RU2772482C1 - Device for trapping oil, oil products and suspended solids in industrial and storm wastewater - Google Patents

Abstract

FIELD: industrial wastewater from oil cleaning.

SUBSTANCE: invention relates to devices for treating surface and industrial wastewater from oil (petroleum products) and suspended solids coming from storage tanks before they are supplied to treatment facilities or surface rainwater from the territories of objects of main oil pipelines and oil product pipelines. The device comprises pumps for supplying water to bottom sediment erosion systems, two parallel sections of tanks separated by a partition and placed on a support frame. The support frame contains a unit common for two sections for placing pumps for supplying water to the bottom sediment erosion systems. Each section contains accumulator-decanter, coalescence unit, purified water tanks with filter material, skimmers. The skimmers are located at the outlet of the accumulator-decanter and the coalescence unit. The accumulator-decanter consists of a fine separation unit, a system for washing out bottom sediments and a submersible pump. The coalescence unit consists of a module of coalescing thin-layer elements, a multi-sectional filter with a floating load, a submersible pump and a system for washing out bottom sediments. The tank of purified water with filter material contains a cassette filter with a filter load.

EFFECT: improving the quality of industrial and storm wastewater treatment based on reagentless technology, ensuring maintenance and repair of individual elements of the device without stopping with switching to the operation of only one section.

9 cl, 3 dwg

Description

The invention relates to devices for treating surface and industrial wastewater from oil (petroleum products) and suspended solids or surface rainwater from the territories of objects of main oil and oil product pipelines coming from storage tanks before they are supplied to treatment facilities.

From the prior art, a device for local treatment of storm water from impurities of oil products and suspended particles is known, disclosed in the utility model patent RU 170 603 U1 (IPC: G02F 1/40; published: 05/02/2017) and related to treatment facilities for the treatment of storm water from impurities of oil products and suspended particles and can be used in the treatment of rainwater from the territories of parking lots and gas stations.

The device for local purification of storm drains from impurities of oil products and suspended particles contains a receiving chamber with a cylindrical hatch and an inlet manifold having nozzles at the end, a settling chamber with a cylindrical hatch and a filtration chamber with an adsorption filler and a rectangular hatch, an outlet fitting. In this case, the inlet manifold nozzle has a conoidal shape. In the receiving chamber there are two mesh segments made of stainless wire. The settling chamber has two gratings with inclined shutters at the inlet, two gratings with inclined shutters are installed at the inlet to the filtration chamber. Block-modular segments with an adsorbent are placed in the filtration chamber, while the rims of the block-modular segments have rubber gaskets.

The disadvantage of this device is the inability to collect impurities of oil and oil products in a separate container. In addition, the device does not provide for the possibility of non-stop operation and in order to clean the filtration elements or replace them, the device must be disconnected from the inlet manifold and completely emptied. The device does not provide for wastewater treatment from mechanical impurities.

From the prior art, a device for treating surface wastewater from suspended solids and oil products is described in the patent for the invention RU 2 610 507 C2 (IPC: C02F 9/08, C02F 1/52, C02F 1/28, B01D 21/01, B01D 29 /11, C02F 103/44; published: 02/03/2017).

Initially, the initial wastewater enters the distribution chamber, equipped with a basket for cleaning the incoming wastewater from sand and large debris and a flocculant dosing device that allows proportional dosing of the reagent without using a dosing pump and electricity. Then the wastewater goes through the stage of additional mechanical treatment using an easily regenerated bag filter.

The bag filter is attached to the sand and coarse debris basket and is easily removed from the distribution chamber for regeneration (washing) after each rain or as needed. The stage of additional mechanical cleaning ensures the efficiency of cleaning from suspended solids of 50-75%, which makes it possible to reduce the load at the stage of the main cleaning, replace loads and unload the sludge from the cleaning unit no more than once a year. Carrying out additional mechanical treatment using an easily regenerated bag filter allows you to send heavily polluted surface runoff from the territories of industrial enterprises, solid waste landfills, oil refineries and oil depots, gas stations, parking lots for treatment.

In the purification unit, water passes sequentially from bottom to top through layers of filtering and sorbing media. The lower filter layer of cylindrical rings, filled in bulk, serves for uniform distribution of the flow and fine mechanical cleaning from suspended solids, as well as for the accumulation and compaction of the accumulated sediment, in the second layer of a highly efficient oil-absorbing polymer sorbent of the Uremix-913 brand, sorption of free and emulsified oil products, in the third layer of loading from a sorbent with attached microflora based on natural aluminosilicate brand S-Verad ® - additional sorption of dissolved oil products and fine suspended solids up to discharge standards into a fishery reservoir.

The disadvantage of the known solution is the impossibility of replacing the filter layers in connection with the use of the method of forming filtration layers in bulk. The invention has not worked out the issue of periodic cleaning from bottom sediments and mechanical impurities both at the sewage pumping station and at the cleaning device.

The prior art installation for the treatment of storm water, protected by a patent for the invention RU 2 289 548 C1 (IPC: C02F 1/40; published: 20.12.2006). The installation contains a receiving storage tank made in the form of a horizontally placed cylinder, in which treatment facilities are installed, including sand-collecting bins, the first stage of a block for separating suspended particles and oil products, made in the form of a thin-layer module from a bundle of pipes made of a material with a high coalescence coefficient, and the second stage of the block for separating suspended particles and oil products, made in the form of a container filled with free-floating granules of a material with a high coalescence coefficient. In a storm water treatment plant, the receiving storage tank is the primary settling tank, oil trap and sludge storage tank.

The placement of treatment facilities inside the receiving storage tank does not provide the possibility of non-stop operation of the installation and requires it to be stopped for periodic cleaning and washing.

The analyzed technical devices are analogues of the claimed invention, the prototype has not been identified. The proposed device for capturing oil and oil products from the surface of wastewater provides for a reagentless technology for mechanical purification of wastewater from oil products and suspended solids by settling and filtering with preliminary coalescing.

Settling of wastewater ensures the retention of coarse pollutants and oil products. Sedimentation of wastewater is provided by a higher rate of settling of suspended particles and a higher rate of emersion of oil products relative to the upward velocity of wastewater through the cross section of thin-layer modules in the tank. At the same time, thin-layer modules provide a large surface, in which the near-wall wastewater flow rate is equal to zero, to increase the efficiency of settling coarsely dispersed suspended solids and oil products.

Coalescing of oil products is based on the retention and accumulation of finely dispersed oil products on the surface of a hydrophobic material, followed by coarsening and detachment of coarse particles of oil products and ascent due to the difference in density of wastewater and oil products. The efficiency of coalescing depends on the surface area of the hydrophobic material, the width of the channels, and the rate of passage of wastewater through the hydrophobic material. The larger the particles of oil products formed as a result of coalescence, the more efficiently they are separated from wastewater by floating to the surface. The device provides two stages of coalescing: through thin-layer elements and through a layer of floating load. Filtration of oily wastewater is carried out with a hydrophobic material that ensures the retention of oil products in the volume of the load due to the capillary tension of oil products, as well as the mechanical retention of suspended solids in the fibrous structure of the load.

The technical objective of the invention is to improve the device for trapping oil, oil products and suspended solids in industrial and rainwater coming from storage tanks before they are supplied to treatment facilities or surface rainwater from the territories of objects of main oil and oil products pipelines.

The technical result achieved by the implementation of the invention is to improve the quality of industrial and storm wastewater treatment based on a reagentless technology for mechanical wastewater treatment from oil, oil products and suspended solids by settling and filtering with preliminary coalescing, to ensure maintenance and repair of individual elements of the device without stops with switching to work of only one section.

The technical problem is solved, and the technical result is achieved due to the fact that the device for trapping oil, oil products and suspended solids in industrial and rainwater, contains pumps for supplying water to the bottom sediment erosion systems, two parallel sections of tanks, separated by a partition and placed on a support frame with a block common to two sections for placing pumps for supplying water to bottom sediment erosion systems, each section contains a decanter accumulator, a coalescence unit, purified water tanks with filter material, skimmers located at the outlet of the decanter accumulator and coalescence unit, at the same time, the accumulator-decanter consists of a fine separation unit, a system for washing out bottom sediments and a submersible pump, a coalescence unit consists of a module of coalescing thin-layer elements, a multi-section filter with a floating load, a submersible pump and a system for washing out bottom sediments, a tank of purified water with a filter mat The serial contains a cassette filter with a filter load.

In addition, the specified technical result is achieved in particular cases of the implementation of the invention due to the fact that:

- fine separation unit is made in the form of thin-layer hydrophobic plates;

- the module of coalescing thin-layer elements contains profiled hydrophobic layers;

- multi-section filter with a floating load is made of expanded polystyrene granules with a particle size of 2-4 mm;

- multi-section filter with a floating load is made of cassette filters with a floating load, containing an over-filter zone for accumulating a volume of water for supplying to systems for washing out bottom sediments and separated by a partition;

- bottom sediment erosion systems of accumulators-decanters and coalescence units are made with the possibility of receiving water from tanks with purified water by means of pumps or water pipes;

- a cassette filter with a filter bed is made of a material with a microfiber-porous structure with inclusions of flakes and granules;

- the device for capturing oil, oil products and suspended solids is equipped with a heating system, an electrical heating system for pipelines, a power supply system, liquid level and temperature sensors;

- the device for capturing oil, oil products and suspended solids is equipped with a canopy.

The implementation of the invention is illustrated by drawings (figures 1-3), where:

fig. 1 - schematic layout of a device for capturing oil, oil products and suspended solids in industrial and rainwater wastewater;

fig. 2 - a variant of the existing standard scheme for cleaning from oil and oil products from the surface of wastewater;

fig. 3 - an example of the use of a device for trapping oil, oil products and suspended solids in industrial and rainwater wastewater in a typical scheme for cleaning oil and oil products from the surface of wastewater.

The figures indicate:

1 - tray for collecting oil and oil products of the skimmer;

2 - skimmer;

3 - flexible floating element of the skimmer;

4 - fine separation unit;

5 - submersible pump;

6 - accumulator-decanter pit;

7 - system of erosion of bottom sediments of the accumulator-decanter;

8 - pit of the coalescence block;

9 - system of erosion of bottom sediments of the coalescence block;

10 - module coalescing thin-layer elements;

11 - multi-section filter with floating load;

12 - cassette filter with floating loading;

13 - purified water intake tank

14 - storage tanks;

15 - static settling tanks;

16 - sewer pumping station for industrial rain and waste water;

17 - collector for collecting oil;

18 - sewer pumping station for settled wastewater;

19 - industrial rain and waste water treatment plant;

20 - sewer pumping station for industrial rain and waste water;

21 - device for trapping oil, oil products and suspended solids in industrial and rainwater wastewater;

22 - well for collecting sediment;

23 - well with a water seal;

24 - distribution chamber;

25 - sewage inflow pipeline;

26 - pipeline for the supply of treated wastewater;

27 - pipeline for supplying sediment to the collection well;

28 - pipeline for supplying captured oil to the collection;

29 - accumulator-decanter;

30 - coalescence block;

31 - tank of purified water with filter material;

32 - coolant supply pipeline;

33 - pipeline for receiving cooled coolant;

34 - pipeline for supplying wastewater to a device for trapping oil, oil products and suspended solids in industrial and rainwater wastewater;

35 - skimmer;

36 - 5-stage filter.

A device for trapping oil, oil products and suspended solids in industrial and storm wastewater (hereinafter referred to as a device for catching oil) is used both as a separate structure and as part of a system for cleaning oil and oil products from the surface of wastewater.

The oil recovery device includes pumps for supplying water to bottom sediment erosion systems, two parallel sections of tanks separated by a partition and placed on a support frame with a unit common for two sections for placing pumps for water supply to bottom sediment erosion systems.

Each tank section of the device for capturing oil contains the following main technological equipment: accumulator-decanter 29, coalescence unit 30, purified water tank with filter material 31, skimmer 2 (Fig. 1).

Accumulator-decanter 29 operates as a sump in which gravitational settling of suspended solids and their conglomerates with petroleum products, as well as the emergence of drops of petroleum products to the surface.

Each accumulator-decanter 29 includes a fine separation unit 4, a submersible pump 5, a system for washing out bottom sediments 7. Thin-layer hydrophobic plates are installed in the fine separation unit 4, which increase the sedimentation area and space efficiency, thereby ensuring the separation of lighter suspended solids. substances with a density of less than 1500 kg / m ³ and particles with a hydraulic fineness of more than 0.7 mm.

Oil products from the surface of the water, which is in the blocks of thin-layer separation 4, are removed by skimmers 2, placed at the outlet of the accumulator of the decanter 29, from the trays for collecting oil and oil products 1 of the skimmer 2 into the flexible floating elements of the skimmer 3 and, further, into the accumulation well of oil products ( not shown in Fig. 1). The sediment accumulated at the bottom is discharged into the storage well of oil products (not shown in Fig. 1) by submersible pumps 5 located in the pits of accumulators-decanters 6. To wash out bottom sediments and wash the sediment from the bottom of accumulators-decanters 29, systems are provided in the pits of accumulators-decanters 6 erosion of bottom sediments 7, into which water is supplied from treated water tanks 31 by pumps or from a water supply system.

Each coalescence unit 30 contains a module of coalescing thin-layer elements 10, a multi-section floating-load filter 11, a submersible pump 5, and a system for washing out bottom sediments 9.

Oil products are removed from the water surface of the coalescence block 30 by a skimmer 2 placed at the outlet of the coalescence block 30.

Purified water tanks with filter material 31 contain cassette filters with floating loading 12, which has a complex fibrous-porous structure with inclusions of flakes and granules, which allows water to pass quickly.

To ensure the operation of the oil recovery device at low temperatures at which water can freeze, the technological equipment of the oil recovery device includes a heating system (heat tracer), an electrical heating system for pipelines, a power supply system, a set of sensors (level, temperature), a set for connecting to communications and devices when working as part of a system for cleaning oil and oil products from the surface of wastewater (not shown in Fig. 1 - 3).

The device works as follows.

Preliminarily cleaned from mechanical impurities, industrial and storm sewage from the surface zone of accumulators-decanters 29 enters the lower part of coalescence blocks 30, which are equipped with gravity multi-section floating-load filters 11.

In the coalescence blocks 30, industrial and storm sewage is cleaned with an upward movement of water through layers of coalescing thin-layer elements 10, which are alternately inclined (for example, at an angle of 60 °) to the horizontal, due to the contact of small drops of oil products with a profiled hydrophobic surface of the layers, coalescence of small drops of oil products on the surface of thin-layer elements and the ascent of enlarged drops of oil products to the surface. In this case, gravitational sedimentation of suspended solids occurs. The distance between thin-layer elements in coalescence blocks 30 is less than in decanter accumulators 29, while the specific surface area of coalescence per unit volume is much higher. The structure and high surface area of the deposition module contributes to the coalescence (coalescence) of small droplets of undissolved oil products into larger ones, which contributes to their separation and ascent to the surface. Modules coalescing thin-layer elements 10 provide separation of floating particles of oil products larger than 0.2 mm.

The sediment accumulated at the bottom of accumulators-decanters 29 and coalescence units 30 is discharged by submersible pumps 5 into the sediment storage well 22 through a pressure pipeline 27 or into a tank truck (not shown in Fig. 1). Submersible pumps 5 are located in the pits of accumulators-decanters 6 and coalescence blocks 8. To wash out bottom sediments and wash away sediment from the bottom of accumulators-decanters 29 and coalescence blocks 30, bottom sediments erosion systems 7, 9 are provided in the pits, into which water is supplied from purified water tanks. water 31 pumps or from the water supply.

The water that has passed through the modules of coalescing thin-layer elements 10 is supplied for deeper purification to a multi-section filter with a floating load 11. Foamed polystyrene granules with a size of 2-4 mm are used as a load. Filtering is carried out from top to bottom. When filtering from top to bottom, water moves to a decreasing particle size of the load, which makes it possible to effectively purify industrial and rainwater wastewater with an increase in the dirt capacity of the filter layer. The small width of the water channels in the layer of the floating load and the large surface area of the floating load of the module of coalescing thin-layer elements 10 contributes to the merging (coalescence) of small drops of undissolved oil products into larger ones, which significantly contributes to their separation from the water to be purified and ascent to the surface.

Multi-section floating-bed filters 11 have several floating-bed cassette filters 12, each of which is separated by a solid partition, while each multi-section floating-bed filter 11 has a common above-filter zone for accumulating the volume of water for washing the filters. Filters are washed manually or automatically by pumps through electric gates (not shown in Fig. 1) in the direction coinciding with the direction of water flow during filtration. In the process of washing the floating coalescing bed, water from the above-filter zone rushes down and stretches the bed layer in height, as a result of which the granules are washed from impurities.

Wastewater pre-treated in the coalescence blocks 30 is directed through the overflow partition, which determines the water level in the trap device, to the lower part of the purified water tanks with filter material 31. Further, the wastewater generated by the pressure formed due to the difference in water level heights from the coalescence blocks 30 is directed in an upward flow into purified water tanks 31 for filtration through cassette filters with a floating load 12. The filter load consists of a material having a complex microfiber-porous structure with inclusions of flakes and granules, which allows you to quickly pass water.

Purified wastewater after floating-load cassette filters 12 is sent through overflow pipelines to the treated water intake tank 13. Regeneration of the filter material is not required, as the tank is depleted and clogging, the filter material must be replaced.

Purified water tanks 31 are equipped with suction nozzles for emptying or for supplying water to the bottom sediment erosion systems in decanter accumulators 7 and coalescence units 9 in manual mode by pumps through electric gates (not shown in Fig. 1).

The device for capturing oil can be used as an integral part of the system for cleaning industrial and waste water from oil and oil products at the site facilities of the fuel and energy complex. The existing typical scheme for cleaning oil and oil products from the surface of wastewater is shown in Fig. 2. An example of the use of a device for trapping oil, oil products and suspended solids in industrial and rainwater wastewater in a typical scheme for cleaning oil and oil products from the surface of wastewater is shown in Fig. 3. The composition and characteristics of equipment, as well as facilities that are part of the industrial and waste water treatment system from oil and oil products are given in the table.

The inventive device for trapping oil, oil products and suspended solids in industrial and rainwater wastewater (position 8 in the table) alone or as part of a system for treating industrial and wastewater from oil and oil products at the site facilities of the fuel and energy complex provides high-quality wastewater treatment from various types pollution, while the device has a design scheme that allows you to perform maintenance and repair of individual elements of the device with switching to the operation of only one section, additionally an element for capturing surface contaminants in the form of traces of oil and oil products - in case of failure, the skimmer 2 is promptly replaced without decommissioning of the entire device for repair work.

Due to an integrated approach to wastewater treatment (multi-stage and multi-stream), the proposed device provides a reduction in the load on the equipment of industrial rainwater and wastewater treatment plants, in particular on pressure flotation machines 6, providing a decrease in the concentration of oil content from 65 mg/dm ³ in accordance with typical technical solutions at the outlet of static sludge tanks 2 to 10 mg/dm ³ according to the proposed treatment scheme (Fig. 3), which will halve the amount of coagulant in the flotator and reduce its consumption by 50% (by 150 kg/year for a capacity of 5 m ³ / h, by 225 kg / year for a productivity of 10 m ³ / h and by 450 kg / year for a productivity of 20 m ³ / h). In addition, the device provides a reduction in the water cut of oil and oil products collected from the surface of wastewater from 50% to 5% due to the use of a skimmer.

Claims (9)

1. A device for trapping oil, oil products and suspended solids in industrial and storm sewage, characterized in that it contains pumps for supplying water to the bottom sediment erosion systems, two parallel sections of tanks separated by a partition and placed on a support frame with a common for two sections a unit for placing pumps for supplying water to bottom sediment erosion systems, each section contains a decanter accumulator, a coalescence unit, purified water tanks, at least two skimmers located at the outlet of the decanter accumulator and coalescence unit, while the decanter accumulator consists of from a fine separation unit, a bottom sediment erosion system and a submersible pump, a coalescence unit consists of a module of coalescing thin-layer elements, a multi-section filter with a floating load, a submersible pump and a bottom sediment erosion system, a treated water tank with filter material contains a cassette filter with a filter load. 2. The device according to claim 1, characterized in that the fine separation unit is made in the form of thin-layer hydrophobic plates. 3. The device according to claim 1, characterized in that the module of coalescing thin-layer elements contains shaped hydrophobic layers. 4. The device according to claim 1, characterized in that the multi-section floating-load filter is made of expanded polystyrene granules with a particle size of 2-4 mm. 5. The device according to claim. 1, characterized in that the multi-section filter with a floating load is made of cassette filters with a floating load, containing an over-filter zone for accumulating a volume of water for supplying to systems for washing out bottom sediments and separated by a partition. 6. The device according to claim. 1, characterized in that the bottom sediment erosion systems of accumulators-decanters and coalescence units are made with the possibility of receiving water from tanks with purified water by means of pumps or a water supply system. 7. The device according to claim. 1, characterized in that the cassette filter with a filter load is made of a material with a microfiber-porous structure with inclusions of flakes and granules. 8. The device according to claim 1, characterized in that it is equipped with a heating system, an electric heating system for pipelines, an electrical power supply system, and a set of liquid level and temperature sensors. 9. The device according to claim. 1, characterized in that it is equipped with a canopy.

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