Disadvantages of recovering condensate using centrifugal or electrical pumps

Loss of energy

There is a significant loss of energy through this system as
– Flash steam which contains about 50% of the energy present in condensate is vented
– Loss of heat (due to standing losses and radiation losses) results in a drop in condensate temperature
– Overflow losses are prevalent

High downtimes

A combination of high temperature and flashing poses challenges for centrifugal pumps to handle condensate. Cavitation and vapour locking result in frequent pump downtimes
– Centrifugal pumps operate at high rpm, and experience high wear and tear, necessitating frequent maintenance

High operating and capital costs

As the system requires multiple intermediate collection tanks and centrifugal pumps (including a standby centrifugal pump), the capital costs are high
– Additionally, as the system is both power intensive (for pumping) and inefficient in terms of heat recovery, the operating costs are also higher.

Unsafe

Flash steam which is vented out, condensate overflowing from the collection tank, pose a safety hazard as they can cause scalding in case of
accidental contact
– The heat and humidity in the surrounding environment due to flash steam venting, leads to corrosion of pipelines, accessories and equipment in the vicinity and makes the working conditions uncomfortable