SU1416444A1 - Separator for purifying oil-containing ship-borne water from petroleum products - Google Patents

Abstract

This invention relates to the purification of oily water from petroleum products on ships and drilling platforms. The aim of the invention is to improve the quality of the cleaning of the oil containing water from petroleum products by preventing the loading of mechanical impurities. The separator consists of a housing 1, an immersion bottom 2 and a cover 3. The housing is made of a sump 11 and a filter formed by concentrically mounted cylindrical partitions 8 and 10. The filter is divided by a partition 9 into cavities 13 and 14, in which the coalescing load is placed. Between the sump 11 and the central cavity 15 a flow swirler 21 is placed with a collector (C) 22. mechanical impurities. The view of the purified water is carried out via nozzles 6. Water containing petroleum products and mechanical impurities, in the process of moving through the sump 11, is freed from the coarse-dispersed part of the petroleum product. The swirler 21 provides for the creation in the flow of a centrifugal force, under the action of which the mechanical impurities are separated from the flow and provides additional coalescence of the oil product. The isolated mechanical impurities are deposited in С 22. The coarsening of fine petroleum product is provided by coalescing nozzles in cavities 13 and 14. 2 3.p. f-ly, 2 ill. from ate od 4 4 4

Description

The invention relates to the purification of oily water from petroleum products on ships and drilling platforms and can be applied to the enterprises of the oil-bearing and oil-refining industries, auto enterprises and other industrial facilities where oil-bearing waters are formed.

The purpose of the invention is to improve the quality of purification of oily water from petroleum products by preventing the loading of mechanical impurities.

Fig, 1 shows a separator, a longitudinal section; FIG. 2 is a section A-A in FIG. 1,

The separator consists of a housing 1 with a diameter D, having a bottom 2 and a crush of 1, 3, nozzles 4 for supplying oil-containing water, 5 nozzles for withdrawing oil products, and nozzles 6 liters of filtrate drain.

Cylindrical partitions 7-10 are concentrically arranged in the housing with the formation of cavities. With a shelf sump 11, collecting filtrate 12, iltra with cavities 13 and 14 and the central cavity 15. At the bottom of the filter an inlet 16 is made for passage from the sump 11 into the central cavity 15 The partition 8 is hermetically attached to the bottom of the filter, and its upper edge is located at a distance H from the cover of the housing; The partition 9 is installed in the cavity of the filter, tightly attached to the housing cover and does not reach the bottom of the filter for a distance H,

A coalescing load of finely granulated glass with electrostatic properties is placed in the cavity l4 of the filter, and the coalescing load from is placed in cavity 13. coarse-grained polymer with oleophilic surface properties.

Above the settling tank 11 and the cavity 12, the oil collectors 17 and 18 are located. The bulkhead 9 has an oil collector

19. The settler is made in the form of shelves

20, In the lower part of the body, between the settling tank 11 and the cavity 15, a flow swirler 21 is placed with a collection of 22 mechanical impurities,

To the bottom 2 are attached nozzles 23 for draining sludge from the sump 11.

The separator works as follows.

Water containing petroleum products and mechanical impurities enters the separator through nozzles 4. During its movement between the shelves 20 of the settling tank 11, all particles of the petroleum product Q having a flow rate higher than that of the flow rise are extracted from it by the action of Archimedes force.

The recovered oil product is collected in the oil collector 17 and then through the branch pipes 5 the oil product is discharged from the separator.

Water with the remaining oil in it enters the swirler 21 of the stream. Having passed the tangential channels of the swirler, it acquires a rotational motion.

From the swirler 21, the rotating fluid flow enters the central cavity 15. During the screw movement of the fluid through the cavity 15 5, the flow is divided into light, intermediate and heavy phases. Oil particles, light phase, concentrated in the center of the stream. Particles of mechanical impurities, in-Q l with a hard phase, are concentrated on the walls of the cavity 15.

Water occupies an intermediate position. The water also contains particles of oil and mechanical impurities, the density of which is close to the density of water.

When leaving the cavity 15, the particles of oil product, by this time already coalesced and having acquired a large lifting force, float into the oil tank 19, and the particles of mechanical impurities settle into the mech collector 22.

From the cavity 15 comes the water, largely purified from mechanical impurities and coarse fraction of petroleum products. The remaining finely dispersed oil product together with water forms a dilute oil-in-water emulsion (m / v). Emulsions of this type have a very high stability, i.e. the ability to maintain its aggregative state for a long time (do not exfoliate).

The stability of diluted emulsions m / v is due to the presence on the surface of petroleum particles of an electrical double layer consisting of a layer of oriented polar molecules.

five

0

five

0

314

Moreover, according to Ken's rule, the positive charge of the molecule is oriented towards the dispersion medium, i.e. water.

Like charges repel each other, which prevents coalescence of oil particles.

In order to successfully carry out the purification process of weakly concentrated emulsions (oil-containing mixtures) from oil, it is necessary to free the oil particle from the electric double layer.

In the process of passing through a layer of finely granulated glass in the cavity 14 with electrostatic properties (having a negative charge), the oil particles transfer their charge to the load. Due to this, an effective coalescence of small particles into a continuous phase occurs.

Further merging of petroleum products

one

occurs when passing through the load in the cavity 13. Here the process of coalescence is ensured by the oleophilicity of the surface of the loading granules.

A prerequisite for coalescence of oil particles is the laminar flow regime of the mixture.

220 (R t 50, D -) in the download. Sco with

the flow rate in this mode is determined by the equation

V W wholesale 248 (1-P) 2 (h h

de ip d

rp

f

N h

pressure drop across the loading layer; diameter of the loading granules; the granule shape of the load, defined by the ratio of the surface of the ball f UJ and particles f c, having equal volumes

fu

four

loading porosityj loading height, dynamic fluid viscosity.

The condition of equality of the flow rates of the mixture in the cavities 11, 12, 13, 14 and the gaps H and H is also fundamental.

ten

444

The velocities in these cavities are determined through the flow rate of the mixture and the diameter of the cavity by the following equations:

5V - / Q.

Ug P (C | - D)

V - / Q

3 D |)

V - / Q

T (l - Dp

V - Q

Bg JT (D | - D2) a in the gaps H and H by the equations

V q

 Y (hD

20V. Since the sludge and centrifugal separation processes differ only in the nature and magnitude of the operating 25 forces, there is a physical relationship between them, expressed through the factor

15

separation of F

 V.

or fr

V,

D.

 2

This relationship makes it possible in general terms to express the diameters of cavities 11, 12, 13, and 14 of the gravity sediment, as well as the gaps H and H through the cavity 15 of centrifugal separation.

Such a relationship for the diameters of the cavities 11, 12, 13 and 14 is

С „D, / Т а and for gaps Н and Н Фр D 1

+ (n-1) F.

N.

4/1 + (p-1) Fr

where D is the diameter of the central cavity

Fp is the separation factor. At the exit of the cavity 13, the water goes around the partition 8 and through the pipes

6 is removed from the separator. The enlarged oil product floats into the oil collector 18 and then is discharged from the separator through the pipes 5 to drain the oil products.

The economic effect of the proposed separator in comparison with the prototype is achieved due to the increased degree of purification and the resource of coalescing loads before replacement.

514

An increase in the degree of purification is determined by preventing the coalescence of large-dispersion mechanical impurities from being driven by centrifugal force from the oil-water mixture and removed from the oil-water mixture.

In addition, reducing the skidding of mechanical impurities allows it to maintain its porosity sufficiently stably and, accordingly, to prevent the transition from laminar to turbulent flow of the mixture, which significantly affects the deterioration of cleaning.

The implementation of the first-in-charge mixture of small-sized granules, which has electrostatic properties, provides an intensification of the coalescence of small oil particles. Large-granulated loading promotes further coalescence of the oil product and its ascent into the oil tank.

Placing the loads in a free state makes it possible to restore the original properties of the load by removing the back current.

Claims (3)

1. A separator for cleaning ship-based oily water from petroleum products, comprising a housing with a cap and bottom, cylindrical partitions placed concentrically in the hull to form cavities with a floor sump, collecting filtrate, filter with coalescing load and central cavity, and the upper edges of the filter partition are located on distance from the housing lid, and in the bottom of the filter an inlet is made for the passage of purified water from the settling tank into the central cavity, branch pipes for supplying oil 44446 holding water, removal of petroleum products, and filtrate, flow porcher, characterized in that, in order to improve the quality of water purification from petroleum products by preventing the loading of coalescing mechanical impurities, it is equipped with a collection for mechanical Q impurities installed in the bottom part of the housing placed in the cavity of the filter impenetrable cylindrical partition, the upper edge of which is tightly attached to the base of the cor- 5, and the bottom is located at a distance from the bottom of the filter; the flow swirler is placed between the collector and the central inlet. The diameter of each subsequent cylindrical partition from the central cavity and the height from the upper edge of the partitions to the shell edge or from the lower edge to the bottom of the filter are determined from the ratios 5 D. 0 Np   + (p-1) Fr, Fr P 4fl + (p-1) T where Dr, is the diameter of the nth partition J D is the diameter of the central cavity JHp, is the height from the upper edge of the pth partition to the housing cover or from the lower edge to the bottom of the filter; Fr is the separation factor of 100-500. 2. A separator according to claim 1, characterized in that the coalescing load is made of granulated glass with electrostatic properties. 3. A separator according to claim 1, characterized in that the size of the granules of the coalescing load increases along the flow in the filter. (puaZ