Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D45/00—Separating dispersed particles from gases or vapours by gravity, inertia, or centrifugal forces
  • B01D45/12—Separating dispersed particles from gases or vapours by gravity, inertia, or centrifugal forces by centrifugal forces
  • B01D45/14—Separating dispersed particles from gases or vapours by gravity, inertia, or centrifugal forces by centrifugal forces generated by rotating vanes, discs, drums or brushes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D45/00—Separating dispersed particles from gases or vapours by gravity, inertia, or centrifugal forces
  • B01D45/12—Separating dispersed particles from gases or vapours by gravity, inertia, or centrifugal forces by centrifugal forces
  • B01D45/16—Separating dispersed particles from gases or vapours by gravity, inertia, or centrifugal forces by centrifugal forces generated by the winding course of the gas stream, the centrifugal forces being generated solely or partly by mechanical means, e.g. fixed swirl vanes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
  • B04C—APPARATUS USING FREE VORTEX FLOW, e.g. CYCLONES
  • B04C3/00—Apparatus in which the axial direction of the vortex flow following a screw-thread type line remains unchanged ; Devices in which one of the two discharge ducts returns centrally through the vortex chamber, a reverse-flow vortex being prevented by bulkheads in the central discharge duct
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
  • B04C—APPARATUS USING FREE VORTEX FLOW, e.g. CYCLONES
  • B04C3/00—Apparatus in which the axial direction of the vortex flow following a screw-thread type line remains unchanged ; Devices in which one of the two discharge ducts returns centrally through the vortex chamber, a reverse-flow vortex being prevented by bulkheads in the central discharge duct
  • B04C3/06—Construction of inlets or outlets to the vortex chamber
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21C—NUCLEAR REACTORS
  • G21C15/00—Cooling arrangements within the pressure vessel containing the core; Selection of specific coolants
  • G21C15/16—Cooling arrangements within the pressure vessel containing the core; Selection of specific coolants comprising means for separating liquid and steam
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E30/00—Energy generation of nuclear origin
  • Y02E30/30—Nuclear fission reactors

Definitions

• the present invention relates to a separator for separating liquid from a mixture of gas and liquid.
• the separator is especially suited for separation of water from a steam/water mixture in water-cooled nuclear reactor.
• the separation of water takes place for the purpose of conducting, as far as possible, steam only to subsequent turbines for the production of electric power.
• a plurality of similar separators are arranged for separating the water and carrying away the water to a suitable receiving member.
• SE 373 451 shows (see Figure 1 in the present application) a separator 1 which, divided into parts, exhibits a lower part a, a middle part b and an upper part c.
• the lower part comprises a blade device 2 for achieving rotation of an incoming two-phase mixture adapted to flow upwards through the separator 1.
• a liquid film is achieved along the inner wall of the separator 1, above all in the middle part b of the separator.
• an expulsion pressure is achieved which is necessary for evacuating separated liquid through a primary discharge.
• an outlet member for the primary- discharge is arranged, that is, evacuation of the substantial part of the liquid separated from the mixture.
• the middle part b is designed as an elongated pipe with a narrow circular-cylindrical part and a part which is tapering in the direction of flow, constituting a conical part with a substantially circular cross section.
• the middle part b is provided, in the conical part, with a plurality of outlet members in the form of openings 3 constituting the member for evacuation of the separated liquid to the outside of the middle part b.
• the upper part c is arranged for carrying away the remaining mixture, that is, the gas.
• the upper part c is designed as a pipe with an upstream, substantially straight circular- cylindrical part and a downstream part which is extended in the direction of flow.
• the circular-cylindrical part of the upper part is partially arranged inserted into the middle part b with a length which is larger than the extent of the conical part.
• the upper part c is coaxially arranged in relation to the middle part b.
• An outer, substantially circular-cylindrical casing 4 is arranged surrounding the lower part a, the middle part b and the upper part c so as to form an annular gap 5 between the casing 4 and the separator 1.
• the gap 5 constitutes a return passage for liquid which has been evacuated through the openings 3 in the middle part b.
• SE 502 765 shows (see Figure 2 in the present application) a separator 1 of the same type as the one described above, but here the middle part b is provided with openings 3 both in the conical and in the circular-cylindrical part.
• the openings 3 are arranged also in the circular-cylindrical part to allow a larger opening cross section than what is possible to achieve in practice in the conical part.
• the disadvantage of the separators described above is that the expulsion pressure which causes the liquid to be evacuated through the openings is lower the higher up in the conical part the openings are provided.
• the fact that the expulsion pressure becomes lower in the conical part than in the circular-cylindrical part is due to isobaric surfaces prevailing in the liquid film where the pressure is constant.
• the pressure distribution in the liquid film is such that the pressure increases with the distance from the centre of the separator. The pressure is thus greatest in that isobaric surface which is arranged nearest the wall of the separator.
• a further disadvantage of the known separators is that the openings in the conical part alone and together with the inlet opening into the upper part limit the operating range of the separator by limiting the space for the liquid film.
• the thickness of the liquid film is a function of the magnitude of the gas and liquid flows which pass through the separator.
• the liquid film, formed because of the rotation, along the inner wall of the separator may receive a consider- able thickness, in which case the inner surface of the liquid film may touch the inlet opening into the upper part of the separator.
• the proportion of liquid leaving the separator together with the gas increases dramatically.
• a concept which describes the proportion of liquid leaving the separator together with the gas is the so- called carry-over value. In the design of a separator, it is an aim to maintain the carry-over value as low as possible.
• the present invention relates to a separator which, in relation to known separators, has an improved capacity of separating the liquid.
• the present invention relates to a separator for separating liquid from a mixture comprising gas and liquid.
• the separator comprises an elongated pipe which is open at both ends and which is divided into a first, lower part, a second, middle part, and a third, upper part.
• the lower part comprises an inlet for the mixture and members for achieving rotation in the mixture and an outlet for the rotating mixture. The rotation is achieved with a conventional blade device.
• the middle part is provided with an inlet for the rotating mixture and is designed for separation of the liquid from the mixture.
• the middle part is divided into a fourth, a fifth and a sixth part.
• the fourth and sixth parts are designed with tight walls whereas the fifth part is designed with outlet members in the form of openings for evacuation of the separated liquid.
• At least the fifth part is designed as a substantially circular-cylindrical part.
• the sixth part is intended for outlet of the remaining mixture.
• the upper part is intended for inlet and outlet of the remaining mixture, that is, the gas.
• the separator with openings only in a circular-cylindrical part is that the size, the location, and the extension of the openings may be adapted to current gas and liquid flows.
• the upper part of the separator substantially constitutes a transport distance for the remaining mixture and has no primary influence on the separation capacity of the separator and may, therefore, be given an arbitrary design.
• the upper part may, for example, be straight circular-cylindrical or conical .
• An advantage of designing the whole separator pipe with a substantially straight circular-cylindrical shape is that it is considerably more simple to manufacture such a separator than the known separators since no conical part need be included, still less a conical part with openings.
• the conical part is geometrically limited, in which case it is more difficult to calculate how the openings are to be arranged in this surface in an optimum way in comparison with the arrangement of such openings in a part which is designed as a straight cylinder with a substantially circular cross section.
• the amount of liquid in the mixture remaining after the separation may be further minimized by arranging a separate upper part extending into the middle part in such a way that its inlet is arranged downstream of the evacuation openings in the middle part .
• the middle part as a substantially straight circular-cylindrical part
• the enlarged gas outflow cross section implies that the pressure drop across the separator is reduced in comparison with the known separators described under the background art.
• the operating range of the separator is suitably chosen such that it is arranged in an optimum way between the boundary curves which may be calculated for the carry-over and carry- under values, respectively. This is possible by the size and location of the openings in the circular-cylindrical part being adapted and optimized for the current gas and liquid flows .
• Figure 1 shows a separator with outlet members in the form of openings in a conical part described under the background art .
• Figure 2 shows an alternative separator with outlet members in the form of openings both in a conical part and in a circular-cylindrical part. Also this separator is described under the background art.
• Figure 3 shows in a longitudinal cross section a separator according to the invention, which comprises a substantially straight circular-cylindrical pipe which is open at both ends. Only one circular-cylindrical part is provided with outlet members in the form of openings .
• Figure 4 shows an alternative embodiment of a separator with a cross section increasing in the direction of flow.
• a dash- lined contour indicates an alternative embodiment wherein the upper part is designed with a cross section which decreases in the direction of flow.
• Figure 5 shows an embodiment of a separator according to the invention which comprises an upper part arranged inserted into a circular-cylindrical middle part where the upper part is designed with a cross section increasing in the direction of flow.
• Figure 6 shows an embodiment of a separator according to the invention which, in a middle part, comprises a conical part and an upper part arranged inserted thereinto, wherein the upper part is designed with a cross section increasing in the direction of flow.
• a dash-lined contour indicates an alterna- tive embodiment where the upper part is designed as a straight circular-cylindrical pipe.
• Figure 7 shows an embodiment of a separator according to the invention wherein a substantially circular-cylindrical casing is arranged to surround the separator and, together with this, to form an annular gap.
• Figure 8 shows, in a view from above, an embodiment wherein several groups of separators are arranged and wherein they are arranged in- groups surrounded by a casing such that each casing surrounds a plurality of separators.
• Figure 9 shows in detail an embodiment of a scraper ring shown in Figure 7.
• Figure 3 shows a separator 1 which comprises an elongated pipe which is open at both ends .
• the separator 1 is divided into a first, lower part a, a second, middle part b, and a third, upper part c.
• the lower part a comprises an inlet for a mixture of gas and liquid.
• the lower part a further comprises a blade device 2 which is adapted to set the incoming mixture in a rotary or turning motion. Through the influence of a centrifugal force in the rotating mixture, the liquid in the two-phase mixture will make contact with the inside of substantially the wall of the middle part b and will form a distinct, well coherent liquid film.
• the middle part b comprises an inlet for the rotating mixture, outlet members for evacuation of the separated liquid and an outlet for the remaining mixture.
• the middle part b is divided into a fourth part d, a fifth part c and a sixth part d.
• the fifth part e is designed for separation of the liquid from the mixture.
• the fifth part e comprises a substantially straight circular- cylindrical part which is provided with outlet members in the form of a plurality of openings 3 through which the separated liquid is evacuated.
• the wall of the fifth part e with the openings 3 is dimensioned in dependence on the type of plant, for example a- nuclear reactor, in which it is to be used. This implies, for example, that the middle part b is provided with openings 3 of a smaller total area for plants with a large gas flow and with openings 3 of a larger total area for plants with a large liquid flow.
• the fourth part d and the sixth part f are designed with tight walls for the purpose of not evacuating any separated liquid.
• the upper part c is intended for inlets and outlets of the remaining mixture, that is, the gas.
• both the upper part c and the middle part b are integrated and designed in the same pipe part, provided with a substantially straight circular-cylindrical shape.
• Figure 5 shows a separator 1 which comprises a separate upper part c which is arranged inserted into the middle part b.
• the upper part c By arranging the upper part c for outlet of the remaining mixture inserted into the middle part b, it is further ensured that the liquid flowing along the inner wall of the separator 1 is protected from the influence of the remaining mixture flow upwards through the separator. At least a part of the liquid film which is adapted to cover the openings 3 will continue to flow upwards, with the aid of the remaining mixture, along the inner wall in at least the fifth part e.
• the inlet of the upper part c is arranged at a level which is arranged downstream of the wall portion with the openings 3.
• the remaining mixture that is the gas
• the remaining mixture may be removed from the separator 1 without the liquid film, which is greatly reduced because of the primary outlet, being evacuated therewith. This implies that the liquid is prevented from remoistening the gas, which, in turn, causes the carry-over value to be further kept low.
• Figure 6 shows an embodiment of the separator 1 in Figure 5, wherein the middle part b is partially conical. More particularly, the sixth part f is conical.
• the upper part c is arranged inserted into the conical middle part b and designed with a cross section increasing in the direction of flow.
• An additional alternative embodiment of the upper part c is indicated by a dash-lined contour, more particularly an upper part c with a circular-cylindrical shape.
• Figure 7 shows an alternative embodiment of a separator 1, wherein a casing 4 is adapted to surround at least the fifth part e. Between the casing 4 and the fifth part e, an annular gap 5 is formed for return passage of the liquid separated through the openings 3.
• an outer casing 4 in this way permits a reduced risk of adjacently located separators 1 disturbing the evacuation of liquid from the separator 1 in question. It is also possible to allow the casing 4 to surround a group of a plurality of separators 1, as shown in Figure 8. In this case, the casing 4 is given a cross section with an arbitrary shape for adaptation to the group of separators 1.
• Figure 8 shows a plurality of groups, wherein each group comprises five separators 1 arranged in, for example, the upper part of a nuclear reactor 10.
• Figure 7 further shows that the upper part c of the separator
• scraper rings 6 are arranged for secondary separation of liquid which passes with the gas past the primary separation, that is, the openings 3.
• the ⁇ scraper rings 6, which are shown in more detail in Figure 9, are thus adapted to scrape off and evacuate the liquid which is separated from the mixture downstream of the openings 3.
• the scraper rings 6 are of a conventional type and adapted to reduce the amount of liquid accompanying the gas out, that is, to keep down the carryover value defined under the background art.
• Figure 3 shows a separating member 11 in the form of a truncated cone.
• the separating member 11 is arranged in the middle part b and radially inside the fifth part e.
• the separating member 11 is arranged such that it has a cross- section area increasing in the direction of flow. The difference between the inner cross-section area of the separator 1 and the outer cross-section area of the separa- ting member 11 at the upstream edge of the separating member
• the object of the separating member 11 is to achieve an additionally improved separation of the liquid by preventing the liquid film from flowing upwards along the inner wall of the separator so far that it risks becoming unstable and collapsing.
• the separating member 11 has an extent in the axial direction of the separator which substantially corresponds to the axial extent of the fifth part e.
• the downstream edge of the separating member 11 is tightly connected to the inner wall of the separator 1.
• the separating member 11 has the shape of a pipe with an arbitrary cross section.
• Figure 7 shows a separating member 12 in the form of an inner shoulder arranged downstream of the openings 3.
• the separating member 12 is adapted to extend from the inner wall of the separator 1 and radially inwards along a distance which at least corresponds to the thickness of the liquid film in this part of the separator 1.
• the object of the separating member 12 is the same as that of the separating member 11 according to Figure 3.
• the separating member 12 has a tubular part connected to the shoulder and extending in an upstream direction.
• the tubular part has an arbitrary cross section.
• middle parts b, upper parts c, casings 4, scraper rings 6 and separating members 11, 12 shown may be combined in a plurality of different ways (not shown) .

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Plasma & Fusion (AREA)
• General Engineering & Computer Science (AREA)
• High Energy & Nuclear Physics (AREA)
• Degasification And Air Bubble Elimination (AREA)
• Cyclones (AREA)
• Separating Particles In Gases By Inertia (AREA)
• Centrifugal Separators (AREA)

Applications Claiming Priority (3)

Publications (1)

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Family Applications (1)

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• 1997
  • 1997-04-15 SE SE9701386A patent/SE509685C2/sv unknown
• 1998
  • 1998-04-14 KR KR1019997009476A patent/KR20010006389A/ko not_active Application Discontinuation
  • 1998-04-14 JP JP54382298A patent/JP4151993B2/ja not_active Expired - Lifetime
  • 1998-04-14 WO PCT/SE1998/000687 patent/WO1998046328A1/en not_active Application Discontinuation
  • 1998-04-14 EP EP98917900A patent/EP0975412A1/en not_active Withdrawn

Non-Patent Citations (1)

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