Multiple-deck Fine Screens From Haver & Boecker
Designed for the screening of fine loose materials, such as quartz sand, the Niagara M-Class multiple-deck screening machines from Haver & Boecker are an extension to the existing five screening systems offered by the company, who until now had been able to offer only a limited number of alternatives for the classification of dry materials into fine and very fine particle ranges.
Despite their minimal footprint, the M-Class multiple-deck screening machines offer a very large screening surface area. This has been achieved by stacking the screen decks horizontally, one over another, which at the same time constitutes the frame of the linear vibrating machine.
According to Haver & Boecker, a major advantage offered by the system is the highly accurate cut size achieved during screening. Another advantage of the modular design is the machine’s adaptability, eg to increase material throughput.
In addition, extremely long screen cloth life is characteristic of the M-Class screening machines. This is because the machines create minimal acceleration during screening, thereby keeping dynamic loadings to a minimum.
The Niagara M-Class multiple-deck screening machines are currently available in eight different sizes, with the number of decks and technical specifications varying to suit specific applications. Haver & Boecker say the machines will be further developed and optimized to ensure they continue to fulfil market requirements.
Haver success in dry mortar production
Sand processing plays a key role in the manufacture of premium-quality dry mortar, as a uniform particle size composition is essential for assuring the quality of the end product. Not surprisingly, therefore, the screening system is a major factor in this process and can prove decisive in terms of the quality and economic success of a plant.
For several years now a large dry mortar producer in Thailand has relied on Haver & Boecker’s expertise and experience in this particular field by equipping four dry mortar plants with Niagara vibrating screens. Recently, the customer opted to use this proven technology once again for their newest production facility in Kao Wong, in eastern Thailand.
The new 180 tonnes/h sand processing plant, which commenced operations in mid-September 2007, has a total of 10 Haver & Boecker machines making up three production lines. First, crushed limestone is fed to three identical and fully dust-encapsulated Niagara R-MTR 1400 x 7500 linear vibrating screens by three Haver UF 650 x 2315 vibrating feeders. The –12.5mm feed material is separated at 3.32mm, 1.6mm and 0.75mm, with the overflow from the first deck being recirculated for further crushing, while the throughput from the first and second decks fulfils the requirements for producing the dry mortar end product.
Material passing through the third deck of all three screens is distributed to two high-frequency screening machines, equipped with direct excited screen cloths, for further screening. The Fine-Line screening machines, which are characterized by their high performance, are double-deck units, each having a screening surface area of 22.5m2. Both machines deliver cut sizes of 0.53mm and 0.15mm. Constant and uniform material feed over the complete width of the high-frequency screens is accomplished using two specially designed Haver input channels.
