Coal mine roots blower
Constant Air Volume / High Pressure: Positive air supply ensures stable airflow even with fluctuating resistance, suitable for long-term, high back-pressure conditions.
Durable and Robust: Made of heavy cast iron and solid steel rotor, resistant to dust, vibration, and wear, capable of 24-hour continuous operation.
Explosion-Proof Safety: Explosion-proof certification for coal mines and electrical systems.
Low Operation and Maintenance: Simple structure, low failure rate, and low long-term operating costs.
Application Scenarios
1. Underground Ventilation and Safety (Basic Applications)
Main Roadway Ventilation: Transporting fresh air over long distances (1000-3000 meters), removing gas, carbon dioxide, and dust to prevent accumulation and oxygen deficiency; air pressure 120-150 kPa, airflow 100-200 m³/min, ensuring uniform speed with no dead spots.
Local Face Ventilation: Short-distance mobile ventilation (≤500m), rapidly diluting harmful gases and dust after blasting; gas concentration can drop from 0.8% to 0.05% within 30 minutes.
Gas Extraction and Monitoring: Transporting low-concentration gases to reduce explosion risk; Ex d I Mb explosion-proof type for coal mines, preventing spark escape.
Dust Control: Combining wet dust removal to reduce underground dust concentration and prevent pneumoconiosis.
2. Mineral Processing and Coal Washing
Flotation Air Supply: Providing stable airflow for coal/non-ferrous metal flotation, mixing slurry and attached mineral particles, improving concentrate recovery.
Dry separation and air classification: Using air to separate ore and waste rock, increasing grade; suitable for high dust and high resistance conditions.
Slurry agitation and transport: Providing airflow to agitate slurry to prevent sedimentation; transporting waste and slurry, aiding in solid-liquid separation.
Dewatering/drying of coal preparation plant: Using airflow to remove water and dry coal slurry, reducing moisture and improving coal quality.
Roots blower is a type of positive displacement fan, characterized by two three-lobe impellers rotating opposite each other in a closed space formed by the casing and end plates. Since each impeller uses a casing or housing with external contours, the blades of each impeller are exactly identical, and the two impellers are also identical, greatly reducing processing difficulty. CNC equipment is used during impeller processing, ensuring that no matter where the two impellers rotate, with the center distance unchanged, the minimum gap can be maintained, thereby ensuring gas leakage within the allowable range.
The two rotors rotate facing each other. Because the gaps between the rotors, between the rotors and the casing, and between the rotors and the wall panels are extremely small, the intake chamber forms a vacuum state. Under atmospheric pressure, air enters the intake chamber. Then, the two blades of each rotor, together with the wall panel and casing, form a sealing chamber. As the rotor rotates, the air in the intake chamber is continuously transported by the two blades to the exhaust chamber. Because the rotors are inside the exhaust chamber grid, the air is compressed between the two blades. With this continuous process, air is constantly conveyed from the inlet to the outlet—this is the entire working process of a Roots blower.
Features
Thanks to the use of a three-lobe rotor structure and a well-designed inlet and outlet structure inside the casing, the blower has low vibration and low noise.
The rotor and shaft are an integral structure without keyways, ensuring that the blower performance remains unchanged and it can operate continuously over long periods.
The blower has high volumetric utilization and high volumetric efficiency, with a compact structure and flexible installation methods.
The full range of models can meet the needs of different users and applications.
Operating Conditions
1. The temperature of the steam entering the transport medium should generally not exceed 40°C.
2. The particle content in the medium must not exceed 100 mg/m³, and the maximum particle size must not exceed half of the minimum working gap.
3. During operation, the bearing temperature must not exceed 95°C, and the lubricating oil temperature must not exceed 65°C.
4. The operating pressure must not exceed the pressure increase range specified on the nameplate.
5. The clearance between the Roots blower impeller and the casing, the impeller and the side plates, and between the impellers has been adjusted at the factory; ensure this clearance is maintained during reassembly.
6. When the Roots blower is running, the oil levels in the main and auxiliary oil tanks should be between the two red lines of the oil level gauge.
7. Check whether any parts of the inlet and outlet connections have been forgotten to be tightened, and whether the pipe supports are complete. For blowers and vacuum pumps that require cooling water, check whether the cooling water installation meets the requirements.
