SU1059385A1 - Method for controlling material drying process - Google Patents

Abstract

1. THE METHOD OF MANAGING THE PROCESS OF DRYING 51ATERIAL by regulating the temperature of the coolant from the ILCI HL by varying the consumption of energy carrier depending on the magnitude of the excess temperature of the exhaust coolant over its specified maximum allowable value of KUM. specified minimum values, distinguished by the fact that, in order to increase accuracy, the moisture content of the dried material is measured and This parameter is adjusted to the value of the minimum permissible temperature value% 1 of the spent heat carrier.

Description

2 The method according to claim 1, about tl and h ayush and. and with the fact that the concentration of the starting material is determined, and according to the measured parameter,

The value of the minimum allowable temperature value of the spent heat carrier is recited.

The invention relates to a drying technique and may find application in chemical building, chemical-pharmaceutical and microbiological drainage. A known method of controlling protusom drying material, | The temperature of the heat carrier is at a given level by influencing the consumption of energy carrier depending on the right temperature of the waste heat of the carrier over its specified maximum allowable value, while the consumption of the material supplied to the dryer is measured. depending on the magnitude of the decrease in the temperature of the spent heat exchanger relative to its specified minimum allowable value l. However, the known control method does not provide sufficiently accurate maintenance of the moisture content of the dried material, which varies with, in particular, the speed of the heat exchanger in the volume of the drying unit, the degree of sputtering, the change in the dispersion, the input material and the fractional composition of the input material. The purpose of the invention is to increase the accuracy of regulation. The set goal is reached (WHAT according to the method of controlling the material drying process by adjusting the temperature of the heat carrier by changing the energy carrier consumption depending on the extent of the excess heat transfer temperature above its specified maximum allowable value, change in the raw material consumption, depending on the value of the temperature decrease of the spent heat carrier given the minimum permissible value, the moisture content of the dried material is measured and, according to the measured parameter The key adjusts the minimum allowable temperature value of the spent heat carrier. In addition, the concentration of the source material is determined and the measured minimum value of the temperature of the melted heat carrier is additionally adjusted by the measured parameter. The device for implementing the method for controlling the drying process is shown in the drawing. chamber 2 with a sprayer 3, raw material tank 4, cyclone 5, sensor b of the temperature of the spent heat carrier, sum Ators 7 and 8, setting devices 9 and 10, diode cells 11 and 12, corrector 13 maximum temperature value of the spent heat carrier, corrector 14 minimum temperature value of the spent heat carrier, sensor 15 of the operating temperature of the Tettles osistel, regulator 16 steam consumption, actuator 17, sensor 18, air flow controller 19, actuator 20, source material concentration sensor 21, dried material moisture sensor 22, correctors 23 and 24. The method is as follows. The source material from tank 4 through actuator 20 is supplied to sprayer 3 of drying chamber 2. Here comes working coolant — air, preheated parsi1 in air heater 1. In drying chamber 2, heat and mass transfer occurs between the sprayed suspension particles and (coolant, as a result which is formed by an air gap; 1 is placed in a cyclone 5, where the dried material is separated from the spent coolant. The flow rate of the solution fed to the Dz nebulizer is controlled depending on the size air flow rate (coolant) supplied to the dryer, measured by sensor 18. Necessity of the solution flow rate from tank 4 is supported by sensor 18, controller 19 and Actuator 20, increasing (decreasing) the flow rate by increasing (decreasing) the air flow rate, thereby maintaining the necessary ratio between the costs of the working fluid and the solution; Consequently, the concentration of the solid phase of the gas suspension and the dry chamber 2 is also maintained. The temperature of the working heat carrier, which is entered into the drying chamber 2, is maintained with PS and IU. sensor 15 of the working coolant temperature, the steam flow controller 16 and the actuator 17 by changing the flow rate of the pairs sent to the heater 1. For example, when increasing (decreasing) the value of the working coolant temperature above (below) the specified value, the controller 16 decreases, (increases) the steam consumption to drive the temperature of the working fluid to the specified value. The value of the reference to the controller 16 varies with the sensor's temperature sensor, the sum / controller 8, the setting device 10, the diode cell 12, and the equalizer 13. On the adder 8, the signal of the current value of the coolant temperature measured by sensor 6 is compared with the signal from C: ad sensor 10, and on the sensor 10, the value is set to 6%, 55, 3, and 9, and corresponding to the maximum allowed temperature of the spent heat carrier, i.e., if the signal from sensor 6 is greater (less) than the signal from setpoint 10, at the output adder appears value by ozhitelnogo (negative) signal. The diode cell 12 transmits only the magnitude of the positive signal, which through the corrector 13 reduces the temperature of the operating coolant, changing the setting to the controller 16 until the temperature of the exhaust coolant decreases to the desired value. maximum permissible value. In the absence of a signal from the deed. The cell 12, the corrector 13 does not change the value of the setpoint to the controller 16, which maintains the working coolant temperature at a predetermined value. To prevent a significant increase in the moisture content of the finished dried material, such as caused by an increase in concentration or a change in the chemical composition installation of the solution tank 4 and resulting in a decrease in the temperature of the spent coolant below the minimum possible value of τ & control leads to an increase of "" 1, the waste heat ratio Ositel by reducing the amount of solution that is added to the installation. Maintaining the maximum moisture content of the material produced by the dryer is carried out with the help of adder 7, which receives the signal from sensor 6 tetra of heat carrier, unit 9, which determines the minimum possible value of temperature 1 of the worked coolant, diode cell 11, equalizer 14 by changing the value of knowledge of the flow controller 19. At adder 7, the deviation of the current value of the refined temperature LB is determined heat carrier from the minimum value set by the setting point 9. The equalizer 14 from the diode cell 11 receives only the signal value corresponding to a decrease in temperature below the value specified by the setting device 9. In this case, the corrector 14 changes the reference 19 to the controller 19 until the temperature of the spent heat carrier reaches the predetermined setpoint value 9. In the absence of a signal from diode cell 11, the corrector 14 does not change the value of setting the controller 19, which maintains the required concentration of the solid phase in the gas suspension. In addition, the value of the minimum possible temperature of the heat carrier that was determined by the setting device 9 is adjusted for the moisture content of the waste material and the rate of change in the concentration of the solution entering the treatment. For this, the sensor 22 determines the moisture content of the processed material, the signal of which is fed to the equalizer 24, which compares the signal from the sensor 22 with the reference signal with a reference value corresponding to the specified humidity of the processed material. Further, the error signal is turned off by the corrector 24 and, arriving at the adder 7, changes the value of the minimum allowable value of the temperature of the spent heat carrier. Thus, with an increase (decrease) in the moisture content of the treated material relative to a given value, the setting value of the minimum allowable temperature of the spent heat carrier increases (decreases), decreasing (increasing) the consumption of the solution entering the drying until the desired moisture content of the dried material is restored. Reducing the time required for adjusting the moisture content of the dried material when the concentration of the solution entering the cyhilc solution varies by introducing a correction into the control system. For this, the signal from the concentration sensor 21 is fed to the Corrector 23, which changes with the rank of the adder 7 the value of setting the minimum allowable value of the temperature of the exhaust heat carrier. So with an increase in the concentration of the solution entering the heat treatment, the corrector 23 reduces (increases) the temperature setting of the spent heat carrier, increasing (decreasing) the flow rate of the solution per incubator. Thus, even before the change in moisture content of the processed material measured by the sensor 22 and by changing the concentration of the feed solution, the control unit changes the flow rate

incoming solution, providing a minimum deviation of the moisture content of the processed material.

If the signal from the adder 8 is negative, and from the adder 7 is positive, the diode cells 11 and 12 are not pro, send the appropriate signals, which indicates that the moisture of the dried material and those of the superhears are found

spent coolant within acceptable limits.

The proposed method ensures trouble-free operation of the dryer at its highest possible performance and allows for an increase in the quality of the dried material due to the reduction of moisture in narrower limits.

Claims (2)

1. METHOD OF MANAGING THE MATERIAL DRYING PROCESS by controlling the temperature of the coolant by changing the flow rate of the energy carrier, depending on the excess of the temperature of the spent coolant above its specified maximum allowable value, the change in the flow rate of the Source material depending on the amount of decrease in temperature of the spent coolant from its specified minimum allowable values, characterized in that, in order to improve accuracy, measure the moisture content of the dried material and the measured param labor correct the value of the minimum permissible temperature of the spent coolant SU ..., 1059385 1 & 59385 2. The method according to π '. 1, about t and h a loin and. I mean that they determine the concentration of the starting material and, according to the measured parameter, additionally · correct ’the value of the minimum admissible value of the temperature of the spent coolant ·. 1 *