Abstract:
A separating device for separating a multiphase medium includes a cyclone separating device ( 1 ) that provokes an at least partial distribution of at least two phases of the medium with the formation of a vortex flow for the medium. Each phase having a lower density compared to the other phase is separated from the other phase and can be guided out of the separating device by a collecting device ( 35, 37 ).

Description:
FIELD OF THE INVENTION 
     The invention relates to a separating device for separating a multiphase medium, comprising a cyclone separating device that causes an at least partial distribution of at least two phases of this medium with the formation of a vortex flow for the medium. 
     BACKGROUND OF THE INVENTION 
     Separating devices are prior art, see, for example, U.S. Pat. No. 6,129,775. These devices are used, for example, for separating media that in a liquid phase contain a second liquid phase (for example, aqueous phase/hydrocarbon phase) or a gaseous phase or suspended solids, or for media that in a gaseous phase contain a second gaseous phase and/or a liquid phase (for example, aqueous phase) and/or suspended solids. 
     SUMMARY OF THE INVENTION 
     An object of the invention is to provide an improved separating device characterized by especially favorable operating behavior when used to separate media with phases of different density. 
     This object is basically achieved according to the invention by a separating device where one phase, having a lower density than the other phase, is separated from this other phase and can be routed out of the separating device by a collecting device. Separation of the lighter phase from a liquid or gaseous phase especially advantageously allows hydrocarbon portions (oil) or gaseous components to be separated from an aqueous phase or media with gaseous phases to be separated into gases of different density. 
     In especially advantageous exemplary embodiments, the collecting device for the lower density phase has at least one discharge pipe that, with at least one collection opening, discharges in the cyclone separating device in a zone in which the lower density phase is separated by the vortex flow. Placing the mouth of a discharge pipe of the collecting device in a zone in which separation of the lighter phase is effected by the flow, which is both centrifugally active and which also extends axially, yields a suction action within the discharge pipe. In the simplest construction, the collecting device then forms a suction device for the lighter phase so that an especially simple structure can be implemented for the entire device. 
     The suctioning-off of the lighter phase is made especially efficient when a widening increases the inlet cross section of the collection opening at the end of the respective discharge pipe. 
     The widening can be especially advantageously formed by a conical intake funnel. 
     The outer edge of the intake funnel can project radially above the wall of the discharge pipe. 
     Alternatively, the intake funnel can be formed within the wall thickness of the discharge pipe, which in this case has a correspondingly larger sufficient wall thickness. For an intake funnel integrated into the discharge pipe in this way, the advantage arises that the flow running upward on the outside of the pipe cannot be hampered by a funnel projecting above the outside of the pipe. 
     For a funnel integrated into the pipe wall, in the wall of the discharge pipe openings can be formed that lead into the interior of the intake funnel. Additional inlet cross sections for the lighter phase to be exhausted are then formed. 
     To produce a coalescing effect in the flow running along the outside of the discharge pipe, contouring can be on the outside of the wall of the discharge pipe. For this purpose, grooves or ribs can extend in the longitudinal direction or in helical lines. With respect to the coalescing action, contouring by bristles located on the outside of the pipe has proven especially effective, for example, by a round brush or spiral brush forming the contouring. Alternatively, an oleophobic coating can be on the outside of the pipe. 
     In especially advantageous exemplary embodiments, the cyclone separating device has a cyclone housing that defines a longitudinal axis with a housing inlet for inflow of the multiphase medium into a cyclone dome and has a space that adjoins the dome along the longitudinal axis and that has the collecting device for the lower density phase and housing outlets for other phases. The discharge pipe extends in the middle along the longitudinal axis within the space. 
     Especially advantageously, proceeding from the cyclone dome, a flow body can extend along the longitudinal axis as far as the end region of the discharge pipe. Here, the end of the flow body facing the discharge pipe can have the shape of a cylindrical body, for example, with a diameter similar to or equal to the diameter of the discharge pipe. This cylindrical body stabilizes the flow of the lighter phase. 
     On the end of this cylindrical body, a wedge-wire screen or a metal fabric can extend into the funnel-like widening of the discharge pipe to develop an additional coalescing action for the lighter phase. 
     Other objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses preferred embodiments of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Referring to the drawings that form a part of this disclosure: 
         FIG. 1  is a side view in section of a cyclone separating device according to a first exemplary embodiment of a separating device according to the invention; 
         FIG. 2  is a partial side view in section of only the middle longitudinal section of a cyclone separating device, which partial section is shown broken away and enlarged relative to  FIG. 1 , according to a second exemplary embodiment of the invention; 
         FIG. 3  is an enlarged partial side view in section of a central section of a cyclone housing according to a third exemplary embodiment of the invention; 
         FIG. 4  is a partial side view in section of a middle longitudinal section of a cyclone separating device according to a fourth exemplary embodiment of the invention; 
         FIG. 5  is a partial end view in section take along line V-V of  FIG. 4 ; and 
         FIG. 6  is a partial side view in section of a middle longitudinal section of a cyclone separating device according to a fifth exemplary embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In  FIG. 1 , a cyclone separating device has its cyclone housing  3  extending vertically, with respect to a longitudinal axis  4  and having an elongated shape. The cyclone housing  3  is closed on the top end  5  and on the bottom end  7 . The top end  5  forms a cyclone dome  9  into whose drum-like interior a multiphase medium can flow via a housing inlet  11  for phase separation. In the manner that is conventional for cyclone separators, the housing inlet  11  is arranged such that the medium flows in tangentially with respect to the wall of the cyclone dome  9  to form a vortex flow. The cylindrical cyclone dome  9  adjoins a cone part  13  with walls that converge downward, in which the vortex flow, with a flow velocity that is altered according to geometrical conditions, continues into an elongated cylindrical intermediate part  15 . Cone part  13  is tapered relative to the cyclone dome  9 . The lower end  17  of intermediate part  15  is in turn adjoined by a cone part  19  with walls that diverge downward and merge into a cylindrical bottom chamber  21  whose diameter corresponds to that of the cyclone dome  9 . Chamber  21  is closed on the bottom end  7 . The diameter of the cyclone dome  9  can be larger. 
     From the top end  5 , proceeding from the cyclone dome  9 , a flow body  23  extends downward in the form of a body of revolution that is coaxial to the longitudinal axis  4 . In the example shown in  FIG. 1 , the flow body  23  in its free end region forms a guide body  25  in the form of a cone extending within the cone part  13 . The cone conicity is chosen such that the transition site between the cone part  13  and the housing part  15  has a certain cross-sectional narrowing, as a result of which the flow velocity of the partial flow entering the cylindrical part  15  is uniformly accelerated up to the end of the cone and the centrifugal flow is directed. The centrifugal action of the axial flow causes separation of the phase that is “lighter” at the time within the cylindrical housing part  15 . 
     In the zone of separation of the “lighter” phase, which zone is located within the cylindrical housing part  15 , the collecting device for delivery of this phase is detailed below. For the discharge of the conversely “heavier” phases from the bottom chamber  21 , on its bottom is a housing outlet  27  with a pipe socket  29  that projects into the bottom chamber  21  and that is coaxial to the axis  4 . From the end of pipe socket  29 , filter cartridge-like, conical wedge-wire pipe screen filter element  31  extends beyond the cone part  19  into the cylindrical housing part  15 . When the flow passes through the filter element  31 , which flow passes through filter element  31  from the outside to the inside, the solids are separated from the remaining denser liquid or gaseous phase so that solid-free liquid or solid-free gas emerges from the housing outlet  27 . Solids that have been deposited on the outside of the filter element  31  and that sink or drop into the bottom chamber  21  are intermittently exhausted via another housing outlet  33 . As  FIG. 1  shows, this housing outlet  33  forms a discharge point that extends tangentially to the wall of the bottom chamber  21 , similarly to the tangential entry point of the housing inlet  11  on the top end  5 , but the discharge point at the housing outlet  33  works in the opposite direction relative thereto. Instead of a wedge-wire pipe screen filter element  31 , a mesh fabric or the like can be provided. 
     The collecting device for the separated, respective “lighter” phase has a discharge pipe  35 . Discharge pipe  35  extends from the outside of the cyclone housing  3  through the housing outlet  27  of the bottom chamber  21 , through the pipe socket  29  and the inner filter cavity of the filter element  31 , which cavity is fluid-connected to the pipe socket, and into the middle along the longitudinal axis  4  as far as the central region of the cylindrical housing part  15  where the zone of the separated “lighter” phase is located. The open end of the discharge pipe  35  forms the collection opening  37  for the outflow of the separated phase. For the geometry of the cyclone housing  3  shown in  FIG. 1 , where the vortex flow in the cylindrical housing part  15  moves axially downward until flow reversal takes place, and where a secondary flow that rises along the outside of the discharge pipe  35  arises, a strong negative pressure prevails in the separation zone. That is, in the region of the collection opening  37  of the discharge pipe  35  and in the center of the vortex flow, as a result of which a strong suction action forms in the discharge pipe  35 . At an axial velocity of from about 0.1 m/s to 0.4 m/s that is pointed downward in operation above the collection opening  37  in the cylindrical housing part  15  and for a secondary flow that rises along the discharge pipe  35  with an axial velocity of about 1 m/s, a flow velocity within the discharge pipe  35  downward can be established in the range of about 10 m/s. The discharge pipe  35  then forms an effective exhaust apparatus for the lighter phase. In practical exemplary embodiments, the inside diameter of the discharge pipe  35  can be about 4 mm, with an inside diameter of the cylindrical housing part  15  of about 65 mm. This rising secondary flow is preferably formed from components of the light phase. 
       FIG. 2  shows an exemplary embodiment that is modified relative to and that differs from  FIG. 1  in that the flow body  23 , instead of a shorter, end-side cone part  25 , has an elongated cylindrical flow guide body  39 . Moreover, on the end of the discharge pipe  35  is a widening that enlarges the inlet cross section of the collection opening  37  and that is formed by a conical intake funnel  41 . The funnel  41  in the example of  FIG. 2  is dimensioned such that the diameter on the outer funnel edge  43  that projects radially above the discharge pipe  35  is about six times the inside diameter of the discharge pipe  35 . This execution ensures especially effective exhaust of the separated lower density phase. 
       FIG. 3  illustrates one version of the configuration of the discharge pipe  35  and its intake funnel  41 . Instead of a fitted funnel with an edge that projects radially above the outside of the discharge pipe  35 , the funnel  41  is integrated into the pipe wall  45  of the discharge pipe  35 , which is made correspondingly thick-walled in this case. In this exemplary embodiment, in addition to the advantage of the inlet cross section of the discharge pipe  35 , which cross section has been widened in the form of a funnel, the further advantage is provided that no radially projecting funnel edge  43  is present around which the secondary flow that flows upward along the outside of the discharge pipe  35  must flow. As is shown in  FIG. 3 , in the pipe wall  45  of the discharge pipe  35 , radial bores  47  are formed that lead into the interior of the funnel  41 , and thus, further enlarge the inlet cross section for the flow into the interior of the discharge pipe  35 . This funnel  41  can also be made from a metal fabric. 
     The outside of the discharge pipe  35  can be used to have a coalescing action on the secondary flow that is rising on it. For this purpose, the outside of the discharge pipe  35  can be provided with contouring or with an oleophobic coating for coalescing of oil, for example.  FIGS. 4 and 5  illustrate an example in which for this purpose bristles of a brush body  49  surround the discharge pipe  35 . The brush body  49  can be formed in this connection by a brush roll, by individual round brushes or spiral brushes. As suggested in  FIG. 5  with oil droplets  51 , coalescing takes place when the brush penetrates from the outside to the inside, and the outflow can take place within the gusset  53  (not all numbered). 
     Instead of contouring by the brush body  49  on the outside of the discharge pipe  35 , grooves, ribs, or the like can be used. 
       FIG. 6  shows another example similar to the example of  FIG. 2 , aside from the fact that the free end of the flow guide body  39  is adjoined by a wedge-wire screen  55  that extends into the interior of the funnel  41 . At a fineness of, for example, 500 μm, the screen  55  forms an additional coalescing zone within the exhaust zone for the phases of the respective lower density. All flows within the housing of the device move along a vortex flow that points in the same direction. In particular, the lighter phase, which rises up opposite the other vortex flow within the housing of the device along the discharge pipe  35 , has the same vortex direction so that no interference superpositions occur within the fluid flow. 
     While various embodiments have been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.