Abstract: A multi-stage variable type waste heat storage and recovery apparatus and method thereof are disclosed. The apparatus includes a phase change material storage unit for separating and arranging a plurality of phase change materials having different melting points, and arranging them in stages on a path of the waste heat so that a phase change material having a higher melting point is located closer to an inlet side of the waste heat; a use place registration unit; a temperature range storage unit; a phase change material selection unit for selecting a phase change material of a corresponding melting point; and a heat energy supply unit for supplying heat energy by the latent heat of the phase change material selected by the phase change material selection unit to a corresponding heat energy use place among a plurality of heat energy use places.

Abstract: A nitrogen oxide reduction type regenerative thermal oxidation system and a method for nitrogen oxide reduction thereof are disclosed. The nitrogen oxide reduction type regenerative thermal oxidation system according to the present invention is characterized by comprising: a first reduction device for primarily reducing nitrogen oxides generated by a regenerative thermal oxidation device based on a selective non-catalytic reduction method; an exhaust gas storage device for storing the exhaust gas being discharged from the regenerative thermal oxidation device; a second reduction device for secondarily reducing nitrogen oxides based on a selective catalytic reduction method for an exhaust gas stored in the exhaust gas storage device; and a suction and discharge device for sucking in the exhaust gas with secondarily reduced nitrogen oxides from the exhaust gas storage device and discharging it into the atmosphere.

Abstract: A multi-plate scrubber is provided, and more particularly, a multi-plate scrubber including plates having different shapes to purify polluting gas is provided. According to the multi-plate scrubber, the polluting gas is effectively purified by increasing chances of contact between the polluting gas and circulating water by using various plates having different shapes.

Abstract: A regenerative thermal oxidizer purifies a polluted gas by oxidizing a volatile organic compound (VOC) contained in the polluted gas at a high temperature by using an amount of heat of the polluted gas.