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.

A high-efficiency gradient hierarchy complex desulfurizing tower includes a tower body. The tower body tower includes an oxidization and crystallization stage, a coarse desulfurization and dedusting stage, a fine desulfurization and dedusting stage, and a horizontal demisting stage from the bottom up. The oxidization and crystallization stage tower includes a pond and a separation mechanism provided in the pond and separating the pond into an upper area and a lower area. The coarse desulfurization and dedusting stage tower includes a gas distributing board and a multi-layer spray layer that are placed above a gas import, the spray layer being in connection with the pond. The fine desulfurization and dedusting stage tower includes a tube demister, a flushing layer, a film liquid holdup layer, a liquid holdup layer recycling can, the pH of slurry in the liquid holdup layer recycling can being higher than the pH of slurry in the pond.

A high-efficiency gradient hierarchy complex desulfurizing tower includes a tower body. The tower body tower includes an oxidization and crystallization stage, a coarse desulfurization and dedusting stage, a fine desulfurization and dedusting stage, and a horizontal demisting stage from the bottom up. The oxidization and crystallization stage tower includes a pond and a separation mechanism provided in the pond and separating the pond into an upper area and a lower area. The coarse desulfurization and dedusting stage tower includes a gas distributing board and a multi-layer spray layer that are placed above a gas import, the spray layer being in connection with the pond. The fine desulfurization and dedusting stage tower includes a tube demister, a flushing layer, a film liquid holdup layer, a liquid holdup layer recycling can, the pH of slurry in the liquid holdup layer recycling can being higher than the pH of slurry in the pond.

A wet scrubber apparatus has a housing with access doors and guides that allow for the installation of self-contained baffle modules. Selected baffle modules can to be inserted, exchanged, removed or left blank (no baffles) within the wet scrubber housing, depending on the desired process. The wet scrubber allows for variable performance and feature-enhancing for a target efficiency and effectiveness. The wet scrubber can incorporate a pump and pipe manifold fluidizer design that can spray water or fluid up onto the modules during operation of the wet scrubber to keep collected material off the baffles. Water can be sprayed throughout the modules onto the baffles during operation, or when the scrubber is offline, isolated from the gas to be scrubbed, during a cleaning operation. This water or fluid can come from an outside source or can be piped and valved to recirculate existing scrub water or fluid.

A foreign substance collecting apparatus according to one embodiment of the present disclosure may comprise: a collection body unit formed with a suction port through which air including foreign substances flows in and a discharge port through which air removed of the foreign substances is discharged; and a mixing unit provided inside the collection body unit and disposed on a flow passage of the air, and forming a vortex in washing water contained therein by inducing a rotary flow of the air.

In a method of treating a gas stream (32) containing combustible and/or reactive particles (34) at least a part of the particles (34) contained in the gas stream (32) is separated from the gas stream (32) by means of a separation device (36). The particles (34) separated from the gas stream (32) by means of the separation device (36) are supplied to a collecting vessel (40). The supply of particles (34) to the collecting vessel (40) is interrupted. A flame retardant material (57) is supplied to the collecting vessel (40) so as to form a cover layer of flame retardant material (57) on the particles (34) contained in the collecting vessel (40).

In a method of treating a gas stream (32) containing combustible and/or reactive particles (34) at least a part of the particles (34) contained in the gas stream (32) is separated from the gas stream (32) by means of a separation device (36). The particles (34) separated from the gas stream (32) by means of the separation device (36) are supplied to a collecting vessel (40). The supply of particles (34) to the collecting vessel (40) is interrupted. A flame retardant material (57) is supplied to the collecting vessel (40) so as to form a cover layer of flame retardant material (57) on the particles (34) contained in the collecting vessel (40).

A system for scrubbing chemicals and particulate matter from exhaust emissions using steam and water is provided. The system includes an exhaust pipe having an inlet and an outlet. The exhaust pipe is inclined by at least 2 degrees with respect to horizontal. Water and steam supply lines run parallel to the exhaust pipe and connect to a plurality of water and steam nozzles to inject water/steam into the exhaust pipe cocurrent to the direction of emissions flow. The nozzles are positioned along the length, and around the circumference, of the exhaust pipe to inject water/steam into the exhaust pipe from multiple directions to saturate at least a cross sectional area of the interior volume of the exhaust pipe with water/steam. Absorbed chemicals and particulate matter collect as wastewater at bottom of the exhaust pipe and drain by gravity into a reservoir positioned below the outlet.

A system for scrubbing chemicals and particulate matter from exhaust emissions using steam and water is provided. The system includes an exhaust pipe having an inlet and an outlet. The exhaust pipe is inclined by at least 2 degrees with respect to horizontal. Water and steam supply lines run parallel to the exhaust pipe and connect to a plurality of water and steam nozzles to inject water/steam into the exhaust pipe cocurrent to the direction of emissions flow. The nozzles are positioned along the length, and around the circumference, of the exhaust pipe to inject water/steam into the exhaust pipe from multiple directions to saturate at least a cross sectional area of the interior volume of the exhaust pipe with water/steam. Absorbed chemicals and particulate matter collect as wastewater at bottom of the exhaust pipe and drain by gravity into a reservoir positioned below the outlet.

In a method of treating a gas stream (32) containing combustible and/or reactive particles (34) at least a part of the particles (34) contained in the gas stream (32) is separated from the gas stream (32) by means of a separation device (36). The particles (34) separated from the gas stream (32) by means of the separation device (36) are supplied to a collecting vessel (40). The supply of particles (34) to the collecting vessel (40) is interrupted. A flame retardant material (57) is supplied to the collecting vessel (40) so as to form a cover layer of flame retardant material (57) on the particles (34) contained in the collecting vessel (40).