EP2015871B1 - Three-phase separator comprising a skimming disc and solid discharge orifices - Google Patents

Description

The invention relates to a separator according to the preamble of claim 1 as from WO 96/34693 is known and a method for three-phase separation with such a separator.

Such separators have been known for a long time. In general, the liquid discharges are provided with so-called peeling discs, in which the effect is exploited that the rotational energy of the incoming liquid is converted into a back pressure in the discharge line. Such peeling discs have proven themselves. In particular, it is possible to vary by throttling the prevailing dynamic pressure and thus to vary the separation zone in the drum or the radius of the separation zone in the drum over a certain range A. It is also known, in particular, to assign paring discs to both fluid outlets.

A well-known three-phase separator is in Fig. 3 shown. If one or both of the two fluid outlets from the drum are assigned a paring disc and the further outlet is nozzle-like, the result is an area delta LP within which the paring disc permits a displacement of the separation zone in the drum by throttling (see, eg, US Pat WO 86/01436 ). Here, on the one hand, the range of displaceability of the separation zone is still relatively low and it is not readily possible to move the separating zone in operation fast enough about the peeling discs. The shift also does not always lead to stable process conditions, since the variation of the throttling of the peeling disk processes directly affects several parameters of the process.

The invention has the object of developing the generic separator such that in a simple manner during operation, a displacement of the separation zone within the drum over a larger radial range is possible, with an improved adjustability of the position of the separation zone should be possible. A method for operating such a separator is also to be proposed.

The invention solves this problem by the subject-matter of claims 1 and 12.

• lediglich an ihrem unteren Ende oder an ihrem oberen Ende eine Drehspindel zum Antrieb der Separatortrommel, welche um einen Gelenkpunkt pendelnd gelagert ist,
• ein Zulaufrohr für ein zu verarbeitendes Produkt,
• zumindest zwei Flüssigkeitsauslasse für eine leichtere Phase und eine schwerere Phase, wobei der Flüssigkeitsauslaß für die leichtere Phase mit einer Schälscheibe versehen ist,
• Feststoffaustragsöffnungen, vorzugsweise im Bereich ihres größten Innenumfangs,
• ein in der Separatortrommel angeordnetes Trenntellerpaket,
• wobei dem weiteren Flüssigkeitsauslaß eine einstellbare Drosseleinrichtung außerhalb der Trommel nachgeschaltet ist, die vorzugsweise eine Ring- bzw. Drosselscheibe aufweist und dazu ausgelegt ist, den Flüssigkeitsradius, bis zu dem sich die schwere Phase in der Trommel erstreckt, durch Veränderung des Austrittsquerschnittes für die schwere Flüssigkeitsphase - also durch Androsselung - zu verschieben.

The invention proposes a separator with an at least one inside or double conical separator drum, which is rotatably mounted only at one of its axial ends and which has a vertical axis of rotation and which further comprises

• only at its lower end or at its upper end a rotary spindle for driving the Separatortrommel, which is mounted oscillating about a hinge point,
• an inlet pipe for a product to be processed,
• at least two fluid outlets for a lighter phase and a heavier phase, the liquid outlet for the lighter phase being provided with a paring disc,
• Feststoffaustragsöffnungen, preferably in the region of its largest inner circumference,
• a separator plate arranged in the separator drum,
• wherein the further liquid outlet is followed by an adjustable throttling device downstream of the drum, which preferably has a ring disk and is adapted to change the liquid radius up to which the heavy phase extends in the drum by altering the outlet section for the heavy liquid phase - So by throttling - to move.

With the help of the invention, in particular improved controllability of the process and in particular an improved controllability of the position of the separation zone, also called E-line results.

It is also possible to compensate for changes in the product quantities (phase ratio) as well as the product quality (in particular density) and still keep the dividing line virtually constant. Nozzle wear can be determined and service life extended.

Throttle devices also on the type in operation non-rotating annular discs are known from the field of solid bowl screw centrifuges known per se - so from the DE 102 09 925 A1 or the DE 102 03 652 A1 , However, the drums of these centrifuges are stored in the region of both axial ends and not oscillating like centrifuges. This results in the difference that the drums of the decanter or solid bowl centrifuges rotate about a defined axis, while the Separatortrommeln Perform a certain precession movement, so that it was assumed that the conditions at the drain ring gap are not constant enough to achieve a defined adjustment of the separation zone between light and heavy phase and a shift of the drainage radius of the heavy liquid phase by means of an adjustable throttle plate. This assumption has not been confirmed. Contrary to expectations, stable conditions also occur at the outlet gap of the separator at the throttle disk. Rather, the throttle disc improves process efficiency as well as fine tuning and process stability.

The separator is suitable for a wide variety of three-phase separation tasks, in particular crude oil processing, in which the crude oil is clarified by solids and water is separated from the crude oil.

The invention also provides a use of a separator according to the invention according to one of the corresponding claims for crude oil treatment in which the crude oil is clarified by solids and water is separated from the crude oil.

The invention also provides a process for the three-phase separation and clarification of a product to be processed in at least two liquid phases and a solid phase, wherein the processing of the product takes place in a separator according to one of the corresponding claims directed to this, wherein for adjusting the separation zone once in operation adjusting the radius of the light liquid phase LP by means of the paring disc and then adjusting the heavy liquid phase (HP) and thus the separation zone by means of the throttle device, preferably the annular disc takes place.

Further advantageous embodiments can be found in the remaining subclaims.

Fig. 1

einen Schnitt durch eine Hälfte einer erfindungsgemäßen, rein schematisch dargestellte Separatortrommel;

Fig. 2

einen Schnitt durch eine weitere erfindungsgemäße, schematisch dargestellte Separatortrommel;

Fig. 3

einen Schnitt durch ein Ausführungsbeispiel eines Antriebesbereiches für eine Separatortrommel nach Art der Fig. 1 bis 3;

Fig. 4

eine Separatortrommel nach dem Stand der Technik; und

Fig. 5a-c

eine mehrteilige Tabelle zur Veranschaulichung der Wirkung der Erfindung.

The invention will be described with reference to an embodiment with reference to the drawings. It shows:

Fig. 1

a section through one half of a separator drum according to the invention, shown purely schematically;

Fig. 2

a section through another inventive separator drum shown schematically;

Fig. 3

a section through an embodiment of a drive portion for a separator drum in the manner of Fig. 1 to 3 ;

Fig. 4

a separator drum according to the prior art; and

Fig. 5a-c

a multi-part table to illustrate the effect of the invention.

Fig.1 to 3 each show separator drums 1, which have a vertically oriented axis of rotation at the radius r ₀ .

The Separatortrommeln 1 are each set to a rotary spindle 2, for example, the type of Fig. 4 driven directly or via a belt (not shown here) or otherwise (eg a gearbox) is. The rotary spindle 2 may be designed conically in its upper peripheral region.

The rotary spindle 2 is mounted with at least one or more bearings 3 on one side of the drum - here below the drum - oscillating and therefore describes in operation due to residual unbalance unlike a decanter a new axis adjusts a kind of precession movement around the vertical r ₀ ( please refer Fig. 4 in which the inclination angle α is shown).

In addition to this type of construction, constructions are also known in which a lower drum is quasi "suspended" on an upper rotary spindle. Again, however, the drum is rotatably mounted oscillating only at one of its ends or subsequent to one of its axial ends.

The separator drum 1 has a feed pipe 4 for a product P to be hurled, to which a distributor 5 adjoins, which is provided with at least one or more outlet openings 6, through which incoming centrifugal material (crossed hatching) into the interior of the separator drum 1 and the Rising channel 7 of the plate package can be passed. A feed through the spindle e.g. from below is also possible.

Here, the construction is chosen such that the outlet openings 6 below a riser channel 7 in a plate package 8 (outer diameter at reference numeral 8) of conically shaped separating plates 9 are. At the top, the plate package 8 of a Sheath plate 17 completed, which has a larger diameter than the plate package.

Within the separating plate pact, and preferably within the rising channel 7, during operation with a corresponding rotation of the drum at a certain radius r _E - the Emulionslinie or dividing line (also called E line) - forms a separation zone between a lighter liquid phase LP (hatching from the left bottom right top) and a heavier liquid phase HP (hatching to the lower right).

The lighter liquid phase LP (light phase) is conducted at an inner radius r _LP with the aid of a paring disc 10 (also called a gripper) from the drum. With Hilde of the dynamic pressure created by the rotational energy of the fluid, the paring disc acts like a pump. The peeling disk is downstream of a valve 18 for throttling, for example, outside the separator in its downstream discharge.

On the other hand, the heavy liquid phase HP flows around the outer circumference of the disc plate 17 through discharge passage 11 to a liquid outlet 12 at the upper axial end of the drum 1 (radius r _HP ).

In that regard, the constructions of the correspond Fig. 1 to 3 , They are also providable with the same drive devices.

To Fig. 3 flows the heavy phase HP at the liquid outlet 12 overflow from the drum.

The constructions of the invention Fig. 1 and 2 are different than the construction of the Fig. 3 provided in the region of the liquid outlet 12 with an adjustable throttle device 13, by means of which the cross section is variable at the liquid outlet.

In order to realize this throttle device 13 structurally in a simple manner, it is proposed according to the type Fig. 2 and 3 to arrange in the axial direction above the liquid outlet 12 outside the drum 1, a kind of annular or throttle plate 19, which is arranged and formed spaced from the at least one liquid outlet opening, wherein the position of the annular disc 19 to the at least one Outlet opening is variable. The disc may have a flat surface or be provided with grooves, for example. The surface of the annular disc is preferably - but not necessarily - aligned perpendicular to the drum axis.

Preferably, the annular disc 19 is e.g. axially displaceable or arranged pivotably on one of its peripheral edges and the annular disc is associated with a drive which is adapted to change the distance between the preferably stationary during operation annular disc 19 and the outlet opening 12.

Preferably, the annular disc 19 is designed to be stationary during operation and does not rotate with the drum 1 with.

Between the annular disc 19 and the outlet openings 12 such a gap 20 is formed, which is flowed through by the effluent from the drum heavy liquid phase HP, wherein the width of the liquid gap is variable.

Both by throttling the paring disc and by adjusting the throttle device or here the gap width of the gap 20 by moving the annular disc 19, the radius of the E-line can be moved within the drum by a certain range.

Here, the double conical drum in the region of its largest diameter solid discharge nozzles 21, which serve for the continuous discharge of solid particles S from the drum. This embodiment is preferred. Embodiments without an additional solids discharge are also conceivable.

The original assumption that not enough stable conditions at the exit slit 20 form when using a movable annular disc 19 on a single-sided or cantilevered drum due to the significant precession, since the gap 20 due to the precession has no constant gap width, has not come true (see also the tables of the Fig. 5 ).

Rather, the displaceable annular disc leads to a significant improvement in the adjustability of the emulsion line (E-line) and to a better controllability and controllability of the process. This also results in an enlarged adjustment range of the separation zone.

In that regard, in turn, the designs of the same Fig. 1 and 2 ,

The outlet openings 12 may have a round shape in the manner of bores or may be e.g. Wedge-like or step-like widening from the inside out, which increases the control capability in different cases .. It could also be a tube placed in the outlet openings, which would have the advantage that the liquid flow does not attach to the drum.

To Fig. 2 the liquid outlet is preceded by a kind of Hydrohermitikringkammer 14.

This consists of a liquid outlet in the drum upstream disk 15 which extends from the outer periphery of the paring disc 10 to the outside and having a maximum circumferential radius which is greater than the largest radius to which the outlet openings 12 extend. The standing still, non-rotating (shutter) disc 15 is in turn connected upstream of the drum 1, a kind of annular disc 16 as the first weir, which extends from the inner periphery of the drum cover of the drum 1 inwardly and whose inner radius is smaller than the largest Radius to which the disc 15 and the outlet openings 12 extend, so that in the region between the annular disc 16 and the outlet openings 12 (as 2nd weir) on the inner circumference of the drum cover of the drum 1, the Hydrohermitikringkammer 14 is formed.

This chamber prevents the uncontrolled escape of gases or steam from the drum through the outlet openings 12 or labyrinths or other gaps or the like, which would cause a short-term instability in the region of the emulsion line - separation zone -.

For pressure equalization vertical holes 22 which extend through the disc-shaped projection of the paring disc 10 and are not in operative connection with the drainage channel in paring disc may be provided.

• Die verbesserte Kontrolle bzw. Einstellbarkeit des Radius rE der Emulsionslinie - auch Trennzone oder Trennlinie genannt - erhöht in bedeutsamem Umfang die Optimierbarkeit, die Stabilität und die Feinabstimmung des Prozesses im Dreiphasen-Separationssystem.

In practice, the invention has the following effects:

• The improved control of the radius rE of the emulsion line - also called separation zone or separation line - significantly increases the optimizability, stability and fine-tuning of the process in the three-phase separation system.

Assuming that the throttle device 13 with an orifice plate 19 which is adjustable, the discharge radius of the heavy liquid phase can adjust by 10 mm and that the paring disc can exert an additional pressure drop of 100,000 Pa, there is the following possibility of setting the E Line or the maintenance of a stable E-line with different tightness rates (K) (see the tables of Fig. 5 ).

The throttling device 13 alone can achieve an adjustability of the discharge radius of the heavy liquid phase of about 336 to 384 mm (ie 48 mm) or a compensation of the density variance (K) of 0.884 to 0.915 (0.031), because either by reaction to shifts or in product changes by changing the gap width of the gap 20 counteracted a displacement of the separation zone to keep them at a constant radius as possible to keep the process stable.

By contrast, the peeling disk 10 alone can achieve an adjustment of the radius of the dividing line of 360 to 392 mm (32 mm) or a compensation of the density change (K) of 0.878 to 0.900 (0.022).

Combined, the throttling device 13 and the peeling disk 10 can achieve an adjustment of the separating zone or the radius of the E-line of 336 to 414 mm (corresponding to 78 mm) or a density ratio variance (K) of 0.863 to 0.915 (0.052).

This shows impressively that it is not only possible with the combination of paring disc 10 and throttle 13 and the Feststoffaustragsdüsen 21 (which a discharge system, for example, with baffles or the like.) Is to adjust the e-line over a large area, but that it is also possible to keep the E-line constant especially easy if the composition or property of the material to be centrifuged changes, or if the machine characteristics change due to nozzle wear. here the discharge cross section for the solid phase and thus the discharge amount of the solid phase.

Will by type of FIG. 2 provided a hydrohermetic chamber 14, it is possible to prevent steam or gas (eg hydrocarbons and / or water or oil vapor) from leaking from the liquid, regardless of the process temperatures, so that there is the advantage that, in particular by Water vapor neither the separation or separation efficiency in the plate stacks nor the position of the E-line radius is affected.

It is also possible, a separate and independent water supply into the drum (not shown here, feasible, for example, by a concentric supply pipe within the supply pipe 4 for the product and further through the manifold into the drum) to provide in the three-phase separation - without a To exert additional hydraulic load on the stack of plates - to ensure that there is always a sufficient back pressure at the gap 20. If, on the other hand, the gap were not completely traversed, there would possibly be an uncontrolled shift in the e-line.

The discharge volume flow through the gap 20 is preferably observed and possibly also measured in order to prevent such dry runs and to minimize the volume of water to be added as much as possible.

In the invention, it is also possible and particularly advantageous to measure the flow rate of the product to the centrifuge as well as the flow rates at the effluents via the paring disc 10 and through the gap 20 at the throttle device 13, wherein the rate of discharge of solids through the solids discharge 21st from the differences of these sizes can be determined.

The nozzle discharge capacity may be initially determined theoretically based on the machine design and drum rotation speed. This capacity is hereinafter referred to as "nominal" capacity or derivative rate.

The difference between the nominal and the "measured" discharge rates of the solids nozzles gives information about the operating states of the nozzles.

If the "measured" bleed rate is greater than the nominal rate, the nozzles 21 will show wear and a period of time within which it is advisable to repair the solids discharge nozzles 21 may be indicated. This is advantageous because it is possible to maximize the time to change nozzles.

If the measured "drain rate" is less than the nominal rate, one can conclude that one or more of the solids discharge nozzles 21 are clogged.

The system may be configured to automatically correct the effect of nozzle wear when determining whether the solids discharge nozzles are clogged or not.

Finally, it is also possible to create a kind of expert system for process optimization and control with the aid of the separator drum according to the invention.

The pressure drop across the throttle device (at the gap 20) depends on the flow rate or quantity and the size of the gap 20. The pressure drop over the paring disc 10 depends on the flow rate and the throttling pressure on the valve 20 of the paring disc. The pressure drops affect the discharge rates of the heavy and light phases. Combined and considered individually, the discharge line radii also influence the position of the E-line.

Since it is clear how the heavy and light discharge radii are affected by the pressure drop across the gap 20 and the paring disc and how this affects the E-lines, an improved separator control and regulation system can be provided.

Thus, from the fact that the radius of the E-line is particularly small, the user can conclude that a greater proportion of heavy phase is in the light phase and vice versa.

If the emulsion is not separable, an emulsion layer has built up within the centrifuge.

By making suitable adjustments to the settings at the gap 20 and / or at the paring disc, it is possible either to prevent the formation of the emulsion layer or to divert it into the heavy or the light liquid discharge, before the process becomes unstable or a poorer clarification takes place or before the process becomes uncontrollable.

With an online expert system, a stable separation process can be maintained although fluctuation in the product feed rate and composition may occur or density fluctuations of the heavy and / or lighter liquid phases LP and HP. Such effects occur e.g. in natural products such as fish oil or in the treatment of crude oil (separation of water from the crude oil) or in the treatment of water (in particular separation of oil residues from the water).

By supplementing the online expert system with an online measurement of the flow rate and / or the product flow rate, it is possible to calculate the feed density or finally measure the density directly.

A correction of the flow rate of the solids can be performed by measuring the solids content, since the solids density is a relatively constant parameter.

By measuring the discharge rate of light phase and the amount of flux, the light phase density and finally the density can be measured directly.

From the densities, the inflow and outflow rates of the heavy and light phases can be determined.

From all these values conclusions can be drawn which allow to optimize the separation process by means of adjustments at the gap alone and / or by suitable throttling of the paring disc.

This simple expert system can be supplemented by an online measurement of the exact heavy phase composition and the light phases. Neither the heavy nor the light phases typically have a polarity which would make measuring the volumetric concentration easy.

reference numeral

Separatortrommeln

1

spindle

2

camp

3

supply pipe

4

distributor

5

outlet openings

6

rising channel

7

Disc stack

8th

separator disc

9

peeling disc

10

Waterway

11

liquid outlet

12

military equipment

13

Hydrohermitikringkammer

14

baffle plate

15

washer

16

separating disk

17

control valve

18

washer

19

gap

20

Solids discharge nozzles

21

drilling

22

vertical

R0

angle

α

lighter fluid phase

LP

heavier liquid phase

HP

Claims (19)

1. A separator with an at least inwardly singly or doubly conical separator drum (1) which is mounted rotatably at only one of its axial ends and which has a vertical axis of rotation and which, furthermore, has the following:

   a) only at its lower end or at its upper end, a rotary spindle for driving the separator drum, which rotary spindle is mounted oscillatingly about an articulation point (G),

   b) an inflow pipe (4) for a product to be processed,

   c) at least two liquid outlets for a lighter phase (LP) and a heavier phase (HP), the liquid outlet for the lighter phase (LP) being provided with a stripping disk,

   d) preferably, solid discharge ports in the region of its largest inner circumference,

   e) a separation plate stack arranged in the separator drum,

   characterized in that

   f) the liquid outlet (12) of the heavier phase (HP) is followed outside the drum by a settable throttle device (13) which has an annular disk (19) and is designed for displacing the liquid radius R(HP), up to which the heavy phase extends in the drum, by a variation in the outflow cross section for the heavy liquid phase, that is to say by throttling.
2. The separator as claimed in claim 1, characterized in that the annular disk (19) is arranged in the axial direction, above the liquid outlet (12) outside the drum (1).
3. The separator as claimed in one of the preceding claims, characterized in that the annular disk (19) is assigned a drive device, and in that the annular disk is arranged axially moveably, in particular displaceably and/or pivotably, so that the distance between the annular disk (19), stationary during operation, and the outflow port, that is to say the gap width of an annular gap (20), is variable.
4. The separator as claimed in one of the preceding claims, characterized in that the annular disk (19) is designed to be nonrotating during operation.
5. The separator as claimed in one of the preceding claims, characterized in that the solid outflow ports are designed as nozzles (21) which are designed for the continuous discharge of solid particles from the drum (I).
6. The separator as claimed in one of the preceding claims, characterized in that the solid outflow nozzles (21) can be closed by means of a piston slide.
7. The separator as claimed in one of the preceding claims, characterized in that the solid outflow nozzles (21) contain nozzles and a piston slide.
8. The separator as claimed in one of the preceding claims, characterized by a further feed pipe extending into the drum, for a liquid, such as water, as an addition to the product to be processed.
9. The separator as claimed in one of the preceding claims, characterized by at least one or more sensors for measuring the product flow rates at the inflows and/or outflows.
10. The separator as claimed in one of the preceding claims, characterized in that the liquid outlet (12) for the heavy liquid phase and the throttle device (13) are preceded by a hydrohermetic annular chamber (14).
11. The separator as claimed in claim 10, characterized in that the hydrohermetic annular chamber (14) consists of a retaining disk (15) which precedes the liquid outlet (12) within the drum and which extends outwardly from the outer circumference of the stripping disk (10) and which has a maximum circumferential radius which is larger than the maximum radius up to which the outflow ports (12) extend, the retaining disk being preceded by an annular disk (16) which extends inwardly from the inner circumference of the drum cover of the drum (1) and the inner radius of which is smaller than the maximum radius up to which the retaining disk (15) and the outflow ports (12) extend, so that the hydrohermetic annular chamber (14) is formed on the inner circumference of the drum cover of the drum (1) in the region between the annular disk (16) and the outflow ports (12).
12. A method for the three-phase separation and clarification of a product to be processed, into at least two liquid phases and one solid phase, characterized in that the processing of the product takes place in a separator as claimed in one of the preceding claims, and, to set the separation zone, a setting of the radius of the light liquid phase (LP) by means of the stripping disk (10) and then a setting of the heavy liquid phase (HP) and consequently of the separation zone by means of the throttle device (13), in the form of the annular disk (19), taking place once during operation.
13. The method as claimed in claim 12, characterized in that the separation zone is kept at a constant radius by means of a regulating method as a function of the product feed quantity and/or characteristic.
14. The method as claimed in claim 12 or 13, characterized in that the flow quantities in the product feed line into the drum and the product discharge line out of the drum are determined, in particular measured, at the stripping disk and the throttle device, and in that the flow quantity of solid is determined from the difference between these variables.
15. The method particularly as claimed in claim 12, 13 or 14, characterized in that a conclusion as to a variation in the state of the solid discharge nozzles is drawn from a variation in the determined flow quantity for the solid phase, an increase in the flow quantity pointing to a wear of the nozzles, and a decrease in the flow quantity pointing to a blockage or contamination of the nozzles.
16. The method as claimed in claim 15, characterized in that, in the event of the formation of an emulsion, the separation zone is displaced as a result of the adjustment of the stripping disk and of the throttle device, in such a way that the emulsion is discharged through the stripping disk or the gap at the throttle device.
17. The method as claimed in one of claims 12 to 16, characterized in that the solid content of the product conducted into the separator drum is measured.
18. The method as claimed in one of claims 12 to 17, characterized in that the outflow volume of the light liquid phase is determined, in particular measured.
19. A use of a separator as claimed in one of the preceding claims for crude oil treatment, in which the crude oil is clarified of solids and water is separated from the crude oil.

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