SU965503A1 - Method of automatic control of low inertial reactor operation - Google Patents

Description

The invention relates to methods for automatically regulating a chemical reactor and can be used in all sub-branches of the chemical industry, as well as in the food industry, non-ferrous metallurgy and in a number of other branches of the national economy.

There is a method of automatically regulating a reactor with a tank closed in a pH control loop, which implements the following operations; measuring the actual pH value, comparing it with the set pH value, changing the supply of the reagent according to the results of comparing the actual and set pH value fl

The disadvantage of this method is that the compensation of disturbances emanating from different sources begins only after the appearance of unbalance on the element comparing the actual and given pH values, which prevents stabilization of the controlled parameter, especially at a high frequency of disturbances and low inertia of the reactor. .

The closest to the proposed is the method of automatic

control by measuring the costs of neutralizing and neutralizing reagents at the reactor inlet and the degree of pulp neutralization at the reactor exit, determining the ratio of reagent costs, changing the set value of the ratio of reagent costs by measuring the degree of neutralization

10 pulps, comparing the actual and set values of the ratio of reagent consumption and the change in the supply of neutralizing reagent according to the results of the comparison of the values of the corresponding. spending reagent costs 2j.

15

However, when the reagents stay in the rea, who does not exceed 2-3 minutes (as is the case in SAN devices, as well as, for example,

Claims (2)

20 in fast-acting tubular reactors of various designs), the time constant of the reactor does not exceed the constant time of the pH measurement circuit and is comparable with the time constant of the measurement circuits of reactant flow and control of the neutralizing agent & 30 control and regulation). For this reason, a sufficiently complete and reliable compensation of disturbances in reagent consumption, in reagent concentrations, conditions of their mixing in the reactor (associated, for example, with the pressure instability of gaseous reagents) is not achieved, which does not allow stabilizing the technological process and performance indicator of the reactor. The aim of the invention is to create automatic control systems for low-inertia reactors with increased speed and an improved quality of stabilization of the neutralization process. The goal is achieved by the fact that, according to the method, when adjusting the cost ratio of the neutralizing and neutralizing reagents, correction is made for the rate of change in the degree of neutralization of the pulp at the reactor output. At the same time, the performance of the aBTOMaTH4ecKo regulation system is significantly improved and / thereby the quality of the neutralization control is improved, the overspending of the neutralizing agent (for example, gaseous ammonia) is reduced at. regulation of low-inertia reactors and reduced production costs. The drawing shows the scheme of the method. Reagents (e. G., Phosphoric acid and ammonia gas} through actuators 1 and 2 and flow measurement sensors 3 and 4 are fed to reactor 5. A sensor .6 is installed on the discharge line of the slurry, the output of which is connected to the inlets of the unit 7 of the differentiation and summation of the block 8. The output of the block 7 is also connected to the input of the summed-up block 8, the output of which, as well as the output of the block of task 9, is connected to the input of the pH regulator 10. The output of the pH regulator 10 is connected to the setting device 11 of the regulator 12 ratio The reagent consumption at the reactor inlet to the inputs of the controller 12 is also connected to the outputs of the flow sensors of reagents 3 and 4, and the output of the controller 12 is connected to the actuator 2 at the supply of neutralizing reagent. reagents and mixing conditions in the reactor (but with constant values of reagent consumption), the change in the degree of neutralization of the pulp almost instantaneously, due to the presence of Differentiation unit 7, goes to l torus 10 pH (degree of neutralization .pulpy). The output of pH controller 10 changes the reference set to controller 12 of the flow ratio. reagents: a. an unbalance of the actual and a given value of the ratio of reagent consumption leads to a change in the consumption of the neutralizing reagent by acting on the executive body 2. the actual value of the ratio of reagent consumption with its set value coming from the setter 11. According to the comparison results, the controller 12 makes a change in the supply of the neutralizing reagent by per executive organ: n 2. Claims of the invention in order to stabilize the neutralization process by improving the quality of regulation, in regulating the cost ratio of the neutralizing and neutralizing reagents, additional Corrective correction of the rate of change of the degree of pulp neutralization at the reactor outlet. Sources of information taken in. during the examination. 1.- Maisel I.A. and others. Automation of production of phosphorus and phosphorus-containing products. M., Himi, 1973, p. 176-177, fig. 111-13. 2. The same with 178, fig. 111-14a. Neutralisuepia / zeage / n - / iet / mpa / fi / ffvesfea / reagemt ffyjTMA