DEVICE FOR TREATING FLUID MIXTURES

Abstract

The invention relates to a device for treating fluid mixtures, which contain gases, such as in particular hydrogen (H2), air, nitrogen (N2), or natural gases, and liquids, such as in particular ionic liquids, hydraulic fluid, or process liquids, comprising at least a first separation stage (29) for separating the fluid mixture into a liquid fraction and a gas fraction, which is contaminated with a remaining liquid fraction, from which gas fraction said remaining liquid fraction is removed in at least one further separation stage (67).

Claims

1. A device for treating fluid mixtures that contain gases, such as in particular hydrogen (H.sub.2), air, nitrogen (N.sub.2), or natural gases, and liquids, such as in particular ionic liquids, hydraulic fluid, or process liquids, with a least a first separation stage (29) for separating the fluid mixture into a liquid fraction and into a gas fraction, which is contaminated with a remaining liquid fraction, from which gas fraction this remaining liquid fraction is removed in at least one additional separation stage (67).

2. The device according to claim 1, characterized in that a centrifugal separator (29) is provided as a first separation stage.

3. The device according to claim 1, characterized in that a coalescing filter (67) is provided as a second separation stage.

4. The device according to claim 1, characterized in that all separation stages (29, 67) are arranged in a common housing (1), which has an inlet (5) for the fluid mixture, an outlet (37) for the gas fraction separated from the liquid, and at least one emptying outlet (19, 39) for removing the cleaned liquid.

5. The device according to claim 1, characterized in that the housing (1) has a cavity extending along a vertical axis (3), in which the centrifugal separator (29) is arranged between the overlying coalescing filter (67) and an underlying collection space (15) for receiving separated liquid.

6. The device according to claim 1, characterized in that the interior wall (43) of the cyclone housing (31) of the centrifugal separator (29), on the lower end thereof that borders the collection space (15), delimits a ring opening (45) between a pipe section (47) concentric to the axis (3), which opening forms a connection between the area of the cyclone cylinder (31) distal to the axis and the collection space (15).

7. The device according to claim 1, characterized in that the interior space (53) of the pipe section (47) forms part of a connection between the area of the cyclone cylinder (31) proximal to the axis and the upper area of the collection space (15).

8. The device according to claim 1, characterized in that the coalescing filter (67) has a filter material (73) surrounding an interior filter cavity (77) and that a connection channel (61) is provided between the upper area of the collection space (15) and the filter cavity (77) of the coalescing filter (67).

9. The device according to claim 1, characterized in that the coalescing filter (67) has a coaxial interior pipe (79), which opens at its upper end (81) into the space (9) of the housing (1) bordering the outside of the filter material (73) and which leads at its lower end to the housing outlet (37) for the gas fraction.

10. The device according to claim 1, characterized in that a demister (65) is provided as a third separation stage between the upper end of the collection space (15) and the connection channel (61) leading to the interior filter cavity (77) of the coalescing filter 67).

11. The device according to claim 1, characterized in that a particle filter (21) is provided between the floor area of the collection space (15) and an emptying outlet (19).

Description

[0025] With reference to the drawings, the invention is explained with the example of a device that is provided for separating liquid fractions from a fluid stream of a fluid mixture under a pressure of 700 bar to 1000 bar. The fluid mixture predominantly has hydrogen gas with fractions of an ionic liquid. Any solid particles that may be present in the fluid mixture can also be separated from the gas by means of the device. The device shown can obviously be used for treating other media mixtures that contain, in a gas, liquid fractions that need to be separated and possibly solid particles that need to be separated.

[0026] The illustrated exemplary embodiment of the device has a longitudinally extended housing 1, which as a whole possesses the shape of a circular hollow cylinder, the axis 3 of which runs vertically in the installed position of the device. The housing 1 has an upper housing part 5 that delimits a coalescing filter chamber 9 with its rounded end piece 7. The lower open end of the upper housing part 5 is screwed tightly to an intermediate part 11, which forms the transition to a lower housing part 13, which prolongs the circular cylindrical outer contour of the upper housing part 5 and which delimits an interior collection space 15 that is closed on its lower end by a tightly screwed-in floor part 17. Located in the floor part 17 is an emptying outlet 19 with an upstream particle filter 21, via which the liquid located in the collection space 15 can be drained from the floor area of the collection space 15.

[0027] The intermediate part 11 has the form of a rotation body that forms, subsequently to its being screwed by its threaded section 23 to the upper housing part 5, a radially projecting flange 25 to which in turn a lower threaded section 27 connects, on which the tight screw connection to the lower housing part 13 is formed. On the upper side and on the lower side, the flange 25 thus forms the respective contact surface for the end edge of the upper housing part 5 and for the end edge of the lower housing part 13, respectively. The centrifugal separator 29 that forms the first separation stage with the circular cylindrical cyclone housing 31 concentric to the axis 3 is located in the intermediate part 11, an inflow opening 33 opening at the upper end of said housing. Via this opening, the fluid mixture can flow tangentially from a fluid inlet 35 formed in the flange 25 into the cyclone housing 31 such that a swirl flow or a cyclone is formed in the cyclone housing 31, in the manner typical of cyclone separators 29. In addition, an outlet 37 for draining off the gas fraction separated from the fluid mixture, a liquid outlet 39 arranged offset by 90° in relation to the inlet 35 and the outlet 37 (see FIGS. 2 and 5), and channels forming fluid connections are located in the intermediate part 11.

[0028] As is most clearly discernible in FIG. 4, a sleeve 41, which is inserted into the intermediate part 11 and which extends axially beyond the lower end of the intermediate part 11 in the direction of the collection space 15, forms the end section of the interior wall 43 of the cyclone housing 31. On the lower end of the sleeve 41, the interior wall 43 delimits a ring opening 45 between a pipe section 47, which extends concentrically to the axis 3 into the sleeve 41 and out into the collection space 15 via its lower end. In this arrangement, the ring opening 45 forms the connection between the lower area of the cyclone housing 31 distal to the axis and the collection space 15, in other words the outlet opening via which droplets that have been deposited, as the more dense mixture component of the fluid mixture, on the interior wall 43 under the effect of centrifugal force.

[0029] A carrier rod 49 anchored at the upper end of the cyclone housing 31, specifically in the intermediate part 11 near 48, extends coaxially through the cyclone housing 31 and out of it via the lower end of the pipe section 47. By means of a pin 51 seated in the lower end 50 of the carrier rod 49, a cover part 52 is mounted on the carrier rod 49, to which the lower end of the pipe section 47 is in turn screwed such that the carrier rod 49 forms the carrier element for the pipe section 47, which surrounds the carrier rod 49 at a distance. The interior space 53 of the pipe section 47 thus forms a connection between the area of the cyclone housing 31 proximal to the axis and a gas outlet nozzle 55, which opens inside the cover part 52 into the interior space 53 of the pipe section 47. The gas fraction located in the area of the cyclone housing 31 proximal to the axis thus exits via the outlet nozzle 55 into the upper area of the collection space 15.

[0030] A funnel-like recess 59 is located in the end surface of the intermediate part 11 facing the collection space 15, within the end edge 57 thereof. Starting from this recess, a connection channel 61 extends to the upper end surface of the intermediate part 11, as can be best discerned in FIG. 5. A demister 65, which surrounds the end of the sleeve 41 projecting from the recess 59, is arranged in a manner known per se between the end edge 57 and a ledge 63 on the interior wall of the lower housing part 13. The gas fraction exiting the pipe nozzle 55 and other gas fractions that are at least partially impregnated with liquid and that surround the pipe section 47, on the outer circumference thereof, therefore pass through the demister 65 prior to entering the recess 59, before the respective gas fraction further freed of liquid flows in upward movement along the flow path through the connection channel 61 to the upper side of the intermediate part 11.

[0031] The coalescing filter 67 that forms the second separation stage is arranged on the upper side of the intermediate part 11 that forms the lower end of the coalescing filter chamber 9. This filter has a foot part 69 that connects to the upper side of the intermediate part 11 and that forms a seat for a lower end part 71, from which the filter material 73 extends to the upper end part 75 of the coalescing filter 67. Within the filter cavity 77 surrounded by the filter material 63, an interior pipe 79 extends coaxially through the entire coalescing filter 67, wherein the interior pipe 79 is open at its upper end 81 passing through the end part 75 and is thus in communication with the space of the filter chamber 9. The other, lower end of the interior pipe 79, which extends into the intermediate part 11, is connected to the outlet 37 for the gas fraction via an oblique channel 83, as FIGS. 1 and 4 show.

[0032] As indicated with flow arrows in FIG. 5, the gas exiting from the pipe nozzle 55 in the upper area of the collection space 15, which after having passed through the centrifugal separator 29 has only a reduced liquid fraction, passes through the demister 65 and, via the connection channel 61, an adjoining passage 85 in the foot part 69 and also an opening 87 in the lower end part 71 of the coalescing filter 67, reaches the interior filter cavity 77 thereof, where it flows from inside to outside through the filter material 73 thereof, which forms the second separation stage. In this process, remaining liquid fractions are deposited on the outside of the filter material 73, from where they migrate downward within the filter chamber 9 and, from the floor of the filter chamber 9, reach the liquid outlet 39 via a vertical channel 89.

[0033] The gas, which reaches the surrounding filter chamber 9 from the interior filter cavity 77 after having flowed through the filter material 73, is free of liquid fractions after having passed through the cyclone separator 29, after having passed through the demister 65, and after having passed through the coalescing filter 67. Owing to the fact that they are denser than hydrogen, liquids as well as solid particles can be separated from the hydrogen by means of the cyclone separator 29. The demister 65 interposed in the separation process enables droplets larger than 5 μm to be separated from the gas flow of the fluid mixture so that the downstream coalescing filter 67 is used exclusively for treating the finest droplets smaller than 5 μm. The demister 65 is therefore disposed upstream of the coalescing filter 67 as a third separation stage for a particularly effective fine separation. From the filter chamber 9 and as indicated by the curved arrow 91 in FIG. 5, the gas enters the interior pipe 79 via the upper end 81 and from there it reaches the outlet 37 of the gas side via the oblique channel 83. With the routing of the flow via the axial interior pipe 79, the hazard of liquid droplets (which are located on the outside of the filter material 73 in the filter chamber 9) being entrained to the gas outlet 37 is thus avoided.

[0034] In the illustrated exemplary embodiment, the collection space 15 for receiving a supply of separated liquid that drained into the collection space via the ring opening 45 of the cyclone housing 31, is configured such that a volume of 5 liters, for example, can be received in the collection space 15 within the lower housing part 13. As shown in FIG. 1, provision can be made of a control mechanism in the form of a fill level indicator for controlling emptying processes taking place via the outlet 19. In this example, provision to this effect is made of a floating body 93, which is guided on a guide 95 that forms the measuring section for a position sensor system 97. This can be a non-contact sensor mechanism, for example a magnetostrictive process in which a waveguide is tensioned within the guide 95.

[0035] In summary, it can be concluded that the concrete exemplary embodiment of the device according to the invention is used to treat a gas flow, for example hydrogen under high pressure that is only slightly contaminated with liquids, for example ionic fluids on an order of up to 5% maximum.

[0036] For the separation to this effect, the device solution according to the invention employs three different separator stages that are used for separating out contaminants in both liquid and particulate form. In the sequence of the treatment process, these would be: [0037] 1. Centrifugal separator, which enables a separation of higher density particles and liquids, [0038] 2. Demister, which enables a separation of larger droplets, specifically larger than 5 μm, and accordingly prevents liquid from penetrating the coalescing filter element, and [0039] 3. Coalescing filter element, which is used for separating the finest aerosols, preferably with a droplet size of <5 μm

[0040] In addition to minimizing liquid carry-over, the removal of the filtered gas from the collection space 9 through the coaxially arranged drainage line 79 offers a further advantage for the device that the pressure vessel or rather the filter housing of the coalescing filter can be configured as two parts (components 5 and 11), wherein all supply and drainage lines can be housed in a fixed part 11 of the device. Because it is not necessary to disconnect any lines and the housing head permits “convenient” access to the element to be changed, changing or replacing elements is enormously simplified. The housing would otherwise have to be constructed in three parts, which is less maintenance friendly and associated with additional costs.