Smoke exhaust fans VR 86-77 DU

VR 86-77 (80-70) DU is a modification of the general industrial radial fan VR 80-75. Radial low-pressure fan, single directional suction VR 86-77 DU is a blade system consisting of: impeller, spiral housing, frame (bedplate), diffuser and asynchronous motor (380V, 50Hz), of different rotation speed and power for expanding the range of aerodynamic characteristics.

The impeller has 13 (No. 2.5-No.8) and 12 (No. 12,5) backward curved blades. The use of radial fans with backward curved blades provides higher efficiency, in contrast to fans with forward curved blades. Fans with backward curved blades also easily tolerate overloads in terms of airflow.

In regards to the direction of the impeller rotation, the fans can be of the right and left rotation. If viewed from the inlet port and the impeller rotates clockwise – the fan is of the right rotation and, conversely, counterclockwise – of the left rotation.

VR 86-77 fan as a spiral turning body, which can be installed in 6 positions (from 0° to 315°, with a range of 45°, 180° – on special order) and attached to a welded frame (bedplate), which during installation can be mounted on vibration isolators. The number and size of vibration isolators depend on the size of the fan.

Designation of VR 86-77 smoke exhaust fans

VR 86-77 smoke exhaust fans are used in the emergency smoke ventilation systems. They can have blast protection. They are intended for removal from a building of smoke-air mixtures caused by fire. Such fans are capable to work constantly with gases up to 400°С, if their temperature reaches 600°С no more than 120 minutes.

Structural versions

VR 86-77 ДУ fans are manufactured in 8 standard sizes (No. 2.5; 3.15, 4; 5; 6.3; 8; 10; 12.5).

In regards to the design, it is possible to manufacture fans according to scheme 1 (the impeller is located on the motor shaft) and scheme 5 (the torque from the electric motor to the impeller is transmitted by the belt drive).

Operation conditions

Centrifugal fans VR 86-77 DU and VR 80-70 DU are used to move non-explosive smoke-air mixtures that do not contain explosives, fibrous and sticky materials, conductive dust, corrosive gases and vapors in concentrations destroying metals and insulation, with a dust content of no more than 10 mg/m³.

The fans are designed for operation in conditions of moderate climate temperate (M) (-40°C to 40°C) and tropical (T) (-10°C to 50°C) climate of the 2^nd and 3^rd location environmental classes in accordance with GOST 15150-69.

For the motor protection from atmospheric influences (precipitation), fans are allowed to operate in a temperate climate of the 1^st location environmental class, in accordance with GOST 15150-69.

When using these fans in case of fire, their further operation is unacceptable.