Abstract: An uncontrollable dehydrator where the uncontrollable discharge is augmented with a purge gas to increase the capacity of the dehydrator to achieve a target flow rate and dew point.

Abstract: A capillary membrane gas dehydrator. A gaseous stream having water vapor therein flows into the tube side of the capillaries. Water vapor permeates through the fibers to the shell side. A portion of the dehydrated stream is used as a purge stream for the shell side of the dehydrator. A pressure valve meter combination is used in the bypass stream to ensure that the pressure of the purge stream is maintained at a constant level independent of any variation in the pressure of the feed stream. This ensures that if there is an increase in pressure in the feed stream there is no increase in the purge rate and no corresponding increase in purge losses.

Abstract: A meter for measuring the brightness and/or consistency of pulp slurry. An optical probe introduces light energy into the slurry, which energy is transmitted and back-scattered, and reflected orthogonally. Three signals are provided which correspond to the back-scattered, reflected, and transmitted energy. Each of the signals is ratioed against a reference signal which corresponds to the intensity of the energy introduced into the slurry to provide three outputs proportional to the difference between the reference signal and the received signals. The output corresponding to the back-scattered energy is multiplied by the log of the output corresponding to the transmitted energy to produce a measurement of brightness independent of consistency. The output corresponding to the back-scattered energy is divided by the log of the output corresponding to the reflected energy to produce a measurement of consistency which is independent of the pulp brightness.