RU1792730C - Device for automatic control of mixing process mainly for diluting liquid glass - Google Patents

Abstract

Usage: the invention can be used in the chemical industry to control the process of dilution of liquid glass in the production of carbon dioxide white soot and allows to obtain liquid glass of a given density. SUBSTANCE: device comprises a diluted liquid glass temperature sensor 3, a converter 4, a regulator 5, an actuator 6 for supplying water, a water temperature sensor 7, a converter 8. a regulator 9, an actuator 10 for supplying a coolant, a scaling unit 11, an adder 12, a block 13 signal delays and master 114, 2 ml.

Description

The invention relates to the field of automation of processes of chemical technology and can be used in the chemical industry to control the process of dilution of liquid glass in the production of carbon dioxide white soot. Water glass is diluted to a density of 1.08 ± 0.005 g / cm3 and a temperature of 50-80 ° C.

The aim of the invention is to improve the quality of diluted water glass by increasing the accuracy of regulation.

Fig. 1 is a schematic diagram of a device for automatically controlling a liquid glass dilution process; in Fig. 2, a nomogram relating the temperature of diluted liquid glass, the temperature of water supplied to dilute liquid glass with the density of diluted liquid glass.

Concentrated liquid glass from autoclaves; It is fed into diluent 2, and water heated in heat exchanger 1 also flows there. The device comprises a liquid glass temperature sensor 3 connected through a converter 4 and a regulator 5 to an actuator 6 for supplying water, a water temperature sensor 7, a converter 8, a regulator 9, an actuator 10 for supplying heat transfer agent, a scaling unit 11, an adder 12, a delay unit a signal 13 and a setter 14. The output of the water temperature sensor 7 is connected through a series-connected converter 8, a scaling unit 11, an adder 12 and a signal delay unit 13 to the second input of the water supply controller 5, the output of the converter 8 Melting bodies of water through the regulator 9 is connected to an actuator 10 supplying the heat medium, the second input of the adder 12 is connected to the output of the sensor 14 za-.

The regulation of the process of dilution of liquid glass using this device is carried out according to the following algorithm:

ta; pz f (t2: V2) with Vi; p const (1)

t3; pZ f (t2) at V2 Uzad Const, (2)

while t.3 is directly proportional to t2

1З: рЗ f (/ 2) At t2 1, the const. AT THIS (3)

t.3 is inversely proportional to V2 Pl P3-P2 (4) Р2 ЦР4 - 0.2) + (Р5 - 0.2) + 0.2 + С (5) Рз Ихз: рз). (6) Ps f (t2) (7) RA const at a given value of pz where Vi is the current value of the flow rate of concentrated liquid glass:

0

5

0

5

0

5

0

5

V2 - current value of water consumption for glass dilution:

pi - current density value of concentrated liquid glass:

rz - the current value of the density of diluted liquid glass;

ti is the current temperature value of concentrated liquid glass;

t2 is the current value of the temperature of the water supplied to the dilution of concentrated liquid glass;

t.3 - the current temperature value of diluted liquid glass;

Uzad; 1 back; REED - set value of the corresponding parameter;

Pi is the signal generated by block 5, which is proportional to the temperature difference of the diluted liquid glass and water supplied to the dilution of the concentrated liquid glass;

P2 is the signal generated by blocks 7, 8. 11, 12,13, 14, proportional to the temperature of the water supplied to the glass dilution, the FM signal and signal C;

Pz is the signal generated by blocks 3, 4 proportional to the temperature value of diluted liquid glass;

P4 - signal setter 14;

PS signal generated by blocks 7, 8 is proportional to the value of the temperature of the water supplied to dilute the liquid glass; .

c is the level of bias of signal P2 into the working area.

The nomogram shown in FIG. 2 was obtained by diluting concentrated liquid glass having a temperature of -115 ± 2 ° C and a density of 1.4 g / cm3 ± ± 0.01 g / cm3 with industrial water, the temperature of which was stabilized at the following in series variable preset levels - 20 ° C, 30 ° C: 40 ° C; 50 ° C; 60 ° C; 70 ° C. These dependencies are constructed as follows: (let us consider the example of diluting concentrated liquid glass with water heated to a temperature of 20 ° C).

The temperature sensor 3 of diluted liquid glass will show a temperature of 20 ° C in the case when it will only measure the temperature of water (there will be no glass), therefore a temperature of 20 ° C corresponds to

the density of water is 1.0 g / cm. When there is no water, and only concentrated liquid glass comes in, the sensor will show a maximum temperature of 115 ° C, which corresponds to a density of concentrated glass of 1.4 g / cm.

When concentrated liquid glass was introduced into the mixer, so much twenty-degree water was supplied so that the temperature of the diluted liquid glass was 40 ° C. At the same time, its density was 1.085 g / cm3.

Based on these points, the dependence of the binding density and temperature (of diluted liquid glass upon dilution of concentrated glass with industrial water, the temperature of which is stabilized at -20 ° C.) Was constructed. The dependencies connecting the density and temperature of diluted liquid glass when diluting concentrated glass with technical water were diluted whose temperature is stabilized at 30 ° C; 40 ° C: 50 ° C; 60 ° C; 70 ° C; i.e., the obtained dependences cover the entire range of temperature and the ratio of diluted water glass and the temperature of the water that is supplied to the dilution.

 The nomogram is valid for concentrated waterglass having a luminosity of 1.4 ± 0.01 g / cm3 and a temperature of 115 ± 2 ° C. When these conditions change, the nomogram is refined.

 The device operates as follows |.

, In diluent 2 serves concentrated liquid glass prepared by an autoclave having stable parameters - temperature 115 ± 2 ° C and density 1.4 g / cm3 ± 0.01 g / cm3. The stability of these parameters is ensured by the autoclave separation automation system, which maintains at a constant level the amount of silicate loaded into the autoclave — water, boiling time, temperatures and pressure of hot steam. There (in a diluent), the process water heated to a predetermined temperature value is supplied to the process water heated to heat exchange 1. Stabilization of the water temperature at a predetermined level is carried out in the heat exchanger 1 by a water temperature control loop, consisting of a water temperature sensor 7, a converter 8, a controller 9, and a heat transfer medium 10.

By setting the regulator 9, the required water temperature is set. Using the adder 14 using the adder 12 and the signal delay unit 13, they form a signal to the regulator 5, thereby setting such a flow of heated water to dilute the concentrated liquid glass at which the density of the diluted liquid

Glasses (i OTOHPI about the product l. defined "by its temperature)" will be the key.

With an unplanned increase in the flow rate of concentrated liquid glass (in accordance with the TOPL balance equation), the density and proportionally the temperature of the diluted liquid glass will increase, which will lead to an increase in the signal Pz. With the imbalance of the signals of RE and P2

0 controller 5 will work out an increase in the RE signal and change the Pi signal in such a way that it will lead to an increase in water consumption and, accordingly, to a decrease in the density and temperature of the diluted liquid

5 and, as a consequence, to a decrease in the RE signal. The process of changing the water flow rate and decreasing the Pz signal will continue until the PZ signal becomes equal to the PZ signal (assignment to regulator 5), which indicates that the density of the diluted liquid glass expressed through its temperature again becomes equal to the set .

Similarly, the device fulfills a disturbance along the flow channel of concentrated liquid glass in the direction of its decrease. The RE signal decreases, the Pi signal changes, decreasing the water consumption until the RE becomes equal to the RE (task), which indicates the achievement

0 is the density of diluted liquid glass of a predetermined value.

According to technological requirements, the temperature of the finished product should be varied within the range of 50-80 ° С

5 with constant preservation of its predetermined density, which dictates the need for a corresponding change in the temperature of water supplied to the dilution of concentrated liquid glass, with

0 maintaining a constant consumption (so that the density of the product does not change). This is done by changing the setting of the controller 9.

 Suppose that the temperature of diluted liquid glass is to be maintained at 50 ° С, and the density is 1.08 g / cm3. In this case, the task of the regulator 9 is determined by the nomogram and set to maintain the water temperature

0 at the level of 35 ° С. The temperature regime of water for dilution is determined as follows: on the nomogram on the abscissa (density of diluted liquid glass) from a point corresponding to a density of 1.08

5 g / cm., A line is drawn parallel to the ordinate axis (temperature of diluted water glass). From a point on the ordinate axis corresponding to 50 ° C, a line is drawn parallel to the abscissa axis. From point A of the intersection of these lines, a line is drawn parallel to the series of curves on the ordinate axis. The intersection point B will give the value of the temperature of the water supplied to dilute the concentrated liquid glass.

Then, the setter 14 forms the task of the quality regulator 5 to establish such a heated water flow rate at which the temperature of the finished product will be 50 ° C, which corresponds to a product density of 1.08 g / cm3. The finished product is obtained with a temperature of 50 ° C and a density of 1.08 g / cm3.

Suppose you want to change the temperature of the finished product to 80 ° C with a constant density of 1.08 g / cm,

In a similar manner, it is determined from the homogram that in this case, the temperature of the heated water should be 71 ° C. The task of the regulator 9 is changed to maintain the water temperature at 71 ° C. The output signal of the controller 9 will increase the coolant flow rate, the water temperature will increase to a predetermined value, which will lead to an increase in the RB signal and, accordingly, the Ra signal. An increase in water temperature will, in turn, lead to an increase in the temperature of diluted water glass and, accordingly, an increase in the RE signal. In order for the flow rate of heated water to remain constant and, accordingly, the density of liquid glass to remain constant, it is necessary that signals 2 - reference and RE - vary synchronously in time. PZ signal measurement

is caused by a change in water temperature, and a change in RE signals is caused by a change in the temperature of water glass. The RE signal changes with some delay due to an increase in the inertia of the sensor 3 caused by the inlay of the thermometer cover. The synchronism of their change in time is ensured by the inclusion in the device of the delay unit 13 of the signal Pr. (The delay time of the signal P2 by the unit 13 is adjusted so as to compensate for the inertia of the sensor 3). A diluted water glass is obtained with a temperature of 80 ° C and a density of 1.08 g / cm3.

The scaling unit 11 is designed to combine slopes of the characteristics of different types of temperature sensors 3, 7, because the same sensors are used in this device, the coefficient of block 11 is 1.0.

Thus, the technical and economic advantages of the claimed device consist in improving the quality of the diluted

liquid glass by increasing the accuracy of regulation, because when disturbances are made both in the consumption of the initial product and in the change in the temperature regime of the process, diluted liquid glass is obtained with a density of 1.08 ± 0.005 g / cm3 and a temperature of 50-80 ° C, which meets the requirements of the technology.

Claims (1)

SUMMARY OF THE INVENTION A device for automatically controlling a mixing process primarily for diluting liquid glass, comprising a diluted liquid glass concentration sensor connected through a converter and a regulator to an actuator for supplying water, characterized in that, in order to improve the quality of diluted liquid glass by increasing the accuracy of regulation , it additionally contains a water temperature sensor, a converter, a regulator and an actuator for supplying coolant, scale a batching unit, an adder, a signal delay unit and a setter, a temperature sensor is used as a diluted liquid glass concentration sensor, the output of a water temperature sensor through series-connected transducers, a scaling unit, an adder and a signal delay unit are connected to the second input of the water supply regulator, the output of the converter water temperature through the regulator is connected to the actuator of the coolant supply, the second adder input is connected to the setpoint output. Pj t Ј Tie. I AM 1.0 1.91 No. 1.1) t, W 1.9 4fff W W 1.09 1.1 W l, ti