Steam traps are energy wasters, especially within a tire-manufacturing plant. “It takes a lot of steam and control to get the process right,” said David Gustafson, global wireless applications business development manager, Emerson Automation Solutions. He shared the story of a North American factory that saved more than $60,000 of steam/energy and reduced carbon emissions by an estimated 225 tons in the first year of implementing Connected Services during his presentation at the 2017 Emerson Global Users Exchange in Minneapolis.
“The facility was very old compared to its peers,” said Gustafson. “Soft market conditions and competitive corporate culture threatened facility closure. They were looking for a way to adopt technology so they could perform as a top-quartile facility, but they didn’t have that much money to spend.”
The plant produces approximately 15,000 race-car tires annually. “They were spending a lot of money on the electricity side,” said Gustafson. “Steam is a big, big spend. Where might there be some steam leaks in the system? First, they looked at flange leaks in the pipe system. Then they looked at insulation. And finally they looked at steam traps. Larger orifices with higher pressure were easy to identify.”
At the beginning of the project, the plant added 160 steam trap monitors, many of them in hot or uncomfortable places, such as underneath tire presses. “If you could leave something there to monitor it instead, that would be a better way to go,” explained Gustafson. The number expanded to 192 after the first year, due primarily to the financial success of the monitoring and reporting that Emerson was able to provide.
What can go wrong?
Plugging and blow-through are the two biggest culprits in steam-trap failure. “Condensation can back up and interrupt the vulcanization process,” explained Gustafson. “And you can have a water hammer where the condensation can affect downstream equipment.”
The critical traps were being checked every six months by two union employees who would walk around and collect the data manually. It took them two weeks; many of the noncritical traps were never tested; and there was no tracking of whether repairs were made.
Losing these “jobs” made the union resistant at first to replacing the manual data collection with an automated solution; plus, finding a suitable solution was proving tricky. “Traps will typically last between three and seven years,” explained Gustafson. “The capital budget for an automated monitoring upgrade was little to none. On-site steam-trap expertise was minimal. They used steam intermittently for some processes. The IT department was causing unnecessary complexity and cost. A wired solution wasn’t economically feasible.”
Problem solvers
The best solution would include actionable data transfer. “We had control information that needed to be conveyed to the IT environment,” said Gustafson. Emerson Connected Services became the communications choice, but first each trap was equipped with a Rosemount 708 wireless acoustic transmitter with steam trap monitor. The transmitter uses a piezoelectric element to listen for leak events.
With the sensor technology onsite, Emerson’s 1410 DIN-rail-mount wireless gateway was added, and cellular connectivity was used to punch the data out to subject matter experts at Emerson’s Center of Excellence in Singapore, who can make suggestions and collaborate with the onsite team.
The Connected Services contract is a five-year subscription, with Emerson responsible for delivering actionable data, as well as installing and maintaining the infrastructure. The cost is about $35/trap/month on a five-year agreement. The tire manufacturer is responsible for the steam-trap remediation.
Extra, extra, read all about it
“We provide two reports at this plant,” explained Gustafson, “one for maintenance and one for the operations executive team.” A weekly maintenance report includes short and sweet actions for failure mode, location, pressure, trap type and recommended remediation. The monthly executive report identifies the business impact on energy, emissions savings and losses, projections, peer comparisons and performance trends.
“Reports can be generated daily with the Connected Services communication, but the company didn’t want daily,” said Gustafson. Total identified opportunity savings exceeding service cost resulted in an estimated $20,000 positive cash flow. Within the first year, actual results indicated no more concerns with water hammer or suboptimal process performance, and no process interruptions, in addition to $60,000 steam/energy savings and the 225-ton carbon-emissions reduction.
The steam-trap monitoring service contract required no upfront investment, and the service paid for itself with positive cash flow. Because of the access to Emerson’s Singapore Center of Excellence, there was no SME learning curve and no responsibility to manually monitor steam traps any longer.
“Cellular allows us to never touch a service provider because of the direct peer-to-peer, high-speed communication,” explained Gustafson. “The analytics start with an algorithm and then end up in the hands of the SMEs in Singapore, who cleanse the data and compile the reports.”