SU867886A2 - Method of automatic control of natural water acidification process - Google Patents

Description

(54) AUTOMATIC REGULATION METHOD

PROCESS ACIDICATION OF NATURAL -WATER

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This invention relates to the automation of technological processes and can be used in the energy sector and public utilities in controlling the processes of acidification or alkalization of natural waters.

According to the main author. St. No. 685628 is known for automatically adjusting the acidification process of natural water by bypassing natural water bypassing the mixer, by changing the ratio of the flow rate of natural water and reagent solution into the mixer, depending on the pH of the treated water after the mixer until the end of the bypass P Ts.

The disadvantage of this method is the low quality of the treated water, since when the alkalinity of the source water varies from 0.5 to 3.5 mg-SQ / L existing in real conditions, it does not provide the specified accuracy of stabilization of the pH of the treated water after the mixer.

The purpose of the invention is to improve the quality of the treated water by increasing the control accuracy.

This goal is achieved by additionally measuring the pH of the treated water beyond the bypass, finding the algebraic sum of the received signal with the pH of the treated water after the mixer until the end of the bypass, which changes the ratio of the flow rates of natural water and reagent solution into the mixer.

FIG. 1 is a block diagram.

IS devices that implement a method for automatically regulating the process of acidification of natural water in Figures 2 and 3 are algebraic sum curves of signals from pH sensors.

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The method is carried out as follows.

Claims (1)

Natural water is supplied through pipeline 1 to mixer 2, where it is mixed with acid solution supplied through pipeline 3 using a pump 4 Bypass flow of natural water bypassing mixer 2 through pipeline 5. Bypassing natural water bypassing mixer 2 allows you to shift the range of alkali change after mixer 2 into the working area of the pH sensors, while after the bypass the set alkalinity value of the treated water is restored. The flow rate of natural water through the mixer 2 is measured using the flow meter 6, the ratio of the flow rates of the natural water and acid solution (alkali) in these streams from the flow meter 6 and the pump 4 is stabilized with the help of the regulator 7, which is affected. pump 4 performance. The pH value of the treated α-water after the mixer 2 to the bypass end is measured with the help of sensor 8 by means of sensor 8, the pH value of the treated water after bypass is measured by sensor 9. Signals from these sensors 8 and 9 are taken (summarize ) using measuring and functional unit 10, which sets the task to controller 7. When acid is metered into natural alkaline water (or alkali in acidic water), which is a buffer solution, the alkalinity of water decreases, while changing alkalinity from 3 ,five mg-eq / L or more to 0.50, 25 mg-eq / L, the pH of the water decreases. With continued dosing of cells and decreasing alkalinity from 0.3 mEq / L to zero, the pH value decreases dramatically, even with an increase in the acidity of water, the pH value slightly decreases (to 0.5 mg mEq / L), and then few. These patterns are repeated at different quality, source water. Option a) Summation of signals from the pH sensor 8 (curve 1, fig. 2) of the acidified water after the mixer to the end of the bypass along the water path and. Sensor 9 pH value curve 2, FIG. 2) the treated water after the bypass 1pH + pH / j) allows to obtain a linear characteristic 3 (Fig. 2) of the total signal, which makes it possible to get the controller unambiguous information about the change in alkalinity in the operating range. Option c) Subtract signals from the pH sensor 8 (curve 1, fig. 3), treated water after the mixer until the end of the bypass along the water and pH sensor 9 (curve 2, fig. 3) treated water after the bypass (pH - pL The differential scheme allows to obtain the characteristic 3 (Fig. 3) with the extremum at the operating point, which allows the regulator to precisely maintain the desired alkalinity of treated water 1; 1. This summation of signals makes it possible to stabilize the range of alkalinity after mixer 2 in the working area of the pH sensors, while the desired alkalinity of the treated water is restored after the bypass. The use of the invention allows an approximate increase in the control accuracy by 1.2-1.4 times. The economic effect from the use of the invention at the KAMAZ CHP in Naberezhnye Chelny will be 49.6 thousand rubles. in year. The invention The method of automatic regulation of the process of acidification of natural water according to ed. St. No. 685628, characterized in that, in order to improve the quality of the treated water by increasing the regulation accuracy, the pH of the treated water is additionally measured behind the bypass, the algebraic sum of the received signal with the pH of the treated water after the mixer until the end of the bypass is found, according to which the ratio costs of natural water and reagent solution in the mixer. Sources of information taken into account in the examination I. USSR author's certificate No. 685628, cl. C 02 B 1/18, 1974. -txi ABOUT X- fut. one pH 12