Boilers are used extensively in industry to generate power by way of a steam power generator. Boilers can also be used as a heating method for industrial and residential buildings. The electric motors that operate the draft fans and feedwater pumps are typically controlled by a variable frequency drive (VFD), allowing for precise control of the boiler operation.

Industrial boilers use draft fans to either push or pull air into the furnace of the boiler. These fans need constant, uninterrupted power to maintain high efficiency. Sags and outages in the AC line can cause the drive running the draft fans to trip on an undervoltage condition, resulting in shutdown of the fan. Loss of airflow through the boiler can require shutdown resulting in long periods of downtime to restart the boiler. Draft fan drive trips may also cause excessive or catastrophic damage to the boiler. In these cases, the application can benefit from a Bonitron UPD Ride-Thru System.

Draft Fan

Forced Draft Fan

  • Fan pushes combustion air into the burner and through the combustion chamber
  • Fan pushes the flue gases out through the vent
  • Creates positive pressure in the furnace

Induced Draft Fan

  • Fan pulls air in the burner and throug the combustion chamber
  • Fan pushes the flue gases out through the vent
  • Creates negative pressure in the furnace
Air and Gas Flow Chart

Bonitron UPD Ride-Thru Systems protect boiler draft fan drives from undervoltage drive trips by providing seamless power to draft fan drives in the event of sags and outages. Long periods of downtime and possible damage to the boiler caused by loss of power to the drives can be prevented using Bonitron UPD Ride-Thru Systems, resulting in maintained efficiency and extended uptime.

Systems with multiple boilers can also benefit from the use of a shared common DC bus. The use of a common bus allows for the reduction of wiring and components, and the linked drives can shared components, such as a UPD Ride-Thru System.

Feedwater Pumps

Industrial boilers use feedwater pumps to supply the needed water to the boiler to generate steam. It is critical for this pump to have constant, uninterrupted power. If the drive running the feedwater pump loses power and trips on an undervoltage condition, the water level in the boiler will lower. Low water conditions may cause the boiler to overheat, possibly resulting in severe or catastrophic damage. If the boiler is equipped with a low water trip switch, the boiler will shut off in these low water situations and may result in costly downtime. The Bonitron Uninterruptible Power for Drives (UPD) Ride-Thru System prevents these undervoltage drive trips, resulting in more uptime for boiler applications.

Feedwater Pump Progressing Cavity Pump
DC Bus RideThru

UPD Uninterruptible Power for Drives

  • Protect from power sags and outages
  • S3460 and S3534 Series
  • Various sizes and durations available
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