Vertical axial flow pump characteristics, the basic structure and installation methods

Vertical axial flow pump is a vane pump, this pump has a large flow, low lift, high specific speed, high efficiency, small footprint, variable performance parameters, and suitable for low water conditions and other characteristics. Therefore, it often becomes the preferred type of pump for agricultural irrigation and drainage, urban water supply and drainage, and thermal power plant to transport circulating water.
First, the basic structure and role of the water flow from the suction pool, through the inhalation flare tube, impeller impeller impeller forced water rotation, so that water into the guide vane body, the energy conversion to produce head, through the pump cylinder from the drain bend Tube discharge. Pump through the coupling (rigid) and the intermediate shaft coupling. Bearings under the motor bearings bear all the downward axial force of the rotor. Intermediate shaft and motor shaft with a flexible coupling.
Axial flow pump impeller (hub body) with blades, depending on whether the adjustable pump performance parameters of the pump, axial flow pump is divided into the following three:
Fixed axial flow pump - impeller (hub body) and the blade as a whole structure, the blade is not adjustable;
Half Regulating Blade Axial Flow Pump - Combination of impeller (hub body) and blades is only possible when the machine is shut down. Remove the setting angle (0 °, ± 2 °, ± 4 °, ± 6 °, ± 8 °), the adjustment of its angle is cascade;
Fully adjustable vane axial pump - through a set of adjustment mechanism (mechanical or hydraulic), the pump can be manually operated, electric, computer control, etc., for stepless adjustment of the blade angle.
Second, the inflow of water and wet pit, dry pit installation Axial pumps (especially large pumps) on the intake runner type and size requirements are very strict, it directly affects the pump performance (such as pump efficiency, cavitation performance, etc.) Therefore must pass the formal design (design institute design).
Puddle installation means that the pump is submerged in whole or in part in the pumped liquid and the pump is partially submerged in the suction basin;
Dry pit installation, refers to the pump all surrounded by air, using elbow suction flow diversion into the pump.
Third, the installation of the pump base and discharge elbow outlet location Double basic installation: the pump installed in the foundation, the motor installed in the motor foundation (on the foundation). Pump axial force is borne by the bearings of the motor bearings, the basic load conditions of the pump operation:
Under the basal force = pump shell weight + pump shell water - pump axial water thrust motor base = motor weight + pump rotor weight + pump axial water thrust Single-base installation: pump and motor constitute a whole Direct Type structure, installed on the basis of the motor, the shaft and the motor shaft coupling with rigid coupling, pump operation based on the load situation:
Motor foundation (single-story foundation) Force = pump shell weight + pump rotor weight + motor weight + pump shell water weight Double-layer foundation Exhaust pipe Between two foundations, a single-story foundation can be set on top of the foundation as needed.
Fourth, the rotor can be withdrawn structure Rotor and pump body is usually "integrated" structure, the entire pump lifting necessary removal, in order to facilitate the maintenance, the rotor can be taken out of the structure. The rotor components (including the guide vanes) are withdrawn from the pump barrel and the discharge elbow, which avoids disassembly of the discharge pipelines and lightens the lifting weight.
Fifth, the lubrication of pump-guided bearings and shaft protection Water temperature lubrication, water-lubricated rubber bearings, available transport medium lubrication, pump shaft without protection device, conveying sandy water (such as the Yellow River water) or corrosive media Such as sea water), shaft and guide bearings, the use of protection (sets) of pipe protection, so that the media isolation, with water for lubrication.