Apparatus and plants for ventilating, heating, cooling, drying, humidifying, dehumidifying, hardening, cooking, lighting in connection with treatment of air by heating, cooling humidifying, dehumidifying, cleaning, including cleaning in electrical way, heat and/or moisture exchange, heat exchangers for air and/or other gaseous media, warm air furnaces, air filters, wet cleaning aggregates for air and/or other gaseous media, ventilators, centrifugal separators such as apparatus for separating dust from air or other gases; air supply grilles, exhaust valves and registers for used air, dampers, for ventilating plants; ducts and channels for ventilating plants; dryers and conditioning plants for drying or moistening, demoistening, hardening, for treating cellulose and other fibrous materials, paper, cardboard, carton, disintegrated cellulose, grain, lumber, veneer and board

Apparatus and plants for ventilating, heating, cooling, drying, humidifying, dehumidifying, hardening, cooking, lighting, in connection with treatment of air by heating, cooling, humidfying, cleaning, including cleaning in electrical way, heat and/or moisture exchange, heat exchangers for air and/or other gasaous media, warm air furnaces, air filters, wet cleaning aggregate for air and/or other gaseous media, lang, centrifugal separators, exhaust valves and registers for used air, dampers for ventilating plants, dryers and conditioning plants and other fibrous materials, paper, cardboard, carton, disintergrated cellulose, grain, lumber, veneer and board.