Malt whisky maker turns to swirl meters for energy control

Dufftown, Scotland - Whisky distiller William Grant has employed swirl meters to identify areas for potential energy savings at its Glenfiddich distillery. The project was part of a plan to improve energy efficiency and to gather data ahead of purchasing a new boiler at the Dufftown plant, which uses steam in its distillation process to heat the fermented liquid to boiling point.

Steam for the whisky distillation process is generated from a central boilerhouse previously using two boilers. Recent investment in a third boiler increased the total steam producing capability of the site by about 25%. The design of the steam distribution system allows steam to move in both directions from the boilers and back from the site if it is not needed.

Measuring the steam required a very accurate, multi-directional steam meter capable of being retrofitted into William Grant’s existing pipe network. ABB instrumentation supplier JWF Process Solutions suggested using ABB swirl meters for the job, partly because they require just three pipe diameters upstream and one pipe diameter downstream, making them suitable for retrofit applications.

ABB's swirl meters provide stand-alone volume flow measurement for a wide variety of substances and direct mass flow of dry or saturated steam, enabling greater accuracy with virtually zero maintenance – especially in applications where the flow varies over a significant range. Rather than an accuracy of two percent of the upper flow range, which is typical for an orifice plate installation, swirl meters offer an accuracy class as good as +/-0.5 percent of reading over their entire flow range.

Measuring mass flow rather than volume, the meters are accurate to within +/-0.5% of reading, with a turndown up to ten times greater than that of an orifice plate, according to ABB. JWF supplied and project managed the complete installation of the meters with the assistance of William Grant’s project team.

With the installation of 11 swirl meters, William Grant is cutting energy consumption at particular departments and processes and usign information from the meters to address problems such as poor lagging or steam leaks leading to steam wastage. The data is also being used to better manage the steam production around the site by highlighting consumption and trends, while the company can also now look at fluctuations within the system to reveal the best way to balance steam requirements around the site.

“Without steam meters you don’t know what’s being used, when or where," said Tony Allen, William Grant’s project engineer. "Previously, the system just ran and you used steam when it was required. Sometimes the steam would run out, delaying the process. ABB’s swirl meters accurately measure steam demand and reveal how much steam is being used by each piece of equipment. By analysing this data we can balance the steam use around the site and optimise our energy usage. The meters are beneficial and have already proved their value in terms of better controlling energy and steam usage around the site.”

According to Allen, the data has already been used to size the replacement boiler. "The increased boiler efficiency and steam-raising capability of the new system have created energy savings and spirit quality has been enhanced by maintaining a constant supply pressure to the stills. We are now looking into enhancement possibilities for future development and the information from the meters is a very good way to justify the improvements needed onsite.”