German company BWF Envirotec is adding the PM-Tec membrane product line to its product portfolio. The new PM-Tec product line is a high performance filter medium for industrial filtration. Fine airborne dust is detrimental to human health to a considerable extent. Fine dust contamination is particularly high in conurbations and industrial zones. Primary fine dusts particularly occur during industrial combustion processes such as for instance in waste incineration plants, cement works or power plants or also in the metalworking industry. By using effective filter media to combat all types of dust, industrial filtration makes a valuable contribution to keeping the air clean. BWF Envirotec has been producing filter media for industrial filtration for over 40 years. The company says that it is now extending the product portfolio with the new PM-Tec product line and is offering new filter media specifically for use in the filtration of minute dust particles - particulate matter. The term particulate matter was introduced at the end of the 1980s by the US environment protection authority, the EPA (Environmental Protection Agency), which defined the PM standard as a classification in the measurement of fine dust. This fine dust categorisation is now used internationally for the classification of fine dust. In the new PM-Tec product line BWF Envirotec combines a good carrier media consisting of needlona® needle felt or fibreglass fabric with a high-efficiency ePTFE membrane. Production is through a continuous in-house process chain, starting with the manufacture of needlona® filter media, including the laminating process, to finishing of the complete filter bags.
Low emissions
BWF Envirotec adds that the product line consists of a carrier medium on which an ePTFE membrane is laminated. The membrane produced from polytetrafluorethylene possesses characteristics which are optimally suited for use in industrial fine dust filtration. Dust on the raw gas side impinges on the filter medium and is retained on the surface and cannot penetrate into the carrier medium. Owing to the smooth and anti-adhesive surface, the particles do not embed themselves in the carrier medium but accumulate on the surface of the filter medium instead. They are then almost completely cleaned away during the dedusting process in the filtration system. The characteristics of the individual components of the new PM-Tec product line include a membrane structure that is characterised by optimum orientation and fineness of the fibrils, in addition to a uniform pore size. A low surface tension, which reduces the adhesion of fine dust, as well as a temperature resistance of up to 288°C ensures optimum filtration properties, the company adds. In-line quality controls and constant air permeability monitoring during production have also been added during the laminating process. According to BWF Envirotec, the membrane-compatible presentation of the filter media during the entire production process helps to ensure maximum quality. The most demanding emission requirements can also be fulfilled by appropriate sewing and sealing technology during the manufacturing process. Further characteristics of the PM-Tec product line include extremely low and stable differential pressure behaviour, constant gas volumetric flow, long service life, low maintenance expenditure and good reliability, adds the company.
Carrier medium
The new PM-Tec product line for fine dust filtration is available with two different carrier media. Fibreglass fabric offers high temperature resistance and is therefore used as a carrier for the ePTFE membrane in many industrial applications. The prerequisite for many years of successful use is a moderate gas composition and low mechanical stress of the fibreglass fabric during operation, in addition to a specifically adapted pre-treatment of the fabric during manufacture. Under aggressive conditions of use, BWF Envirotec says that a carrier medium made of a customised needlona® needle felt can be selected that withstands the chemical and mechanical demands for a longer period than the fibreglass and therefore achieves longer service lives. BWF Envirotec supplies the new product line as material on a roll for manufacturers of filter bags, or as made-up filter bags for manufacturers or operators of industrial dedusting plants.
Applications
PM-Tec finds applications in all industrial dedusting plants where very fine dust occurs in the production or manufacturing process. For instance, in the cement industry, waste utilisation plants, power plants, in the chemical and pharmaceutical industry, as well as the metals or plastics processing industries. BWF Envirotec can determine which filter medium is suitable for a particular dedusting process. This will take into account the operation-specific characteristics of the filtration system and will put an emphasis on the most economical solution. The PM-Tec filter medium, whether made of fibreglass fabric or needlona® needle felt such as polyphenylene sulphide, polytetrafluorethylene or polyester, ensures low emissions in the filtration system.
