圆振动筛设计的外文翻译(编辑修改稿)

圆振动筛设计的外文翻译(编辑修改稿)内容摘要：

warm, dry screen wire versus cold, damp material can be maintained economically through transformer control settings. With every opening in the heated screen mesh protected against blinding, there is no guesswork about what size particle will be delivered. A uniform, unvarying quality to meet tough specifications es through day after day, no matter what the weather. (High humidity makes trouble with unheated screens.) Plants operating heated screens will have no trouble with excessive amounts of fine, dusty material that formerly sifted through reduced meshes on clogged screens. Service life of screen cloth is greatly increased when electric heating ends the punishment of oldfashioned cleaning methods, such as rough pounding or brushing. Blowtorch flames put too much heat in one spot and bouncing chains added to wear and tear. But, screens kept clean and open with electric heating reportedly are seldom mistreated and last up to eight times as long. Heated decks end the threat of pile ups and strains that can break the mesh. Economical operation of electric heating for screens requires one transformer for installations of up to three panels of screen cloth (maximum area 4 x 12ft). Two transformers are used on longer decks. Any deck (top, center or bottom) can be heated. Electric heating is most desirable of all where a screen surface is hard to get at. Changing heated screens does not involve more unbolting than needed for ordinary screens. In specifying screens to deliver a uniform particle through heated mesh, the first thing to consider is weight per square foot of the wire cloth needed to set up appropriate resistance. Most calculations are based on square openings. Slotted openings must be identified as to width of clear opening, diameter of wire and number of wires per inch before weight per square foot can be found in any screen cloth manufacturer39。 s catalog. Having determined the usable weight per square foot of screen cloth, the next step is to select the size of clear opening needed, making no allowance for reduction in this size as formerly was the case when material stuck to the wires. Heated wires will maintain the clear opening at all times, making it possible to screen finer without blinding. From a wire catalog, select a mesh weighing no more per square foot (can weigh less) than determined using the method above with the clear opening characteristics desired. This often turns out to be a more efficient screen because the wire diameter will be smaller and the percentage of the open area will be greater. For example, where a 1/8in. clear opening was desired (but often blinded) on unheated screens, the wire diameter was and the open area was 44 percent. The cloth weighed lb/ft. 2. For a heated 3 x 12ft sc。