Disclosed is a method for the removal of soluble particulate matter from a gas stream, such as urea dust from the off-gas of a finishing section of a urea production plant. The method comprises subjecting the off-gas to at least two quenching stages an aqueous quenching liquid. The quenching liquid used in a first, upstream quench stage, is allowed to have a higher concentration of dissolved particulate matter than the quenching liquid in the second, downstream quench stage. The quenched gas is led through a particle capture zone, typically comprising one or more of a wet scrubber, a Venturi scrubber, and a wet electrostatic precipitator.

The disclosed technology regards a wet dust extractor system with a water/solids separator for filtering slurry from the extractor into residue cakes and filtrate water, and related methods of removing dust from an industrial environment and dewatering resulting sludge. The wet dust extractor system has an air inlet, an impeller fan, and an extraction panel. Water is injected at the inlet of the fan impeller, where it is spun with the incoming dust laden air; the resulting slurry then passes to the extraction panel, which removes the slurry from the system by means of a discharge sump. The slurry then is pumped or otherwise delivered to the separator for filtering slurry into residue cakes and filtrate water. The separator includes a frame supporting a plurality of rollers supporting a filter media belt, a plurality of blades and wipers for cleaning the rollers and removing excess filtrate water and cake material, and an inlet water manifold to distribute slurry water uniformly on the filter media belt. The frame supports a filter bed, with a slurry receiving area having a perforated panel at its base, for receiving, pre-filtering and moving the slurry through the separator, and a filter bed collection tub with an exit aperture for collecting and delivering filtrate to a water holding tank. The filter media belt traverses the plurality of rollers, through and about the filter bed, supported along a portion of its path by the perforated panel. Both a residue cake bin and a clean water holding tank may be provided with the system to collect residue and filtrate water, respectively, for re-use or disposal.

The present invention provides an air purifying apparatus that can continuously discharge sludge separated from suctioned contaminated air from a dust collecting apparatus to the outside, thereby improving convenience of use and air purifying performance, and can mix contaminated air with water, eliminate the sludge and contaminants in the air, and allow the eliminated sludge and contaminants to pass through a photocatalytic purifying unit and purify air using a photocatalytic reaction, thereby improving air purifying performance.

Indoor air is purified using a purifying solution in an arrangement capable of removing formaldehyde and other pollutants, such as, for example, particulates. The arrangement can prevent re-vaporization of volatile compounds and can generate air that has been humidified or dehumidified. In one approach, incoming air is contacted with the purifying solution in a packed bed.

A marine exhaust gas scrubbing device including an enclosure having a first end and a second end, an exhaust gas inlet, at least one quencher, at least one pre-treater, at least one venturi component including a venturi inlet and a venturi outlet, an impingement basket, at least one demister, an exhaust gas outlet, and a receiver, and a process for scrubbing a marine exhaust gas including cooling the exhaust gas, pre-treating the exhaust gas, washing the exhaust gas, mixing the exhaust gas and exhausting the scrubbed exhaust gas.

The invention relates to a demister (1) configured for installation to a wet-type gas scrubber (2). The wet-type gas scrubber (2) comprises a wet-scrubbing phase (3) and a liquid separation phase (4). The liquid separation phase (4) includes a liquid collecting tank (5) and a cyclonic droplet separation tower (6) attached on the liquid collecting tank for receiving a gas stream therefrom. The demister (1) comprises a mist eliminator unit (A) for removal of liquid droplets in a gas stream. The invention also relates to a method of modifying an existing wet-type gas scrubber (2) by including the demister (1). The invention further relates to a wet-type gas scrubber (2) comprising the demister (1). The demister (1) is a separate integral unit adapted to be removably attachable between the liquid collecting tank (5) and the cyclonic droplet separation tower (6).