A particulate filter disclosed herein includes a wall-flow structure substrate 10 and a wash coat layer 20 held inside a partition 16 of the substrate 10. The wash coat layer 20 includes an inlet layer 22 formed to have predetermined length L.sub.A and thickness T.sub.A from near an end thereof on an exhaust gas inflow side X1, and an outlet layer 24 formed to have predetermined length L.sub.B and thickness T.sub.B from near an end thereof on an exhaust gas outflow side X2. The inlet layer 22 and the outlet layer 24 partially overlap each other. In the particulate filter disclosed herein, the inlet layer 22 contains a precious metal catalyst, while the outlet layer 24 contains substantially no precious metal catalyst. The length L.sub.A of the inlet layer is 50% or more and 75% or less of a total length L of the partition 16. Thus, the particulate filter is capable of achieving both PM collection performance and pressure-drop reduction performance at high levels.

An apparatus and methods to eliminate PFAS from wastewater biosolids through fluidized bed gasification. The gasifier decomposes the PFAS in the biosolids at temperatures of 900-1800° F. Synthesis gas (syngas) exits the gasifier which is coupled to a thermal oxidizer and is combusted at temperatures of 1600-2600° F. This decomposes PFAS in the syngas and creates flue gas. Heat can be recovered from the flue gas by cooling the flue gas to temperatures of 400-1200° F. in a heat exchanger that is coupled with the thermal oxidizer. Cooled flue gas is mixed with hydrated lime, enhancing PFAS decomposition, with the spent lime filtered from the cooled flue gas using a filter system that may incorporate catalyst impregnated filter elements. The apparatus and methods thereby eliminate PFAS from wastewater biosolids and control emissions in the resulting flue gas.

An apparatus and methods to eliminate PFAS from wastewater biosolids through fluidized bed gasification. The gasifier decomposes the PFAS in the biosolids at temperatures of 900-1800° F. Synthesis gas (syngas) exits the gasifier which is coupled to a thermal oxidizer and is combusted at temperatures of 1600-2600° F. This decomposes PFAS in the syngas and creates flue gas. Heat can be recovered from the flue gas by cooling the flue gas to temperatures of 400-1200° F. in a heat exchanger that is coupled with the thermal oxidizer. Cooled flue gas is mixed with hydrated lime, enhancing PFAS decomposition, with the spent lime filtered from the cooled flue gas using a filter system that may incorporate catalyst impregnated filter elements. The apparatus and methods thereby eliminate PFAS from wastewater biosolids and control emissions in the resulting flue gas.

An automatic regeneration controller for a particular filter comprises an engine controller, a unit controller, and a load application cancellation switch. With filter regeneration being started by determination of particulate accumulation and with an idling or light-load operation being conducted, load request to a work unit is outputted from the engine controller to the unit controller. Then, when load application is not possible or the load application cancellation switch is on and, in addition, exhaust temperature is not maintainable with no load application, a regeneration stop signal is outputted from the unit controller to the engine controller and a regeneration stop signal reception process is conducted in the engine controller, and with no forced load application to a hydraulic unit, fuel addition is stopped to stop automatic regeneration control.

According to an embodiment of the present application, there may be provided an air purification apparatus for purifying polluted air and discharging the purified air, which comprises a main pipe including a first flow path, a second flow path, a first filter, a first main area, and a second main area. The air purification apparatus can operate in a filtering mode in which at least some contaminants contained in the air flowing into the main pipe are collected by the first filter, or a cleaning mode in which at least some of the contaminants collected by the first filter in the filtering mode are removed, wherein an operation section in the cleaning mode of the air purification apparatus includes a firs section and a second section, the first section and the second section are divided on the basis of a first division time point, and the rate of change of temperature in the first main area is varied before and after the first division time point.

According to an embodiment of the present application, there may be provided an air purification apparatus for purifying polluted air and discharging the purified air, which comprises a main pipe including a first flow path, a second flow path, a first filter, a first main area, and a second main area. The air purification apparatus can operate in a filtering mode in which at least some contaminants contained in the air flowing into the main pipe are collected by the first filter, or a cleaning mode in which at least some of the contaminants collected by the first filter in the filtering mode are removed, wherein an operation section in the cleaning mode of the air purification apparatus includes a firs section and a second section, the first section and the second section are divided on the basis of a first division time point, and the rate of change of temperature in the first main area is varied before and after the first division time point.

In a honeycomb structure, porous partition walls are arranged to surround cells extending from an inflow end face of the honeycomb structure body to an outflow end face thereof, intersection points at which the partition walls arranged in a latticed manner in the inflow end face intersect include a first intersection point that is one intersection point, and second intersection points one of which is the other intersection point in the partition wall including the first intersection point, and which are adjacent to the first intersection point, and the inflow end face has concave/convex portions each including the first intersection point as a bottom portion and the peripheral second intersection points of the first intersection point as top portions, or each including the first intersection point as a top portion and the peripheral second intersection points of the first intersection point as bottom portions.

A honeycomb filter includes a pillar-shaped honeycomb substrate including a porous partition wall that defines a plurality of cells extending from an inflow end face to an outflow end face, an inflow side plugging portion disposed at the inflow end face of the honeycomb substrate to plug open ends of outflow cells and an outflow side plugging portion disposed at the outflow end face of the honeycomb substrate to plug open ends of inflow cells other than the outflow cells. The honeycomb substrate includes the partition wall that defines two of the inflow cells by division. An average of the plugging length L.sub.IN of the inflow side plugging portions disposed in the outflow cells of the honeycomb substrate is larger than an average of the plugging length L.sub.OUT of the outflow side plugging portions disposed in the inflow cells of the honeycomb substrate.

An aftertreatment system comprises a SCR system, a first filter, and a second filter disposed downstream of the first filter and a bypass conduit providing a flow path bypassing the second filter. A valve is operatively coupled to the bypass conduit and is moveable between a closed position in which the exhaust gas flows through the second filter, and an open position in which at least a portion of the exhaust gas flows through the bypass conduit. A controller is operatively coupled to the valve configured to adjust the valve based on a first filtration efficiency of the first filter to cause the exhaust gas expelled into the environment from the aftertreatment to have a particulate matter count meeting particulate matter emission standards.

The invention relates to a method for replacing an exhaust aftertreatment component of an exhaust aftertreatment system in a vehicle or vessel. The exhaust aftertreatment system is delimited by an outer casing and comprises a first sleeve, which extends in an axial direction and contains a first exhaust aftertreatment component mounted directly in the first sleeve. The method comprises the steps of: removing the first exhaust aftertreatment component from the first sleeve, the first sleeve thereby remaining intact within the outer casing, providing a second exhaust aftertreatment component being mounted in a second sleeve, the second sleeve being configured to fit within the first sleeve, and mounting the second sleeve with the second exhaust aftertreatment component in the first sleeve by inserting the second sleeve into the first sleeve in the axial direction thereof.