Submersible sand sucking machines and submersible sewage pumps are two types of slurry pumps widely used in engineering, agriculture, environmental protection and other fields. They have high value in practical applications and can effectively solve the transportation problems of sand, mud and other materials. Although there are some functional similarities between the two, there are still significant differences between them. This article will introduce these two devices in detail to help everyone better understand their characteristics and differences.

1.Different Concepts Between Submersible Sucking Machines and Submersible Sewage Pump

1.What is Submersible Sucking Machine

Submersible sand sucking machine, also known as submersible sand dredge pump or submersible slurry pump, is a pump equipment designed to extract sand or mud mixed water from underwater sources. This type of submersible sand sucking machine is designed to handle abrasive materials and transport them over long distances to a designated location. In fields such as construction, mining, and dredging, submersible sand sucking machines play an important role in promoting operations such as sand mining, underwater excavation, or land reclamation. It has the ability to handle high concentrations of solid particles and is designed for durability and corrosion resistance.
The submersible sand sucking machines produced by OCEAN Pump use durable materials and components to effectively resist the abrasion of the pumped materials. Equipment is often equipped with suction tips or dredging attachments to enhance the extraction process. During operation, the pump body is immersed in water, enabling efficient removal of sand and mud from underwater sources.

2.What is Submersible Sewage Pump

A submersible sewage pump is a type of pump specifically designed for pumping sewage or wastewater containing solids, organic matter, and other debris. It is used in applications where efficient transport of sewage or wastewater is required, such as municipal sewage systems, wastewater treatment plants, industrial facilities, and residential buildings.Unlike other types of pumps, submersible sewage pumps are designed to be submerged in the sewage or wastewater they are pumping. This submersion allows for effective and efficient pumping without the need for priming or external assistance.
submersible sewage pumps are specialized pumps designed for efficiently pumping sewage or wastewater containing solids and debris. They play a crucial role in sewage systems and wastewater treatment plants, contributing to the effective management and transport of wastewater in various industrial, commercial, and residential settings.

The key distinction between submersible sand sucking machines and submersible sewage pumps lies in the product standards. Product standards define the type, variety, and structure of sand pump machines, and specify the main technical performance indicators. However, since there is no industry standard in place, there is no clear or uniform definition of submersible sand sucking machines. This lack of standardization has led to confusion in the market for submersible sand sucking machines.

The lifespan of a submersible sand sucking machine varies greatly depending on the composition and concentration of the sand slurry. To address this, a unified standard should be developed to specify the composition, concentration, density, viscosity, and other parameters of standard mortar. This standard should also define a submersible sand sucking machine as one that can operate normally for a specific duration in standard mortar.

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2. Different Working Conditions of Submersible Sucking Machines and Submersible Sewage Pump

1. The Difference Conveyed Medium of Submersible Sand Sucking Machine and Submersible Sewage Pump

The submersible sewage pump is designed to pump treated domestic wastewater (sewage) with a permissible non-abrasive solid content of up to 4%. On the other hand, the submersible sand sucking machine is specifically designed for pumping water rich in mud and sand. According to product standards, this equipment is suitable for conveying liquids containing suspended solid particles such as quartz sand, ore, rock, ash, coal, and crushed stone. The maximum permissible density of the conveyed slurry is divided into three levels.
1. In low concentration conditions, the density does not exceed 1100 kg/m3. It is primarily used in coal mining areas for conveying media containing coal slurry and crushed coal. The highest allowable concentration (specific gravity) is: fine coal slurry 29%, tailings slurry 20%, quartz sand 15%, tailings 13%.
2. In high concentration conditions, the density does not exceed 1300 kg/m3. It is mainly used for slurry transportation in industrial processes or rock blasting construction drainage without specific control measures for sand content. The highest allowable concentration (specific gravity) is: refined coal slurry and tailings 40%, quartz sand 37%, tailings sand 33%.
3. In ultra-high concentration conditions, the density does not exceed 1500 kg/m3. It is primarily used for professional sand mining, tailings sand transportation, or slurry transportation without specific control measures for sand content. The highest allowable concentration (specific gravity) is: fine coal slurry, tailings slurry 60%, yellow clay 40%, quartz sand 54%, tailings sand 48%, iron concentrate 42%.

Note: Specific gravities: iron concentrate 4.9, tailings sand 3.3, quartz sand 2.65, yellow clay 2.6, tailings slurry 1.8, refined coal slurry 1.45. The selection of other medium models is based on the reference parameters of slurry density and solid specific gravity mentioned above.

2.The difference matching motor power of Submersible Sand Sucking Machine and Submersible Sewage Pump

The power output of a pump, P, is given by the equation P = ρgQH, where ρ is the density of the conveyed slurry, g is the acceleration due to gravity, Q is the pump flow rate, and H is the pump head.
The matching motor for a submersible sewage pump is designed based on the standard for clear water with a density of 1000 kg/m3. However, when the submersible sewage pump is used to extract impurities such as mud and sand, the motor can be overloaded and burn out. It is important to note that there is a significant difference between the theoretically calculated power output of the pump and the actual power output. The calculation of the motor power for a submersible sand sucking machine is not simply the product of the motor power of a similarly sized submersible sewage pump and the slurry density. Instead, an additional margin of 1.3 to 2 times should be added on top of that.

During the operation of a submersible sand sucking machine, it is difficult to control the mud concentration, and fluctuations in the density of the conveyed slurry directly affect the output power of the sand suction pump. Additionally, when a submersible sand sucking machine starts running, solid particles can hinder the rotation of the impeller (and even lead to impeller blockage in severe cases), further increasing the output power requirements of the sand suction pump. The larger the particle size, the more pronounced this uncertainty factor becomes. Therefore, when designing and matching the motor power for a submersible sand sucking machine, it is necessary to consider both the rated output power and the maximum output power of the sand suction pump to ensure stable motor operation.

The matching motor for a submersible sand sucking machine takes into account the mud density and also includes an additional margin. Furthermore, a forced water cooling structure (such as a double-layer motor casing or an external water guide sleeve) is employed. By slightly increasing the cost, the motor power can be significantly improved.

The following are the test measurement results from the national testing center:

The Y series 4 kW motor, with a forced water cooling structure, can pass the 5.5 kW motor test, increasing the power by 1.38 times.

The Y series 55 kW motor, with a forced water cooling structure, can pass the 82.5 kW motor test, increasing the power by 1.5 times.

The Y series 1.1 kW motor, with a forced water cooling structure, can pass the 2.2 kW motor test, doubling the power.

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3. Different structural characteristics Between Submersible Sand Sucking Machine and Submersible Sewage Pump

In the case of submersible sewage pumps, the main issues that can lead to damage are motor burnout and impeller wear when the water being pumped contains sand and mud. Motor burnout is often caused by overload, which can potentially be addressed by increasing the power of the matching motor or implementing a forced water-cooling structure, as discussed earlier. Water ingress into the motor, on the other hand, is a problem associated with sand discharge and sealing, which requires further scientific research for effective solutions.

To enhance the service life of submersible sand sucking machines, it is crucial to address sealing and wear-related challenges, with a primary focus on sealing. OCEAN PUMP provides a sealing solution that incorporates the following measures:

1.Air seal structure: The motor shaft extension end is separated from the mortar, minimizing the risk of water entering the motor.

2.Specially designed double-end hard alloy mechanical seal: This improves the reliability of the mechanical seal. The machine seal utilizes oil lubrication, and a significant amount of oil is present in the machine seal cavity to prevent slurry from infiltrating.

3.Independent connection room: A separate connection room exists between the mechanical seal cavity and the bearing room, featuring a passage to the water storage room. In the event of mechanical seal failure, any small amount of leaked slurry will flow into the water storage chamber instead of contacting the bearing. This design prevents bearing grease loss and extends bearing lifespan.

4.Closed motor cavity: The motor operates within a closed cavity. If high temperatures generate excessive pressure, a safety valve allows the slurry in the water storage chamber or oil storage chamber to escape.

5.High winding position: The motor winding is positioned relatively high within the motor cavity. Even if water enters the cavity, it will not directly contact the winding. This structure prolongs the motor’s lifespan. Additionally, the motor possesses a high insulation level and exhibits strong resistance to dampness and heat, further enhancing its longevity. During humidity and heat resistance tests, the vertical submersible sand sucking machine motor undergoes testing without the O-rings, while other submersible motor machines are subjected to sealed tests during certification inspection. This ensures that the submersible motor is evaluated in a simulated usage state, replicating actual conditions. Otherwise, the humidity and heat resistance test of the submersible motor would be meaningless.

By implementing these sealing solutions and motor protection measures, the submersible sand sucking machine can achieve improved durability and reliability in handling sand, mud, and slurry-laden water.

OCEAN PUMP has developed effective solutions to address wear and tear in submersible sand sucking machines. These solutions aim to extend the machine’s lifespan while considering a slight increase in cost. The following measures have been implemented:

1. Improved Mouth Ring Material: By enhancing the material used in the mouth ring, the submersible sand sucking machine’s durability is significantly increased. This improvement helps withstand the abrasive effects of sand and mud, ensuring a longer operational life.

2. Space Guide Vane Structure: The adoption of a space guide vane structure allows for the prevention of effective circular movement of sand and mud. This design is more resistant to wear compared to traditional volute structures and provides a longer service life.

3. Low Specific Speed Impeller with Herringbone Blades: The impeller with a low specific speed is equipped with herringbone blades. This design optimizes the narrow flow channel by increasing the vertical and horizontal distances between the impeller and the submersible sand sucking machine casing. By reducing the flow channel length, the sediment passage performance is improved, the flow rate is controlled, and the wear between sand and the flow channel wall is minimized.

4. Strengthened Vulnerable Parts: The vulnerable parts of the impeller and mud pump body are reinforced to enhance their durability. Additionally, wear-resistant materials are utilized, and alloy linings are added to increase their resistance to wear.

Through these measures, OCEAN PUMP has effectively addressed wear and tear concerns in submersible sand sucking machines, resulting in improved performance, reduced maintenance needs, and extended operational lifespans.

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4. Different Safety Performance Between Submersible Sand Sucking Machine and Submersible Sewage Pump

The submersible sewage pump with dry motor structure has the hidden danger of motor explosion when working. Therefore, we should take the corresponding measures to solve the safety problem for submersible sand sucking machine.

To address the safety concerns associated with the submersible sand sucking machine’s motor, OCEAN PUMP offers the following solutions:

1. Enhancing Motor Shell Strength: OCEAN PUMP welds the motor shell components, including the upper cover, casing, and lower cover, to improve the overall strength of the mud pump shell.

2. Rigorous Strength Testing: The motor shell of the submersible sand sucking machine undergoes a strength test with a minimum water pressure of 2.5 MPa (exceeding the 1 MPa requirement for certification inspections) and can withstand a maximum pressure of up to 9 MPa. The design of the motor shell strength and bolt specifications adheres to this standard.

3.Condensed Water Storage Chamber: The motor shell of the submersible sand sucking machine is equipped with a “storage chamber” to collect and store condensed water. This feature helps prevent the generation of high-temperature steam within the motor cavity.

It is crucial for users to differentiate between the submersible sand sucking machine and the submersible sewage pump, as they are distinct products. When selecting a model or making a purchase, careful consideration should be given to this distinction.

5.About OCEAN Pump

Tai’an Ocean Pump Co., Ltd. is a reputable manufacturer and supplier of high-quality submersible sand pumps, sand pumps, slurry pumps, heavy-duty marine sand pumps, and sand dredgers. With comprehensive capabilities in independent research and development, equipment manufacturing, pre-sales, and after-sales services, OCEAN PUMP has a dedicated technical team that has been actively involved in the development, matching, and application of sand pump machinery for various purposes, such as river dredging, sea reclamation, and tailings treatment since the 1990s.

Backed by extensive experience, excellent technology, and attentive service, OCEAN PUMP has gained the trust of its users. With a focus on sand pump equipment for over 20 years, OCEAN PUMP not only provides high-quality equipment and comprehensive solutions to the industry but also offers on-site installation services. For any inquiries related to dredging and sand suction, including plan design and equipment-related matters, please don’t hesitate to contact us.

Tai’an Ocean Pump Co.,Ltd

Mobile/Whatsapp/Wechat: +86 18562293317

Email: sales@slurrypumpdm.com

Website: www.slurrypumpdm.com