SU756367A1 - Loose material level regulator - Google Patents

Description

one

The device refers to the automation to is designed to automatically control mainly the level of various bulk media in tanks.

Known level control flow of solids, containing two sensors, made in the form of two-phase electric motors with brake vanes on the shafts, in which the braking torque through a mechanical transmission affects microswitches [1].

However, this level control is unreliable in operation due to the large number of contacts of microswitches, springs, and other elements included in its design, as well as the need to use two electromechanical level switches.

The closest in technical essence to the invention is a level control of bulk media containing two flag sensors, microswitch contacts of which are included in the power supply circuit of the actuators 12].

However, this regulator is characterized by low reliability of operation due to low

The reliability of the low level sensor, which can be mechanically damaged by a large layer of the product, limited power and the number of trips of the microswitches connected to the inductive load circuit.

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

This goal is achieved by the fact that two power thyristors, connected in series with the executive relay, HC-circuit and dynistor are entered into the device, and the contacts of the executive relay and HC-circuit are connected in parallel to the first power thyristor, the connection point of which is connected to its resistor the control electrode, and in parallel to the control electrode-cathode of the second power thyristor, a contact level sensor is connected, as well as the fact that sequentially connected sources are inserted into it to DC and additional thyristor, connected in parallel with the transition control electrode of the second power thyristor.

756367

The drawing shows a diagram of the level control of bulk materials.

The regulator contains an executive relay 1, the winding of which through the first power thyristor 2, shunted by contacts 3 of relay 1, and the second power thyristor 4 is connected to the * AC network (terminals 5, 6); a transformer 7, the secondary winding of which through a rectifying bridge 8, a resistor 9 and an additional thyristor 10 are connected to the junction of the control electrode-cathode of the second power thyristor 4. The electrical contacts of the level sensor 11 are connected to the same junction. In parallel with the first power thyristor 2, a time-dependent AC circuit 13, 14, 15 is connected via diode 12, the capacitor 15 of which is connected to the control electrode of the first power thyristor 2 through a resistor 16 and a distor 17 and 20. The container 1 which is controlled by the level of particulate material is set an upper limit level sensor comprising electrical contacts 11. as the contacts can be used _{on may 2} mercury contacts, contacts mikroperekl ents hermetic contact or magnetically operated, mounted on the pendulum, or other membrane-type level sensor. The product is fed into the tank by a loading conveyor, gate or gate, the operation of which is controlled by the contacts (not shown) of the executive relay 1. As the executive relay I, the magnetic starter, contactor, etc. can be directly switched on. or parallel to the winding of the executive relay, the traction solenoid of the gate valve and other loads can be switched on.

The level control works as follows.

The regulator is turned on with the button 20. Through the resistors 21 and 9 and the transition control electrode-cathode of the thyristor 10 a current pulse flows, causing the thyristor to open. When the product level _{in the} tank drops below the level sensor, its contacts 11 open. The transition control electrode-cathode of the second power thyristor is desunched and under the action of the voltage of the secondary winding of the transformer 7, rectified by the bridge 8 and the filter capacitor 22, it is unlocked. Through the second open power thyristor 4 resistors 13,

14, 16, diode 12 and the winding of the relay 1 begins to flow a charge current of the capacitor 15. When the voltage on the capacitor 15 reaches the firing threshold of the dynistor 17, the latter passes through itself and the resistor 16 to the transistor

the control electrode – cathode stroke of the first power thyristor is the discharge current of capacitor 15. The first power thyristor 2 at the time of discharge of the capacitor 15 opens, and relay 1 is turned on through open power thyristors 2 and 4. Thus, although the product level is below the level sensor and its contacts 11 are open, the relay 1 and, therefore, the loading conveyors are turned on only after a certain delay specified by the HC circuit 13, 14, 15. The product begins to enter the container. As soon as the material reaches the level sensor and under the action of product pressure, the contacts 11 even briefly close, the second power thyristor 4 closes and the relay 1 turns off, opening its contacts 3. The product stops flowing into the tank. In the future, the operation of the regulator is repeated. The regulator is turned off with the button 19.

Thus, the proposed regulator provides regulation of the level of bulk media, dramatically reducing the number of actuations of the executive relay and transporting mechanisms. The regulator circuit is characterized by simplicity and high reliability in operation. When used in the proposed scheme as contacts of the reed switch level sensor, a high number of switchings 10Ϊ0 is provided, which significantly exceeds the number of switchings of the executive relays. In combination with pressure sensors, temperature, etc. The proposed controller will be used to stabilize pressure, temperature, and other quantities.

Claims (2)

Claim 1. Bulk material level controller, containing a contact level sensor and an executive relay, characterized in that, in order to increase the reliability of the device, two power thyristors, connected in series with the executive relay, an BC circuit and a threshold dynistor, are inserted into it, and parallel to the first power thyristor contacts of the executive relay and the AC circuit, the connection point of the resistor are connected and the capacitor of which is connected to its control electrode through a threshold dynistor, and a contact level sensor is connected parallel to the control electrode-cathode of the second power thyristor. 2. The regulator according to claim 1, is distinguished by the fact that, in order to simplify the circuit, a series-connected direct current source and an additional 5 756367 a thyristor connected in parallel with the transition control electrode-cathode of the second power thyristor.