Green Museum: Glass Furnace Recuperators

The Corning Museum of Glass is committed to being a responsible steward–leaving not only our collection, but also our facilities and grounds, in the best, most sustainable, state possible for future generations to enjoy. We strive to incorporate green practices in our operations and we consistently look for ways to minimize the environmental footprint of our facilities and our activities.

Part of the Museum’s efforts to become more energy efficient is focused on glassmaking spaces.  The centerpiece of any hot glass shop is the glass melting furnace. These furnaces are not very energy efficient. To offset some energy use, we recuperate heat from the furnace, which incorporates the use of waste heat and reduces energy consumption.

The stack of bricks is the flue, a channel in a chimney for carrying flame and smoke to the outer air. Typically, the flue gasses are cooled by mixing with room air and then vented to the outside. In this method, the heat is entirely wasted.

Air is 78% nitrogen, 21% oxygen and 1% other gasses. That means that 79% of the air does nothing but enter the furnace at room temperature and leave at 2000 degrees F. The furnace expends energy to heat these gasses up with little to show for it. It is a bit like a person blowing on soup to cool it off.

Lewis Olson, the Museum’s Hot Glass Show technical team leader, showed me one device the Museum uses which improves efficiency by about 15%.

Above is one of the Museum’s newer glass melting furnaces. Across the top is a recuperator. It is a device which looks like an automotive muffler. Cool combustion air enters from below behind the furnace. The combustion air travels through a pipe in the center of the recuperator. This pipe is jacketed by a larger pipe through which the exhaust gasses from the furnace travel. The flue gasses exit the furnace through a pipe on the top right of the furnace and exit the recuperator on the top left. The combustion air is mixed with fuel (either natural gas or propane) at the burner which is the green device on the right side of the furnace. The flue gas leaves the furnace around 2000 degrees F. The combustion air is heated from ambient temperature to about 550 degrees F using this waste heat. This reduces the amount the air has to be heated and decreases overall gas consumption.

As part of the Museum’s green initiatives, recuperators are being added to all new and rebuilt furnaces. Learn more about the Museum’s green initiatives: http://www.cmog.org/about/green