RU2594213C1 - Device for purifying waste waters from oil products - Google Patents

Abstract

FIELD: ecology.

SUBSTANCE: invention relates to treatment of waste water from admixtures of organic substances - oil products, fats, surfactants, as well as mechanical impurities and can be used in motor transport services, railway transport, food and leather-fur industries enterprises. Floatation chamber 8 is made as a cylindrical barrel, in the upper part of which there is tray 9 connected by overflow pipe 10 with tank 11. Reagent is fed from reservoir 12. Inside chamber 8 shell 14 is fixed coaxially on perforated partitions 13, under the lower edge 15 of which there is rigidly installed inclined partition 16 from a highly porous foamed metal with a lyophobic coating forming cavity 17 for collection of sediment and cavity 18 of partially treated water. Pump 3 pressure pipe is connected with ejector 4, the mixing chamber of which is connected to the air supply source and to pipeline 22 for reagent entrainment. Ejector 4 outlet is connected with branch pipe 25 to supply the mixture to shell 14 over horizontal partition 26 rigidly fixed inside it and made of a highly porous metal with a lyophobic coating, above which there is float 27 from a ferromagnetic highly porous metal. On the outer side of shell 14 above supply branch pipe 25 there are annular magnets 28, embraced by magnetic field concentrator 29. Outlet nozzle 19 is connected to additional pump 32, pressure line 33 of which is connected via a pipeline to the filtration system consisting of filter 36 with a coalescing properties, one outlet of which is connected with sorption filter 37, and the other outlet is connected to the inlet of additional ejector 43, from the outlet of which the liquid medium comes to chamber 17 of residue collection above inclined partition 16, on the body of filter 36 annular magnets are installed.

EFFECT: higher quality of purifying contaminated waste waters with simultaneous increase of safety of the plant servicing.

1 cl, 2 dwg, 2 tbl

Description

The invention relates to the field of technology for the treatment of wastewater contaminated with impurities of organic substances, mainly oil products, fats, surfactants, mechanical impurities, and can be used in the auto industry, in the food, leather, fur, pulp and paper industries, as well as for ballast and wastewater treatment for oil, water and rail transport.

An increase in production volumes with an increase in emissions and inevitable waste, while at the same time stricter requirements and standards for environmental protection, urgently necessitates solving the problem of cleaning, regenerating and disposing of working media. Moreover, it can be effluents of both industrial technical and domestic waters with excess of MPC norms, which are forbidden to be discharged without preliminary treatment.

Since the working media used, waste products (waste) are dispersed multiphase systems (media), the development of technical means for their separation is an urgent task.

A device for treating wastewater from oil products, containing a sewage pipe connected to a suction well that feeds through a suction pipe with a filter a centrifugal pump, has an ejector on the suction pipe, connected to a pipe with atmospheric air, and the discharge pipe of this pump is connected to a saturator for dissolving the air introduced into the water, the outlet pipe of the saturator is connected to an open flotation chamber equipped with a scraper mechanism and a foam collector to remove the pop-up foam of particles to be flotated and bottom discharge of purified water (Karavaev II, Reznik NF Flotation wastewater treatment of washing and steaming stations and depots. - M.: All-Union Publishing and Printing Association of the Ministry of Railways, 1961. - P. 4 -12).

The disadvantage of this device is the relatively long duration of dissolution of air in water and the consequent need for the introduction of a special pressure tank operating under pressure into the wastewater treatment apparatus chain.

A known installation for the purification of oily wastewater, including a receiving well, a feed pump, a pre-treatment unit, a flotation treatment chamber with a foam collector and a scraper mechanism for removing foam, a filter chamber — a sorption filter unit and a water drainage device (RF Patent No. 2079437) , C02F 1/40, 1997).

However, this installation does not provide effective wastewater treatment, since it does not remove dissolved oil products.

A device for cleaning wastewater from oil products, containing a sewage pipe connected to a suction well supplying a transfer pump through a suction pipe, the pressure pipe of which is connected to an ejector, a pump and a saturator, an open flotation chamber equipped with a scraper mechanism and a foam collector for removing pop-up foam floated particles and bottom discharge of purified water (RF Patent No. 2155716, C02F 1/24, 1998).

However, due to the possibility of water hammering and “airing” of pipelines, as well as the need to coordinate the operation of the transfer pump and the saturator pump, the reliability of the entire device as a whole can be significantly reduced.

The closest in technical essence and taken as a prototype is a flotation-filtration unit containing a drive, a suction pipe, a pump unit, an ejector, a flotation chamber with a scraper mechanism, a tray, an overflow pipe and a filtration system, while the ejector has two nozzles, one of which serves to inject a reagent solution, and the other - for suction of atmospheric air (RF Patent No. 2543735, C02F 1/24, 2006).

However, this installation does not provide for the removal of dissolved oil products, and the high working pressures of 0.5-5.5 MPa, necessary for functioning, tighten the requirements for its reliability and safety.

The technical result of the invention is improving the quality of treatment of contaminated wastewater while improving the safety of maintenance of the installation.

The specified technical result is achieved by the fact that in the known device for wastewater treatment from petroleum products, containing a reservoir with the source medium, connected by a pipeline to the suction pipe of the pump, an ejector with two nozzles, one of which serves to enter the reagent, and the other to suck in atmospheric air , a flotation chamber, in the upper part of which a foam collecting tray is made, connected by an overflow pipe to the reservoir, and a filtration system, according to the invention, the flotation chamber is made in the form of a cylindrical steel ana, inside it a shell is coaxially fixed on perforated baffles, under the lower end of which there is a rigidly inclined baffle made of highly porous cellular metal with a lyophobic coating with a pore size of 30 μm, forming a cavity for collecting sediment and a cavity of partially purified water drained through the outlet pipe, discharge pipe the pump is connected by a pipeline with a crane to an ejector, the mixing chamber of which is connected to an air supply source and to a pipe for reagent suction from the tank, the outlet of the pipeline ejector the odom is connected to the nozzle for feeding the mixture into the shell above the horizontal partition rigidly fixed inside it, made of highly porous cellular metal with a lyophobic coating and a pore size of 30 μm, over which a float of ferromagnetic highly porous metal is placed, ring magnets are installed on the outside of the shell above the nozzle, covered by a magnetic field concentrator to a height not less than the diameter of the shell, an additional centrifugal pump is connected to the outlet pipe through a non-return valve and a tap, the pressure line of which is connected by a pipeline to a filtration system consisting of a filter with coalescing properties, one outlet of which is connected to a sorption filter, and the other outlet through a stopcock and check valve is connected to the inlet of an additional ejector, from the outlet of which the liquid enters the sedimentation cavity above annular flotation chamber, ring magnets are installed on the filter housing with coalescing properties.

In FIG. 1 is a block diagram of a device for treating wastewater from oil products (general sectional view);

FIG. 2 - filter with coalescing properties (section along AA of Fig. 1).

The device comprises a storage device 1 with an initial liquid medium, connected by a pipe 2 to a pump 3, an ejector 4 with a nozzle 5 for introducing a reagent and a nozzle 6 for suction of atmospheric air with a check valve 7, a flotation chamber 8 (made in the form of a cylindrical glass), in the upper part which has a tray 9 connected by an overflow pipe 10 to the reservoir 11. The reagent enters from the tank 12. Inside the chamber 8, a casing 14 is coaxially mounted on the perforated partitions 13, and an inclined partition 16 is rigidly mounted under the lower end 15 thereof of high-porosity porous metal (TU 1733-011-03847211-97) with lyophobic coating with a pore size of 30 .mu.m, forming a cavity 17 for sludge collection cavity 18 and partially purified water discharged through the outlet 19.

The pressure port of the pump 3 through a pipe 20 with a valve 21 is connected to an ejector 4, the mixing chamber of which is connected to a source of atmospheric air through a nozzle 6 and a check valve 7, as well as a pipe 22 with a valve 23 for suction of the reagent from the tank 12. The ejector 4 is output by a pipe 24 connected to the nozzle 25 for feeding the mixture into the shell 14 above the horizontal partition 26 rigidly fixed inside it, made of highly porous cellular metal identical to the material of the inclined partition 16 (TU 1733-011-03847211-97) with a lyophobic coating and size A pore ger of 30 μm, over which a float 27 of a ferromagnetic highly porous metal is placed. On the outside of the shell 14 above the nozzle 25 of the mixture, ring magnets 28 are mounted, covered by a magnetic field concentrator 29 to a height not less than the diameter of the shell 14, which ensures the interaction of the vortex layer of the liquid mixture with magnetic fields. An additional centrifugal pump 32 is connected to the outlet pipe 19 of the flotation chamber 8 through a non-return valve 30 and a crane 31, the pressure line 33 of which is connected by a pipe 34 with a crane 35 to a filtration system consisting of a filter 36 with coalescing properties and a sorption filter 37. One output of the filter 36 with coalescing properties, the pipe 38 with the valve 39 is connected to the sorption filter 37, and the other outlet through the valve 40 by the pipe 41 with the check valve 42 is connected to an additional ejector 43, the output of which is a liquid medium through the valve 44 and the pipe 45 enters the flotation chamber 8 in the cavity 17 of the collection of sediment.

Ring magnets 46 are installed on the filter housing 36 with coalescing properties. The outlet pipe of the sorption filter 37 is equipped with a valve 47 for draining clean water. The pipe 38 for supplying a liquid medium for cleaning on the sorption filter 37 is equipped with a valve 48 for draining the oil concentrate and fur. impurities and sampling. The float 27 is made of ferromagnetic highly porous cellular metal according to TU 1733-011-03847211-97. The air suction nozzle of the additional ejector 43 has a valve 49 and a check valve 50 to prevent leakage of liquid medium when the auxiliary pump 32 is turned off. The cavity 17 for collecting sediment of the flotation chamber 8 at the bottom is equipped with a nozzle with a drain valve 51.

Cartridges 52 of filter 36 with coalescing properties (Fig. 2) are made of a polymer of a spatially globular structure (ASG-polymer) and reinforced with foam metal 53 with ferromagnetic properties (TU 1733-011-03847211-97). In the gap 54, spiral guides 55 are installed between the inner surface of the filter housing 36 and the foam metal 53 to swirl the flow in order to increase the exposure time in a magnetic field when filtering a medium with microcontaminations. So, if the exposure time of a small volume of medium at a flow rate V and a helix pitch L is L / V, then when the flow swirls, the path covered by the selected volume will be significantly longer, namely, L / sin b, and the time L / (sin bV), where b is the helix elevation angle (Soviet Encyclopedic Dictionary. - M.: Soviet Encyclopedia. 1989. - P. 224). The sorption filter 37 is also made of ASG polymer.

To remove droplets of oil products from the liquid to be cleaned, porous partitions 16, 26 with lyophobic properties are used. In this case, metal grids made of non-ferrous metal with a fluoroplastic coating are used, manufactured by Elion-2 LLC for filter separation walls (Product Catalog. Filters and filter elements for cleaning aviation fuel. - M.: 2009 - SP). At the same time, the creation of a special relief, as, for example, when using highly porous cellular metals from a copper-nickel alloy coated with a fluorine polymer, provides the appearance of superleophobic properties on dividing surfaces. This is achieved due to the fact that under a drop of liquid on the surface there are tiny air pockets that prevent spreading. Superleophobicity is characteristic of materials with a sharp change in surface curvature. For such structures, contact wetting angles of more than 150 degrees were obtained. (Journal of the Russian Chemical Society named after DI Mendeleev, 2008, vol. LII, No. 3, pp. 60-62). The inclined porous septum 16 does not allow particles of petroleum products larger than the characteristic pore cell sizes of 30 μm.

The magnetic field concentrator 29 (made in accordance with TU 4859-001-4682222-2001) converts background magnetic fields of a vortex nature into a directed energy flow of 0.06 A / m and a frequency of 0.8 MHz (the indicated values of the magnetic field and frequency are due to its design and do not vary).

The use of iron hematite magnetic nanoparticles in a liquid medium as a reagent for the treatment of wastewater contaminated with oil products is explained by the fact that the emulsion droplet shells are characterized by increased adsorption capacity in the presence of ferromagnetic particles. In this case, emulsion droplets of oil acquire a magnetic moment in an external magnetic field and can be separated from water (Batkin I.S., Smirnov Yu.G. Modeling the effects of super-magnetic particles on field emulsions. // Physical and mathematical modeling of systems: Materials VII International Seminar, Voronezh, November 26-27, 2010, Voronezh: VSTU, 2011, part 2 - P. 155-162.). Therefore, iron oxides used as a reagent and a carrier of nanoparticles, supplied from the tank 12 when ejected by a stream of liquid medium into the mixing chamber of the ejector 4, while supplying air provide the formation of an emulsion medium with the above properties.

The creation of an alternating magnetic field using the assembly of permanent ring magnets 28, when applying a high-frequency magnetic field from the hub 29 intensifies the separation processes (A. A. Revina, S. A. Busev, V. G. Kalashnikov, V. G. Lebedev. Spectrophotometric studies the effect of background radiation on reverse micellar solutions of the natural antioxidant flavonoid, quercetin. Electromagnetic waves and electronic systems, No. 8, 2012, v. 17. - S. 63-66). The possibility of using magnetic treatment for the destruction of oil-water emulsions is determined by the fact that under the influence of a magnetic field the shape of colloidal particles changes due to the presence of a double electric layer, and anisotropy of diffusion and viscosity of the water itself also arise. At the same time, the coagulation of oil particles and particles is intensified. Thus, during magnetic treatment of oily water in a magnetic field with a magnetic induction of up to 200 mT and a treatment time of up to 10 s, intense coagulation of oil and metal particles occurs. The oil is collected in the form of large globules (average size up to 150 microns). (Lesin V.I. The physicochemical mechanism of the destruction of water-oil emulsions under the influence of a magnetic field // Materials of the VII All-Russian Symposium "Actual Problems of Adsorption Theory, Surface Modification and Separation of Substances", Department of General and Technical Chemistry of the Russian Academy of Sciences, April 22-26, 2002 - M .: Klyazma. - S. 102).

The presence of a fixed porous septum 26 contributes to the creation of a stable swirling vortex with a discharge in its center and pressure along the periphery, which leads to effective foaming and separation of “trapped” droplets of oil products and pollution particles with air bubbles. (A.P. Merkulov. The vortex effect and its application in technology. - M.: 1966. - P. 70). Taking into account that in the lower part of the vortex, intensive braking of the liquid medium saturated with air occurs, leading to cavitation of the dissolved air with the formation of a large volume of fine bubbles, which leads to the removal of most microfractions of oil products and their oxidation.

Ring magnets 46 mounted on the filter housing 36 with coalescing properties increase the coagulation of oil droplets.

The placement of the float 27 of ferromagnetic highly porous metal above the partition 26 can significantly increase the magnetic field by the magnitude of the magnetic permeability (N.I. Koshkin, M.G. Shirkevich. Handbook of elementary physics. - M .: Nauka, 1975 - P. 160 -163).

A device for treating wastewater from petroleum products works as follows.

The technological process of cleaning can be represented in the form of the following stages:

I. Purification of the liquid medium during the operation of the device (the duration of the stage is determined by the decrease in productivity, when it is reduced by 15%, the regeneration stages are carried out);

II. Regeneration of the sediment collecting cavity 17 (stage duration 10 min);

III. Regeneration of the sorption filter 37 (stage duration 15 minutes).

For the convenience of describing the operation of the device, the position of the stopcocks characteristic for each stage is given in table 1.

At stage I - purification of the liquid medium during the operation of the device, the liquid medium from the accumulator 1 through the pipe 2 by the pump 3 with the open valve 21 through the ejector 4 is tangentially fed into the shell 14 of the flotation chamber 8, with the open valve 23 of the reagent suction from the tank 12 through the pipe 22. The vortex water-air layer is subjected to intense magnetic processing, which is ensured by the action of superimposed variable fields from ring magnets 28 with a low-frequency component and a high-frequency component from the magnetic field concentrator 29, and t Also induced fields arising from the rotation of the float 27 from a highly porous magnetic cellular metal and ferromagnetic twisted reagent nanoparticles. The medium is effectively dispersed during cavitation and through the porous partition 26 from the foam metal enters the lower part of the volume of the flotation chamber 8, and the sludge with petroleum products floats and accumulates in the tray 9. The aqueous dispersed medium with small colloidal particles is collected in the cavity for collecting sediment 17, passes through the lyophobic the inclined porous septum 16 fills the cavity 18 for partially purified water, from where, through the outlet pipe 19, a check valve 30 and an open valve 31 are fed to the input of an additional centrifugal pump 32 and further into the filtration system - filters 36 and 37 with open taps 35, 39, 40, 44, 47 and closed taps 48, 49, 51. At the same time, on filter 36 with coalescing properties, the coagulated particles are continuously discharged through the ejector 43 with closed tap 49 into the cavity 17 of the collection of sediment of the flotation chamber 8. Coagulation is enhanced by the action of assemblies of ring magnets 46. The liquid medium from the filter 36 with coalescing properties is purified from dissolved oil products on a sorption filter 37 made of ASG-polymer. When reducing the productivity of the device during the cleaning of the medium by 15-18%, the cavity 17 of the sediment collection is regenerated and the sorption filter 37 is regenerated, that is, stages II and III, respectively.

At stage II - the regeneration of the cavity 17 of the collection of sediment (carried out with open cranes 21, 23, 31, 35, 40, 44, 49, 51 and closed cranes 39, 47, 48) the entire flow of liquid enters from the centrifugal pump 32 to an additional ejector 43 through pipelines 34 and 41. In the mixing chamber of the ejector 43 with the tap 49 open, the liquid medium is also effectively dispersed and a water-air medium enters through the tap 44 and the nozzle 45, which well removes contaminants from the surface of the inclined partition 16, which are connected with the liquid flow through the pipeline through open crane 51 m They can be washed off and subsequently disposed of in special containers or discharged into settling tanks for industrial waters.

At stage III - regeneration of the sorption filter 37, taps 21, 23, 31, 35, 40, 44, 47, 48 are open, and taps 39, 49 and 51 are closed. The back and direct washing is carried out in a known manner - when connecting a pump with a tank for washing liquid (not shown in Fig. 1) to the nozzles with taps 47 and 48.

Example.

To verify the effectiveness of the proposed device was subjected to wastewater treatment in a volume of 50 l after cleaning tanks for oil products. The performance assessment of the flotation chamber 8, as well as filters 36 with coalescing properties and sorption filter 37 was carried out during sampling after the above elements with the measurement of the content of oil products and mechanical impurities, and the impact of magnetic components (magnet assemblies 46 on the filter 36 and 28 on the shell 14 was evaluated with a magnetic field concentrator 29, as well as a ferromagnetic float 27 and magnetic hematite nanoparticles when supplied from the reservoir 12) for separation efficiency. The initial oil content at the entrance to the developed device was 37.4 mg / l, the content of solids 215 mg / l. For analysis, a Fluorat-02 fluid analyzer was used. The content of solids was determined using the "Automatic tuobidimeter for water TV-346." The measurement results are presented in table No. 2.

An analysis of the results (No. 1 - taking into account the action of magnetic components and No. 2 - without taking into account their action) shows that the presence of magnetic components significantly affects the separation efficiency of both oil products and mechanical impurities. After a small dilution of effluents to a concentration of 0.030 mg / l, they can be "discharged" into open water bodies.

Thus, the use of multi-stage wastewater treatment from oil products during the separation of the main part of emulsified pollutants in a flotation chamber and subsequent separation on filters made of ASG-polymer with coalescing and sorbing properties, while magnetically treating a water-air dispersed medium, allows wastewater to be treated to the level of regulatory requirements.

Claims (1)

A device for treating wastewater from petroleum products, containing a drive with a source medium, connected by a pipeline to the suction port of the pump, an ejector with two fittings, one of which serves to inject a reagent solution, and the other to suck in atmospheric air, a flotation chamber, in the upper part of which a tray for collecting foam is made, connected by an overflow pipe to the tank, and a filtration system, characterized in that the flotation chamber is made in the form of a cylindrical glass, inside it is mounted on perforated walls kach shell, under the lower end of which an inclined partition made of highly porous cellular metal with a lyophobic coating with a pore size of 30 μm is rigidly mounted, forming a cavity for collecting sludge and a cavity of partially purified water drained through the outlet pipe, the discharge pipe of the pump is connected to the ejector by a pipeline with a tap, the mixing chamber of which is connected to the air supply source and to the pipe for suction of the reagent from the tank, the outlet of the ejector is connected by a pipe to the pipe for supplying the mixture to the shell above a horizontal partition inside it made of highly porous cellular metal with a lyophobic coating and a pore size of 30 μm, over which a float of ferromagnetic highly porous metal is placed, ring magnets are installed on the outer side of the shell above the feed pipe, covered by a magnetic field concentrator to a height not less than the shell diameter , an additional centrifugal pump is connected to the outlet pipe through a non-return valve and a tap, the pressure line of which is connected to the pipeline of the filtration system and consisting of a filter with coalescing properties, one outlet of which is connected to the sorption filter, and the other outlet through a stopcock and check valve is connected to the inlet of an additional ejector, from the outlet of which the liquid enters the flotation chamber - into the sedimentation collection chamber above the inclined partition, ring magnets are mounted on the filter housing with coalescing properties.

Images