DE2037366A1 - Device for separating an emulsion into its two liquid components of different densities by centrifugal force - Google Patents

Description

Patent attorneys _m 2037368

hie .-, - ,, podbiclskiallee ββ

Berlin, July 20th, 1970

BATTELLE MEMORIAL INSTITUTE GENEVA / SWITZERLAND

Device for separating an emulsion in

their two liquid components different

Centrifugal force density

As is well known, an emulsion can be formed when two are immiscible Liquids are present together, with the liquid of higher surface tension in the form of droplets in that lower surface tension is distributed. Undesired emulsion formation inevitably results from various technical processes and occurs also often when handling and especially when transporting liquids. The separation of emulsions into their constituent parts is therefore of great interest in various technical fields. So is it necessary, for example, for the treatment of industrial wastewater a as well as the wastewater when washing the containers of tankers, to achieve such separation in an effective and economical manner.

The known static separation devices generally claim a lot of space because they require decanting vessels, the dimensions of which are mostly inadmissible for the treatment of liquids on an industrial scale are big. Furthermore, their effectiveness often does not meet the current requirements of the water pollution laws.

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The known dynamic separators are more effective, however relatively complicated and, moreover, too expensive for various applications, there is therefore a need for a separating device simple, indestructible and little space-consuming construction, the allows an effective separation of liquid / liquid with little energy consumption and also significantly lower manufacturing costs than the conventional separators.

For economic reasons, the currently existing separation devices for each intended application that a compromise is made between the separation efficiency and the throughput of the treated mixture. For example, for the most complete possible separation of difficult-to-separate liquid mixtures, a Selection of facilities (e.g. supercentrifuges) currently available that high acquisition costs in relation to the throughput of the treated Have mixture. For the treatment of easily separable liquid mixtures of low value, however, there is currently a selection of facilities available, which are relatively inexpensive but less so are effective and also take up a lot of space.

The invention is based on the object of largely eliminating the above-mentioned specialist parts and a separating device of simple, space-saving and inexpensive design to create an effective Separation of emulsions allowed. '

The invention now relates to a device for separating a Emulsion into its two liquid components of different densities by centrifugal force. This device is characterized by a rotatable drum with an inlet chamber for the emulsion to be separated arranged at one end thereof and one at the other end of the Drum-arranged outlet chamber for the separated components

ORIGINAL INSPECTED

2037386

the emulsion »and an intermediate separation zone, which consists of a There is a multitude of separating channels which are arranged around an axial hub in Run lengthways and the inlet chamber sit the outlet chamber associate. The Einlaöskammer is bit one with the surrounding one Axial emulsion inlet communicating with the atmosphere, While the outlet chamber is provided on the one hand with at least one outlet which is in communication with the surrounding atmosphere, the is provided for discharging the component of lower density, in a distance from the drum turning axis that is between the radius of the Bnulirionseinlaß and the radius of the hub lies »The outlet chamber is on the other hand with at least one with the surrounding atmosphere in connection and for the removal of the component higher Provided tight serving outlet channel, which extends from a peripheral zone of the outlet chamber in the direction of the drum rotation axis to to a radial distance that is the same or slightly larger than the radial distance of the outlet for the lower density component *. , *. ■; ■ '** · ss. ■

Two exemplary embodiments of the subject matter of the invention will be described next

bend described with reference to the drawing.

1 shows a schematic axial section through a separating device according to the first exemplary embodiment;

FIG. 2 shows an axial section through a separating device the second exemplary embodiment; and

FIG. 3 is a partial sectional view along line III-III of FIG.

The separating device shown schematically in FIG. 1 comprises a rotatable drum 1 with a plurality of Trennroferen 2, the parallel

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to the drum axis of rotation 5 and surround a hub in the form of a hollow cylinder closed at both ends in two rows of circles. This has 3 * the separating tubes 2 and a cylindrical drum housing U are firmly connected to each other, so that the separating tubes 2 rotate together about the drum axis of rotation 5, the drum being driven for this purpose by a drive device (not shown) at a certain rotational speed .

The drum 1 also has two frustoconical end walls 6, 7 which are firmly connected to the foot 1 at one end of the drum and are lengthened at their outer or smaller end by an inlet pipe 8 and an outlet pipe 9, respectively. The inlet pipe 8 has a smaller diameter than the outlet pipe 9 and these pipes are each rotatably mounted in a fixed bearing 10 and 11, respectively. At its free end, the inlet pipe 8 is closed with the exception of an axial axial opening leading to the atmosphere, a feed pipe 12 passing through this opening for supplying an emulsion to be separated from a suitable source, for example from a storage container. Supplied through the inlet pipe 12 Emlusion spreads due to the W centrifugal effect on the Handung of the tube 8 from moving forward in this tube and then encounters a frusto-conical baffle Ik ₁ opposite to the wall 6 and with it an annular passage 15, forms which opens into the inlet chamber 13. This chamber 13 has a transversely arranged guide wall 16 which is firmly connected to the housing k and has a circular axial opening with a larger diameter than the inlet pipe 8. The baffle 16 is arranged in front of the hub 3 and the tubes 2 and forms an annular passage 18 for feeding the emulsion to the inlet end of these tubes 2. The baffles lU, l6 serve to deflect the emulsion so that solid impurities therein are before the inlet be deposited into the tubes 2 by centrifugal force.

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The separating tube 2 open into an outlet chamber 19 at the other end of the drum, in which a frustoconical wall 20 is arranged opposite the end wall 7 and is firmly connected to it by fastening means (not shown) in order to delimit an annular outlet channel 27. This channel 27 extends from the circumferential zone of the outlet chamber 13 in the direction of the axis of rotation 5. A pipe 21 fastened to this wall 20 extends coaxially within the outlet pipe and with it delimits an annular outflow channel 22 of the outlet channel. 27 with the Itogebung of the drum 1 connects. The free ends of the tubes 21 and 9 are provided with outwardly directed collars 23 and 2k , via which the separated liquid constituents of the emulsion are conducted into fixed, annular collectors 25 and 26, respectively.

The disconnect device described above works in the following way:

The inlet chamber 13 and the outlet duct 19 are above the pipes or 9 »21 constantly in contact with the environment. As a result of centrifugal force see spreads the emulsion supplied via the inlet pipe 12 over the wall of the rotating inlet pipe 8, moves in this before, and will afterwards. through the passage 15 to the outside driven. Then the emulsion between the guide walls lU, l6 returned in the direction of the axis 5 and arrives at the opening 17 » at which it overflows in order to then be driven outwards again through the annular space 18. The emulsion gets on this Way to the inlet of the tubes 2 and then flows through them in the direction of the outlet chamber 19

The separation takes place in the pipes 2 in the following way:

It is believed that the emulsion consists of two components, of which a component A of lower density in the form of droplets in the

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other component B of higher density is distributed. These two components are hereinafter referred to as the light and heavy components, respectively. As a result of the rotation of the drill 2 about the axis 5, the The emulsion flowing through these tubes is exposed to the effect of centrifugal force. Due to the difference in density between the two components, the light component A is pushed in the direction of the Axis of rotation 5 granted, whereby a progressive separation of the two components along the tubes 2 takes place. The heavy component B takes so the side of each tube 2 facing away from the axis of rotation 5 while the Droplets of the light component A on the axis 5 facing Side of the wall of the tubes 2 agglomerate or accumulate to form drops of increasing size.

When the two components arrive in the outlet chamber 19, will The heavy component B is driven radially outwards by centrifugal force and then penetrates the between the walls 20 and 7 formed, annular outlet channel 27. The heavy component B then reaches the drainage channel 22 at its outlet via the Collar 2fc overflows and is finally diverted through collector 26 * The enlarged drops of light component A, on the other hand, are given a thrust in the direction of axis 5 and they collect at the inlet of the pipe 21. The light component A thus accumulated then pours into the tube 21 and goes to the collar 23 »of directs them to collector 25 »

If, in contrast to the case assumed above, it is an emulsion, its heavy component B is the lighter component A is distributed, the separation by centrifugal force is equal Way in the tubes 2 »although in this case the drops of the Component B is on the opposite side »i.e. aa 4er the Ax 5 would separate away from the side. ■■ * "

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It should be noted that the fluid movement described above obtained by centrifugal force thanks to the difference in "level", in relation to the axis 5 »of the liquid which is located on the one hand in the inlet core 13 and on the other hand in the outlet chamber 19. The inlet end of the tube 21 forms an outlet through which the light component A can pour out, being the one shown in FIG Level in the chamber 19 forms. Furthermore, the “annular outlet channel 27, I, which extends up to the level of the inner tube 21 that? this level is established and at the same time ensures that the heavy component B comes from a peripheral zone of the outlet chamber is discharged.

If necessary, the dividing tubes running in the longitudinal direction can also be used be slightly inclined in relation to the axis of rotation »so that it is between its entry end and its exit end of this axis remove the movement in these tubes, by increasing the To favor the pumping action by centrifugal force. Furthermore, the Pipe cross-section possibly not circular and in particular asymmetrical be, practice the agglomeration of those that are separated in it Favor droplets. For example, each tube can have an inner ™ have flat surfaces that are »rather concave at the point where the droplets collect. Furthermore, the separating pipes do not have to, as described above, be straight forward. For example, helically wound tubes may also be used, with the pitch is large in relation to the Vicklungs diameter, around the rough stress to be reduced in length.

9 '

Since both the flow through as well as the separation by centrifugal force achieved, the separating device can uit its axis in each other desired position can be arranged. ·

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The separating device according to the second exemplary embodiment according to FIGS. 2 and 3 comprises a rotatable drum 1 with a vertical axis 5 », the drum forming an inlet chamber 13 at the upper end. The latter is provided with an upper axial inlet opening E which is in communication with the surrounding atmosphere. At the lower end of the drum 1, this forms an outlet chamber 19 'which is also in communication with the surrounding atmosphere. In addition, a plurality of vertical separation fk tubes 2 are distributed around an axial hub 3 around and extend parallel to the axis 5 of the joint, the upper inlet chamber 13 to the common lower discharge chamber 19 ·

This general drum arrangement corresponds to that of the described ' Device according to FIG. 1, the Troramelaxe only off. Construction reasons is arranged vertically instead of horizontally. Furthermore, the movement of the liquid and the separation of substances take place precisely in the same way, since in both cases they only use centrifugal force are based.

As can be seen from Fig. 2, the drum 1 is supported by its hollow zylin-A drical hat 3, which is driven by an electric motor 28 which is driven by a. Foot part 29 is worn. Furthermore, the separating tubes 2 are arranged close to one another in order to form a tube bundle which fills the annular space between the hub 3 and the cylindrical drum housing U. In this case, the tubes 2 can be firmly connected to one another by gluing.

In this second exemplary embodiment according to FIGS. 2 and 3, there are no Guide walls such as the walls 1Ί, l6 "according to FIG. 1 provided, because in numerous Such conducting means are not required for applications of the separating device in which the emulsion does not contain any solid impurities.

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As can also be seen from FIG. 2, the feed pipe 12 is for the feed the emulsion to the inlet channel 13 is provided with a valve 30 » the one setting of the Durohsatzes depending on the type of to be separated Components. The emulsion supplied to the inlet chamber 13 is given radial thrust by centrifugal force due to the rotation of the drum 1 and forms a coaxial level of equilibrium in this chamber around the axis of rotation 5, at the same radial distance R 1, as indicated by dash-dotted lines in FIG. The grain from the inlet chamber 13 " Mende emulsion penetrates the separation tubes 2 in which the separation of their Components by centrifugal force, just like already related to Fig. 1 described takes place. Furthermore, the complete Separation of the light component A from the heavy component B in the outlet chamber 19, as well as their separate discharge therefrom Chamber basically the same as described.

In the second exemplary embodiment, however, the light component A is discharged with the aid of a group of drainage pipes 31 which are attached to the wall 20 on a coaxial circle with radius R (see FIG. 3), this radius being greater than the radius of the inlet However, the opening E is smaller than that of the hub 3. The annular ^ outlet passage 27, between the walls 20 and 7 "of from · the peripheral zone of the outlet chamber 19 in the direction of the axis 5 xurüeklei- the heavy i tet, likewise opens into a set of discharge pipes 32, which is coaxial to the wall 7 on a Circle with the same radius R2 as the tubes 31 are attached. As can be seen from FIG. 2, the tubes 31 and 32 each have a first longitudinal part followed by a second, radially outwardly bent part which opens into the annular collector 25 and 26, which is connected to the surrounding atmosphere.

The one located at the inlet of the pipes 31 connected to the atmosphere light component A pours into these tubes, taking them

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a coaxial overflow level in radial »distance ü 2 * in the outlet chamber 19 forms, as shown in phantom in Fig. 2. At the same time, the heavy component B reaching the inlet of the pipes 32 via the outlet channel 27 forms a coaxial overflow level at a radial distance R 2 ", as also indicated by dash-dotted lines, which is a few millimeters greater than the distance R 2 'of the overflow level of the light component A. The light component A emerging from the tubes 31 is finally diverted through the stationary annular collector 25 while the heavy component B exiting from the tubes 32 is diverted through the stationary, annular collector 26, this being the case in general through the base 29 on the one hand and through the outer Sajsmlei ¹ 25 on the other hand is limited.

As can be seen from the above description of the two "iiasfShrungsTbeiagäele", the separating device is of "iofocUer & am. @ Space-saving design. Nevertheless, it allows an effective separation of each emulsion into its liquid components, whereby high throughputs can be achieved very easily. These essential advantages result from the special arrangement of the large number of separating pipes and the inlet and outlet chambers in the rotating drum.

The described arrangement of separating channels, which extend between a common inlet chamber and a common outlet chamber in the longitudinal direction of the drum, this chamber being provided with the inlet or outlet means described above, allows an effective use of a very large number of separating channels. This allows high throughputs can be achieved without the need for complicated feeding. "- or erfordesliefe Abfiihrungsmittel are _s uie so far in dynamic separators generally the case was shown" A crowded arrangement of the tubes 2 as i "Figures 2 and 3 _s. allows one

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Subdivision of the ring ram between hub 3 and drum housing 1 * in a maximum number of separation channels (pipes S), so that high throughputs can be achieved with minimal space requirements. Simultaneously allows such a subdivision of the separation zone into a multiplicity of separation channels or pipes, a very small hydraulic diameter to obtain for each channel what, for the reasons explained below, is particularly important for the separation of substances by centrifugal force Benefits. ·

It is well known that the Reynolds number (Re) is generally used, the eich results from the product of the flow velocity (V) in a channel times the hydraulic diameter (d) of the same, divided by the viscosity Of) of the relevant flow medium, for definition the flow in a »channel. It was also started that an effective material separation by centrifugal force is very difficult or is prevented if the mixture to be separated is below the separation channel undergoes turbulent flow conditions. Polarity should be laminar Flow or one that corresponds to a Reynolds number (Re "v.dAf) of less than about 2000, in channels for material separation be ensured by centrifugal force. Because the Viskositfit V, everyone Emulsion ^ is certain, the flow velocity w would have to be or the channel diameter d is reduced to a laminar flow to obtain. Apparently, however, a reduction in the flow velocity in a device with a certain cross section is necessary a corresponding, undesirable limitation of the throughput and consequently the separation capacity of the device. In addition, the choice is yours a device with a larger cross-section in order to achieve a low flow rate to achieve at a certain throughput, too undesirable, because this is obviously particularly disadvantageous in a centrifugal separating device. Given the mechanical

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In particular, stress causes every increase in diameter a centrifugal separation device, a corresponding limitation of the maximum rotational speed with which it can be operated, before there is a reduction in the centrifugal separation effect achieved.

A reduction in the channel diameter now allows the guarantee a laminar flow at a higher flow velocity. In order to achieve relatively high throughputs, however, it is required to use a large number of separation channels. In contrast to known centrifugal separation devices in which the use a large number of channels is excluded, for reasons particularly due to the conventional type of individual feed the channels with mixture or the discharge of the separated components are conditional, allows the separation device according to the invention, any number of separation channels in an effective manner for the separation of substances use. This results in particular from the fact that the separating channels are fed from or into a single, common inlet chamber open a single, common outlet chamber.

The arrangement of a large number of coaxial rows of separation channels with a small diameter therefore now offers no construction problems whatsoever. In addition to the tube bundles described, a large number of separating channels can be used in various ways without difficulty be formed, for example by an annular honeycomb nest arrangement or by corrugated sheets arranged next to one another.

The arrangement of a large number of separating channels around a hub also enables the channels to be rotated at a distance from the axis of rotation, ö'-r- i-ru- multiple de. ™ K? .N & ldurehn: secer8 is. As a result, results. : .h-'h y. ': -', r. ^r ' v.-e.rtni-IiTrh- Variation in the acting on the emulsion

■ fv q g Q ß / 1 3 e I ■

BATH ORIGINAL

Centrifugal force across the cross-section of the separation channel, i.e. between the the point closest to the axis of rotation and the point furthest from it Ax distant point of the cross-section of the duct. This makes it possible substantial cross-circulation of the emulsion in each separation channel avoid, which would occur as a result of a noticeable variation in the centrifugal force and thus the laminar flow, which is necessary for a satisfactory Separation by centrifugal force is required. "

The use of a common inlet and outlet chamber, like ' described in connection with the atmosphere, i.e. under atmospheric pressure stand, it allows a very even feed in a particularly simple and effective way, thanks to the centrifugal force the emulsion to the numerous separating channels, the flow through them and to achieve the dissipation of the separated components. Namely, it is now also possible to increase the throughput in a relative manner to vary a large area without the laminar flow of the emulsion, and therefore also the separation of substances by centrifugal force, unfavorable to influence, because the level formation described above results in a self-regulating effect at different throughputs. Because i ™ Furthermore, the movement of the emulsion and the separated components is achieved by centrifugal force, the use of separate Pumping means and e.g. a feed pump are no longer required. This allows a significant simplification of the requirements for the separating device Equipment, from which a reduction in acquisition and operating costs can be achieved.

The following numerical example serves to explain the above Advantages.

ORIGINAL. fNSWrC!? D 109808/1398

- 11 »-

example

A separating device according to Fig. 2 and 3 * with a steel drum with a diameter of 56 cm and a hub diameter of bo cm er '· The installation of 830 separating pipes with an inner diameter of 1 cm,

A drum speed of 2000 rpm, depending on the distance, results in each Separating tube from the drum axis of rotation, a centrifugal acceleration, which is about 900 to 1250 times greater than the acceleration due to gravity.

The maximum throughput of the emulsion at which a complete separation, with laminar flow, can be achieved in the separation tubes of the drum, depends from case to case on the size of the droplets to be separated from the emulsion. A drum with the dimensions given above, a separation tube length of 20 cm and a speed of 2000 rpm, allows complete material separation with throughputs of up to Wj in / h. When the size of the droplets to be separated is not more than 0.03 mm. For complete separation of an emulsion which contains droplets of 0.01 mm, the maximum throughput is, however, about k m / h. -

As can be seen from the above explanations, the separating device described allows the aforementioned disadvantages of known separating devices to be eliminated. This is directly due to the special rotary drum arrangement described above for the back-up tube _9, with a large number of relatively sctanal trench cannulas extending in the longitudinal direction of the drum around a hub with a significantly larger diameter than

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the channels, extend between a common inlet chamber and a common outlet channel, and these chambers are under atmospheric pressure. Thanks to this special arrangement, it becomes namely possible to create optimal separation conditions and also a high To achieve throughput in a rotating drum of the simplest design, whereby the space requirement and the acquisition costs of the drum are relatively low.

The separation device described is suitable for a wide variety of applications Areas of application, since it is no longer necessary to make a compromise between the transmission performance and the throughput. For example, this separating device can be used for the treatment of wastewater, such as the wastewater when washing the tanks of tankers or the steelworks wastewater.

This separation device can also be used in various industrial sectors e.g. in mineral chemistry or in the raw material industry (mineral).

Another important field of application of the subject matter of the invention is the food industry. The separating device described is particularly suitable, for example, for the treatment of milk, of Vegetable oil or from fish oil.

1 0 9 8 0 8 ■ '1 3 9 8

Claims (2)

Claims 1. Device for separating an emulsion into its two liquid components different densities characterized by centrifugal force by a rotatable drum (1) with one at one end thereof Inlet chamber (13) for the emulsion to be separated, an outlet chamber (19) used at the other end of the drum (1) for the separated constituents of the emulsion, and an intermediate separation zone, which consists of a plurality of separation channels (2) which run around an axial hub (3) in the longitudinal direction and the input ' Let chamber (13) with the outlet chamber (19) connect, wherein the inlet chamber (13) with a with the surrounding atmosphere in connection standing axial emulsion inlet (8) is provided, and wherein the Auslas skaminer (19) on the one hand with at least one, with the surrounding atmosphere communicating outlet (21; 31) is provided, which is provided for discharging the component of lower density, in one Distance from the drum rotary axis (5) »that between the radius of the emulsion inlet (8) and the radius of the hub (3), and wherein the outlet chamber (19) on the other hand with at least one with the surrounding Atmosphere communicating and for discharging the component of higher density serving outlet channel (27) is provided, which is from a peripheral zone of the outlet chamber (19) in the direction of the drum rotary axis (5) extends up to a radial distance which is equal to or slightly larger than the radial distance of the outlet (21; 31) for the lower density component. 2. Apparatus according to claim 1, characterized by the outlet end of the Tror-rr.e ;! (l) abschiiessende end wall (7) and by a distance from this arranged septum (20) _s and these two walls (7, 20) 109808/1398 delimit a radially extending annular space "which the outlet channel (27) "forms, and this on the one hand with the Peripheral zone of the outlet chamber (19) and on the other hand over at least a second outlet (22; 32) for discharging the heavier component communicates with the surrounding atmosphere, and wherein this second outlet (22; 32) in the same or a little larger radial Distance than the first outlet (9; 31) for discharging the component lower density, at the end closer to the axis of rotation (5) | of the outlet channel (27) is connected. 109808/1398