1、2012 届 华北科技学院 本 科 毕 业 设 计 外 文 翻 译 翻 译 题 目： Hydrocyclone in the coal cleaning applications 姓 名： 丁清珍 学 号： 200801024105 专业班级： 矿物 B081 院 部： 环境工程学院 指导教师： 张秀梅 2012 年 6 月 20 日 Hydrocyclone in the coal cleaning applications TABLE 7-14. Effect of Geometry and Concentration of Feed Solids on throughput for a
2、1/6-in, diam hydro cyclone cleaning 1/4-in Varying the distance between the bottom of the vortex finder and the hydro cyclone cone bottom. For example, the washed coal ash can be reduced by decreasing the diameter of the vortex finder, decreasing the length of the vortex finder, or increasing the di
3、ameter of the underflow orifice. Increasing feed-Solids content increases the specific gravity of separation and, therefore, washed coal yield and ash, which indicates the importance of maintaining a constant feed-solids content to preserve washed coal quality. Capacity is influenced by cyclone geom
4、etry, i.e., the sizes of the overflow, underflow, and inlet openings, and by feed-solids content. The effects of these parameters is given in Table 7- 14.Increasing inlet pressure is a simple method of increasing capacity without changing hydro cyclone geometry, and washed yield and ash are not sign
5、ificantly affected. However, the penalty is increased pumping cost, and degradation of the coal. Flow sheets Soon after the hydro cyclone was developed, it became evident that performance was inferior to nearly all other cleaning devices. Consequently, in an effort to improve performance, three two
6、stage circuits, shown in Fig. 764, were developed. In the earliest two-stage circuit, called two-stage relearn or TSR, the refuse from a primary hydro cyclone is simply relearned in a secondary hydro cyclone, The overflows from the two hydro cyclones are recombined as the washed coal product, and th
7、e underflows from the secondary hydro clone contains the final refuse. In more recent installations, one of the products from the secondary hydro cyclone is recirculated to the feed of the primary hydro cyclone. In the two-stage overflow recirculation circuit, TSOR, the primary or first-stage hydro cyclone is adjusted to produce an acceptable
