All new thermal power plants, refineries or expansion projects require some kind of steam blow process to clean the system prior to startup and operation. Steam blows are necessary to protect the turbine or plant equipment from damage upon startup or during operation, which could cost plant owners millions of dollars in repairs and even more in unscheduled down time.
The first steam blows were unbelievably noisy and unsafe, and in most cases even louder than a modern jet engine at full speed. With an open-ended pipe venting high velocity steam straight into the atmosphere, steam blows were known to break glass windows in buildings or nearby offices. As a result of the noise concerns and related safety issues, alternative steam blow methods were sought after and developed. High-pressure, quick-opening steam blow valves were introduced, along with water injection into the temporary steam exit piping to reduce the venting steam velocities. This led to the exhaustive steam blow, or “puff blow”, method for cleaning steam systems—a process that could be performed in a safer manner and with less noise than previous methods. This was a major development in solving part of the equation.
Although the noise issue was conquered, there was still a ways to go in the evolution of the steam blow process. As a result of the high pressures required for exhaustive steam blows, the permanent and temporary systems were subjected to very high vibrations and stresses. In addition to stress concerns, exhaustive steam blowing on larger systems could take several weeks, or even months, to achieve cleanliness levels required by most turbine manufacturers or plant engineers.
It wasn’t until much later that these shortcomings were addressed with the introduction of the low-pressure continuous steam blow process. This process has become the industry standard for steam blowing today, and is widely used on new construction projects around the globe. Steam blows could finally be performed around the clock, with minimal disruption to surrounding work activities. This resulted in a major reduction in the time required to clean the systems to turbine OEM acceptance criteria, and also allowed project managers to more accurately plan for this critical path activity.
B&W Energy Services will continue to seek out new innovations that can help conserve time and the environment, if it can be done safely– like our “Dry Silencer”, which eliminated the need for water injection into the temporary steam blow piping, and our AquaLazing services, which further schedule reduction of steam blows. See our December whitepaper on AquaLazing for information on real world savings. By continuing with improvements that have major impacts on the success of your project, B&W will remain the premier provider of these services for years to come.