Filtration equipment for beverage extraction

Abstract

A filtering device (10) for extracting a beverage (B) by percolation, the filtering device (10) comprising a tubular body (11) and a support (12) for accommodating a filter (13) in which a powdered product (C) is placed.

Description

Field of invention

[0001] The present invention relates to a filtering device for extracting beverages, in particular by percolation. The filtering device can be used in particular for preparing coffee or other beverages, such as tea or herbal tea, from powdered or granular products. The following description is particularly directed to the preparation of coffee. Background of the invention

[0002] As is well known, there are various methods for obtaining a coffee beverage from a powdered product, such as using a coffee machine or coffee maker, or by percolation or infusion using a container and a filtering device.

[0003] Brewing coffee by percolation essentially involves pouring hot water over coffee grounds and forcing the beverage through a filter made of paper, cloth, metal, plastic, etc., to collect in a container below. Using a technique known as "pour-over," the hot water is forced through the coffee grounds held in the filter using gravity alone.

[0004] Infusion, on the other hand, is achieved by pouring hot water into a container and letting the ground coffee steep for a few minutes. After the required extraction time, the liquid is separated from the ground coffee in a filter to obtain the beverage.

[0005] The method of preparing beverages with an osmotic filtration system is known in the state of the art as "V60", a name derived from the apex angle characteristic of both the conical container and the disposable paper filter.

[0006] This percolation filtration system is essentially instantaneous, i.e. the water passes quickly through the coffee powder and is in contact with it for only a very limited time, therefore this system does not result in a beverage with optimal organoleptic properties, since the water does not come into contact with the coffee powder for a sufficient time to satisfactorily absorb the coffee's inherent organoleptic properties.

[0007] Furthermore, such percolation filtration systems require considerable skill from the user, who must ensure that the liquid is distributed as evenly as possible over the powdered product, avoiding the occurrence of bypassing, where the liquid passes through the top of the filter where the powdered product is not present, and channeling, where the liquid is not distributed evenly within the powdered product but enters the product with such forces that it defines preferential passage channels. Clearly, these phenomena result in uneven extraction of the beverage, which impairs its quality.

[0008] A further mode for preparing coffee by percolation is described in document US-B-7849784. In this mode, a filtering device is arranged above the container. This filtering device uses a cylinder, the lower end of which, close to the container, is arranged with a filter containing coffee powder. This lower end is formed as a grid on which the filter rests. In this cylinder, a certain amount of water is poured onto the coffee powder, and this water is forced onto the coffee powder by a piston insertable from the top of the cylinder, which is arranged to exert a certain pressure on the air located above the amount of water.

[0009] This system is very complex and requires various tools for its implementation, such as a cylinder and a piston. Furthermore, again, the contact time of the water passing through the coffee powder is quite limited. The user must apply a certain pressure to the piston every time they prepare a beverage. The presence of the grid is necessary, on the one hand, to prevent the filter from being pushed out of the cylinder by the pressure of the piston, but, on the other hand, it creates an obstacle that hinders the flow of beverage, which increases the pressure that the user must apply to the piston to extract the beverage.

[0010] Document WO 2007 / 119546A describes a coffee brewer consisting essentially of two overlapping containers. One container supplies water at the top, while the other collects coffee at the bottom. A filter holder containing the coffee powder is also located between the two containers, forming a closed chamber containing the coffee. This construction inevitably leads to the coffee powder being compressed in the closed chamber, resulting in the formation of coffee lumps. This is, of course, undesirable, since the more the powder is compressed, the more difficult it is to properly and completely extract the beverage. To achieve proper and complete extraction of the beverage, the water must be evenly distributed in the chamber and all coffee powder grains must be in contact with the water for the time required to ensure extraction of the beverage.

[0011] The extractor is rather bulky, for example, because the filter holder is placed at a certain distance from the water container at the top: the water container and the filter holder are separated by a vertical conduit several centimetres long.

[0012] The extractor is structurally multi-part, rather complex to assemble and does not allow for optimally uniform distribution of water to the product in the filter holder.

[0013] Due to the presence of a vertical water supply conduit, water reaches the filter holder at different pressures and velocities in the center and the area around the circular edge of the filter holder. In particular, in the area directly below the conduit, the water pressure and velocity are so high that holes are created in the coffee mass, allowing the water to flow preferentially. The water flows quickly through these holes without stopping for the time required to complete the extraction.

[0014] Furthermore, since the extractor comprises a paper filter supported by a grid, there is an area below the filter that creates resistance to the free passage of the beverage.

[0015] The structure of the extractor described in WO2007 / 119546 not only creates hydraulic resistance to the forward movement of the liquid, but also creates preferential channels for extraction, resulting in the phenomenon of channelling.

[0016] Another well-known method for obtaining a coffee beverage uses a sealed, preferably sealed, capsule containing a predetermined amount of coffee powder, which is placed in a special beverage brewing machine through which hot water is passed. Examples of capsules of this type are described in the prior art documents KR20120114736A and WO2015 / 124534A.

[0017] There is therefore a need to develop a filtering device for beverage extraction that overcomes at least one of the drawbacks of the state of the art.

[0018] In particular, one of the objects of the present invention is to provide a filtering device for brewing beverages that is easy to manufacture and use.

[0019] Another object of the invention is to provide a filtration device that allows for a slower and more gradual extraction of the beverage, with improved organoleptic properties, compared to known systems.

[0020] Another object of the invention is to provide a filtering device in which the beverage is obtained substantially by gravity in such a way that the water passes reasonably slowly through the coffee grounds disposed on the filter.

[0021] Another object of the invention is to provide a filtering device that allows for uniform extraction of the beverage and ensures that the liquid uniformly wets the coffee grounds.

[0022] Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to achieve or obtain these and other objects and advantages. Summary of the Invention

[0023] The invention is set out and characterized in the independent claims, while the dependent claims describe other features of the invention or variants of the main idea.

[0024] In accordance with the above object, a filtering device for beverage extraction according to the present invention comprises a tubular body and a support for accommodating a filter in which a powdered product such as coffee powder is placed.

[0025] According to some embodiments, the tubular body is open at the top, which on the one hand facilitates the use of the filtering device and on the other hand means that the powder product remains randomly arranged without compaction when it falls and deposits, which is advantageous compared to solutions known from the state of the art in which the powder is contained in a closed chamber, which inevitably compacts the powder and impairs the extraction efficiency of the beverage.

[0026] According to a characteristic aspect of the present invention, the filtering device includes a chamber for containing a liquid, particularly hot water, outside the tubular body. The chamber has a bottom located at a height higher than the height of the filter and is fluidly connected to the tubular body by a plurality of through-holes, allowing the liquid to pass by gravity from the chamber to the tubular body and thus to the powder product. Furthermore, the chamber is annular and is arranged around the tubular body.

[0027] According to some embodiments described herein, the annular chamber is open at the top.

[0028] The separation between the chamber containing the liquid and the tubular body containing the powdered product, e.g. coffee powder, allows the liquid, in particular hot water, to pass through the powdered product for a longer time, which has the advantage that a beverage with better sensory properties can be obtained by infiltration compared to beverages obtained with conventional devices.

[0029] The device also has the advantages of being compact, easy to manufacture, and not requiring the user to use a cylinder, piston, or the like.

[0030] The annular shape of the chamber allows the extracted beverage to be evenly distributed around the filter and therefore around the powdered product, further increasing the uniformity of contact with and passage through the product.

[0031] According to another aspect of the invention, the chambers are arranged concentrically around the tubular body, in this way the hot water penetrates the coffee grounds laterally, promoting uniform extraction all around the circumference of the beverage.

[0032] According to another aspect of the invention, the chamber has a truncated cone shape with a cross section that decreases from the top opening to the bottom.

[0033] According to another aspect of the invention, the bottom slopes downwards towards the tubular body and the through-hole, this detail making it possible to avoid for example possible phenomena of liquid stagnation.

[0034] According to another aspect of the invention, the through holes are uniformly distributed on the tubular body, and may be radially oriented or have a tangential component.

[0035] According to another aspect of the present invention, the through-hole is inclined downward toward the inside of the tubular body.

[0036] According to another aspect of the invention, the through-hole is located near the bottom of the chamber.

[0037] According to another aspect of the present invention, the through-hole has a cylindrical shape.

[0038] According to another aspect of the present invention, the through-hole has a truncated cone shape, with a larger cross section on the inlet side of the liquid and a smaller cross section on the outlet side.

[0039] These holes can be sized to provide a uniform extraction and beverages requiring less powdered product, e.g., coffee powder, for the same total dissolved solids (TDS) compared to current commercial preparation methods.

[0040] According to another aspect of the invention, the tubular body can be screwed onto the support and integrated with the chamber.

[0041] According to another aspect of the invention, means for holding the filter in place are arranged between the tubular body and the support, these means may be, for example, a labyrinth system, a gasket, etc. [Brief explanation of the drawings]

[0042] These and other aspects, features and advantages of the invention will become apparent from the following description of some embodiments thereof, given by way of non-limiting example with reference to the accompanying drawings, in which: FIG. 1 is a longitudinal sectional view of a filtering device for beverage extraction according to the invention, arranged above a container for collecting the extracted beverage. FIG. 2 is a three-dimensional top view of the filtration device. FIG. 3 is a three-dimensional bottom view of the filtration device. FIG. 4 is a longitudinal cross-sectional view of a portion of the filter device provided with holes for the passage of liquid. FIG. 5 is a longitudinal cross-sectional view of a variation of the hole of FIG. FIG. 6 is a cross-sectional view of the tubular body of the present filtering device, which is designed to correspond to the through holes for the passage of liquid. FIG. 7 is another cross-sectional view of a tubular body in which the through holes are provided in a different configuration. FIG. 8 is a longitudinal cross-sectional view of a modification of the present filtering device. FIG. 8a is an enlarged view of a detail of the filtration device of FIG. FIG. 9 is a longitudinal cross-sectional view of another variation of the present filtering device. FIG. 9a is an enlarged view of a detail of the filtration device of FIG.

[0043] It should be clear that the expressions and terms used in this specification, as well as the figures in the accompanying drawings, are merely intended to better illustrate and explain the invention, and to provide non-limiting examples of the invention itself, the scope of protection of which is defined by the claims.

[0044] For ease of understanding, the same reference numerals have been used wherever possible to identify identical common elements in the drawings. It will be understood that elements and features of one embodiment may be conveniently combined or incorporated in other embodiments without further description. DESCRIPTION OF SOME EMBODIMENTS OF THE INVENTION

[0045] Reference will now be made in detail to possible embodiments of the invention, one or more examples of which are illustrated by way of non-limiting example in the accompanying drawings. The phraseology and terminology used herein is also for purposes of non-limiting example.

[0046] With reference to the accompanying drawings, in particular Figures 1, 2 and 3, a filtering device (10) for extracting a beverage (B) comprises a tubular body (11) and a support (12) for accommodating a filter (13) on which a powdered product (C), such as ground coffee or a preparation such as coffee, tea, herbal tea, etc., is placed. The support (12) is particularly arranged at the lower end of the tubular body (11). The support (12) may, for example, comprise an annular step (31) protruding inward from the lower end of the tubular body (11).

[0047] The filtering device (10) comprises a chamber (14) for containing a liquid (W), in particular hot water, outside the tubular body (11). The chamber (14) is provided with a bottom (15) that is higher than the height of the filter (13) and is fluidly connected to the tubular body (11) by a number of through holes (16) that allow the liquid (W) to pass by gravity from the chamber (14) to the tubular body (11) and thus to the powdered product (C).

[0048] The filter (13) can be made of plastic, metal, etc. and consists of a series of appropriately sized through holes (17). Alternatively, a paper filter (25) can be provided as shown in Figure 8 or Figure 9.

[0049] The filtering device (10) is placed over a container (18) in which the filtered beverage (B) is collected. The container (18) can be of any suitable size, such as a cup, pitcher, or other type known in the art, that can stably accommodate the filtering device (10).

[0050] In the example shown, the filter device (10) includes a flange (19) that is configured to rest on the top of a container (18) during use.

[0051] The flange (19) is concentrically disposed around the tubular body (11).

[0052] The flange 19 is provided with an annular step 20 configured to allow the filter device 10 to rest stably on the container 18. Of course, it would be possible to provide a different mounting system without the flange 19 and annular step 20.

[0053] In other embodiments, not shown, other temporary and removable coupling systems can be provided between the filter 10 and the container 18. By way of non-limiting example, the filter 10 can be provided with threads that allow the filter 10 to be screwed into a corresponding container 18, which in turn is provided with threads. Alternatively, a mechanical conformal coupling, such as a male-female interference coupling, can be provided, in particular an annular ridge that engages with a corresponding groove.

[0054] An annular recess 21 is provided between the tubular body 11 and the flange 19. A rib 22 is disposed in the annular recess 21. The rib 22 serves to place the filter device 10 on the container 18 when the flange 19 and the step 20 are not provided. The rib 22 also serves to provide an escape route for water vapor generated in the beverage B, thereby preventing condensation. Furthermore, the rib 22 also serves to strengthen the filter device 10.

[0055] The chamber (14) into which the hot water is poured by the user is annular and is arranged around the tubular body (11). In particular, the chamber (14) is arranged continuously around the tubular body (11). This allows, for example, the hot water to impinge on the powdered product (C) from 360° through the through holes (16), thus ensuring optimal uniformity of contact and passage with the powder.

[0056] The chamber (14) is arranged concentrically around the tubular body (11) and therefore has a uniform width around the tubular body (11).

[0057] The chamber (14) preferably has a truncated conical shape, in particular a shape with a cross section that decreases from the top opening (24) to the bottom (15), which ensures a better distribution of the hot water into the through holes (16).

[0058] The tubular body (11) may comprise a first portion (11a) having a truncated conical cross section tapering from the respective upper opening (23) through which the powdered product (C) is introduced, and a second portion (11b) having a cylindrical cross section reaching close to the support (12) of the filter (13).

[0059] In the example described here, the top opening (24) of the chamber (14) and the top opening (23) of the tubular body (11) are exposed to the surrounding environment, so that both the chamber (14) and the tubular body (11) are open, thereby avoiding the creation of overpressure that could compress the coffee powder and give hot water parameters (pressure, speed) that are not suitable for achieving effective extraction.

[0060] The support 12 is integral with the chamber 14 and includes an annular wall 26 that may be formed with threads 27 configured to engage with corresponding counter-threads 28 formed in the second portion 11b. In this manner, the tubular body 11 can essentially be threaded into and unthreaded from the support 12, and therefore from the chamber 14.

[0061] Thus, the filtration device 10 can be made in two parts, for example, a tubular body 11 and a chamber 14 with a support 12 for threading the tubular body 11. These two parts can be made of a plastic or thermoplastic material such as polypropylene, a metal material, or other materials.

[0062] The bottom (15) of the chamber (14) slopes downwards towards the tubular body (11) and the through-holes (16), which allows water to pass through them easily and allows the chamber (14) to be emptied efficiently.

[0063] The through holes (16) are located near the bottom (15) so that all the water poured into the chamber (14) can be utilized.

[0064] To ensure a more uniform distribution of water into the powdered product (C), the through holes (16) are evenly spaced over the tubular body (11), thus equally spaced 360° apart.

[0065] The through holes (16) may be inclined downward toward the inside of the tubular body (11) or may be oriented horizontally, as shown in Figure 4. In either case, it is preferable that the through holes (16) have a certain degree of inclination to facilitate the outflow of water.

[0066] The through-hole (16) can be cylindrical as shown in Figure 4, or frusto-conical as shown in Figure 5 as shown in Figure 6. In this case, the through-hole (16') has a larger cross section on the inlet side of the liquid (W) and a smaller cross section on the outlet side.

[0067] The through holes (16 or 16') can be radially oriented, as illustrated in FIG. 6, or can be provided with a tangential component (see holes (16") in FIG. 7). The tangential component generates a flow that helps to further improve the uniformity of the contact between the liquid (W) and the powdered product (C). In fact, the tangential component makes this flow spirally, improving the distribution of the liquid in the powdered product (C).

[0068] Thus, in some embodiments of the invention, the through-holes may have the shape of a truncated cone providing a certain slope to facilitate the outflow of liquid, for example, hole (16') in FIG. 5, and at the same time may have a certain tangential component, for example, hole (16") in FIG. 7, or may have only one of such slopes / components.

[0069] 8 and 8a show a variation (10a) of the present filtering device, which includes a paper filter (25) whose bottom is placed between the end (29) of the tubular body (11) and the support (12). Specifically, the end (29) and the support (12) are shaped to engage with each other and form a labyrinth system (30) for fixing the filter (25), particularly its peripheral portion, in place. Specifically, the labyrinth system (30) can include one or more projections (33) and one or more recesses (34) on the end (29) and the support (12), which can be interlocked when the tubular body (11) is fully screwed onto the support (12).

[0070] Thus, the user would place the filter (25) on the annular step (31) before threading the tubular body (11) onto the annular wall (26) of the support (12). The tubular body (11) would then be threaded onto the support (12), also fixing the position of the filter (25). At this point, the required amount of powdered product (C) can be poured into the filter (25).

[0071] 9 and 9a show another variation (10b) of the present filtering device, in which the opposing surfaces of the end (29) and the support (12) are substantially flat and spaced apart, with a gasket (32) disposed therebetween for clamping the filter (25). Specifically, when the tubular body (11) is threaded onto the support (12), the peripheral portion of the filter (25) remains sandwiched between the gasket (32) and the annular step (31) of the support (12).

[0072] Thus, the labyrinth system (30) and the gasket (32) are two examples of means for holding the filter (25) in place between the tubular body (11) and the support (12).

[0073] The user places the filtering device (10, 10a, 10b) in a container (18), such as a pitcher or cup, and then pours the required amount of powdered product (C) into the filter (13). Next, a liquid (W), specifically hot water, is poured into the chamber (14). This hot water passes through the perforations (16, 16', 16"), slowly impinges on the powdered product (C), and permeates the container (18), resulting in a beverage (B).

[0074] The embodiment of the filtration device (10a, 10b) of Figures 8 and 9 advantageously facilitates the removal of the powdered product (C) and the disposable paper filter (25) after the beverage (B) has been obtained. Indeed, the user simply holds the filtration device (10a, 10b) over a suitable container for disposal and removes the tubular body (11) from the support (12). In doing so, the filter (25) is no longer held in place by the retaining means, and the weight of the powdered product (C), wet from the beverage extraction, is sufficient for the filter (25) and the powdered product (C) on it to fall by gravity.

[0075] In the experiment, a beverage (B) was obtained using approximately 12 grams of powdered product (C) (specifically, coffee powder) and 300 ml of liquid (W) (specifically, boiling water) for approximately 3 minutes and 30 seconds. Furthermore, as previously mentioned, the filtration devices (10, 10a, 10b) advantageously allow for the use of a smaller amount of powdered product (C) to achieve the same TDS as conventional filtration systems.

[0076] This time is much longer than the short time required for a beverage to be produced in conventional filtration systems, with or without a cylinder and plunger, and the resulting beverage (B) has much better organoleptic properties than those obtained in such known systems. Furthermore, the present filtration device advantageously avoids bypass and channeling phenomena, which in known systems can lead to the formation of preferential liquid passages that can impair the uniformity of extraction and therefore the quality of the beverage. Furthermore, the filtration devices (10, 10a, 10b) are easy to use and require less user operating skill than those required in known systems.

[0077] Example 1 Table 1 below shows an example of how the filtration devices (10a, 10b, 10c) were used. Seven extractions were performed compared to three extractions using the conventional V60 filtration system.

[0078] As can be seen from these data, with the same recipe and particle size distribution, and therefore the same extraction surface area, the extraction efficiency of the present filtration device is higher than that of a conventional filter such as a V60. Table 1: JPEG0003253483000002.jpg20597

[0079] The results shown in Table 1 are due in particular to the absence of bypass or channeling phenomena in the filtration device, i.e., the absence of preferential channels (paths of least hydraulic resistance) for water that would tend not to extract the coffee. This is achieved in particular by the separation between the supply chamber (14), the tubular body (11) and the container (18) and by the geometry of the filtration device, in which the chamber (14) is annular and arranged around the tubular body (11). The chamber (14) is fluidly connected to the tubular body (11) by a number of through-holes (16, 16', 16"), which allow the liquid (W) to pass uniformly by gravity from the chamber (14) to the tubular body (11) and thus to the powdered product (C).

[0080] Furthermore, if the through holes (16") provide a tangential component as in Figure 7, the vortex motion of the liquid caused by this arrangement of holes (16") allows agitation of the powder product (C). Agitation by conventional methods depends on the dexterity of the operator, which may result in the extraction of undesired substances.

[0081] The filtering device also makes it possible to avoid the phenomenon of perforation of the powdered product (C), which can occur with conventional water injection techniques, since the powdered product (C) is usually placed in a compact assembly when placed in the filter.

[0082] Furthermore, to reduce the extraction yield with the same particle size distribution, it is sufficient to reduce the amount of coffee or increase the amount of water, i.e., to change the ratio of the amount of coffee to the amount of water.

[0083] The same cannot be achieved with conventional filters due to bypassing and channeling phenomena. Indeed, in V60 case 3, the particle size distribution was modified to make the particle size finer and therefore increase the extraction surface. However, despite the larger extraction surface and longer extraction time (4 minutes), the extraction yield did not increase significantly due to bypassing and channeling phenomena.

[0084] Due to its design, the filtration device allows the user to obtain an ideal extraction yield (17-27%) using less coffee or more water than conventional methods. This translates into savings for the user. For example, see extraction number 7 in Table 1.

[0085] Additionally, this preparation does not require the typical pour-and-prepare techniques of conventional methods, which require trained personnel and continuous presence during extraction.

[0086] This does not happen when using the present filtration device, and while conventional filtration devices are short in time and do not allow substances to be extracted from the coffee in a proper manner due to the presence of bypassing and channeling phenomena, the present filtration device allows for controlled extraction in a time that is suitable for wetting the entire coffee particle and extracting the substances.

[0087] Example 2 The results of further extractions with different coffee types and a coarser grind (Grade 4) are shown in Table 2 below.

[0088] The following data are from six infusions performed using the present filtration devices (10a, 10b, 10c) with the same particle size distribution, weight, and coffee used to demonstrate the reproducibility and stability of extraction facilitated by the geometry. Table 2: JPEG0003253483000003.jpg21786

[0089] It will be apparent that modifications and / or additions of parts may be made to the filtering device for brewing beverages described hereinabove without departing from the field and scope of the present invention as defined in the claims.

[0090] Although the invention has been described with reference to some particular examples, it is clear to those skilled in the art that other equivalent forms of filtering devices for extracting beverages can be realized which have the characteristics defined in the claims and which therefore all fall within the field of protection defined in the claims.

[0091] In the following claims, the sole purpose of the references in parentheses is to improve their readability; they shall not be considered as limiting factors with regard to the field of protection defined in the claims themselves.

Claims

1. A filtering device (10, 10a, 10b) for extracting a beverage (B), comprising a support (12) for accommodating a tubular body (11) and a filter (13, 25) in which a powdered product (C) is placed, and providing a chamber (14) for accommodating a liquid (W) outside the tubular body (11), the chamber (14) having a bottom (15) arranged at a position higher than the height of the filter (13, 25) and being fluidly connected to the tubular body (11) by a plurality of through holes (16, 16', 16"), so that the liquid (W) can pass by gravity from the chamber (14) to the tubular body (11) and thus to the powdered product (C), characterized in that the chamber (14) is also annular and arranged around the tubular body (11).

2. 2. A filtering device (10, 10a, 10b) according to claim 1, characterized in that the chambers (14) are arranged concentrically around the tubular body (11).

3. Filtration device (10, 10a, 10b) according to any one of the preceding claims, characterized in that the chamber (14) has the shape of a truncated cone whose cross section decreases from the upper opening (24) towards the bottom (15).

4. 10. A filtration device (10, 10a, 10b) according to any one of the preceding claims, characterized in that the bottom (15) slopes downwards towards the tubular body (11) and towards the through-holes (16, 16', 16").

5. Filtration device (10, 10a, 10b) according to any one of the preceding claims, characterized in that the through holes (16, 16', 16") are uniformly distributed on the tubular body (11) and have a radially oriented or tangential component.

6. Filtration device (10, 10a, 10b) according to any one of the preceding claims, characterized in that the through holes (16, 16', 16") are inclined downwards towards the inside of the tubular body (11).

7. Filtration device (10, 10a, 10b) according to any one of the preceding claims, characterized in that the through-holes (16, 16', 16") are arranged near the bottom of the chamber (14).

8. Filtration device (10, 10a, 10b) according to any one of the preceding claims, characterized in that the through-holes (16) are cylindrical in shape.

9. The filtration device (10, 10a, 10b) according to any one of claims 1 to 7, characterized in that the shape of the through hole (16') is a truncated cone, with a larger cross section on the inlet side of the liquid (W) and a smaller cross section on the outlet side.

10. Filtration device (10, 10a, 10b) according to any one of the preceding claims, characterized in that said tubular body (11) can be screwed onto said support (12) to be integral with said chamber (14).

11. Filtration device (10, 10a, 10b) according to any one of the preceding claims, characterized in that means (30, 32) for holding the filter (25) in place are arranged between the tubular body (11) and the support (12).

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