An impact test apparatus can be used to determine particle interfacial energies with varying relative air humidity. It was observed that capillary condensation increased the adhesive forces of hydrophilic materials. A systems humidity separation window was identified and the differences in interfacial energy for a hydrophilic surface and for a hydrophobic surface can be exploited in order to achieve the separation of particles. Separation and concentration of particles, particularly particles within a mineral ore body, can be obtained.

Disclosed is a urea finishing method including an off-gas treatment, the method comprising urea finishing and supplying the off-gas to a quenching zone and to a scrub column comprising a sump and a venturi stage, wherein the sump has a split sump configuration with two compartments.

Disclosed is a urea finishing method including an off-gas treatment, the method comprising urea finishing and supplying the off-gas to a quenching zone and to a scrub column comprising a sump and a venturi stage, wherein the sump has a split sump configuration with two compartments.

A self-cleaning particulate separator unit (10) for use in a ventilation system is provided. The unit is configured to receive a flow of exhaust air containing pollutants, and the particulate separator unit (10) comprises at least one conduit (11) with an outer surface. The conduit (11) is configured to receive a refrigerant. The conduit is configured to have a first temperature and a second temperature. When the conduit has the first temperature condensation and a particle layer of pollutants is formed on the outer surface of the conduit (11), and when the conduit has the second temperature the condensation and the particle layer freezes and subsequently cracks such that the particle layer is detached from the conduit (11). Thus, self-cleaning is obtained.

A droplet generator includes a chamber including an enclosed space filled with gas having vapor, a tube extending through the chamber, a gas flow channel inside the tube, and a heater in the chamber. The tube includes a sidewall having an outer surface exposed to the enclosed space of the chamber, and an inner surface. The tube contains liquid. The heater is operable to change a phase of the liquid contained in the tube to vapor such that the vapor is provided into the enclosed space. A pressure in the enclosed space is higher than a pressure in the gas flow channel such that the vapor in the enclosed space flows to the gas flow channel by passing through the tube.

A method of capturing soot includes the steps: combusting a first precursor in a burner to produce a soot stream, the soot stream comprising soot and exiting the burner at an outlet; and directing a capture medium to the soot stream, the capture medium contacting the soot in an impact region, the soot having a temperature greater than 50° C. in the impact region.

A method of capturing soot includes the steps: combusting a first precursor in a burner to produce a soot stream, the soot stream comprising soot and exiting the burner at an outlet; and directing a capture medium to the soot stream, the capture medium contacting the soot in an impact region, the soot having a temperature greater than 50° C. in the impact region.

Disclosed is a method for the removal of urea dust from the off-gas of a finishing section of a urea production plant. the method comprises subjecting the off-gas to quenching with water so as to produce quenched off-gas. The quenched off-gas is subjected to humidification by mixing said quenched gas stream with a humidification fluid selected from (a) saturated steam and (b) superheated steam mixed with a second aqueous stream, so as to produce a humidified gas stream, subjecting said humidified gas stream to particle separation (i.e., dust removal) by means of a scrubbing liquid in which at least part of the particles in the gas stream are soluble.

Disclosed is a method for the removal of urea dust from the off-gas of a finishing section of a urea production plant. the method comprises subjecting the off-gas to quenching with water so as to produce quenched off-gas. The quenched off-gas is subjected to humidification by mixing said quenched gas stream with a humidification fluid selected from (a) saturated steam and (b) superheated steam mixed with a second aqueous stream, so as to produce a humidified gas stream, subjecting said humidified gas stream to particle separation (i.e., dust removal) by means of a scrubbing liquid in which at least part of the particles in the gas stream are soluble.

The present invention relates to a method and to an apparatus for separating an exhaust gas, in particular an exhaust gas of a boiler, comprising introducing a gas stream of exhaust gas inside a washing chamber, dispensing a pressurized liquid shaped as drops inside the washing chamber, wherein the delivery pressure is adjusted according to the specific particulate to be separated so as to provide, during the separating step, a physical interaction between the delivered liquid drops and the particulate particles.