An apparatus for increasing the intrinsic viscosity of a polymer comprising: a chamber adapted to be rotated about an axis and defining a first radial dimension, the chamber defining an internal volume and an internal surface, the chamber having a first end wall and a second end wall opposed to the first end wall, the first end wall having a first aperture defining a second radial dimension smaller than the first radial dimension, the second end wall having a second aperture, the first and second apertures providing access to the internal volume; a first wall having a first end abutting the first end wall, the first wall further defining the internal volume and extending inwardly from and obliquely to the first end wall, the first wall having a distal end spaced axially apart from the second end wall, the first wall defining a first product contacting surface positioned about a portion of the first aperture; and a second wall having a first end abutting the second end wall, the second wall further defining the internal volume and extending inwardly from and obliquely to the second end wall, the second wall having a second product contacting surface positioned about a portion of the second aperture; and wherein the first wall and the second wall extend at an angle to the axis from 10° to 80°, such that the internal volume is defined by an intersection solid formed by a first cylinder and a second imaginary cylinder which is rotated counterclockwise about the center wherein the apparatus is characterized in that the second wall has a distal end located axially between the second end wall and the distal end of the first wall, a chamber adapted to be rotated about an axis and defining a first radial dimension, the chamber defining an internal volume and an internal surface, the chamber having a first end wall and a second end wall opposed to the first end wall, the first end wall having a first aperture defining a second radial dimension smaller than the first radial dimension, the second end wall having a second aperture, the first and second apertures providing access to the internal volume; a first wall having a first end abutting the first end wall, the first wall further defining the internal volume and extending inwardly from and obliquely to the first end wall, the first wall having a distal end spaced axially apart from the second end wall, the first wall defining a first product contacting surface positioned about a portion of the first aperture; and a second wall having a first end abutting the second end wall, the second wall further defining the internal volume and extending inwardly from and obliquely to the second end wall, the second wall having a second product contacting surface positioned about a portion of the second aperture; and wherein the first wall and the second wall extend at an angle to the axis from 10° to 80°, such that the internal volume is defined by an intersection solid formed by a first cylinder and a second imaginary cylinder which is rotated counterclockwise about the center wherein the apparatus is characterized in that the second wall has a distal end located axially between the second end wall and the distal end of the first wall,