Patent ID: 7600535

Claim:
A valve unit for switching fluid paths in a pressure exchanger installation having at least two pressure exchangers through which flow occurs alternately, wherein said valve unit comprises a rotatable control element arranged within a housing and a plurality of flow paths inside walls of said housing, said housing having a plurality of connections for connection lines and being connected via respective ones of said connections to a first pipe system and to a respective end of at least one pressure exchanger; another end of each pressure exchanger being connected through an intermediate valve to a second pipe system; said control element being divided into a high pressure chamber and a low pressure chamber and provided with a motor-driven drive shaft for rotating the control element, and the high pressure chamber and low pressure chamber of said control element being alternately connected to the flow paths inside the housing walls and the connections arranged on the housing such that by switching the position of the control element the high pressure chamber is alternately connected to one or the other of the at least two pressure exchangers while the low pressure chamber is alternately connected to the other or the one of the at least two pressure exchangers so that incoming high-pressure fluid flows from the high pressure chamber to one of the pressure exchangers while low-pressure fluid flowing out of the other of the pressure exchangers is conducted through the low pressure chamber to the connection for outgoing low-pressure fluid or vice versa; wherein said control unit connections include a connection for incoming high-pressure fluid leading to the high-pressure chamber of the control element, a connection for outgoing low-pressure fluid leading from the low-pressure chamber and connections for the at least two pressure exchangers which by rotation of the control element are each alternately connected to the high-pressure chamber and low-pressure chamber; wherein a supply flow takes place from the connection for incoming high-pressure fluid in an axial or radial direction to the high pressure chamber of the control element within the housing and a discharge flow of the low-pressure fluid takes place in the axial direction from the low pressure chamber of the control element to the connection for the outgoing low-pressure fluid; wherein control openings arranged in the control element in communication with the high-pressure chamber have an opening angle which differs from the corresponding flow openings of the housing in order to charge the pressure exchanger in effective communication with the valve unit with a high pressure from the supply opening during the switching of the control element, and wherein the control element has a hollow cylindrical configuration and is divided into said high-pressure and low-pressure chambers by a separating wall.