Patent ID: 7822164

Claim:
A protective screen for screening off a suction space and a suction duct connected to it, in an emergency cooling system of a nuclear power plant, said protective screen including at least one screen wall element having a suction side and an outflow side, wherein the screen wall element is built up of one or more modular cassette units for screening off a suction space and a suction duct connected to it in an emergency cooling system of a nuclear power plant, wherein the cassette units have rectangular sides, wherein the cassette units each contain: a plurality of screen pockets formed into rows which are open towards the suction side and which extend between two opposed rectangular sides of the cassette, two elongated lateral walls which extend between said two opposed rectangular sides of the cassette and which form lateral sides of the cassette, each lateral wall being formed from perforated sheet metal, and one or more elongated intermediate walls arranged between the lateral walls and formed as double walls with the double walls being open towards the outflow side, each intermediate wall extending between said two opposed rectangular sides of the cassette and being formed from perforated sheet metal, with the lateral walls and the one or more intermediate walls forming the lateral sides of the screen pocket rows, wherein each screen pocket is formed from an elongate portion of perforated sheet metal that is bent into a longitudinal valley, said longitudinal valley being transverse to the elongated lateral walls and the one or more intermediate walls, and said bent, elongate portion of perforated sheet metal spanning the distance between two consecutive intermediate walls or between one of the elongated lateral walls and an adjacent intermediate wall, with the screen pocket being open towards the suction side over said distance, and each screen pocket row has outflow gaps between said valleys on the outflow side, said outflow gaps being connected to the outflow side or open toward the outflow side, and wherein the cassette units are modularly configurable for placement in a row in order to assemble the screen wall element in the desired size.