Fluid-directing multiport rotary valve

A multiport rotary valve for directing fluid streams comprising:

• (a) a first head having opposed surfaces, comprising at least two first ports located on the same surface for connection with an external fluid stream, and having a separate channel associated with each first port leading to a second port corresponding to the first port and located on the surface opposite the first port;
• (b) a rotatable second head having at least two third ports each in communication with a separate second port and channel and located on a surface in contact with the surface of the first head containing the second ports, said third ports leading to an inlet or outlet of a chamber containing a fluid-solid contacting medium so as to form a fluid seal between the chamber and an external fluid stream;
• and
• (c) a drive for rotating at least one of said heads to interconnect a selected external fluid stream with a selected chamber for a predetermined period of time before permitting interconnection of said external fluid stream with a different chamber;
• (d) the ports being configurable to permit said external fluid streams to be delivered to multiple or successive chambers in series or in parallel or to bypass a selected chamber simultaneous with the delivery of other external fluid streams;
• wherein a position sensor is used to control the position of the rotatable head relative to the first head.