SU809094A1 - Device for metering control - Google Patents

Description

(54) DEVICE FOR MANAGING DOSING

one

The invention relates to process control, in particular, devices for controlling the dispensing of components into discrete devices and can be used in various sectors of the chemical, petroleum refining and other sectors of the industry.

A device for controlling dosing is known, comprising a quantity sensor, the output of which is connected to the counting input of the first meter, the dose setter, the outputs of which are connected to the inputs of series-connected meters, the outputs of which are connected to the first inputs of the comparison circuit, and the advance setting element, the output of which is connected to the second input comparison schemes. The device provides a two-stage, rough-precise control of dosing 1.

However, this device has low reliability and insufficient functionality.

Closest to the proposed device is a digital control dispenser containing counters of the measured dose, dose setter, coincidence circuits

and two AND elements co-ordinated with coarse and precise dosing devices 2.

A disadvantage of the known device is low reliability and limited functionality due to the lack of prompt detection of disruptions in the dosing process, as a result of which they require the constant attention of service personnel or additional devices for monitoring the dosing process, which limits their use in automatic process control systems.

The purpose of the invention is to increase the reliability and expand the field of application of the device.

To this end, the device containing a block of series-connected meters, the other inputs of which are connected to the output of the dose setter, the first and second triggers, the inputs of which are connected respectively to the outputs of the first and second elements And, introduced the preliminary cut-off setting device, the key, the third element And divisor frequency and pulse generator, the output of which is connected via a key to the first input of a frequency divider, with the output of the first counter connected to the first inputs of the first and second And elements and the first input of the third element and And, the output of the second counter is connected to the second input of the first element And and the input of the preliminary cutoff setter, the output of which is connected to the second input of the second element And, the outputs of the third and subsequent counters are connected respectively to the third and subsequent inputs of the first and second elements And, and the first the output of the first trigger is connected to the control input of the key, the second output of the first trigger is connected to the second input of the third element I, the counting input of the first counter to the second input of the frequency divider and the third input of the third el Yementa I.

The drawing shows a block diagram of the device.

It contains unit 1 dose unit 2 serially connected counters, unit 3 preliminary cutoff, the elements And 4-6 triggers 7 and 8, the generator 9 pulses, key 10, frequency divider 11, alarm circuit 12, button 13.

By pressing button 13, trigger 7 and 8 are triggered and after that, signals from the dispenser actuators are received from the first and second outputs of the device (not shown). The dosing process begins, during which pulses arrive at the input of the device, the number of which is proportional to the amount of material being metered. The pulses arrive at the counting input of the first counter 2, at the input of the element 6 and the first input of the frequency divider 11, each pulse returning it to the initial state. Simultaneously with the start of metering, the signal from the output of the trigger 7 opens the key 10 and the pulses produced by the generator 9 arrive at the second input of the divider 11.

The frequency of the pulses coming from the generator 9 and the division factor of the divider 11 are selected so that after a predetermined length of time after the key 10 is opened, a signal is produced at the output of the divider 11. If the period of the pulses arriving at the input of the device is less than a predetermined period of time, then the divider 11 returns to its initial state before the appearance of a signal at its output. But if the period of input pulses is more than acceptable (shutdown of the pump, filter clogging on the process line, etc.), then from the output of divider 11, the input of circuit 12 receives a signal, and the output of circuit 12 produces a light or acoustic signal to alert the staff or a signal directed to eliminate the consequences of the resulting violation, for example, the inclusion of backup equipment.

The input pulses arriving at block 2 of the counters are algebraically summed in it with the target number, the code of which is entered into counters 2 from the unit 1 of the dose before dosing. When the number of pulses less than the target number by the amount set by the pre-cutter 3 arrives in the block of counters 2, a code combination of the sum accumulated by block 2 in this block and output of the element 5 to the trigger input 8 is set at the inputs of AND 5 a signal is received, after which the coarse metering actuator is closed.

After supplying to block 2 counters the number of pulses equal to the dose setting number, it will collect the sum, the code combination of which is set at the inputs of the element 4, the signal from the output of which trigger 7 will be reset, the signal at the first output of trigger 7 disappears and dosing is stopped. Simultaneously from the second output of the trigger 7, a signal arrives at the input of the element 6. And if as a result of any violation (malfunction of the actuators, etc.) the pulses continue to flow, then after the arrival several. In the counter 2, a number will be established whose code goes to the input of the element 6 and at the time the next pulse from the output of the element 6 comes to the input of the device and the input of the element 6 and the input of the circuit 12 a signal is given. Thereafter, at the output of the circuit 12, a warning signal or a signal is generated, which activates the emergency dosing termination system.

The use of new elements in the proposed device ensures the prompt detection of disruptions in the dosing process, which adversely affect the course of the technological process, reduce the quality of the products obtained, and cause losses of raw materials and finished products.

The device allows you to control the speed of the dosing process and, while lowering it to unacceptable limits as a result of contamination of process filters, failure of the feed pump and other reasons, quickly detect this disturbance and prevent a decrease in equipment performance or a decrease in product quality that may result from violations, by notifying the attendants or automatically switching on the backup equipment, it is also possible to use the proposed roystva SAUTP in automatic mode. In addition, in the proposed device, dosing is stopped after the command is given.

The economic effect from the introduction of a single device is at least 5 thousand rubles.

Claims (2)

1. Japanese Patent No. 50-15145, class G 01 F 13/00, published 1975. 2. GDR patent number 58396, cl. 42-25 / 01, publ. 1967 (prototype)