Flow-diverting rotary valves of multiple paths

#The present invention relates to a rotary valve for diverting multiple fluids to different receivers in a sequential and cyclic manner.

#In a number of fluid delivery processes, a flow passage is required to sequentially receive n fluids one after another from the 1st fluid to the nth fluid and to repeat the process endlessly in a progressive and cyclic manner. If multiple flow passages are required to go through the same process simultaneously, as in the case of the simulated moving bed chromatography, the operation is very complex and a special fluid diverting device is needed.

#U.S. Pat. No. 3,706,812 describes a rotary valve for this process. The rotary valve comprises three basic parts: a stationary disc, a rotating disc, and a stationary collar ring. The lower face of the stationary disc and the upper face of the rotating disc are in close contact to form a first leak-proof seal and the interior of the stationary collar ring and the exterior of the rotating disc are in close contact to form a second leak-proof seal. The stationary disc has inlet ports on its upper face and circular grooves concentrically spaced apart on its lower face, each inlet port is in communication with one corresponding circular groove. The rotating disc has radial flow passages with inlet openings on the upper face and the outlet openings spacing apart equally on the exterior. The stationary collar ring has outlet ports and each outlet port is in communication with one of the outlet openings of the flow passages of the rotating disc. The inlet openings of the rotating disc locate at different radial distances from the axis of the rotating disc and the radial distances correspond to the radius of the respective circular grooves so that each inlet opening of the rotating disc is always connected with a corresponding circular groove of the stationary disc as the rotating disc rotates. In this way, a fluid will flow in the valve from the same path in the stator and the rotator (from an inlet port, through a concentric groove, an inlet opening, a flow passage, to a outlet opening) but is diverted into different outlet ports of the stationary collar ring. Multiple fluids can be diverted to different outlet ports in a simultaneous, progressive, and cyclic manner by stepwise turning the rotating disc of the rotary valve.

#FIG. 1 is a cross-sectional view of the rotor, the stator, and the assembled valve of one embodiment;

#FIG. 2 is a cross-sectional view of the rotor, the stator, and the assembled valve of another embodiment;

#FIG. 3 is a cross-sectional view of the assembled vale of another embodiment;

#For exemplary purpose, all Figures for the preferred embodiments have four flow paths for diverting four fluid streams. It should be realized that the valve of the present invention are able to simultaneously divert more fluid streams and the number of flow paths of the valve is not a limit of the present invention.

#FIG. 1 shows one embodiment of the present invention. The embodiment comprises a stator S and a rotor R that is positioned within stator S. Stator S has a top end 11, a bottom end 12, a lateral exterior surface 13, a circular cavity 14 with an lateral interior surface 14a, and a plurality of external ports extending from lateral exterior surface 13 to the lateral interior surface 14a. Said ports are grouped into group A of 4 ports and group B of 4 ports. The ports of group A are designated as port A1 to A4 and are spaced apart longitudinally from said top end 11. Ports of group B are designated as ports B1 to B4, are located approximate to the bottom end 12 on a common plan perpendicular to the axis of said circular cavity 14, and are equally spaced apart along the circumference of said circular cavity 14. Rotor R is of column shape and has a top end 21, bottom end 22, a lateral exterior surface 23, and four internal flow passages F1 to F4. Rotor R is positioned in circular cavity 14 rotatable about the axis of the circular cavity. Each of said internal flow passages F has a top opening Cx and a bottom opening Dx on the lateral exterior surface 23 of rotor R wherein x is an integer variable. Openings C are spaced apart longitudinally from top end 21 of rotor R in such a way that when rotor R is assembled into stator S each opening C is paired with a corresponding port Ax of stator S on approximate the same plan of the later perpendicular to the axis of said circular cavity 14. A plurality of ring structures 24 extend from lateral exterior surface 23 along the rotor circumference on plans perpendicular to the axis of circular cavity 14 of stator S. Ring structures 24 locate respectively above the first opening C1, below the last opening C4, and between each neighboring pair of the openings C1 to C4. Ring structures 24 rotatablly seal the interstice between the lateral exterior surface 23 of rotor R and the lateral interior surface 14a of circular cavity 14 of stator S to form four circular flow channels E1 to E4 that are spaced apart longitudinally. Openings D1 to D4 of rotor R are located on the same plan as ports B of stator S, equally spaced apart along the circumference of rotor R, and aligned with corresponding ports B to form multiple flow paths that extend from ports A, through circular flow channels E, top openings C, internal flow passages F, bottom openings D, to ports B of the stator wherein receivers are connected. A conventional means for leak-proof connection between a stationary member and a rotating member is preferably adapted to the connections between openings D and ports B that includes but not limits to o-rings, graphite discs, and closely contacting surfaces.

#To divert four fluid streams with the valve depicted in FIG. 1, rotor R is turned relative to stator S by 90 degrees each time to simultaneously divert four fluid streams from the current receivers to the next receivers. A first fluid entering port A1 of stator S, correspondingly through circular flow channel E1, top opening C1, internal flow passage F1, bottom opening D1, to port B1 of stator S where receiver 1 is connected. Simultaneously, the remaining three fluid streams flow through corresponding flow paths of said valve to the corresponding receivers. After rotating rotor R by 90 degrees in respect to stator S, port A1 of stator S remains its connection to circular flow channel E1 of rotor R but bottom opening D1 of rotor R is now connected to port B2 of stator S. Said first fluid still enters port A1 of stator S, correspondingly through circular flow channel E1, top opening C1, internal flow passage F1, bottom opening D1, but to port B2 of stator S where receiver 2 is connected. The first fluid is thus diverted from port B1 to port B2. Simultaneously, the rest fluids are diverted to the next corresponding receivers. Said first fluid is diverted back to port B1 again for a new round of fluid diversion after the rotor rotates 4 times to complete a revolution.