DMAIC Team Takes Aim at Improving Sugar Color, Boosting Production

When honey-toned, raw sugar arrives at Imperial Sugar’s Port Wentworth refinery, it’s already 97 percent pure. Transforming it into pure, snow-white sugar requires taking out that last 3 percent of impurities with a process that is essentially the same as it was nearly 100 years.

Simon Keighley of Hagen & Co. identifies equipment to be examined or tested.

First the refinery team dissolves the sugar into a syrup that resembles a straw-colored solution, then filters out color impurities by passing the sugar solution through columns holding charcoal, or “char” — time-proven equipment that dates back to the early 1900s.

What the refinery team began to observe, though, was that during high production of sugar, the color analysis reported by the lab of the concentrated sugar syrup flowing out of the char was degrading.

“We could predict that by a certain date that we wouldn’t be able to produce white sugar to meet finished product specifications at the 6,200,000 pounds-per-day rate,” says Refinery Manager Jim Flynn. “Color is one of the reasons our production is constrained.”

Getting to the root of the issue meant reexamining their decades-old process for making sugar.

That’s why Imperial Sugar contracted Hagen & Co., a consulting firm that has fine-tuned a problem-solving technique to help teams improve performance.

“The process we’re going through now requires rigorous analysis to get to the root of our color problem. And — as we’re learning in this process — the root of a problem often is not what you think it is initially,” says Flynn.

Hagen & Co.’s proprietary technique, called “Control Factor Analysis,” falls within the framework of the DMAIC (Define, Measure, Analyze, Improve, Control) process, which hails from Six Sigma. The technique focuses on finding out which part of a process — or which “control factor” — is off kilter, then takes steps to solve the problem.

Eight highly experienced Port Wentworth workers, plucked from different areas of the refinery, have come together to form the DMAIC team. Imperial Sugar’s President and CEO John Sheptor joined the group, not as top executive but rather utilizing his career as an engineer and to deliver resources needed to speed the process. A number of corrective actions have been implemented as a result of his ideas.

Their goal: To make sugar that is consistently purer than anything else on the market, while bringing cost-saving efficiencies and streamlined systems.

Every morning for the past four weeks, this DMAIC team has huddled at 6:30 a.m. in a room deep inside the sugar refinery. The walls are plastered with large Post-It sheets listing next action steps and processes that need addressing. Simon Keighley of Hagen & Co. stands before the group, facilitating. The group runs through the previous day’s action steps, then identifies what needs to be examined or tested next.

The team has spent the past four weeks working through 200 different actions to pinpoint char-house issues and improve production. While it is not unusual for a sugar refinery to strive for constant purity, Imperial Sugar’s approach is to examine and profoundly improve a decades-old process.

“We started by inspecting the symptoms more closely than anyone had inspected them before,” explains Keighley. “We looked at the facts of the situation. We didn’t make any assumptions.”

After the first two weeks, the group had identified the top 10 factors affecting char-house production, ranging from poorly functioning equipment to the texture of the char itself.

“One thing we discovered, for example, was that the char wasn’t the same as it used to be, and we wondered why,” says Flynn. When char is fresh, it looks like course pepper. Over time, it breaks down into fine particles, which should be screened out by existing equipment. But the screens weren’t working properly.

With too many fine particles in the mix, it took longer for the sugar solution to flow through. (Imagine trying to flow liquid through course grain versus fine powder.) Output bottlenecked. “So you could try to decrease the sugar content of the solution, and increase your flow rate, but then it takes longer to boil down later in the process,” explains Keighley. Workers could try to do more sugar washing to get color out, but that meant some of the sugar would be lost and water wasted.

“The rate-limiting factor, then, were these particles,” says Keighley. “Removing the fine particles was critical to improving color and sugar content.”

The solution came in the form of equipment repair, as well as some process improvements. “What I thought was cool about this was that some of our team members came up with very creative solutions,” says Flynn.

One technician, Dean Jordan, devised an ingenious way to increase the rate at which certain char-house equipment was removed for cleaning then returned — allowing for increased production rates.

As a result, says Flynn, “We are seeing much better colors. That means, instead of slowing down to produce better color, we can maintain higher production rates and send more material to packaging.”

Both Keighley and Flynn see this process as the beginning of a culture shift. “We need dozens of teams like this in place, working on continuous improvements,” says Flynn. “Simon is working with us to develop ways of sustaining the structure we’ve started.”

“What we hope will come out of this is that we can move on and look at other stations in the plant and say, What problems do we see? And how can we stop them?” says Keighley. “We’ll use this as a stepping stone to assist with a training program throughout the plant.”

Members of the Port Wentworth DMAIC team are:
George Sexton, Operator, White Sugar Pan Boiler
Dean Jordan, Instrument Electrical Technician
Gerrad Kerby, Maintenance Mechanic
Ricky Kessler, Low-Grade Boiler Operator
Kerry Maennache, Affination Operator
John Burke, Shift Superintendent
Robert Wilkerson, White Sugar Melter Man
Michel Whitaker, Reliability Engineer