Ionization systems and methods include moving air into contact with one or more ion generators and then past an ozone removal assembly to remove at least some ozone from the air. The air may be moved by a fan and may be filtered before contacting the one or more ion generators. The amount of one or more of the following of the air may be measured: the amount of ions, particulates, temperature, humidity, and other relevant factors. The ionization amount may be adjusted based on one or more of the measured amounts. The one or more ion generators and ozone removal assembly may be constructed as part of a single unit so they can be removed and replaced easily.

The present invention relates to a method for adaption of an exhaust treatment system arranged for treating an exhaust stream produced by an engine, where the exhaust treatment system includes at least a first additive dosage device, a first selective catalytic reduction catalyst arranged downstream of the first additive dosage device, a second additive dosage device arranged downstream of the first selective catalytic reduction catalyst, and a second selective catalytic reduction catalyst arranged downstream of the second additive dosage device. The method includes initiating an adaption of the second selective catalytic reduction catalyst, and controlling, during the adaption of the second selective catalytic reduction catalyst, the first additive dosage device to inject additive in accordance with at least one injection rule being designed for the adaption.

A powder sieving system that is configured as part of a powder reclamation system is provided. The powder sieving system includes a support structure; and a filter housing movable relative to the support structure, the filter housing defining an inlet and an outlet and comprising a broad frequency filter disposed between the inlet and the outlet, the broad frequency filter including: a first filter fixed relative to the filter housing, the first filter being substantially rigid; and a second filter coupled within the filter housing adjacent to the first filter, the second filter being substantially flexible such that the second filter is movable relative to the first filter within the filter housing when the filter housing moves relative to the support structure, the first filter and the second filter configured to restrict a first portion of a powder larger than a predetermined threshold from reaching the outlet.

The devices, systems and techniques disclosed in this patent document include photocatalytic filter devices and can be used to provide a method for manufacturing a photocatalytic filter with improved adhesion. In addition, the present disclosure of this patent document includes technology to provide a method for reactivating a photocatalytic filter. Using the disclosed techniques, even if a photocatalytic filter is contaminated, the contaminated photocatalytic filter is easily reactivated while maintaining improved adhesion.

Disclosed herein are systems and methods for treating air.

An exhaust aftertreatment system for an internal combustion engine includes an outer casing having an exhaust gas inlet and an exhaust gas outlet between which a fluid flow path for exhaust gases is provided, a selective catalytic reduction unit provided in the fluid flow path for reducing nitrogen oxides, a reductant dosing device for adding reductant to the exhaust flow upstream of the selective catalytic reduction unit, and a rotatable mixer device for mixing the reductant with exhaust gases upstream of the selective catalytic reduction unit, an air inlet valve provided upstream of the mixer device for introducing air into the fluid flow path, and an electric motor arranged for rotating the mixer device to create a suction of air into the fluid flow path via the air inlet valve.

A method of converting a liquid hydrocarbon stream to lower boiling point hydrocarbons may include converting the liquid hydrocarbon stream to an aerosolized hydrocarbon particle stream, and subjecting the aerosolized hydrocarbon particle stream to reaction conditions. Reaction conditions may include a temperature from 25° C. to 1,000° C. and a pressure from 1 bar to 15 bar. The method may further include forming the lower boiling point hydrocarbons in the aerosolized hydrocarbon particle stream and separating the lower boiling point hydrocarbons from the aerosolized hydrocarbon particle stream. The lower boiling point hydrocarbons may comprise at least C.sub.2-C.sub.4 olefins.

An air purification system includes a conduit extending between an inlet and an outlet, each in fluid communication with an enclosed environment. Ambient air from the enclosed environment enters the conduit via the inlet and treated air exits the conduit and enters the enclosed environment via the outlet. The system further includes a fibrous filter disposed within the conduit and configured to treat the ambient air thereby generating the treated air, and a renewal unit disposed within the conduit and configured to renew the fibrous filter.

A vertical humidifier with a stepped evaporator includes a housing. An evaporative water trough is provided inside the housing, and the stepped evaporator is provided in the evaporative water trough. A fan is mounted under the stepped evaporator, and an air inlet end of the fan is communicated with an air inlet of the housing. A water tank is further mounted at the upper portion of the evaporative water trough, the stepped evaporator is mounted around the lower portion of the water tank, and the water tank is further communicated with the evaporative water trough through a water inlet. An air outlet is provided at the upper portion of the housing, and the air outlet is communicated with an air outlet end of the fan. The stepped evaporator is arranged in an airflow channel between the air outlet and the air outlet end of the fan.

A filtering system includes a catalyst filter including a plurality of channels through which air is introduced, and a light-emitting device arranged to irradiate light to the catalyst filter for catalyst activation, where the light-emitting device includes a light source array including a plurality of first light sources corresponding one-to-one with the plurality of channels. Each of the plurality of first light sources may include a substrate, a first light-emitting device on the substrate, and a capsule which seals the first light-emitting device on the substrate. Only one first light-emitting device is provided in the capsule, or a second light-emitting device is further provided together with the first light-emitting device in the capsule.