Abstract: The invention relates to a filter cloth intended for a filter which has a variable volume and is based on diaphragm extrusion, particularly for a Larox®-type vertical pressure filter. The filtering properties of the filter cloth (5) are substantially similar in both directions through the cloth since slurry containing liquid and solids is alternately placed on the different sides of the filter cloth. The filter cloth of the invention comprises a middle layer (15) and protective layers (16a, 16b; 17a, 17b) provided on both outer surfaces of the middle layer. The middle layer can have e.g. a woven structure, and the protective layers may be batt fiber layers attached to the middle layer by needling. According to a preferred embodiment of the invention, the protective layers according to the invention are denser than the middle layer.

Abstract: A solid-liquid filtration cloth comprising a base fabric woven from polymer yarns. After the weaving, the base fabric has been treated by a polymer material, which has better electric conductivity than the polymer yarns of the base fabric. The polymer treatment is carried out by means of a polyaniline solution or a polypyrrole solution, for instance. After the polymer treatment, at least the yarns on the surface of the base fabric comprise a coating of an electrically conductive polymer.

Abstract: A process for causing gaseous trace element particles to pass from a flowing hot gas into a fine particulate material by means of water. A mixture of the hot gas and water drops is caused to flow substantially upwards at such a velocity that the water drops remain in the gas flow and for a period long enough for most of the mass of the water drops to evaporate in order to cool the gas and to increase its relative humidity. After the gases have reached their wet temperature, they are brought into a turbulent state in order to cause the dust particles and the water drops which have decreased through evaporation to impinge against each other in order to produce in the aqueous film which covers the dust particles an exothermal ion reaction between the gaseous water-soluble trace element particles and the fine particles. Thereafter, the mixture is caused to flow further in order to evaporate the remaining water by means of the heat of reaction so that a dry end product is obtained.