Description of the fans manufactured in the USSR, their classification and specifications given in the appropriate directories and reference books. We note here briefly only some features of interest to planners.
Until recently, enjoyed great popularity centrifugal fans type EVR. Currently: Production ceased. Nevertheless, many of these fans in operation and they should be saying a few words.
Dignity fans EVR - lightness and compactness. Disadvantages - low efficiency and low strength tselnoshtampovannogo wheels These fans have a large number of blades, thus easily become clogged with dust and sticky deposits. Small same stiffness wheels make it extremely difficult to clean. Fans type EVR unsuitable for local exhaust, such as painting or plating plants, especially in the presence of the latter plating chrome baths. These fans are not suitable for removing smoke, such as ventilation, smoke-house furnaces.
Fans of new series of TS4 and TS4-70-76 are characterized by high efficiency. These fans are designed for air handling systems and general exchange ventilation hoods, as well as exhaust systems with local suction in the absence of the exhaust air dust. A relatively small number of blades facilitates cleaning. But to recommend these fans for exhaust from, say, plating baths is not necessary.
So-called "dust" fans are characterized by strong wheel with a small number of blades. Besides its direct purpose - removing air contaminated with particulate matter - these fans can be used to move the media, generating rainfall. Cleaning of rain lasting shestilopastnogo wheel is relatively simple and does not threaten damage the blades, as it can be a fan of other types.
Dust fans are not designed for installation on a single shaft with the motor. This is understandable, since the aspiration systems require a wide range of pressures, ie, a wide range of numbers of revolutions. Use fans for dust exhaust systems that remove sediments which can form a hazard, it is impractical, since such systems and usually prefer to install fans on the same shaft with the motor.
Fans 11,6-46 type characterized by low resistance wheels. This lack of them should be considered when designing.
As is known, axial flow fans are characterized by relatively low pressures at high productivity. These properties is determined by the range of applications in industrial ventilation.
The main goal of axial fans - exhaust systems general ventilation. Large axial fans series Y-12 work sometimes as inlet.
Installation of small axial fans directly in the working environment is unacceptable, as they create significant noise, obscuring the room when you install them in the window openings, spoil the facade of the building and because of the large diameter exhaust pipes make it difficult to release the exhaust air above the roof of the building.
If the axial fans are installed in isolated areas - cameras, there are no contraindications to their use there. Axial fans are quite acceptable if you install them in the exhaust air shafts on the roof, of course, subject to their availability for service. General ventilation of hot and welding workshops, garages, etc., may well be based on the axial fans.
In recent years, the so-called roof fans, intended for installation on the roof of the building. These fans are satisfied with both centrifugal as well n with axial wheels. Impeller rotates in a horizontal plane on vertical shafts. Roof fans are made with immediate landing wheels on the motor shaft and belt drive.