Flow Sheet Setup

The flow-sheet of the experimental setup is shown in Figure 1. The details are reported elsewhere (Palmisano et al., 2007b). A cylindrical batch photoreactor of Pyrex glass with immersed lamp was used for fhe phofocafalyfic runs of benzyl alcohol and phenol oxidation. On the top of fhe reacfor fhree porfs allowed the inflow and outflow of gases, fhe pFl and femperafure measurements, and the withdrawal of samples for analysis. 

The overall model of an SMB process is developed by linking the models of individual chromatographic columns (Section 6.2). As with the chromatographic batch process, the plant setup of Figure 6.35 is converted into a simulation flow sheet. Figure 6.36 shows the SMB column model. 

In a new case in Hysys, add the components ethane and water, and select the appropriate fluid package (NRTL). Enter the simulation environment and mix the two streams as shown in Figure 1.39. The Workbook is used to display the stream summary table below the process flow sheet. Click on Workbook in the toolbar once the workbook appears, click on Setup in the Workbook menu, and then click on Add to add the required variables from the list of variables. Once all information required is added to the workbook, right click anywhere in the PFD area and select Add Workbook Table. 

Stream summary results can be displayed on the process flow sheet by clicking on Report Options under the Setup folder. Then click on the Stream folder tab. For detailed data, make sure that both the boxes beside Mole and Mass contain a checkmark. Also, make sure that both the boxes are checked under Fraction basis. Click on Next. For summary results, just check the box below mole fraction basis (Figure 3.4). 

Figure 29.3 Experimental setup and instrumentation 1 — fuel 2 — oxidizer, N2, seed-particles 3 — plenum chamber 4 — flow straightener 5 — c/d nozzle (Dthroat = 19.0 mm, Dexu = 24.7 mm) 6 — cavity 7 — laser sheet 8 — Mie-scattering collection device 9 — CCD 10 — afterburning flame and 11 — microphone...

Figure 2 Diagram of a generalized 2D-PIV setup showing all major components flow channel with the particle seeded fluid flow, laser sheet pulses illuminating one plane in the fluid, a CCD camera imaging the particles in the laser-illuminated sheet in the area of interest, a computer with PIV software installed, a timing circuit communicating with the camera and computer and generating pulses to control the double-pulsed laser. The PIV software setups and controls the major components, and analyses the images to derive a vector representation of flow field (see Plate 4 in Color Plate Section at the end of this book).

To clarify the mutual interactions between the gas bubbles and its surrounding liquid flow (mostly turbulent) in a bubbly flow, information of bubble s shape and motion is one of the key issues as well as the surrounding liquid velocity distribution. Tokuhiro et al. (1998, 1999) enhanced the PIV/LIF combination technique proposed by Philip et al. (1994) with supplementation of SIT to simultaneously measure the turbulent flow velocity distribution in liquid phase around the gas bubble(s) and the bubble s shape and motion in a downward flow in a vertical square channel. The typical experimental setup of the combination of PIV, LIF, and SIT is shown in Figure 14. The hybrid measurement system consists of two CCD cameras one for PIV/LIF (rear camera) and the other for SIT (front). The fluorescent particles are Rhodamine-B impregnated, nominally 1-10 pm in diameter with specific density of 1.02, and illuminated in a light sheet of approximately 1 mm thickness (Tokuhiro et al., 1998,1999). The fluorescence is recorded through a color filter (to cut reflections) by the rear camera. A shadow of the gas bubble is produced from infrared LEDs located behind the gas bubble. A square "window" set within the array of LEDs provides optical access for... 

Once the process has been optimized, plastic conditions should be recorded such as fill time, peak pressure at fill, cavity pressure,184 melt temperature, mold temperature, melt flow rates, and gate seal time. Record all basic machines setpoints on the setup sheet such as the transfer time (fill time) and weight, overall cycle time, and total shot weight, part weight, % runner, etc. 

Classically, flat-sheet porous PTFE or polypropylene membranes are used as support for the membrane liquid and mounted in holders (cells, contactors) permitting one flow channel on each side of the membrane [1,3,6,8,25]. See Figure 12.1. Such membrane units are typically operated in flow systems and in principle apphcable to aU versions of membrane extraction for analytical sample preparation or sampling. Such a setup can be easily interfaced with different analytical instmments, such as HPLC and various spectrometric instmments, and thereby provides good possibdities for automated operation. Drawbacks of this type of devices are relatively large costs and limited availability, as well as some carryover and memory problems as the membrane units are utilized many times, necessitating cleaning between each extraction. 

As single-hole nozzle plates, circular orifice disks, typically 200 pm thick, with the nozzle hole in the center, are equally suitable as thin metal sheets, as used, e.g., for spatial filtering in optical setups. Thicker disks are best suitable as orifice plates if the hole exhibits a tapered (inlet) region on one side and has its nominal diameter only on a short part of the plate thickness. This feature ensures low flow resistance and good directional stability of the jet. Figure 26.9 shows typical shapes of nozzle cross section profiles [41]. 

Generally there are two possibilities for the illumination of flows whereby the most common is the illumination with a light sheet perpendicular to the camera axis. Especially in microscale divices, e.g. microchannels, it is often not possible to generate a hght sheet with a thickness of a few micrometers because there is either no optical access or reflexions from the close-by wall disturb the optical path. For that reason the whole volume is illuminated and the measurement depth is defined by the depth of field of the optical setup. 

One method to reduce the measurement depth was applied by Mielnik and Saetran by using a selective seeding of a thin fluid layer within an other vise partide-free flow [13]. In analogy with the laser sheet in macroscale PIV, the generated partide sheet deflnes both the depth and the position of the measurement plane, independent of the details of the optical setup. Mielnik and Saetran used selectively seeded J,P IV to measure the instantaneous velocity Add in a microchannel with a depth-wise resolution of 20% below the estimated optical measurement depth of the j,-PIV system. Mielnik and Saetron supposed that a measurement depth corresponding to the diameter of the tracer particles can be achieved [13]. 

A mixture of caffeine and acetaminophen was resolved on TLC silica gel 60 aluminum sheets in two development steps. In the first step, the mobile phase consisted of cyclohexane/acetic acid/trichloromethane (86 7 7), whereas in the second step, it consisted of cyclohexane/methanol/acetic acid/ethyl acetate (59 6 6 29). The TLC plate was than ablated with a laser (213 nm) in an ablation cell. The ablated sample material was transferred to an APCI source by nitrogen flow through polyamide tubing. This setup allowed for spatially resolved analysis of a TLC plate. The position and the shape of the fluorescence signal spots were consistent with the ion images for caffeine (m/z 195) and acetaminophen (m/z 152). Furthermore, an intensity increase from the outside to the inside of the spots was perceived in the ion images of these compounds. These increases in intensity indicate an increase in the amount of analyte in the sample and allow for the estimation of the relative amount of the analyte [56]. 

---