Ventilation Fan Reducing Air Pollution in Tunnels
TFA series tunnel axial fans are dedicated ventilation fans for tunnel construction, which are suitable for tunnel construction ventilation of various roads, railways and hydropower projects and construction ventilation of other underground projects. The fan motor is installed in the casing, and the impeller and the motor are directly connected. The inlet and outlet of the fan can be equipped with a silencer to greatly reduce the ventilation noise. The blade angle of the ventilator can be fixed or adjustable. Among them, the "variable multi-speed" special ventilator is more suitable for long-distance tunnel construction, and the energy-saving effect is more obvious.
The motor of this series of fans is installed in the casing, and the impeller and the motor are directly connected to reduce the bearing loss; the fan is equipped with air inlet and outlet silencers, which can greatly reduce the noise of the fan. The blade materials are made of high-quality carbon steel, alloy aluminum, stainless steel and other materials for users to choose in different environments; the fan is designed with single speed A and B type, multi-speed C type and two-speed D type, TFA (3B) three-stage afterburner Frequency conversion energy-saving type, TFA (4B four-stage afterburner frequency conversion energy-saving type, E-type four-stage double counter-rotating multi-speed type, etc. are available for users to choose.
Scope of Application
TFA series of ventilators can be suitable for the ventilation needs in the plateau environment, the ambient air temperature is -15℃~+40℃; the relative humidity of the ambient air does not exceed 90% at +25℃; there is no strong vibration and corrosive gas, etc.; it can be installed In the air intake tunnels and mines, it is matched with the positive pressure air duct and used for press-in ventilation.
- The outer cylinder and structural parts of the ventilator are welded by carbon steel plates, the inner cylinder is welded by perforated plates, and noise-absorbing materials are filled between the inner and outer cylinders.
- The fan motor should be properly grounded, and there is a grounding device at the bottom of the fan. The motor changes its speed by changing its poles. There are multiple speed changes such as two-speed and three-speed. Its stator winding is a single set of windings at two speeds, and a double set of windings at three speeds. The stator windings of the motor are connected at various speed ratios. The method and the number of outlet terminals meet the requirements of the factory nameplate.
- Wiring of the ventilator shall be in accordance with the marking on the wiring position of the junction box wiring board specified on the nameplate, and wiring shall be carried out according to the wiring instructions.
- The ventilator adopts the direct connection method of impeller and motor, which has the characteristics of compact structure, sturdiness and durability, safe use and convenient maintenance.
- One fan can be used for multiple purposes. In the process of tunneling, according to different ventilation requirements, the first-level fan and the second-level fan can be used separately, but it is recommended that the two-level operation at the same time has the best energy-saving effect.
- There is a grounding device welded on the support leg of the fan, and the grounding is reliable to ensure the safety of use.
- The air outlet of the diffuser muffler can be directly connected to the colloidal air duct, eliminating the need for variable diameter short joints.
- The working principle of the fan is that the two-stage impellers rotate in opposite directions, that is, the first-stage impeller rotates clockwise, and the second-stage impeller rotates counterclockwise. The number of blades of the two impellers is prime to each other, and the thickness is equal. For the twisted arc plate shape, the twist angle and the installation angle of the blade of the first stage impeller are larger than the twist angle and the installation angle of the second stage impeller blade. When the air flows into the first-stage impeller to obtain energy and is discharged through the second-stage impeller, the second-stage impeller also has the function of the rear guide vane in the ordinary axial flow fan, which rectifies the airflow after the first-stage impeller does work, and increases the airflow. This energy reduces the wake vortex, so as to achieve high efficiency and high wind pressure that ordinary axial flow fans cannot achieve.
- Ventilators are generally designed to be installed horizontally, and the safe operation time before the first overhaul should be no less than 13000h.