RU2065199C1 - Regulator for weighing friable materials - Google Patents

Abstract

FIELD: instruments for measuring weight. SUBSTANCE: regulator has weigher, final-control unit, transducer for measuring weight of material, unit for calculation of average value, unit for detection of threshold excess, subtracter, unit for setting area of non-sensitivity, weight setter, generator of control signal. Computing unit, univibrator, button switch, accumulating adder are introduced to accomplish the goal of invention. Signal which corresponds to pre- set volume is used instead of signal which runs from volume detector. Said signal generated corresponding control signal in control unit. EFFECT: simplified measuring, decreased cost of measuring while precision is kept same, simplified design of control unit. 1 dwg

Description

 The invention relates to techniques for measuring mass and can be used to control the processes of batch dosing of bulk materials.

 A known dose-proportioning controller [1] that sets the nominal dose weight, forms a sample from a fixed number of consecutive doses, measures the weight of each dose in the sample, receives the actual deviation of the weight of each dose in the sample from the nominal weight, and generates a control signal for changing the dose volume in the next sample . The inaccuracy in dose adjustment is due to the fact that bulk materials can change their specific gravity.

 A known controller for the process of portioning dosing of bulk materials [2] which includes a dispenser, an actuator, a mass meter, a determinant of the arithmetic mean deviation, a function converter, a subtractor, a functional converter, a control forming unit, a dead band adjuster, a mass adjuster. The disadvantage of this device is that it requires additional measurement of the current volume of each dose in the sample, which complicates the dosing device.

 The aim of the invention is to simplify dosing, reduce its cost, while this should not deteriorate the accuracy of dosing.

 The drawing shows a structural diagram of a device. It includes a dispenser 1, an actuator 2, a calculator 3, a meter for weighing the material to be dosed 4, an arithmetic mean calculation unit, a function calculation unit 6, a single vibrator 7, a subtractor 8, a block for exceeding a threshold value 9, a control signal 10, a dead band adjuster 11, mass adjuster 12, accumulating adder 13, push button switch 14.

 The operation of the regulator is as follows.

где

найденное среднее арифметическое значение отклонений,
М_н номинальная масса дозы.In the dispenser 1 enters the material to be packaged. The package with the dosed product from the dispenser enters the device for measuring mass, which simultaneously receives a signal from the setter, characterizing the value of the nominal mass of the dose. The signal from the master and the mass meter is compared and the error signal is input to the arithmetic mean calculation unit. After receiving the appropriate number of mismatch signals from each dose of the sample, the arithmetic mean value is found. The function arithmetic calculation unit 6 receives a signal of the arithmetic mean of the mismatch value and a signal of the nominal dose mass, after which the calculation

Where

the arithmetic mean of the deviations found
M _{n is the} nominal mass of the dose.

 The value of P is multiplied in calculator 3 by the value of the dose volume (ΔV = P • V) received from the adder, in the memory of which information on the initial set volume of the dose is stored, which is algebraically added with subsequent signals of volume change. The initial dose volume is set in manual mode by pressing a push-button switch, to the normally open contact of which a signal corresponding to the value of the dose volume is supplied. From the second output of the calculator 3, a signal is transmitted through a single-vibrator to the summing unit to enable the summation of the signal stored in the device memory with the volume change signal. The output signal from the calculator 3 through a push-button switch is fed to the input of the control signal generating unit.

 From the output of block 5, the signal of the arithmetic mean value of the deviations also goes to the input of the subtractor 8, where the threshold signal from the setpoint switch 11 of the dead band also arrives. Subtractor 8 generates the difference between the absolute value of the arithmetic mean of the deviations and the given program value of the deviations. This difference is sent to the block for determining the excess of the threshold value 9, where if it exceeds the specified threshold value, an enable signal is generated for block 10, in which a control signal is generated for the actuator 2 to change the dose volume in the next sample. In the absence of exceeding the obtained difference of a given threshold value, the specified change is not performed.

Claims (1)

 A batch process controller for bulk materials containing a dispenser connected to the output of an actuator connected by an input to the output of a control signal generator, as well as a mass meter of the dosed material with a mass adjuster at the input, an arithmetic mean calculation unit and a function calculation unit connected to the second input to the output of the mass master, series-connected dead zone master, subtractor, threshold excess detection unit output value connected to the enable input of the driver of the control signal, characterized in that it contains a calculator, a one-shot accumulator and a push button switch, through the first make contact of which the output of the initial dose setting of the transmitter is connected to the information input of the driver of the control signal connected to the information input the accumulating adder, through the second make contact of the push-button switch, the information input of the driver shaper with drove the data input connected to the calculator, the first information input of which is connected to the output of the function calculation unit and the second data input to the output of the adder, wherein the output timing calculator connected to an input of the monostable, the output connected to the enable input of summation combiner.