EXHAUST GAS PURIFYING APPARATUS, EXHAUST GAS PURIFYING METHOD, AND PARTICULATE MATTER MEASURING METHOD

摘要

An exhaust gas purifying apparatus comprising a diesel particulate filter(DPF) is provided to be used in order to remove particulate matter(PM) contained in exhaust gases of diesel engines, an exhaust gas purifying method using the exhaust gas purifying apparatus is provided, and a particulate matter measuring method for particulate matter(PM) contained in the exhaust gases of the diesel engines is provided. An exhaust gas purifying apparatus comprises: a primary diesel particulate filter(22) installed in an exhaust line(21) of a diesel engine; a secondary exhaust line(21A) branched off from the exhaust line at an upstream side of the primary diesel particulate filter; a secondary diesel particulate filter(22A) which is installed in the secondary exhaust line, and has a smoke storage capacity smaller than that of the primary diesel particulate filter; and a differential pressure measuring part(22B) for measuring a differential pressure(DeltaP) between an inlet and an outlet of the secondary diesel particulate filter. The secondary exhaust line additionally includes a flow meter(24) or an equivalent meter. The secondary exhaust line additionally includes a temperature measuring part(T1). The secondary diesel particulate filter additionally includes a heater. The exhaust gas purifying apparatus further comprises a valve(23) for maintaining a flow rate of the exhaust gas at a predetermined value in the secondary exhaust line.