Regen (regenerative or side-channel) blowers have been successfully employed for SideCar™ air
supply for two decades for the following advantages and characteristics:
- Quiet operation precluding noise problems
- Reasonably efficient in the air flows and pressure range required for SideCar™: up to (5) or (6)
25’ L RBCs per blower @ 2.5 – 3.0 PSIG discharge pressure
- Wide range of airflow increments
- Availability – prompt delivery
- Compact size; small footprint – convenient installation
- Substantial installation savings with standard TEFC motors and weatherproof inlet filter-silencer compatible with unprotected outside installation with proximity to SideCars saving expensive building space and runs of piping
A review of Regen blower operation will assist with the care of these uncomplicated machines. These motor driven blowers are integral air-cooled units; the blower housing is bolted to the motor frame and the impeller is mounted on the motor shaft that is supported by the motor bearings. Cooling relies on ambient air circulation by the fan in the motor, fins on the blower housing and, very importantly, air that is impelled through the blower. Laws of gasses show the temperature of compressed gas increase with pressure and blower characteristics are such that motor HP increases with lower flow, higher discharge pressure conditions. The few Regen blower failures over the 20 year experiences can be traced to the motor bearing overheating problems related to one or more of the preventable conditions described above.
From the above, it can be concluded that the life of a blower is impacted by operating temperature
thus minimizing temperature rise by the following will maximize service life:
- SideCar™ systems are designed so blower air flow and pressure are controlled by system pressure so no throttling with valves is anticipated or necessary. Assuming the air supply piping is reasonably sized, pressure at blower discharge is typically <3.0 PSIG, just a few tenths above that at the SC inlet.
- Religiously monitor the inlet filter and the dirty filter indicator, particularly during those seasons when the air is filled with dandelion, cottonwood seeds, etc. Blinded inlet filter restricts air flow and increases pressure differential across the lower raising temperature and by restricting air flow, depresses process efficiency.
- Perhaps the biggest concern is the heat-trapping effect of the FRP blower enclosures. Tight confinement of blowers is a far greater potential hazard than exposure to the elements.
Preferences for blower shelters are as follows:
- Open side canopy for shade from direct summer sun and comfort of operators if attention is required in foul weather.
- Open; no enclosure required. Regen blowers have been operating for years in cold and snowy northern New York State. The warm draft from the motor fan blows snow away from the blowers. (Be sure the PRV is fitted with an elbow to prevent the entrance of rain that can freeze.)
- If installed in a building, it is imperative the room is well ventilated and unheated. Even with high efficiency motors, the inefficiency and adiabatic heat from the blowers produce high BTUs.
- If Regens are furnished with individual FRP enclosures, it is strongly suggested that the housings be removed (hence latched rather than hinged) and be set aside when the blower is in service. While the housings are fitted with generous louver areas, over time insect screens can become blinded by airborne particulates (see air filter above.) Only if a blower is off line should the housing be installed for protection from the elements.
- Frequently, every day or so, listen for any changes in the sound of the blowers (easier when the housings are removed.) Typically, motor bearings change pitch or sound before failing completely causing catastrophic damage to components.
- The FPZ Regen blowers furnished by Mooers Products are routinely equipped with a protective Thermector switch in the motor windings which is set to open on high temperature, requiring manual reset, that is wired through the magnetic starter. Be sure this switch has been incorporated into the installation wiring of the Regen blowers to protect against failures from overheating from situations discussed above.
- With optimum system design and proper maintenance, Regen blowers will provide years of quiet, efficient service.