Woven wire

Woven media can be called woven wire, woven fabric, wire mesh, wire cloth etc. Precision woven wire cloth is a versatile, wear-resistant filter medium which has been widely used for many years and is available in a large variety of weaves made from many metals. The most frequently used metal is stainless steel, in either type 304 or type 316. The basic difference between the two types is the addition of molybdenum to the type 316 for increased corrosion resistance. Both are otherwise 18-8 alloys, i.e. 18% chromium and 8% nickel. Acmally type 304 is 18-20% chromium and type 316 is 16-18% chromium. 

Woven wire lends itself easily to fabrication of pressure filter leaves and filter baskets. It is easily applied to filter dmms. It is resistant to blinding and is easily cleaned. Stretching or shrinking is non-existent. It usually costs more than non-metallic media, but usually has a long life which helps to off-set the cost along with the other factors above. 

Another use for woven wire is for cleanable cartridge filters with nominal ratings from 300 to 1 rm. Although the use of metal media is expensive, the cartridge can be chemically cleaned and re-used. The aircraft and aerospace industries have been big users of these types of elements. 

When the twilled weave is woven with multiple wires in both warp and shute, it results in a strong, dense fabric known as braided, basket or multibraid weave. The mesh openings are irregular because the multiple shute wires have a tendency to twist around each other. 

With a twilled Dutch weave the mesh count of the warp wires is much lower than that of the shute. The shute wires pass over two and under two wires in both directions. They are pushed together such that one shute wire is on top of the next one, which is directly under the warp wire. This yields 

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Data for dry screening on a 20-mm square aperture vibrating screen (8) indicate that the screen is relatively efficient, giving an apparent bypass value of 0.5%, sharpness index of 0.8, and a cut size of 20 mm. On the other hand, results (9) from a plant operating an 8 ft x 20 ft (2.4 m x 6.1 m) double-deck screen with 16 mm woven wire bottom screen deck gave an apparent bypass of 4%, sharpness index of 0.56, and a cut size of 17 mm. Data (10) for smaller... 

Conveyors may be of parallel-chain, mat, slat, woven wire-mesh belt, or cast-alloy type. Automatic tensioning devices are used to maintain belt tension during heating and cooung. The product may rest directly on the conveyor or on special supports built into it. RoUer-conveyors are used for large pieces. Flame curtains are provided for sealing the ends and for protection of special treating atmospheres. 

The screening surface may consist of woven-wire, silk, or plastic cloth, perforated or punched plate, grizzly bars, or wedge wire sections. 

Screen Surfaces The selection of the proper screening surface is veiy important, and the opening, wire diameter, and open area should all be carefully considered. The four general types of screening surfaces are woven-wire cloth, silk bolting cloth, punched plate, and bar or rod screens. 

Sieving Methods and Classification Sieving is probably the most frequently used and abused method of analysis because the equipment, an ytical procedure, and basic concepts are deceptively simple. In sieving, the particles are presented to equal-size apertures that constitute a series of go-no-go gauges. Sieve analysis presents three major difficulties (1) with woven-wire sieves, the weaving process produces three-dimensional apertures with considerable tolerances, particularly for fine-woven mesh (2) the mesh is easily damaged in use (3) the particles must be efficiently presented to the sieve apertures. 

Woven wire cloth is available in a broad range of alloys with mesh counts as coarse as 1" in most alloys and as fine as 635 in some alloys. The following is a list of alloys normally used ... 

The woven wire mesh type are formed to control the open space between the wires, thereby limiting the maximum size particle that can pass through. The cartridge is installed in cases or small vessels to facilitate quick replacement, or they can be arranged for backwash by use of proper piping connections. The wire wound units have consistent spaces for uniform particle size filtering. 

Figure 4-77A. Woven wire mesh filter cartridges. By permission, AMF Corp., Cuno Div., Catalog MP-20.1.

The pressure drops for these units are typically low, ranging from 0.2 to 10-15 psi. The woven wire mesh runs even lower in pressure drops for the same or larger flow rates. Consult the manufacturers for specific application data. 

This packing is woven wire mesh with the following characteristics as reported by the manufacttirer/licensee [lOOj ... 

This packing is a woven wire fabric of parallel corrugated elements and is completely self-wetting. It does not require pre-flooding to attain the wetted condition. This packing has a flat surface of approximately 150 ft /ft, and a free area > 90%. 

Strainers are usually made from woven wire gauze, like a sieve, and though today the pre-size can be made very small indeed (BSI 300 mesh gauze separates particles of roughly 50 microns) they are mainly included for the exclusion of large particles. Filters deal with the removal of very much smaller particles. 

Cotton Wool I O f Polypropylene Nylon Nomex (hl h temp. Nylon) Rayon Dynel Teflon Paper 1 Sintered Metal Woven Wire Cloth Porous Ceramics... 

DRY SIEVING OR SCREEN ANALYSIS WOVEN WIRE SIEVES... 

Fine Series1 — Nominal Dimensions, Permissible Variations, and Limits for Woven Wire Cloth of Standard Sieves... 

Ferrous reinforcing (rebar rods and woven wire meshes). 

The use of metal reinforcement embedded in the slab increases its strength. Woven wire mesh is the most common material for residential applications. For slabs on grade the Council of American Building Officials,32 One and Two Family Dwelling Code recommends 6x6 in.-W2.9 x W2.9 woven wire mesh. To help control cracking, it has been suggested that this is appropriate for a basement slab as well. 

The matrix can be taken away by HN03 except at the ends of the wire, to allow easy soldering. Below IK, the electrical contact can be done also by squeezing the wires to be connected inside a thin A1 tube (see, for example, Section 12.4). For low-level signals, shielded twisted pairs or cryogenic coaxial cables are used. When thousands of wires are necessary, as in large experiments, Kapton strips with deposited conductors [3] or woven wires [4] are used. 

We have already encountered Thomas Midgley, Jr., who came from an inventive family. His father was an inventor in woven wires, bicycles, and detachable tires. His mother s father invented the inserted-tooth saw (McGrayne 2001). Midgley graduated from mechanical engineering at Cornell University in 1911. He did the minimum amount of work with whieh he could get by in most of his courses, so that he could concentrate... 

Three basic types of catalysts were studied in these experiments Pt-10% Rh gauzes, foam monoliths, and extruded monoliths. The gauze catalysts were 40 mesh (40 wires per inch) or 80 mesh R-10% Rh woven wire samples which were cut into 18 mm diameter circles and stacked together to form a single gauze pack 1 to 10 layers thick. Gauze catalysts are used industrially in the oxidation of hftls to NO for HNO3 production and in the synthesis of HCN from NH3, CH4, and air. 

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