Abstract: The life of a sacrificial anode for use in a pump device, such as a seawater pump, is extended, thus extending the life of a corrosion protection system of the seawater pump device. A pump device includes corrosion system including: a measurement unit located at a portion of a column pipe to be immersed into seawater; and a temperature control device located at an installation site of the pump device. In this corrosion protection system, a sacrificial anode electrically conductive with the column pipe and capable of being controlled in temperature is attached through a heating/cooling unit and a thermal conduction sheet to the column pipe. The temperature control device is configured to control, based on the temperature of the sacrificial anode measured by the measurement unit, the temperature of the sacrificial anode using the heating/cooling unit attached through the thermal conduction sheet to the sacrificial anode.

Abstract: To provide a can manufacturing pump impeller in which a stress of a base portion of a blade is prevented from increasing while improving the strength of a joint portion of a hub and a boss. In order to reinforce a joint portion of a hub and a boss, a plate is jointed to the inside of an impeller. In order not to overlap a base portion of a blade and the plate with each other on the hub, an opening portion is provided in the plate around the base portion of the blade on the hub. As a shape of the opening portion, a semicircular shape, a semielliptical shape, a rectangular shape, or a trapezoidal shape can be selected. Further, as a plate shape, a flat plate structure, a shell structure, or a curved structure can be selected.

Abstract: In an industrial pump, a bearing provided in a pump main body rotatably supports both end sides of a rotating shaft to which an impeller is attached. A shaft seal apparatus is arranged in adjacent to the bearing. The shaft seal apparatus is cooled by a cooling water introduced from an external portion. A shaft seal case is fitted to an inner peripheral surface of a bracket accommodating the shaft seal apparatus in accordance with a shrink fitting. A cooling water is circulated in a boundary portion between the bracket and the shaft seal case. It is omitted a work for closing an opening portion of a cooling means for circulating the cooling water by welding.

Abstract: To provide a can manufacturing pump impeller in which a stress of a base portion of a blade is prevented from increasing while improving the strength of a joint portion of a hub and a boss. In order to reinforce a joint portion of a hub and a boss, a plate is jointed to the inside of an impeller. In order not to overlap a base portion of a blade and the plate with each other on the hub, an opening portion is provided in the plate around the base portion of the blade on the hub. As a shape of the opening portion, a semicircular shape, a semielliptical shape, a rectangular shape, or a trapezoidal shape can be selected. Further, as a plate shape, a flat plate structure, a shell structure, or a curved structure can be selected.

Abstract: The object of the present invention is to provide a pump structure that can reduce a hydraulic force applied to a casing of a multi stage diffuser pump, which includes multiple stages of impellers fixed to a rotary shaft rotatably supported in the casing and multiple stages of guide vane diffusers and return blade passages fixed on the casing in correspondence with the multiple stages of impellers, thereby reducing the vibrations and noises of the pump. In a multi stage diffuser pump of the type which includes multiple stages of impellers fixed to the rotary shaft and multiple stages of guide vane diffusers and return blade passages fixed on circular disks in the casing in correspondence with the multiple stages of impellers, in the impellers of the two stages of front and rear stages, which are equivalent in the form and number of blades, the phases of positions in the peripheral direction of the blades of the impellers of at least one pair of front and rear stages are deviated from each other by 0.

Abstract: A single-shaft multistage pump is provided to make small-sized and space-saved possible. The single-shaft multistage pump includes a rotary shaft on which impellers are disposed at multiple stages, bearings and for supporting the rotary shaft, and a balance device adapted to apply, to the rotary shaft, a balance thrust force opposing an impeller thrust force. A water-lubricated bearing is used as each of the radial bearings, and the rotary shaft is supported by the water-lubricated bearings with a balance member of the balance device interposed therebetween.

Abstract: In an industrial pump, a bearing provided in a pump main body rotatably supports both end sides of a rotating shaft to which an impeller is attached. A shaft seal apparatus is arranged in adjacent to the bearing. The shaft seal apparatus is cooled by a cooling water introduced from an external portion. A shaft seal case is fitted to an inner peripheral surface of a bracket accommodating the shaft seal apparatus in accordance with a shrink fitting. A cooling water is circulated in a boundary portion between the bracket and the shaft seal case. It is omitted a work for closing an opening portion of a cooling means for circulating the cooling water by welding.

Abstract: A single-shaft multistage pump is provided to make small-sized and space-saved possible. The single-shaft multistage pump includes a rotary shaft on which impellers are disposed at multiple stages, bearings and for supporting the rotary shaft, and a balance device adapted to apply, to the rotary shaft, a balance thrust force opposing an impeller thrust force. A water-lubricated bearing is used as each of the radial bearings, and the rotary shaft is supported by the water-lubricated bearings with a balance member of the balance device interposed therebetween.

Abstract: A primer comprises a liquid epoxy resin, a hydrophobic polyamine compound, a thixotropic agent and a silane coupling agent. After coating the primer on a wet concrete surface of a structure, a reinforced fiber sheet or similar material could be attached to the surface with a high level of adhesive strength without being influenced by the water. The reinforced fiber sheet is impregnated with a matrix resin and cured to achieve a satisfactory reinforcement of the concrete structure.