SU1579542A1 - Automatic control system for installation for drying compressed air - Google Patents

Abstract

The invention relates to systems for the automatic control of air drying processes and can be used in the chemical and construction industries, in particular, for the pneumatic transportation of the raw materials of the glass batch in the dosing and mixing workshops. The purpose of the invention is to improve the accuracy and reliability of plant control. The automatic control system for drying compressed air contains adsorbers 1 and 2, electric air heater 3, electromagnetic shut-off valves 4 and 5, air distribution valves 6 and 7, control units 10 and 11 with alarm, temperature control unit 12, moisture meter 13, air pressure sensor 14 , temperature sensors 15 and 16, actuators 17 and 18 of the electromagnetic shut-off valves, actuator 19 of the electromagnetic air distribution valve, temperature measuring unit 20, actuator 21 of the electric air heater, element 22 delays, element 2И 23, generator 24 pulses, element 2 OR 25, element 3 OR 26, amplifiers 27 and 28, button 29 "Start", button 30 "Stop", button 31 "Elimination of the accident" and trigger 32. 3 Il.

Description

(21) 4220630 / 23-26

(22) 04/02/87

(46) 07.23.90. Bul Number 27

(71) Borska specialized design and technological organization "Stekloavtomatika

(72) C. V. Efremenkov, Yu. B. Subbotin and B. N. Pestov

(53) 66.012-52 (088.8)

(56) USSR Copyright Certificate No. 610550, cl. B 01 D 53/26, 1978.

Operation manual УОВ-М1- -79-РЭ for the installation of air drying UOV-ЗОМ1 type. Association “Kurgankhimmash.

(54) AUTOMATIC CONTROL SYSTEM OF INSTALLATION FOR COMPRESSED AIR DRYING

(57) The invention relates to systems for the automatic control of air drying processes and can be used in the chemical and construction industries, in particular, for the pneumatic transportation of the raw materials of the glass batch in the dosing and mixing workshops. The purpose of the invention is to improve the accuracy and reliability of plant control. The automatic control system for the compressed air drying with compressed air of g. Adsorbers I and 2, electric air preheater 3, solenoid shut-off valves 4 and 5, air distribution valves 6 and 7, control and alarm units 10 and 11, temperature control unit 12, moisture meter 13, air pressure sensor 14, temperature sensors 15 and 16, actuators 17 and 18 of the electromagnetic shut-off valves, actuator 19 of the electromagnetic air-distributing valve, temperature measuring unit 20, actuator 21 of the electric air heater, elect 22 ent delay element 2I 23, pulse generator 24, the element 2 or 25, Zili element 26, amplifiers 27 and 28, a button 29, "Start button 30" Stop button 31 "Removal of the accident and the trigger 32. 3 yl.

J

Non air

YU

The invention relates to automatic control systems for air drying processes and can be used in the chemical and construction industries, in particular, for the pneumatic transportation of raw materials of the glass batch in the dosing and mixing workshops.

The aim of the invention is to improve the accuracy and reliability of plant control.

FIG. 1 is a block diagram of an automatic plant control system for drying compressed air; in fig. 2 is a block diagram of the time control units and the control and signaling units; in fig. 3 is a block diagram of a temperature control unit and temperature change diagrams depending on the amount of moisture in the exhaust air.

The automatic control system for drying compressed air (Fig. 1) contains adsorbers 1 and 2, electric air preheater 3, electromagnetic shut-off valves 4 and 5, first air distribution valve 6, second air distribution valve 7, first and second time regulating units 8 and 9, blocks 10 and control and signaling, temperature control unit 12, moisture meter 13, air pressure sensor 14, first and second temperature sensors 15 and 16, first and second actuators 17 and 18 of the electromagnetic shut-off valves, starter 19 of the electromagnetic air distribution valve, temperature measuring unit 20, electric air heater starter 21, delay element 22, element 2I 23, pulse generator 24, element IL II 25, element ZIL I 26, first and second amplifiers 27 and 28, buttons 29 "Start , 30 "Stop, 31" Eliminate the accident and trigger 32.

The blocks 8 and 9 (Fig. 2) of the time control are intended to set the operation time of the adsorbers 1 and 2 for air drying and to determine the cyclical nature of their switching. Each block 8 and 9 consists of a trigger 33, a counter 34, digital code adjusters 35 and 36, an element 37. an inverter 38, an element ZILI 39, a waiting multivibrator 40.

The control and signaling units 10 and 11 (Fig. 2) are designed to control and record the moments about the increase in the humidity of dry air and form commands to prematurely switch adsorbers 1 and 2 and decrease the cycle time. Each block 10 and 11 consists of a delay element 41, an element 2I 42, an element 2ILI 43, counters 44-46, decoders 47-49, waiting multivibrators 50-52, triggers 53-55, elements 56- - 58 of the display.

The temperature control unit 12 is designed to control the heating of the air.

in the electric heater 3. Block 12 consists of elements ZILI 59, element 2ILI 60, triggers 61 and 62, element ZINE 63, amplifying elements 64 and 65,

resistors 66 and 67, pulse generator 68, delay element 69, normalizing converter 70, differentiator 71, scaling converter 72 of adder 73, comparison unit 74, and master 75.

In the graph (Fig. 3), the temperature change of curve 76 shows the process of temperature rise with a small amount of moisture in the exhaust air, curve 77 shows an average amount of moisture, and curve 78 shows

with a lot of moisture.

The automatic control system works as follows.

The two adsorbers 1 and 2 alternately receive compressed air from a compressor (not shown) to a pipeline that has a fully modulated check valve 6 installed. Alternating compressed ns-dried air to adsorbers 1 and 2 is alternately supplied by means of an electromagnetic distribution valve 6. Electromagnetic Air distribution valve 6 simultaneously switches the discharge of air into the atmosphere after the regeneration of the adsorbers 1 and 2. The redistribution of the dried air is carried out by the air distribution valve 7. In the original

After the system is started up, the air goes through adsorber 6 through n adsorber 1, and the air dried and heated in air to preheat 3, through valve 7 enters adsorber 2. The ducts at the outlet of adsorbers I and 2 through air distributor valve 7 alternately the design of the valve 7 is connected to the dry air line. After starting the system, the dried air from the adsorber 1 through the valve 7 enters the

dry air line. Part of the dried air through the shut-off valve 4 is supplied to the electric heater 3. The heated and dried air passes through the adsorber 2, regenerates the adsorbent (silica gel) in it and exhausts it into the atmosphere through the air distribution valve 6. At the end of the cycle, adsorbers 1 and 2 switch over. Adsorber 1 becomes regeneration mode, and adsorber 2 switches to air drying mode.

It happens as follows.

After pressing the Start 29 button, the start signal switches the trigger 32 so that at its output a command is issued to open the shut-off valve 5, which flows through the amplifying element 28 to the starter 18 of the solenoid shut-off valve 5. The valve 5 opens and starts supplying compressed air from the compressor to air drying unit. At the same time, the start-up signal enters the temperature control unit 12 and through the elements 2ILI25 - into the adsorber 1 time control unit 8. In unit 8, the operation time of the adsorber 1 for drying air begins. The air distribution valves 6 and 7 are in such a position that adsorber 1 is set to the "Air Drying" mode, and adsorber 2 is set to the "Absorbent Regeneration. The direction of movement of dry and dry air through adsorbers 1 and 2 for this case is shown in FIG. 1. The operation time of the adsorber 1 is set using the digital code sets 35 and 36 of the time adjustment unit 8 and is easily changed to one side or the other. All timing parameters are generated by recalculating the frequency from the 24-pulse generator. The cycle time is selected depending on the season and can vary within 7-12 hours.

The signal from the button 29 "Start in the temperature control unit 12 forms a command to activate the electric air heater 3 and the command to open the shut-off valve 4. Dry air from the canister 1 through the air distribution valve 7, dry air line, the shut-off valve 4 begins to flow into the electric air heater 3. Heated air from the electric air preheater 3 through the air distribution valve 7 enters the adsorber 2. The air temperature at the outlet of the electric air preheater is controlled by The sensors 15 and temperature measurement unit 20 temperature. The air pressure sensor 14 forms a ban on air heating if the shut-off valve 4 is not opened, and the temperature sensor 15 and block 20 form a ban if the air temperature at the outlet of the electric air heater exceeds the allowable one.

The operation time of the electric air preheater 3 depends on the amount of moisture absorbed by the absorbent in adsorber 2, which has entered the regeneration mode, and varies within 0.5-1.5 hours. The control of regeneration of the absorbent is indirectly controlled by the temperature of the air at the outlet of the regenerated adsorber 2. After heating the upper layers of the absorbent (silica gel) in the adsorber 2 to a temperature of 70-80 ° C, the electric air heater 3 is turned off, however, the supply of dried air to the adsorber 2 continues. The heat from the lower absorbent holes is transferred to the upper ones, with the result that the outlet air temperature reaches 90-95 ° C. Subsequently, the absorbent is cooled to a temperature of about 30 ° C and the shut-off valve 4 is closed. The regeneration mode is completed. Since a certain time after the heating of the air is turned off, heat is transferred from

the bottom layers of the absorbent to the top and the intensive removal of moisture continues, the moment of switching off the electric air heater 3 can be predicted from the air temperature at the outlet of the regenerated adsorber 2 and not at 80 or 90 ° C, but earlier, depending on the temperature rise rate. The rate of increase in temperature, as an indirect parameter of humidity, is greater if

About the amount of moisture absorbed by the absorbent is small, and less if the amount of moisture in the absorbent is large. At a higher rate of increase in temperature, measured by the sensor 16, the regeneration time is shorter. If

5, the dry air humidity was greater, the regeneration process is slower and the electric air heater works more. Estimation of the rate of increase in temperature and prediction of the instant of time when the heating is turned off is performed by the temperature control unit 12. The time of operation of the heater and the duration of the regeneration cycle are determined by solving the first order differential equation

25

d T I -t- 1 „b P

where T is the current air temperature at the outlet of the regenerated adsorber 2;

0 dT

-l- is the rate of change of the current temperature;

tn is the average time of heat transfer from the lower to the upper layers after switching off the electric air heater 5;

Thor is the temperature of the end of regeneration (90-95 ° C).

In the temperature control unit 12, the temperature at the outlet of the regenerated adsorber 2 is measured continuously in the regeneration mode, the rate of temperature change is measured. The temperature measurement rate is constantly multiplied by the time tn and is added to the value T.

,, dT

5 As soon as the sum of T -f- becomes equal

The torus, the command to turn off the heating of the air is formed and the countdown of the time for cooling the absorbent begins. The cooling time is in the order of 1 hour.

0 At the end of the air drying cycle in the adsorber 1 in the time control unit 8, a pulse is generated, which is fed to the time control unit 9. In block 9, a command is formed which, through the reinforcement element 27, enters the start-up of the electromagnetic air distribution valve 6 19. The air distribution valve 6 switches in such a way that adsorber 1 is put on the regeneration mode, and adsorber 2 is on the air drying mode. At the end of the cycle, the signal from the output of block 9 through element 2ILI 25 turns on block 8 (air drying in adsorber 1 begins) and block 12 (regeneration mode of adsorber 2 begins). Further operation of the system is similar.

If during the air drying cycle the air humidity at the outlet of adsorbers 1 and 2 prematurely rises, the signal from the moisture meter 13 enters the input of element 2I 23. At the second input of element 2I 23, the signal arrives with a delay of about 10 s through the element 22 . Such a circuit eliminates false short-term signals from the moisture meter 13. From the output of element 2 and 23, a signal of high humidity is sent to the control and alarm units 10 and 11. In these blocks, a similar situation is analyzed. If during five cycles of operation of one adsorber (1 or 2) from element 23, the signal of excessive humidity is sent to the corresponding block 10 or 11 of the control and alarm three times, then in block 10 or 11 of the control and alarm, a preliminary signal and a command to reduce cycle time.

Each signal during the cycle of high humidity also switches adsorbers from one mode to another.

The transition to a shorter work cycle indicates either high humidity of the dry air, or a decrease in the moisture absorbing ability of the absorbent (silica gel).

If the situation of repeating the signal of high humidity three times during a shortened cycle of operation is also repeated, then in block 10 or 11 of the control and signaling system, a ban on the operation of the control system is formed. The prohibition signal from blocks 10 and 11 is fed to the input of the ZILI element 26. From the output of element 26, this signal goes to the second input of the trigger 32 and switches it to the initial state. The shut-off valve 5 closes. An accident indication appears indicating that the absorbent has to be replaced. The emergency blocking is canceled by the button 31 "Elimination of an accident. Premature shutdown of the system can also be accomplished with button 30 “Stop.

Block 8 or 9 of the time control works as follows.

The scheme of blocks 8 and 9 is identical. The difference is that the second output from the flip-flop 33 in block 8 is not used, since on this output a command is generated to switch the adsorbers. In the initial state, when the adsorber 1 and block 8 begin to work, the switching command is not required. Another difference is that

0

the first input of the trigger 33 in block 8, the starting pulse comes from element 2ILI 25, and to the first input of trigger 33 in block 9 - from the waiting multivibrator 40 in block 8. Exit

from the standby multivibrator 40 in block 9 enters the input of the element 25. Since the input and output pulses for blocks 8 and 9 are similar in their functional purpose, and the operation of the blocks is completely identical, in FIG. 2 blocks 8 and 10 are not disclosed to the element base, but only the differences in the addresses of the inputs and outputs are shown. The same applies to blocks 10 and 11, which are completely identical in structure and function.

5 From element 2ILI 25 (or block 8) a trigger pulse is fed to the input of trigger 33. The starting impulse is formed either by the Start button 29, or by the signal for ending the drying cycle from a similar unit. The trigger 33 is switched so that the counter 34 is allowed to recalculate the frequency signal from the oscillator 24. The frequency of the pulses and the number of bits of the counter 34 are chosen so as to ensure the drying cycle time

5 air within 7-12 hours. The air drying cycle time is set using digital code sets 35 and 36, which decipher the state of the meter. At the same time, at the second output of the trigger 33, a command is formed which, through the amplifying

0 element 27 is supplied to the actuator 19 of the electromagnetic air distribution valve. Valves 6 and 7 switch adsorbers 1 and 2 from one mode to another. This command is used only from block 9, since in the initial state the air drying mode is received first by adsorber 1 and then by adsorber 2. Digital code setter 36 is used to set the initial cycle duration. This time, depending on the time of year, can be varied and varied within 7-12 hours. Digital code setting device 35 serves to set a shorter cycle time in case the moisture absorbing capacity of the absorbent has decreased, or in the case of increased humidity of the incoming drying.

5 air. Let us assume that the cycle time using the setting unit 36 is determined by the duration of 8 hours, and the shortened cycle time specified by the sensor 35 is equal to 7 hours.

In normal operation, after 8 hours, a logical "1" is generated at the output of the setting unit 36, which is inverted by the inverter 38. From the output of the inverter 38, a logical "O through the ZILI element 39 goes to the waiting multivibrator 40. At the output 5 of the waiting multivibrator 40, a pulse is generated which switches the trigger 33 to the initial state. For block 9, simultaneously with the switching of the trigger 33, the command is removed from the amplifier 27 and valves 6 and 7

switch to the initial state. The impulse from the standby multivibrator 40 is supplied through element 2ILI 25 to the same block 8 for adjusting the operating time of another adsorber, to block 12 for controlling the heating of the air for regeneration of the absorbent and to block 10 or 11 for monitoring and signaling for counting the number of switching cycles.

If from block 10 or 11 controls and alarms, the second input of ZILI 39 receives a signal about high humidity of dry air, then the drying mode ends prematurely with switching of adsorbers 1 and 2. The signal "High humidity through ZILI 39 element goes to the waiting multivibrator 40, which generates a pulse. The circuit of one time adjustment unit 8 is switched to the initial state, and the other 9 is switched to the air drying time countdown mode.

If in block 10 or 11 the elevated humidity is recorded three times during five cycles, then the second input 2AND-NOT 37 of block 8 or 9 of the time control receives a switching signal for a shorter air drying time, for example, 7 hours. In this case, after 7 The adsorber 1 or 2 works at the inputs of element 2I-NO 37 there are logical "1, and at the output - logical" O, which through the ZILI element 39 and the waiting multivibrator 40 switch the circuit of block 8 or 9 to the initial state and turn on another block 9 or 8 for air drying mode.

Thus, the block 8 or 9 scheme allows you to set different drying times for the sucker 45 fixed 3 times higher

spirit, takes into account a one-time increase in humidity of dry air with the switching of the mode of operation and a systematic increase in humidity with a switch to a shorter cycle of operation.

Block 10 or 11 control and alarm works as follows.

After switching trigger 33 in block 8 or 9 of the time control to the position corresponding to the air drying cycle,

40

air humidity, then the counter 46 records this situation. If, after switching over to a shorter air drying cycle, the counter 45 will register the increased humidity of the air three more times, then the second logical record "1. The decoder 49 decrypts the state so that, at the output of the decoder 49, a pulse appears, which, through a standby multivibrator 52, flushes the counter 46 and switches

from the output of the trigger 33 to the input of the element 2I 45 trigger 55. From the output of the trigger 55 zero

42, through the delay element 41, a permission signal is received to pass from the signal element 2 and 23 "Increased air humidity, if the air humidity is measured by a moisture meter. 13, above normal. The delay in the element 41, which is about 10-20 minutes, is necessary to take into account the inertia of the moisture meter 13. The absence of a delay can lead to a false fixation of the signal "Increased air humidity from the previous cycle, if there was such a situation.

If from element 2И 23 after a time delay the signal “Increased air humidity is received, then from the output of the element

the signal goes to the LED 58, which indicates an emergency situation, and to the input of the element ZILI 26, through which the flip-flop 32 is switched to the initial state. The shut-off valve 5 closes and the compressed air supply to the drying unit is shut off. This situation is equivalent to pressing the button 30 "Stop. The resetting of the flip-flops 53-55 to the initial state is performed by the button 31 "Emergency response.

55 The temperature control unit 12 operates as follows.

Zero signal from button 29 "Start or signals from blocks 8 and 9 on the end of cyc0

five

2 and 42, this signal enters time regulation block 8 or 9 and switches adsorbers 1 and 2 prematurely. At the same time, this signal arrives at counter 45 and trigger 53. Trigger 53 switches so that a zero signal appears at its output. LED 56 indicates that the humidity is high. The counter 45 counts the number of cycles, the humidity of which was higher. If during five cycles three times the input of the counter 45 receives a signal, "The air humidity is increased, then a pulse is generated at the output of the decoder 48, which enters the input of the waiting multivibrator 51 From the output of the standby multivibrator 51, the pulse arrives at the trigger 54, the counter 46 and the element 2ILI 43. Through the element 43, the counter 45 is zeroed, in the counter 46 is recorded "1, and the trigger 54 is switched. From the first release of trigger 54 to block 8

0 or 9 time control is supplied by the com.-nd on the transition to a shorter air drying cycle. From the second output, the zero signal goes to LED 57, which indicates a transition to a shortened cycle.

5, Counter 44 counts the number of drying cycles from one to five. The decoder 47 decrypts the state of the counter 44. When five consecutive drying cycles are counted, a pulse appears at the output of the decoder 47, which through the waiting multi-vibrator 50 flushes the counter 44 and through element 43 - the counter 45. If during five cycles the counter 45 , for example, fixed only once or twice. the humidity increases, then the readout of the counter 45 is zeroed out. If, within five cycles, the counter 45 fixed 3 times the increased

air humidity, then the counter 46 records this situation. If, after switching over to a shorter air drying cycle, the counter 45 will register the increased humidity of the air three more times, then the second logical record "1. The decoder 49 decrypts the state so that, at the output of the decoder 49, a pulse appears, which, through a standby multivibrator 52, flushes the counter 46 and switches

trigger 55. With the release of the trigger 55 zero

trigger 55. With the release of the trigger 55 zero

the signal goes to the LED 58, which indicates an emergency situation, and to the input of the element ZILI 26, through which the flip-flop 32 is switched to the initial state. The shut-off valve 5 closes and the compressed air supply to the dryer is shut off. This situation is equivalent to pressing the button 30 "Stop. The resetting of the flip-flops 53-55 to the initial state is performed by the button 31 "Emergency response.

The temperature control unit 12 operates as follows.

The zero signal from the start button 29 or the signals from blocks 8 and 9 on the end of the drying cycle is fed to the inputs of the ZILI element 59. From the output of element 59, the zero signal goes to the first inputs of the flip-flops 61 and 62, which are switched. At the output of the trigger 62, a command appears, which through the amplifying element 65 enters the starter 17 of the shut-off valve 4. The electromagnetic shut-off valve 4 opens and air is supplied from the dry air line to the electric air heater 3. At the same time, the output of the trigger 61 is formed to turn on the heating elements in the electric air heater 3.

A command in the form of a logical "1" arrives at the first input of the ZI-NE 63 element. At the second and third inputs, logical "1 is present in the absence of zero signals from the air pressure sensor 14 and the temperature measuring unit 15.

If there are three logic "1" at the inlet at the outlet of the element 63, a logical "O is formed, which through the amplifying element 64 enters the starter 21 of the electric air heater 3. If the electromagnetic shut-off valve 4 for supplying air to the electric air heater 3 does not turn on and the air is not supplied, the temperature at the entrance of the electric heater 3 begins to grow unacceptably due to the lack of air flow. This triggers the sensor 14 air pressure and the second input element 63 receives a logical "O. Logic "1 appears at the exit of the element 63, and the starter 21 turns off the power supply to the heating elements of the electric air preheater 3. Air heating is similarly turned off if the air temperature at the outlet of the electric air preheater 3 exceeds 240 ° C. In this case, the signal triggers the contact of the temperature sensor 15 in the block 20 and the logical input “O” goes to the third input of the element 63.

The process of absorbent regeneration consists in passing through an adsorber 1 or 2 depending on what costs the regeneration of hot air. The moisture absorbed in the drying cycle by the adsorbent evaporates under the action of hot air and is carried to the atmosphere. The temperature of the lower and upper layers of the absorbent in the adsorber 1 or 2 gradually increases. The humidity of the air that regenerates the absorbent is judged indirectly by temperature. The higher the air temperature at the outlet from the adsorber, measured by thermocouple 16, the less air humidity and less moisture remained in the absorbent. It is advisable to finish the process of air preheating when the temperature of the upper layers of the absorbent reaches 70-80 ° C, since, after the heating stops, the heat transfer from the lower layers of the absorbent to the upper ones continues during the cooling process. As the adsorber is purged with 1 or 2 unheated air, the temperature of the upper layers of the absorbent reaches 90-95 ° C. Essential value has the choice of the moment of disconnection of heating air. With a different amount of moisture absorbed by the absorbent, the temperature variation of the exhaust air is different. With a small amount of absorbed moisture (curve 76, fig. 3) the process of increasing the temperature T of the outgoing

air in time t occurs faster than with a certain medium and large amount of moisture absorbed by the absorbent (curves 77 and 78, Fig. 3). Rate of change

5 temperature -tg for curve 76 will be more

than for curves 77 and 78. From this it follows that the moment of switching off the heating of air t for curve 76 comes earlier and at a lower temperature Tj. At point A it turns off

0 heating and due to heat transfer, the temperature of the upper layers increases from TI to T4 90-95 ° C. If the heating of the air is turned off later, it can occur due to heat transfer from the bottom (- their layers overheat the upper layers of the absorbent, which is undesirable. Since the time of heat transfer from the lower layers to the upper layers can be taken for a certain constant value, then the current the value of the air temperature at the outlet of the adsorber 1 or 2

A and the rate of temperature change can be predicted when a different amount of moisture is absorbed, when the heating of the air goes out.

The change in temperature can be written 5 by the following equation:

T + t-t

0 where T is the current value of the air temperature at the outlet from the adsorber 1 or 2;

dT

dt

- the rate of change of the current theme5

perature;

tn is the averaged constant time during which heat is transferred from the lower layers of the absorbent to the upper ones;

T4 90-95 ° C - the maximum allowable temperature of the air and the upper layers 0 of the absorbent.

The circuit constantly measures the temperature, its speed and calculates the instant of disconnection of the heating of the air. For example, at the current temperature of 60 ° C, the rate of temperature change at the point of 60 ° C, equal to 2 ° / min, and 5 constant tn 10 min, we get 80, i.e., turn off the heating early. And, for example, when

rtT

T 60 ° and 3 ° / min (we get 90 ° C)

It is necessary to turn off the heat. At a higher rate of temperature change (at lower humidity), we obtain a shorter operating time of the electric air preheater 3 by predicting the air temperature at the outlet of the adsorber 1 or 2.

The temperature is measured by sensor 16, and the EMF value is converted by a normalizing transducer 70 into a unified signal. In the differentiator 71, this value is continuously differentiated. At the exit

/ T

differentiator 7 we get, Next

(IT

value of on scale converter 70 multiplied by a constant value. In adder 73, a continuous summation of T and

dT +., dT.

--.- t ". Ka; only sum value + T tn

will be the city of addendum T ,, and the block 74 comparing the formation jwiiyjt,., which through the element of) w-reset the trigger 61 to the original. Ig. the thunder of air ceases. U / thoi, o, air is a hot end. Drops the electrical heater 3 and da-k1, - and the adsorber 1 or 2 to cool them. After switching the trigger 51 m «L to« O forg., The force 68 Forms the impulse which, through the time ti required for cooling the absorbent, switches from a third to its initial state. The shut-off valve 4 for supplying air to the electric air preheater is closed. Similarly, the air is disconnected and after pressing the button .Ston 30. In the case of an event, the signal from button 30 through the second input of element 60 switches trigger 6 to the initial state. Consequently, in this scheme, the current temperature value is measured, its rate of change and the moment of switching off the electrosheater 3 is predicted, i.e., the less absorbed by the moisture absorbent, the less air and electricity consumption.

The use of this technical solution allows you to: set the adsorbers of different cycle times depending on the humidity of the dry air and depending on the decrease in the moisture absorption capacity of the absorbent; it is more efficient to carry out the regeneration mode of the adsorbers not by time, but by a change in air temperature at the outlet of the regenerated adsorber; diagnose pre-emergency and emergency situations; improve reliability and control accuracy.

Claims (1)

Invention Formula The automatic control system for drying the hedgehog i air yoke, containing iit, and the second adsorbers interconnected through the first and second air distribution valves, the electric air preheater, through the first solenoid check valve connected to one of the outlets of the second air distribution valve, the second inlet of which is connected to outlet of electric air distributor, moisture meter, Start button, Stop and Elimination of the accident, first and second temperature sensors, pressure sensor the air heaters, the first shut-off valve and the solenoid valve actuators, the output of the first temperature sensor is connected to the input of the temperature measuring unit, the outputs of the electrical air heater actuator are connected to the electric air heaters and the heater, the outlets of the electromagnetic air distributor a prefrost valve, characterized in order to improve accuracy and reliability By controlling the installation, the HHTIMI.I supplement; O the first and second time control units, the first and second monitoring and signaling units, the hem11 time control unit, the second electromagnetic shut-off valve, the second electromagnetic shut-off valve actuator, delay element, element 2I, generator pulse, element 2ILI, element ZILI, the first and second amplifiers and the trigger, the first input of the temperature control unit is connected to the output of the temperature measuring unit, the second input is connected to the first contact of the Stop and First th input element ZIL And, the third input is connected to the first 5 trigger input, the first contact of the Start button and the first input of element 2IL, the fourth control is connected to the first input of the first control and alarm unit, the second input of the 2IL element and the first output of the first time control unit, the fifth input of the temperature control unit is connected to the first input the second control and alarm unit, the second output of the second time control unit and the first input of the first time control unit; the sixth input is connected to the second temperature sensor; the seventh input is connected to the sensor ohm air pressure, while the output of the moisture meter through the delay element is connected to the first input of the terminal 2I, as well as through the “to-tnt 2I” connected to 0 to the second inputs of the first and second control and signaling units, the third input of the second control and signaling unit is connected to the first output of the second time control unit, the fourth input of the second control and signaling unit is connected to the first 5 contact button "Elimination of the accident and the third input of the first control unit and the accident, the first output of which through the element ZIL And connected to the second input of the trigger, the output of which through serially connected the first amplifier and starter of the second electromagnetic shut-off valve connected to the input of the second electromagnetic shut-off valve, the second and the third outputs of the first control and signaling unit are connected respectively with the second and third inputs of the first time control unit, the first and second outputs of the second block The controls and alarms are respectively connected to the first and second outlets of the second block of the regulated BpfefieHH, the output of the pulse generator is connected to the third and fourth inputs, the first and second blocks of the time control, respectively, the second output of the first control unit P With a button. 0 The first time control unit is connected to the fourth input of the first control and alarm unit, the third output of the first time control unit through the second amplifier and the electromagnetic air distribution valve starter is connected to the first electromagnetic air distribution valve, the first output of the temperature control unit is connected to the electric air heater starter, the second output is connected through the actuator of the first electromagnetic shut-off valve with the first electromagnetic shut-off valve, and The second contacts of the Start, Stop, and Alarm Setup buttons are connected to the ground bus. . in blocks 9.P Vilon / B Newlock21 % t