Hemodiafiltration system and method

A hemodiafiltration process comprising:

• Introducing blood into a blood inlet at one end of a membrane module having a cylinder-shaped housing with a longitudinal extent, in which housing a bundle of hollow-fiber membranes having semipermeable walls and being capable of supporting fluid flow through their lumina is arranged in a direction of the longitudinal extent of the housing, one end of the hollow-fiber membranes being embedded in a fluid-tight manner in a first sealing compound joined to an inner wall of the housing in a fluid-tight manner and a second end of the hollow-fiber membranes being embedded in a fluid-tight manner in a second sealing compound joined to the inner wall of the housing in a fluid-tight manner, and in which housing an exterior space delimited by the inner wall of the housing and the first and second sealing compounds are formed around the hollow-fiber membranes, wherein the exterior space along the longitudinal extent of the housing is divided by a continuous dividing wall into a dialyzate space and a substituate space separated from the dialyzate space in a fluid-tight manner, and the dividing wall encloses each individual hollow-fiber membrane, directing the blood through the lumina of the hollow-fiber membranes, introducing a dialyzate into the dialyzate space, passing the dialyzate along the hollow-fiber membranes, thereby taking up an ultrafiltrate withdrawn from the blood through the walls of the hollow-fiber membranes, withdrawing the dialyzate mixed with the ultrafiltrate from the dialyzate space, introducing a substituate into the substituate space, delivering the substituate to the blood via the walls of the hollow-fiber membranes, and withdrawing the blood from a blood outlet at the other end of the membrane module.

A membrane module comprising a cylinder-shaped housing with a longitudinal extent, in which housing a bundle of hollow-fiber membranes having semipermeable walls and being capable of supporting fluid flow through lumina is oriented in a direction of the longitudinal extent of the housing, one end of the hollow-fiber membranes being embedded in a fluid-tight manner in a first sealing compound joined to an inner wall of the housing in a fluid-tight manner and a second end of the hollow-fiber-membranes being embedded in a fluid-tight manner in a second sealing compound joined to the inner wall of the housing in a fluid-tight manner, such that an exterior space delimited by the first and second sealing compounds and the inner wall of the housing is formed around the hollow-fiber membranes, wherein the exterior space along the longitudinal extent of the housing is divided into a dialyzate space and a substituate space by a dividing wall that encloses each hollow-fiber membrane and runs substantially transversely to the hollow-fiber membranes, wherein the dialyzate space has an inlet arrangement and an outlet arrangement for introducing and withdrawing a dialyzate, and the substituate space has at least one inlet arrangement for introducing a substituate, wherein a sterile filter is arranged in an area of the substituate space between the substituate inlet arrangement and the hollow-fiber membranes located in the substituate space, such that the sterile filter divides the substituate space into an outer substituate-space section and an inner substituate-space section that is spatially separated from the outer substituate-space section, and wherein the outer substituate-space section is in fluid communication with the substituate inlet arrangement and the hollow-fiber membranes are arranged in the inner substituate-space section.