An air filter with a life timing feature includes a filter body and a mounted detachable filter grille. The filter grille's life timing is monitored by a life timing device, which consists of a limit frame on the filter body, a first induction piece, a second induction piece, and a timer electrically connected to the first induction piece. The first induction piece is connected to the limit frame, while the second induction piece is hinged to the first induction piece. The second induction piece is positioned on the outer side of the limit frame and interacts with a sensing part within the first induction piece. When the detachable filter grille is mounted on the limit frame and engages with the pressure plate of the second induction piece, the second induction piece engages with the sensing part, activating the timer to initiate the life timing of the filter grille.

The present disclosure relates generally to air intake filter assemblies, and more particularly to air intake assemblies for an outdoor portion of a heating, ventilation, and/or air conditioning (HVAC) system. In an embodiment, a filter assembly is configured to filter an airflow entering an air intake of a HVAC unit. The filter assembly includes a first layer of a first coarse mesh, a second layer of a second coarse mesh, and a fine filter disposed between the first layer and the second layer. Additionally, the fine filter includes an upper level and a lower level with respect to the airflow, and wherein the lower level facilitates accumulation of fine debris captured from the airflow entering the air intake of the HVAC unit.

A filter element for a filter assembly includes a filter media, a main seal, and a planar side seal. The main seal is coupled to an outer periphery of the filter media and disposed in a main seal plane perpendicular to a first side wall of the filter element. The planar side seal is coupled to and extends outward from the first side wall, and diverges away from the main seal plane.

Filters for use with protective masks are described, including a container with an interface for removably securing the filter to the exterior of a protective mask, a first mechanical filter screen disposed between an interior of the container and atmosphere, a second mechanical filter screen disposed between an interior of the container and an inner volume of the protective mask, and a filtering medium disposed in the container. The filtering medium includes active particles that are loose, substantially uniform in size, and derived from a polymeric precursor, such as polyvinylidene chloride (PVDC), polyvinylidene fluoride (PVDF), a PVDC copolymer, or a PVDF copolymer. The active particles include metallic additives and organic additives, and a ratio of standard deviation of the active particles' dimensions compared to an average particle dimension may be less than 0.35. Methods of manufacturing such filters, and protective masks including filters with the foregoing features, are also described.

A filter module, including a plurality of filter elements for separating overspray from an air flow, the filter module including a reusable and cleanable frame configured as a support structure for components for collecting overspray, and a plurality of components inserted into the frame for collecting overspray, wherein the components for collecting overspray are at least filter elements and linings in the frame, which are configured as disposable, single-use products the filter elements form at least a first filter stage, and all the surfaces of the frame which are exposed to the air flow upstream of the first filter stage are provided with the linings such that the surfaces of the frame are protected against overspray.

A metal foam-based filtration system and method for removing sub-micron particles and contaminants from a gas or fluid flow with the use of ultralow density metal nanowire meshes that have nanometer to micron scale pores for trapping air/fluid-borne particulates. Filters can use metal foams and coated metal foams alone or in tandem. The size and density of pores in the foam can be adjusted with synthesis conditions. Foams with pore size gradients promote the trapping of different sized particulates at different regions of a foam. Multiple rounds of electrodeposition may be applied to increase the surface area and curvature of a nanowire mesh and strengthen the mesh to make it self-supporting, free-standing and capable of supporting a much heavier mass without collapse. A metal and/or a coated metal foam can act as a catalyst or substrate for absorption or adsorption to capture target particles and/or contaminants.

A filter assembly that includes a filter housing with a housing interlocking feature, a filter cover with a filter cover interlocking feature, and a filter element with a filter element interlocking feature is disclosed. The filter element is positionable within the filter housing, and the filter cover is attachable to a top portion of at least one of the filter element and the filter housing. The housing interlocking feature, the filter cover interlocking feature, and the filter element interlocking feature are interlockable with each other and extend in a nonplanar configuration along at least one side of the filter element when the filter housing, the filter cover, and the filter element are assembled together.

A waste heat recovery and utilization system includes a material waste heat extraction subsystem, a flue gas waste heat recovery subsystem and a control subsystem; the material waste heat extraction subsystem is in communication with the flue gas waste heat recovery subsystem for extracting, by utilizing a flue gas flowing through the material waste heat extraction subsystem, a waste heat from a material with waste heat to be recovered; the flue gas waste heat recovery subsystem is used for recovering a waste heat of flue gas discharged from an aluminum electrolytic cell and a waste heat extracted from the material with waste heat to be recovered; and the control subsystem is used for regulating and controlling operational parameters of the material waste heat extraction subsystem and the flue gas waste heat recovery subsystem during waste heat recovery and utilization.