Spectra Energy’s BC Pipeline and BC Field Services businesses are an integral part of B.C.’s natural gas midstream industry, strategically located to connect vast supply with growing demand.
The McMahon plant is the first natural gas facility constructed in BC. It has a processing capacity of 810 MMcf/d with recovery of up to 98% sulfur.
The west amine reboiler for gas train 1 has been selected historically to study the effects of equipment changes in the effort to improve process efficiencies and extend equipment life that is involved in the removal process of sulphur from the raw gas field network. The amine reboiler process is critical to sweeten the gas before transport in the main distribution pipeline. Andrew Reynolds relationship with the plant and his experience and knowledge of steam applications and condensate removal was key to the plant contacting him for advice. The heat exchanger tube bundles were lasting less than a year and the plant manager was looking for solutions to extend the bundles life. Upon investigation, it was apparent the heat exchanger system was running completely flooded. This will not only lead to corrosion and reduced tube bundle life but also decreased production in the reboiler still. The solution was immediately apparent to Andrew. A proposal was made to install a quad condensate removal pump package system. This system will provide effective condensate drainage under all load conditions including vacuum.
It was during start-up and commissioning of the new condensate removal system that the tube bundle level gauge used to monitor the degree of flooding dropped to zero. It was noticed by one of the Spectra Gas train operators who yelled out “What happened to the condensate – is the steam valve open!??” It was, and the condensate did not remain in the tubes anymore. This solution solved the issue of reduced output, extensive bundle corrosion, costly repairs and downtime.
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.