SU1500625A1 - Waste water purifying apparatus - Google Patents

Description

The invention relates to devices for flotation wastewater treatment and can be used in wastewater treatment schemes of oil refining. Petrochemical and chemical enterprises. The aim of the invention is to improve the efficiency of treatment of contaminated water by improving the structure of the flow in the flotation chamber and eliminate the possibility of removal of air from the structure. Wastewater treatment unit contains

2

tangential feed line

float chamber with agitator,

aerated water dispenser with

ring block thin layer hori.1

horizontal plates, flotation chamber.

Annular thin-layer inclined blocks of countercurrent flotation and countercurrent sedimentation are installed in the flotation chamber, installed with a gap relative to each other to form a filtering zone in the suspended sediment layer, a scraper mechanism with an upper scraper and a drive, a foam collection tray, a pit for discharge of sediment, with This ratio of the volume of chambers, zones and blocks in d

the device to the volume of the device is: flocking chamber 0,13-0,38; distributor of aerated water with an annular block of thin-layer horizontal plates 0.01-0.03; flotation chamber 0,590,86; annular thin-layer block countercurrent flotation of 0.09-0.14; annular thin layer block of countercurrent sedimentation 0.04-0.06 ', filtering zone in the suspended sediment layer 0.17-0.28. The design of the device provides improved flow structure, prevention. removal of air from the facility, thereby increasing the efficiency of wastewater treatment. 2 Il.

The invention 'relates to devices for the treatment of petrochemical, chemical and petroleum wastewaters Ц „1500625 A1

manufacturing plants

fertilizers, engineering plants ·

Dov, construction industry facilities, etc.

1500625

from petroleum products and mechanical impurities contained in them.

The aim of the invention is to increase the cleaning efficiency by improving the flotation process. ^one

Figure 1 shows the proposed device, a longitudinal section; figure 2 - node 1 in figure 1.

The device contains a tangential 10 supply pipe 1, the camera 2 ·

flocculation with stirrer 3, flotation chamber 4, separated from the flocculation chamber by a partition 5.

At the bottom of the flotation chamber around the perimeter: partitions 5: there is an aerated water distributor, 'including annular pipe 6 with nozzles, and a differentiated block of thin-layer horizontal plates 7 placed directly behind this pipe with nozzles, while the length of thin-layer horizontal plates 7 in the block increases sequentially top down*

In the flotation chamber 4, thin-layer inclined blocks 8 and 9 of counter-flow flotation and counter-current settling are installed, respectively, installed with a gap between each other and the formation of a zone 10 of gravitational flocculation. The device contains a scraper mechanism with an upper scraper 11, a lower scraper 12 and a drive 13, a tray 14 for collecting foam, a pit 15 for collecting and sludge,

The ratio of the volumes of chambers, zones and blocks in the device to the volume of the device is:

Float chamber

Aerated water distributor with a differentiated block of thin-layer horizontal plates

Flotation chamber Thin layer block of countercurrent settling Thin layer block of countercurrent flotation

Gravitational flocculation zone

15

20

25

thirty

35

40

0.13-0.38

45

0.01-0.03

0.59-0.86

50

0.17-0.28

55

The device works in a manner.

0.09-0.14

0.04-0.06

as follows

Waste water containing the reagent flows at a speed of 1.5-2.0 m / s via pipeline 1 to the lower part of chamber 2 flocculation. The mixer 3, the lower ends of the blades of which are located above the sewage inlet, rotates in the opposite direction of the circular flow, thereby creating a mode of mixing the sewage with an increased velocity gradient. When moving wastewater from the bottom up, there is a gradual alignment of speeds

I,

and conditions are created for optimal (slow) flocculation.

Next, coagulated water flows from the chamber 1 flocculation in the direction of the chamber 4 flotation under the partition 5 and enters the space of the distributor of aerated water located in the lower part of the flotation chamber (see Fig.2). Displacement of coagulated water with aerated water discharged from the ring pipe 6 with nozzles occurs in the initial part of the distributor above the ring pipe with nozzles at the expense of the counter-current direction of the flow of coagulated water (from top to bottom) and aerated water (bottom ¹ up). Further, the flow of a mixture of coagulated and aerated water acquires a predominantly horizontal direction of movement and enters the space of a differentiated block of thin-layer horizontal plates 7.

The flow of aerated water leaving the pipe b with nozzles, as well as the flow of a mixture of coagulated and aerated water at the beginning of the distributor of aerated water to a differentiated block of thin-layer horizontal plates 7 contains air bubbles of various sizes.

Two forces act on the air bubbles in the volume of the distributor - the lifting force directed upwards and the hydraulic force of the flow of coagulated water directed horizontally towards the differentiated unit. The combined effect of these forces air bubbles upwardly perform angular motions in the ^x direction zheniya differential unit, thus there is differential separation bubbles

500625

in size. The distribution of bubbles along the tiers of a differentiated block is as follows: the larger the bubble size (i.e., the greater its lift), the higher the tier of the differentiated block it falls into. Thus, for each tier of a differentiated block, the presence of bubbles - air of the same size and strictly defined for this tier is characteristic. The discharge from the differentiated block into the flotation chamber of streams of purified water containing air bubbles of certain divided sizes is such that, due to the increasing from top to bottom length of thin-layer, horizontal plates in the block along the length of the flotation chamber from its initial part towards its peripheral part (i.e., in the direction from the distributor of aerated water to the thin-layer block 8 of countercurrent flotation), streams containing air bubbles of decreasing size a.'Za thereby flotation chamber are series-arranged ravnopuzyrchatoy flotation zone, in koto- 30 ryh proiskhodit.effektivnoe chdstits extracting contaminants.

 The flow of a mixture of aerated and coagulated water, created by the lower part of the differentiated unit, continuously flushes the sediment containing a significant amount of hydrolyzed coagulant from the bottom of the flotation chamber 4 to form aero floccules of air bubbles and particles dd. Repeated return of sediment to the process allows to reduce the initial dose of the reagent.

In the Flotation cell 4, the bulk of the contaminants are removed. In the flotation chamber 4, the general direction of the fluid is ascending-radial; when approaching the thin-layer oblique block 8, the direction changes to a descending-radial direction; at this turn, larger bubbles are released, which float to the surface of the liquid to be cleaned before the thin-layer oblique block 8, from the small , which are carried by the flow of water into the space of the thin-layer inclined block 8. In block 8, countercurrent flotation due to the effect of inhibition of pop-up

45

50

Air bubbles of a moving fluid increase their residence time in water, and, accordingly, the air-1 collision rate with removed contaminants. The microbubbles of air carried by the liquid from the countercurrent flotation unit 8 under the conditions of the laminar movement of the fluid in block 9 and zone 10 are stable in size and are in contact with equivalent particles by solid particles. Size ratio h ^br particles and bubbles close to unity, ^r 'that is most effective for the flotation process.

Blocks 8 and 9 provide intensive coalescence and the floating of air bubbles in the peripheral part of the structure on the surfaces of the inclined plates of the blocks, which eliminates the removal of air bubbles into the purified water and increases the cleaning efficiency.

In blocks 8 and 9, respectively, of countercurrent flotation and countercurrent sedimentation, precipitation and agglomeration in the form of sediment of the non-flooded hydrophilic part of wastewater contamination also occurs. Sediment particles slide from the inclined plates of blocks 8 and 9 and enter zone 10, where they are deposited in the direction of the pit 15. As the purified water containing fine particles of the remaining suspended substances flows through zone 10 in the horizontal direction, contact flocculation occurs — a collision , agglomeration and intensification of sedimentation of small particles of suspended substances and larger sediment particles from blocks 8 and 9. In general, this process also significantly increases the efficiency of wastewater treatment, especially from fine disperse non-floating hydrophilic part of pollution.

The sediment in the pit-15 is scooped by the bottom scraper 12, and the foam product is continuously scrubbed by the top scraper 11 to the collection pan 14. The top 11 and bottom 12 scraper are driven by the drive 13.

The optimum ratio of the volumes of the flooding chamber, aerated water distributor with a differentiated block of thin-layer horizontal plates, flotation chambers with thin-layer blocks of counter-current flotation and settling, zone

7

1500625

eight

gravitational flocculation in the device creates a single process of wastewater treatment, consisting of optimally interconnected stages. The ratio of the volumes of these stages (that is, the ratio of their duration) is determined by the quality of the water being purified, the physicochemical properties of the contaminants, and the degree of their extraction. Thus, flocculation chamber 2 with a relative volume of 0.13–0.38 provides effective reagent flocculation of wastewater pollution with the creation of flocculent particles of a given optimal structure. The decrease in the volume of the flocculation chamber below the specified range 'causes the flocculation process to be incomplete, in 20

coagulated water will have a high content of medicinal particles difficult to extract by flotation and settling,

An increase in the relative volume / flotation chamber over the optimum range leads to unproductive energy consumption on the mixer, the destruction of large flakes, a decrease in the efficiency of flocculation, as well as a general decrease in the cleaning efficiency, including by reducing the relative volume of the flotation chamber. below the optimal range, i.e. due to the lack of duration of the flotation stage coagulated water.

The implementation of the proposed invention of the distributor of aerated water with a differentiated block of thin-layer horizontal plates with a relative volume of 0.01-0.03 provides effective mixing of coagulated and aerated water, differentiated separation of air bubbles in size, distribution of equally bubble flows along the length of the flotation chamber, creating flow that flushes 'sediment from the bottom of the flotation chamber. A decrease in this volume (ie, a decrease in the mixing time) is a challenge. An unacceptable increase in the flow rates of coagulated and aerated water leads to the destruction of flocculating floc flakes and the creation of turbulent jets in the flotation chamber, which sharply reduces the cleaning efficiency. When the volume of the distributor is overestimated, the flow rates go down;

bath and aerated water, which leads to insufficient degree of mixing, inefficient capture of flakes of pollution by air bubbles and reduce the efficiency of flotation.

In the flotation chamber 4, the relative volume of which is 0.590.86, an effective flotation release in the form of foam of aeroflocules of the hydrophobic part of the impurities and sedimentation of the hydrophilic part in the form of sediment and wastewater contamination. Decrease in the volume of the flotation chamber blocks 8 nroty-. flotation and 9 countercurrent sedimentation, zone 10 of gravitational flocculation causes, due to an increase in flow rates of treated water and increased turbulence in the tiers of thin-layer blocks, increased outflow, nose from the contamination device (in this case, small air bubbles with fixed on them, the particle - ·: mi of pollution This effect (although this results in the complete release of air bubbles), since the short duration of flocculation, as was shown above, does not allow for an effective process of wastewater treatment in the structure as a whole.

In a thin-layer inclined block 8 of countercurrent flotation, the relative volume of which is 0.090.14, air bubbles are released with particles of dirt attached to them. As a result of the reduction of this volume, air bubbles do not have time to stand out from the liquid being cleaned, which leads to the removal of air bubbles and pollution from the structure.

In the thin-layer inclined block 9 of countercurrent sedimentation with a relative volume of 0.17-0.28, impurities that remain in the water being purified after the · are precipitated. the passage of all stages of purification in this structure. With a decrease in the thin layer oblique block of countercurrent sedimentation, the residence time of the liquid decreases and

9

1500625

1 o

there is an incomplete separation of all parts of the pollution, which leads to a deterioration in the quality of water purification.

Through the zone of gravitational flocculation 10 with a relative volume of 0.040.06, the purified water containing fine particles of suspended substances flows, as a result of the contact flocculation process there is a collision, agglomeration and intensification of sedimentation of small suspended particles and larger sediment particles from blocks 8 and 9. With a decrease in volume The zone of gravitational flocculation. The process of contact flocculation does not have time to pass completely and the pollution is carried out.

In the flotation chamber 4, in front of thin- layer inclined blocks, larger air bubbles are separated, which float to the surface of the treated water in front of thin-layer inclined blocks, from. smaller air bubbles that flow into the space of a thin layer inclined block of countercurrent flotation, and an increase in the volume of blocks 8 of countercurrent flotation 9 of countercurrent sedimentation and a zone of gravitational flocculation leads to a decrease in space in front of thin layer inclined blocks, resulting in streams of treated water coming from the differentiated block and containing air bubbles of a certain size, do not have time to be distributed along the length of the flotation chamber in the direction away from I aerated water to thin-layer inclined unit 8 countercurrent flotation. Therefore, consistently located equal-bubble flotation zones are not created in the flotation chamber; the flotation process is carried out with a mixture of air bubbles of different sizes, which reduces the flotation efficiency.

Using the proposed device with the ratio of the volumes of chambers, blocks and zones in the optimal range, the cleaning efficiency from oil products averages 8286Ζ, from suspended substances - 81-84Ζ.

Claims (1)

Claim YU A device for wastewater treatment, including a supply pipeline, flocculation and flotation chambers, aerated water distributor in 15 as a pipeline with nozzles, located in the lower part of the flotation chamber along the perimeter of the partition dividing the flocculation and flotation chambers, characterized in 20 that, in order to increase the cleaning efficiency by improving the flotation process, it is equipped with thin-layer g ”located in the flotation chamber in front of the aerated water distributor 25 block in the form of horizontal plates, the length of which increases from top to bottom, placed on the periphery of the flotation chamber with thin-layer inclined blocks of countercurrent flotation 30 and countercurrent sedimentation, established with a gap relative to each other with the formation of a zone of gravitational flocculation, the ratio of the volumes of chambers, zones and blocks __ in the device to the volume of the device is Chamber flocculation 0,13-0,38 Aerated Water Dispenser with unit horizontal plates 0.01-0.03 flotation chamber 0.59-0.86 40 45 Thin layer block countercurrent flotation 0.09-0.14 Thin layer block countercurrent sedimentation 0.17-0.28 Gravity flocculation zone 0.04-0.06 1500625