Often, during the distillation of liquid mixtures, some noncondensable gases are dissolved in the feed to the tower. these noncondensables come out of solution when heated in the tower and may accumulate in the overhead reflux drum. in order for the column to operate satisfactorily, these vapors must be periodically vented to a flare or stack. one method to achieve this venting process is to implement a control scheme in which a process control valve is placed on the vent line from the reflux drum. a pressure signal from the drum is used to trigger the opening or closing of the vent line valve. sketch the basic control loop needed for this venting process on a process flow diagram representing the top portion of the tower.

11 players on a field that has a maximum of 11 players

water at room temperature is flowing through a pipe with pressure taps located 10 ft apart along one section of the pipe, which are connected to a mercury (s=13.6) manometer.

most historians agree that gabriel mouton, the vicar of st. paul’s church in lyons, france, is the “founding father” of the metric system. he proposed a decimal system of measurement in 1670. mouton based it on the length of one minute of arc of a great circle of the earth (now called a nautical mile, 1852 meters). he also proposed the swing-length of a pendulum with a frequency of one beat per second as the unit of length (about 25 cm). a pendulum beating with this length would have been fairly easy to produce, thus facilitating the widespread distribution of uniform standards. over the years, his work was revised, improved, and extended by a number of french scientists.

the political sponsor of weights and measures reform in the french revolutionary national assembly was the bishop of autun, better known as talleyrand. under his auspices, the french academy appointed several committees to carry out the work of developing a usable system of weights and measures for france. one of the committees recommended a decimalized measurement system based upon a length equal to one ten-millionth of the length of a quadrant of the earth’s meridian (i.e., one ten-millionth of the distance between the equator and the north pole).