FR3043339A1 - FILTRATION AND DISTRIBUTION DEVICE FOR CATALYTIC REACTOR - Google Patents

Abstract

The present invention relates to a device for filtering and distributing (1) a gaseous phase and a liquid phase, able to be disposed upstream of a fixed catalytic bed (4) of a reactor (2) operating at downward co-current of gas and liquid, comprising: • a solid plate (6) extending in a horizontal plane on which are fixed substantially vertical chimneys (7) open at their upper and lower end, said chimneys being provided with openings over at least a fraction of their height; A plurality of removable baskets adapted to contain and retain a filter media, each removable basket being defined by an ellipsoidal vertical wall (14) or by at least three vertical side walls and a bottom (13), the vertical walls and / or the bottom being permeable to gas and liquid. Each basket is provided with at least one support means (16) of the basket cooperating with a chimney (7) of the plate to support the filter basket.

Description

The present invention relates to the field of distributor trays for supplying gas and liquid chemical reactors operating downward co-current of gas and liquid.

Such reactors are encountered in the field of refining, particularly in hydrotreatments which require high pressure hydrogen flows and working with heavy liquid charges which may contain impurities consisting of clogging solid particles.

In certain cases, in fact, the liquid charge, or even the mixture of the liquid feedstock and a hydrogen-rich gas under the conditions of temperature and pressure necessary for the hydrotreatment, contains impurities which can be deposited on the catalytic bed. itself and, over time, reduce the interstitial volume of the catalytic bed and thus lead to a gradual increase in the pressure drop. In extreme cases, particularly at the end of the cycle, a clogging of the catalytic bed is observed, which results in a very rapid rise in pressure drop, thus disturbing the flow through the reactor.

The pressure drop can become such that the operator is obliged to stop the reactor and replace some or all of the catalyst, which of course leads to a considerable reduction in the cycle times of the process.

Among these clogging fillers, there may be mentioned hydrocarbon mixtures which may contain a significant proportion of unsaturated or polyunsaturated acetylenic or diene compounds, or a combination of these various compounds, the total proportion of unsaturated compounds up to 90 % weight in the load. By way of a representative example of the feeds concerned by the present invention, mention may be made of the essence of pyrolysis, pyrolysis denoting a thermal cracking process well known to those skilled in the art. We can also mention the heavy cuts of hydrocarbons, including gas oils, gas oils under vacuum, atmospheric residues or residues under vacuum. These heavy cuts may be derived from direct distillation of crude oil or from a conversion process such as visbreaking, coking, deasphalting, catalytic cracking or hydrocracking.

Clogging of part of the catalytic bed may be due to several mechanisms.

Directly, the presence of particles in the flow of the charge can cause clogging by deposition of said particles within the catalytic bed, this deposit having the effect of reducing the void fraction.

Indirectly, the formation of a layer of products resulting from chemical reactions, typically coke, but possibly other solid products derived from the impurities present in the feed, which products are deposited on the surface of the catalyst grains, can also contribute to the reduction of the empty fraction of the bed.

The heavy hydrocarbon cuts mentioned above may also contain various impurities, in particular iron or calcium derivatives which may contribute to the clogging of the catalytic beds. Residual-type cuts also contain asphaltenes, which are chemical compounds often described as coke precursors. Moreover, the deposition of the clogging particles can be done within the bed more or less randomly, it may result in heterogeneities in the distribution of the empty fraction of this bed which will result in the creation of preferential paths.

These preferential paths are extremely detrimental hydrodynamically because they disturb more or less severely the homogeneity of the phase flow in the bed and can lead to heterogeneities in the progress of the chemical reaction, as well as thermally (difference in radial temperature, hot spot for example).

State of the art

To prevent premature clogging of the catalytic bed, various technical solutions have been developed which are based on the use of a filtration system arranged upstream of the catalytic bed (in the direction of fluid flow).

For example, mention may be made of: Document FR 2 889 973, which discloses a distribution plate which directly supports a filtering medium, thus provides both the filtration functions with respect to the downstream catalytic bed and the distribution of the gas fluids and liquid. The filtering tray according to FR 2 889 973 comprises chimneys having perforated holes (or slots) in the middle of the filtration bed, which can pose difficulties in the case of a closure of the bed near the holes. This clogging of the bed would consequently result in the clogging of the chimney with two consequences: an imbalance of the distribution of the liquid flow under the distribution tray, and a risk of damaging the chimneys during dismantling of the tray with glued and aggregated chimneys in the filter bed. • the document FR2959677 which describes a set of removable baskets containing filter particles, these baskets being deposited on the dispenser tray to facilitate the assembly / disassembly of the filter device without intervening on the distributor plate. To ensure mechanical integrity of the basket system, said removable baskets are held together by bolting or a staple system thus complicating assembly and disassembly operations. Document FR 2,996,465, which discloses a filtration and distribution assembly of a gas and liquid phase comprising a distributor plate provided with distribution funnels and an upper perforated filtration support, on which a bed of filter media is placed, which is crossed by the chimneys of the distributor tray. The filter support is mechanically held in the distributor plate by means of a bent piece placed between said support and the plate or by a screwing system. The main difficulty of implementation of this system lies in the filling of the filter media which must be done once the support is put in place in the reactor and especially during the dismantling of the system which supposes a prior emptying of the support since the inside the reactor, made even more difficult in case of agglomeration (or setting in mass) of the filter media.

An object of the invention is to provide a new filtration and distribution device for a co-current flow reactor descending a gas phase and a liquid phase which is easier to install and disassemble, thus reducing the immobilization time of the reactor and limit the risk of degradation of said device during disassembly operations. SUMMARY OF THE INVENTION For this purpose, it is proposed a device for filtering and distributing a gaseous phase and a liquid phase, capable of being disposed upstream of a fixed catalytic bed of a reactor operating at a temperature of -current descending gas and liquid, comprising: • a solid plate extending in a horizontal plane on which are fixed substantially vertical chimneys open at their upper and lower end, said chimneys being provided with openings on at least a fraction their height; A plurality of removable baskets able to contain and hold a filter medium, each removable basket being defined by an ellipsoidal vertical wall or by at least three vertical side walls and a bottom, the vertical walls and / or the bottom being permeable to gas and to the liquid and wherein each basket is provided with at least one basket support means cooperating with a stack of the tray to support the filter basket.

The assembly operations and disassembly compared to the devices of the prior art are facilitated since in the device according to the invention the removable baskets are supported directly by the chimneys; it is therefore not necessary to implement additional means for fixing the baskets to the dispenser tray, such as for example screws or staples.

In addition to their support function for removable baskets, the stacks of the distributor plate provide a guiding function during the installation of said baskets.

Another advantage of the device according to the invention lies in the fact that the loading of the baskets in filtering media can be done outside the reactor, which greatly facilitates and accelerates the operation, which is then limited to the implementation of place loaded baskets over the dispenser tray. In addition, the height of the filtration particles in each basket can be adjusted very precisely basket by basket.

According to one embodiment, the bottom of the basket is traversed by at least one chimney and the support means cooperates with the chimney which passes through the bottom.

According to another embodiment, at least one of the side walls of the basket comprises the support means cooperating with a chimney.

Preferably the support means comprises a tube fixed on the bottom of the basket whose diameter is substantially greater than that of the chimney, said tube being closed at an upper end and open at a lower end so that the tube is able to receive the chimney and so rest on it.

The tube may thus comprise one or more openings in a section adjacent to its upper end so as to let the gas phase spread inside the chimneys. In one embodiment, the tube is permeable to the liquid phase and possibly capable of retaining the solid phase constituted by the filter medium. The tube is porous over its height so as to also allow the passage in the chimneys of the liquid phase accumulated at the level of the filter medium. For example the openings are distributed over the height of the tube with a regular pitch between the openings. Alternatively, the tube is made from a perforated grid, for example of the Johnson type.

According to an alternative embodiment, the support means comprises a plurality of vertical arms fixed on the bottom of the basket and equipped with hooking means configured to cooperate with the chimney.

Preferably the bottom of the baskets is permeable to the liquid phase and the height h of the support means is less than the height H of the chimneys so as to create a collection space of the liquid phase between the bottom of the baskets and the tray. This embodiment is advantageous because it makes it possible to provide a liquid collection zone in which the purified liquid phase is mixed before being distributed on the catalytic bed via the stacks. In this embodiment, the openings of the chimneys are essentially located in the liquid collection zone and the support means are not necessarily permeable to the liquid.

According to a preferred embodiment, the baskets are delimited by a stack of the tray located at each end of the sides of the basket.

Preferably, the baskets located at the periphery of said device have at least one side wall having a curvature. This embodiment makes it possible to produce a device that can match the curvature of the wall of the reactor in which it is installed so as to cover the reactor section in a compact manner.

Preferably, two adjacent baskets are separated by a free space or functional game so as to allow their introduction and basket withdrawal basket. For example, this free space is between 1 and 20 mm, preferably between 1 and 10 mm.

The present invention also relates to a reactor operating at a co-current downflow of gas and liquid comprising: • a fixed catalytic bed; and a device for filtering and distributing a gas phase and a liquid phase according to the invention arranged upstream of the catalytic bed; At least one layer of filtration means arranged in the baskets, it being understood that the upper end of the chimneys is situated above the upper filtering layer.

The reactor according to the invention is, for example, a reactor operating in trickling flow at a co-downflow of gas and liquid with a liquid velocity of between 0.1 and 5 cm / s, for example between 0.1 and 1 cm. / s (in the case of hydrotreating reactors) or between 1.1 and 5 cm / s (in the case of selective hydrogenation reactors).

Preferably, the filtration and distribution device is arranged in the reactor so that an annular zone is left free between the walls of the peripheral baskets adjacent to the reactor wall. For example, the annular zone corresponds to 2% to 50%, and preferably 5% to 20% of the reactor section.

According to the invention, the baskets can contain several layers of filter media.

Advantageously, the filtration and distribution device arranged in the reactor comprises at least one perforated removable protective grid disposed above the upper filter media layer. This protection grid makes it possible to protect the filter media from the arrival of the gas / liquid flow entering the reactor and thus to prevent any projection of particles constituting the upper filter media layer. In the context of the invention, the device may also comprise a removable rack by basket thus allowing a withdrawal of the full baskets by orienting them at an angle relative to the horizontal to facilitate their passage through an outlet orifice made in the reactor (for example a manhole).

Preferably and for reasons of ease of handling, the removable baskets have a dimension smaller than that of a manhole practiced in the reactor. The main application is the catalytic treatment of heavy petroleum cuts, even if the present invention can be applied to any hydrogenation of petroleum fractions loaded with clogging particles or precursors of coke formation, which can cause clogging of the bed. fixed.

Detailed description of the invention

The other features and advantages of the invention will become apparent on reading the following description, given solely by way of illustration and without limitation, and with reference to the drawings in which: FIG. 1 is a diagrammatic sectional view of a reactor operating at a co-downflow of gas and liquid including a filtration and distribution device arranged upstream of a fixed catalytic bed; FIG. 2 is a detailed profile view of a distributor plate of a filtration and dispensing device according to the invention; FIG. 3 is a detailed profile view of a set of baskets of a filtration and dispensing device according to the invention; FIGS. 4 to 6 are views, along a horizontal plane passing through the line (AA ') of FIG. 1, of a set of filtration baskets of a filtration and dispensing device according to the invention. similar elements are denoted by identical references in the figures.

The present invention relates to a filtration and distribution device for feeding a catalytic reactor operating on a gas and liquid charge, more particularly in a flow regime called trickle regime, ie with a superficial velocity liquid between 0.1 cm / s and 5 cm / s.

With reference to FIG. 1, the filtration and distribution device 1 of a gaseous phase and of a liquid phase is disposed in a catalytic reactor 2, operating at a co-downflow of gas and liquid, whose enclosure is delimited by a wall 3 generally of circular section. The device 1 is arranged upstream of a fixed catalytic bed 4. The device according to the invention can be defined as a distributor plate whose function is to transform the two-phase jet entering the reactor into a gas / liquid mixture uniformly distributed over the surface of the catalytic bed placed downstream of said tray and which also incorporates a filtration function by the establishment of a filter layer.

Referring to Figures 1 and 2, the device 1 comprises a distributor plate 5 which comprises a solid plate 6 (also called solid plate 6) on which are fixed distribution means 7 of a biphasic gas / liquid mixture. The distribution means 7 which pass through the solid plate 6 are in the form of vertical chimneys 7 closed at their upper end 8 and open at their lower end 9 and perforated with lateral orifices 10 (also called openings here) distributed over the height chimneys 7 whose function is detailed below. It should be noted that, alternatively, the openings 10 made in the chimneys 7 may be replaced by one or more slots. Each chimney 7 further comprises a lateral opening located below its upper closed end 8 to allow the introduction of the gas phase.

Preferably, the distributor plate 5 is configured such that the solid plate 6 has a section that corresponds to that of the reactor enclosure. Thus, if the reactor is of circular section, the size of the section of the solid plate corresponds to that of the internal diameter of the reactor.

As indicated in FIGS. 1 and 2, the lower end 9 of the chimneys 7 opens at or below the solid plate 6 and above the fixed catalyst bed 4. Preferably, the reactor further comprises a dispersive element 11 arranged below the distributor plate 5 whose function is to break up and disperse the jet of gas / liquid mixture which is expelled from the lower end 9 of the chimneys 7. With reference to FIG. 2, it will be noted that the upper end 8 open chimneys 7 is capped with a deflector element 12 which prevents the introduction of the liquid phase through the opening of the upper end 8 but allows the gas phase to pass into the lateral zone of the upper part.

According to the invention, the device 1 also incorporates a filtration function provided by a plurality of filter baskets arranged above the distributor plate 5 and which are supported by the latter.

As shown in Figure 3, the filter baskets are composed of a bottom 13 which supports at least three side walls 14 substantially vertical. The vertical walls 14 and the bottom 13 are porous to be permeable to the liquid phase while retaining the filter media 15. The vertical walls 14 and the bottom 13 may be formed by a metal grid, for example of the Johnson type known from the one skilled in the art, or a metal plate pierced with orifices whose mesh size of the grid or orifices is such that it is strictly smaller than the average dimension of the elements constituting the filter media carried by the basket.

According to the invention and with reference to Figures 1 and 3, the basket further comprises at least one support means 16 of the basket cooperating with at least one chimney 7 of the distributor plate 5. In the example of Figure 3, the support means 16 is in the form of a tube fixed on the bottom of the basket and whose diameter is substantially greater than that of the chimney 7. The tube is closed at its upper end by a plate 17 and open at its end lower 20 so that the tube is adapted to receive the chimney. Once the basket is in place, that rests on the chimney 7 via the plate 17. It will be noted moreover that the section which is adjacent to the upper end of the tube 16 comprises openings 21 which are in communication with the open upper end of the chimney on which it is mounted so as to allow the passage of the gas flow in the tube 16 and in the chimney 7 of the distributor plate. In a particular embodiment, when the chimneys are provided with orifices distributed over their height, the tubes are also porous over at least the lower half of their height and preferably over their entire height to allow the passage of the purified liquid phase. from the filter baskets in the distribution stacks. According to another alternative embodiment not shown, the support means is in the form of vertical arms fixed to the bottom of the basket and said arms are equipped with hooking means configured to cooperate with the chimney, for example at the level of the upper opening of the chimney or on any level of the height of the chimney.

The horizontal section delimited by the vertical walls 14 may be triangular (in the case of three vertical walls) as shown in FIG. 4, circular (in particular case of a vertical wall of ellipsoidal shape) as shown in FIG. 6, or hexagonal (case six vertical walls) as shown in Figure 5.

FIG. 1 represents a particular embodiment of the filtration and dispensing device in which the bottom 13 of the baskets is permeable to the liquid phase and in which the height h between the bottom of the basket and the upper end of the support means 16 is less than the height H of the chimneys so as to create a collection space E of the liquid phase (also called mixing zone of the liquid E) between the bottom 13 of the baskets and the distributor plate 5. It will be noted that in this mode of The chimney openings are located essentially in the collection space so as to communicate with it and the walls of the basket support tubes 16 are not necessarily permeable to the liquid, for example the walls of the tubes are solid. .

Note that, as also shown in Figure 1, the openings 10 chimneys 7 may be present on most of the height of the chimneys 7 so that said openings 10 are located in the filter media layer 15. This allows when the support means is permeable to the liquid to maintain the distribution of the liquid as and when the clogging, since the set of chimneys 7 is still used, and that the liquid flow remains approximately identical between the chimneys, the latter being essentially conditioned by the liquid level established within the filtration baskets. The distribution of the liquid therefore remains controlled throughout the life of the filter bed, and the progressive use of the lateral or lateral slots distributed throughout the chimneys, allows the use of the filter bed up to its complete saturation, without rise of the pressure gradient which would force the shutdown of the reactor.

Preferably and as indicated in FIG. 1, the section developed by all the filter baskets of the device does not occupy the entire section of the reactor. There is indeed an annular space 18 between the filtration zone baskets called "periphery" and the wall 3 of the reactor. This annular space 18 allows the passage of the liquid in the collection zone E and then to the distribution means 7 even in the situation where the filter media is clogged by the various impurities recovered over time.

In the case where the filtration function is no longer provided by the filter baskets, the distribution plate continues to operate through the openings 10 of the chimney elements 7 which are located in the mixing zone of the liquid E.

The width of this annular space is set so that the pressure balance is respected even in the case where the tray is completely clogged. Preferably the annular zone 18 corresponds to 2% to 50%, and preferably 5% to 20% of the reactor section. When the filtration and distribution device is used in a reactor, the filter baskets are filled with water. one or more filter media layers 15. For example, the filter media layer 15 may comprise so-called protective elements, on a height which is generally between 100 mm and 450 mm, and preferably between 100 and 300 mm.

The protective elements constituting said layer may be: particles of guard material or any other particles generally serving as protection elements, for example sold by the company Axens, a catalyst support or a catalyst.

Any material capable of retaining the clogging particles contained in the charge may be suitable for the device according to the present invention, such as a crosslinked ceramic or metallic material, for example marketed by the companies Unicat or Crystaphase. These crosslinked materials may be in the form of a wafer of circular section 3 to 5 cm in diameter and height of between 1 to 3 cm.

It should be noted that the filter elements can take different forms such as for example balls, multilobed cylinders, single cylinders, hollow tube or cart-shaped wheel; this list is not exhaustive.

In most cases, only one layer of filter media is sufficient. Nevertheless, for filter media heights greater than 200 mm, it is possible to use several layers and with the size of the filter elements of a given layer which is smaller than that of the filter elements constituting the next higher layer.

However, for the implementation of the device in a reactor, it will be ensured that at the end of the loading of the filter media 15, the upper end of the distribution funnels 7 is located above the upper layer of filtering media so as to do not interfere with the passage of the gas phase inside the stack of the distributor plate.

As indicated in FIG. 1, the device preferably comprises a perforated protection grid 19 disposed above the upper layer of filter medium 15. This protective grid makes it possible to protect the filter media from the arrival of the gas / liquid flow. entering the reactor to prevent any projection of particles constituting the upper layer of filter media and also facilitates loading / unloading facilitated by inclination relative to the horizontal.

According to another embodiment of the filtration and distribution device, the height h of the support means is substantially equal to the height H of the chimneys so as not to create a collection space E of the liquid phase between the bottom of the baskets and in this embodiment, the support means 16 of the basket are permeable to the liquid over at least the lower half of their height and preferably on the major part of their height and the lateral openings 10 chimneys are distributed over at least the lower half of the height of the chimney and preferably over most of the height of said chimneys 7. Since in this embodiment the bottom 13 baskets rests on the full tray 6, the bottom 13 does not need to be permeable to the liquid.

The operation of the filtering and dispensing device installed in a co-current flow reactor descending a gas phase and a liquid phase is described below with reference to FIG. 1. In general, the filtering plate according to FIG. The invention is at least positioned upstream of the first catalytic bed 4 (in the direction of fluid flow). When the biphasic charge gas / liquid is introduced staggered on different catalytic beds staggered along the reactor, it is possible to position a device according to the invention upstream of each of the catalyst beds.

The gas / liquid mixture is sent to the top of the device according to the invention as indicated by the arrow G / L. The gaseous fraction of the mixture which enters the chimneys 7 through the upper openings after passing through the upper openings 21 of the support means 16, is directed under the solid plate 6. As for the liquid fraction which is prevented from passing into the part upper chimneys by the deflector elements 12 (see Figure 2), it is collected in the filter baskets and percolates through the layer or layers of filter media contained in the baskets. The contacting of the liquid phase with the filtration elements makes it possible to retain the particles responsible for fouling the catalytic bed so as to provide a so-called "purified" liquid which diffuses through the holes in the bottom of the baskets.

The purified liquid is thus collected in the collection space E which is occupied only by liquid since during normal operation of the reactor, the liquid level above the plate 6 is located inside the media layer. 15 and below the upper end of the chimneys 7 which are only accessible to gas. The purified liquid accumulated in the collection space E then diffuses into the chimneys through the openings 10 opening into this space and is mixed with the gas phase which circulates in the chimneys 7. The purified gas / liquid mixture is removed from the chimneys 7 by their lower opening 9 under the solid plate 6. The gas / liquid mixture jet is then dispersed when it meets the dispersive element (s) 11 arranged between the catalytic bed 4 and the solid plate 6.

In a particular embodiment, the chimneys also comprise orifices which are located in an area corresponding to the height of the filter medium and the support means 16 (tube) are porous in the liquid phase so that the purified liquid is able to diffuse directly from the filtration zone in the chimneys passing through the tubes.

The operating mode of a filtration and dispensing device according to the invention in which the bottom 13 of the baskets, possibly full, rest on the plate 6 is similar to that described above with the difference that the purified liquid is not does not evacuate baskets by their bottom but diffuses through the support means 16 and in the chimneys 7 via the side orifices 10 of the latter.

Figures 4 to 6 which are sectional views along the horizontal plane passing through the line (AA ') of Figure 1 show different forms that can take the filter baskets that are supported by the chimneys 7 of the distributor plate.

It is observed that the filtration baskets according to the invention comprise at least three vertical side walls 14 which delimit the section of the basket. The baskets that have a wall adjacent to the reactor wall may have some of their wall bending that matches that of the reactor wall. The horizontal section delimited by the vertical walls may be triangular (in the case of three vertical walls) as shown in FIG. 4 or hexagonal (in the case of six vertical walls) as shown in FIG. 5. In these preferred embodiments, all the baskets are traversed by at least one chimney with which the support means of the basket cooperates.

As indicated in FIGS. 4 and 5, the baskets have their angles which are limited by a chimney of the distributor plate. Thus in the case of Figure 4, the triangular basket is crossed by a central chimney, with a chimney at each corner. In Figure 5, the basket is hexagonal and is crossed by a chimney in the center, and six chimneys, one at each angle of the hexagon.

Alternatively and as shown in Figure 6, the baskets are delimited by a vertical wall of circular shape which is a special case of an ellipse.

In the cases where the baskets used do not have a vertical wall in the form of an ellipse, baskets that have none of their wall in contact with the reactor wall and which are called central baskets are distinguished. baskets which have part of their walls adjacent to the reactor wall and which is designated by peripheral baskets. The peripheral baskets may have at least one curved side wall conforming to the shape of the wall 3 of the reactor while the central baskets have straight vertical walls.

Another alternative embodiment not shown involves baskets whose angles are limited by a chimney and whose bottom is not crossed by a chimney of the distributor plate. In this case, the support means of the basket are carried by the side walls of the baskets and may take the form of curved fins forming a hook adapted to hook to the chimney.

In general, all of the baskets are adjusted so as to cover the entire section of the reactor leaving only a free space or functional clearance between the side walls of the adjacent baskets so as to allow their insertion or withdrawal movement individually. , ie basket by basket.

The filtering and dispensing device according to the present invention is applicable to processes for hydrotreatment, selective hydrogenation, residue conversion, or oxidation of petroleum fractions. Heavy loads that can be processed using the present tray filter dispenser can be defined as those whose boiling point is greater than 370 ° C, especially of residue or related type: atmospheric residues, residues in vacuums, deasphalted oils, or residues resulting from conversion processes such as for example the coking, hydrotreating in fixed bed, bubbling bed, or moving bed, all these types of residues can be taken alone or mixed.

These heavy charges can be used as such or diluted by a hydrocarbon fraction or a mixture of hydrocarbon fractions.

The heavy feeds affected by the present invention may also include cuts from the process of liquefying coal, aromatic extracts, or any other hydrocarbon cuts.

Example

An illustrative dimensioning example of a filtration and dispensing device according to the invention with reference to FIG. 5 for a reactor of 5.5 m internal diameter is described below.

The characteristics of the distributor plate that supports 1149 vertical chimneys are as follows: - Diameter of the solid plate: 5.5 m The dimensions of the vertical chimneys are: - Height of the chimneys: 440 mm from the solid plate - External diameter of the chimneys: 50 mm - Not between chimneys: 150 mm

The chimneys have two rows of orifices for the admission of the liquid: - Row 1 of orifices: height with respect to the plate full of 40 mm, 3 holes of 5 mm - Row 2 of orifices: height compared to the plate full 130 mm, 3 holes 5 mm - Opening for the passage of gas at the top of the chimney for the admission of the gas is 50 mm

The device further comprises 383 hexagonal section baskets that can receive a chimney at each corner of the hexagon. The dimensions of the basket are: - Side of the hexagon: 95 mm - Height of the vertical walls: 240 mm

The hexagonal bottom of each basket is provided with a central orifice surmounted by a tube closed at its upper end and into which a distribution chimney is introduced. The dimensions of the tube are: - Internal diameter of the tube: 55 mm - Height of the tube: 300 mm

The baskets are thus supported via the central tube which rests on the chimney. The bottom of the baskets are located at a distance of 140 mm above the full tray of the distributor plate so as to define a mixing space for the purified liquid phase having a height of 140 mm.

The baskets can thus contain a filter medium, composed of one or two layers, whose thickness is 230 mm measured from the bottom of the basket.

Claims (15)

1. Apparatus for filtering and distributing (1) a gaseous phase and a liquid phase, capable of being disposed upstream of a fixed catalytic bed (4) of a reactor (2) operating in a cocurrent descending gas and liquid, comprising: • a solid plate (6) extending in a horizontal plane on which are fixed substantially vertical chimneys (7) open at their upper and lower end, said chimneys (7) being provided with openings (10) over at least a fraction of their height; A plurality of removable baskets capable of containing and retaining a filtering medium, each removable basket being defined by an ellipsoidal vertical wall (14) or by at least three vertical lateral walls (14) and a bottom (13), the vertical walls and / or the bottom being permeable to gas and liquid and wherein each basket is provided with at least one support means (16) of the basket cooperating with a stack of the tray to support the filter basket. 2. Device according to claim 1, wherein the bottom (13) of the basket is traversed by at least one chimney (7) and the support means (16) cooperates with the chimney passing through the bottom. 3. Device according to claims 1 or 2, wherein at least one of the side walls (14) comprises the support means cooperating with a chimney. 4. Device according to claims 1 or 2, wherein the support means (16) comprises a tube fixed on the bottom of the basket whose diameter is substantially greater than that of the chimney, said tube being closed at an upper end (17). ) and open at a lower end (20) so that the tube is adapted to receive the chimney (7). 5. Device according to one of claims 1 to 3, wherein the support means (16) comprises a plurality of vertical arms fixed to the bottom of the basket and said arms are equipped with hooking means configured to cooperate with a chimney ( 7). 6. Device according to claim 4, wherein the tube (16) is permeable to the liquid phase. 7. Device according to one of the preceding claims, wherein the bottom (13) of the baskets is permeable to the liquid phase and the height h of the support means is less than the height H of the chimneys so as to create a collection space (E) of the liquid phase between the bottom of the baskets and the solid plate (6). 8. Device according to one of the preceding claims, wherein the baskets are defined by a stack of the tray located at each end of the sides of the basket. 9. Device according to one of the preceding claims, wherein baskets at the periphery of said device have at least one side wall (14) having a curvature. 10. Device according to one of the preceding claims, wherein two adjacent baskets are separated by a free space so as to allow their introduction and basket withdrawal basket. 11. Reactor (2) operating downwardly co-current of gas and liquid comprising in the flow direction fluids: • a fixed catalytic bed (4); and a device for filtering and distributing (1) a gaseous phase and a liquid phase according to any one of the preceding claims arranged upstream of the catalytic bed (4); At least one layer of filter medium (15) arranged in the baskets, it being understood that the upper end (17) of the chimneys (7) is situated above the filter media layer (15). 12. Reactor according to claim 11 wherein the device is arranged in the reactor so that an annular zone (18) is left free between the walls (14) of the peripheral baskets adjacent to the reactor wall. 13. Reactor according to claim 11 or 12, wherein the baskets contain several superposed layers of filter media. 14. Reactor according to one of claims 11 to 13, wherein the device comprises a perforated protective grid (19) disposed above the upper layer of filter media. 15. Reactor according to one of claims 11 to 14, wherein the removable baskets have a dimension smaller than that of a manhole practiced in the reactor.