Provided is an adsorption filter structure, and more specifically, an adsorption filter structure with easy detachment and increased filter efficiency. The adsorption filter structure includes a filtration unit passing external air through an internal space in a filtration direction, and filtering the external air, an external vent and an internal vent, and the helmet to which the adsorption filter structure is applied includes a protection unit into which the adsorption filter structure is interpolated and the external air entrance hole is formed, a neck packing part, a nose cast, and an exhalation port. Accordingly, the helmet, including the adsorption filter structure, is designed to be easily detached without protrusion so that a wearer's field of vision is secured, wherein the adsorption filter structure that is not restricted in actions during work is applied. The adsorption layer, the filtration layer, and the shielding layer are stacked therein so as to exhibit optimal efficiency, and thus the filtration efficiency is increased.

An air cleaner assembly includes a precleaner assembly. In one aspect, the precleaner assembly incudes a bypass arrangement that is operated to bypass a portion of air around the precleaner assembly. The bypass arrangement can be operated by a controller based on at least one input signal corresponding to one or more of a vehicle speed, a vehicle engine speed, a vehicle engine load, an operator input, a vehicle location, an air pressure drop across a filter element, an air pressure drop across the precleaner assembly, an acoustic level, a vibration level, a change or cleaning frequency of the filter element, a total number of filter element changes, an identity of the filter element, an identity of the engine, an identity of the vehicle, an air flow rate through the precleaner assembly or through the filter element, and a weather condition parameter identified through data received locally or from a weather service.

A filter assembly 7 for separating contaminants from a fluid stream is described. The filter assembly 7 comprises a filter element 58 which is locatable within chamber 19 in a flow path extending between inlet 54 and outlet 56. The filter element 58 comprises a filter media component 60, and the filter element is locatable within the chamber 19 in the flow path so that fluid flowing from the inlet 54 to the outlet 56 is directed through the filter media component. The filter assembly 7 comprises at least one first alignment assembly having a first alignment component 64a provided by the housing portion 21c and disposed within chamber 19, and a second alignment component 66a provided by the filter element 58. The first and second alignment components 64a and 66a cooperate to rotationally orient the filter element 58 within the chamber 19.

Filtration systems having a normal filtration mode and an enhanced filtration mode are described. In some arrangements, the filtration system is an air filtration system having a primary air filter element, a pre-cleaner, and a pre-cleaner bypass valve. Based on feedback from an intake air quality sensor the bypass valve is either opened or closed to selectively route intake air through the pre-cleaner during sensed dirty air operating conditions (e.g., heavy dust or moisture concentrations). In other arrangements, the filtration system is a liquid filtration system (e.g., a fuel or oil filtration system) that has a main filter and a secondary filter. The filtration system selectively routes the liquid being filtered through the main filter, the secondary filter, or a combination thereof depending on a detected event or sensed characteristic of the liquid.

A filtration system comprises a housing and a shell housing removably coupled to the housing. A valve comprise a valve housing and a plunger. The plunger comprises a seal member structured to seal an opening in the valve housing. The plunger is axially movable between a closed position, in which the seal member seals the opening, and an open position, in which the seal member does not seal the opening, thereby permitting fluid to flow through the valve housing. A filter element comprises filter media and an endcap. The endcap comprises an alignment tab configured to rotationally secure the filter element with respect to the shell housing when the shell housing is received in the housing. The endcap comprise a valve interaction projection structured to transfer rotation of the filter element and the shell housing to the plunger during installation of the filter element.

A filter assembly 7 for separating contaminants from a fluid stream is described. The filter assembly 7 comprises a filter element 58 which is locatable within chamber 19 in a flow path extending between inlet 54 and outlet 56. The filter element 58 comprises a filter media component 60, and the filter element is locatable within the chamber 19 in the flow path so that fluid flowing from the inlet 54 to the outlet 56 is directed through the filter media component. The filter assembly 7 comprises at least one first alignment assembly having a first alignment component 64a provided by the housing portion 21c and disposed within chamber 19, and a second alignment component 66a provided by the filter element 58. The first and second alignment components 64a and 66a cooperate to rotationally orient the filter element 58 within the chamber 19.

An indirect evaporative cooling apparatus includes a housing, a heat exchanger core, a bypass valve, a filter, an indoor fan, and an outdoor fan. The heat exchanger core is in the housing. A first space, a second space, a third space, and a fourth space are formed by the heat exchanger core and the housing, and a first air vent, a second air vent, a third air vent, and a fourth air vent are disposed in the housing. The first space and the second space are connected by using the heat exchanger core to constitute an indoor circulation air duct, the third space and the fourth space are connected by using the heat exchanger core to constitute an outdoor circulation air duct.

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.

A filtration system comprises a housing and a shell housing removably coupled to the housing. A valve comprise a valve housing and a plunger. The plunger comprises a seal member structured to seal an opening in the valve housing. The plunger is axially movable between a closed position, in which the seal member seals the opening, and an open position, in which the seal member does not seal the opening, thereby permitting fluid to flow through the valve housing. A filter element comprises filter media and an endcap. The endcap comprises an alignment tab configured to rotationally secure the filter element with respect to the shell housing when the shell housing is received in the housing. The endcap comprise a valve interaction projection structured to transfer rotation of the filter element and the shell housing to the plunger during installation of the filter element.

A gas valve (11) for ventilation which comprises a main body (12) having a first gas chamber (13), a second gas chamber (15) and at least an inlet duct (14) for supplying a gas to the first gas chamber (13). The gas valve (11) further comprises a proportional valve (24) for temporally sealing the first gas chamber (13) from the second gas chamber (15). The second gas chamber (15) comprises at least a second passage opening (22) for releasing the gas from the second gas chamber (15) and the second gas chamber (15) comprises a port (30) for connecting a pressure measurement apparatus for measuring the gas pressure in the second gas chamber (15). A circuit with a ventilation limb which comprises a gas valve (11) and a method for determining a releasing gas flow of a gas valve are also disclosed.