RU2022933C1 - Device for purification of oil-containing waste water - Google Patents

Abstract

FIELD: purification of oil-containing waste water. SUBSTANCE: device has initial water feeding pipe-line, hydrocyclone unit with upper and lower drainage collectors, settling chamber with units of withdrawal of separation products, and flotation chamber. Lower part of flotation chamber communicates with settling chamber, its upper part communicates with the chamber of incompletely purified water. Hydrocyclone unit is in the form of multicyclone. Lower drainage collector is in the form of chamber connected to settling tank by pipe-line. Lower drainage collector is positioned above chamber of incompletely purified water and communicates with it through branch pipes mounted coaxially under lower drainage units of hydrocyclones. Initial liquid feeding pipe-line has vertical section and is provided with gas collector. Upper drainage collector is in the form of pipe connected to flotation chamber and mounted coaxially with water feeding pipe-line. EFFECT: enhanced purification capability. 1 dwg

Description

 The invention relates to the purification of industrial formation, wastewater from oil and mechanical impurities and can be used in the oil, oil refining and chemical industries.

 The closest in technical essence and the achieved effect to the invention is a device for the separation and degassing of liquids, including a hydrocyclone with nozzles for the exit of light and heavy phases, a settling tank with nodes for the separation of separation products and a feed pipe for the source liquid.

 The disadvantages of the device are low productivity and cleaning efficiency, as well as insufficient reliability in operation when changing the supply pressure of the source water.

 The drawing shows a General view of a device for the treatment of oily wastewater.

 A device for the treatment of oily wastewater includes a settling chamber 1 with taps of separation products 2, 3, 4, on which a flotation chamber 5 with a gas distributor 6 in the lower part and a cylinder conical 7 forming a chamber 8 of incompletely purified water in the upper part, a hydrocyclone assembly are vertically mounted made in the form of a multicyclone 9 and equipped with nozzles for an upper drain 10, a lower discharge receiving chamber 11 mounted above the flotation chamber 5 and connected via a pipe 12 to a settling chamber 1 and with a flotation chamber 5 by means of nozzles 13 located coaxially under the lower drains of the multicyclone 9, a pipe coaxially mounted with a water supply pipe 15 and forming a receiver for the upper drain. The water supply pipe 15 is made with a vertical section and is equipped with a reflector 16 and a gas collector 17 connected to the gas distributor 6 by means of a pipe 18.

 A device for cleaning oily wastewater works as follows.

 In industrial wastewater, especially reservoir oil fields, there is a gas both associated and residual from the gas lift system. Gas is present in three states: free in the form of plugs, coarse bubble different distribution in water, in acclaimed and dissolved states. Moreover, as a rule, wastewater flows unevenly (due to the technological cycles of the water collection process) both in terms of flow and pressure in the pipelines, respectively. Fluctuations in pressure are 0.15 MPa, i.e. from 0.12 to 0.27 MPa.

 With a sufficient pressure of 0.2-0.25 MPa at the inlet of the multicyclone and an average degree of contamination of 300-1000 ml / l, the initial wastewater is supplied through line 15. Since the inlet section of the line 15 is vertical, the free state gas contained in the source slightly ahead of water, it rises and accumulates in the gas collector 17. From pipeline 15, water with gas residues and contaminants is evenly distributed over the hydrocyclones of multicyclone 9 and, under the action of centrifugal forces, is divided into two flows: the upper discharge is oil and gas water mixture, and the bottom discharge - water with mechanical impurities. The upper drain through the pipe 10 and the receiver 14 of the upper drain is directed vertically downward, and then after the reflector 16 is sent to the flotation chamber 5, where the bulk of the oil floats. Water with oil residues enters the upper part of the settling chamber 1. The lower discharge of hydrocyclones, containing mechanical impurities and oil residues, fan out under the action of centrifugal forces and enters the chamber 11, from where it flows through the pipe 12 to the lower part of the settling tank 1.

 With insufficient pressure at the entrance to the hydrocyclones (less than 0.15 MPa) and a high degree of contamination of the initial liquid (more than 1000 ml / l of oil) in the hydrocyclones of the multicyclone 9, a weak swirl of the flow occurs and centrifugal forces are insufficient to separate the waste fluid into two streams. Therefore, almost all water flows through the lower discharge of hydrocyclones in the form of a direct or slightly swirling jet. It enters the nozzles 13 and through them into the chamber 8 of incompletely purified water, and from it flows into the flotation chamber 5. The gas accumulated in the gas collector 17 through the pipe 16 enters the gas distributor 6.

 In the settling tank 1, under the influence of gravitational forces, the upper stream with oil and the lower stream with mechanical impurities are finally cleaned by settling. Caught oil is discharged through pipeline 2, purified water is discharged through pipeline 3, and sediment is discharged through pipeline 4 as it accumulates.

 The lengthening of the feed water pipe allows the formation of gas and light large contaminants. The use of the separated gas supplied to the gas distributor, which is equipped with the lower part of the flotation chamber, allows you to speed up the cleaning process, lower the concentration of oil in the purified water.

 Equipping the flotation chamber with a baffle with a hole and nozzles forming a receiver of incompletely purified water allows a decrease in the concentration of oil and solids in purified water.

 At low pressures at the inlet to the hydrocyclones, when the wastewater is supplied for cleaning at insufficient pressure and a high degree of contamination, there is a slight twist and centrifugal forces are insufficient to separate the wastewater into the upper and lower flows. Almost all of the water flows through the lower discharge of the hydrocyclone in the form of a direct or weakly swirling jet containing inseparable pollution. For its reception, the flotation chamber is equipped with a partition with holes and nozzles coaxially located under the hydrocyclones.

Claims (1)

 DEVICE FOR CLEANING OIL-CONTAINING WASTE WATER, including a source water supply pipe, a settling tank with separation units for separation products, a hydrocyclone unit with bottom and top discharge receivers, characterized in that it is equipped with a flotation chamber with a gas distributor in the lower part, a cylinder-conical chamber of incompletely purified water, the water supply pipeline is made with a vertical section and is equipped with a gas collector in communication with the gas distributor of the flotation chamber, the hydrocyclone unit is made in e of a multicyclone, the bottom discharge receiver of which is made in the form of a chamber connected by a pipeline with a settling tank and to the incompletely purified water chamber by means of nozzles located coaxially under the lower drains of the multicyclone, the upper drain receiver is made in the form of a pipe coaxially mounted with the pipeline water supply.

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