SU564541A1 - Device for controlling discrete weight proportioning process - Google Patents

Description

(54) DEVICE FOR CONTROLLING THE PROCESS OF DISCRETE WEIGHT DOSING.

vani connected with the input of the block from the executive bodies and through the block 7 of the time delay - with the input of the block for determining the magnitude of the lead time; a memory unit 8 of the lead time, connected to the output of the lead determination unit 3 and the inputs of the G5 block 5 and block 4; metering control unit 9, the input of which is connected to the output of unit 4, and the output through unit 1 of selection of feeders to the input of unit 6 of the executive bodies and through distributor 11 to the inputs of unit 1 for measuring weight.

The device works as follows.

The input of block 5 simultaneously arrives from block 2. set the weight of the portion of the value of the weight of the portion of material dispensed in this cycle and from block 1 of the weight meter the value of the weight of the material supplied by the time of measurement. Block 5 determines the moment of interruption from the expression

РЗ

where PJ is the weight of the material being metered, at which the feed is interrupted;

PJ is the specified portion weight; PJ is the maximum for a given technological equipment the value of the weight of the material that is filled up after turning off the feed; K is the coefficient ensuring the supply of the material missing to the full dose in the lowest one. The practical coefficient / K is chosen in the range from 2 to 4, since the remaining part of the dose (3-6%) will be supplied after the termination of the interruption partially during the exit to the butcheral mode in time ; work in nominal mode and, finally, in the form of a material column dispenser in the receiving device after stopping the supply. When condition (1) is fulfilled, the dosing interrupter block 5 outputs a signal to the block b to interrupt the material supply and to the block 3 for determining the lead time through the block 7 of the time delay to calculate the lead time. The unit 7 delays the determination of the amount of advance by a time sufficient to complete the transients in the supply and measurement path. The time delay is 0.5-1% of the total dosing time of the portion.

 After completion of the transient processes in the supply path, the advance amount determination unit 3 determines the actual dosing error made when the material is picked up by weight, taken as the lead value from the expression

-t-i-Ti -bj.-t) / jiU (2)

P4 P9-Pl 2

where P is the lead time for the dosing cycle being performed; If is the value of the weight of the material being metered, which arrived from block 3 by the time the lead value was determined.

The memory unit 8 of the lead time memorizes, for the cycle time found from expression (2), the actual value of the lead time for the dosing cycle Pv being performed, and instructs the unit 5 for dosing interruption to end the interruption in the supply of material. Upon resumption by the material supply unit 6, the arithmetic unit 4 checks the fulfillment of the condition

CHR-trb o (3)

i

L

where P, is the value of the weight of the material being metered, received from the weight measuring unit 3 at the time of the end of the dispensing. When condition (3) is satisfied, the arithmetic unit 4, through the metering control unit 9, signals the end of the metering to the input of the feeder selection unit 10. The feeder selection unit 10 instructs the unit 6 to turn off the feeder supplying the material and selects the next one according to the recipe. Thereafter, the entire dosing cycle is repeated in the sequence reviewed.

Claims (2)

1. Authors certificate of the USSR 415S08, cl. 0-01 0-13 / 24, 1971. 2. USSR author's certificate No. 434387, class, O-05D11 / 13, 1973.