SU765510A1 - Remote control for local ventilation mine fan - Google Patents

Description

I

The invention relates to the mining industry, in particular, to devices for automatic continuous monitoring of the amount of air coming to the bottom of a dead-end mine ventilated by local ventilation fans (VMP) in gas and dust hazardous mines and for the protective disconnection of electricity when the normal ventilation conditions are broken .

A remote control device is known with the use of pitch fans, which contains an air speed control sensor, a communication line, a signal receiver, an automatic reclosing unit and a starting relay 1.

This device, which performs the function of automatically degassing the ventilated generation of pulses to turn on and off VMP, does not allow for the operational stop of the VMP from the remote control panel, since the Start Equipment button is bridged by starting relay contacts, which after the pulse start remains in the on state, and therefore VMP in this

case loses controllability. This reduces the reliability and safety of work.

It is also known a remote control device with a local ventilation fan, comprising an air velocity control sensor, a communication line, a signal receiver, a time master unit, an automatic restart unit with an RC master circuit, a transistor multivibrator and a transistor switch with a starting relay, a source power supply, including a rectifying bridge, a smoothing filter, a DC amplifier and a regulating transistor, an actuator contact block, resistors, capacitors, diodes and zener diodes 2.

The automatic re-switch-on unit VMP, which is included in the remote control device of the local ventilation shaft fans, allows automatic impulse starting of the AMF during a short disconnection of the supply voltage 20 and its subsequent restoration within 1-1.5 minutes. If the supply voltage recovers in a time longer than 1 -1.5 min, the automatic re-activation of the VMP does not

will happen. The subsequent start-up of the PMP must be carried out manually using the "Start and Stop" buttons after checking the methane concentration in the dead-end mine. Otherwise, dead ends and nearby mines are gassed, which can lead to an explosion and fire hazard and endanger people’s lives.

A disadvantage of the known device is also the need for the initial manual start of the high-voltage automatic device, which, if the staff is unskilled, can cause either a delayed start of the high-voltage direct switch or the start of the small-wave guide for continuous operation when the ventilation pipe is not full, which in turn can lead to its rupture. due to the dynamic effect of the air jet.

In addition, if a short-term shutdown and supply voltage is applied, the HFM can turn on without a command, which creates the possibility of injury to the maintenance personnel during repair and expansion of the ventilation pipes.

The purpose of the invention is to increase the reliability and safety of the device.

This is achieved due to the fact that the device is equipped with a switching unit on two transistors, two additional times specifying RC circuits, an additional transistor and a capacitor, and the output of the first additional time specifies an RC circuit connected through the starting contact of the actuator to the power source the resistor is connected to the base of the additional transistor, the collector of which is connected via an additional capacitor to the input of the transistor switch, and the output of the second additional time specifies the HC circuit connected to you a direct bridge connected via a resistor and a zener diode with the base of the first transistor of the switching unit, the collector of which is connected to the base of the second transistor through another zener diode, the emitter-collector junction of which bypasses the input of the DC amplifier

The drawing is a schematic diagram of the remote control device of the mine VMP.

The device consists of an air speed sensor 1, a communication line 2 and an executive unit 3, which contains a signal receiver 4, a time master unit 5 for controlling a group device supplying current collectors of a dead-end output stabilized by the power source 6 of the automatic reclosing unit 7, node 8 of automatic start, switching unit 9, performing a fast discharge of capacitor 10. Block 7 of automatic reclosing is made on the basis of a self-oscillating multivibrator on a transistor 11, 12 to the output switch 13, which specifies the duration and off-states VMP and transistor switch, and the transistors 14, 15

with the bridge time specifying the RC circuit 16, 17, 18, 19, 20, 21 with the starting relay 22, which specifies the number of cycles when the pulse starts VMP.

The automatic start node 8 contains the time specifying the RC circuit 23, 24 fed through the auxiliary contact 25 of the actuator from the stabilized power source 6, the transistor 26, the collector of which is connected to the base of the transistor 15 through a capacitor 10. The switching unit 9 contains an RC driver circuit 27, 28 fed from a rectifying bridge 29, two transistors 30 and 31. The collector is connected via a Zener diode to the input of a DC amplifier 32 of a stabilized power source 6.

The button "Start 33", which serves for the initial start-up of the HFM, is connected in parallel with the transistor 14 of the automatic switching-on unit 7.

The power supply 6 contains a rectifying bridge 29, a smoothing filter 34, and a compensating type voltage regulator including a DC amplifier 32 and a control transistor 35. The resistor 36 is connected parallel to the filter 34 to discharge the capacitor during the removal of the supply voltage.

Operation of the device begins with the start of the HFM by briefly pressing the Start 33 button. When this happens, transistor 14 is short-circuited and capacitor 19 starts charging along the circuit: "plus power supply - button 33 - resistor 17 - capacitor 19 - emitter junction of transistor 15 -". minus power source. With the charge current of the capacitor 19, the transistor 15 opens, turns on the relay 22, which turns on the VMP starter. The collector current of the transistor 15 opens the transistor 14. Since the transistor 14 is open, the charge of the capacitor 19 continues after the button 33 is released and its contact is opened.

Simultaneously with the opening of the transistor 15, a supply voltage is applied to the multivibrator. The output relay 13, connected to the collector circuit of the transistor 11 of the multivibrator, alternately closes and opens its contact, included in the control circuit of the VMP starter, with the switching frequency of the multivibrator. The multivibrator works as long as transistors 14 and 15 are open. After charging the capacitor 19 to the voltage set by divider 16, 20, the diode 18 is unlocked and this charge stops. Transistors 14 and 15 are locked, and capacitor 19 is discharged through diode 18, resistor 20 and diode 21. At the time of locking transistor 15, transistor 11 is also locked, causing the relay 13 to turn off, and the VMP starter remains in the on state. Thus, the launch of the VMP continues after the release of the Start 33 button.

After starting the HFMP and establishing the normal mode of airing the dead-end production, the air velocity control sensor 1 outputs to the communication line 2 a signal that is fed to the signal receiver. In the receiver 4, the output relay operates, acting on the time of the master unit 5, which begins to work out the time delay of 5, 10, 15, 20 minutes (depending on the setpoint). After working off the time delay, the output relay is activated, which includes a group device, supplying dead-end current collectors (not shown in the drawing). If the dead-end ventilation is violated, the signal from sensor 1 is stopped, which causes the output relay to turn off the time of driver unit 5 and, accordingly, to disconnect the group device.

The automatic start node 8 provides automatic re-impulse switching on of the HFM during the restoration of the supply voltage for 1-1.5 minutes. Information on the operation of the HFM enters unit 8 from the HFM actuator through block 25. When HFM is operating, the block-contact 25 of the starter is closed, the capacitor 23 is charged almost to the power supply voltage. After disconnecting the supply voltage, the capacitor 23 is discharged through the emitter junction of transistor 26 and keeps it open for some time (1-1.5 min). If the mains voltage recovers during the time when transistor 26 is open, at the moment power supply voltage is applied, capacitor 10 begins to charge along the circuit: "plus power source - emitter collector of transistor 26 - capacitor 10 - emitter junction of transistor 15 -" minus source nutrition

With the charge current of the capacitor 10, the transistor 15 is opened, and consequently, the transistors 14 and 11 are also opened. The capacitor 19 is charged, keeping the charge current in the open state of the transistor 15 and thus, in this case, an automatic pulse start VMP. If the voltage in the network is at Vits after 1-1.5 minutes, then the capacitor 23 will have time to discharge to a voltage lower than the threshold level, and the transistor 26 will close. After supplying the supply voltage, the charge circuit of the capacitor 10 will be open and the automatic start of the HFMP will not occur. The HFMP can only be started by pressing the Start 33 button. The discharge time of the capacitor 23 to the threshold level is determined by adjusting the resistance value of the resistor 24.

The automatic re-activation of the HFM during short-term (up to 1 s) deep decrease or disconnection of the supply voltage with its subsequent restoration is ensured by the fact that the capacitor 27, charged before the voltage of the rectifying bridge 29, discharges relatively quickly when the power supply is disconnected through the emitter junction of the transistor 30 and keeps it open for some time. After the capacitor 27 is discharged, the transistor 30 closes, opens the transistor 31, and shunts the base circuit of the DC amplifier 32, locking it. The control transistor 35 also closes. At the output of the power supply, the voltage decreases to a few volts. The filter capacitor 34 is then discharged through a resistor 36.

When the supply voltage is restored, the capacitor 27 is quickly charged, the transistor 30 opens, the transistor 31 closes, and the normal voltage is restored at the output of the power supply. The resistor 28 is used to select the time of discharge of the capacitor 27 to the threshold level.

In this case, during short-term (up to 1 s) deep decreases or disconnections of the supply voltage, the capacitor 10 is discharged, but when the supply voltage is restored, the VMP is automatically switched on again.

Claims (2)

1. Kilman A. Sh. Et al. Improving the safety and efficiency of airing dead-end workings, M., “Coal, 1974, No. 6, p. 69-70. 2. USSR author's certificate number 648740. class. E 21 F 1/00, 12.24.75.