An impeller structure for a centrifugal pump that can feed both fibrous suspensions and water into a headbox of a fibrous web machine. The centrifugal pump utilizing the impeller structure pumps stock for both liquid-laid and foam-laid paper, tissue or board making applications and pumps water or other dilution fluid into a headbox circulation. In general, the impeller of the present invention is especially suitable for all such pumping tasks in the production of fibrous webs that a pulseless or low-pulse impeller is needed.

An impeller that rotates about a central axis extending vertically includes a base portion and blades. The base portion spreads perpendicularly to the central axis. The blades are on an upper surface of the base portion at intervals in a circumferential direction. The base portion includes an irregular portion that is radially outward and in which irregularities are repeated in the circumferential direction. The irregular portion includes one or more first irregular regions and a second irregular region. The first irregular regions include first recesses with a same shape and first projections with same shape, the first recesses and projections being alternately arranged one by one. The second irregular region is positioned between the first irregular regions and includes at least one among a second recess with a different shape from the first recesses and a second projection with a different shape from the first projections.

A centrifugal blower includes: a centrifugal fan, which includes a shroud ring; and a case. The case includes a cover portion that covers a surface of the shroud ring located on one side in an axial direction. The cover portion includes a recess formed in a cover opposing surface, which is opposed to the shroud ring, and the recess is shaped in a form of a circle. The shroud ring includes at least one projection that is formed in a ring opposing surface, which is opposed to the cover portion. A gap is formed between the cover portion and the shroud ring. A shortest distance between a radially inner end part of the shroud ring and the cover portion is set to be larger than a shortest distance between a surface of the projection and a surface of the recess.

A centrifuge turbo machinery includes an impeller which rotates about an axis to pressure-feed fluid flowing along the axis to an outer side in a radial direction, and a casing which accommodates the impeller and has a facing surface facing the impeller in an axial direction. A convex portion relatively close to the impeller and extending in the radial direction and a concave portion relatively spaced apart from the impeller and extending in the radial direction are alternately and continuously formed on the facing surface in a circumferential direction.

This disclosure includes anti-reverse rotation apparatuses, rotors for use therein, and related methods. Some apparatuses include a stator defining an interior volume and one or more arcuate contact surfaces within the interior volume, and a rotor rotatably coupled to the stator and at least partially disposed within the interior volume, the rotor having a hub, two or more shoes, each pivotally coupled to the hub and extending between a first end and a second end that is farther from the hub than is the first end, wherein each of the shoes is rotatable relative to the hub between: (a) a first position in which the second end of the shoe contacts at least one of the arcuate contact surface(s) of the stator; and (b) a second position in which the second end of the shoe does not contact the arcuate contact surface(s) of the stator.

An electric submersible pump including a housing having a longitudinal axis extending therethrough; and a plurality of stages disposed within the housing each stage having an impeller and a diffuser, the plurality of stages stackable one upon the other along the longitudinal axis of the housing, wherein one or more of the plurality of stages is a standard flow stage, wherein one or more of the plurality of stages is an anti-gas lock flow stage, and wherein the anti-gas lock flow stages are modified relative the standard flow stages to have decreased incidence of trapped gas.

This disclosure includes anti-reverse rotation apparatuses, rotors for use therein, and related methods. Some apparatuses include a stator defining an interior volume and one or more arcuate contact surfaces within the interior volume, and a rotor rotatably coupled to the stator and at least partially disposed within the interior volume, the rotor having a hub, two or more shoes, each pivotally coupled to the hub and extending between a first end and a second end that is farther from the hub than is the first end, wherein each of the shoes is rotatable relative to the hub between: (a) a first position in which the second end of the shoe contacts at least one of the arcuate contact surface(s) of the stator; and (b) a second position in which the second end of the shoe does not contact the arcuate contact surface(s) of the stator.

An impeller spinner for a fuel pump can include a head and a shank. The head can have a base at one end and a tip at an opposite end. The shank can have a body portion nearest the head with a first diameter and a fastener portion adjacent to the body portion at an end opposite the head with a second diameter.

An improved rotary machine of the invention may include a rotor with an impeller mounted thereon. A side cavity may be formed between an impeller and the housing. The rotary machine may be further equipped with an annular subdividing disk for segmenting a fluid flow in the cavity into a first fluid flow between the disc and the impeller, and a second fluid flow on the other side of the disk between the disc and the housing. The rotary machine of the invention also features a peripheral annular space formed in the periphery of the housing in the cavity at a location adjacent to a peripheral region of the annular subdividing disk. Importantly, this peripheral annular space is void of restrictions to circumferential fluid flow therein so as to alter the second fluid flow in the cavity in order to reduce pressure variations and flow disturbances along the circumference of the rotary machine. This in turn improves rotational balance of the rotary machine.

The present invention relates to a centrifugal pump, the impeller of which comprises a shroud (34) with at least one solid and rigid working vane (36), and at least one solid and rigid rear vane (38), the at least one working vane (36) having a leading edge region (46), a trailing edge region (48), a central region (C), a side edge, a pressure face (42) and a suction face (44), the at least one solid and rigid rear vane (38) having a trailing edge region, a side edge, a pressure face and a suction face. The trailing edge region (48) of the at least one working vane (36) is rounded by means of a rounding to have a thickness greater than that in the central region (C).