Device for automatic control of tank filling conductive environment

 

(57) Abstract:

The inventive device includes a transformer with two secondary windings 2 and 3, the rectifier diode 4, a source of operating current, made in the form of the capacitor 5, the guard electrode 6, a current limiting resistor 7, a two-channel measuring unit 8, the two-element anti-jamming, which are used capacitors 9 and 10, twelve resistors 11 - 14, 17, 18, 23 - 25, 33 - 35, optocoupler emitter 19 and the receiver 26, the actuating relay 27, three diodes 28, 30 and 32, three transistors 20, 21 and 22, the source of the reference voltage capacitor 31, the capacitor 29. 1 Il.

The invention relates to devices for automatic control of tank filling bulk and liquid conductive materials, such as coal, rock, silo, flour, slurries, chemicals, etc., and is intended primarily for use in explosive atmospheres for mining, chemical, oil industry and in agriculture.

The purpose of the invention increase the functional reliability due to elimination of the unstable work of the Executive body.

The goal is achieved in that the device for dvukhurovnevoi, opto-block, two-channel measuring unit, a source of operating current, made in the form of a capacitor, the first plate of which is connected to the guard electrode and the second output of the second secondary winding of the transformer, the first output of which is through a rectifying diode connected to the second plate of the source of operating current, is connected through a current limiting resistor to a common bus, the electrodes of the upper and lower level, respectively connected through first and second resistors respectively to the first and fourth input channel of the measuring unit, which is also connected to the first conclusions respectively of the first and second elements and anti-jamming, second, the conclusions of which are connected respectively with the second and third input channel of the measuring unit, the first and second outputs which respectively through third and fourth resistors connected to the inputs of the opto-block, which are also connected respectively to the fifth and sixth resistors, the emitter of the optocoupler is connected in series between the seventh and eighth resistors, and the first output of the receiver optocoupler connected to the first output winding of the actuating relay and the cathode of the first diode, the anode coupled to the anode of the second diode, the cathode of which is connected to the first output of the first secondary winding of the transformer, the second output of which is connected to the second plate of the first capacitor and the second output of the receiver optocoupler, OPTRON the unit is made in the form of element AND-NOT, and the device further introduced the ninth, tenth resistors connected to the guard electrode and respectively the second and third input channel of the measuring unit, the eleventh and twelfth resistors, the second set of conclusions which are connected respectively to the first and fourth input channel of the measuring unit, the third diode and the source of reference current, made in the form of a capacitor, the first plate of which is connected to the first conclusions of the eleventh and twelfth resistors, the second output of the seventh resistor and the anode of the third diode, the cathode of which is connected to the first output of the second secondary winding of the transformer, the second winding of which is connected to the second plate of the source of reference voltage connected to the first plate of the source of operating current and the second pins of the fifth and sixth resistors, and the element AND IS NOT made in the form of a transistor switch connected to the source of reference voltage, and trigger you the control channel of the measuring unit, the second output of which is connected to the input of a transistor switch, the output of which is connected in series with the trigger output and the emitter of the optocoupler.

The invention is illustrated in the drawing.

Device for automatic control of tank filling conductive medium includes a transformer with a primary winding 1 and two secondary windings 2 and 3. The first output of the second secondary winding 3 of the transformer through the rectifier diode 4 is connected to a source of operating current, made in the form of the capacitor 5. The first capacitor plate 5 is attached to the guard electrode 6 and the second output of the second secondary winding 3 of the transformer, and a second plate connected to a rectifier diode 4 through a current limiting resistor 7 is connected to the shared bus.

The structure of the device includes a two-channel measuring unit 8 with four inputs shunted by elements of anti-jamming, which are used capacitors 9 and 10. The first outputs of the capacitors 9 and 10 are connected respectively to the first and third inputs of the block 8, and the latter conclusions respectively to the second and fourth inputs of the block 8, the second and third inputs which through the ninth and de is story 13 and 14 are connected to the electrodes 15 and 16 of the upper and lower level. The outputs of the measuring unit 8 through the third and fourth resistors 17 and 18 connected to the inputs of the opto-block.

OPTRON the block consists of the emitter 19 of the optocoupler, logic gate AND IS NOT made in the form of trigger two transistors 20 and 21 different conduction and transistor 22.

The emitter of transistor 20 is connected to the collector of the transistor 21 through the eighth resistor 23, and the input trigger is connected to the fifth resistor 24 and through the third resistor 17 connected to the first output of the measuring unit 8, the second output of which through the fourth resistor 18 is connected to the sixth resistor 25 and the input of the transistor switch 22, the output of which is connected in series with the trigger output and the emitter 19 of the optocoupler.

The first output of the receiver 26 optocoupler connected to the first output winding of the actuating relay 27 and the cathode of the first diode 28, the anode of which is connected with the second output winding of the actuating relay 27 is also connected to the first plate of the first capacitor 29 connected to the anode of the second diode 30, the cathode of which is connected to the first output of the first secondary winding 2 of the transformer, the second output of which is connected to the second plate of the first capacitor 29 and the second output of priem the first is both a reference source for the measuring unit 8. The first capacitor plate 31 is connected to the anode of the third diode 32, the cathode of which is connected to the first output of the second secondary winding of the transformer, the second terminal of this winding is connected to the second capacitor plate 31 and is connected to the first plate of the source of operating current of the capacitor 5, the second findings of the fifth and sixth resistors 24 and 25 and transistor key 22.

The first capacitor plate 31 is also connected through a seventh resistor 33 to the emitter 19 of the optocoupler and is connected with the first conclusions of the eleventh and twelfth resistors 34 and 35, the latter findings are connected respectively to the first and fourth inputs of the measuring unit 8.

As a result, the emitter 19 of the optocoupler is connected in series between the seventh and eighth resistors 33 and 23.

The device operates as follows.

With empty vessel, the current from the operational source by measuring circuits through the input unit 8 does not leak. The outputs of the measuring unit 8 signals are absent, the current through the opto unit does not leak, the Executive relay 27 is deenergized.

As the load of the tank body which is connected to a common ground bus, the lower electrode thelego unit 8 current flows through the circuit: the first capacitor plate 5, inputs 3-4 lower level control of the measuring unit 8, the resistor 14, the electrode 16, the resistance of the material filling the tank, the body of the tank 36, the common ground bus, a current limiting resistor 7, the second capacitor plate 5. When this operational current through the input of the measuring unit 8 exceeds the current from the reference source (condenser 31), which is determined by the resistance of the twelfth resistor 35. As a result, the second output of the measuring unit 8 of a signal, which brings the transistor switch 22 in a state of conduction. However, the current through the opto unit does not leak, because the trigger is performed on the transistors 20, 21, is closed, actuating relay 27 is deenergized.

Upon reaching the surface of the fill tank of the electrode material 15 of the upper level of the operational current is passed through the inputs 1-2 top level control of the measuring unit 8. The magnitude of this current is determined mainly by the resistance of the controlled material (resistance of the first resistor 13 and the limiting resistor 7, included in the circuit controlled current can be neglected, since their values on the order of magnitude or more smaller than the resistance of the controlled material), PR is datoga resistor 34. As a result, the first output of the measuring unit 8, a signal occurs, which moves the trigger 20, 21 in a state of conduction. Since transistor switch 22 at the time was in a state of conduction through the emitter 19 of the optocoupler begins to flow of current through the receiver 26 optocoupler results in actuation of the actuating relay 27.

During unloading of the tank electrode 15 of the upper level loses contact with the controllable material. The first output of the measuring unit 8 in this case, the signal is missing, but the Executive relay 27 remains in the drawn condition. This is because the trigger 20, 21 and without a control signal remains in a state of conduction, fulfilling the role of an electric latch. Executive relay 27 remains in drawn condition until such time as the supply tank is empty, i.e., cease the contact controlled material, the electrode 16 of the lower level. At the second output of the measuring unit 8, the signal becomes close to zero. Transistor switch 22 is closed, thus interrupting the circuit current is flowing through the receiver 26 of the optocoupler. Relay 27 is eliminated, indicating that the level of controllable material has reached the lower limit. The trigger 20, 21 for the functions of the logical element AND-NOT, the state of conduction of each of which corresponds to a logical "1", and the closed state of the logical "0".

The specified construction of the opto-block, along with galvanic separation of measuring and actuating circuits, provides relaynet actuation of the actuating relay 27 and eliminates the possibility of an unstable mode of its operation to the actuation setting. However, the imposition of the reference source to the capacitor 31 eliminates the influence on the device operation voltage fluctuations in the network, the ambient temperature and reducing the operational voltage source upon actuation of the actuating relay.

This is achieved by the fact that the inputs of the measuring unit 8 compares the operating current proportional to the voltage on the capacitor 5, and a reference current proportional to the voltage on the capacitor 31. The capacitors 5 and 31 are attached to the same secondary winding 3 of the transformer through a counter connected between the diodes 4 and 32. As a consequence, the voltage on the capacitor 5 is proportional to the voltage of one half-wave, and the voltage on the capacitor 31 is proportional to the voltage of the other half-wave of the same source: the measuring unit 8 is determined only by the ratio between the resistance of material inspected in the circuit of the operational source (capacitor 5) and the resistance in the circuit reference source (condenser 31) respectively of the upper and lower levels. If a sufficiently large amplification factor of the measuring unit 8, the magnitude of the output signal is virtually does not depend on fluctuations in the supply voltage or the ambient temperature and the threshold of the measuring unit depends only on the ratio of resistors in the circuit of the operational and reference currents.

Consequently, the fit of the voltage on the secondary winding 2 when firing a powerful Executive relay 27 also does not affect the input of the measuring circuit unit 8, and therefore cannot cause unstable operation of the actuating relay 27.

Thus, the invention improves the functional reliability of the device control level, to expand its range of applications to automate downloading of tanks conductive materials in hazardous environment.

DEVICE FOR AUTOMATIC CONTROL of TANK FILLING CONDUCTIVE MEDIUM containing a transformer with two secondary windings, opto-block, two-channel measuring unit, a source of operating current, made in the form of a capacitor, the first plate of which is connected to the guard electrode and the second output of the second secondary of the operational current, connected through a current limiting resistor to a common bus, the electrodes of the upper and lower level, connected via first and second resistors respectively to the first and fourth input channel of the measuring unit, which is also connected to the first conclusions respectively of the first and second elements and anti-jamming, the second set of conclusions which are connected respectively with the second and third input channel of the measuring unit, the first and second outputs which respectively through third and fourth resistors connected to the inputs of the opto-block, which are also connected respectively to the fifth and sixth resistors, the emitter of the optocoupler is connected in series between the seventh and eighth resistors, and the first output of the receiver optocoupler connected to the first output winding of the actuating relay and the cathode of the first diode, the anode of which is connected with the second output winding of the actuating relay and the first plate of the first capacitor, which is connected with the anode of the second diode, the cathode of which is connected to the first output of the first secondary winding of the transformer, the second output of which is connected to the second plate of the first capacitor and the second output of the receiver optocoupler, otlichayushiesya resistors, connected to the guard electrode and respectively the second and third input channel of the measuring unit, the eleventh and twelfth resistors, the second set of conclusions which are connected respectively to the first and fourth input channel of the measuring unit, the third diode and the source of reference current, made in the form of a capacitor, the first plate of which is connected to the first conclusions of the eleventh and twelfth resistors, the second output of the seventh resistor and the anode of the third diode, the cathode of which is connected to the first output of the second secondary winding of the transformer, the second output of which is connected to the second plate of the reference source current, connected to the first plate of the source of operating current and the second pins of the fifth and sixth resistors, and the element AND IS NOT made in the form of a transistor switch connected to the source of reference voltage, and trigger, made in the form of first and second transistors of different conductivity, the inlet of which is connected to the first output channel of the measuring unit, the second output of which is connected to the input of a transistor switch, the outputs of which are connected in series with the trigger output and the emitter of the optocoupler.

 

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