QJB2.5/8-400/3-740S

Submersible mixer installation method

QJB-Submersible Mixing Pump, Non-Draining Installation

Jiangsu Du'an Environmental Protection QJB2.5/8-400/3-740S Submersible Mixers Performance and Structure

1. Structure

（1）QJB2.5/8-400/3-740SSubmersible mixer construction

Each mixer should be designed as a whole unit, with sealed connections and submersible type. All components of the mixer, including the motor and gear box, should be capable of continuous operation underwater. The mixer propeller is driven by a submersible motor through a reduction gear. The rotating head is streamlined cone-shaped, with a compact structure.

除了 the shaft and blades, the main components of the stirrer that come into contact with the liquid should be gray cast iron, ASTM standard.A48 Class 35B, or DIN 1691 GG25, surface is smooth, free of sand holes, blow holes, or other defects. The shell thickness should be sufficient to withstand water pressure and other loads.

All nuts, bolts, and washers should be made of AISI316 stainless steel or better.

Submersible mixers should have machined surfaces on critical contact surfaces requiring water-tight seals, utilizing metal and...Metal contact, with nitrile or fluoroelastomer rubber O Retaining rings, cannot use those requiring a certain torque to achieve a clamping effect, and gaskets made of rubber, paper, or chemical compounds with a rectangular cross-section. Do not use secondary sealing compounds, oval sealing rings, wool, or other devices.

All cast iron surfaces on the external parts of the submersible agitator that come into contact with liquids should be coated with an epoxy resin for protection.

DivingMixers, their accessories, and cables should be capable of continuous immersion at great depths. 20 It remains watertight underwater without any loss.

Propeller

Propellers should be capable of handling regular sewage. All propellers are hydraulically balanced, non-tangled, and self-cleaning in design. Propellers should be carefully machined and surface treated. Propellers efficiently transfer the motor's output power for mixing and propelling the flow of sewage at the pool bottom.

All blades of the propeller are of the same form, evenly spaced. The material of the blades should beStainless Steel AISI 304, the blade and hub are firmly integrated into a single unit, secured with a single key bolt at the end of the shaft, sealed with a protective cap, and a locking washer system should be used.

The propeller has passed dynamic balance testing.

(3) Gearbox

Submersible mixers must be driven by an effective planetary gear box. The gear box housing and the mixer housing should be integrated, forming a streamlined conical shape, with a smooth transition to the hub and motor housing to ensure high stability and excellent hydraulic characteristics, thereby enhancing the overall efficiency of the mixer. The gear box should be equipped with a single-planet gear with precision, efficiency, and low load, made of wear-resistant alloy steel. The gear box is filled with oil for lubrication and cooling, and to minimize the impact of leakage.

The gearbox should be manufactured by a renowned domestic transmission specialist. The design lifespan should not be less than 100,000 hours.

(4) Axle

The motor shaft and propeller shaft are connected through a gearbox. The shaft is made of wear-resistant stainless steel, capable of withstanding all axial and radial loads. The propeller shaft is fully protected by mechanical and radial seals, isolated from the medium.

(5) Bearings

The propeller shaft of the submersible mixer motor should rotate on two ball bearings, with the propeller shaft supported by two cone roller bearings. All bearings are high-quality, maintenance-free units lubricated with grease, capable of withstanding both axial and radial loads.

Bearings are 0.5Qn< Qn<1.25Qn Operating within the scope（Qn For operating condition）Bearings lifespanLife should be 100，000 Over 24 hours.

(6) Electric Motor

The潜水 motor should be a three-phase squirrel-cage induction motor. The motor's protection grade is IEC IP68 ratingInsulation grade: F Grade, 155°C. Appropriate rated power should be ensured to prevent the agitator from overheating during operation.Overload occurred. The motor should be capable of starting every hour. 20 The motor shaft and rotor have passed dynamic and static balancing tests.

The motor should be designed to operate in an environment of 40℃ (104°F), capable of immersion and continuous stirring of a liquid at 40℃, with the average temperature rise of the stator windings not exceeding 80℃.

Motors and cables must be capable of continuous operation at a depth of 20 meters without losing their waterproofing properties.Compliant IP68 Ingress Protection (IP) Rating）。

Submersible motors should be adequately cooled by the surrounding agitating medium; they should not rely on cooling jackets or external cooling.The system should be insulated. Moreover, the motor room should be filled with insulating oil to ensure excellent insulation and cooling properties, and to prevent leakage from damaging the motor.

To monitor the temperature on each phase winding, a thermal switch should be installed in each phase stator winding. The thermal switch is set to activate at 130°C and is connected to the control cabinet, interfacing with the control relay.

(7) Mechanical Seals

A mechanical seal and two radial seal rings should be installed between the impeller and the gear box of the submersible mixer. The radial seal rings are placed on a bronze sleeve, providing additional protection for the mechanical seal and should be easy to replace. The shaft seal system should include a sealing oil chamber, with the mechanical seal operating within it. A pair of radial seal rings should also be installed between the motor room and the gear box.

The mechanical seal should be maintenance-free and can rotate clockwise or counterclockwise without affecting or losing its sealing function. The mechanical seal is made of silicon carbide material, featuring good mechanical strength and resistance to thermal shock. The pH range of the medium should be between 4 and 10.

The design lifespan of the mechanical seal should exceed 25,000 hours.

(8) Cables and Cable Seals

The motor should be equipped with a submersible cable, which should be a single cable including both control and power cores.Equipped with a separate and reliable cable import. The cable dimensions should comply with IEC Standard with sufficient length for connection to junction boxes or local control cabinets without splicing. The cable entry to the junction room should be sealed with reusable double-track compression rubber sleeves, not with epoxy, silicone resin, or other secondary sealing systems, ensuring cable replacement. The cable outlet is axial, flush with the external surface of the motor housing.Arrangement, and secure the cables to the lifting chain using cable clamps to prevent them from swaying due to water flow impact, without getting snagged during hoisting.

(9) Motor Protection

Thermal sensor: All mixers are equipped with a three-phase stator coil. 3 Thermally activated switch, non-series connection

(PTO), used for monitoring stator temperature rise. The thermal protection should trip at 130°C, activating the alarm device and stopping the motor.

Leakage Sensors: All mixers should be equipped with leakage sensors to detect motor leaks, preventing water from entering and causing damage. The leakage sensors should be electrode-type sensors, with signals that can be monitored and an alarm signal triggered when water intrusion occurs.

Duwan Environmental QJB2.5/8-400/3-740S Submersible Mixing Pump Protection Relay should accept the alarm signal from the leakage sensor and output a fault trip contact to automatically cut off the motor power and stop the motor. The protection relay is installed onWithin the on-site control box, its power requirements are: AC220VThe relay protector should be provided with the stirrer as a matching accessory.

Each complete diving thruster assembly consists of a diving motor, a sealed gear reducer box, shaft, propeller, bracket, guide rod, etc. It should be supplied with the necessary accessories, fasteners, spare parts, and protective equipment for safe, effective, and reliable operation.Equipment, on-site control boxes and junction boxes, as well as required cables, a set of lifting device（Portable lifting brackets, lifting pulleys, stainless steel lifting chains, and shackles, etc.）Each set primarily includes the following components:

Fully Assembled Diving EquipmentStreaming Device

(2) Accompanying diving motorGearbox reducer

（3) Complete Installation System（Guides, brackets, cable tensioners, etc.）；

(4) Submersible cable for each streamer

(5) Electrical protection components, including short-circuit, overload, and phase-loss protection;

(6) Flow protector components include humidity protection, temperature protection, and protection controllers, etc.

(7) Local control cabinets and junction boxes, etc.

(8) All connecting accessories, all fasteners required for installation (including stainless steel chemical anchor bolts, nuts, washers, etc.).

(9) Two years of spare parts and tools.

Process Conditions

Installation Location:

Underwater medium in the hypoxic zone of the bio-reactor: Inside the bio-reactor

Wastewater medium temperature: 8～35℃; medium pH: 5～9

Ambient Temperature: -10℃ to 45℃

Operation mode: Intermittent operation or 24/7 continuous running.

Two-year warranty

Provide installation and debugging guidance