Abstract: Provided are a filter pack capable of suitably maintaining a space between pleats while suppressing an increase in pressure loss, and an air filter provided with the same. The filter pack includes a filter medium that collects fine particles in a gas and has multiple pairs of ventilation surfaces which are continuous and face each other through alternating folds due to pleating, and a space holding member that holds a space between each of the pairs of ventilation surfaces, and that is formed extending in a direction orthogonal to the fold on at least one of the pair of ventilation surfaces and has a base material layer and at least one space forming layer formed on the base material layer.

Abstract: An air filter includes: a pleated filter material folded into a zig-zag form at folding lines along a first direction to have peak parts and valley parts arising alternately in a second direction perpendicular to the first direction, trapping fine particles in a gaseous matter flowing in a gas flow direction perpendicular to the first direction and the second direction; a filter frame being a rectangular filter frame including one pair of first frame materials facing each other in the second direction having end parts in the first direction, and one pair of second frame materials facing each other in the first direction having end parts in the second direction, opening in the gas flow direction and housing the pleated filter material, each of the first frame materials and each of the second frame materials being combined to provide an overlap part.

Abstract: An air filter unit has a pleated filter medium with a zigzag shape in which a fibrous filter medium has been folded multiple times. The coefficients of linear expansion of the space-supporting members provided in each of the multiple folded spaces of the pleated filter medium are equal to or greater than the coefficient of linear expansion of the metal filter frame of the filter unit. The linear expansion coefficients of first space-supporting members are smaller than the linear expansion coefficient of a second space-supporting member. The first space-supporting members are provided in side portion regions including both side portions positioned at outermost sides of the pleated filter medium in a second direction perpendicular to the first direction. The second space-supporting member is provided in a central portion region sandwiched between the side portion regions.

Abstract: The invention provides a filter pack of which the mass is not increased, and moreover, the effective filter medium area is not reduced, and of which the pressure drop is sufficiently low, and the strength is sufficiently high, and an air filter using this. A pleated air filter pack is configured in such a way that dot embossed projections are provided on front and rear surfaces of a filter medium made of a non-woven fabric, the filter medium is folded in zigzag shape along creases of pleats, and the opposing embossed projections are brought into contact with each other when the filter medium is folded, thus maintaining the intervals between the filter media.

Abstract: Provided is a double-pleated air filter where filter elements each of which ensures an inter-pleat gap (air passage) by folding filter media in multiple layers and by defining a pitch, a thickness and a folding shape of the filter media are arranged in the V-bank-shaped structure whereby the air filter can be used with a large air volume due to a low pressure drop.

Abstract: The invention provides a filter pack of which the mass is not increased, and moreover, the effective filter medium area is not reduced, and of which the pressure drop is sufficiently low, and the strength is sufficiently high, and an air filter using this. A pleated air filter pack is configured in such a way that dot embossed projections are provided on front and rear surfaces of a filter medium made of a non-woven fabric, the filter medium is folded in zigzag shape along creases of pleats, and the opposing embossed projections are brought into contact with each other when the filter medium is folded, thus maintaining the intervals between the filter media.

Abstract: An air filter comprising a filter pack comprising a folded nanofiber filter medium, fitted to a filter frame through a seal material, the nanofiber filter medium being a filter medium for an air filter, comprising a nanofiber filter medium which, when a filter medium face velocity is 5.3 cm/s, has a performance index of collecting target particle diameter of 0.3 ?m, 0.040 (1/Pa) or more, performance index of collecting target particle diameter of 0.1 ?m, 0.030 (1/Pa) or more, and performance index of collecting target particle diameter of 0.05 ?m, 0.050 (1/Pa) or more. By this, a high air volume and low pressure drop type high-performance air filter using a nanofiber filter medium can be provided.

Abstract: A high-performance filter for an intake air for a gas turbine according to the present invention includes a low-efficiency filter media and a high-efficiency filter media superposed closely on each other in the named order from an upstream side in a direction of an air flow. Each of the filter media is formed with a filtering area of 20 to 35 m2. The filter media having a filtration efficiency of 40 to 70% for particles having a particle size of 0.3 &mgr;m is disposed as a layer upstream in the air flow direction, and the filter media having a filtration efficiency of 90 to 99.99% for particles having a particle size of 0.3 &mgr;m is disposed as a downstream layer. In addition, a filter unit according to the present invention is made using the above filter, Thus, even when the filter unit is used for atmospheric dusts including a high concentration of dusts having a particle size of 0.3 to 0.