From Filter Presses
Due to its excellent filtration results, the membrane filter press has proven itself in a number of applications, e.g. in mining, chemical or pharmaceutical industries. In order to meet the different requirements of industry and municipalities, MSE membrane filter presses are designed in modular design analogous to chamber filter presses. The solid and heavy-duty steel filter press frame, which consists of the following main components, forms the basis: Feeding stands with filtrate outlet (head piece), hydraulic stands with locking cylinder (pressure piece), cross beam and side rails on which the individual membrane filter plates are arranged including filter cloths.
The plate package consists of uniform membrane plates (optionally a mix of chamber membrane filter plates is also possible) with a cutout of 15-50 mm to accommodate the puncture-proof filter cake. The standard membrane material used is polypropylene (PP), synthetic rubber (e.g. NBR, EPDM) or thermoplastic elastomer (TPE). Special materials such as PVDF are also available. Membrane filter presses have a great influence on the dryness of the solid by using membrane technology in the filter plates. Compared to conventional filtration processes, it achieves the lowest residual moisture values in the filter cake. This makes the membrane filter press a powerful and the most widely used system.
Membrane Technology As A Solution – If Time And Degree Of Dewatering Are Crucial
Depending on the degree of dewatering, different dry matter contents (dry matter content – percentage by weight of dry material in the filter cake) can be achieved in the filter cake by squeezing with membrane plates. The range of achievable dry matter contents extends from 30 to over 80 percent. In the standard version, squeezing is carried out on both sides. Depending on the medium to be filtered, there is the option of only using membrane technology for every second filter plate. The combination of membrane filter plates and chamber filter plates (mixed package) reduces the initial costs and also guarantees excellent filtration results. This type of filter press is called the chamber membrane filter press.
Membrane filter presses not only offer the advantage of an extremely high degree of dewatering; they also reduce the filtration cycle time by more than 50 percent on average, depending on the suspension. This results in faster cycle and turnaround times, which lead to an increase in productivity. Even with partially filled filter chambers, excellent dry matter results can be achieved thanks to membrane technologies. This even applies with abrasive media, for example, pump wear is decreased by reduced feeding pressure (6-8 bar depending on the suspension) without affecting the final result. In order to ensure maximum protection of the membrane filter press, special safety systems are used for the various membrane inflation media. The membrane inflation medium consists either of compressed air or a liquid medium (e.g. water). As standard, squeezing pressures of up to 15 bar are possible and in special cases, these can be higher. Further information on squeezing with membrane technology can be found here.
A membrane filter press is fed in the same way as a chamber filter press, however the filling level of the chambers can be controlled manually. The increasing feed pressure ensures pre-compression and dewatering of the filter cake in the chamber. As soon as the feed pressure has reached the predetermined value (approx. 6-8 bar), the filter cake is squeezed again accordingly. The flexible membranes (e.g. filled with compressed air or water) press the filter cake solid onto the entire surface of the chambers. This compresses and thus expels free water over the filter cloth.
In order to achieve an even higher filtration quality, a membrane filter press has further configuration options to choose from. These include, for example, filter cake washing, filter cake dry blowing, core rinsing and core blowing. During filter cake washing, however, the filter cake must be pre-pressed. This stabilises the filter cake and thus prevents shrinkage cracks. After completion of the filtration process, the chambers are emptied. The closing pressure of the filter press is released, the filter press is opened and the cake is removed from the filter cloths. The filtration cycle is then repeated.
- Maximum degree of dry matter in the filter cake even with partially filled filter chambers
- Simple and economical filtration due to high degree of dewatering and shorter cycle times
- Compact and robust design
- Maximum versatility through expansion modules and automation options
- High level of security through the use of the latest security technology
- Reduced pump wear on abrasive media due to low feed pressure