SU1539612A1 - Concentration meter of active silt in stagnant water - Google Patents

Abstract

The invention relates to a wastewater treatment technique, in particular, to devices for measuring the concentration of activated sludge in wastewater. The aim of the invention is to improve the measurement accuracy. The device contains a radiation source, two radiation receivers, one of which is included in the measuring channel and the other in the reference one, integrator, recorder, control circuit. The unwanted illumination of the photodetectors is periodically compensated by the integrator during dark time intervals, which are equal in duration to the time intervals during which the source radiation exists. 1 il.

Description

The invention relates to a wastewater treatment technique, in particular, to devices for measuring the concentration of activated sludge in wastewater.

The aim of the invention is to improve the measurement accuracy.

The drawing shows a diagram of the device.

The device contains a pulse generator 1, a LED 2, an inverter 3, the first 4 and second 5 photodiodes, the first light guide 6, the lens 7, protective glasses 8 and 9, the photometric ball 10, the focusing system 11, the second light guide 12, the first 13, the second 14, the third 15, fourth 16 keys, integrator 17, trigger 18, first 19 and second 20 elements 2I, registrar 21..

The output of the pulse generator 1 is connected to the LED 2, the input of the inverter 3, the control input of the third

key 15, the clock input of the trigger 18 and the second input of the first element 2I 19, and the output of the inverter 3 is connected to the control input of the fourth key 16 and the second input of the second element 2I 20. The outputs of the first 19 and second 20 elements 2I are connected to the control inputs of the second 14 and the first 13 keys, respectively, and the output of the second element 2И 20, in addition, is connected to the input of the recorder 21. The first 13, second 14, third 15, fourth 16 keys are connected between the first 4 and second 5 photodiodes and the integrator 17, whose output connected to the information input trigger pa 18, and the output of flip-flop 18 is connected to first inputs of first 19 and second 20 elements 2I. LED 2 is optically coupled to the first photodiode 4 directly, and to the second photodiode 5 sd

with

with

YU

through a measuring channel consisting of a first light guide 6, a lens 7, protective glasses 8 and 9, a photometric ball 10, a focusing system 11 and a second light guide 12.

The device works as follows. .

The pulse generator 1 generates pulses with a duty cycle of 2 (square wave), which periodically illuminates the LED 2. At the moment of ignition of the LED 2, a third key 15 opens and the photocurrent of negative polarity from the second photodiode 5 goes to the integrator 17. Photocurrent value equals

1FZ (P3 K g L + Fpost 1) j,

where f is the luminous flux of the led 2; K2 - transfer coefficient measured

telnogo channel:

i is the transmittance of the medium containing activated sludge; , 1 - extraneous illumination falling on the photodiode 5; K, - conversion factor

F32

photodiode 5.

Kfo, - conversion factor of the photodiode 4.

When LED 2 goes out, the first key 13 opens and the integrator receives a photocurrent I $ l - (posg, l), and the charge Q accumulated on the integrator 17 due to the photocurrent of the first photodiode 4 will be equal to

Q (1f4 + 1,), -K,

T 2

The coefficients K1 and K2 are set such that the photocurrent of the first photodiode 4 is greater than the photocurrent of the second photodiode 5, so the voltage at the output of the integrator 17 will decrease.

During cyclic operation of the device, the charges caused by the photocurrent of the first 4 and second 5 photodiodes are balanced, i.e. For every n pulses of the photocurrent, from the second photodiode 5, m balancing pulses of the photocurrent are received from the first photodiode 4.

nQ + nQ 0;

When the LED goes out, the fourth key 16 is turned on, and the photocurrent supplied to the integrator is 1f4, equal to

Q (1f Fcost 2, Cfd j) "

During all this time, a charge Q, equal to

d oce + 1f +). T / 2,

where T is the oscillation period of the generator

1 pulses

which does not depend on extraneous for the lights, but the voltage at the integrator output will increase. If this voltage reaches the trigger level of trigger 18, then along the front of the next pulse from generator 1 it also triggers the first inputs of the first 19 and second 20 elements 2I. unit. During ignition of the LED 2, the second capacitor 14 opens and the integrator 17 begins to receive a photocurrent of positive polarity from the first photodiode 4 with a value equal to

1 Ф1 (ФК, + фпосТ,) - К, 9,, where К1 is the optical coupling coefficient between the LED 2 and the diode 4;

Fpost1 stray light photodiode 4;

where K is the proportionality coefficient.

TO

K K, K f i

The relationship is

pulse frequency f at the outputs of the first 19 and second 20 elements 2И, which is fed to the recorder 21; f K-Ј.

During calibration, € 1 and.

When analyzing wastewater containing activated sludge, the pulse frequency f at the input of the recorder will be related to some functional dependence on the concentration of activated sludge C and frequency during calibration:

 f U (C, fk).

From this ratio, the logger determines the concentration of activated sludge in the wastewater.

The invention allows to reduce the error due to extraneous flare and extend the measurement range towards higher concentrations of activated sludge.

five . 15

Claims (1)

Invention Formula An activated sludge concentration meter in wastewater containing a light diode connected to a pulse generator, optically coupled to the first photodiode directly and to the second photodiode through a measuring channel containing a first light guide, a lens, two protective glasses arranged along the radiation path, a photometric ball focusing system and a second light guide, as well as a recorder, characterized in that, in order to improve the measurement accuracy, an integrator, a trigger, an inverter, two 2I elements and four keys are additionally introduced into it, ohm connected to the input of the integrator through the first and second key126 The outputs of the first photodiode, and through the third and fourth keys - the outputs of the second photodiode, respectively, the integrator output is connected to the trigger information input, the output of which is connected to the first inputs of the 2I elements, the output of the first element 2I is connected to the control input of the second key, and the output of the second element 2I — with the recorder input and the control input of the first key, the output of the pulse generator is connected to the input of the inverter, the control input of the third key, the trigger input of the trigger and the second input of the first element 2I, and the output and vertora coupled to the control input of the fourth switch and the second input of the second element 2I.