Saint-Gobain Corporation: Reduction of Gypsum Board Dryer-Fan Speed Yields Energy Savings and Improved Process Control

Overview

Saint-Gobain’s corporate sustainability program has set aggressive goals on improving energy and water efficiency, as well as in waste and Greenhouse Gas reductions. The sustainability program is organized into pillars around each of these major focus areas.In parallel, the Gypsum business applies World Class Manufacturing (WCM) techniques to identify, prioritize, and implement projects in the environmental, technical reliability, safety, focused improvement, and people development fields. When Saint-Gobain combines these goals with those of their Energy Pillar, they are able to get a sense of how they might improve their process. The partner stacks opportunities up against the performance of all major consumers of gas and electricity to compare them against theoretical minimums and worldwide best practices within the company. From there they can identify how they specifically improve certain processes. The project in Moundsville, West Virginia, was initiated when one of these comparisons showed more than $500,000 of excess electricity being spent on the gypsum board dryer process. Saint-Gobain knew there was a significant cost-savings to be achieved through improving the process.

How They Did It

Since this Saint-Gobain facility is relatively new (less than10 years old) it was thought that there was little room for improvement. However, as is practice, the team reached out anyway to see what opportunities might exist given how much the sustainability space has evolved in the last decade. After a brief audit of what might be studied, the team saw a potential opportunity to assess the five fans serving the gypsum board dryers. These fans were already equipped with Variable Frequency Drives (VFD) to modulate the speed of the fan motors in response to differing demand conditions so if adjustments needed to be made, the team believed they could be executed quickly.

The facility was given a budget of $10,000 and 12 months to complete the work. They started by installing five thermocouples (one for each of the five fan zones) to check for drastic changes in process conditions. They purchased the thermocouples for $5,000 and five new temperature transmitters for $1,500. All installation and wiring were done in house at no additional cost and was completed by March. The working hypothesis for the test was that significant energy savings could be achieved by lowering the fan speeds without impacting the quality of the ultimate product.

Solution

Once the equipment was installed, the team needed to show all of the operators how testing different fan speeds would affect the running of the equipment. Many had been operating it the same way since the plant was commissioned. To achieve these, the team held individual trainings with each operator showing them that the board quality would remain constant with no changes to operational procedure if the fans were adjusted by using specific techniques that would still allow for the test outcomes.

By the end of April, the facility had completed two trials with each operator (eight trials in total) showing that no adverse effect was present on any of their products.

At the beginning of the project, the team put the goal at 2% reduction in electrical consumption in the dryer, but by the end of the testing, they were able to exceed this. The ultimate total reduction was 3%.

With this now known, the fan speeds were reduced by up to 30% with no effect on product quality. The total electrical savings was $68,000 per year.

Expanding Company-Wide

Once this project was completed, the results were shared to the North American Gypsum Energy Champions, a group that works to replicate best practices for sustainability across the gypsum business, and then they were shared with all of Saint-Gobain’s North America Sustainability Champions which sees what can be done company-wide.

Saint-Gobain hopes this process be a model for replication on a general scale. Even if other business units don’t have gypsum board dryers, ensuring that teams look at all processes in a plant – regardless of that plant’s age or what people may guess is efficient – is a discipline that can be adopted across all of their locations.

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