SU716976A1 - Device for automatic control of neutralization process - Google Patents

Description

The invention relates to devices for automatically controlling the neutralization process in the production of ammonium nitrate and can be used in the chemical industry.

A control device is known, which consists of separate stabilization systems in neutralization devices and contains an ammonia consumption regulator, which stabilizes the load of the apparatus, the ammonia-acid ratio regulator, which supplies the required amount of acid, the neutralization correction regulator - SCC, which, acting on the ratio controller, maintains the acidity of the resulting ammonium nitrate solution within the established limits 1.

The main disadvantage of this control system is the low quality of regulation, due to the use of one actuator (high-flow valve).

It is also known a device for automatic process control.

neutralization in the production of ammonium nitrate, containing an ammonia consumption regulator, a ratio regulator of ammonia and acid consumption with a correction chamber, connected to a coarse adjustment valve of an acid supply, an adjusting regulator, the acidity of an ammonium nitrate solution associated with a solution pH meter

0 ammonium nitrate, a unit for the formation of tasks, a meter for total acid consumption and a valve for fine adjustment of the supply for acid C2.

The disadvantage of this device

5 is a poor quality of regulation, since during adjustment of the ratio of reagents, the fine adjustment valve is in the extreme position and transferred to the set

0 range only after testing the objects and disturbances caused by a change in the acid consumption through the coarse adjustment valve during correlation, which leads to a re-regulation, since the transmission coefficient, time constant and time of a clean lag of the ITS apparatus vary with the load.

Claims (1)

0 The purpose of the present invention is to eliminate the effect of instability of parameters when adjusting the ratio of reagents, to improve the quality of regulation and to reduce the loss of raw materials from juice pairs. - According to the invention, the goal is achieved by the fact that the device additionally contains a logic block for redistributing acid consumption from a fine control valve to a coarse control valve connected to the regulator correction chamber, the ratio of ammonia to acid flow and the fine control valve of the ACID supply; at the same time, one of the inputs of the logical unit is connected to the output of a correction regulator of the acidity of the ammonium nitrate solution / and the second input measures the total flow rate of nitric acid ei-i, the logical unit includes the fine-tuning valve the range associated with the output of the correction regulator, a fine-tuning valve output detection node of the specified range, connected to a control pulse former connected in series to the first memory node, the node and integration, to the second memory node, associated with the ratio controller of ammcak and acid costs, subtraction node, connected to the first node of the memory node, input of the integration node, connected to the second memory node and output of the aperiodic link associated with the total flow meter acid. The device for automatic control of the neutralization process is shown in FIG. 3., and in FIG. 2, one of the options for implementing the node for translating the fine-tuning valve to the middle position and the detecting node; nn the input of this valve from the target range. The device contains a task shaping unit (BFZ) 1, the output of the compressor is connected with the chamber for setting the ammonia consumption controller 2, and a correction for pressure and temperature aji miak is provided in sensor xc ™ of the third 3. The output of the regulator 2 is connected to the regulating valve of the flow rate of the agro-liac 4, the output of the regulator of the ratio of the flow rate of ammonia and acid 5, you: o which are connected to the flow sensors of ammonia 3 and acid 6, which is passed through the valve through coarse regulation: 7, The output of the pH meter of a solution of ammonium nitrate 8, consisting of a series-connected sensor with a measuring and auxiliary electrodes, a high-resistance function converter that serves to linearize the relationship between pH and acid content of a solution of el-primary nitrate and electropneumatic converter, is connected with the output of an acidity correction regulator 9, which forms a PI-Aacon regulation, the output of which is connected to the fine-tuning valve 10 through a logic unit 11, which contains t transfer unit valve fine adjustment in the prescribed range (UE) 12, the node detecting the output of the fine adjustment valve from the set range, (EI) 13, driver control pulse (PI) 14, aperiodic link (LZ) 15, memory nodes (UZ ) 16 and 17, subtraction unit (HC) 18, integration unit (UI) 19, with the output of the regulator 9 connected to the inputs of the translation unit of the fine adjustment valve in the set range -12 and the input of the detection unit of the output valve of the fine adjustment from the set range 13 whose output is connected to the input of the driver pulse control unit 14. The output of the driver 14 is connected with the inputs of the memory nodes 16, 17, the input of the integration unit 19 and the second translation unit of the fine-tuning valve in the set range 12, the output of which is connected to the fine-tuning valve 10, Measuring the total acid consumption 20 through the aperiodic link 15 CBHBSiH with the input of nodes 18 and 15 and the second input of the node memorize an an and 16, the output of which is connected to the second input of the subtraction node 18. The subtracting node is connected with the second input of the integration node 19, vc d; (zapsminani otorrhea through a node 17 connected to the correction chamber 5. The regulator sootnoscheni stroystvo for automatically laziness 15 operates as follows. (.: by the setting unit setting unit; 1 tasks 1; the operator places a load on the device. When ems, the signal for the flow regulator of the ammonia and 2 signals is received, which corresponds to the required load for ammonia, regulator 5, depending on the ammonia consumption and a given ratio ensures that the required amount of acid is supplied through the valve of coarse adjustment 7. The ratio of reagents is chosen so that the resulting solution of 4 m-nitrate has an excess acid content of 3-8 g / l. ammonium nitrate from a given value, the corrector regulator 9 sets the required acidity of the ammonium nitrate solution through node 12 of the path to the fine adjustment valve 10. When the valve 10 leaves the adjusted range, the fine adjustment valve output detection unit from the set range 13 starts the control driver pulse 14; At the beginning of the pulse, node 16 performs a memorization of the signal for the total acid consumption; node 12 turns off regulator 9 and switches the fine adjustment valve 10 to the middle position of the set range, turns on the integration node 19, to which n is the difference between the stored and the current total acid consumption. A portion of the flow rate of acid supplied through the valve half-section of the fine adjustment is redistributed to the coarse adjustment valve, with the result that the fine adjustment valve will be in the established range. After the end of the pulse, unit 17 memorizes the signal fed to the correction ratio correction chamber, unit 12 connects controller 9 to the fine adjustment valve, the output of subtractor 18 is disconnected from the input of the integration unit 19. The duration of the control pulse is proportional to the cross sectional area of the valve fine adjustment, constant aperiodic link time, constant integration time, and inversely proportional to the cross-sectional area of the coarse adjustment valve. Thus, the introduction of the device for the redistribution of nitric acid into the device for automatic control when feeding into the neutralization device, thus eliminating the influence of instability of the parameters of the device or correction of the ratio of reagents in case of a valve of fine adjustment from the set zone, allows high Accurately maintain the acidity of the ammonium nitrate solution in the neutralization apparatus and, therefore, ensures the introduction of a neutralization process with minimal loss of raw materials Claim 1, A device for automatically controlling a neutralization process in the production of ammonium nitrate, containing an ammonia consumption controller. Ammonia and acid cost ratio regulator with correction chamber connected to coarse acid supply adjustment valve, acidity correction regulator of ammonium nitrate solution associated with pH meter of ammonium nitrate solution, unit for forming tasks, total acid consumption meter and valve for fine adjustment of acid supply This is because, in order to improve the quality of regulation and reduce the loss of raw materials with juice steam, it additionally contains a logical block for redistributing acid consumption From the fine adjustment valve to the coarse adjustment valve connected to the ciMmiak-acid flow controller correction chamber and the acid supply fine adjustment valve, one of the inputs of the logic unit is connected to the output of the acidity adjustment regulator of the ammonium nitrate solution, and the second input with a total nitric acid flow meter, 2, The device in accordance with claim 1, 1, of which is that the logic unit includes a valve for the fine adjustment of the valve in the prescribed range associated with the outputs of the correction regulator, the node for detecting the output of the fine adjustment valve from the set range, connected to the generation of control pulses connected in series to the first memory node, the integration node, to the second memory node, associated with the ammonia-acid cost ratio, subtraction node connected to the output of the first memory node, the input of the integration node connected to the second memory node, and the output of the aperiodic link associated with the meter bschego acid consumption. Sources of information taken into account in the examination of 1, USSR Author's Certificate No. 412594, Cl, G 05 V 11/06, 1972. 2, Sat, Automation of Chemical Production, vol. 2, 1971, p. , pacmtop gH saltpeter R