JPS6116483B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention provides a method for separating gas and liquid.
This invention relates to a liquid separation device. a central upflow tube that is open at the top and communicates through an overflow edge with a separator hood that is mounted over and around the top of the upflow tube; Gas-liquid separators are known in which the separator hood has a gas outlet above the overflow edge and a liquid outlet below the overflow edge but outside the upflow tube. However, the present invention relates to an improvement thereof.

The simplest of the above types of devices is one having a cylindrical upflow tube and an overflow edge formed from the upper edge of the upflow tube. A device of this type is disclosed, for example, in Dutch patent application No. 7512807.

The degree of separation when performing gas-liquid separation in the above type of equipment depends on the residence conditions (time) of the "each phase to be separated" in the separator hood and the motion (flow) conditions of these phases through the overflow edge. It has recently been discovered that this depends on "a comprehensive condition consisting of a combination of two conditions". In some applications, for example when using slurry-type or slurry reactors to synthesize hydrocarbons from synthesis gas, a catalyst is present in the recycled liquid product or circulating auxiliary liquid. and separating the liquid and catalyst from the unconverted gaseous matter and gaseous by-products at the top of the upflow reactor, and the thus separated liquid and catalyst are cooled outside the reactor. If the simplest type of known separator mentioned above is used for this operation, the annular overflow edge alone will not produce the desired amount. It was found that a sufficient separation effect could not be obtained. Therefore, in order to perform this field satisfactorily, the separation must be carried out in the "separate-hood space" that exists outside the upflow tube, but in this case, the separation must be carried out in the "separate-hood space" which exists outside the upflow tube, but in this case there is a very large area below the overflow edge. It must be possible to maintain a liquid level with a large surface area. For this purpose, the outer diameter of the separator hood must be many times larger than the outer diameter of the upflow tube, but it has been found that this type of reactor is not practical.

The object of the present invention is to solve the above problem, and the present invention solves the above problem by increasing the length of the overflow edge instead of increasing the liquid surface area of the separator hood. It is something.

The present invention therefore forms an overflow edge by a series of partitions, which partitions continue across the space directly above the upflow pipe to the next space, and which partitions extend over the upflow pipe. The space in the separator hood directly above the flow tube and the space adjacent thereto is divided into two types of compartments, each compartment being open at the top and each compartment occupying the space above the upflow tube. and the space next to it, one type of compartment of which constitutes a riser, the bottom of which does not lie in the space above said upflow pipe, but extends into the space next to it. The other type of compartment, on the other hand, constitutes a downcomer, the bottom of which lies in the space above the upstream tube, but in the space next to it. The present invention relates to a gas-liquid separation device characterized in that the riser and the downcomer have one partition common to them which is always located next to each other. The top edge of all of the partitions described above essentially serves as an overflow edge. The liquid rises in the upflow tube and from there enters the riser compartment (also referred to as the "riser"). This riser compartment is located "between the two partitions that make up the riser." The liquid then fills not only a part of the riser (i.e. the area present in the space above the upflow tube; there is no bottom in this part), but also the "remaining area" of the riser ( That is, it also exists not in the space above the upflow pipe, but in the space next to it (where the bottom is located).

Liquid is allowed to flow over the edge of one of the two riser partitions into the adjacent downcomer compartment. Therefore, the liquid can flow in the following two flow modes.

(a) liquid flows over a partition immediately above said updraft tube, and then from the area above said updraft tube in the riser to the area above said updraft tube in the downcomer; (where the bottom is), the liquid flows along the bottom of this downcomer and the area in the downcomer that is not in the space above the upflow tube but in the space next to it. ”
(there is no bottom here), after which the liquid
The liquid enters the "area next to the upflow tube" (ie the area below the partition) in this separator hood and then leaves the separator hood via a liquid outlet.

(b) liquid flows over a partition adjacent to the space above the updraft tube and from "an area adjacent to the space above the updraft tube" in the riser;
The liquid flows into the area of the downcomer that is adjacent to the space above the upflow tube (there is no bottom in this area of the downcomer), so that liquid flows into the separator hood. It flows directly into the "space next to the upflow tube" (ie the space below the partition) and then the liquid leaves this separator hood via the liquid outlet.

In the apparatus of the present invention, there is generally some foaming in the liquid at the top of the upcomer and in the riser, and the specific gravity of the liquid is lower than the specific gravity of the liquid in the downcomer. The liquid level in the riser reaches almost the upper edge of the partition. On the other hand, in many cases, the liquid level in the "area adjacent to the space above the upflow tube" in the downcomer is lower than the position of the partition (i.e., the upflow lower than the top edge of the tube). However, as can be readily appreciated, the location of these liquid levels then depends on the surface area of the passages in the riser and downcomer, and also on the exit velocity through the liquid outlet; It also depends on liquid level control means, if any.

The partitions present in the device of the invention are formed so as to extend across the space immediately above the upflow pipe and the space adjacent thereto. The bottom of the riser is in a space adjacent to the space above the upflow pipe;
The bottom of the downcomer resides in the space above the upflow tube. These bottoms can therefore fit both the partition and the upflow tube. This structure prevents liquid from flowing directly from the upstream tube to the downcomer, and from the riser to the space adjacent to the upstream tube. That is, the liquid always flows over the edge of the partition, and this edge actually plays the role of an "overflow edge."

By increasing the number of partitions and increasing the number of risers and downcomers, the overall length of the overflow edge can be increased. In this configuration, the length of the overflow edge can be increased many times compared to when the top of the upflow tube itself is used as a (circular) overflow edge, but this is easily achieved. will be understood. However, since it seems necessary for the above-mentioned compartment to have a width above a certain minimum value in order to effect gas-liquid separation, this condition imposes a certain limit on the number of partitions. sell.

In a preferred embodiment of the invention, all the partitions have horizontal top edges, and the top edges are all arranged in one plane. This embodiment is generally preferred. This is because it is the simplest to manufacture and all of these overflow edge members have equal effectiveness. However, it is of course possible to manufacture a separation device according to embodiments other than those described above while retaining at least some of the effects of the present invention.

In the present invention, the partitions are preferably arranged radially (in the radial direction). This arrangement is particularly preferred in the following cases. That is, the upflow tube and the separator hood have a circular cross section, which is particularly preferred when high pressure is applied within the upflow tube. If the partitions are arranged radially, all risers and/or downcomers are "equivalent" and each of these risers and downcomers can be equally spaced around the periphery of the upflow pipe. , Therefore, the effect is obtained that the respective loads on these risers and downcomers are all the same.

A disadvantage of radially arranging the partitions is that the width of each compartment varies from location to location. It is also possible, for example, for the partitions to be arranged parallel to each other, but in this case special attention must be paid to the construction of the two sides of the separator hood, and in this case the partitions are also free from the upward flow. It is not possible to cross both the space above the tube and the space next to it.

When the partitions are arranged radially, it may be preferred that these partitions do not extend above the upflow tube at the center line of extension of the upflow tube. When the partition is extended as described above, the lower part of the compartment becomes narrow, ie wedge-shaped. In this case, there is not enough space for the partitions, and the top of each compartment near this central point serves only a small amount for gas-liquid separation. Furthermore, the two partitions on either side of a compartment are brought into close proximity at the above point, at which point the width of the compartment becomes extremely narrow.

When the partitions are extended to the center line of the upflow pipe as described above, each of the partitions is connected to two adjacent partitions on the upflow pipe according to the invention. , or through a lateral partition. This provides better structural rigidity for the compartment, and in the case of downcomers, the above-mentioned transverse partition serves as an overflow edge for liquid rising up the center of the upflow tube. It can play a role.
The lower edge of said transverse partition of the downcomer can be attached to the bottom of the downcomer. On the other hand, the height of the upper edge of these transverse partitions is
The height may be the same as the height of the upper edge of the radial partition. Unless there are structural strength reasons, the riser does not require a cross-section, and in this case the cross-section does not serve as an overflow edge; It does not contribute to the total length extension of

Particularly when the phases to be separated also contain solids, e.g. in hydrocarbon slurry reactors, when the phases to be separated from the gas phase contain the hydrocarbon itself with solid catalyst particles or an auxiliary liquid. or if the presence of dead corners in the separator hood is not permissible [this "dead corner" is defined as the residence time of the phase (e.g. liquid phase) for a long time, e.g. According to the invention, each base is preferably provided with a descending slope, so that this slope is arranged in the wall of the upflow tube on the underside of the compartment to which it belongs. It is preferable to attach it so that it descends in the direction of the exposed wall. In the case of the bottom of the riser located in the space next to the space above the upflow pipe, it is advisable to provide an inward slope. The bottom of the downcomer, which is located in the space above the upflow tube, may be sloped outwards. If desired, to save material, the lower edge of the partition can be shaped to suit the bottom of this particular structure.

In particular, when a relatively large amount of liquid must be separated from gas, the angle formed by the two partitions forming the riser should be smaller than 15 degrees, and the angle formed by the two partitions forming the downcomer should be is preferably greater than 15 degrees [angle measured in radial position (see Figure 2)].

On the other hand, in another embodiment of the invention, which is very useful, for example, when relatively small amounts of liquid have to be separated from the gaseous phase, the angle between the two partitions forming the partition is 15 degrees. The angle between the two partitions that form the downcomer is
It is preferable to make the angle smaller than 15 degrees.

As can be readily appreciated, if the partitions are arranged radially and the risers and downcomers have the same angle, the surface area of the passages in the risers and downcomers will be the same as the upflow tubes and The value is determined by the diameter of the separator hood (however, the partition in this case is
across the space above and adjacent to the updraft pipe). In order to minimize the diameter of the separator hood, the angle between the two partitions forming the downcomer compartment is preferably greater than the angle between the two partitions forming the riser compartment. On the other hand, when the total number of compartments decreases, the total length of the overflow edge also decreases. Furthermore, the value of the ratio (area ratio, etc.) between the riser passage and the downcomer passage should not be far from the calculated value calculated from the quantitative ratio of the gas and liquid to be separated. It won't happen. This is because if the values are far apart, there will be wasted space. When a total of 12 risers and a total of 12 downcomers were formed,
It has been found that the balance against various contradictory conditions is improved. In this case, it is preferable that the total angle of the riser and the adjacent downcomer is 30 degrees.

In one embodiment of the invention, the partition is configured to extend to the wall of the separator hood. This method simplifies the structure of the device. That is,
In this case the separator hood itself provides the necessary rear wall for the riser compartment, while the partition and the bottom can be attached to the separator hood. However, it is also possible to create devices with more complex structures than those described above. Also,
In the embodiment described above, in each riser, the bottom strip adjacent to the separator hood can be omitted, while at the beginning of the bottom, the partitions of each riser can be connected via transverse partitions. In this way an additional downcomer is formed, which lies entirely next to the space above the upflow tube,
These transverse partitions form overflow edges.

In a device according to another embodiment of the invention, which can be used with particular advantage in slurry reactors, the bottom is formed at an angle with respect to the horizontal plane. The apparatus according to this specific example is particularly effective when the liquid to be separated contains solid particles such as a catalyst.

The invention also includes a reaction vessel configured as an upflow tube, with a separator hood above the reaction vessel, an opening of the reaction vessel communicating with the separator hood via an overflow edge, and a separator hood above the reaction vessel. The gas outlet of the hood is above the overflow edge, the liquid outlet of this separator hood is below the overflow edge but outside the reaction vessel, and the liquid outlet is located outside the reaction vessel. It also relates to a slurry reactor, characterized in that it communicates via a cooler with the bottom of the reaction vessel, at which a gas inlet is also fitted. A separator hood with an overflow edge in this case can be constructed according to any of the various embodiments of the invention described above. This slurry reactor is a reactor suitable for synthesizing "products that are liquid under synthesis conditions" by performing a catalytic conversion reactor to gas in the presence of recycled products containing catalysts. . The recycle liquid containing the catalyst passes upward through the reactor together with the gas. In the separator hood, the unconverted gases together with the gaseous reactants are separated from the liquid (including the catalyst), the liquid is cooled outside the reactor and then recycled to the bottom of the reactor. A portion of the liquid is discharged as product.

Another use of this slurry reactor is to synthesize gaseous products from feed gas under the action of a catalyst suspended in a recirculated auxiliary liquid. These gases can then be separated from the auxiliary liquid. This slurry reactor can also be used in other ways than the above two ways of using it, for example:
without external cooling of the liquid separated from the gas or recirculation of the separated liquid;
Alternatively, the catalyst may remain in the reactor during the gas-liquid separation operation.

Preferably, the drainage equipment in the separator hood has at least four drain pipes equally spaced around the periphery of the separator hood, each of which drains the reactor via a separate heat exchanger. Connect it to the bottom of the This embodiment is particularly suitable for synthesizing one or more hydrocarbons from a gas containing hydrogen and carbon monoxide. A considerable amount of heat is generated in the reactor during the synthesis of fissures and tropshus, but this heat can be effectively removed by the above method.

Next, some specific examples of the present invention will be described in detail with reference to the accompanying drawings.

First, the first one made according to one embodiment of the present invention
The principle and structure of the illustrated slurry reactor will be explained.

The slurry reactor (vertical reactor) 1 is constructed in the form of an upflow tube, i.e. through which a liquid phase containing catalyst particles and a gas phase pass.
It's starting to rise. The upper edge 2 of the reaction vessel 1 is cut in a straight line, so that the upper edge 2 is circular and rests on a horizontal plane.

A separator hood 3 is attached to the top of the upper part of the reaction tank 1 and around it. The diameter of the separator hood 3 is larger than the diameter of the reaction vessel 1.
The top of the hood 3 is closed by a cover 4 with a central gas inlet 5. The lower part of the hood 3 lies next to the upper edge 2 of the reaction vessel 1, ie the lower part of the hood 3 constitutes a bottom 6, which slopes downward inward. In the bottom part 6 there are four drain pipes 7, two of which are shown in FIG.

In the space immediately above and adjacent to the upflow pipe 1, the hood 3 has a series of partitions,
This will be explained in detail later with reference to FIGS. 2 and 3. This partition forms a series of overflow edges, i.e., this overflow edge lies in the horizontal plane 8 passing through the upper edge of the upright partition 9, so that the upper edge of the upright partition 9 itself also has an overflow edge. It is. Liquid and gas are separated by several pairs of upright partitions 9.
between them and rises towards plane 8, where the liquid passes over the overflow edge and flows down between several other pairs of upright partitions into the space immediately above reactor 1. reaches the annular space 10 next to (which lies below the plane 8). The liquid then flows from the annular space 10 via the discharge pipe to the heat exchanger 11 and from there via the pipe 13 into the bottom of the reactor 1.

The gas phase separated from the liquid while it flows as an overflow edge stream in the hood 3 collects in the space 14 above the plane 8 and is then discharged from there via the outlet 5. In the bottom 12 of the reactor,
Fresh gas is supplied through the inlet pipe 15.

By using this slurry reactor, hydrocarbons can be synthesized from synthesis gas containing, for example, H ₂ and CO. The synthesis operation in this case can be carried out as follows, for example. The synthesis gas is fed through a line 15, and the liquid product containing the catalyst required for the synthesis in suspension is passed together with the synthesis gas through the reactor 1 and raised, and the liquid product is raised in the hood 3. unconverted gas and gaseous reaction products (including the catalyst) are separated, these gases being discharged via pipe 5, and the liquid products and catalyst being transferred to the reaction via pipe 7, heat exchanger 11 and pipe 13. It is recycled to the bottom 12 of vessel 1 (liquid product and catalyst being cooled in heat exchanger 11). However, excess products and the catalyst to be regenerated are discharged from the hood 3 through the discharge nozzle 16.

In the case of hydrocarbon synthesis, external cooling is often advantageous, since the synthesis reaction is highly exothermic.

The structure of the series of partitions in the hood 3 of the apparatus shown in FIG. 1 will be explained in more detail with reference to FIGS. 2 and 3.

As can be seen from FIG. 2 (top view), the upright partitions 9 are arranged radially (ie radially) in the hood in a particular arrangement. These partitions 9 extend in plane 8 from the wall of hood 3 towards cylindrical opening 17 . Cylindrical opening 17
exists in the center of the hood 3. There are two types of angles between each of these partitions 9 and the adjacent partition 9: "small" and "large", and the "small" angle is
10 degrees, and the "large" angle is 20 degrees.

The upper edge 18 of the partition 9 in the plane 8 constitutes an overflow edge (see FIG. 3).

There is a bottom part 19 between two partition parts 9 adjacent to each other with an included angle of 10 degrees, and the bottom part 19 is
It lies between the wall of the hood 3 and the upper edge 2 of the upflow tube 1, the bottom 19 of which slopes downwardly towards the inside. This is because it abuts the wall of the hood 3 at the level of the plane 8 (i.e. at the level of the upper edge of the upright partition 9), while it abuts the upper edge 2 of the upflow tube 1. This is because they are in contact with the plane 8 slightly below. The bottom 19 ends at the edge 2, in other words there is no bottom 19 in the space above the tube 1 even between the two vertical partitions.

Regarding the bottom 20 between two adjacent vertical partitions 9 with an included angle of 20 degrees,
The bottom 20 is present in the space above the tube 1 and extends from the upper edge 2 of the tube 1 towards the cylindrical opening 17. The starting point of this bottom part is at the same height as the upper edge 2, while the ending part is in the cylindrical opening 17, but its height is slightly lower than the height of the plane 8; There is Edge 21. From the edge 21 to the transverse partition 22
extends at right angles to the plane 8, i.e.
up to the height of the upper edge 18 of the partition 9,
It extends upward. The bottom part 20 is present in the space above the upflow pipe 1, in other words the bottom part 20
does not extend into the space next to it. bottom 19
and 20 and the partition 22 are welded at appropriate locations between the partitions 9.

From the above structure, it will be understood that there are two types of compartments between the partitions 9: a riser compartment and a downcomer compartment.

That is, the riser compartment exists between two adjacent partitions 9 at an included angle of 10 degrees,
The bottom of this riser compartment is open in the space above the upflow tube 1 (i.e. there is no bottom), while in the space next to it it is closed (i.e. there is a bottom 19).

The downcomer compartment exists between two adjacent partitions 9 at an included angle of 20 degrees,
The bottom of this downcomer compartment is closed in the space above the upflow tube 1 (i.e. there is a bottom 20), while in the space next to it it is open (i.e. there is no bottom). ). Furthermore, in the space above the upflow pipe 1, the downcomer compartment (viewed in the radial direction) is closed on its inside (transverse partition 22).

The operation of the series of partitions and bottoms specifically described herein and in the accompanying drawings will now be described in detail.

Figure 3 shows a perspective view of three compartments; the first one is the riser compartment, the next one is the downcomer compartment, and the one at the back is the riser compartment.

The liquid and gas phases rise from the reactor 1 between the two partition walls 9 of the riser compartment, pass through the space inside the circle of the transverse partition 22 and reach the overflow edges 18 and 23. As these fluid phases flow over the edges 18 and 23, the phases are separated from each other, with the gas phase proceeding upward and being discharged out of the system, while the liquid phase flows down between the partitions 9 and 22. flowing down through the comer,
It reaches the space 10 next to the reactor 1 and flows down from there.

The riser compartment has a special shape that widens towards the top, making it easier to dispose of large foam particles formed in the hood 3. On the other hand, since the bottom portions 19 and 20 are sloped, there cannot be any dead corners (corners where catalyst particles remain).

FIG. 4 is an explanatory diagram of a separation device having a structure that is greatly simplified from the structure shown in FIG.
Two riser compartments are shown in FIG. 4, surrounded by radial partitions 24 and 25 and radial partitions 26 and 27, respectively. Between partitions 25 and 6 there is a downcomer compartment.

At the top of the wall 28 of the reactor 1 there is a horizontal circular edge 29, which includes the bottom 30 of the riser;
Bottom part 31 of the downcomer and bottom part 3 of the riser
2 are connected by welding. These bases are all in one plane, so the plane is edge 2
9, and the lower edges of the partitions 24-27.

Each of the bottom portions 31 is tapered, and the bottom portions touch each other at a central point. Bottoms 30 and 32 extend from edge 29 towards wall 33 of the separator hood.

The top edges of the partitions 24-27 lie in one horizontal plane and constitute overflow edges. The space above this plane, but inside wall 33, is a gas accumulation space, and the space below this plane, but between walls 28 and 33, is a liquid discharge space.

As is clear from the foregoing description, the following slurry reactor and synthesis method are also provided in accordance with the present invention.

(1) having a reaction vessel configured as an upflow tube with a separator hood above it, the opening of the reaction vessel communicating with the separator hood via an overflow edge; a gas outlet above said overflow edge, and a liquid outlet below said overflow edge but outside said reaction vessel, said liquid outlet being connected to said liquid outlet via a cooler disposed outside said reaction vessel; In a slurry reactor, the separator hood having an overflow edge is connected to the bottom of the reactor and a gas inlet is also installed at the bottom, according to any one of claims 1 to 10. A slurry reactor characterized by having the structure described above.

(2) In the slurry reactor according to paragraph 1 above, the liquid discharge equipment has at least four discharge pipes arranged at equal intervals around the periphery of the separator hood, and A slurry reactor, characterized in that each of the discharge pipes of is connected to the bottom of the reactor via a separate heat exchanger.

(3) In a method for synthesizing a gaseous or liquid product by performing a catalytic conversion reaction of gas in the presence of a catalyst in a liquid product or an auxiliary liquid, the slurry reactor according to item 1 or 2 above. A method characterized by using.

(4) A method for synthesizing "a product that is liquid under synthesis conditions" by performing a catalytic conversion reaction of gas in the presence of a recycled product containing a catalyst, the slurry reaction according to item 1 or 2 above. A method characterized by using a container.

(5) The synthesis method according to item 4 above, characterized in that one or more hydrocarbons are synthesized from a gas containing hydrogen and carbon monoxide.

[Brief explanation of the drawing]

FIG. 1 is a schematic longitudinal cross-sectional view of a separator hooded slurry reactor constructed in accordance with one embodiment of the present invention. FIG. 2 is an enlarged sectional view of a portion of the reactor shown in FIG. 1 taken along line -. 3 is a schematic perspective view of a portion of the inside of the separator hood shown in FIGS. 1 and 2; FIG. FIG. 4 shows a portion of the inside of a separator hood made in accordance with another embodiment of the invention.
FIG. 4 is a schematic perspective view of the "portion" shown in FIG. 3; DESCRIPTION OF SYMBOLS 1...Slurry reactor (reaction tank) in the form of an upflow tube, 2...Top edge, 3...Separator hood, 4...Gover, 5...Gas outlet, 6...Bottom of separator hood, 7... ...Drain pipe, 8...
Horizontal surface, 9... Upright partition, 10... Annular space,
11... Heat exchanger, 12... Bottom of reactor, 15
...Gas introduction pipe, 16...Discharge nozzle, 17...
... cylindrical openings, 18 and 23 ... overflow edges, 19 and 20 ... bottom of the compartment, 21 ... edges, 22 ... transverse partitions, 24, 24, 26 and 27 ... radial (radial) partitions Parts, 28 and 33...Wall part, 2
9... Horizontal circular edge, 30 and 32... Bottom of riser, 31... Bottom of downcomer.

Claims (1)

Claims: 1 having a central upflow tube, the opening at the top of the central upflow tube communicating through an overflow edge with a separator hood, the separator hood being connected to the top of the upflow tube and its surroundings; the separator hood has a gas outlet above the overflow edge and a liquid outlet below the overflow edge but outside the upflow tube. In the liquid separator, the overflow edge is formed by a series of partitions that extend across the space directly above the upflow pipe and continue into the space adjacent thereto. These partitions divide the space in the separator hood directly above the upflow pipe and the space adjacent thereto into two types of compartments, and the tops of these compartments are open. , each compartment extending into the space above and adjacent to the upflow tube;
one of the compartments constitutes a riser, the bottom of which does not lie in the space above the upflow pipe, but in the space next to it;
Another type of compartment constitutes a downcomer, the bottom of which is present in the space above the upflow pipe but not in the space next to it, and the riser and downcomer are always located next to each other. A gas-liquid separator characterized in that it has one partition section common to the two. 2. In the device according to claim 1,
all of the partitions have horizontal upper edges;
and a device characterized in that all of these upper edges lie in one plane. 3. The device according to claim 1 or 2, wherein the plurality of partitions are arranged radially (radially). 4. In the device according to claim 3,
Above the upflow tube, the partition does not extend as far as the elongated centerline of the upflow tube. 5. In the device according to claim 4,
An apparatus characterized in that an end portion of each of the partition portions is connected to each unend portion of two adjacent partition portions on the upflow pipe via a transverse partition portion. . 6. The device according to any one of claims 1 to 5, in the direction of "a portion of the wall of the upflow tube" located below the compartment to which each bottom belongs. A device characterized in that each bottom slopes downward. 7. In the device according to claim 3,
An apparatus characterized in that the angle formed by the two partitions forming the riser is less than 15 degrees, and the angle formed by the two partitions forming the downcomer is larger than 15 degrees. 8. In the device according to claim 3,
An apparatus characterized in that the angle formed by the two partitions forming the riser is greater than 15 degrees, and the angle formed by the two partitions forming the downcomer is smaller than 15 degrees. 9. The device according to any one of claims 1 to 8, characterized in that the partition extends to the wall of the separator hood. 10. A device according to claim 6, characterized in that said bottom portion is arranged at an angle with respect to said horizontal plane.