EP 0342484 A2 19891123 - Very noiseless motor driven centrifugal fan.
Title (en)
Very noiseless motor driven centrifugal fan.
Title (de)
Sehr geräuschsarmer, motorangetriebener Fliehkraftlüfter.
Title (fr)
Ventilateur centrifuge très silencieux entraîné par un moteur.
Publication
Application
Priority
IT 2059588 A 19880516
Abstract (en)
The motor driven centrifugal fan (10) according to the present invention has the inner surface (18) of the volute (12) and possibly also the inner surfaces of the sidewalls (13) laterally defining the volute which are roughened. The roughness can comprise projections or recesses of irregular shape, for example of orange-peel type, or of regular shape, for example regular polygons or circles which can be arranged along parallel lines which are or not offset from each other.
IPC 1-7
IPC 8 full level
F04D 29/66 (2006.01)
CPC (source: EP)
F04D 29/667 (2013.01)
Designated contracting state (EPC)
BE DE ES FR
DOCDB simple family (publication)
EP 0342484 A2 19891123; EP 0342484 A3 19901003; IT 1217607 B 19900330; IT 8820595 A0 19880516
DOCDB simple family (application)
EP 89108330 A 19890509; IT 2059588 A 19880516