SU1179058A1 - Method of controlling wood fibre drying process - Google Patents

Abstract

The method of controlling the drying of wood fiber by changing the fuel consumption depending on the amplitude of the temperature fluctuations of the heat carrier and the main correction signal according to the degree of grinding of the fiber, in order to measure the drying quality of the fiber by reducing the residual moisture in the fiber , adjust it according to the degree of grinding and, as a task, enter into the main correction signal for fuel consumption change. ate with us G5

Description

one

The invention relates to a drying technique, in particular to the automation of the fiber drying process in the production of fiberboard.

The purpose of the invention is to improve the quality of drying by reducing the residual moisture in the fiber.

The drawing shows a block diagram of a control system implementing the method.

The control system contains a sensor of 1 degree of grinding of the fiber, a drying unit 2, a computing unit 3, a regulator 4 of the oscillation frequency of the drying agent temperature, a sensor 5 of the frequency of oscillation of the temperature of the heat carrier, pipelines 6-8 for supplying the heat carrier, fuel and wood fiber respectively, heating furnace 9, generator 10, heat carrier temperature controller 11, temperature sensor 12, regulator 13 installed in the fuel supply pipe 7, secondary fiber moisture device 14 and fiber moisture sensor 15.

The method of controlling the wood fiber drying process is as follows.

The signal from the sensor 1 degree of grinding, installed at the input of the drying unit 2, through the computing unit 3 is supplied to the controller 4 frequency. This regulator also receives a signal from the sensor 5 of the frequency of fluctuations in the temperature of the coolant installed in the pipe 6 at the outlet of the heating furnace 9, operating on fuel supplied through the pipe 7. The error signal of the frequency regulator 4 is a reference to the frequency of generation of the generator 10, which receives information from the sensor 1 degree of grinding of the fiber. The output of generator 10 varies sinusoidally. The frequency of the sinusoidal oscillation is adjusted according to the degree of grinding of the fiber according to an experimentally found algorithm.

e - 00 + si

190-200 C - supporting temperate about heat carrier tour

582

A is the amplitude of vibration (1015 ° C).

The signal in the form of oscillations with a known amplitude and frequency enters the chamber. Setting the temperature controller 11. The variable is received from the controller 12 from the heat carrier temperature sensor 12 at the exit of the heating furnace. The error signal of the temperature regulator is fed to the regulator 13, installed on the fuel supply pipe 7.

The residual moisture concentration in the material being dried is determined by the formula

jb aw b ci 4 s

where U) k is the frequency of fluctuations in the temperature of the heat carrier at a constant amplitude;

5 a, b, c are constants determined experimentally. The value is monitored by a secondary moisture device 14 connected to a humidity sensor 15 installed at the outlet of the drying unit 2, to the input of which a fiber-wood mixture is fed through line 8.

With the help of the generator 10 and the controller 11, the impact on the regulatory body 13, installed on

The fuel supply pipe 7 creates a forced sinusoidal fluctuation of the temperature of the coolant at the exit of the heating furnace 9. The temperature of the coolant is measured with the aid of sensor 12. Computing unit 3 when changing the degree of grinding of fiber,) - & on the algorithm calculates

oscillation frequency. The output signal 5 of the computational unit enters the regulator 4 of the oscillation frequency of the drying unit. The frequency controller 4 also receives the output signal from sensor 5, which is proportional to the current frequency of change in the temperature of the heat transfer medium.

The error signal of the frequency adjuster 4 is a reference for the regulator 11. The system around the circuit 5 of the generator 10 and the regulator 11 influences the regulator 13 to provide a predetermined frequency of temperature of the coolant. . Thus, the system carries out an adjustment of the frequency of changes in the temperature of the heat transfer 1790584 and (: nanost orness and melieni pellichish. Degree of chomol fiber.

Claims (1)

METHOD FOR CONTROLING THE DRYING PROCESS OF WOOD FIBER by changing the fuel consumption depending on the amplitude of fluctuations in the temperature of the coolant and the main correction signal according to the degree of grinding of the fiber, characterized in that, in order to improve the quality of drying by reducing residual moisture in the fiber, the frequency of temperature fluctuations is additionally measured coolant, adjust it according to the degree of grinding and, as a task, enter it into the main correction signal to change the fuel consumption.