SU449496A3 - Load Control Method - Google Patents

Description

one

The invention relates to a method for regulating the load in wood chopping plants: and is intended for use, for example, in pulp and paper industry.

There is a known method of controlling the load on the mass of wood on the chopping device by measuring the torque value of the drive motor, giving a signal to the converter to obtain an analog signal, which, in turn, is sent for comparison with a given signal and the output signal to the device management

This method does not provide sufficiently high grinding quality.

A distinctive feature of the proposed method is that in addition to measuring the magnitude of the torque of the drive motor, the load on the mass of wood is also measured on the chopping device, signals are sent to the converter about the specified wavelengths which characterize the value of the coefficient of between the wood to be processed and the chopping device, and after comparing with the given signal i, the output signal is directed, in order to keep the coefficient of friction constant, The supply of wood to the chopping device.

Fig, 1, shows the grinding device; FIG. 2 shows a plunger mill with two plungers.

The grinding device 1 is driven by a C 1 clock motor or some other type of engine, for example, a water turbine, with a measured torque. . The power converter converts the torque, and its output signal gives the value for

active energy is a constant, i.e. for

T

force ir friction grinding device. Wood or other milled material is fed down by two transporters, tippers 2 in the form of engine-driven belt conveyors. They are driven by a motor 3 by means of a gear transmission.

4, moreover: this engine can be electric or hydraulic and; have a different speed. For example, it can be driven via a controlled converter 5 (thyristor) powered from an AC network and controlled by the following. o6pa30tvr :. . , ..,;

Load on Hat ejEbijaiofflee. device 1 can be measured in various ways. For example, by means of a torque sensor 6, the output signal of which will be proportional to the normal force that is fed together with the friction force signal (J) from element 7 to the switchgear 8, the output signal of the latter will be proportional to and or to the coefficient of friction. In the adder or differentiator, the signal of the coefficient of friction is compared to the desired value of the signal from the source. A difference signal is obtained that is fed to an integrating control 9 of a known type. The output signal from it is fed to the control circuit of the thyristor 5 and thus controls the current flow, the motor speed, and the down speed of the wood. If, as a result of a change in the friction of the wood and the chopping device 1, the torque of the engine 10 changes, then the quotient changes and the feed rate changes so that the predetermined friction force is restored.

The plunger mill has a plunger 11 and 12 for feeding wood, and the drive element of each of the feeding devices can be controlled in the same way as described. In the diagram:.

D. / - horizontal component of nor-

maximum force K J

Vj (- vertical to the normal force K;

four

llf KI pops ot j

.-Silted.f

Ki-Kfl,}

.

The value of H can be measured, calculate K and K, and these values correspond to the frictional strength of plunger 11 and 12, respectively. The speed of the processing element can also be adjusted separately or together with the feeding element.

Subject invention

The method of controlling the load on the mass of wood on the chopping device by measuring the magnitude of the torque of the drive motor, sending a signal to the converter to obtain an analog signal, which in turn is sent for comparison with a given signal, and the output signal to the control unit , so that, in order to improve the quality of grinding, in addition to measuring the torque value of the drive motor, the load on the weight of the wood on the grinding is additionally measured The device sends signals to the converter about these values, the analog signal from which characterizes the value of the coefficient of friction between the wood to be processed and the grinding device, and after comparing with a given signal, sends an output signal to maintain the coefficient of friction constant to the grinding device.

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