Patent ID: 7905253
Filing Date: 2011-03-15
Classification: F16K,Y10T

Abstract:
1. Double seat valve comprising two valve housing parts, and first and second closing elements ( 3 , 4 ) arranged in series and movable with regard to each other, which prevent in a closed position of the double seat valve ( 1 ) fluids from one of the valve housing parts ( 1 a ; 1 b ) flowing into the other of the valve housing parts ( 1 b ; 1 a ), which define in the closed position, as well as in the open position, a leakage cavity ( 5 ), which is connected with the surroundings of the double seat valve ( 1 ), wherein, in the closed position, the first closing element ( 3 ), which is formed as a slide piston, is received in sealing manner in a connecting opening ( 2 c ) extending from one of the valve housing parts to the other and connecting the valve housing parts ( 1 a , 1 b ) with each other and which comes to abut, in a sealing manner in the course of its opening movement, the second closing element ( 4 ), which is associated with a second seat ( 2 b ), through an intermediate seal ( 8 ; 8 *) acting between the closing elements ( 3 , 4 ), and the second closing element is also transferred to an open position (H) during a further opening movement, the first closing element ( 3 ) comprising a first seal ( 6 ), which seals radially against a cylindrical first seat ( 2 a ) formed in the connecting opening ( 2 c ), the cylindrical first seat being coaxial with the second seat, each of the closing elements ( 3 , 4 ) being able to be transferred independently from the other by a partial lift to a seat cleaning position in order to rinse its respective coaxial seat ( 2 a , 2 b ), wherein the second closing element ( 4 ) can be transferred to its seat cleaning position by a second partial lift (T 2 ) in the same direction as the opening movement and the first closing element ( 3 ) can be transferred to its seat cleaning position by a first partial lift (T 1 ) in the direction opposed to the opening movement, wherein the first partial lift (T 1 ) generates a first seat cleaning flow (R 1 ), and the second partial lift (T 2 ) generates a second seat cleaning flow (R 2 ), a cylindrical lug ( 3 *, 4 *) being arranged at each closing element ( 3 , 4 ) on a side of the closing element adjacent to a leakage cavity defined between the closing elements, each cylindrical lug forming an annular choke gap (D 1 , D 2 ) with the connecting opening ( 2 c ) that is the smallest gap between the connecting opening and the closing element on which the cylindrical lug is formed when the closing element is in its seat cleaning position, the first seat ( 2 a ) comprising a diameter that is smaller than the diameter of an annular recess ( 2 d ) in the connecting opening ( 2 c ), the annular recess being associated with the second closing element ( 4 ), and a transition surface ( 2 e ) between the first seat ( 2 a ) and the annular recess ( 2 d ), characterised in that, in the closed position of the second closing element ( 4 ), a stop face ( 4 e ) arranged at a front face of the cylindrical lug ( 4 *) of the second closing element abuts against the transition surface ( 2 e ; 2 e *), and in that, directly adjacent to the first seat ( 2 a , 2 g ), in the front face of the second cylindrical lug ( 4 *), a central recess ( 4 d ) is provided, which starts radially on the outside with a rotationally symmetrical fluid flow diversion area ( 4 b ) having a surface contour (K) and has a front face ( 4 c ) oriented substantially perpendicular to the longitudinal axis of the second closing element ( 4 ), said fluid flow diversion area ( 4 b ) leading into the front face ( 4 c ), the fluid flow diversion area ( 4 b ) and the stop face ( 4 e ) form a second rounded edge (U 2 ), which is directly adjacent to a first end section ( 2 g ) of the first seat ( 2 a ) in the closed position of the second closing element ( 4 ), viewed in vertical center section, the fluid flow diversion area ( 4 b ) comprises a contour (K) with an uncurved portion, wherein a direction vector of a fluid flow outlet of the fluid flow diversion area ( 4 b ) points into a discharge bore ( 3 d ) centrally arranged in the first closing element ( 3 ) without intersecting with either the first closing element ( 3 ) in an area of the first closing element bounding the leakage cavity ( 5 ) or the intermediate seal ( 8 ; 8 *) and thus without forming impact pressure, and wherein a frontal boundary of the first closing element ( wherein the connecting opening ( whereby, when the first closing element is in its seat cleaning position, the first seat cleaning flow flows from the choke gap associated with the first closing element and through the fluid flow diversion area to the leakage cavity, the first seat cleaning flow entering the fluid flow diversion area shock-free.