RU2712908C1 - Device for cleaning surface water from suspended substances and oil-and-oil products - Google Patents

Abstract

FIELD: water treatment plant; ecology.

SUBSTANCE: invention relates to water treatment and can be used for local treatment of storm and melt drains from territories of industrial and motor transport enterprises, filling stations and vehicle servicing stations. Device for treatment of waste water from suspended substances and oil-and-oil products includes housing 1 with filling 2 and drain 3 branch pipes and coarse purification chamber 4, three series-connected units of profiled sheets 8, 9, 10 with input 11, 13, 15, output 12, 14, 16, upper 18 and lower 19 branch pipes. Inlet branch pipe 11 of first unit 8 communicates with coarse filter 4. Outlet branch pipe 12 of first unit 8 communicates with the inlet branch pipe 13 of second unit 9. Outlet branch pipe 14 of second unit 9 communicates with the inlet branch pipe of third block 10. Outlet branch pipe 16 of third unit 10 communicates with drain branch pipe 3. Upper branch pipes 18 of all blocks 8, 9, 10 of profiled sheets are made with possibility of emergent contaminants release. Lower branch pipes 19 of all blocks 8, 9, 10 of profiled sheets are made with possibility of discharge of settling contaminants. Shaped sheets have ledges and recesses. In first 8 and third 10 blocks the profiled sheets are arranged so that their ledges and recesses are directed to the same side; in the ledges the upper holes are made, in the cavities the lower holes are made. In second block 9 shaped sheets are arranged so that their ledges and recesses are directed to opposite sides with formation of channels of variable cross-section. At that, sheets have no holes for discharge of contaminants in projections and recesses forming the narrowest section of channels.

EFFECT: invention increases efficiency of treating waste water from oil and oil products.

1 cl, 4 dwg

Description

The invention relates to the field of wastewater treatment from suspended solids and oil and oil products, in particular, to equipment for local treatment of storm and melt drains from the territories of industrial and motor transport enterprises, gas stations and service stations for cars.

Known installation for the treatment of surface and industrial wastewater (RF patent 79548 for utility model, class C02F 1/40. Installation for wastewater treatment // VN Voznesensky, VA Gontarev, VV Lyadov. LLC “TriVex.” - Announcement on 10/13/2008; No. 2008140177/22; published on January 10, 2009; Bull. No. 1), containing a horizontal cylindrical body, divided by vertical partitions into three communicating chambers; inlet and outlet pipelines. In the first chamber in the direction of the purified water, there is a device for the primary treatment of runoff from coarse suspended solids and large drops of emulsified oil products. In the second chamber (second stage), the profile units of thin-layer sedimentation separators with inclined flat plates are used as cleaning devices. It is indicated that, as an additional fine-cleaning device, the second chamber may contain a coalescence-precipitating element, which is a sheet of oleophilic material with a cellular profiled surface formed by rows of longitudinal and transverse sinusoidal waves, with through holes in the ridges. For deep purification of wastewater in the third chamber of the installation is a removable sorption filter. Each of the installation chambers contains an inspection hatch. The installation is mounted in a single horizontal block of underground or ground execution.

A disadvantage of the known installation is the low water throughput and insufficient efficiency of devices located in the second chamber. The throughput of the plate thin-layer sump is limited by the need to maintain a laminar flow regime in the channels, which forces either to reduce the distance between the plates or to reduce the speed of movement of water passing between them. Excessive reduction of the distance between the plates leads to a fast clogging of the channels with sticking dirt, which reduces the duration of the period of operation of the package of plates without rinsing and regeneration.

In addition, in surface wastewater, oil droplets having a density less than the density of water often form agglomerates with suspended particles of higher density. Such agglomerates have buoyancy close to zero, and it is almost impossible to separate them from water by sedimentation.

The coalescence-precipitating element mentioned in the description of the known installation, which is a single sheet of oleophilic material with a cellular profiled surface formed by rows of longitudinal and transverse sinusoidal waves with through holes in the ridges, cannot significantly increase the efficiency of wastewater treatment in the second chamber. Such sheets can be used, but there should be not one, but several, and they should be arranged in blocks so that the wastewater moves through the channels between the sheets.

Since the efficiency of water purification from emulsified oil products in the second chamber of the installation is not high enough, the adsorption filter located in the third chamber will be overloaded with impurities, the duration of the filter cycle will be small, and the filter will require frequent replacement.

A device for treating wastewater from petroleum products, fats, oils, large and fine contaminants, which is recommended for use in the treatment of wastewater from parking lots, gas stations, industrial enterprises, garages and other objects (utility model patent 115349 of the Russian Federation under class C02F 1 / 4Q. A device for wastewater treatment (options) // GV Mindlin. CJSC “AZS Technologiya.” - Declaration 01.12.2011; No. 20111148776/05; publ. April 27, 2012. Bull. No. 12).

The formula of the known device according to this patent is multivariate.

As an analogue of our design, we consider the device according to paragraphs 5 and 6 of the formula of the specified utility model.

The known device for wastewater treatment contains a housing with bulk and drain nozzles, a rough cleaning chamber at the entrance to the housing and a filter at the outlet of the housing. In addition, the device further comprises a block of profiled oleophobic sheets with inlet, outlet, upper and lower nozzles and a thin-layer deposition unit with an input lower and output upper holes, the input lower opening of the thin-layer deposition unit communicating with the coarse cleaning chamber, the output upper opening of the thin-layer deposition unit communicates with the inlet pipe of a block of profiled oleophobic sheets, the outlet pipe of a block of profiled oleophobic sheets communicates with a filter, the upper pat the side is configured to output pop-up contaminants, the lower pipe is configured to output sedimentary contaminants.

Profiled oleophobic sheets are made with protrusions and depressions, in the protrusions there are upper openings for penetration of pop-up contaminants, lower openings in the depressions for passage of settling contaminants.

The disadvantage of the described device is the low throughput and insufficient efficiency of the thin layer deposition unit. The capacity of the plate thin-layer sump is limited by the need to maintain a laminar flow regime in the channels, which makes it possible to reduce the speed of movement of wastewater passing between them. The resulting agglomerates of suspended particles and petroleum products, having buoyancy close to zero, in the device of gravitational action (thin-layer sedimentation tank) is practically impossible to remove.

In the block of profiled sheets of wavy geometry, the removal of such agglomerates is possible under the action of inertia forces. However, as our studies showed, on the profiled sheets used in the known device, it is impossible to remove drops of oil and oil products with sizes less than 20-30 microns from water. Since the content of droplets with sizes less than indicated in storm sewage is usually about 20 mass. %, the degree of water purification from oil and oil products does not exceed 80%, and the residual concentration of oil products at the outlet of the block of oleophobic shaped plates is quite large.

As a result, the filter or filter adsorber installed in the final cleaning stage will operate under adverse conditions. Frequent replacement of the filter media, which will quickly become contaminated, will be required.

The closest in technical essence to the alleged invention is the device according to paragraphs 3 and 4 of the known utility model (patent for utility model 115349 of the Russian Federation according to class C02F 1/40. Device for wastewater treatment (options) // G.V. Mindlin. “Gas station Technology.” - Declared December 1, 2011; No. 20111148776/05; publ. April 27, 2012. Bull. No. 12).

The known device for wastewater treatment contains a housing with a bulk and drain pipes and a rough cleaning chamber. In addition, the device further comprises at least two consecutively connected blocks of profiled oleophobic sheets with inlet, outlet, upper and lower nozzles, the inlet pipe of the first block communicating with the coarse cleaning chamber, the outlet pipe of the first block communicates with the inlet pipe of the second block, the outlet pipe of the second block communicates with the drain pipe; the upper nozzles of the first and second blocks of profiled oleophobic sheets are configured to exit pop-up contaminants; the lower pipes of the first and second blocks of profiled oleophobic sheets are configured to remove sedimentary contaminants.

Profiled oleophobic sheets are made with protrusions and depressions, upper openings for the passage of pop-up contaminants are made in the protrusions, lower openings for the passage of sedimentary contaminants are made in the depressions.

The disadvantage of this device is the low degree of wastewater treatment from petroleum products. After removal in the first block of profiled sheets of all drops of oil products larger than 20-30 microns, in the second block, completely identical to the first, the water treatment process is repeated under similar hydrodynamic conditions. Small droplets of oil remaining after the first block follow the water flow lines and only in rare cases reach the surface of the plates. The relative velocities of phases and droplets of different sizes are close to zero. In the second block of profiled plates, the process is not effective. In the third - even more so.

The aim of the present invention is to increase the degree of wastewater treatment from oil and oil products.

This goal is achieved by a device for treating wastewater from suspended solids and oil and oil products, including a housing with bulk and drain nozzles and a coarse cleaning chamber, three blocks of profiled sheets connected in series, having input, output, upper and lower nozzles, and the input nozzle of the first block communicates with the coarse cleaning chamber, the outlet pipe of the first block communicates with the inlet of the second unit, the outlet pipe of the second block communicates with the inlet of the third unit, the third outlet unit communicates with the spout; the upper branch pipes of all blocks of profiled sheets are configured to exit pop-up contaminants; the lower branch pipes of all blocks of profiled sheets are configured to remove sediment; the profiled sheets are made with protrusions and depressions, in the first and third blocks, the profiled sheets are arranged so that their protrusions and depressions are directed in the same direction, in the protrusions of the profiled sheets are made upper openings for the passage of pop-up contaminants, lower openings are made in the depressions for passage of settling pollution; and in the second (intermediate) block, the profiled sheets are arranged so that their protrusions and depressions are directed in opposite directions with the formation of channels of variable cross section, while the sheets do not have openings for the exit of contaminants in the protrusions and depressions that form the narrowest part of the channel cross section. The profiled sheets of the first and second block are made of oleophobic material or of a material with an oleophobic coating, and the profiled sheets of the third block are made of oleophilic material.

The installation of an additional second (intermediate) block with a different channel configuration between the first and third blocks of profiled wavy-shaped plates promotes the enlargement of oil product droplets due to dynamic coalescence. In the second (intermediate) block, the profiled sheets, due to the oppositely directed arrangement of the protrusions and depressions, form channels of variable cross section in which the wastewater stream alternately narrows and expands. This contributes to an increase in collision frequency and dynamic coalescence (enlargement) of oil and oil product droplets, which further leads to an increase in the efficiency of their separation from the stream in the third block of profiled sheets.

Our studies showed the presence of a positive effect of moderate turbulization of the wastewater stream on the degree of its purification in the blocks of sinusoidal profile plates. Turbulent vortices contribute to a more frequent contact of droplets both with the surface of the plates and with each other. A particularly good effect at moderate flow rates (up to 30 mm / s) is obtained by the use of plate blocks with channels of an alternately tapering and expanding section. This shape of the channels can be obtained, for example, by alternating profiled plates in the block so that their protrusions and depressions are directed in opposite directions, namely, in pairs towards each other. It is this configuration of channels that an additional (intermediate between the first and third) block of profiled plates should have.

The aggregate stability of diluted emulsions is due to the relatively low concentration of oil product droplets in water, at which the probability of their mutual collision and subsequent coalescence is low. The probability of particle collisions is directly proportional to the square of the numerical concentration. For diluted emulsions with an oil concentration of less than 100 mg / l and an average droplet size of 10 μm, the probability of occurrence is only 0.01. In the second block of profiled plates, when passing through bottlenecks shared by the emulsion (between the protrusions of adjacent profiled plates), dispersed particles (droplets of oil products) in it encounter a much higher probability, due to which they merge and enlarge. When a certain size is reached, coarse droplets under the influence of gravity are separated from the flow in the next block of plates.

The profiled plates (sheets) located in the second unit of the installation should not have openings for the exit of contaminants in the protrusions and depressions that form the narrowest part of the channel cross section, since if there were holes in the narrowest sections, an injection effect could occur suction of wastewater from adjacent channels, leading to undesirable excessive mixing and crushing of drops.

As experiments have shown, the effluent stream emerging from the additional (intermediate) block contains droplets with sizes of 50-100 microns, which are reliably captured in the last block of profiled plates. In addition, since water with a reduced concentration of contaminants comes to the third block, and the probability of clogging of the channels is small, it is proposed to use profiled plates made of oleophilic material in the third block, which increase the efficiency of the cleaning process due to adhesion. As a result, the degree of water purification from emulsified oil and oil products at the outlet of the third block reaches 98-99%.

The proposed scheme of a device for the treatment of storm sewage from suspended solids and oil products is shown in FIG. 1.

A wastewater treatment device comprises a housing 1, a bulk pipe 2, a drain pipe 3, a coarse treatment chamber 4, partitions 5, 6, 7. Between the partitions 5, 6 and 7, the first 8, second 9 and third 10 blocks are connected in series profiled sheets with upper 18 and lower 19 nozzles. The upper nozzles 18 are configured to output pop-up contaminants from the blocks. The lower nozzles 19 are configured to withdraw sedimentary contaminants from the blocks. The inlet pipe 11 of the first block 8 communicates with the camera 4 rough cleaning. The outlet pipe 12 of the first block 8 communicates with the inlet pipe 13 of the second block 9. The outlet pipe 14 of the second block 9 communicates with the inlet pipe 15 of the third block 10. The outlet pipe 16 of the third block 10 communicates with the drain chamber of the purified water 17.

In FIG. 2 shows the relative positioning of the profiled sheets in blocks 8, 9 and 10. In the first (pos. 8) and third (pos. 10) blocks, the profiled sheets are parallel to each other, in the second block (pos. 9) - with alternating profiled plates such so that their protrusions and depressions are directed in opposite directions with the formation of channels of variable cross section, while the sheets do not have openings for the exit of contaminants in the protrusions and depressions that form the narrowest part of the section of the channels.

In the first 8 and second 9 blocks, profiled sheets of oleophobic material (or coated with an oleophobic coating) are installed, in the third block 10, profiled sheets of oleophilic material are installed.

The profiled sheets are made with protrusions 20 and depressions 21. In the protrusions 20 of the profiled sheets are the upper holes 22 for the passage of pop-up contaminants. In the hollows 21 of the profiled sheets, lower holes 22 are made for the passage of settling contaminants.

In FIG. 3 shows the relative position of the protrusions, depressions and holes in the profiled sheets of the first 8 and third 10 blocks.

In FIG. 4 shows the mutual arrangement of the protrusions, troughs and holes in the profiled sheets of the second (intermediate) block 9. In the second block, the profiled sheets do not have openings for the exit of contaminants in the protrusions and troughs, forming the narrowest part of the cross-section of the channels.

The device operates as follows. The purified water flowing out of the coarse cleaning chamber 4 sequentially flows through three blocks 8, 9 and 10 of profiled sheets and, accordingly, goes through three stages of cleaning. Wastewater purified in the first block 8 using parallel mounted profiled oleophobic sheets enters the second block 9 of profiled oleophobic sheets arranged so that their protrusions and depressions are directed in opposite directions with the formation of channels of variable cross section. In block 9, when passing through a bottleneck shared by an emulsion (between the protrusions of adjacent profiled plates), dispersed particles (oil droplets) located in it inevitably collide, due to which they are combined and enlarged. Upon reaching a certain size, coarse droplets under the influence of gravity are separated from the stream in the third block 10 with parallel mounted profiled oleophilic sheets. Oleophilic material contributes to a more intense coalescence of oil and oil products on its surface due to adhesion. Pop-up contaminants are retained under the protrusions 20, coalesce and float to the upper part of the housing 1 through the upper holes 22 and the upper pipe 18. The sediment pollution is trapped in the depressions 21 and settle into the lower part of the housing 1 through the lower holes 22 and the lower pipe 19. Finally, the purified water is drained from the housing 1 through the chamber 17 through the drain pipe 3.

Additional intensive coalescence of oil and oil product droplets in the second block of profiled plates arranged in such a way that they create alternating narrowing and expansion of the emulsion flow allows increasing the degree of water purification in the third (last) block. In addition, the use of profiled sheets of oleophilic material in the last block also contributes to the intensification of the process of coalescence separation of oil and oil products, which allows achieving an overall efficiency of water purification in the installation of at least 98%.

Claims (2)

1. A device for treating wastewater from suspended solids and oil and oil products, including a housing with bulk and drain pipes and a coarse cleaning chamber, three serially connected blocks of profiled sheets having input, output, upper and lower pipes, the input pipe of the first block communicating with a coarse cleaning chamber, the outlet pipe of the first block communicates with the inlet pipe of the second block, the outlet pipe of the second block communicates with the inlet pipe of the third block, the outlet pipe rubs its block is in communication with a drain pipe, the upper pipes of all blocks of profiled sheets are configured to exit pop-up contaminants, the lower pipes of all blocks of profiled sheets are configured to remove sediment, the profiled sheets are made with protrusions and depressions, characterized in that in the first and third blocks the profiled sheets are arranged in such a way that their protrusions and depressions are directed in the same direction, in the protrusions of the profiled sheets there are upper openings for the passage of pop-up contaminants, in the troughs the lower holes are made for the passage of sedimentary contaminants, and in the second (intermediate) block, the profiled sheets are arranged so that their protrusions and troughs are directed in opposite directions with the formation of channels of variable cross section, while the sheets do not have openings for exit contamination in the protrusions and depressions, forming the narrowest part of the cross-section of the channels. 2. The device according to claim 1, characterized in that the profiled sheets of the first and second block are made of oleophobic material or of an material with an oleophobic coating, and the profiled sheets of the third block are made of oleophilic material.

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