Plain Square meshes

FIG. 6-16 Screen discharge coefficients, plain square-mesh screens. Couttesy ofE. I. du Pont de Nemours [Pg.646]

The discharge coefficient for the screen C with aperture D, is given as a function of screen Reynolds number Re = Ds(Wa)p/p in Fig. 6-16 for plain square-mesh screens, a = 0.14 to 0.79. This curve fits most of the data within 20 percent. In the laminar flow region, Re < 20, the discharge coefficient can be computed from... 

Grootenhuis (Proc. Inst. Mech. Eng. [London], A168, 837—846 [1954]) presents data which indicate that for a series of screens, the total pressure drop equals the number of screens times the pressure drop for one screen, and is not affected by the spacing between screens or their orientation with respect to one another, and presents a correlation for frictional losses across plain square-mesh screens and sintered gauzes. Armour and Cannon (AIChE J., 14,415-420 [1968]) give a correlation based on a packed bed model for plain, twill, and dutch weaves. For losses through monofilament fabrics see Pedersen (Filtr. Sep., 11, 586-589 [1975]). For screens Inclined at an angle 0, use the normal velocity component V ... 

FIGURE 13.1 Model Predicted Liquid Hydrogen Bubble Point Pressure Over the Anticipated Operating Range of a Cryogenic Fuel Depot for (a) Five Finest Dutch Twill, (b) Coarse Dutch Twill and Plain Dutch, and (c) Twilled and Plain Square Mesh Screens. All curves assume GHe pressurant and Tgas=Tuquid-... 

There are a number of different filter materials. Wire screens are the most common. Several t5 es of wire screens are available, such as the square mesh with plain weave and the square mesh with Dutch twill. There are also depth filtration media, such as sintered metal powder and random metal fibers. Advantages and disadvantages of different filter materials are shown in Table 1. 

The key dimensions of wire mesh are illustrated in Figure 2.8, for plain weave and square mesh (the usual form for plain woven wire meshes). Aperture width, w, is the distance across the aperture, between the bounding wires, measured in the projected plane at the mid positions. The wire diameter, d, is the diameter of the wire forming the mesh. The pitch, p, is the distance between the middle points of two adjacent wires and therefore is the sum of the aperture width and the wire diameter ... 

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