SU1493291A1 - Method of controlling filter - Google Patents

Abstract

The invention relates to methods for controlling the operation of filters and can be used to purify wastewater by filtration. The use of the invention will allow to increase the filter performance by improving the quality of control. The method involves switching the filter from the purification stage to regeneration with respect to the differential pressure and the quality of the purified water and termination of the regeneration when the quality indicator of the wash water reaches a predetermined value. When the quality indicator of the wash water reaches a predetermined value, a sample of the filter charge is taken, the concentration of residual organic pollutants in it is determined, compared to the set value and, if the value is higher than the set value, the granular load is additionally treated with an oxidant and then washed. A sample of filter loading is taken through 100-150 filter cycles. 2 tab., 1 Il.

Description

The invention relates to methods for controlling the operation of filters with a granular load and can be used in wastewater treatment.

The aim of the invention is to increase the filter capacity.

The drawing is a schematic diagram of the control system.

A method for controlling the operation of the filter is implemented as follows.

Initial wastewater flows through the inlet pipe 1, the regulating valve 2 passes, enters the distribution system 3, passes through supporting gravel

layers 4 in the lower part of the filter 5, granular loading 6 and drained by chutes 7 into side pocket 8. Next, the filtrate enters pipe 9, on which the shut-off valve 10 and turbidity analyzer 11 are located. Differential meter 12 is set to measure the pressure drop across the filter 5. When the quality of the purified water in the filtering process deteriorates and reaches a predetermined value, and the pressure differential reaches a limiting value, which indicates a depletion of the granular load 6, the output signals from the turbidity analyzer 11 and differential

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meter 12 enters the command decision making unit 13, which supplies signals for switching the filter 5 from the purification stage to regeneration. The signals to the shut-off valve 10 and the control valve 2 overlap the inlet pipe 1 and the filter drain pipe 9 opens the valve 15 to house the granular charging 6 with the washing water. After reaching the required wash water level, the analyzer 18 comes to a signal at the house stage. in block 13, which feeds a coma on the closing of valves 15 and 14 and from control valve 2 and filling

rata. Next, the command generation unit 13 Q valve 10 for switching

filter 5 from the stage of regeneration n cleaning mode.

The decision making control signals to the shut-off valves 14 and 15 for opening the pipes 16 and 17 for discharging and supplying wash water. During the regeneration process, the quality of the wash water at the outlet of the filter 5 is recorded continuously by an analyzer 18 installed on the flush water removal pipe 16. After the industrial water quality indicator reaches a value equal to the industrial water quality indicator, the command decision making unit 13 generates commands to close the shut-off valves 15 and 14 and open the control valve 2 and the shut-off valve 10 to switch the filter 5 from the regeneration stage to the cleaning.

After 100-150 filtercars, before switching the filter 5 to the purification after the required quality of the wash water is reached during the regeneration process, the sampler 19 takes a sample of the granular load 6. In parallel with the filter 5 operation in the cleaning mode, the automatic analyzer 20 determines the concentration of residual organic matter for 30 minutes in the sample, compares it

sends a signal for the subsequent filter cycle to the command decision making unit 13. The control signals for switching the filter 5 from purification to regeneration and its termination are carried out in the sequence described by Bbmie, after which the unit 13, after the end of the washing, gives the command to process the granular charge 6 with an oxidizing agent followed by washing. To do this, after the termination of regeneration by the signals of the unit 13, the valve 15 is closed and the shut-off valve 21 installed in the oxidizer supply line 22 is opened. With the end of the processing mode of the filter 5 with the oxidant, the signal of the unit 13 closes the valve 21

and a valve 15 is opened for washing the washing water with granular feed 6. After the required quality of washing water has been reached at the washing stage, the signal from the analyzer 18 enters unit 13, which commands the closing of valves 15 and 14 and the opening of the control valve 2 and the lock OJ o valve 10 to switch

filter 5 from the regeneration stage to the cleaning mode.

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Example 1, Biologically purified waste water after secondary clarifiers with a suspended matter content of 15 mg / l and the concentration of organic compounds for chemical oxygen demand (COD) 48 is filtered through a filter with a granular load of quartz sand with a grain size of 0.8-1.2 mm,

Sewage water is fed through the inlet pipe 1, filtered through granular charge 6, collected by collecting channels 7 into the side pocket 8 and discharged through pipe 9 of the filtrate drainage. Upon reaching the required concentration of suspended solids in the filtrate, equal to 3.5 mg / l, and pressure drop on the granular load, equal to 2.4 m, after 12 h of operation the filter

5 switch from the purification stage to regeneration. The effect on valve switching is performed by block 13 after receiving the corresponding signals from the turbidity analyzer 11 and the differential pressure gauge 12. Wash water with a concentration of suspended substances of 1 mg / l

and COD 10 is fed with an intensity of 15 l / s-m through the pipeline 17, after passing - granular load

6 are collected by the channels 7 and are led through a pipeline 16 for discharging wash water. After 7 minutes after reducing the concentration of suspended solids in the wash water to 1 mg / l, unit 13 commands the switching of filter 5 from the regeneration stage to purification. Starting from the filter cycle 80, after each subsequent rinsing, a loading sample is taken from the filter housing 5 by the sampler 19, and the concentration of residual organic pollutants in the load is measured using an automatic analyzer 20 (liquid titrometer) with a potentiometric determination

the end point of the titration at a given potential value.

The measured concentration is compared with a predetermined one and, when its value exceeds a predetermined value, the granular charge 6 is treated with an oxidizing agent followed by its home.

Data on the accumulation of residual after washing organic pollutants in the filter loading, depending on the number of filter cycles, is given in Table 1.

As follows from the above data, the amount of residual organic pollutants begins to increase after 100-150 filter cycles and reaches 12.0 against a predetermined value of 10, corresponding to the value of the wash water supplied to the filter 5. After 150 filter cycles, despite the high quality of the wash water at the outlet of the filter 5, the concentration of suspended solids is no more than 1 mg / l; the concentration of residual organic pollutants in the load increases 2 or more times, as a result of which the specific capacity of the filter 5 decreases.

Example 2. Biologically purified waste liquid after secondary clarifiers with a suspended matter content of 15 mg / l and a concentration of organic compounds according to HG1K 48 is filtered through a filter with a granular load of quartz sand with a grain size of 0.8-1.2 mm. The operation is controlled in two ways: the first method (prototype) - by switching the filter from the purification stage to regeneration by pressure drop and the quality of purified water and termination of regeneration when the quality of the wash water reaches a predetermined value, by the second method (according to the proposed control method) estimates of accumulated residual organic pollutants. To implement the second method, after washing the 100th filter cycle, in parallel with the filter operation in the cleaning mode during the 101st filter cycle, the automatic analyzer 20 determines the concentration of residual organic pollutants and when it reaches 12 mgO-1 / L, i.e. . higher than specifiedQ

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The value of CLA (10), block 13 switches the filter from the purification stage to regeneration and stopping the flushing leads in the sequence described in Example 1. After that, at the end of the rinse, the block 13 sends a command to process the filtering load 6 with an oxidizer followed by a home. At a signal from unit 13, valve 13 is closed, shut-off valve 21 is opened, and chlorine water containing 150–200 mg / l is supplied through an oxidizer supply line 22. After 7 minutes of processing at the signal of block 13, the supply of oxidant stops, valve 21 closes and valve 15 opens to wash granular charge 6 with washing water. Wash water is supplied with suspended solids concentration of 1 mg / l and COD 10 through pipeline 17. After 3 minutes suspended solids concentrations in the washed water up to 1 mg / l; block 13 gives the command to switch the filter 5 from the regeneration stage to purification.

Comparative data on regeneration methods are given in table. 2

The proposed control method allows to increase the filter capacity from 150.4 to 1 93.6 m / h m, i.e. by 21, 9%.

Claims (1)

Invention Formula The method of controlling the operation of the filter with granular loading by switching the filter from the purification stage to the regeneration stage - by pressure drop and concentration of suspended particles in purified water and termination of the regeneration stage upon reaching the concentration of suspended particles in the washing water of a given value, characterized in that increase the filter capacity, set the number of filter cycles and, when it is reached, take a sample of filter loading i in each of the subsequent filter cycles at the end of the regeneration stage and, determine the concentration of residual organic pollutants in it, compare it with a predetermined amount and, if the concentration value is higher than the predetermined one, the granular load of the filter is additionally treated with an oxidizing agent followed by a small one. Table 1 Filter performance Proposed method The duration of the filter cycle, h Specific filter capacity, m / h.m table 2 Prototype 12.0 192.6 12.0 150.4 . “In P“ O fe in in about in . ".V.VQ O W ,.  with oeo tPCO   in l o “o  ii feV ". "Vfe y" r n i - Ъ о О о о о о о о ооооС 10ooo "" fishing "about