This paper analyzes the screening principle of banana screen, summarizes the development status of banana screen at home and abroad in recent years, and compares and analyzes the differences of banana screen at home and abroad in design concept and design method, selection of technical parameters, design of key parts, anti-corrosion, anti-wear treatment, power consumption of equipment, vibration and noise control.
Banana screen (also known as equal thickness screen), combining the advantages of linear motion screen and circular motion screen, first appeared in Germany, Australia, South Africa and other countries, in the late 1970s for the first time in the coal preparation plant and mining plant since the use of screening equipment enterprises and scientific research units at home and abroad have developed two types of single and double screening surface banana screen, It has been widely popularized and applied in various processes such as classification, desliming, desliming and dehydration in coal preparation plant.
The basic principles of various banana sieving at home and abroad are similar, mainly based on the equal thickness screening method proposed by French E. Burstrein in 1965, and its basic principle is: With the Angle of the banana screen surface, it is slowly reduced in stages. Due to the sifting effect of the sifting material on the sifting surface, the sifting material is gradually reduced, and the movement speed of the material is gradually slow, so that the material on the sifting surface of the banana screen basically maintains the same sifting thickness during the whole sifting process. At present, the screen surface is generally divided into 3, 5 and 6 angles according to the use of the traditional experience that: 6 angles are more suitable for desliming, desliming and dehydration operations, while 3 angles and 5 angles are suitable for grading operations. 2. Development status of banana screen at home and abroad
(1) The development status of foreign banana screens
At present, some foreign countries in the development of banana screen in the world's leading position, and in the world market, Schenck banana screen is the fastest growing, accounting for about 70% of the market share.
Banana linear vibrating screen is mainly divided into two series: single screen SLO series and double screen SLD, the current specifications of the maximum length 9.15m, 4.3m wide. Compared with the traditional screening machine, the stress effect is reduced by more than 25%, the overall weight is more than 40% lighter, and the motor power used is reduced by more than 15%. At present, the 4.27mx7.32m banana screen has been developed, and the banana screen is mainly divided into single layer and double layer banana screen. banana screen under the same efficiency, the processing capacity is 20% higher than other similar banana screen products, the use efficiency is 90% to 95%, and its specifications reach a maximum length of 9.15m and a width of 4.27m. Jbanana screen in recent years has continued to open up foreign markets, rapid development, the maximum effective screening area of 9.15m long, 4.2m wide. Banana screen is mainly divided into two kinds: multi-angle (MF) vibrating screen and multi-angle (MS) vibrating screen, respectively using thin oil lubrication and dry oil lubrication, the current series of banana screen maximum specifications of 8.5m long, 3.6m wide.
(2) The development status of domestic banana screen
In 1977, the technology of equal thickness screening was applied to coal screening in China, and the technological parameters of equal thickness screening were explored through a large number of industrial experiments. Since 1995, due to the continuous increase of the scale of coal preparation plants in China, especially with the large-scale promotion and application of heavy medium coal preparation technology in China, banana screen has been more and more widely favored and welcomed with its advantages of large processing capacity, high efficiency and reliable performance.
At present, a large number of domestic banana screen development and production enterprises, they keep up with the growing market demand, adapt to the rapid development of banana screen technology situation, while advanced to foreign countries
The continuous digestion and absorption of similar banana screen products developed by enterprises, and independent innovation, has studied various models of banana screen products, such as: ZXF (T) series, TXZ series, XBHS series, JR series and SXJ series banana screening, has been widely promoted and applied in domestic coal preparation plants and mining plants, gradually breaking the situation that our country mainly relies on foreign banana screening imports for a long time, and some have been exported to Ukraine, the United States, Poland, etc. In addition, in the past two years, Sino-foreign joint ventures have developed the fastest, such as the Sino-Australian joint venture to develop ABS banana sifters.
At present, the domestic banana screen structure mainly adopts the eccentric block way, relying on the mesh gear forced drive, producing reciprocating linear vibration power of opposite rotation, driving the banana screen sieve machine to do reciprocating harmonic vibration, the current domestic banana screen is mainly divided into single or double banana screen 2 kinds, the relevant data shows: The maximum screening surface reaches 39.56 square meters, the screening length is 9.2m, the width is 4.3m, the screening capacity is as high as 2500t/h, the work efficiency, product performance and screening area rank first in the world similar banana screening products, and the sales price is only about 38% of the foreign similar banana screen products. The development of this product breaks the situation that foreign banana screen enterprises monopolize large banana screen for a long time.