Given today’s skilled workforce shortage, figuring out how to get the most productivity from the fewest workers has become one of a power sector’s top challenges. How can a plant stay on top of its output requirements when finding and retaining qualified workers is so difficult?
With spare man-hours being a luxury few can afford, two questions are at the top of most plant managers’ minds:
1. How can we avoid downtime?
2. Are we maximizing our workers’ time and capability?
Following are stories of two facilities that found the expertise they needed to address those issues with innovative, “outside-the-box” solutions.
Keeping downtime at bay
Downtime has always been a costly and inconvenient burden, and finding the resources to make up for time lost to equipment failure can be nearly impossible. A well-known North American tissue manufacturer found itself with old boiler equipment that was not up to the job and needed to be replaced—but they had to find a solution that wouldn’t cause downtime, which they simply could not afford.
Their old equipment did not reach full heating capacity as required. The boiler was rated for a certain steam output, but the burner couldn’t provide enough heat to make that steam. They had a second boiler, but switching required a start-and-stop process that added up to higher operating costs. Every stop meant purging the boiler with air and adding additional wear-and-tear on the system. The process also meant lost energy and additional man-hours. It was not a sustainable solution.
They needed a more reliable source of heat, along with ability to meet NOx emission requirements with better fuel efficiency and a safer system. If they didn’t get the NOx emissions into compliance, they risked hefty fines from their home state. So what would work?
A combination of a new burner, new fuel piping train, and a new variable frequency drive (vfd) was proposed to address the heating efficiency problem. This combination saved costs by reusing the existing controls (which had just been put in place a few years earlier). They included Preferred Utilities BurnerMate Universal (BMU) parallel positioning controls, a built-in flame safe guard, and a touch-screen user interface.
The company proposing this solution had been servicing the manufacturer for years, so they had the knowledge to not only source the right equipment but also coordinate the entire project. They provided a highly qualified subcontractor who provided a complete turnkey solution, removing the old boiler and completely replacing it, attaching the new burner and gas lines and wiring the controls. They took just 11 days to install all the equipment and get it fully functional. It met NOx emissions standards and achieved higher efficiency and turn-down. The entire project, from initial analysis to completion, took less than eight weeks.
Working with the right consultants in a case like this is particularly important because they must be experienced with a full range of boiler equipment so they can always utilize the one best suited for the application. Without the right expertise they might recommend ill-suited equipment that will be detrimental to plant staff who will need to deal with the repercussions and possible failure in the future. That’s more risked downtime—something that was simply not an option in this application.
The burner installed in this application burned natural gas, achieved a 10-1 turn-down, and reached 30ppm NOx (the previous level was 50ppm). Additionally, the installation included a 40,000 pounds-per-hour steam boiler and a Cleaver Brooks water tube boiler.
Keeping boilers under control
A mammoth steel processing plant was far behind in a boiler upgrade project. They turned to an outside consultant to help them pinpoint the problems in the application and get the project back on track.
This was the largest project of its kind in the United States at the time. The engineer had to guarantee less than 25.65 PPM NOx and less than 48.60 PPM CO. The project also required 85 dBA noise level at three feet. All of these stringent requirements ended up being met.
An added challenged faced by the consultant concerned the type of controls to be implemented in the application. The management of this facility had traditionally been against Human Machine Interface/Operator Interface Terminals (HMI/OIT) and had not allowed them. Given their experience with these types of controls, the consultant’s challenge was to convince the customer that offering an OIT is an advantage.
In the end, this solution was accepted because the consultant offered a BMU. The LCD screen is standard on the BMU and is a back-up that will provide them with the boiler-burner operation should the OIT fail. To assist in the rollout of these new controls, the consultant also offered a two-day on-site training session.
The consultant matched the proper controls to the boilers and fast-tracked the resulting installation. A four-week submittal, proposed to the consulting engineers, got approval for both boilers and burners to proceed with manufacturing and meet the schedule.
The final application included three X-Plus burners on three B&W 60,000 PPH boilers with BMU controls. The control system and VFD was located on a high ambient temperature environment of 139°F and in corrosive atmosphere. All controls, hardware, and VFD were rated for 122°F. NEMA 4X requirement encloses the heat from the temperature rise and will exceed all temperature rating of the electrical components. In order to meet the reliability requirements, the consultant provided a NEMA 4X enclosure with NEMA 4 rated air conditioning system.
In both these applications, timing was critical. They could not allow the boiler system to fail, but they also could not afford a lengthy downtime for upgrades. Overcoming a pre-conceived mindset and looking for creative solutions allowed the facilities to resolve their problems and stay productive. In the end, an outside perspective gave them access to both the knowledge and technology they needed to conserve workforce time and talent.
About the author: David Bohn is President and CEO at Preferred Utilities Manufacturing Corporation, an engineering-based manufacturer of products for commercial, institutional, industrial and nuclear power facilities.