QJB-W Sludge Recirculation Pump

Du'an Environmental Protection QJB-W Type Mixed Liquid Recirculation Pump Product Description:

1. Impeller

The propeller impeller should be capable of handling conventional sewage. The propeller impeller is hydraulically balanced in structural design, featuring a non-clogging and self-cleaning form. The propeller impeller should be meticulously processed and surface-treated to efficiently transmit the motor's output power. The impeller has three blades. All blades are of the same form and evenly spaced. The blades and hub must be made of stainless steel AISI316 or SU304. The propeller impeller is fixed to the end of the shaft with a single key bolt, sealed with a protective cap, and should use a locking washer system. The propeller impeller must pass dynamic balance inspection.

2. Gearbox

The mixed liquid recirculation pump is driven by a high-performance planetary gearbox. The gearbox housing and the through-wall pump casing should be integrated, streamlined, and conical, with a smooth transition between the surface, hub, and motor housing to ensure high stability and excellent hydraulic characteristics, improving the overall efficiency of the through-wall pump. The gearbox should be equipped with high-precision, high-efficiency, low-load single-stage planetary gears, with gear teeth made of high-wear-resistant alloy steel. The gearbox is filled with oil for lubrication and cooling, reducing the impact of leakage. The gearbox should be manufactured by internationally renowned specialized gearbox manufacturers. The design service life should not be less than 100,000 hours.

3. Shaft

The motor shaft and propeller shaft are connected via the gearbox. The shafts are made of wear-resistant stainless steel, and both the propeller shaft and motor shaft can withstand all axial and radial loads. The propeller shaft is fully protected by mechanical seals and radial seals, isolated from the medium.

4. Bearings

The motor shaft of the mixed liquid recirculation pump should rotate on two ball bearings, and the propeller shaft is supported by two tapered roller bearings.

All bearings are high-quality maintenance-free bearings with long-term grease lubrication, capable of withstanding axial and radial loads. The bearing life should exceed 100,000 hours.

5. Mechanical Seals

Two independent high-quality mechanical seal systems are used, one above and one below, allowing rotation in both clockwise and counterclockwise directions without adverse effects. The mechanical seals are made of tungsten carbide/tungsten carbide or silicon carbide/silicon carbide, suitable for a medium pH range of 6 to 10.

The mechanical seals should be maintenance-free, with lubrication separated from the conveyed liquid, resistant to thermal shock, and capable of emergency operation.

Between the two mechanical seals, there should be an oil chamber filled with paraffin oil that meets hygiene standards. The paraffin oil lubricates and cools the mechanical seals and acts as a buffer between the conveyed medium and the motor cavity for additional protection. The normal service life of the mechanical seals should be no less than 25,000 hours.

6. Motor

The motor should be a squirrel cage submersible motor, 3-phase, 380V, 50Hz, with protection class IP68 and insulation class F. The motor should be capable of starting 10 times per hour. It should be able to handle a pumping medium temperature of 40°C, with the average temperature rise of the stator windings not exceeding 80°C. The stator should be thermally pressed into the stator chamber, maintaining an appropriate gap with the rotor. The direct starting current should not exceed 6 times the rated current. The submersible motor and pump must be produced by the same manufacturer.

7. Cable and Cable Seal

The motor should be equipped with a submersible cable that includes both control and power cores. The cable should have a separate and reliable cable entry. The cable size should comply with IEC standards and provide sufficient length to connect to the junction box or local control cabinet without splicing. The cable entry into the terminal chamber should use a reusable double-compression rubber sleeve seal. Epoxy, silicone, or other secondary sealing systems should not be used. The cable should be replaceable, with the cable exit axially aligned and tightly arranged along the outer surface of the motor housing. The cable should be secured with cable clamps and tensioning steel cables to avoid movement due to water flow and prevent snagging during lifting.

8. Mixed Liquid Recirculation Pump Protection System

The mixed liquid recirculation pump should be equipped with a protection system to indicate issues such as clogging, overload, faults, and water leakage. It should send relevant signals before severe damage occurs to the motor or main shaft.

9. Motor Overload Protection

Each winding of the motor is protected by a PTC-type temperature sensor. The three sensors should be connected in series and activate at 125°C. All protection signals are converted into passive contacts through a combined module.

10. Motor Cavity Leakage Protection and Mechanical Seal Leakage Protection

A sensor is provided in the stator chamber to detect liquid leakage. It outputs a signal in case of seal leakage to prevent water from entering the motor cavity.

QJB-W Type Sludge Recirculation Pump Technical Description:  

The QJB-W type sludge recirculation pump is a new product developed based on submersible mixer production technology. This pump is a specialized equipment for mixed liquid recirculation and denitrification in secondary wastewater treatment plants. It can also be used for pumping purified water during surface drainage, irrigation, and control of water channel systems, as well as in recirculation during wastewater treatment or in slurry suction circuits requiring low head and high flow.

The QJB-W type sludge recirculation pump is equipped with a technically advanced axial-flow three-blade impeller, which features excellent self-cleaning and vibration-free functions. The impeller design meets the requirements for high flow and low head, generating high flow axially. It adopts Swedish Flygt submersible motor sealing technology to ensure safe and reliable sealing. When water enters the oil chamber, the humidity sensor in the leakage detection system will automatically send an alarm signal for timely detection and prevention of secondary failures. The motor windings of the QJB-W type submersible recirculation pump use the internationally advanced overheating protection process. In case of overheating due to motor overload, high medium temperature, or other reasons, the temperature sensor will send an alarm signal or automatically shut down the pump before the temperature exceeds the allowable limit.

The QJB-W type sludge recirculation pump is equipped with a single-guide rail automatic coupling system, ensuring quick installation, lifting, and maintenance. Developed based on the digestion and absorption of foreign similar product technologies, it features high efficiency, anti-clogging, non-clogging, automatic coupling, high reliability, and automatic control. It has unique functions in discharging solid particles and long-fiber debris. The QJB-W submersible recirculation pump is a self-developed product based on introduced German submersible motor production technology. It is a specialized equipment for mixed liquid recirculation and denitrification in secondary wastewater treatment plants and can also be used in applications requiring low head and high flow, such as surface drainage, irrigation, and recirculation during wastewater treatment.

The QJB-W type sludge recirculation pump offers low head, high flow, and high efficiency. The impeller has a high-performance hydraulic design structure, with swept-back blades featuring self-cleaning functions, anti-clogging, and anti-wrapping. It uses new sealing materials, two mechanical seals made of tungsten carbide–tungsten carbide, imported bearings, and all fasteners made of stainless steel, enabling safe and continuous operation for over 10,000 hours. The QJB-W type submersible recirculation pump has a compact structure, simple operation and maintenance, easy installation and repair, and a long service life. The main unit uses cast or stainless steel pressure-formed structure, with small size, high density, corrosion resistance, and no noise. It is equipped with protection and alarm devices for leakage, water leakage, and motor overload, ensuring product safety and reliability.

Jiangsu Du'an Environmental Protection Sludge Recirculation Pump Supply Scope:

Jiangsu Du'an Environmental Protection internal recirculation through-wall pump should be a complete set of equipment, including a local control box, stainless steel double guide rods, stainless steel lifting chains, cantilever, lifting hoist, through-wall pipe, flap valve, cable from the control box to the equipment, and other necessary accessories for safe operation.

Supply Scope (including but not limited to the following):

(1)  Fully assembled internal recirculation pump

(2)  Monitoring unit

(3)  Complete lifting device

(4)  At least 10m of submersible cable per pump

(5)  All connecting accessories, embedded anchor bolts, etc.

Du'an Environmental Protection Equipment (Jiangsu) Co., Ltd. After-Sales Service:

After-sales service is crucial for the company's business development and reputation, as well as an important step for the company's progress.

For users, it is a guarantee of product quality and peace of mind.

1. Adhere to the customer-first principle. All products produced by our company meet strict enterprise standards and national mechanical department standards.

2. Provide spare parts, installation, debugging, maintenance services, and technical training for relevant personnel according to customer needs or agreements.

3. For large-scale projects, organize production, testing, and inspection according to tender requirements and cooperate with on-site customer acceptance.

4. Strictly follow ISO9001 standards for the procurement of raw materials and components, as well as product production and inspection.

5. Under normal storage, transportation, maintenance, and usage conditions, if the product fails to function normally due to manufacturing quality issues, provide a three-guarantee service (warranty, return, exchange).

6. Provide necessary technical documents and product qualification certificates for出厂 products.

7. During the warranty period, if the equipment fails to meet specified technical parameters due to errors in the equipment or technical资料 provided by us when the user operates according to the relevant technical documentation, the user should immediately notify us. We will replace/repair the defective equipment or technical资料 within 24 hours of receiving written or telephone notice.

8. If damage or malfunction occurs due to improper use by the user or outside the warranty period, our company provides终身维修 services for the product.

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