Abstract: An axial impeller has blades formed from sheet metal blanks that are configured from taking a desired impeller blade and mathematically “unwinding” the blade to its flat counterpart. Preferably, the impeller blade is formed from a single rolling operation. The result of a thin, elongate blade, preferably having a trailing edge that defines a helix with rearwardly skewed, forwardly raked blades, provides an efficient impeller having good anti-ragging properties.

Abstract: An axial impeller has blades formed from sheet metal blanks that are configured from taking a desired impeller blade and mathematically “unwinding” the blade to its flat counterpart. Preferably, the impeller blade is formed from a single rolling operation. The result of a thin, elongate blade, preferably having a trailing edge that defines a helix with rearwardly skewed, forwardly raked blades, provides an efficient impeller having good anti-ragging properties.

Abstract: An apparatus and method for mixing a liquid having particulate includes a vessel for containing me liquid an axial impeller rotating about a substantially vertical axis. The impeller is adapted for submerging below the liquid surface by a distance approximately one-quarter to one-half of the height of the liquid. The impeller is oriented upwardly to produce (a) an inner, upward flow region located along the vertical axis of the vessel, (b) a transition flow region above the impeller in which liquid moves radially outwardly toward the vessel sidewall, and (c) an outer, downward flow region located along the sidewall. The impeller spins at a variable speed, such that the flow is capable of entraining solid particles having a settling velocity of up to approximately 1 foot per minute in the liquid, and the speed of the impeller is chosen to enable particles having a desired settling velocity to settle to the vessel bottom.

Abstract: An apparatus and method for mixing a liquid having particulate includes a vessel for containing the liquid and an axial impeller rotating about a substantially vertical axis. The impeller is adapted for submerging below the liquid surface by a distance approximately one-quarter to one-half of the height of the liquid. The impeller is oriented upwardly to produce (a) an inner, upward flow region located along the vertical axis of the vessel, (b) a transition flow region above the impeller in which liquid moves radially outwardly toward the vessel sidewall, and (c) an outer, downward flow region located along the sidewall. The impeller spins at a variable speed, such that the flow is capable of entraining solid particles having a settling velocity of up to approximately 1 foot per minute in the liquid, and the speed of the impeller is chosen to enable particles having a desired settling velocity to settle to the vessel bottom.

Abstract: A method of mixing paper stock, having improved outlet consistency, includes: (a) feeding liquid and feeding paper pulp into a vessel to form a mixture; (b) providing at least one counterflow impeller that is submerged in the mixture, the counterflow impeller being capable of simultaneously inducing both upward flow and downward flow; (c) rotating the counterflow impeller such that downward flow from the impeller is partially recirculated by upward flow from the impeller to form a mixing zone; (d) sensing a parameter of the mixture discharged from the vessel; and (e) controlling the feed rate of the liquid and the feed rate of the paper pulp in the feeding step (a) based on the sensing step (d). An apparatus for mixing of paper stock, having improved outlet consistency, includes a vessel for containing liquid and paper pulp, at least one counterflow impeller, and a feedback system for controlling outlet consistency.

Abstract: An impeller, a system for mixing a fluid, and a method of mixing a fluid in a tank are disclosed. For a sufficiently small impeller diameter and maximum blade tip velocity, the disclosed impeller, system, and method are capable of accelerating a near-zero intake velocity fluid, to generate a mixing zone that is collimated enough to have sufficient velocity vectors to suspend particles at a large distance away from the impeller, while minimizing the required power draw. An impeller may include a hub defining a longitudinal axis and plural blades spaced circumferentially about the hub. Each blade may include a root portion and a tip portion. Each blade may define a leading edge having an approximately circular raked helical geometry. A system for mixing a fluid may include a tank for containing the fluid, a drive shaft for extending into the tank, and the impeller.

Abstract: A crystallizer system for forming solid crystals includes a vessel defining a cylindrical sidewall, a sparge device located at a bottom of the vessel, a plurality of impellers attached to a shaft, and a plurality of redistribution funnel assemblies vertically spaced apart. Each funnel assembly may be positioned underneath a respective impeller of the plurality of impellers. Each funnel assembly may include a funnel, a disc attached to the shaft such that the disc rotates with the impellers, and a channel extending radially inward from a location near the sidewall. The channel may be adapted to direct gas bubbles from the sidewall to a location near blade outer edges of the respective impeller A lower edge of the funnel and the disc may define a lower gap therebetween, such that solid particles falling from within the funnel are directed out of the lower gap when the disc is rotated.

Abstract: An impeller assembly includes a shaft, multiple scoops spaced circumferentially about the shaft, each scoop including an upper blade portion and a lower blade portion, spaced apart at the leading edges and joined at the inner edges, and a rib extending rearward from the inner edges, each scoop being coupled to the shaft by attachment at the rib. A system and method for mixing gas or liquid into liquid include a vessel for containing liquid, a drive shaft for extending into the vessel, and an impeller assembly adapted for rotating about the drive shaft, adapted for submerging below the liquid surface, and having multiple scoops, each scoop including an upper blade portion and a lower blade portion, spaced apart at the leading edges and joined at the inner edges, and a rib extending rearward from the inner edges, each scoop being coupled to the shaft by attachment at the rib.

Abstract: A diffuser which includes a cylinder open at one end and closed at the opposite end, the open end of the cylinder being securable to air supply; the wall of the diffuser being formed with a plurality of holes therethrough, each hole having a larger diameter on the exterior of the wall of the diffuser than on the interior of the wall of the diffuser, the longitudinal axis of each hole being inclined at an acute angle to both the radius and the longitudinal axis of the diffuser, and the orientation of each hole with respect to the longitudinal axis of the diffuser being such that when the diffuser is rotated about it longitudinal axis in use, the leading edge of each hole is at a higher elevation than the trailing edge of each hole.