APPLICATION
High resistance to corrosion resulting from the use of high-quality plastic materials makes the radial fans of type VRE
suitable in particular for process exhausting devices in the chemical and pharmaceutical industries, for ventilating
laboratories, battery rooms, pickling and washing plants, galvanic and agricultural facilities etc.
TECHNICAL DESCRIPTION
Main components of the fans are the impeller, spiral casing, casing connections, base, and driving motor. The motor is
flange-connected directly to the base and completely separated from the flowing medium. The impeller has been arranged
on the motor shaft and is driven directly. Steel components - such as screws, hub and hub connections - are made of acid-
resistant steel or protected against corrosion by plastic coverings.
The aerodynamic design of the fans is state-of-the-art so that high efficiency, low sound levels, and high performance
density can be achieved.
Every fan is supplied as a complete assembly unit ready for use. Vibration absorbers matched in size and quantity, elastic
connections on the pressure and suction sides, and a condensate drain bore with closing cap are elements of the standard
range of delivery.
Design features
Impeller:
There are two impeller designs covering a wide range of performance:
Type 731 with vanes curved backward
Type 734 with vanes curved forward
Special impellers are used for special applications. Impellers with vanes in radial arrangement, for instance,
are advantageous if the medium conveyed contains intensely sticking substances.
The impellers are made of single components and assembled with progressive joining methods. Dynamic
balancing complies with ISO 1940.
Materials: PVC, PPs, PVDF, FRP (for high demands), electrically conductive plastic material (explosion-proof fans)
Casing:
The casings are made of deep-drawn half shells (sizes 100 … 250 made of PVC or PPs) or even side walls
and a jacket which are tightly welded. The connection diameter on the suction side is in any case identical with
the nominal size of the fan. The casing can be opened on the suction side for cleaning. A condensate drain has
been arranged in deepest position.
Sealness of the shaft lead-through that is sufficient for many applications results from the vanes with far end
arrangement. Higher demands on sealness are met by an additional seal between impeller and casing (see
section Shaft seal).
A shatter guard or an additional FRP reinforcement should be arranged for cases of high demands on safety.
A wide range of casing connections is available for connecting ventilation lines.
Note: Connected plant components must not load the fan mechanically.
Materials: PVC, PPs, PVDF, FRP (for high demands), electrically conductive plastic material (explosion-proof fans)
Base:
Robust welded design of zinc-coated sheet steel, optionally available: varnished or of stainless steel.
Motors:
Standard motor: 3 ~ 400 V/ 50 Hz, degree of protection IP 54, design B 5 (in special cases B 14 or B 3)
Single-phase motors 230 V/ 50 Hz, motors with special voltages and different degree of protection, pole-
changing and explosion-proof motors
Motors with thermal winding protection (PTC resistor) --> special design
TS
Motors with integrated frequency inverter --> special design
MFU
03
MIETZSCH GmbH Lufttechnik Dresden
Großenhainer Str. 137
01129 Dresden
Fax (0351) 8 58 00 74
http://www.mietzsch.de
intake socket
elastic connection
with tensioning tape
impeller
hub protection cap
impeller fastening
casing
base
motor fastening
adapter ring
motor
vibration absorbers
condensate drain
Radial fans of plastic materials
Series VRE
direct driven
Technical explanation
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