SU1044930A1 - System of automatic control of process of drying fodders - Google Patents

Abstract

AUTOMATIC REGULATION OF THE DRYING PROCESS OF THE FEEDS In a pneumatic drum dryer, contains a feed loading controller, the inputs of which are connected to the product humidity and temperature sensors in the drying drum, and the fuel consumption controller, which inputs are connected to the gas temperature sensors in the furnace and moisture content, characterized in that, in order to improve the accuracy, in the communication line of the product humidity sensor with the raw material loading controller, an auto-tuning circuit has been set to a predetermined temperature of the gases in the drying The drum containing the command pulse generator and associated with the latter is a sequentially installed controlled integrator, a memory element and an error accumulator for the current and predetermined humidity of the product, and an additional regulator is installed in the communication line of the gas temperature sensor in the drying drum with the raw material loading regulator. torus associated with the gas temperature sensor in the firebox.

Description

The invention relates to a drying technique and can be used, juveno, in particular for drying agricultural products in pneumatic drum dryers.

. A system is known to automatically control the process of drying feeds in a pneumatic drum dryer, which contains a feedstock loading controller, the inputs of which are connected to humidity sensors of the product and gas temperatures of the Drying drum, and a fuel flow controller that inputs are connected to sensors of gases temperature in the Furnace and the humidity of raw materials Cl.

However, the known system does not provide the required accuracy.

The purpose of the invention is to improve accuracy.

The goal is achieved by the fact that in the automatic regulation system of the drying process of feed in a pyewater drum dryer containing a feedstock loading controller, the inputs of which are connected to the sensors of the Product Humidity and gas temperature in the drying drum, and the fuel consumption controller whose inputs are connected to sensors of the gases in the furnace and the moisture of the raw material tehsheratura, in addition, in the communication line of the product humidity sensor with the raw material loading regulator, an auto-tuning loop is set for the specified gas temperature in The C5Arban contains the command pulse generator and associated with the latter, a sequentially installed controlled integrator, a memory element and an error accumulator for the current and specified product humidity, and an additional control is installed in the communication line of the gas temperature sensor in the drying drum with the regulator. torus associated with the temperature sensor gases in the furnace.

The drawing shows a block diagram of the proposed system.

The system contains a heat generator drum 2, loading window 3, conveyor 4, cyclone 5.

There are two control loops for adjusting the mode. The first consists of a sensor 6 for the temperature of gases in the furnace, a regulator 7, and an actuator 8 that changes the consumption of fuel and air for its combustion. The reference on the controller 7 is formed in accordance with the humidity of the raw material using the setting device 9 or the sensor 10 of the humidity of the raw material.

The second control loop consists of a sensor 11 of gas in the drum in the drum, installed at the beginning of the constant drying speed zone, an additional regulator 12, a regulator 13 for loading the raw material, an actuator 14 that changes, for example, the height of the bitter 15 of the conveyor 4. Additional the controller 12 is connected to the sensor b of the temperature of the gases in the furnace, through the corrector 16.

The task on the controller 13 of the raw material load is formed by the setting device 17 when the system is operating in manual control mode, or the accumulator 18 of the error of the current and predetermined humidity of the product when operating in automatic control mode. With the help of the switch 19, the error accumulator 18 may be feedback-linked to the element 20 cpaDFi established therein. Through the switch 19, the accumulator 18 can also be connected to the memory element 21 via the comparison element 22, the second input of which is connected to the product humidity adjuster 23. The input of the memory element 21 is coupled with an integrator 24 sensing signals from the humidity sensor 25 of the product. The error accumulator 18, the memory element 21 and the integrator 24 connect the control circuits to the generator 26 command pulses. In this case, the integrator 24 is connected to the generator via an inverter 27. A switching mode switch 28 is connected to the switches 19, 29 and 30 of the operating modes.

The system operation is provided in manual and automatic modes.

Sistemgg works as follows.

In the automatic mode, the temperature control loop of the drying agent maintains the temperature in Tonice at a predetermined level by means of the regulator 7 by changing the fuel consumption. The predetermined value of fuel consumption is formed by the setting device 9 in accordance with the moisture content of the wet mass, as determined with the help of an express analyzer. There is also provided for the automatic generation of the initial temperature setpoint by the drying agent by means of the flow sensor 10.

The continuous signal of the on-line moisture meter 25 is fed to the integrator 24, where it is averaged. A pulse generator 26 at uniform intervals fgc.p issues commands to stop the integration and allow the signal to change in memory element 21, where the signal value at the end of the integration is stored. In element 22, the new. Average moisture value of the product is compared with the specified value — and the mismatch with the corresponding sign is passed through switch 19 to

input of accumulator 18 mismatch of current and predetermined humidity is about. duct. In the case of EMF in the measuring diagonal of the bridge of the accumulator 18 acting after conversion and amplification to the balancing motor, the latter moves the slider to reach the equilibrium of the circuit. At the time of equilibrium, the second-molar motor of the second-moth re-chord, also associated with the electric motor, stores the signal value even when the equilibration scheme is turned off. Thus, when applying a j-resolving pulse from generator 26, drive 18 performs the operation

o, dG (), where ± u) -. :: UJ - - uJ - mismatch

1 1 I O M

averaged current and desired product humidity;

U) Q - the initial value of the signal in the accumulator j

1 - transfer coefficient; .- a drum temperature setpoint generated at the output of the accumulator.

This control structure provides an auto-tuning of a predetermined temperature value in a tumble dryer in accordance with varying drying conditions. The temperature setpoint in the drum remains unchanged as long as the moisture content of the drying product corresponds to the setpoint, while the optimal setpoint is set ahead in time tocp compensates for the delay by averaging the signal in the integrator 24.

Comparison of the current and setpoint temperatures in the drum in the controller 13 of the raw material load produces a signal that reduces the load, if it increases it otherwise.

Corrector 16 is an amplifier with a gain factor kj. Since the characteristic of the supplementary controller 12 has

view

 ivyh - () - io, where and ", - the value of the output signal

OIL

regulator;

Up, is the signal corresponding to

0 value of the adjustable parameter (U. t):

and a signal for setting the value of pe30 (A of the parameter to be housed; Up is the setting signal, usually 5 but corresponding to the middle of the range of variation; then the sensor 11 of the gas temperature in the drying drum is connected with the correcting regulator 13 through the additional regulator 12, the parameter setting line and the midpoint which is connected to the sensor 6 of the temperature of the gases in the furnace through the equalizer 16, gives the lower value of the magnitudes, 2 (where t ° is the temperature of the gases in the furnace). The upper value is determined by the expression

0 Bb, x, -S () t -jvy- the upper value of the temperature in the drum.

If, then the range of change of the signal at the output of the regulator 12 is very weakly dependent on the temperature of the gases in the furnace

., - Ueb, x,.) BS-tT.

This ensures autonomy

0 control loops of the proposed system.

In this way, the accuracy of controlling the process of the substance will be improved and, as a result, the quality of the finished product will increase.

Claims (1)

SYSTEM OF AUTOMATIC CONTROL OF THE PROCESS OF DRYING OF FEEDS in a pneumatic drum dryer, containing a raw material loading regulator, the inputs of which are connected to the product humidity and gas temperature sensors in the drying drum, and a fuel consumption regulator, the inputs of which are connected to gas temperature sensors in the furnace and the humidity of the raw material, characterized in that, in order to improve accuracy, in the communication line of the humidity sensor of the product with the raw material loading regulator, a self-tuning loop for the gas temperature in the dryer drum is set containing a command pulse generator and a sequentially installed controlled integrator, a memory element and a drive for mismatching the current and set humidity of the product, and in the communication line of the gas temperature sensor in the drying drum with a feed loading regulator, an additional regulator connected to the gas temperature sensor is installed • in the firebox. . SU „L 044930