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The pore diameter and porosity of SiC-DPF has been increased by elaborating its porous structure. Increasing the porosity of DPF decreases its strength and thermal conductivity. It was clarified how these characteristics affect the performance such as filtration characteristics, low pressure loss, maximum soot loading limit, and thermal response characteristics required for DPF. It was found that the basic characteristics of SiC such as high strength and high thermal conductivity play an important role in its high porosity.

One technology for removing PM discharged from diesel-powered vehicles is the DPF system. The DPF system brings about increases in pressure loss because PM accumulates in the filter. DPF with a high cell density shows low pressure loss when PM accumulates because of the large filtration area, and in addition, it makes it possible to thin the cell wall because it has a high thermal diffusion ability. For the catalyzation of SiC, the pore size and porosity of the base material were changed. Even when a catalyst is borne, pressure loss which DPF changed pore structure hardly changes. This verification was done based on the theory and by means of experimentation.

In Europe, where diesel engine cars enjoy widely popularity, the major diesel-engine car manufacturers have already announced that they will equip their diesel engine vehicles with DPF systems. Silicon carbide(SiC) has good fundamental properties. And the crack problem during regeneration could be successfully controlled by using split-type DPF which consists of multiple filter segments. The functional characteristics were focused on. For DPF, a model test by which events that may actually occur on vehicles can be produced is said to have not yet been established. From this point of view, in this study, SiC-DPF functions are characterized and evaluated under a regeneration system, and their correlation is discussed.

A heater type automatic regeneration system able to be mounted on an automobile has been developed by utilizing the characteristics of SiC-DPF (Diesel Particulate Filters made of Silicon Carbide). In this development, in order to apply the system to wide applications, the main objective was to focus on reducing the regenerating electric power consumption. For the reduction of the power consumption, realization of a low pressure drop system effect by making the DPF structure high density and improvement of the axial insulation, controlling the gas flow velocity by a general purpose exhaust brake, saving of the electric power by using a DC heater driver utilizing MOSFETs (Metal Oxide semi-conductor field-effect transistor). As a result, a SiC-DPF heater unit usable in wide range of applications has successfully been developed.