Roof fans of smoke removal of VKRN DU

All families of fans of smoke removal with radial driving wheels successfully passed certified tests for fire resistance 2 hours at 400 °C and 600 °C, and axial fans - 2 hours at 400 °C and 1 hour at 600 °C.

Characteristics of fans are defined according to an absorption chamber at a free exit from the fan. Characteristics represent curve changes of total or static pressure of the fan depending on an air consumption. Dynamic pressure corresponds to cross section on a flange at the fan exit. All characteristics of fans correspond to the normal atmospheric pressure and the air temperature of 20 °C, density of air of 1,2 kg/m3. For recalculation of characteristics of the fan it is necessary to increase pressure upon coefficient of K=293 / (273+T) where T - value of temperature of the deleted smoke in °C by temperature of the deleted smoke determined in smoke removal calculation. It must be kept in mind that the power consumed by the fan also changes in To time.

The fans which are not intended for use in the mode of all-exchange ventilation - at the VKRN, VKRN-F, VO-21 models - 210 and VO-21 - 210K separate standard sizes noted in the section of the description of these models), during commissioning, acceptance and periodic tests have the allowed duration of continuous work no more than 30 minutes. It is caused by the fact that at a temperature of the moved environment, the corresponding usual air temperature in the serving room, electric motors of the specified fans are overloaded: at VKRN and VKRN-F to 30%, at VO-21-2Yu and VO-21-2YuK to 20%. The specified overload should be considered at selection of the starting and protective equipment of the electric motor. During the operation of the fan in the regular mode when moving the air-gas mix which is formed at the fire, the overload of the electric motor is absent.