Pneumatic Submersible Pump

Introduction to pneumatic submersible pump

The pneumatic submersible pump is ideal for pumping sewage in areas where methane or coal dust explosions pose a risk, and it finds widespread application in the underground working face of coal mines for transporting groundwater that contains solid particles like dirt, pulverized coal, and sediment. The impeller adopts a special design, has strong sewage discharge ability, will not be blocked by the inhalation of solid particles or fibers, and will not be damaged prematurely due to the intake of granular media. The whole machine has a simple structure and is convenient for movement, assembly, disassembly, and maintenance. It has the advantages of high efficiency, good performance, and low air consumption.

Features of the pneumatic submersible pump

1. Stepless speed regulation. As long as the throttle valve opening program is controlled, i.e., the gas flow is controlled, stepless speed regulation can be realized.

2. Reliable use, durability, not being affected by temperature and vibration, installation, operation, and simplicity.

3. It is equipped with a silencing device that has low noise, easy maintenance, and small wearing parts.

4. It has high starting torque and the ability to work at full speed almost instantaneously.

5. Strong adaptability. It is suitable for discharging clean water and turbid water (mud, mud, sand, and cinder water) and is light in weight.

Technical parameters of the pneumatic submersible pump

1. Phase: 5-35m (Double wind edge 5-50m)

2. Flow rate: 8-28 m3/h

3. The working air pressure: 3-6 kg/cm2

4. Air consumption: 3-4 m3/min

5. Rated speed: 4500 r/min

6. The diameter of the water wheel: 120mm

7. The inner diameter of the air inlet hose: 25min

8. The inner diameter of the drainage hose: 50min

9. Noise: ≤ 88db

Composition of the mine pneumatic submersible pump

The mine pneumatic submersible pump is composed of five parts: pneumatic motor, water pump, lubricator, pipe joint, and muffler.

1. Pneumatic motor part:

It is composed of a rotor, blades, cylinders, housings, upper and lower cylinder heads, bearing glands, top covers, etc. The rotor has four evenly distributed radial grooves with blades and a blowing hole on each of the upper and lower cylinder heads. When the air pump is started, the high air pressure blows the blades in the tank from the blowing hole, and at the same time, a large amount of high air pressure enters the cylinder from the main air duct, which pushes the blades and drives the rotor to rotate. There is a sealing cavity under the shell, and there is a sealing ring in the cavity to separate the gas and water. The sealing ring adopts spring sealing and uses the pressure of air and water to make the sealing ring rise inward and enhance the sealing effect.

2. Water pump part:

It is composed of a pump body, an impeller, a pump seat, etc. The impeller is installed on the rotor shaft, the impeller nut is tightened, the pump body and pump seat are installed, and the impeller is and the impeller is put into the water. The rotor drives the impeller to rotate, and under the action of centrifugal force, the water flow is pressed into the vortex of the pump body and discharged along the outlet pipe.

3. Lubricator part:

It is composed of an oil lubricator shell, an oil lubricator rod, an oil regulating valve core, etc. The lubricator is installed on the top cover, and the shell is filled with lubricating oil.

4. Pipe joint part:

It is composed of two parts: the air inlet combination joint and the water outlet elbow. The air inlet coupling is installed at the air inlet.

5. Muffler part:

The muffler is stamped and welded to a steel plate and installed at the exhaust port.

Precautions of the mine pneumatic submersible pump

1. The depth of the pump submerged underwater shall not exceed 0.40m.

2. The temperature of the conveying medium shall not exceed 40°C.

3. Working environment temperature (2~40) °C.

4. The PH of the conveying medium is in the range of 4~10.

5. The maximum diameter of solid particles shall not exceed 3mm, and the volume concentration shall not exceed 2%.

6. The compressed air for pump power should be in the range of (0.45~0.70) MPa, and can meet the requirements of air consumption.

Overview of the mine pneumatic submersible pump

mechanical product with a coaxial connection between the rotor and the pump body and adopts a vertical structure and a lower pump type.

The pneumatic submersible pump for mine is suitable for drainage operations in hazardous places containing gas and coal dust explosions and can be widely used in any working face of a coal mine to transport groundwater containing coal dust and sediment particles, which is safe and reliable to use and effectively improves the air quality on site.

Working environment of the mine pneumatic submersible pump

a) The surrounding air contains gas and coal dust;

b) The air pressure is (0.4~0.7) MPa;

c) The pH value of the water is in the range of 6~8;

d) The volume ratio of solid impurities in water does not exceed 2%;

e) Working environment temperature (5~40) quality.

Technical characteristics of the mine pneumatic submersible pump

The FQW50-25/W mining pneumatic submersible pump has a compact structure and is easy to move, assemble, disassemble, and maintain. The vortex of the pump body adopts a high-efficiency and energy-saving hydraulic model, and the impeller is specially designed. The pump has the advantages of a strong sewage discharge capacity, a large flow rate, and a high head.

The FQW50-25/W mining pneumatic submersible pump is mainly composed of three parts: pump body, air motor, and overflow.

1. Pump body part: divided into upper and lower chambers, separated by a sealing ring in the middle of the gas and water. The sealing ring is sealed by a spring, and the pressure of air and water is used to make the high-pressure gas and water enter the inner walls of the upper and lower sealing rings, respectively, so that they can rise inward and enhance the sealing effect.

 2. Air motor part: composed of rotor, turbine, bearing, etc. Powered by compressed air, the impact turbine pushes the rotor to run at high speed.

3. Flow part: It is composed of a water wheel, pump cover, suction port, pump seat, etc. The water wheel is installed on the rotor shaft of the lower cavity of the shell; the compressed air is sent from the air inlet; the rotor runs to drive the water wheel; and the water in the water wheel is pressed into the water vortex of the shell under the action of centrifugal force and discharged along the outlet pipe.

Safety precautions of the pneumatic submersible pump for mine

1. When there is no water, the air source should be turned off immediately, and the machine should be stopped!

2. The working air pressure shall not be greater than 0.70 MPa.

3. If a fault is found, it should be shut down and used after normal maintenance.

Transportation and storage of the mine pneumatic submersible pump

The product can be transported by conventional means of transport, and there should be reliable positioning and waterproof measures during transportation to prevent vibration and impact. It is strictly forbidden to load and unload barbarically and shall not be mixed with corrosive substances for transportation. The product shall be stored in a ventilated and dry warehouse in an upright position and shall not be stored in the same warehouse with corrosive substances.

Faults and troubleshooting methods of the mine pneumatic submersible pump

Symptom 1: Cannot be started

Cause of failure:

1. After the air pump is out of use, the rock powder in the water will precipitate, and the gap between the impeller and the pump cover will be blocked.

2. Due to the shutdown of wind and water, the water wheel is reversed, and the water wheel nut is loosened, so that the water wheel sinks and rubs against the pump cover, and it is difficult to start.

3. Rust or other impurities on the inner wall of the trachea enter the cylinder, and the impeller is stuck in the rotor groove and cannot be blown out.

Exclusion Method:

1. Open the pump cover, remove impurities, and make the water wheel run freely, which can be used.

2. Pad the spring washer and tighten the water wheel nut.

3. Open the cylinder and wash the rotor.

Phenomenon 2: The operation is normal, but the flow rate drops, the water does not rise, and the pump bubbles in the water.

Cause of failure: worn skeleton oil seal or loose seal of sealing ring

Exclusion method: open the air pump, replace the sealing ring spring, and tighten it.

Phenomenon 4: The noise of the exhaust pipe gradually decreases to disappear, and the operation of the air pump stops.

Cause of failure: The air pump runs for a long time, and a large amount of compressed air is discharged from the exhaust pipe after diffusion through the cylinder, which takes away the surrounding heat energy, freezes the inner wall of the exhaust pipe, and gradually blocks the exhaust pipe.

Elimination method: Hit the exhaust rubber tube with a hardwood stick to break the ice cube and blow it away or stop the air supply. Let it melt naturally before continuing to use it. (It is best to install a water removal device for compressed air.)

Phenomenon 5: The start-up operation is normal, but the flow rate and head are not large.

Cause of failure:

1. The air pressure is too low.

2. The filter hole on the anti-fouling cover (pump seat) is blocked, and the water absorption is insufficient.

Exclusion method:

1. Wait for the air pressure to rise to 0.6~0.7 MPa before continuing to use.

2. Clean the anti-fouling cover (pump seat) and use the holes unblocked.

Phenomenon 6: The pump body vibrates more during operation.

Cause of failure: bending of the rotor shaft or excessive bearing wear.

Exclusion method: Adjust the pump shaft or replace the bearing. 

Use, repair and maintenance of the mine pneumatic submersible pump

1. Before the new pump is used, it must be tested on the ground once. When running on the ground, the air pressure should be controlled within 0.2 MPa, and the test pump time should not exceed three minutes, so as to avoid high-speed operation, accelerate the wear of parts and components, and reduce the service life.

2. The inner diameter of the inlet pipe shall not be less than 25 mm, and the working air pressure shall not be less than 0.5 MPa; otherwise, it will affect the normal operation.

3. When installing the inlet pipe, the impurities in the pipe and the joints should be blown clean to ensure that the intake air is dry and clean, so as to avoid impurities from entering, causing parts to wear or the rotor to be stuck and unable to operate.

4. The water wheel nut must be added with a spring washer to prevent the rotor from reversing and loosening when the water is returned, causing friction between the impeller sinking and the pump body.

5. In the process of replacing the assembly and disassembly of wearing parts such as impellers, turbines, and sealing rings, it should not be struck with a heavy hammer so as not to damage the matching accuracy of internal parts. Generally, after about 15 days of continuous use, the air pump should be opened and cleaned once for maintenance.

6. The sewage air pump can be used in turbid water containing more rock silt and sediment and can pass through ≤ 10 mm particles, which will not be blocked by the inhalation of small solid particles or fibers and will not be damaged prematurely due to the intake of abrasive media.

7. The exhaust pipe should be exposed to the water surface, and no water or other impurities should be allowed into the exhaust pipe so as not to rust the internal parts of the cylinder or jam the impeller and rotor.