RU2160714C1 - Plant for cleaning water from petroleum products and mechanical admixtures - Google Patents

Abstract

FIELD: cleaning natural water and sewage from petroleum products, oil and mechanical impurities. SUBSTANCE: proposed plant includes vertical cylindrical housing with supply and discharge branch pipes, inner cylinder located along axis of housing around central delivery pipe and filled with filtering coalescent material; plant is additionally provided with coalescent chamber mounted under housing; lower part of central pipe is located coaxially in chamber equipped with cone-shaped cover where branch pipe for discharge of mechanical impurities is located. Cylindrical part of chamber is provided with branch pipe for tangential delivery of contaminated water. Coalescence chamber is filled with polypropylene granules possessing positive buoyancy; partition is mounted between inner cylinder and housing; inner cylinder is made in form of changeable cartridge fitted with pipe union for draining petroleum products; this pipe union has of filtering coalescent materials laid in definite succession. Cartridge is also provided with perforated baffles separating these layers. Besides that, inclined baffle made in form of truncated cone is secured to central pipe in upper portion of cartridge; level regulator for control of water level in cartridge is mounted above point of attachment of baffle. Proposed plant provides for high efficiency and productivity without impairment of quality of water in case of high concentration of petroleum products at inlet and rise of water pressure, as well as efficient removal of floating, emulsified, colloidal and dissolved oil petroleum products bringing their content in purified water to permissible concentration. EFFECT: high compactness; simplified construction; low cost of manufacture and servicing; low power requirements. 7 cl, 1 dwg

Description

 The invention relates to the field of water treatment, in particular to installations for the purification of natural and waste water from oil, oil products, mechanical impurities and can be used in many sectors of the national economy, for example, in the oil, oil refining and chemical industries, in sea and river transport for cleaning bilge-ballast ship water, in the municipal economy for the treatment of storm and rain water, production wastewater from gas stations and car washes.

 The content of petroleum products in the treated water can vary within a very wide range and despite the presence of a large number of technical means and materials for removing petroleum products from water, the requirement to create an effective, efficient, universal installation remains relevant. The most acute question is in cases of emergency oil product spills, when the treated water contains a large amount of oil products and it is necessary not only to quickly clean the water, but also to collect oil or oil products for further disposal.

 In many cases, it is necessary to purify water not only from oil products, but also from associated mechanical impurities, and oil products can be contained in water not only in a floating state, but also in colloidal, emulsified and dissolved form. Therefore, the most effective known treatment plants are, as a rule, separators containing filtering, coalescing and sorption materials that allow maximum purification of water to the maximum permissible concentration (MPC) of oil products.

 A known installation for treating wastewater from oil products and solid impurities, including a cylindrical body with a lid and with a pipe installed in its upper part for the removal of oil products, pipes for entering the wastewater into the body and removing purified water, as well as a coalescing chamber located inside the body, a sump and an additional purification chamber, and at the inlet of wastewater into the casing, it is additionally equipped with a magneto-hydrodynamic inductor to reduce the stability of the wastewater, the casing is equipped with n also the lower hydrophobic, middle hydrophilic and upper hydrophobic perforated partitions, as well as a central pipe with a glass mounted on it, made with a conical bottom and forming a gap with the upper partition, a coalescing chamber is enclosed between the lower and middle partitions, a sump and an additional cleaning chamber between the middle and the upper partitions, and the upper partition is installed below the pipe for the removal of petroleum products and is movably connected to the housing cover, the lower part of the housing is made in connection enii cylinder with smaller diameter to form a water distribution chamber (RF Patent 2114786, cl. C 02 F 1/40, 1998).

 The design of this installation provides a high degree of purification from solid impurities, an increased filter cycle and a sufficiently high depth of purification from oil products (up to 99.5%), however, it is not effective enough for purifying water with a high content of oil products at the inlet, especially finely emulsified ones, and also does not differ stable operation with a sharp drop in water pressure at the inlet.

 Closest to the proposed technical solution is the installation for the separation of water-oil dispersed mixtures, which is used to purify natural and waste water from dispersed oil products, followed by their disposal, described in RF patent 2129899, cl. B 01 D 17/022, 1999.

 The installation includes a closed vertical cylindrical body with a branch pipe for the removal of oil products installed in its upper part and located above the outlet of purified water by an amount X, a branch pipe for the input of contaminated water in the lower part of the body along the central pipe, a branch pipe for the outlet of purified water, and also located along the axis of the case around the central pipe, the filter element is an inner cylinder filled with two layers of filter-coalescing material, including oleophilic, fibrous, and having a bottom supporting th perforated baffle.

 This installation with a filter element in the form of two layers of material with oleophilic and hydrophilic properties provides high quality cleaning of dispersed mixtures containing petroleum products, practically does not require regeneration of the filter load, however, despite a number of advantages, this separator cannot provide stable, highly efficient operation and performance during water purification with the content of petroleum products in different physical conditions and sharp fluctuations in the water pressure at the inlet to the installation.

 The objective of the proposed technical solution is to eliminate the above disadvantages of the known installations, as well as the creation of an inexpensive, powerful, but compact installation that works almost independently without reducing the quality of water treatment with a sharp increase in pressure and concentration of oil products at the inlet of the installation and at the same time separating floating, emulsified , colloidal and dissolved oil and oil products, as well as mechanical impurities.

 The problem is solved in that the proposed installation for water purification from oil products and mechanical impurities, including a closed vertical cylindrical body with a pipe for the removal of oil products installed in its upper part and located above the purified water outlet, a pipe for the input of contaminated water in the lower part of the case along the central the pipe, the outlet pipe for purified water, as well as the inner cylinder located along the axis of the housing around the central pipe, filled with layers of a filter-coalescing material according to the invention, is additionally equipped with a coalescing chamber mounted under the housing in the form of a cylinder with a cone-shaped cover, while the lower part of the central pipe is placed coaxially in the upper, cylindrical part of the chamber, in which a nozzle for tangential input of contaminated water, and a nozzle for removing mechanical impurities is installed in the lid, the chamber being filled with polypropylene granules with a positive buoyancy, between the inner cylinder and the body there is a coaxial baffle that sets the water flow rate, the inner cylinder is made in the form of a replaceable cartridge equipped with a nozzle for draining oil products and containing layers of filter-coalescing material, located from top to bottom in the following sequence: polypropylene granules with positive buoyancy and coated with surface-active substances (surfactants), a fibrous sorbent, finely dispersed coalescing material and another layer of fibrous bent, in addition, in the cartridge there are two perforated partitions that limit the upper layer of polypropylene, and in addition in the upper part of the cartridge above the grill, an inclined partition is attached to the central tube in the form of a truncated cone, facing down with a smaller base, and in the upper part of the central pipe, above the mount inclined partitions mounted regulator to maintain a given water level in the cartridge.

 The problem is also solved by the fact that the coalescing chamber is 10-40% by volume filled with polypropylene granules with positive buoyancy, and also that the upper part of the cartridge is filled with polypropylene granules with positive buoyancy by 70-90% by volume.

 In addition, as a finely dispersed coalescing material located between two layers of fibrous sorbent, it is preferable to use the filter material "perlite-M".

 The proposed installation is also characterized by the fact that the upper perforated partition and the supporting perforated partition are removable, the inclined partition is installed with the possibility of changing the angle of inclination.

 To solve this problem as a surface-active substances use substances that are not washed off the surface of the polypropylene granules neither water nor petroleum products.

 The drawing shows a General view of the proposed installation in longitudinal section.

 The installation is a gravitational, coalescing separator and contains a closed vertical cylindrical housing 1 with a coalescing chamber 2. A partition 3 is installed inside the housing, providing a predetermined outlet water level. The casing is also equipped with a pipe for supplying contaminated water 4 with a tap 5, a pipe for discharging purified water 6 and oil 7 with corresponding valves 8, 9. The casing also includes an emergency overflow pipe 10, a complete drain of water 11 with a valve 12, a central water supply pipe 13 from the coalescing chamber to a replaceable filter cartridge 14. The lower part of the coalescing chamber is closed with a conical cover 15 with a pipe 16 and a valve 17 to remove solid solids.

 In the housing 1 along its axis around the central pipe 13, an inner cylinder is installed in the form of a replaceable cartridge 14, equipped with a fitting 18 for draining oil products. In the cartridge on the Central tube 13 in its upper part there is an inclined partition 19 in the form of a truncated cone, facing a smaller base downward and configured to change the angle of inclination. Perforated partitions 20, 21, 22 are also installed in the cartridge, the housing is divided into zones and a stream of purified water is organized.

 On the central supply pipe 13 in its upper part, above the fastening of the inclined partition, a regulator 23 is installed, the task of which is to maintain a given water level in the cartridge, which ensures a predetermined level difference Δh at the inlet and outlet of the cartridge and, accordingly, the productivity of the installation, independent of pressure fluctuations on entrance to the installation.

The drawing also indicates the working chambers of the installation:
I - coalescing chamber 2, 10-40% filled by volume with polypropylene granules with positive buoyancy, II - coalescing chamber 24, III - contact cleaning chamber for oil 25, IV - coalescing chamber 26, V - final cleaning chamber 27, II and IV - chambers are 70-90% filled by volume with polypropylene granules with positive buoyancy and specially coated with surface-active substances that are able to hold a thin film of oil products on the granule surface, which can dramatically increase the coalescing ability of grains zero polypropylene. The composition of the surfactant is selected so that they are not washed off with granules neither water nor oil products. For example, a mixture of 3 parts by weight can be used. glycerin and 2 parts by weight hydroxyoxyacetanilide. The coalesced oil product accumulates in the cells of the spatial lattice and then its excess is squeezed to the surface and removed from the volume without clogging the load. Chamber III is designed for free floating of coalesced drops of oil and oil products to the surface of the water, and chamber V is filled with fine-grained coalescing material “perlite-M” and the final cleaning of water from traces of oil products takes place in it.

 The inclined partition 19 allows you to organize the movement of water in chambers II and IV with a variable speed over the cross section of the chambers. The angle of inclination of the partition 19 can be selected in a wide range from 30 to 180 degrees. to ensure a given law of change in flow velocity over the cross section of the chambers.

 The concentration of petroleum products in water as it moves through chambers II-V decreases. Reducing the flow rate of the water stream allows you to clean it from smaller particles of oil products.

 To prevent contamination of polypropylene granules and leaching of fine fractions by the water flow during the operation of the unit, Perlite-M is placed between two layers of fibrous material 28, which also serves as a sorbent.

 Partitions 20 and 22 are made removable to provide loading and unloading of active materials after the development of their resource.

 Installation works as follows.

 Before the cleaning process, the installation is prepared for operation.

 Place a replaceable filter cartridge 14 in the installation, fix it and install the regulator 23. Close the taps 5, 12, 17, open the valve 8 and fill the installation with clean water to the level of the partition 20. Connect the installation to the network with purified water and open the valve 5. Regulator 23 set the water level in the filter cartridge slightly below the level of the pipe 18.

 The cleaning process is as follows.

 The purified water through the pipe 4 enters the coalescing chamber 1, tangentially providing a swirling flow. In this case, particles of solid impurities under the action of centrifugal forces are discarded to the outer wall and fall down. In the first chamber on the surface of the polypropylene granules in a swirling stream of water, the first phase of the enlargement of oil particles occurs.

 Then the water rises through the central pipe 13 and through the level regulator 23 the purified water enters the lower part of the coalescing chamber 11, the volume of which is limited by an inclined baffle 19, where coalescence of smaller droplets occurs on the surface of the polypropylene granules in a stream of water with a decreasing flow rate over the section of the chamber petroleum products. At the exit of the chamber 11, the direction of the water flow changes to the opposite.

 In the contact cleansing chamber of oil products III, coalesced drops of oil float, replenishing the layer of oil products on the surface of the water.

 In coalescing chamber IV, water with a decreasing cross section of the chamber passes through a layer of polypropylene granules, where coalescence of even smaller droplets of oil occurs, which accumulate in the inter-pore spaces of the granules and are squeezed out into the upper part of the chamber and then into chamber III and merge with the oil product layer.

 Next, the water flow passes through the first layer of fibrous sorbent 28 and then through the layer of hydrophilic finely dispersed coalescing material “perlite-M” 27 and the second layer of fibrous sorbent 28, on which the final purification of water from oil products occurs. As a fibrous sorbent, non-woven needle-punched structural materials or a synthetic winterizer type material can be used.

 The purified water rises in the gap between the partition 3 and the replaceable filter cartridge 14, overflows through the partition and through the pipe 6 and the valve 8 is removed from the installation.

 When the installation is in operation, a high degree of water purification from oil products (not more than 0.05 mg / l) and a long duration of continuous operation (about 6 months) are achieved, which is achieved by the duration of continuous operation (about 6 months), which is also achieved by self-cleaning of polypropylene granules in chambers II and IV from oil products. In chamber V, water is treated after traces of oil products and the adsorption capacity of this chamber is sufficient for this period.

 The plant capacity is about 1.5 cubic meters per hour with minimum overall dimensions and inlet pressure up to 3 atm. The movement of purified water in chambers II and III occurs in laminar mode at a speed of 10-12 m / h. The unit can operate in continuous flow mode.

 At the end of its service life, the filter cartridge is replaced by another. For this, without stopping the supply of purified water to the installation, the tap 8 is closed, which leads to an increase in the water level in the gap between the housing 1 and the partition 3 and, as a result, an increase in the level of water and floating oil products in chamber III. Oil products are drained through the valve 9. Next, the flow of purified water to the installation is stopped by closing the valve 5, and all water is drained from the installation by opening the taps 8 and 12. Remove the regulator 23 and replace the filter cartridge 14 with another. The installation is ready for further work.

 Filter elements can be replaced no more than twice a year.

 The proposed installation is compact, simple and inexpensive to manufacture and maintain, does not consume electricity, has high efficiency and productivity, does not allow for a decrease in water quality with a sharp increase in the concentration of oil products at the inlet of the installation and at an increase in water pressure, and also ensures efficient discharge from wastewater simultaneously floating, emulsified, colloidal and dissolved oil and oil products, bringing their content in purified water to the level of maximum permissible concentrations, which Allows you to drain purified water into reservoirs of fishery value. Such a plant, which is a powerful new-generation separator, can reduce the number of treatment facilities currently in use. If necessary, several separators can be used to increase efficiency and productivity.

Claims (7)

 1. Installation for water purification from oil products and mechanical impurities, including a closed vertical cylindrical body with a pipe for the removal of oil products installed in its upper part and located above the purified water outlet, a contaminated water inlet pipe in the lower part of the body through a central pipe, a purified discharge pipe water, as well as an inner cylinder located along the axis of the housing around the central pipe, filled with layers of filtering coalescing material, including fibrous, and having a bottom under holding a perforated partition, characterized in that it is provided, mounted under the housing, with a coalescing chamber in the form of a cylinder with a cone-shaped cover, while the lower part of the central pipe is placed coaxially in the upper, cylindrical part of the chamber, in which there is also a pipe for tangential entry of contaminated water, and in the lid there is a pipe for removing mechanical impurities, the chamber being filled with polypropylene granules with positive buoyancy, between the inner cylinder and the body axially a partition that sets the flow rate of water, the inner cylinder is made in the form of a replaceable cartridge equipped with a fitting for draining oil products and containing layers of filtering coalescing material, located from top to bottom in the following sequence: polypropylene granules with positive buoyancy and coated with surface-active substances, fibrous sorbent, fine coalescing material and another layer of fibrous sorbent, in addition, two perforated partitions are located in the cartridge, bordering the top layer of polypropylene, and additionally in the upper part of the cartridge, above the grill, an inclined partition is attached to the central pipe in the form of a truncated cone, facing down with a smaller base, and in the upper part of the central pipe, above the fastening of the inclined partition, a regulator for maintaining the given water level in the cartridge is installed .  2. Installation according to claim 1, characterized in that the coalescing chamber is 1 to 40% by volume filled with polypropylene granules with positive buoyancy.  3. Installation according to any one of paragraphs.1 and 2, characterized in that the upper part of the cartridge is filled to 70 - 90% by volume with polypropylene granules with positive buoyancy.  4. Installation according to any one of paragraphs.1 to 3, characterized in that as a finely dispersed coalescing material using "perlite-M".  5. Installation according to any one of claims 1 to 4, characterized in that the upper perforated partition and the supporting perforated partition are removable.  6. Installation according to any one of paragraphs.1 to 5, characterized in that the inclined partition is made with the possibility of changing the angle of inclination.  7. Installation according to any one of paragraphs.1 to 6, characterized in that as surface-active substances use substances that are not washed off from the surface of polypropylene granules with either water or petroleum products.