System and methods for solder flux removal from a gas stream is disclosed. In one aspect, the system includes: a scrubber chamber having a gas inlet and a gas outlet through which the gas stream is introduced into and withdrawn from the scrubber chamber; at least one rinse agent delivery mechanism for introducing a rinse agent into the scrubber chamber for contact with the gas stream, the rinse agent being at a temperature for condensing a first portion of the flux from the gas stream; a condenser portion of the scrubber chamber containing the rinse agent for receiving the gas stream, the rinse agent being at a temperature for condensing a second portion of the flux in the gas stream; and a condensed flux removal apparatus adapted for removal from the scrubber chamber of at least a portion of the rinse agent and the flux which has condensed.

Methods, apparatus, and compositions for cleaning gas. The use of segmented multistage ammonia-based liquid spray with different oxidation potentials to remove sulfur compounds from gas. The use of different oxidation potentials may reduce unwanted ammonia slip.

According to one embodiment, a dust collection apparatus includes a liquid supplier, a first member, and a liquid recoverer. One end of the first member is connected to the liquid supplier, one other end of the first member is connected to the liquid recoverer. The first member is conductive. The first member has a first surface including a plurality of trenches.

A multi-mechanism wet dust removal apparatus achieving water circulation use and a dust removal method. The multi-mechanism wet dust removal apparatus includes a dust collecting device, a dust settling and air-water separation device, a water circulating device and a dust discharging device, and dust removal is achieved by dust collecting, dust settling, air-water separation and dust discharging. The multi-mechanism wet dust removal apparatus achieving water circulation use and the dust removal method integrate multiple dust removal mechanisms, and the dust removal efficiency and effect are obvious.

Methods, apparatus, and compositions for cleaning gas. The use of segmented multistage ammonia-based liquid spray with different oxidation potentials to remove sulfur compounds from gas. The use of different oxidation potentials may reduce unwanted ammonia slip.

An integrated process for production of urea and urea-ammonium sulphate (UAS) comprises: a urea synthesis step carried out in a urea synthesis reactor; a recovery and concentration step, wherein a urea solution produced in the urea synthesis step is progressively concentrated in at least one recovery section and in a concentration section, recovering unreacted ammonia and carbon dioxide and water from said urea solution; a step of producing ammonium sulphate by reaction of sulphuric acid and ammonia in an ammonium sulphate production apparatus; a step of mixing said ammonium sulphate with concentrated urea coming from the concentration section to produce a UAS mixture; in the ammonium sulphate production step, at least a part of the ammonia is provided by at least one off-gas containing ammonia and recovered from the recovery and concentration step.

Methods, apparatus, and compositions for cleaning gas. The use of segmented multistage ammonia-based liquid spray with different oxidation potentials to remove sulfur compounds from gas. The use of different oxidation potentials may reduce unwanted ammonia slip.

A gas inlet system for a wet gas scrubber includes a weir configured to deliver liquid to a scrubbing passage to wet the interior surface of the scrubbing vessel during operation of the gas inlet system. The weir include a weir duct and a weir trough extending at least partially around the weir duct to receive and at least partially fill with liquid during operation of the gas inlet system. The weir trough has an upper trough outlet in liquid communication with the upper weir duct inlet to deliver liquid from the weir trough into the upper weir duct inlet during operation of the gas inlet system. The weir trough also has a lower trough outlet below the upper trough outlet. The lower trough outlet is in liquid communication with the scrubbing passage to deliver liquid from the weir trough toward the scrubbing passage during operation of the gas inlet system.

A gas inlet system for a wet gas scrubber includes a weir configured to deliver liquid to a scrubbing passage to wet the interior surface of the scrubbing vessel during operation of the gas inlet system. The weir include a weir duct and a weir trough extending at least partially around the weir duct to receive and at least partially fill with liquid during operation of the gas inlet system. The weir trough has an upper trough outlet in liquid communication with the upper weir duct inlet to deliver liquid from the weir trough into the upper weir duct inlet during operation of the gas inlet system. The weir trough also has a lower trough outlet below the upper trough outlet. The lower trough outlet is in liquid communication with the scrubbing passage to deliver liquid from the weir trough toward the scrubbing passage during operation of the gas inlet system.

A flue gas cleaning solution purification system includes: a scrubber for removing contaminants from flue gas by using a cleaning solution; a cleaning solution purification unit for purifying the contaminated cleaning solution discharged from the scrubber; a cleaning solution resupply unit for resupplying the cleaning solution having been purified by the cleaning solution purification unit to the scrubber; and a sludge treatment unit for treating and storing sludge discharged from the cleaning solution purification unit, wherein the cleaning solution purification unit includes: a circulation buffer tank for temporarily storing the discharged contaminated cleaning solution; a coagulant supply apparatus for supplying a coagulant which coagulates contaminants of the contaminated cleaning solution discharged from the scrubber; a settling apparatus for primarily purifying the contaminated cleaning solution discharged from the scrubber by enabling settling of the contaminants; and a filtering apparatus for secondarily purifying the cleaning solution by filtering the contaminated cleaning solution to remove the contaminants.