
It was simply an OFF control.

On the other hand, in the control method of the present invention, as shown in the control flow in FIG. In other words, the control device 10'
to control the driving time of the sweep device 6, and
Extracting the control signal Conveyor operation number control device 1
It also controls the number of operating conveyors 2 and 2. In this way, by selecting both the driving time of the sweep device and the number of operating extraction conveyors as the operating variables, it is possible to control the number of operating extraction conveyors to solve the problem of excessive extraction caused by operating the sweep device for a long time as described above. This can be solved by performing these in parallel, making it possible to continuously and stably dispense coal.

In carrying out the present invention, as shown by the broken line in FIG. 4, the volume of coal on the extraction conveyor is detected by the flow rate (volume) detector 9 installed on the extraction conveyor 2, as in the conventional method. The detection signal can also be sent to the control device 10' and used as an auxiliary control input signal when controlling the drive time of the sweep device 6 in accordance with the coal weight detection signal on the delivery conveyor.

Next, FIGS. 5 and 6 show operational control conditions when coal is actually discharged based on the control flows shown in FIGS. 3 and 4. In both figures, the horizontal axis shows the coal dispensing time (minutes) and the operating time of the sweep device (minutes), and the vertical axis shows the coal dispensing amount (T/H) at that time. In operation using the conventional control flow (see Fig. 5), even when the set coal dispensing amount is 60T/H, the dispensing amount already pulsates, and the dispensing peak is large, and the operation time of the sweep device is also unsteady. amount
When I set it to 100T/H, it became uncontrollable. On the other hand, the coal dispensing control situation when operating according to the control flow of the present invention is shown in Fig. 6, and according to the method of the present invention, even at a setting of 100 T/H, there is little variation in the peak of the coal dispensing amount. Moreover, the operation of the sweep device was steady.

[Brief explanation of drawings]

Figures 1 and 2 are typical structural diagrams of the Atlas system silo, and Figure 3 is the conventional control flow diagram.
The figure shows the control flow of the present invention, Figure 5 shows the control situation when coal is dispensed based on the control flow of Figure 3, and Figure 6 shows the control situation when coal is dispensed according to the control flow of the present invention. In the figure, 1 is the silo main body,
2 is an extraction conveyor, 3 is a discharge conveyor,
4 is a sweep bucket, 5 is a pull ring, 6 is a sweep drive device, 7 is coal, 8 is a hopper, 9 is an extraction conveyor flow rate (bulk) detector, 10, 10'
1 is a control device, 11 is a control timer, 12 is a device for controlling the number of operating extraction conveyors, and 13 is a silo discharging conveyor flow rate (weight) detector.

Claims (1)

[Claims] 1. When discharging coal from a silo that has two or more extraction conveyors, a dispensing conveyor connected thereto, and a sweep device, and a mechanism for discharging coal via the extraction conveyor and transporting it by the dispensing conveyor by the operation of the sweep device, From a silo characterized by installing a merit detector, detecting the weight of coal on a delivery conveyor by the detector, and controlling the driving time of the sweep device and the number of operating extraction conveyors according to the detection signal. method of discharging coal.