Multipass spacing

CVSS models introduced in Section 4.5 for process data with strong autocorrelation and crosscorrelation. One-step ahead residuals generated from the CVSS model will be used for sensor audit. A multipass version of the technique is developed to identify submodels by eliminating successively the corrupted measurements from both the calibration and test data sets and fitting a different CV state-space model. 

Intermediate pressure. Noncorrosive vapor. Severe coolant or moderate vapor fouling. Can handle freezing condensate. Tube vibration problems. Multipassing and variable baffle spacing can be used for total condensation. Good venting control. 

The entire assembly is enclosed in a highly insulated cold box to conserve energy. The columns must be made as compact as possible to minimize capital investment as well as reduce heat leak. Up to 150 distillation trays are used in a double column system and tray spacings are kept small at 10 to 20 cm. The trays are typically multipass sieve trays with small diameter perforations. Because the distillation is an extremely clean service, perforations are typically as small as 1 mm. Many tray geometries are used, including multipass cross-flow, split cross-flow (parallel) and circular flow (race track) trays. Each has certain attributes which are used to optimize the column design for different design conditions. 

Mass Resolution In TOF-MS, mass resolution is related to the temporal width of the isomass ions packet when that packet arrives at the detector (i.e., R = t/At). In the ion source, ions are accelerated out of the source region with inherent dispersion in time (instant of ion formation), space (location of ion at the time of acceleration), and velocity (owing to differences in the initial kinetic energy of ions). These are the three primary factors that limit the resolution in a TOP instrument [11, 13, 16]. The initial kinetic energy (KE) of ions (i.e., KE before acceleration) is given by KE = where no is the initial velocity, which will be in a random direction after acceleration, KE = gV + mvl. The temporal dispersion creates uncertainty in the ions arrival time at the detector. The contribution of this factor can be minimized by the use of a very short ionization pulse and/or a fast-rise ion-extraction pulse, and also by increasing the flight path. Multiturn and multipass research TOP mass spectrometers are available to... 

The annulus between primary and secondary containment is provided with multipass filtration and recirculation within the secondary containment space. A small negative pressure is maintained in it by purging to stack via filters. This effectively stops any ground level release of activity from RB to environment. 

---