RU2253500C1 - Installation for separation of immiscible liquids - Google Patents

Abstract

FIELD: petroleum industry; equipment for separation of immiscible liquids.

SUBSTANCE: the invention is pertaining to the field of petroleum industry, in particular, to the installation of gravitational action used for separation of the immiscible liquids and may be used for purification of water from petroleum or oil products and mechanical impurities at stripping tanks and at liquidation of emergency oil spillages. The installation consist of an intermediate tank and a tank supplied with a neck, a connecting pipes for water unloading and petroleum discharge. Inside the tank there is a vertical partition for accumulation of the separated water, and vertical partitions for separation of a mixture for the water and the oil product. In the neck there is an installed vertical pipe, on the lower end of which there is a fixed expander made in the form of a cylinder with apertures along its perimeter hard-mounted is hermetically established. The vertical partition is mounted with a clearance to the horizontal part of the bottom and hermetically fixed on the lateral walls of the tank. The vertical partitions are placed by groups on both sides of the expander and are fixed on the lateral walls of the tank in a staggered row. The installation ensures an increased efficiency of separation of the immiscible liquids.

EFFECT: the invention ensures an increased efficiency of separation of the immiscible liquids.

2 cl, 2 tbl 3 dwg

Description

The invention relates to installations of the gravitational principle of action for the separation of immiscible liquids and can be used to purify water from oil or oil products and solids during tank cleaning and in the elimination of emergency spills.

A device for separating two immiscible liquids is known, comprising a reservoir with nozzles for supplying the initial mixture and withdrawing water and oil, inside of which there is a cup and a closed partition located in the cup under the nozzle for supplying the initial mixture, while the nozzle for draining the water is in the lower part reservoir (RU Patent No. 2066226 C1, CL B 01 D 17/028, 1996).

The disadvantage of this device is that the nozzle for removing water is located in the lower part of the tank, which requires constant monitoring of the operation of the device and strict adherence to the ratio of the amount of the supplied mixture and the amount of drained water. With an excess of the amount of the mixture entering the tank, the water level in the tank will increase, and the oil layer will decrease and part of the water will flow out with the oil. If there is not enough mixture entering the tank, the water level in the tank will decrease, which does not exclude a partial discharge of oil through the pipe to drain the water.

Closest to the claimed invention in technical essence is a device for separating two immiscible liquids, mainly water and oil, made in the form of a tank with internal vertical partitions and nozzles for supplying the initial mixture and draining the separated liquids located in the upper part of the tank, while the distance from the bottom of the tank to the lower edges of the nozzles for draining water H ₁ , oil H ₂ and the lower edge of the septum H ₃ installed in front of the nozzle for draining water, are connected by the ratio ia H ₁ : H ₂ = 1: (1.005-1.250); H ₁ : H ₃ = 1: (0.05-0.20), (SU Patent No. 1805991 A3, class B 01 D 17/02, 1993 - prototype).

The disadvantage of this device is the low separation efficiency of two immiscible liquids, due to the supply of the initial mixture into the tank with an open incident jet. Indeed, the falling stream of the mixture forms a vertical plume, which deepens into a layer of water already separated from the oil and mixes with the settled water.

In addition, during the separation process, the incoming mixture passes a straight path to the oil drain pipe, taking suspended water particles with it, and also due to the fact that a stagnant oil zone is formed in the tank in front of the vertical partition for water drainage, which practically does not participate in the mixture separation process .

The technical result of the invention is to increase the separation efficiency of immiscible liquids by eliminating the possibility of contact of the feed mixture with separated water under a layer of oil product and increasing the residence time of the mixture in the oil product.

This result is achieved in that the installation for the separation of immiscible liquids, including a tank with a neck and nozzles for draining water and oil products, the lower edges of which are located respectively at a distance of H ₁ and H ₂ from the bottom of the tank and are connected by the ratio H ₁ : H ₂ = 1: (1,005-1,250), vertical internal partitions, one of which is installed with the possibility of creating a cavity for the accumulation of separated water in front of the pipe for draining water with a gap of H ₃ relative to the bottom of the tank, associated with the distance H _{1 by the} ratio of H ₁ : H ₃ = 1 :( 0.05-0.20), prom a daily container for collecting mechanical impurities and a collector of deposited solid particles located in the lower part of the tank, according to the proposed invention, an intermediate container for collecting mechanical impurities is placed on the tank, and the installation further comprises a vertical pipe hermetically fixed in the neck of the tank, the lower end of which is removed from the bottom of the tank a distance H ₄ associated with H ₂ ratio of H _2: H ₄ = 1: (0,96-0,98), the upper end connected to the outlet pipe of the intermediate container spreader configured in the form of a glass with holes around the perimeter, rigidly fixed to the lower end of the vertical pipe, and the vertical partitions are divided into two groups symmetrically located from the expander, in each of which they are staggered to the side walls of the tank with a gap relative to the opposite side wall, the area of which is not less than the cross-sectional area of the vertical pipe, while the overall dimensions and the total area of the holes of the expander is selected from the following ratios:

d _ext. ≥ 1.5 D _tr. ;

h _ext. ≤ D _tr ;

S _holes ≥ S _tr ,

where D _tr. - diameter of the vertical pipe, mm;

d _exp is the diameter of the expander, mm;

h _ext. - height of the expander, mm;

s _resp. - the total area of the holes of the expander, mm ² ;

s _tr - cross-sectional area of a vertical pipe, mm ² ,

and also the fact that the installation is equipped with a second pipe for draining the oil, located at an equal height with the first pipe for draining the oil and mounted on the side wall in front of the cavity for the accumulation of separated water.

Figure 1 shows the installation for the separation of immiscible liquids (general view);

figure 2 is the same (view aa in figure 1);

figure 3 is the same (view according to B in figure 1).

Installation for the separation of immiscible liquids consists of an intermediate tank 1 and a tank 2, equipped with a neck 3, a pipe 4 for draining water and pipes 5 and 6 for draining the oil product. Inside the tank 2 there is a vertical partition 7, installed in front of the pipe 4 and designed to accumulate separated water, and vertical partitions 8, providing separation of the mixture into water and oil. A vertical pipe 9 is tightly installed in the neck 3, on the lower end of which an expander 10 is rigidly fixed. The bottom of the tank 2 consists of an inclined part 11 and a horizontal part 12 made in the shape of an ellipse. At the bottom of the tank 2 there are nozzles 13 and 14 with locking devices (not shown) for removing deposited solid particles. The intermediate tank 1 has a cover 15, an inlet pipe 16 for supplying the initial mixture and an outlet pipe 17, which is connected through a bend 18 to a vertical pipe 9. Inside the intermediate tank 1 there are metal mesh 19. The tank 2 has supports 20 in the lower part, and the intermediate tank 1 - supports 21, which are mounted on the tank 2. The intermediate tank 1 and the tank 2 are equipped with nozzles 22 and 23 for the release of gas.

The vertical partition 7 is installed with a gap of H ₃ in relation to the horizontal part 12 of the bottom, hermetically attached to the side walls of the tank 2 and provides a cavity for the accumulation of separated water. The vertical partitions 8 are placed in groups on both sides of the expander 10 and are staggered to the side walls of the tank 2, while to ensure a smooth movement of the mixture, each partition is set with a gap with respect to the opposite side wall, the area of which is not less than the cross-sectional area of the vertical pipe . Each group must have at least two vertical partitions.

The lower edges of the pipe 4 for draining water and pipes 5 and 6 for draining the oil are located respectively at distances H ₁ and H ₂ from the lower generatrix of the horizontal part 12 of the tank bottom.

The metal mesh 19 in the intermediate tank 1 has a different cell size, the size of which decreases along the flow, is mounted on a single supporting frame and can be removed in the intervals between the process of separation of the mixture for cleaning them from mechanical impurities or for replacement.

The inclined part 11 of the bottom, installed with a slope of at least 40 °, eliminates the formation of a stagnant zone of water and ensures the sliding of the deposited solid particles towards the pipe 14.

Pipes 5 and 6 for draining the oil product, if necessary, can be connected to each other by a pipe segment (not shown) and, thus, the installation will have a larger pipe at the outlet for draining the oil product.

The volume of the tank 2 and the diameter of the vertical pipe are selected depending on the hourly supply of the initial mixture.

To ensure effective separation of water from the oil product, a known method is used, which includes pre-filling the installation with water and oil product and feeding the mixture to be cleaned into the oil product layer, while the brand of oil product that is contained in the mixture to be purified is poured into the installation.

Were made breadboard samples of the inventive installation with the following ratio of distances H ₁ and H ₂ : H ₁ : H ₂ = 1: 1,03, which is in the range of the optimal ratios indicated in the known device.

The gap H ₃ between the vertical partition 7 and the bottom of the tank in the model samples is taken equal to 0.17 H ₁ , which is also within the optimal ratios indicated in the known device.

The characteristics of the prototypes of the inventive installation with a capacity of 15 l, made with transparent walls, are presented in table 1, and the results of their testing are shown in table. 2.

The installation is filled with water before it starts flowing out of pipe 4 and oil (non-depleted used M-6 ₃ / 10B engine oil) before it flows out of pipes 5 and 6. The thickness of the oil product is 50 mm.

The initial purified mixture was prepared by mixing the used M-6 ₃ / 10B engine oil with water in the proportions of 45 g of oil per 1 liter of water and 90 g of oil per 1 liter of water. In the process of supplying the initial mixture to the prototype of the installation, the initial mixture was constantly mixed. The feed was carried out at a speed of 1 l / min and 2 l / min. The oil concentration in the drained water in mg / l and the water content in the drained oil in% were determined by known methods (the water content in the oil product is in accordance with GOST 2477-65 (ST. SEF 2382-80), the concentration of the oil product in water is determined by column chromatography with gravimetric the end, PND F 14.1: 2, 116-97).

As tests have shown (Table 2), the best results for the separation of two immiscible liquids (water + oil) have samples of prototype plants No. 3, 4, 7, 8, 9, 10, 13, 14.

Reducing the gap between each vertical partition 8 and the tank wall (sample No. 1) impedes the flow of oil to the nozzles 5 and 6. As a result, the thickness of the oil layer in front of the nozzles 5 and 6 decreases, which leads to an increase in the water content in the oil being drained. At the same time, the thickness of the oil layer in the cavity of the extender 10 increases, which leads to an increase in the oil concentration in the drained water.

When the values of H ₄ less than 0.96 and more than 0.98 H ₂ (samples No. 2 and 5), the quality of the separated products is deteriorated due to the fact that in sample No. 2, where H _{4 is} less than 0.96 H ₂ , part of the original the mixture from the bottom openings of the expander enters under a layer of oil, which does not provide coarsening and rapid ascent of oil droplets, and the process of water deposition is slowed down. When the value of H ₄ more than 0.98 H ₂ (sample No. 5), part of the initial mixture spreads over the surface of the oil and particles of water, not having time to separate from the oil, merge with the oil.

The same results and similar processes are observed if the height h _ext. more D _tr (sample No. 11).

If d _exp. less than 1.5 D _tr (sample No. 6) and at S _holes less than S _tr. (sample No. 12), a more intensive outflow of the initial mixture from the expander is observed, which worsens the process of separation of the mixture into water and oil.

Thus, the optimal separation efficiency of two immiscible liquids in the inventive installation is achieved with the following ratios of structural elements:

H ₂ : H ₄ = 1: (0.96-0.98);

d _ext. ≥ 1.5 D _tr ;

h _ext. ≤ D _tr ;

S _holes ≥ S _tr .

and also when the gap between each partition 8 and the tank wall is not less than the cross-sectional area of the vertical pipe 9.

The fastening of the vertical partitions 8 on the side walls of the tank in a checkerboard pattern lengthens the path of movement of the mixture (i.e., the time spent by the mixture in contact with the oil increases).

The presence of the second pipe 5 for draining the oil ensures the creation of two flows of the mixture, reduces the speed of movement of the mixture in the horizontal plane, eliminates the formation of a stagnant zone of the oil in front of the vertical partition 7 and, therefore, increases the efficiency of separation of the mixture.

Installation works as follows.

Through the pipe 16 on the intermediate tank 1, water is first poured into the tank 2 before it starts to flow out of the pipe 4, then the oil product is poured before it flows out of the pipes 5 and 6, while a layer of oil is formed in the tank, and excess water flows through the pipe 4. Gases from the intermediate tank 1 and tank 2 are discharged through pipes 22 and 23. In this state, the installation is ready for operation.

The mixture to be cleaned is fed through a pipe 16 to an intermediate container 1, in which the mixture, passing through a metal mesh 19, is cleaned of large mechanical impurities. Next, the mixture consisting of water, oil and small mechanical impurities, through a vertical pipe 9 enters the expander 10, from which it enters the layer of oil through openings.

The mixture entering the tank 2, enveloping the vertical partitions 8, moves towards the nozzles 5 and 6.

In the process of moving to the nozzles 5 and 6, it is divided into water and oil. Water under the influence of gravitational forces sinks down, increasing the volume of flooded water, bends around the vertical partition 7 and merges through the nozzle 4. The oil product, separated from the water, is poured through the nozzles 5 and 6.

Solid particles accumulating on the bottom of the tank 2 are periodically removed through the nozzles 13 and 14. Large mechanical impurities remaining in the intermediate tank 1 are also periodically removed with the cover 15 removed.

The use of the invention will improve the separation efficiency of immiscible liquids.

Sources of information

1. RU. Patent No. 2066226 C1, cl. B 01 D 17/028, 1996.

2. SU. Patent No. 1805991 A3, cl. In 01 D 17/02, 1993 - a prototype.

Claims (2)

1. Installation for the separation of immiscible liquids, including a tank with a neck and nozzles for draining water and oil products, the lower edges of which are located respectively at a distance of H ₁ and H ₂ from the bottom of the tank and are connected by the ratio H ₁ : H ₂ = 1: (1,005-1,250 ), vertical internal partitions, one of which is installed with the possibility of creating a cavity for the accumulation of separated water in front of the pipe for draining the water with a gap of H ₃ relative to the bottom of the tank, associated with the distance H _{1 by the} ratio H ₁ : H ₃ = 1: (0.05- 0.20), an intermediate container for trapping mechanical impurities and collection of settled solids at the bottom of the tank, characterized in that the intermediate container for trapping solids placed on the tank, and the apparatus further comprises a hermetically attached to the neck of the tank a riser pipe, the lower end of which is removed from the bottom of the tank to a distance H ₄ , associated with H _{2 by the} ratio of H ₂ : H ₄ = 1: (0.96-0.98), the upper end is connected to the output pipe of the intermediate tank, the expander, made in the form of a glass with holes around the perimeter, is rigidly mounted on the bottom of the vertical pipe, and the vertical partitions are divided into two groups symmetrically located from the expander, in each of which they are mounted on the side walls of the tank in a checkerboard pattern with a gap relative to the opposite side wall, the area of which is not less than the cross-sectional area of the vertical pipe, this overall dimensions and the total area of the holes of the expander is selected from the following ratios: d _dil ≥ 1.5 D _tr ; h _exp ≤ D _tr ; S _holes ≥ S _mp where D _tr - the diameter of the vertical pipe, mm; d _exp is the diameter of the expander, mm; h _exp - the height of the expander, mm; _Holes S - total area of the holes expander mm ^2; S _Tr - the cross-sectional area of a vertical pipe, mm ² . 2. Installation according to claim 1, characterized in that it is equipped with a second pipe for draining the oil, located at equal height with the first pipe for draining the oil and mounted on the side wall in front of the cavity for the accumulation of separated water.

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