Spiral channel

From there, the reaction flow either leaves the total system to be quenched or, more commonly, enters the next plate which contains a delay loop, a spiral channel [56]. Leaving that plate, the streams flow to the last structured plate containing a bifurcation-mini mixer unit. The streams are distributed in multiple streams and contacted with a likewise split water stream. This leads to fast dilution, e.g., of a concentrated sulfuric acid stream, and rapidly cools the reaction stream. The reaction is quenched more or less initially. The final plate is unstructured and acts as a cover plate with holes for liquid withdrawal (Figure 4.28). 

The baffle forms a continuous spiral channel, section 75 mm x 200 mm. 

The spiral die, commonly used to extrude tubular blown films, eliminates weld line effects and produces a thermally and geometrically homogeneous extrudate. The polymer melt in a spiral die flows through several feed ports into independent spiral channels wrapped around the circumference of the mandrel. This type of die is schematically depicted in Fig. 3.18. 

The MEKC separation of 19 naturally occurring amino acids has been achieved with an impressive average N value of 280,000, mainly because of the use of a 25-cm-long channel. The dispersion introduced by the turn geometry was reduced by using a spiral channel, instead of a serpentine channel. The spiral channel with turns of much larger radius of curvature, rc [339], was akin to that first introduced in a GC chip [1]. 

Fig. E6.5b The synthesis of a flat spiral pump from building block 1. (a) A section of the curved channel formed by a stationary plane and the rotating disk plane (b) the extension of the channel into a flat spiral (c) outside view of the flat spiral pump, with the spiral channel machined into the surface of one disk and another closely spaced rotating disk covering it.

Fig. E6.6b The synthesis of the free rotating flight pump from building block 2. (a) an annular channel is created between the rotating shaft and hollow cylinder (b) the channel is twisted and extended into a helical spiraling channel (c) the channel is formed by a spiral that rotates between a stationary shaft and stationary barrel, with a feed port and exit port machined into the barrel.

Flat Spiral Pump A spiral flight of height H is welded to a stationary disk creating a spiral channel of constant width W, as shown in the accompanying figure. By placing a second disk over the channel, a flat spiral pump is created. Clockwise rotation of the upper disk pumps liquid from the outer inlet port to the inner exit port. Derive an expression for the flow rate of an incompressible Newtonian fluid in isothermal flow. 

A total of WOO thin wafer chips are to be placed in 0.5 dm of 20% HF. If a spiral channel 10 nm wide and 10 m in length were to be etched to a depth of 50 Am on both sides of each wafer, how long should the chips be left in the solution Assume that the solution is well mixed. (Ans. 330 min)... 

FIGURE 12.1 Flat-membrane modules for membrane extraction in flow systems, (a) Spiral-channel membrane module with 1 mL channel volume (A, blocks of inert material B, membrane). (From Jonsson, J.A. and Mathiasson, L., Trends Anal. Chem., 11, 106, 1992. With permission from Elsevier Science.) (b) Straight-channel membrane module with 10 p-L channel volume. (From Lindegard, B., Bjork, H., Jonsson, J.A., Mathiasson, L., and Olsson, A.-M., Anal Chem., 66, 4490, 1994. With permission.)... 

These problems can be solved by making a single or plural spiral channel(s) in a solid disk. In the first model, a single spiral channel is made in a plastic disk, which can be serially connected by stacking multiple disks... 

Table 1 Dimensions of four spiral channels used in the present studies...

The effects of channel geometry on partition efficiency in terms of peak resolution gives a more complex picture in the dipeptide separation with the butanol solvent system, the deeper channel of the single spiral disk (column I) produced a substantially better peak resolution, especially in the lower phase mobile mode (L-I-T), whereas the shallower channel in the four-spiral disks (column IV) produced a somewhat better separation than its counterpart. We do not understand the reason why higher peak resolution is obtained in the deeper channel of column I in L-I-T, despite the low retention of the stationary phase. In protein separation, with the PEG-phosphate system, the shallower spiral channel of the single-spiral disk displayed... 

Fig. 6 Locular column IV. Four spiral channels 1.5 mm (width) x 3.7 mm (depth), each 1 m long, locule 1 cm x 310. (a) 1-Butanol/acetic acid/water (4 1 5). b) (PEG 1000-dibasic potassium phosphate (each 12.5%, w/w).

The rectangular spiral channel embedded in a solid plastic disk, applied to the J-type HSCCC centrifuge, enhances the retention of stationary phase for viscous, low interfacial tension, two-phase solvent systems. Its main advantages are as follows ... 

The system allows further modification of the shape of spiral channels to improve the partition efficiency. 

Spiral channel plate Hybridization at probe-line ... 

FIGURE 3 Intersection approach procedure for 2D microfluidic microarray analysis. (A) Probe line printing with the radial channel plate. (B) Hybridization procedure with die spiral channel plate. Hybridization occurring at the intersections of the spiral channels and radial probe lines, shown as colored patches in die right-most disc. Used with permission from Wang et al. (30). 

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