Depth Analysis of Mine Counter-rotating Fan

The China Mine Counter-rotating Fan is a kind of axial flow fan. Compared with the traditional axial flow fan, it has the advantages of high efficiency, high wind pressure, large air volume, good performance, wide high-efficiency area, low noise, multiple operation modes, and convenient installation and maintenance.

The counter-rotating ventilator for mine is composed of a collector, a primary ventilator, a secondary ventilator, a diffuser cylinder and a diffuser tower. The fan adopts a counter-rotating structure, the first and second impellers are installed opposite to each other, and the rotation direction is opposite; the fan blades adopt memory twisted blades, and the pages are also opposite to each other, eliminating the need for the middle and rear guide vanes of the general axial flow fan. Reduced pressure loss and improved fan efficiency. Each impeller adopts a cantilever structure and is installed on a flameproof motor to form two independent fans. There is neither traditional long-shaft transmission nor coupling. The structure is simple and the efficiency can be improved.

The explosion-proof motor is installed in the airtight cover in the main air duct. The airtight cover has a certain pressure resistance, which can isolate the motor from the gas containing gas in the flow channel of the fan, and at the same time play a certain role in heat dissipation. The airtight cover has three ducts, which not only play a supporting role, but also communicate the main air duct with the atmosphere, so that fresh air can flow into the airtight cover, and the air in the cover can maintain a positive pressure state, so that the motor is moderately under the condition that the gas concentration is less than 1%. Work, in line with safety explosion-proof requirements.

There is a steady flow ring in the main air duct, so that there is no hump area in the performance curve of the fan, no surge, and it can run stably under any resistance conditions. The noise of the ventilator is low, and the noise of most models can be lower than 90dB (A) without a muffler. Fan impeller blade installation angle can be adjusted, generally divided into five angles of 45°, 40°, 35°, 30° and 25°. The installation angles of the first, second and impeller blades can be the same or different, and can be adjusted to run at any angle within the range of less than or equal to 45°. It can be operated in single stage or double stage, so the adjustable range is very wide, especially in the initial stage of mine production, only one stage can be operated.

Both the ventilator and the diffuser are mounted on a wheeled flatbed cart with tracks underneath, which is very convenient for installation and maintenance. Can be reversed against the wind. In all cases, the anti-wind rate is above 70%; the motor bearing and the motor stator have temperature measuring devices, which can be remotely measured and alarmed. The motor bearings are also equipped with non-stop oil filling and oil discharge pipe devices.