RU2255903C1 - Device for purification of oily waste waters - Google Patents

Abstract

FIELD: oil-producing industry; agriculture and other industries; production of devices for purification of oily waste waters.

SUBSTANCE: the invention is pertaining to the field of oil-producing industry, in particular, to the devices for purification of oily waste waters of oil fields and may be used in other industries and agriculture, waste waters of which contain petroleum and oil products. The device contains the horizontal hydrocyclones hydraulically interconnected with oily waste waters settling tanks. The hydrocyclones on the outlet of the upper and lower drains have the cylindrical chambers, which are supplied with the water distributors made in the form of tubular perforated sewers. The sewers of the low discharge are placed in one settling tank, and the sewers of the upper discharge - in the other settling tank. In each settling tank a coalescing hydrophobic granular load is placed. The technical result consists in improved quality of purification of waste waters from petroleum and oil products.

EFFECT: the invention ensures improved quality of purification of waste waters from petroleum and oil products.

3 dwg

Description

The invention relates to techniques for cleaning oily wastewater from oil fields and can be used in other industries, agriculture, etc., the wastewater of which contains oil and oil products.

A device for purifying oily wastewater according to.with. USSR No. 1699935, C 02 F 1/00, B 01 D 17/038, publ. 12/23/91, Bull. No. 47, including a sedimentation tank with an oil collector, an emulsion inlet nozzle made with a diameter to length ratio of 1:10 - 1:50, a hydrocyclone chamber with a tangential inlet, which is equipped with a dispersant in the form of a nozzle, nozzles for the removal of purified water and trapped oil and sediment.

The disadvantages of this device is the low efficiency of treatment of oily wastewater due to the incomplete use of the energy of the swirling flow in the pipe connecting the sump and the pipe with a dispersant. This is due to the fact that almost all the energy of the swirling flow is spent on the separation of the emulsion into oil and water, and not on the coalescence of oil droplets when moving along the pipe.

A device for wastewater treatment according to.with. USSR No. 956438, C 02 F 9/00, publ. 09/07/82, Bull. No. 33, which is a combination of a hydrocyclone-sump and consisting of a source water supply pipe, a pressure hydrocyclone, a connecting pipe, distributors of the lower and upper discharge, respectively, a sump separated by a two-tier partition, pipes for draining purified water, oil and sludge.

This device is equipped with adjustable siphons, which are used to distribute and balance pressures in the system - a connecting pipe-sump, to stabilize the hydrodynamic regime of the cleaning process.

The disadvantage of this device is also the low efficiency of purification of oily wastewater due to the insufficient use of the energy of the swirling flow on the discharge of a hydrocyclone.

A device for wastewater treatment according to.with. USSR No. 1063784 A, IPC ⁶ C 02 F 1/70, publ. 12/30/83, Bull. No. 48, including a hydrocyclone with nozzles for supplying raw water, an outlet for the upper discharge of oil products and a lower drain of purified water, a device for distributing wastewater, a wastewater treatment chamber equipped with a vertical partition separating the chambers of the upper and lower drain of the hydrocyclone, inclined horizontally and in their upper parts are connected by a gap in the partition. This device is equipped with a metering pump, the suction pipe of which is in communication with the upper part of the sump, and the discharge pipe - with a pipe for supplying source water. The effectiveness of the developed device is achieved by artificially increasing the concentration of oil in the source wastewater.

The disadvantage of this device is its relative complexity and the inability to use the residual energy of the swirling flows on the discharge of a hydrocyclone.

The prototype of the invention is a device for the purification of oily wastewater according to the patent of the Russian Federation for invention No. 2189360, publ. 09/20/2002, bull. No. 26, including a pipeline for supplying source water, a pressure hydrocyclone, cylindrical chambers of an upper discharge and a lower discharge of a hydrocyclone. In the upper part of the working zone of the sump there are water distribution devices from the upper discharge and the lower discharge of the hydrocyclone, into which water flows from the corresponding cylindrical chambers. The sump has dividing walls dividing the sump into the working and buffer zones. In the upper part of the sump are oil collectors with pipes for oil drainage. A device for removing purified water with a chipper is located in the buffer zone of the sump. In the lower part of the sump there are pipes for sediment discharge. A layer of exfoliated oil forms in the upper part of the sump.

The disadvantage of this device is the low efficiency of purification of oil-containing wastewater (NSW) due to the mixing of the emulsion flows of the upper and lower discharge with each other and the emulsion contained in the upper part of the sump, which differ in phase-dispersion characteristics, and an emulsion with a high polydisperse internal oil phase, which reduces the effect of the coalescence process, and consequently, the treatment of oily wastewater (NSW).

The low cleaning effect of the LEL is also explained by the fact that the emulsion (LEL) from the cylindrical chambers of the upper and lower drains, entering the sump, passes through various numerous choking devices, local resistances (bends, tees, turns of the flow, sudden narrowing and expansion of the flow, etc.). e.), in which the velocity and turbulence of the flow increase by several orders of magnitude, which leads to a decrease in the redispersion of oil particles, which in turn leads to a decrease in the process of effective coalescence and, as a consequence, to the mind sheniyu cleaning effect.

In addition, the destruction of the armor shells of oil droplets and aggregate particles of mechanical impurities and the formation of finely dispersed particles accelerates the restoration and hardening of armor shells on finely dispersed particles of emulsion oil (NSW) when it moves along long pipelines leading this emulsion to the upper part of the sump. This fact also reduces the effect of purification of the NSW.

The invention is aimed at increasing the effect of purification of oily wastewater by improving the design of switchgears and placing switchgears in two separate sumps, as well as by placing coalescing hydrodynamic granular hydrophobic nozzles in the sumps.

The solution to the problem is achieved by the fact that a device comprising: horizontally positioned hydrocyclone with nozzles for supplying source water, drainage of the upper and lower drains, cylindrical chambers at the outlet of the upper and lower drains of the hydrocyclone; a sump equipped with partitions: not reaching the upper part and not reaching its lower part, dividing the sump into the working and buffer sections, in the upper part of the working section of the sump there are water distribution devices from the upper and lower drains of the hydrocyclone, pipes for oil drainage, purified water and sludge, according to the invention is equipped with an additional similar settling tanks and an additional similar hydrocyclone, while the settling tanks are hydraulically interconnected with hydrocyclones; the cylindrical chambers of hydrocyclones are equipped with water distributors, made in the form of pressure tubular hole collectors of the same diameter with cylindrical chambers, which are their continuation and located in the upper part of the settlers, while the upper part of the distribution manifold is located directly at the oil-water phase boundary; pressure tubular hole collectors of the lower discharge are located in one of the settlers, and the upper discharge in the other; settlers are located at a distance from each other of not less than 67 diameters of the cylindrical chamber of the hydrocyclone; each sump is equipped with a coalescing hydrodynamic hydrophobic coarse-grained granular load located between the partitions and 2/3 of the load height below the horizontal axis of the sump.

Figure 1 shows a schematic diagram of a device for cleaning oily wastewater (top view), figure 2 is a view according to I-I, figure 3 is a section along II-II.

The device consists of a pipeline 1 for supplying the initial oil-containing wastewater (NSW), a pressure tube 2 connected to pressure hydrocyclones 3, for example, six hydrocyclones or at least two hydrocyclones, and supply pipes 4 of the initial NSW. The pressure ring 2 serves to evenly distribute water among the hydrocyclones 3. The hydrocyclones 3 are connected by cylindrical chambers of the upper drain 7 and the lower drain 8 through the nozzles of the upper drain 5 and the lower drain 8. The upper drain chambers 7 are equipped with pressure tubular hole collectors 9. The lower discharge chambers 8 equipped with pressure tubular hole collectors 10. The tubular hole collectors 9 and 10 are a continuation of the cylindrical chambers 7 and 8, respectively, while the hole collectors 9 and 10 and cylindrical The cameras 7 and 8 have equal (identical) diameters and are interconnected by means of flanges. In the upper part of the collectors 9 and 10 there are holes 11 located in a checkerboard pattern at an angle of at least 45 ° to the vertical axis of the collector.

Hole collectors 9 and 10 are used to evenly distribute the initial NSW over the living cross section of the settling tanks 12 and 13. In this case, the hole collectors 9 are located in the upper part of the settling tank 12 and their upper plane at the level of the phase boundary 14 “oil (15) - water (16)” , and the hole collectors 10 are located in the upper part of the sump 13 and its upper plane at the level of the phase boundary 17 “oil (18) - water (19)”.

Sumps 12 and 13 (at least two sumps) are located at a distance of not less than 67d from each other (Fig. 3), where d is the diameter of the cylindrical chamber of the hydrocyclone, which allows optimal placement of cylindrical chambers of maximum length, hydrocyclones and equipment between the settlers, to reduce the piping length of the device strapping, simplify the strapping, reduce the number of different local resistances during strapping and layout of the device, reduce the occupied area of the device, and also contribute to the most economical layout and improving the working conditions of the device.

The lower part of the sump 12 is provided in the center with a tubular perforated collector 20 for collecting and removing sediment with holes located below, and above the collector 20, tube telescopic equal-arms collectors 21 are symmetrically located on both sides, equipped with nozzles 22 for flushing accumulated sediment from the bottom of the sump 12. Nozzles 22 are mounted perpendicular to the telescopic collector and are directed towards the hole collector 20.

The lower part of the sump 13 is also provided in the center with a tubular hole collector 23, tubular telescopic collectors 24, equipped with nozzles 25 of the same construction as described above, as for the sump 12.

Sumps 12 and 13 are equipped with coalescing hydrodynamic nozzles (filters) 26 and 27, respectively. The nozzles 26 and 27 are loaded with a granular coarse-grained hydrophobic material, for example polyethylene. Coalescing hydrodynamic nozzles 26 and 27 are located 2/3 of the loading height below the horizontal axis of the settlers and between partitions 28 and 29, not reaching the bottom of the settlers 12 and 13, respectively, and partitions 30 and 31, not reaching the top of the settlers 12 and 13 respectively. Partitions 28, 29, 30, 31 and coalescing hydrodynamic nozzles 26 and 27 of each settler 12 and 13 divide them into two sections: 32 and 33 - working sections and 34 and 35 - buffer sections. Hydrodynamic nozzles (filters) 26 and 27 serve to intensify the coalescence (enlargement) of oil droplets, which contributes to an increase in the effect of purification of the NSW by subsequent sedimentation. At the same time, nozzles 26 and 27 also contribute to the quenching of bottom flows, the fixation of sedimentation volumes and sediment accumulation.

The buffer sections 34 and 35 serve for additional purification by sedimentation of the NSW, which have undergone preliminary hydrodynamic treatment in coalescing nozzles 26 and 27.

In the lower part of the buffer section 34 of the settler 12, a tubular collecting hole collector 36 for collecting and removing sediment is placed, and above the collector 36, tubular telescopic equal-arm collectors 37 with nozzles 38 of a similar construction as described above are symmetrically located.

In the buffer section 34 of the settler 12, an arc-shaped tubular collector 39 with a pipe 40 and an arc-shaped chipper 41 are placed, which ensure uniform collection and removal of purified water over the live section of section 34, while the chipper 41 also helps to quench bottom flows, fixing additional volumes in the buffer section 34 sedimentation and sedimentation.

The buffer section 35 of the sump 13 is also equipped with a tubular hole collector for collecting and removing sludge, collectors with nozzles for washing the sludge, an arc-shaped tubular collector and an arc-shaped chipper of the same design as in the sump 12 as described above.

In the upper part of the sumps 12 and 13 are oil collectors 42 with nozzles 42 'for the removal of trapped oil.

The device operates as follows. The initial LEL containing floating and emulsified oil and mechanical impurities through pipeline 1 is supplied under pressure through a pressure distribution tube 2 to hydrocyclones 3 (for example, six hydrocyclones, but at least two hydrocyclones). In hydrocyclones 3, the NSW is hydrodynamically processed in the field of centrifugal mass as well as surface forces, as a result of which the armor shells on the particles (drops, globules) of oil and aggregates from mechanical impurities are destroyed, oil droplets become larger, the monodispersity of the internal oil phase of the NSW increases, and NSW also separates into two emulsion streams that differ in phase dispersion characteristics. The flow from the upper drains 5 of the hydrocyclones 3 enters the cylindrical chambers 7, and the flow from the lower drains 6 into the cylindrical chambers 8. The emulsion flows into the cylindrical chambers 7 and 8 in the form of swirling jets, while the time of the hydrodynamic processing of the emulsion (NSW) increases in a swirling field of mass forces whose energy is used for the most complete realization of all stages of the mechanism of destruction of oil emulsions (deformation and destruction of armor shells on oil globules; rapprochement, collision of drops; merging and enlargement of (coalescing) droplets, concentration, precipitation droplets selection of the dispersed phase in the form of continuous phase - bundle emulsion separation into oil and water) and, consequently, increases the efficiency of cleaning the PDR. Further, from the cylindrical chambers of the upper discharges 5, the emulsion stream (NSW) enters the tubular hole collectors 9, from the openings of which, in the form of a uniformly distributed stream of emulsion jets, it flows into the oil layer 15 (layer of a highly concentrated oil emulsion) of the settler 12. Emulsion jets flowing from the openings 11 hole collectors 9 create in the region of the phase boundary 14 “oil (15) - water (16)” a turbulent mixing zone, where intensive mixing of the NSW stream with the contents of a highly concentrated oil layer of em lsii (oil) 18, an intense and efficient coalescence of oil drops, the transition aggregated oil drops in the oil layer was caught 18, effective cleaning of the contact NSV oil, starting bundle NSV oil and water.

The emulsion flow (NSW) from the cylindrical chambers 8 of the lower discharge 6 enters the tubular hole collectors 10, from the openings 11 of which, in the form of a uniformly distributed stream of emulsion jets, is fed into the oil layer 18 (emulsion layer highly concentrated in oil) of the settler 13, emulsion jets flowing from holes 11 of the hole collector 9, create in the region of the phase boundary 17 “oil (18) - water (19)” a turbulent mixing zone, where there is intensive mixing of the stream of NSW jets with the contents of the oil layer 18, intense and efficient coales entsiya oil droplets transition aggregated oil drops in the oil layer was caught 18, effective cleaning of the contact NSV oil, starting bundle NSV oil and water.

At the same time, a high effect of cleaning the NSW from oil is achieved by the fact that when the emulsion flows in the form of swirling jets into cylindrical chambers 7 and 8 equipped with perforated distribution manifolds 9 and 10, the time of hydrodynamic processing of the emulsion in the swirling field of mass and surface forces increases whose energy is used for the most complete implementation of all stages of the mechanism of destruction of oil emulsions. In addition, the supply of a pre-hydrodynamically treated NSW in hydrocyclones 3 and cylindrical chambers 7 and 8 directly to the distribution manifolds 9 and 10 makes it possible to maximally exclude the passage of emulsions through various fitting devices 7 and local resistances, in which, as you know, the flow velocity and turbulence increase by 1-2 orders of magnitude, which can lead to a decrease in the diameter of oil globules by tens and hundreds of times and an increase in the polydispersity of the emulsion, which in turn leads to a decrease in the effec tive coalescence therefore NSV effect purification.

In the cavity of hydrocyclones 3, cylindrical chambers 7 and 8 and on their discharge, polydisperse emulsion flows (NSW) are formed, which differ in their internal phase-dispersed characteristics, namely, the polydispersity of the emulsion of the upper discharge is always greater (2-3 times or more) than the polydispersity of the emulsion of the lower discharge. The mixing of such flows and their simultaneous joint introduction into the sump determine the existence in the total flow of a whole spectrum of different diameters of oil droplets, which worsens the coalescence conditions. This fact reduces the effectiveness of the purification of the NSW.

Therefore, the separate input of the emulsion of the upper and lower discharges into separate settling tanks contributes to an increase in the cleaning effect of the NSW.

In the formation of durable armor shells, finely dispersed and colloidal substances contained in the NSW play an important role. The destruction in the hydrocyclone of the armor shells of oil particles and aggregate particles of mechanical impurities, their redistribution in the flow of the apparatus in the existing scheme of the hydrocyclone-chamber-distributors of the settler somewhat accelerates the restoration and hardening of the armor shells on drops of oil, which reduces the efficiency of the coalescence process and, consequently, the purification of the NSW.

In the proposed device for cleaning the NSW, the time of existence of the NSW treated in hydrocyclones 3 and the swirling flow of cylindrical chambers 7 and 8 is practically zero, since the treated NSW is introduced into the treatment zone at the interface 14 and 17 of the settling tanks 12 and 13 instantly through distributors 9 and 10, which are a continuation of the cylindrical chambers 7 and 8, respectively.

At the same time, hardening and the manifestation of the elastic properties of the armor, their effect on the process of coalescence of oil droplets are practically absent, which contributes to an increase in the cleaning effect of the NSW.

In the proposed device, the captured oil as it is accumulated is discharged through the oil collectors 42 and nozzles 42 '.

To remove accumulated sludge from the bottom of the working sections 32 and 33 of the settling tanks 12 and 13, pressure is supplied to the pressure collectors 21 and 24 through pipelines 43, which, flowing out of the nozzles 22 and 25, flushes the sediment to the pre-formed hole collectors 20 and 23, then washed sediment through pipelines 45 is discharged into the sediment compactor.

To remove the accumulated sludge from the bottom of the buffer section 34 and 35 of the settlers 12 and 13, water is supplied to the pressure collectors 47 through pipelines 44, which, flowing out of the nozzles 38, flushes the sediment to the collection hole collectors 36, then the washed sediment is discharged through pipelines 46 to sediment compactor.

Fine particles of oil carried out by the water flow from the working sections 32 and 33 of the settling tanks 12 and 13 are enlarged in the loading layers of the hydrodynamic coalescing nozzles 26 and 27, respectively, and float in the buffer sections 34 and 35, accumulate in the upper parts of these sections, and then are removed through oil collectors 42 and pipe 42 '.

The purified water is removed from the buffer sections 34 and 35 through the collectors 39, chippers 41 and nozzles 40.

The advantages of the proposed device are its high cleaning effect, high specific productivity, relatively lower weight of the individual apparatuses that make up the device, high stability and completeness of the completion of the coalescence and purification processes of NSW with very unequal quantitative and qualitative parameters of the initial emulsion; compactness of the device and highly industrialized manufacturing and installation; the opportunity to create and implement an effective technology for purification of NSW at the lowest material, labor and energy costs.

Claims (1)

A device for cleaning oily wastewater, including a horizontally mounted hydrocyclone with nozzles for supplying raw water, drainage of the upper and lower drains, cylindrical chambers at the outlet of the upper and lower drains of the hydrocyclone; a sump equipped with partitions: not reaching the upper part and not reaching its lower part, dividing the sump into the working and buffer sections, in the upper part of the working section of the sump there are water distribution devices from the upper and lower drains of the hydrocyclone, pipes for oil drainage, purified water and sludge, characterized in that it is equipped with an additional similar sump and an additional similar hydrocyclone, while the sumps are hydraulically interconnected with hydrocyclones; the cylindrical chambers of hydrocyclones are equipped with water distributors, made in the form of pressure tubular hole collectors of the same diameter with cylindrical chambers, which are their continuation and located in the upper part of the settlers, while the upper part of the distribution manifold is located directly at the oil-water phase boundary; pressure tubular hole collectors of the lower discharge are located in one of the settlers, and the upper discharge in the other; settlers are located at a distance from each other of not less than 67 diameters of the cylindrical chamber of the hydrocyclone; each sump is equipped with a coalescing hydrodynamic hydrophobic coarse-grained granular load located between the partitions and 2/3 of the load height below the horizontal axis of the sump.

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