Abstract: A particulate trap that burns and removes particulate matters (particles, consisting mainly of carbon particles, contained in the exhaust gas of a diesel engine of a car) trapped by a filter without using a specifically provided heat source such as a burner or an electric heater even when the car is running in ordinary urban areas, i.e., when the exhaust gas is low in temperature. In the particulate trap, a catalytic converter 3, formed of a metallic porous body having a three-dimensional network structure, carrying an oxidizing catalyst is placed upstream of a filter 4 that traps particulate matters. The catalytic converter 3 oxidizes NO in the exhaust gas into NO2, which in turn burns and removes particulate matters trapped by the filter 4.

Abstract: An exhaust gas purifier which can efficiently eliminate particulate matter discharged from an engine, and which has a long life. The purifier is attached to a discharge passage of an engine, and includes a filter constituted by a plurality of cylindrical filter elements each formed of porous metal. The filter elements are different in diameter from each other, and disposed concentrically and assembled radially apart from each other through a space. The filter has an exhaust gas inlet passage side end and an exhaust gas outlet passage side end, the exhaust gas inlet side end being closed, by a shielding plate, up to the cylindrical filter element of the largest outer diameter, and the exhaust gas outlet passage side end being closed at a portion between an outer circumferential case and the cylindrical filter element of the smallest outer diameter.

Abstract: A meshed plate-like heater is disposed between multi-layer cylindrical filters without contacting with the filters to constitute a DPF. The heater has a form in which strip-like electric conduction paths are arranged and developed side by side horizontally, and then made cylindrical such that the different electric resistances are set for the inlet portion, the outlet portion and the center portion so as to constitute a DPF for regenerating particulates. The regenerative heater realizes a uniform temperature distribution all over the regenerative heater within a range of from about 600.degree. C. which is the self-burning temperature of the particulates to 1,000.degree. C. which is the heat-resistance temperature of the filters, in 10 minutes after the start of regeneration.

Abstract: Thin plate-like electric heaters are disposed among multi-layer cylindrical filters for capturing particulates in positions without contacting with the filters. As the means for more reducing the power supply to the heater as the position of the heater is closer to the central cylinder of the multi-layer filters, the thicknesses of the thin plate-like electric heaters or the geometrical patterns of the electric conduction paths are changed to thereby set the resistance values of the heaters in advance in order to reduce the temperature of the central-side cylinder which is apt to be high to thereby realize the balance with the temperature of the outer-circumferential cylinder, or the electric conduction quantity to the heaters is selectively more reduced as the position of the heater is closer to the central cylinder to realize the balance of temperature distribution with the filter on the outer-circumferential side filter.

Abstract: An object of the invention is to provide a high quality synthetic diamond having a high bonding strength between a substrate surface and synthetic diamond or between synthetic diamond films. The object can be attained by a process for the synthesis of diamond comprising pre-heating mixed gases of a hydrocarbon and hydrogen by a heating body and feeding the heated mixed gases to a substrate surface heated to deposit diamond thereon, characterized by allowing the distance between the heating body and substrate surface to be apart from each other as far as possible in the carburizing step of the heating body and allowing the distance between the heating body and substrate surface to be nearer in the step of synthesizing diamond than in the former case.