JPS6036587A - Detector for break of rope to drive leveler bar of coke oven - Google Patents

Abstract

PURPOSE:To detect break of rope surely without arranging operators on the site of a coke oven, to prevent damage of devices, and to make the coke oven efficient, by detecting the primary current of a motor to drive the rope of levler bar, inputting it to a current relay. CONSTITUTION:The MC7 for shorting the secondary resistance and the resistance 2 are alternately connected in series at the secondary side of the motor 1 to drive a leveler. The MC8 for advancing the leveler and the MC9 for backing it are connected at the primary side of the motor 1, and the current transformer 3 in which the rectifier 4 and the current relay 5 are connected in series is inserted at the side of electric source. When the motor 1 is started, the primary current increases and reaches to the peak a, and changes to the load current b to operate the relay 5. When a rope to drive a leveler is broken, no load is applied, and the primary current is reduced from point c to point d, in the range B, the relay 5 is not operated, so that break of rope is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a detection device for detecting breakage of a drive rope of a propeller bar used in a coke oven.

Prior Art] Among the leveler devices employed in coke oven equipment, one is used that is configured to control movement into and out of the carbonization chamber of the coke oven using a drive rope.

In such leveler devices, there is no effective means for detecting rope breakage, and rope breakage is detected by visual judgment by an operator.

For this reason, it is necessary for workers to be constantly stationed in a harsh environment with high temperatures and lots of dust, but even so, it is necessary to judge whether the forward or reverse rope has broken, and stop the drive motor and remove the leveler from the furnace. It was difficult to take prompt actions such as evacuation. Therefore, in the past, if the rope broke, the leveler would become unusable due to heat, and the furnace would have to be shut down for a long time to repair the leveler device.

Purpose of the Invention Therefore, the present invention is capable of efficiently operating a coke oven by accurately detecting breakage of the leveler drive rope and preventing damage to the leveler bar and attached equipment without placing personnel directly at the production site. An object of the present invention is to provide a leveler bar drive rope breakage detection device for a coke oven.

Structure of the Invention The present invention provides a relay that detects the primary current of a motor that drives a leveler bar drive rope, and whose operating range is a current region under load of the motor. It is unique in that it detects a break in the drive rope by detecting a no-load current from the idle rotation.

Example DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below with reference to illustrated embodiments.

FIG. 1 shows a circuit block diagram of an embodiment of the present invention. On the secondary side of a motor 1 for driving a leveler, three MC7s for shorting the secondary resistor and three secondary resistors 2 are arranged alternately. connected in series. Furthermore, a leveler forwarding MC8 and a leveler retracting MC9 are connected to the primary side of the electric motor 1, and a current transformer 3 is inserted into the power supply side. Current relays 5 are connected in series. A circuit breaker 6 is provided on the primary side to control the supply of drive current.

The electric motor 1 is started with all three secondary resistors 2 inserted into its secondary side, and as the rotational speed increases, the resistors 2 are decreased and finally the resistors are shorted to change the load torque and the motor. When the torque is balanced, the rotational speed becomes stable at high speed.

And the primary side current is also the load current (at the stable rotation speed mentioned above)
It stabilizes at the same value, and when there is no load, the rotational speed increases until it approaches full speed (slip), but the primary current decreases.

This change in the primary side current is caused by the current transformer 3 inserted on the negative side.
After being detected by the rectifier 4 and rectified by the rectifier 4, the current is input to the current relay 5.

Figure 2 shows the characteristics of the primary current.At the time of starting, the current rises up to point a, the current under load becomes steady at point b, and when the rope breaks at point 0, the current at no load shows as d. becomes. In this characteristic diagram, the current relay 5 has an operating region in section A and a non-operating region in section B.
When the current value changes from to section B, breakage of the drive rope is detected.

Here, the current relay 5 is provided with an appropriate self-holding mechanism (not shown), and is configured so that the current relay 5 does not operate from the start of driving until the peak at point a is reached.

When the working electric motor 1 starts, the primary current increases, and after reaching the peak a at the time of starting, the load current and the constant current relay 5 are activated. Even after reaching the load rotation speed, the load current value remains within the range A, so the current relay 5 continues to maintain its operating state.

Now, when the leveler drive rope is cut, there is no load, so the primary current rapidly decreases from 0 point to the no-load current value d, and becomes region B, so the current relay 5 does not operate and the drive rope A break is detected.

It is also possible to determine whether the forward or backward rope has been cut from the direction of rotation of the motor. Lobe breakage detection is used to make an emergency stop of the connected motor. When the leveler forward rope is cut, the leveler is evacuated from the furnace body using the leveler backward rope. It is also possible to protect the leveler from heat by taking measures such as emitting a warning when the rope for retreating is cut.

Effects of the Invention The embodiment of the leveler bar drive lobe breakage detection device for a coke oven according to the present invention is as described above, and can provide the following effects.

To accurately detect a break in a leveler drive rope and prevent damage to a leveler bar and attached equipment without having to place direct personnel at the coke oven operation site, allowing the coke oven to operate efficiently.

[Brief explanation of the drawing]

FIG. 1 is a circuit block diagram showing an embodiment of the present invention, and FIG. 2 is a primary current output characteristic diagram. 1. Electric fi11, 2. Secondary resistor, 3. Current transformer, 4. Rectifier, 5. Current relay, 6. Circuit breaker,
7.Continued from page 1 of MC8 for secondary resistance short-circuit 0 Author: Takahiro Higaki Inside the Nishi-Uraga-cho, Yokosuka-shi Dosage Factory [Phase] Inventor: Fuji 1) Kenji Inside the Nishi-Uraga-cho, Yokosuka-shi, Dosage Factory

Claims (1)

[Claims] A coke oven leveler device that advances and retreats a leveler bar relative to a coke oven using a drive rope connected to an electric motor, which includes a current transformer that detects the primary current of the electric motor, and an input current transformer output. A leveler bar drive rope breakage detection device for a coke oven, comprising: a rectifier that rectifies the current, and a relay that inputs the output of the rectifier and whose operating range is the load current range of the motor.