UPGRADE OF VTS-25M fans

In 2008, the Artyomovsky Machine Building Plant VENTPROM designers carried out upgrading of the VTs-25M main ventilation fans by order of the Zarechnaya mine.

According to the specification, it was required to increase the fan capacity by 20% without changing the fan housing elements.

The fan was upgraded by changing the design of the impeller and inlet elements of the wetted part and using a more powerful motor.

The upgraded fan differs from the basic VTs 25M fan by the following features:
1. All linear dimensions of the impeller are increased by 11%.
2. Inlet cone convergence is reduced by 17%.
3. Inlet cone convergence is reduced by 17%.

The SKF bearings are installed in the new shaft assembly. The SKF Explorer bearings with the same geometric dimensions as the bearings manufactured by the Minsk bearing plant allow 90% more load capacity and 50% higher allowable speed.

The maximum power consumption of the upgraded fan with the guide vanes` blades positioned at the angle of 0º is 700 kW. Providing the necessary margin for power consumption, the asynchronous electric motor with the AOD-800-8U1 squirrel-cage rotor having a capacity of 800 kW.

The upgraded fan's impeller has a very high flywheel effect, which means a heavy start of the main drive. A soft start control system was adopted to eliminate shock loads on the mains and the drive motor.

Two prototypes of the upgraded VTs 25M/28 fans were installed in January 2009 and are in operation at the Zarechnaya mine in the Kemerovo region. The first operating experience showed a high efficiency of ventilation and stable fan operation.