Submersible Pump With EX Motor for Mine
What is a submersible pump with EX motor for mine?
A submersible pump with EX motor for mine is a device with an explosion-proof motor, otherwise called EX motor, designed to operate below the surface of the pumped liquid. The EX-motor is hermetically sealed and close-coupled to the pump’s body. The pump manufacturers create the motor with safety features in line with the EX requirements to keep the environment safe. The explosion-proof design makes the submersible pump with EX motor for mine suitable for use in potentially hazardous locations, such as places with high humidity, extreme temperatures, or dust in the air that may ignite under certain conditions. Therefore, it is perfect for coal mining, chemical processing, the petrochemical industry, municipal engineering, etc. The submersible pump with EX motor for mine provides excellent performance parameters, including a high pump capacity (up to 4000 cubic meters per hour), a maximum pressure head of 200 meters, and a broader range of depths (70 meters maximum).
Figure: Submersible pump with EX motor for mine.
Components of a submersible pump with EX motor for mine
submersible motor
The submersible motor provides the power required to run the pump. It can be powered using direct current (DC) or alternating current. In a submersible pump with EX motor for mine, the submersible motor is usually hermetically sealed and close-couped to the pump head.
Casing
The pump casing houses the pump’s internal component helps to convert the fluid kinetic energy into a pressure head, and directs the fluid into the discharge connections. The pump casing features high-grade materials such as cast iron, ductile cast iron, stainless steel, etc.
Shaft
The shaft is a rotary stainless steel solid component centrally located in the pump and supported on bearings. Its primary function is to support the pump impeller.
Impeller
The impeller is the main rotating component in the submersible pump with EX motor for mine construction, whose function is to transfer the energy from the pump’s motor to the fluid. The impeller consists of a series of backward curved vanes that come off an open inlet at the center, known as the eye, which creates a centrifugal force as they spin to move the liquid from the casing to the discharge point. Submersible pump with EX motor pump’ manufacturers designs the impeller from different materials, such as cast iron, steel, etc.
Bearings
The primary purpose of the bearings is to support the rotor and to align them correctly with the fixed ends under the action of radial and axial forces. The submersible pump with EX motor for mine employs rolling ball bearings to contain the relative motion of the rotor assembly.
Suction inlet and discharge outlet
The fluid enters the submersible pump with EX motor for mine through the suction inlet and exits through the discharge outlet.
Mechanical seals
The mechanical seals create a water-tight barrier that helps to reduce leakage between the rotating shaft and the stationary pump casing.
Figure: Components of a submersible pump with EX motor for mine
How does a submersible pump with EX motor for mine operate?
When the pump starts, the shaft rotates the impeller at the same RPM as the motor. The centrifugal force acting on the impeller causes the pumped liquid pre-filled between the blades to rotate, creating a vacuum at the impeller’s eye, which allows more fluid to enter the pump. As the liquid turns, it moves radially and axially outwards until it enters the volute chamber at a very high velocity. In the volute chamber, some kinetic energy converts into a high static pressure head, allowing the liquid to rise to the surface and discharge to the desired height through the delivery connections.
Types of submersible pumps with EX motor for mine
Single suction submersible pump with EX motor for mine
In a single suction submersible pump with EX motor for mine, the fluid enters the impeller from one side and exits from the other. The single suction type provides a smooth operation and is easy to repair.
Figure: Single suction submersible pump with EX motor for mine.
Double suction submersible pump with EX motor for mine
In the double suction type of submersible pump with EX motor for mine, the pumping fluid enters either side of the impeller and exits from the middle section. As the liquid enters from both sides of the double suction impeller, the axial thrusts on either side effectively cancel out. Therefore, the double suction design can manage higher flows than the single suction because it is free or axial forces on the impeller. This pump is also less prone to wear and tear caused by an axial thrust; therefore, it can last longer than the single suction type. The double suction impeller also causes a reduction of inlet flow, making the pump less likely to experience cavitation.
Figure: Double suction submersible pump with EX motor for mine.
Single-stage submersible pump with EX motor for mine
The single stage submersible pump with EX motor for mine has only one impeller to impart motion to the fluid. The submersible pump with EX motor for mine manufacture can avail the single stage type with either single suction or double suction impeller. The single-stage type is the most uncomplicated design of submersible pumps with EX-motor for mine and is inexpensive.
Figure: Single-stage submersible pump with EX motor for mine.
Multistage submersible pumps with EX motor for mine
The submersible pump with EX motor for mine manufacturers may develop the pump in multistage design with an axial flow impeller, helping to push the fluid along the axis of the shaft. The multistage type of submersible pump with EX motor for mine consists of more than one impeller, providing the functionality of several pumps arranged in series. The multistage version of a submersible pump with EX motor for mine can generate higher fluid pressure than the single-stage counterpart. It is also less likely to experience leakage because the pressure head per stage is less.
Figure: Double suction submersible pump with EX motor for mine.
Applications of submersible pumps with EX motor for mine
The submersible pump with EX motor for mine manufacturers designs the edge cutting units to cater to mining operations mainly. However, they handle many other industrial pumping applications, including chemical processing, petrochemical, municipal engineering, gas and oil refineries, and hospitals. Submersible pumps with EX motor for mine find the following typical uses:
- They are used for drainage or pumping operations in coal mines and similar work environments under an explosive atmosphere where dangerous combustible gases, vapors, or flammable liquids exist.
- Submersible pumps with EX motor for mine also apply to coal mine roadway and mining working face.
- They are used in inland and offshore oil wells to pump crude oil from deep underground to treatment or holding facilities above the ground.
- They drain shallow water in the working grounds of coal mines.
- They are also used for emergency operations and disaster relief.
- They are used in water treatment plants where explosive gases are often a byproduct of the water treatment process.
Advantages of a submersible pump with EX motor for mine
- Submersible pumps with EX motors for mines eliminate the risk of explosion in explosive and hazardous locations, such as coal mines, oil and gas refineries, etc.
- The explosion-proof motor or EX-motor makes the pump very safe for the operator and the working environment.
- They have compact designs, making them easy to install and operate.
- The pump is self-priming because it is submerged in the pumped fluid; hence it eliminates manual primping cycles, which may be time-consuming.
- They have minimal maintenance requirements, thus, offering low life cycle costs.
- They are highly energy efficient because they do not require power to suck the pumped liquid into the pump casing.
- They provide an effective solution for applications requiring the supply of large quantities of liquid at a wide range of flow rates.
- They are highly reliable in pumping operations.
- They are usually quiet in operation since they sit in the pumped liquid.
Disadvantages of a submersible pump with EX motor for mine
- submersible pumps with EX motor for mine may are usually located deep underground and can be challenging to access. Therefore, the pumps may operate for a long time without regular inspection.
- They are relatively more expensive than the surface pump because the submersible design is much more technical and complex.
- They may also leak or fail due to weary gaskets.
- The pump is vulnerable to corrosion in submerged conditions.
Troubleshooting a submersible pump with EX motor for mine
The motor fails to start
- The motor is damaged. Disassemble the prime mover and inspect the windings and internal connections. If there are burn marks, the pump’s motor is likely blown out and requires changing.
- There is a fault in the motor wiring. Ensure the power cables connect correctly following the submersible pump with EX motor for mine manufacturer’s manual.
- The circuit breaker is tipped or fuse blown-out fuse. Reset the circuit breaker and replace the fuse if it is necessary.
- The centrifugal fuse or capacitor has failed. Consult a qualified technologist to inspect the fuse or capacitor and replace them if necessary.
The pump’s motor overheats
- The motor is defective. Inspect the motor conditions, repair any fault, or replace it if needed.
- There is a voltage spike due to a storm or lightning strike. Fit an external surge protection device to the submersible pump with EX motor for mine.
- The pump is partly submerged in the fluid. Ensure that the pump operates below the surface of the pumped liquid.
The pump gives little or no discharge
- The motor is running in reverse. Be sure to reverse the motor polarities. Check that the motor rotation direction matches the direction indicated by the submersible pump with EX motor manufacturer.
- The impeller is clogged. Clean the pump inside and remove any clogging material from the impeller.
- The submersible pump with EX motor for mine has excessive clearance leading to fluid recirculation. Ensure that the impeller is of the proper size.
- The discharge pipe is blocked. Disconnect the discharge line, and clean any blockage.
The pump does not develop pressure
- There is a leakage in the mechanical seals. Inspect and replace mechanical seals if needed.
- The discharge line is closed, preventing the priming air from exiting the pump. Open the discharge line.
- There is leakage in the foot valve or check valve. Inspect the conditions of the valves and replace them if need be.
The pump’s flow rate is unstable
- The power supply is insufficient. Inspect the level of the voltage supply and adjust it accordingly.
- The impeller or seal ring is worn-out. Inspect the impeller or seal ring for wear and replace them if you find it fit.
- The is a leakage in the bottom valve. Inspect the bottom valve for leakage and correct or replace it if necessary.
Summary
A submersible pump with EX motor for mine contains explosion-proof motor (also called EX motor) and is designed to be fully submerged in the pumped liquid. The pump manufacturers develop the explosion-proof motor to include safety features stipulated in EX requirements to keep the environment safe. The explosion-proof design makes the submersible pump with EX motor for mine excellent for potentially hazardous applications, such as locations with high humidity, extreme temperatures, or dust in the air that may ignite or explode under certain conditions. Therefore, a submersible pump with EX motor for mining is perfect for coal mining, chemical processing, the petrochemical industry, and other worksites in an explosive environment. Submersible pump with EX motor for mine’s manufacturers avails the edge-cutting units in different designs to fit different application demands. A submersible pump with EX motor for mine is safe to use, self-priming, highly efficient, and reliable.