Duwan Environmental QJB7.5/4-2500/2-39/P Submersible Pump Propeller Technical Description

Installation Instructions for Submersible Propeller

Diving Propulsion CAD Installation Diagram

（1）DivingFlow Controller Construction

Low-speed submersionFlowmeter GearboxStructureThe design features a dive-sealed connection. All components of the propeller, including the motor and gear box, should be capable of continuous operation underwater. The primary components of the propeller that come into contact with liquid should be made of stainless steel. AISI 304. All nuts, bolts, and washers should be made of AISI 304 stainless steel or better. The oil chamber cover should be made of a corrosion-resistant synthetic material. On critical contact surfaces requiring waterproof sealing, use nitrile or fluorinated rubber O-rings to ensure tightness without the need for special torque restrictions on the rubber O-rings on both sides and the four sides of the O-rings' contact. Do not use forms that require a specific torque to achieve tightness, nor should rectangular section washers and sealing compounds be considered.

The flow diverter should be capable of handling raw and wastewater. The diverter is adjustable for up and down movement, allowing for easy relocation, inspection, or maintenance without the need for personnel to enter the wet well. The sliding rod bracket is one of the integral components of the diverter. All the weight of the diverter is supported by a single bracket, and this bracket must be able to withstand the thrust generated by the diverter.

All mechanical sealing surfaces should be made of corrosion-resistant tungsten carbide or better materials. The service life of the mechanical seal should not be less than 25,000 hours.

Flow controllers, their accessories, and cables should be capable of continuous immersion at greater depths. 20 meters underwater without losing its watertightness (compliant with IP68 protection rating).

（2) Propeller

The propeller should include two glass fiber reinforced polyurethane blades, each equipped with a stainless steel shaft mounted in a cast iron hub. The blades should haveFlexible and capable of absorbing varying hydraulic loads. Metal blades are not acceptable due to their lack of elasticity. Each blade should be mounted in a socket on the hub side and secured in place on the keyed propeller shaft to resist torque. The propeller shaft should be axially fixed to the hub and a locking washer system should be used.

The blade shape should be a non-blocking, swept design, starting from the hub, ensuring no part of the shaft is exposed. The propeller should be capable of handling particles, fibrous materials, heavy sewage, and other substances encountered in conventional wastewater treatment.

The propeller has passed dynamic balancing inspection.

（3) Gearbox

The gearbox should be a two-stage, cylindrical bevel gear box equipped with high-precision, low-load gears. The motor shaft should be fitted with an integrated drive gear. The intermediate shaft of the gearbox containing the first-stage drive gear should be closely matched with the drive gear of the motor shaft. The intermediate shaft should rotate in two roller bearings and contain a second-stage drive gear. The impeller shaft should include a second-stage drive gear and rotate in a single-row and a double-row angular contact ball bearing.

（4) Axle

Motor shaft and propeller shaft are connected through a gearbox; the shaft is made of stainless steel. 431 Manufacturing, propeller shafts and motor shafts can withstand all axial and radial loads. The propeller shaft is fully protected by mechanical seals and radial seals, isolated from the liquid.

（5) Bearings

The flowmeter motor shaft should rotate on two lubricated bearings. The inner bearing should be a single-row deep groove ball bearing, while the main bearing is a double-row roller bearing. All bearings are high-quality, maintenance-free bearings lubricated with long-lasting grease, capable of withstanding axial and radial loads. The design life of all bearings is at least 100,000 hours.

（6) Electric Motor

DivingThe motor of the flowmeter should be a squirrel-cage induction motor, installed in an inflated, waterproof housing. The stator windings and wires should be insulated to resist dampness, with an insulation grade of H Level (180°C), along with a colored printed product sample authenticated by the manufacturer's seal or other supporting documents.

Jiangsu Du'an Environmental Protection Submersible Propeller Model Specifications: 

Each Duwan Environmental QJB Submersible Thruster set is equipped with a local control box. The requirements for the on-site control box are as follows:

（1) In addition to the internal buttons and signal lights, 35 terminals are included.

（2) Order the converter for motor protection and the equipment together.

（3) The start/stop button should have two sets of contacts, and the stop button (with a mushroom head) should remain engaged when pressed.

（4) To ensure a seamless connection between the on-site control box and the entire factory's control system, the terminal blocks within the control box are fitted with Weidmüller products.

（5) With cable connector.

（6) Protection Rating: IP65.

（7) Reserve PLC interfaces; each device must be controlled at both the local control box and the central control room.

（8）Material of on-site control box: Outdoor use 304 Stainless steel, carbon steel coated for indoor use, cabinetColor selection is determined by Blue Deep Group.

（9) Components in the control box are of ABB, Schneider, Siemens, or equivalent brands.

Duwan Environmental QJB Submersible Flow PropellerInstallationDescription

Duwan Environmental ProtectionDiving Propulsion DeviceInstall strictly according to the manufacturer's instructions and suggestions at the locations specified in the drawings. Additionally, provide the lubricants required for the operation during the warranty period as recommended by the manufacturer. The foundation bolts are to be supplied and installed by the supplier, and they must meet the manufacturer's requirements.