SK52499A3 - Device to separate two-phase liquid mixtures - Google Patents

Abstract

The separator (10) has a twisted inlet imparting spin to the fluids. The separator (10) removes a small proportion of light fluid from a larger proportion of a heavier fluid which may also incorporate some sludge, from a mixture of e.g. oil and water. The separator has a separator basin (12) for fluid which is retained to a minimum depth by an overflow pipe (18). The basin also has an inlet pipe (14), and outlet pipe (16) and a tubular light fluid collector (20). The mixture enters through the inlet pipe and is released into the collector where the heavier fluids and sludge descend to the lower sector (26) within the separation basin. A separation panel (30) within the collector curves from the collector wall (22) to the collector axis (24) to form a spiral intermediate space (36), and an outer intermediate space (38) against the collector wall. The wall and separation panel each have an upper edge (40, 42) which is at least in part higher than the lowest fluid level. The inlet pipe funnels tangentially through the collector wall into the outer intermediate space at ca. the same height.

Description

Separator for separating biphasic liquid mixtures

Technical field

The invention relates to a separator for separating biphasic liquid mixtures comprising a smaller proportion of light liquid and a larger proportion of heavy liquid, optionally containing sludge, such as oil-contaminated and optionally sludge containing water.

BACKGROUND OF THE INVENTION

A separator of the kind mentioned above is known, for example, from WO-93/07946. An inlet pipe for the mixture to be separated and an outlet pipe for the heavy liquid, largely cleaned of the light liquid and optionally of the sludge, are connected to the collecting tank for collecting the light liquid and possibly the sludge. The liquid contained in the separation tank extends at least to the lowest level of the liquid determined from the overflow from the separation tank to the outlet pipe. A light liquid collector is provided within the separator tank and has a substantially tubular vertical wall (lining). From the inlet pipe, the mixture to be separated is introduced into the collector interior. Heavy liquid and possibly sludge from the lower region of the collector reach the lower region of the separation tank. Inside the collector there is a vertical separating wall which coils in the helical threads from the collector wall to the collector axis, successive threads of the separating wall mutually defining the helical interspace and the outer outer thread of the separating wall defining the outer wall together with the separating wall. It has been shown that the separator known from WO-93/07946 (as well as other separators of this kind) does not achieve a sufficient and satisfactory separation of the biphasic liquid mixture into a light liquid and a heavy liquid, especially as regards oil-contaminated and possibly sludge containing water.

A separator of the kind mentioned above is also known, for example, from GB-A-2167698. Even with this separator, it is known that a vertical arrangement is arranged inside the collector

- the separating wall does not extend to such an extent that it spirals in the helical turns from the pantograph wall to the pantograph axis. No spiral intermediate space is defined, but between the separating wall and only a portion of the collector wall an outermost intermediate space and this also only in the form of a segment (no entire circumference) of the hollow cylinder (no spiral). An inlet pipe extends into the interspace through the collector wall and approximately tangentially thereto, said interspace having a horizontal-radial clear width which corresponds to the horizontal width of the inlet pipe. On the other hand, the collector with the separating wall disposed therein is still fully immersed in the liquid contained in the separating tank, i.e. the separator wall. j. the collector wall and the separating wall can never have an upper edge that is higher than the lowest liquid level - therefore oil separation and oil drainage can not be efficiently effected at low feed rates: If only small amounts of liquid flow over a longer period of time, With a high proportion of oil, the oil layer would be very high and the cleaning space containing the mixture to be divided is correspondingly smaller, so that the cleaning performance decreases. Although the sludge can also be collected (also collected) in the lower region of the separation tank, it has not been described at all that this region has been deliberately created as a sludge collection space and made accordingly.

DE-A-2851213 discloses a current entering tangentially from the inlet pipe into the collector. In the collector of this device, this current runs helically downward, i.e.. j. about the vertical axis and not spirally horizontally to the axis. Therefore, no separating wall is formed inside the collector.

A collector is known from WO-89/07971, in which the inflow pipe flows through the collector wall and approximately tangentially thereto into the collector. This collector does not exhibit any partition wall, the successive turns of which would define a spiral interspace in each other, into the outer outer region of which the inlet pipe could enter.

From the EP-A-0199495 a collector of the kind initially defined is known, i. j. a collector having a separating wall but with the exception that the collector is closed in addition to the upper and lower axial effluent area: In this way, the heavy liquid and possibly sludge cannot exit the entire lower region of the collector but only from the collector.

-3the area of its lower axial outlet downwards, as a result of which deposits may form at the bottom of the pantograph, which can clog the pantograph and can only be removed by special cleaning. It is stated that with this collector the linear flow rate is constant, which means (as shown in the figures) that along the separator wall threads, the horizontal-radial clearance width between the separator wall threads is constant as in the Archimedes spiral. Without further explanation in the text, a single cross-sectional picture shows the varying clear width of the interspace, but it is in this respect that this picture is technically manifestly incorrect - the section shown does not correspond to the corresponding floor plan, in which the clear width is shown as constant. The upper edge of the separator wall of this collector loses its height along its threads in the direction from the collector wall to its axis to convey heavy particles to the bottom center and there to the lower axial outflow, while the light particles to the top outlet center. For this, however, the pantograph must always be filled during its operation: However, since it is closed from all sides, its operation requires that significant, inflow quantities be maintained. If the collector is intended to be used in the paper industry, this flow rate is sufficient and can be achieved by the pressure of the pump, on the other hand, for a two-phase liquid mixture which may contain sludge, as with oil contaminated and possibly sludge containing water. The collector, which would be open up and down while being arranged inside the separation tank, is not indicated or indicated.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a separator which, in comparison with the prior art, allows an improved separation of the biphasic liquid mixture into a light liquid and a heavy liquid, especially in the case of oil contaminated and possibly sludge containing water.

SUMMARY OF THE INVENTION

This object is solved according to the invention by a separator for separating biphasic liquid mixtures containing a smaller proportion of light liquid and

-4-greater proportion of heavy liquid, where appropriate also containing sludge, such as oil-contaminated and possibly water-containing sludge, with a separating tank for collecting light liquid and possibly sludge, an inlet pipe for the mixture to be separated and a heavy pipe a liquid largely cleaned of light liquid and optionally sludge, the separating tank being designed to contain liquid at least to the lowest liquid level determined from the effluent from the separating tank to the drain pipe, and within the separating tank by an arranged liquid collector, having a substantially tubular vertical wall, the mixture coming from the inlet pipe to the interior of the collector and from the lower region of the collector to the heavy liquid and possibly sludge to the lower region of the separating tank, and wherein a vertical separating wall is arranged inside the collector; molded ak o the cut-out of the straight surface that results from the vertical forming ends and the horizontal spiral control curve and extends substantially from the collector wall to the helical threads along the collector axis, and successive threads of the separating wall define the spiral interdigital interspacing The separating wall defines, together with the collector wall, the outermost intermediate space in which both the collector wall and the separating wall have one upper edge which at least in the region of the outer outer intermediate space lies higher than the lowest liquid level, the inlet pipe extends over the collector wall approximately to the collector outer outer space, and the outer outer space at least in the region of the inlet opening of the inlet pipe has a horizontal-radial clear width which approximately corresponds to the horizontal width of the inlet pipe.

The separating wall may be less wettable with light liquid on the outwardly facing side of its turns than on the inwardly facing side of its turns and the collector wall.

The separating wall may be coated, coated or coated with a light-liquid-repellent material on its outwardly facing side.

The separating wall and the collector wall may be coated, coated or coated with a light liquid wettable material on their inwardly facing sides.

In a preferred embodiment, the separator has a variable, preferably periodically variable, horizontal-radial clear width of the interspace between the threads of the separating wall along the threads of the separating wall.

In a separator according to the invention, the upper edge of the separating wall along its threads in the direction from the collector wall to its axis may lose height.

In the separator according to the invention, the inlet pipe and the outlet pipe may be substantially arranged opposite each other, and the lower edge of the collector wall may lie in certain regions in a single inclined plane facing the vertical portion of the lower region of the separator tank.

The exhaust pipe is arranged centrally and axially in the collector, the upper opening of which is approximately at the level of the lowest liquid level, and which extends to the oil drain space, while the heavy liquid drain tube leads to or from the lower region of the oil drain space. near the outlet opening of the drain pipe and from the upper region of the oil drain chamber, the light liquid overflow leads to an oil tank.

The take-off pipe may be flexible or extendable and is arranged on a floating body adapted to float on liquid.

The oil-pumping space may be arranged inside the separator tank and the collector inside the oil-pumping space.

The oil-pumping space may be arranged in a separator tank and form an immersion wall that extends up to the lowest liquid level in front of the outlet orifice of the drain pipe and sinks down into the liquid to limit the inflow

-6 liquids from the separation tank to the outlet pipe for the amount of liquid from the bottom area of the separation tank.

In the upper region of the immersion wall, a connection may be provided to return the liquid to the collector near the lowest liquid level.

The lower region of the separation tank can be designed as a sludge collection space.

The light liquid from the heavy liquid is separated by the biphasic fluid mixture entering tangentially into the collector and spirally directed thereto, especially if the biphasic fluid mixture is an oil contaminated and possibly sludge containing water.

This coalescence and separation effect as such is about. i. known from the so-called cyclones. However, it is believed that a particularly effective separation achieved in the device according to the invention achieved in comparison with the prior art could be explained essentially as follows:

Conduction of the current to the collector axis at the corresponding helically tapering intermediate space in which the current is conducted causes a gradual acceleration of the current which contributes to the coalescence of the light liquid droplets.

By conducting the current through the preferably periodically tapering and expanding intermediate space along the threads of the separating wall, pulsating pressure ratios are achieved. a pulsating flow that further contributes to the coalescence of light liquid droplets.

By advantageously using the different wettable materials of the collector separation wall, phase separation is particularly advantageous.

Due to the fact that the separating wall loses its height at its upper edge towards the center, the light liquid that is peeled off and washed away in the center can be removed in the middle by an arranged exhaust pipe. The residual amounts of water can also drain off. The take-off pipe leads to an oil-pumping space in which the light liquid rises while the heavy liquid drops and leads from below to a drain pipe. Due to differences in density of liquids in different interconnected spaces, the light liquid rises in the oil

-7 an elevated liquid level so that the light liquid is drained through the overflow and leads to an oil tank.

The asymmetrical arrangement of the bottom part of the separating wall will allow the washed-out particles, micelles and droplets of light liquid that eventually remain in the downward heavy liquid to exit at the inlet side of the inlet pipe, i. j. as far away as possible from the drain pipe, so that they do not get into the drain immediately but remain in the separator and can be captured.

In the case of prolonged operation under the influence of the ring flow in the collector, the ring flow in the separator tank also arises. Thus, the most recent washed-out particles, micelles and droplets can be retained by the immersion wall and brought back from the upper area to the collector.

In the following, an exemplary embodiment of the present invention will be described in more detail by means of a drawing, from which other features and advantages of the invention may be recognized. In the figures, corresponding parts are designated with the same reference numerals.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a schematic representation of an exemplary embodiment of a separator according to the invention in axial vertical section corresponding to line B-B of FIG. 2; and

Fig. 2 is a schematic representation of the separator of FIG. 1 in a radial horizontal section corresponding to line A-A of FIG. First

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1 and FIG. 2, which is shown in total and denoted 10 as an exemplary embodiment of a separator according to the invention, is intended for collecting light liquid and possibly sludge which are present in smaller quantities in a larger quantity of heavy liquid and are entrained by it. The biphasic liquid mixture, which optionally also contains sludge, is, for example, oil-contaminated and

Or 8 sludge containing water, such as is produced, for example, on roads and highways and is drained into the sewer.

The separator 10 comprises a separation tank 12 with an inlet pipe 14 for supplying the mixture to be separated and with an outlet pipe 16 for discharging

I heavy liquids (e.g. water), largely free of light liquids (e.g. oil) and possibly sludge. The inlet pipe 14 and the outlet pipe 16 are arranged substantially diametrically opposed on the separator tank 12, which is designed essentially as a hollow cylinder with a vertical axis. The height of the effluent 18 determines, by its height (not shown), the lowest level of the liquid in the separating tank 12.

In the separator tank 12 is provided a light liquid collector 20 having a substantially tubular vertical wall 22 about a substantially vertical axis 24. From the inlet tube 14, the mixture enters the interior of the collector 20 by opening the inlet tube 14 through the wall 22 of the collector 20 and approximately tangentially thereto into the collector 20. From the lower region 26 of the collector 20, the heavy liquid and eventually the sludge get into the lower region 28 of the separation tank 12, which is expediently designed as a sludge collection space.

Inside the collector 20 there is a flat separating wall 30 which, starting from the wall 22 of the collector 20, is wound substantially up to the axis 24 of the collector 20 by helical threads. More precisely, the separating wall 30 is shaped substantially as a cut-out of the linear surface which results from FIG. 1 by broken lines 32 of the vertical forming ends shown in FIG. 2 of the horizontal helical control curve 34 shown in succession. The successive turns of the separating wall 30 define the spiral interspace 36, while the outer outer thread of the separating wall 30 defines, together with the collector wall 22, the outer outer interspace 38 into the collector 20. Correspondingly, the outer outer space 38 of the collector 20, at least in the region of the inlet opening 70 of the lance 14, has a horizontal-radial clear width which approximately corresponds to the horizontal width of the lance itself.

The upper edge 40 of the collector 20 wall 22 and the upper edge 42 of the separating wall 30 (compare with FIG. 2) both lie, at least in the region of the outer outer interspace 38, higher than the lowest liquid level determined by the drain.

From the wall 22 of the collector 20 towards its axis 24, the upper edge 40 of the partition wall 30 loses its height along its threads. An exhaust pipe 44 is arranged centrally-axially in the collector 20, the upper opening 46 of which is approximately at the level of the lowest liquid level. This take-off pipe 44 is made flexible or extendable and is arranged on a floating body adapted to float on a liquid, in such a way that the upper opening 46 of the take-off pipe 44 is always close to the liquid level on the collector axis 24 (ie also near the tip of the inverted conical). shape formed by the upper edge 40 of the separating wall 30 of the collector 20).

The take-off pipe 44 leads from the collector 20 to the oil removal chamber 48. From the lower area 50 of the oil removal chamber 48, the heavy liquid drain pipe 52 leads to and substantially the height of the outlet orifice 54 of the drain pipe 16. From the upper area 56 of the oil removal chamber 48, the light liquid overflow 58 leads to the oil tank 60.

The lower region of the wall 22 of the collector 20 is generally lower than the separating wall 30, and is generally in the form of a truncated cone with a lower edge 62 that lies in an inclined plane 64. This is arranged and inclined in such a way that the lower opening 66 of the collector 20 defined by the lower edge 62 is facing approximately vertically below the inlet pipe 14 of the lying part 68 of the lower region 28 of the separation tank 12.

In the exemplary embodiment described herein, the collector 20 and the oil-pumping space 48 are arranged separately within the separator tank 12, the collector 20 being located outside the oil-pumping space 48. The oil pumping space 48 is designed to form an immersion wall in the separator tank 12 in front of the outlet opening 54 of the drain pipe 16. Such an immersion wall serves itself in a manner known per se to limit the inflow of liquid from the separation tank 12 to the outlet pipe 16 to the amounts of liquid from the bottom.

The submerged wall, respectively. for this purpose, the oil-withdrawing chamber 48 extends upwards above the lowest liquid level and downwards into the liquid.

In another, non-described, exemplary embodiment, they may be

The oil removal space is arranged inside the separation tank and the collector inside the oil removal space, and then a separate immersion wall is formed.

In both cases (i.e., in the oil-pumping space acting as an immersion wall, or in a separate immersion wall), a connection (not shown) may be formed (not shown) to return the liquid to the collector in the upper region of the immersion wall near the lowest liquid level. This connection can be made, for example, as a small hole with a pipe connected at the top of the immersion wall and essentially serves to make use of differences in specific gravity caused by liquid level differences in different parts of the device to remove the most recent flooded particles, micelles and droplets. liquids from the exiting heavy liquid and for their return to the collector.

In order to promote the lysing of the washed-out particles, micelles and droplets of the light liquid, the partition wall 30 is made on both its surfaces, i. j. on both sides, with different quality. On the outwardly facing side of its threads, the partition wall 30 is formed as less wettable with a light liquid than on the inwardly facing side of its turns. Also, the collector wall 22 on its inner side is made better wettable than the separating wall 30 on its outward facing side - because the collector wall 22 forms on its inner side an outward extension and the outer end of the threads of the separating wall 30.

To produce the desired surface quality, the separating wall 30 on its outwardly facing side is coated, coated or coated with a light-liquid-repellent material, while the separating wall 30 and the collector wall 22 are coated, coated or coated on their inwardly facing sides. which is well wettable with a light liquid. For example, the light-liquid-repellent material may be an oil-repellent polymer, such as

-11 is polytetrafluoroethylene, polyethylene, polypropylene, and the like, while the light liquid wettable material may be, for example, an oil-tolerant or oil-borne polymer. better tolerates oil such as polyamide, epoxy resin and the like.

In addition, it has been shown that the coalescence of the washed-out particles, micelles and droplets of light liquid contributes particularly when the interspace 36 of the separating wall 30 in the collector 20 along the threads of this separating wall 30 exhibits a variable, preferably periodically variable horizontal-radial light. Thereby, the fluid moving in the interspace 36 from the inlet pipe 14 to the outlet pipe 44 is subjected to pulsating changes in its pressure and velocity ratios, which support the desired separation of the light liquid from the heavy liquid.

Claims (12)

Separator for separating biphasic liquid mixtures comprising a smaller proportion of light liquid and a larger proportion of heavy liquid, optionally containing sludge, such as oil-contaminated and possibly sludge containing water, with a separating tank (12) for collecting the light liquid and optionally sludge, an inlet pipe (14) for the mixture to be separated, and an outlet pipe (16) for heavy liquid, largely cleaned of light liquid and optionally sludge, the separation tank (12) being designed to contain liquid at least to the lowest liquid level determined from the overflow (18) from the separation tank (12) to the outlet pipe (16), and within the separation tank (12) by a light liquid collector (20) having a substantially tubular vertical wall (22) ), wherein the mixture enters from the inlet pipe (14) to the interior of the collector (20) and from the lower region (26) of the collector (20) is heavy the liquid and eventually the sludge reaches the lower region (28) of the separation tank (12), and wherein a vertical separation wall (30) is arranged inside the collector (20), which is substantially shaped as a cut-out of a line surface resulting from the vertical forming ends. 32) and a horizontal helical control curve (34), and starting from the wall (22) of the collector (20), is substantially coiled in spiral threads along the axis (24) of the collector (20), and successive turns of the separating wall (30) define a helical interspace (36), while the outer outer thread of the partition wall (30) defines, together with the collector wall (22), an outer outer interspace (38), characterized in that the collector wall (22) thus as well as the separating wall (30) have an inlet pipe (14) extending over the upper edge (40, 42), which at least in the region of the outer outer space (38) lies higher than the lowest liquid level. a collector (20) and approximately tangentially to the collector (20) into the outer outer interspace (38) of the collector (20), and The outermost intermediate space (38) has at least in the region of the inlet opening (70) of the inflow pipe (14) a horizontal-radial clear width which approximately corresponds to the horizontal width of the inflow pipe (14). Separator according to claim 1, characterized in that the separating wall (30) is less wettable with light liquid on the outwardly facing side of its threads than on the inwardly facing side of its threads and the wall (22) of the collector (20). Separator according to claim 2, characterized in that the separating wall (30) is coated, coated or coated with a light-liquid-repellent material on its outwardly facing side. Separator according to claim 2, characterized in that the separating wall (30) and the collector wall (22) are coated, coated or coated with a light-wettable material on their inwardly facing sides. Separator according to claim 1, characterized in that it has a variable, preferably periodically variable, horizontal-radial clear width of the interspace (36) between the threads of the separation wall (30) along the threads of the partition wall (30). Separator according to claim 1, characterized in that the upper edge (42) of the separating wall (30) along its threads in the direction from the wall (22) of the collector (20) to its axis (24) loses its height. Separator according to claim 1, characterized in that the inlet pipe (14) and the outlet pipe (16) are substantially arranged opposite one another and that the lower edge (62) of the wall (22) of the collector (20) lies in certain areas in one - an oblique plane (64) that faces the vertical portion (68) of the downstream region (28) of the separation tank (12) lying approximately below the inlet pipe (14). Separator according to claim 1, characterized in that an exhaust pipe (44) is arranged centrally in the collector, the upper opening (46) of which is approximately at the level of the lowest liquid level and which extends to the oil-withdrawing space (48). from the lower region (50) of the oil-pumping space (48) the heavy-liquid discharge pipe (52) leads to and from the heavy liquid discharge pipe (52). near the outlet orifice (54) of the drain pipe (16) and from the upper region (56) of the oil removal chamber (48), the light liquid overflow (58) leads to the oil tank (60). Separator according to claim 8, characterized in that the take-off tube (44) is made flexible or extendable and is arranged on a floating body adapted to float on liquid. Separator according to claim 8, characterized in that the oil-pumping space (48) is arranged inside the separating tank (12) and the collector (20) inside the oil-pumping space (48). Separator according to claim 8, characterized in that the oil removal space (48) is arranged in the separation tank (12) and forms an immersion wall which extends up to the lowest level upstream of the outlet opening (54) of the drain pipe (16). the liquid and downwardly immersed in the liquid to limit the inflow of liquid from the separation tank (12) to the drain pipe (16) to the amounts of liquid from the lower region (28) of the separation tank (12). Separator according to claim 11, characterized in that in the upper region of the immersion wall, a connection is provided for the return of the liquid to the collector (20) near the lowest liquid level. -1513. Separator according to claim 1, characterized in that the lower region (28) of the separation tank (12) is designed as a sludge collection space.