Equal pressure drop

Li and Manas-Zloczower (31) used the CFM commercial FIDAP FEM package to simulate the three-dimensional isothermal flow patterns and distributive mixing in three consecutive filled, closed C-shaped chambers of fully intermeshing, counterrotating extruders, having the dimensions of Leistritz 30.34 (30 denotes the centerline distance and 34 the barrel diameter in mm units). An equal pressure drop per C-shaped chamber was applied for the calculations. The melt was assumed to be Power Law above y() and Newtonian below it. The design, process, and material variables are given by the authors. 

Island with the manifold serves to create an equal pressure drop from the die inlet to all points across the die exit. 

Figure 8. Alternative gasket slot feeding arrangement for equalizing pressure drop and supporting membrane...

Figure 3.13. The particle diameter as a function of the axial dispersion ct, for various residence times / assuming constant reactor length L = 25 cm. The dashed lines connect points with equal pressure drop. The hatched areas indicate pressures that cannot be sustained by a peristaltic pump. (From Ref. 74 by courtesy of Elsevier Scientific Publishing Co.)...

MF flow distribution, splitting one flow into four using channel length to create equal pressure drop. Equal flow distribution is attained by 8% relative variation. 

Since this runner system comes out of the mold as the part is ejected, it is known as a cold runner. Ideally, the runner system provides the shortest path possible to each part with equal flow distance and equal pressure-drop to each... 

Reaction design A stage design approach characterized by an approximately equal pressure drop in the nozzle and associated bucket. 

In the reaction design, approximately equal pressure drop occurs in the nozzles and buckets. To reduce the associated axial thrust on the rotor, a drum construction is used with the reaction design, as shown in Fig. 6.80. Even with a drum rotor, it is usually necessary to build a balance piston into the rotor to balance the stage thrust, unless the turbine section is double-flowed. 

Figure 2.5a. Reactor for high-throughput testing of catalytic materials at temperatures up to about 1,200 °C (e.g. for HCN formation from methane and ammonia using capillaries to compensate for equal pressure drop in all reactor channels (Moehmel et al, 2008).

Runner layouts should be designed to deliver the plastic melt at the same time and at the same temperature, pressure, and velocity to each cavity of a multicavity mold. Such a layout is known as a balanced runner (Fig. 7.15). A balanced runner will usually consume more material than an unbalanced type, but this disadvantage is outweighed by the improvement in the uniformity and quality of the moldings. Balance in a multi-cavity mold with dissimilar cavities (known as a family mold) can be achieved by careful variation of runner diameter in order to produce equal pressure drops in each flow path. Such balancing can only be achieved efficiently by the use of computer flow simu-... 

Fluidization occurs when the fluid flow rate is great enough so that the pressure drop across the bed equals the weight of the bed. As stated previously, the solids film thickness adjacent to the wall is difficult to measure and/or predict. Wen and Fan [Chem. Eng., 64(7), 254 (1957)] give external walls ... 

York and Poppele (R-17) have suggested that total pressure drop through the mesh is equal to the sum of the mesh diy pressure drop... 

The catalyst bed that was charged to the reactor is now a restriction, calibrated for flow vs. pressure drop. The pressure drop equals the pressure generated by the blower, which in turn depends on the RPM. In essence, the differential pressure measurement was eliminated by calibrating the flow directly with RPM. 

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