Blower Installation

Side channel blower (regenerative blower) installation

For electrical installation, ensure that a qualified electrician does the wiring connections and electrical box, as this requires a full knowledge of single phase, 3-phase and motor connections. Air plumbing may need a qualified plumber for some applications.


Blower installation – general procedure

In relation to this video, many water aeration applications do not use a pressure release valves or gauge as illustrated. This is however the professional and perfect way to install a blower. The blower is cooled by its own airflow, so the volume of air released must be within the range of the blower pressure versus air flow curve. Always try and select a blower that fits in the middle half of the curve in terms of air flow and pressure.

The air intake filter prevents large items like stones, insects or lizards getting sucked in and damaging the impeller. Once the fan impeller is damaged (e.g.broken vane), the unit becomes unbalanced.

If in a highly dusty environment, then a different filter to the standard MF air intake filter is needed. A filter more like a generator or tractor filter needs to be installed. For example in a coal mine, coal tar type grease can collect around the impeller. If the impeller is good, a fine particle filter is not used.

Blowers running hot and setting the pressure release valve

Note that pumps and blowers need to be handled differently when it comes to flow control.
This approach is ok for pumps, but not for blowers. One blower customer said: “At the moment we throttle the air blowers until the air relief value starts whistling. And then give the outlet valve two turns to open the air.” This approach is incorrect for an air blower.
The regenerative side channel blower needs to release as much air as possible, as it is cooled by its airflow.
With an air blower, you get it running in the system and aerating as required. The air flow should be such that the impeller housing under the cover is hot, but not so hot that you cannot keep your hand easily on the housing. If the impeller housing is very hot, the blower life will be reduced. If the blower is very hot, the air flow is being restricted, either by the pipe diameter and distance for air delivery or by the air diffuser design (or blocked air diffusers or blocked intake filter), or in this case by the outlet valve setting throttling the air flow. The blower needs to release the amount of air it is designed for. Throttling it can cause it to exceed the design parameters, overheat and burn out.
Once the blower is running as you want it – delivering enough air and not overheating – you then calibrate the pressure release valve. This is done by loosening the screw until it releases air at the operating setup. Air is released at the operating system setup and then you tighten the screw again until air is not released for your blower installation. Then if the blower operating system as setup is exceeded in terms of pressure, the pressure release valve will open and protect the blower.

Instead of non-return valves and large bends as in this video, place the blower above the water level. This is to prevent back siphoning of water into the blower when there is a power failure or the blower is switched off. Water flowing into the blower can damage the blower. Non-return valves can fail and leak, so are not the safest solution.

The blower’s delivery line pip diameter selected depends on the size of the blower, the distance to the point of use and is of a diameter to minimise friction losses in the pipe line.

With three-phase blowers the motor can run backwards if the phases are incorrectly wired. Switch the two outside phases to reverse the blower motor run direction. As stated, a qualified electrician should do the installation for the blower warranty to remain valid.