Square screen weave

Square-mesh cloth is the conventional type of screen cloth, but there are many types of cloth with an oblong weave. This latter construction provides greater open area and capacity and in addition makes it possible to use stronger wire for the same size of screen opening and for the same percentage of open area. 

Table 11.1 Typical Flow Opening Sizes and Wire Diameters for Common Size Square-Weave Screens...

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 ... 

Other patented (nonporous) methods to provide support for thin membranes include the cylindrical screens for supporting thin membrane tubes of Bonnet [22], the metal gauze of Juda and Novack [23], the Dutch weave wire netting of Yamauchi, et al. [24], the circular screens of Bonnet [25], the perforated conduits of Eguchi et al. [26], the helical wires of Hollister and Stiles [27], the square perforations of Prolss [28], the corrugated screens of Iniotakis et al. [29], and the var-... 

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 Twilled Square weave is the second most complex style the warp and shute wires are also the same diameter, but each shute wires passes over two warp wires before going under the next two warp wires. The pattern then repeats. The Plain Dutch weave has the same pattern as the Plain Square, but the warp wires are larger in diameter than the shute wires, which creates smaller pore sizes. The Reverse Dutch weave is the inverse of the Plain Dutch the shute wires are larger than the warp wires. Lastly, the most complex screen... 

Table 3.2 lists values for warp and shute wire diameters, along with calculated values for the screen thickness, surface area to volume ratio, eind void fraction, for edl available screens in the literature. Values of d and ds are obtained from the literature (Armour and Cannon, 1968 Paynter, 1970 Heckman, 1971 Burge and Blackmon, 1973b Cady, 1973) or from industry, where available. Tortuosity values are 1.0 for Plain Square and Twilled Square weaves and 1.3 for Reverse Twill, Plain Dutch, and Twilled Dutch weaves. 

Filtration is accomplished with wire mesh screens (square or twill weave), sintered powder, or sintered metal fibers. Table 12.5 shows a comparison of the various filtration media and their characteristics. Square weave screen. Fig. 12.50, has every other wire... 

Characteristics Square Weave Screen Dutch Twill Weave Screen Sintered Powder Metal Fiber... 

---