The grinding machine is used in combination with a classifier to form a grinding and grading process. A large piece of ore is ground to the desired fineness, generally in stages, with each section only completing a portion of the entire grinding process, which is referred to as the grinding section. Modern multi-application beneficiation plant in paragraph or two grinding process, rarely used more than three-stage grinding process. The number of grinding sections is mainly determined by the size of the mine, the grindability of the ore, the size of the useful mineral crystal grain, the size of the ore and the particle size of the final product. In general, when the upper limit of the final product particle size is greater than 0.15 mm, a one-stage grinding process can be used; when the final product particle size upper limit is less than 0.15 mm, a two-stage grinding process should be used. The number of suitable grinding processes should be determined according to the specific circumstances and after technical and economic comparison.
There are many forms of grinding grading, but the most basic ones are shown below.
Figure a, an inspection period of closed-circuit grinding classification process, applicable to the case of rough grinding the grinding fineness greater than 0.15 mm, are widely used in the concentrator of gold.
Figure b shows a closed-circuit grinding process with inspection grading and controlled grading. Suitable for small concentrators, in order to simplify the grinding process, the grinding fineness can be used when the fineness is not less than 0.15 mm. This process can reduce over-grinding.
As shown in Figure c, there are two sections of closed-circuit grinding process for inspection and classification, which are suitable for use in ore dressing plants with large grain size and large production scale. In the first section, a common rod mill is used for open grinding, and the ore of 20 to 25 mm is ground to about 3 mm and then finely ground by a ball mill .
Figure d shows the two-stage two closed-circuit grinding process, and the pre-grading and inspection grading of the second-stage grinding are combined. It is commonly used in large and medium-sized concentrators where the final product size is less than 0.15 mm. This process must correctly distribute the load of the first and second stages of the mill to improve the grinding efficiency.
The finned tube is to improve the heat exchange efficiency. By adding fins on the surface of the heat exchange tube, the outer surface area (or inner surface area) of the heat exchange tube is increased, so as to achieve the purpose of improving the heat exchange efficiency. Such a heat exchange tube . Usually used for heat exchange between liquid and gas.
Finned tube is a heat exchange element. As a heat exchange element, finned tubes usually work under high-temperature flue gas conditions for a long time. For example, the finned tubes usually used in boiler or harsh environments, high temperature and high pressure, and in a corrosive atmosphere. This requires that the finned tubes should have high anti-corrosion properties, Anti-wear properties, lower contact resistance, higher Stability and anti-dusting ability.
There are many types of finned tubes, and new varieties are constantly emerging. According to the classification of processing technology, there are extruded fin tube; high frequency welded finned tubes; rolled formed finned tubes; suit formed finned tubes ; cast finned tubes; tension wound finned tubes; Inserted tubes.
According to the shape of the fins, there are square finned tubes; circular finned tubes; spiral finned tubes; longitudinal finned tubes; corrugated finned tubes; spiral serrated fins Helical Serrated Finned Tubes; pin-shaped finned tubes; integral plate-shaped finned tubes; inner finned tubes.
According to whether the fin material of the finned tube is the same as that of the base tube, it can be divided into: single metal finned tube, bimetallic composite finned tube.
Single metal finned tubes are classified by material into copper finned tubes; aluminum finned tubes; carbon steel finned tubes; stainless steel finned tubes; cast steel finned tubes.
Finned Tube,Extruded Fin,Brown Fin Tube,Longitudinal Finned Tube
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