CoFimCo - Who we are.

	Performance and sound Scaled model fans are tested in two wind tunnels (1250mm./48” and 2000 mm./78” diameters) using the British Standard fan test procedure BS 848. From this data, non-dimensional characteristic fan curves are generated. Two test rigs (actual air coolers), suitable for 4’-6’ and 9’-14’ fan diameter, are then used to verify the above curves and to determine the influence of variables like tip clearance, aerodynamic disturbances, and inlet shape. Sound tests are performed on these test rigs as well, in accordance to the DIN 45635 standard. For the large air cooler, a remote operated vane system on the top of the unit allows automated modulation of the air resistance across a wide range of conditions.
	Principal Test Equipment All test equipments are redundant to allow in house and on site tests at the same time. • electronic portable balancing equipment • vibration analyzer with FFT capability • precision sound level meters • multi-channel strain gauge data acquisition system (telemetry and slip ring) • dedicated computers and software for the above systems • precision micromanometers • digital anemometers • pitot tubes • inverters • torque meters • hardness meters • tachometers • strobe lights • Watt meters • Ampere-meters • ...etc

	Endurance All fan series are fatigue tested. A constant amplitude sinusoidal load is applied to the blade along with a superimposed static load. The stress levels at the most critical sections of the blade and hub are continuously monitored by a strain gauge data acquisition system. The typical S-N curve (alternate stress vs. number of cycles) is generated by testing several blades at different load levels. The experimental determined fatigue limit is then compared to the design calculated stress to insure infinite life of our fans. Blade natural frequency* Blade natural frequency is determined for blades of any configuration in the applicable diameter range. It is first calculated by our custom designed computer program and then is experimentally checked by an impulse test using an accelerometer and a vibration analyzer. The stiffening effect of the centrifugal force is included in our analysis. The Campbell’s diagram is used to identify any critical speeds to insure safe operation of the fan. Material characteristics Material chemical composition and mechanical characteristics are guaranteed by our suppliers who provide a certificate for each lot certifying compliance with the required specification. Cofimco periodically double checks the material properties through independent tests at a University lab. Fan Design Cofimco use advanced tools for dimensioning and verification of complete fans and single components. In this way, based on the real fans geometry, it is possible to simulate the exact entity of the loads acting on the fans; Cofimco can display possible problems during the design phase in order to prevent failure during operation