Abstract:
A separator including a rotatable drum having a drum top part, a vertical axis of rotation and a disk stack arranged therein. Also included is a piston slide for opening and closing solids discharge openings in the drum. A radial gap is formed between the drum top part and the piston slide in an open condition of the piston slide. Radially successive annular chambers are located in the piston slide and in the drum top part and are mutually connected by a bottleneck.

Description:
BACKGROUND AND SUMMARY 
   The present disclosure relates to a separator having a rotatable drum with a vertical axis of rotation, in which a plate stack is arranged. The separator includes a piston slide for the opening and closing of solids discharge openings in the drum. In an opened condition of the piston slide, a radial gap is formed between the drum  2 , or a top part of the drum, and the piston slide. 
   In the case of separators of this type, which have piston slides, there is the need to reduce the occurrence of erosive phenomena in the area of the solids discharge openings, particularly evacuation slots, and to minimize the effect of the depositing of contaminations in this area. 
   Separators with piston slides are illustrated in German Patent Documents DE 38 03 762 A1, DE 102 20 757 A1, DE 44 36 459 C2 and U.S. Pat. No. 5,916,083. Separators with nozzle openings are illustrated in German Patent Document DE 195 27 039 C1 and U.S. Patent Document US 290060,239. 
   The present disclosure addresses the above-referenced needs. 
   The present disclosure relates to a separator that includes a rotatable drum having a drum top part, a vertical axis of rotation and a disk stack arranged therein. Also included is a piston slide for opening and closing solids discharge openings in the drum. A radial gap is formed between the drum top part and the piston slide in an open condition of the piston slide. Also included is at least one annular chamber located on both sides of the radial gap in front of the solids discharge openings in an outer circumference area of the piston slide and the drum top part. 
   Accordingly, as noted above, at least one annular chamber is constructed on both sides of the gap, radially in front of the solids discharge openings in the outer circumference area of the piston slide and the drum top part. 
   It may be that two radially successive annular chambers are constructed in the piston slide and in the top part of the drum. The two annular chambers are constructed symmetrically with respect to the contact surface of the piston slide on the top part of the drum in the closed condition. Specifically, this construction causes considerably optimized flow conditions in the area of the discharge openings. 
   The two annular chambers in the closed condition of the piston slide are constructed symmetrically with respect to the contact surface of the piston slide on the top part of the drum. 
   A radially interior annular chamber of the annular chambers is constructed as a fanning-out chamber for an exiting stream of solid matter. 
   A radially exterior annular chamber of the annular chambers is constructed as a swirl chamber for the exiting stream of solid matter. 
   The present disclosure relates to the flow conditions in the area in front of the solids discharge openings in a simple manner by an optimization of the geometry in the piston solid and drum elements, particularly the top part of the drum, which are connected in front of the solids discharge openings. This results in a corresponding treatment of these elements but not in additional expenditures of material. The separator of the present disclosure can be implemented in a simple manner and minimizes not only the effect of the erosive phenomena in the area of the solids discharge openings but also reduces the tendency to form deposits. The separator according to the present disclosure contributes to a high operative readiness of the separator and to a reduction of the necessity of cleaning operations, particularly if two annular chambers are provided which follow one another radially and are connected by way of a bottleneck. 
   Other aspects of the present disclosure will become apparent from the following descriptions when considered in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic, sectional view of a separator, according to the present disclosure. 
       FIG. 2  is a view of an area of a solids discharge opening on the drum of the separator of  FIG. 1  when the piston slide is open. 
       FIG. 3  is a view similar to that of  FIG. 2 , when the piston slide is closed. 
   

   DETAILED DESCRIPTION 
     FIG. 1  is a schematic sectional view of a separator  1  with a rotatable drum  2  and a one-piece or multiple-piece non-rotatable hood  3  which surrounds the drum completely or for the most part. The drum  2  has a vertical drum axis and axis of rotation M, and has an intake pipe  4  extending, for example, into the drum  2  from above. A distributor  5  is connected on an output side of the intake pipe  4 , through which distributor  5  centrifugal material is guided into the drum  2 . A disk stack  6  of a plurality of conical disks  7  is arranged in the drum  2 . 
   The removal of, for example, two liquid phases from the drum  2  takes place by two centripetal pumps or grippers  8 ,  9  to which outlet pipes  10 ,  11  are assigned. 
   For discharging solids accumulating in a solids space  12 , a piston slide  13  is used, as shown in  FIGS. 1 to 3 . Piston slide  13  can be operated, for example, pneumatically or hydraulically and opens up or closes solids discharge openings  14 . 
     FIG. 1  is an illustrated embodiment of the separator  1 . 
   According to  FIG. 2 , the solids discharge openings  14  are constructed as bores or slots in a bottom part  15  of the drum  2 , which slides discharge openings  14  extend through the bottom part  15  from an inside to an outside of the bottom part  15 . The solids discharge openings  14  are uniformly distributed on a circumference of the bottom part  15  of the drum  2 , so that webs (not shown) remain in between the solids discharge openings  14 . 
   In a closed condition of the drum  1 , the piston slide  13  rests against a top part  16  of the drum  2  at a lower edge of the top part  16  of the drum  2 . A sealing ring  17  is arranged in a groove  18  in the top part  16  of the drum  2 . In the closed condition, when the piston slide  13  is moved upward, the sealing ring  17  closes or seals off a gap  19  between adjoining surfaces  20 ,  21  of the piston slide  13  and of the top part  16  of the drum, as shown in  FIG. 3 . 
   When the piston slide  13  is open or opening, an exiting solids stream S impacts in a narrowly focused manner on points of the bottom part  15  of the drum, for example, on edges of the solids discharge openings  14 . This leads to erosive phenomena and deposits in the gaps between these elements, mainly in an axial gap between the piston slide  13  and the bottom part  15  of the drum  2  and between the top part  16  of the drum  2  and the bottom part  15  of the drum  2 . 
     FIG. 2  illustrates the open condition of the piston slide  13 , in which the gap  19  is formed, and  FIG. 3  shows the closed condition of piston slide  13 . A width of gap  19  may slightly vary in practice from one opening operation to the next. The following conditions relate to a desired opening position, as suggested in  FIG. 2 , which, on average, is to be achieved by the piston slide  13 . The lower surface  20  of the top part  16  of the drum  2  represents a fixed reference plane, from which the piston slide  13  moves away during the opening. 
   Two radially successive annular chambers  22  and  23  are constructed radially outside the sealing groove  18  in the piston slide  13  and the top part  16  of the drum  2  on both sides of the gap  19 . The chambers  22 ,  23  lie symmetrically in the open condition with respect to a center plane E of the gap  19 , and in the closed condition, symmetrically with respect to the surface  20 . Annular chambers  22  and  23  extend either in a surrounding manner over an entire circumference or at least on a circumference over an area which corresponds with the solids discharge openings  14 . 
   References to the interior and the exterior annular chambers  22 ,  23  apply to the interior and exterior annular chambers in the piston slide  13  and in the top part  16  of the drum  2 . 
   The radially interior annular chamber  22  starts just radially outside the sealing groove  18  in the top part  16  of the drum  2  or at a corresponding point of the piston slide  13  at a sharp edge  24  at a radius r 1  starting from the drum axis M or measurable from a groove edge of the groove  18 . Chamber  22  widens at a radius point r 2  to a maximal axial dimension H 1 , where axial means a direction parallel to the drum axis M and then narrows again to an axial dimension H 4  at a narrowing or bottleneck  25  at a radius point r 3 . 
   A nozzle-type fanning-out chamber  22  is thereby created which, in an average open condition, has a radial dimension r 3 −r 1 , which is more than twice as large as a maximal axial dimension or height H 1 . 
   In the average open condition, the axial dimension of the narrowing  25  is greater than a height or axial dimension of the gap  19 . 
   In the average open condition, the maximal axial dimension H 1  of the fanning-out chamber  22  is smaller, for example, more than 50% smaller than the axial dimension H 2  of the solids discharge openings  14  in the bottom part  15  of the drum  2 . 
   As a result, the solids stream exiting through the gap  19  when the piston slide  13  is open is fanned out widely and impacts largely unbundled on a web of the bottom part  15  of the drum  2 . This has the purpose of minimizing as much as possible the erosion wear on the bottom part  15  of the drum  2  caused by the stream of solid matter. 
   Starting from the narrowing  25 , recesses in the piston slide  13  and drum top part  16  elements widen with an increasing radius, shown as R in  FIG. 1 , to the drum axis M on both sides of the gap  19  almost in the manner of a ring with quadrant geometry to form the radially exterior annular chamber  23 . However, these annular chambers  22 ,  23  widen beyond the axial dimension or height H 2  of the solids discharge openings  14  to an axial dimension H 3  which is larger, possibly more than twice as large, than the axial dimension H 2  of the solids discharge openings  14  in the average open condition. 
   The annular chambers  22 ,  23  then narrow slightly just in front of outer radius r 4  of the piston slide  13 . Then axially, relative to the drum axis M, on both sides of outer edges of the solids discharge openings  14 , chambers  22 ,  23  abut an inner circumferential wall of the bottom part  15  of the drum  2  at the outer radius r 4  at a gap between the piston slide  13  and the bottom part  15  of the drum  2  or between the top part  16  of the drum  2  and the bottom part  15  of the drum  2 . 
   During the exiting of the solids from the interior annular chamber  22 , the solids impact at a high speed on the inner circumferential wall of the bottom part  15  of the drum  2 , so that a portion of the exiting stream of solids is reflected back into the annular chamber  23 . These particles are guided in the annular chamber  23  in the curved manner of arrows P and then exit from the solids discharge openings  14 . Thus, a depositing of solids in an area of these annular chambers  22 ,  23  and/or of the gaps between the bottom part  15  of the drum  2  and the piston slide  13  and the top part  15  of the drum  2  is effectively prevented. 
   In the case of conventional separators, an exit height of the gap  19  is smaller than that of the solids discharge openings  14 . In the present disclosure, the exit height H 3  of gap  19  is larger than a height H 2  of the solids discharge openings  14 . 
   Although the present disclosure has been described and illustrated in detail, it is to be clearly understood that this is done by way of illustration and example only and is not to be taken by way of limitation. The scope of the present disclosure is to be limited only by the terms of the appended claims.