Correct Steam Traps & Pressure Power Pumps Keeps the OR AHU Running at Royal Columbian Hospital.
The Royal Columbian Hospital is the oldest hospital in the Canadian province of British Columbia and one of the busiest in the Fraser Health Authority. Royal Columbian Hospital is a major tertiary care facility known for trauma care, neurosurgery, and open-heart surgery.
The operating rooms require 100% make up air and a project to upgrade the air system with a new energy efficient one was undertaken with a new rooftop AHU installed. Problems arose on the shoulder seasons with the freeze stats shutting down the air handler under certain outside air conditions. A call was made to Andrew Reynolds to investigate and provide a solution. Upon investigation two major issues were discovered. The steam coil selection was correctly chosen to be freeze proof tube with a tube design, however the 1 ¼” tubes as per the performance data were actually constructed as 5/8” tubes. Secondly, the condensate would backup in the tubes due to lack of vacuum breakers, undersized steam traps and back pressure on the condensate system.
The solution was to replace the freeze proof tube with the correct size, install vacuum breakers, correctly size the steam traps and have a steam powered condensate pump return condensate back to the boiler room.
The results are the AHU now runs under all load conditions and the freeze stats not locking out the system. Chris Nicol from Fraser Health reports the system is performing consistently and reliably.
Did You Know?
Deaerators in Industrial Steam Systems
Deaerators are mechanical devices that remove dissolved gases from boiler feedwater. Deaeration protects the steam system from the effects of corrosive gases. A dissolved oxygen level of 5 parts per billion (ppb) or lower is needed to prevent corrosion in most high-pressure (>200 psi) boilers. While oxygen concentrations of up to 43 ppb may be tolerated in low-pressure boilers, equipment life is extended at little or no cost by limiting the oxygen concentration to 5 ppb. Dissolved carbon dioxide is essentially completely removed by the deaerator.