Glass tube heat exchangers allow for the efficient use of energy in malt houses.

Beer ranks among the world’s most popular alcoholic drinks. It all starts with malt made from special grains, usually malting barley. In malt houses, these grains are soaked in water until they germinate. As a result, the water content rises to approximately 40 percent. After five to seven days, germination is put to an end by gentle drying, called kiln-drying. Finally, the germ bud that started to grow is removed, and the malt is ready for storage.

The air inside the drying plants in modern malt houses is heated indirectly to temperatures as high as 212oF (100oC). Natural gas burners produce a hot gas that heats up the air indirectly using a heat exchanger that contains bundles of steel tubes. Indirect heating ensures that the malt remains free from the combustion products of fossil fuels. This firing method also prevents hazardous nitrosamines from forming.

The glass tubes used in the malt house heat exchangers are approximately 13' long and are placed into the frame construction by hand.

Heat recovery from the hot gases prior to exhaust is an important option for some malt houses. In the light of high energy costs, an investment in heat recovery equipment can redeem itself quickly. For the malt drying applications, one choice is a large-format glass tube heat exchanger. In these applications, the exchanger is used to ensure that the energy from the exhausted air, which is saturated with water vapor, is transferred to the ambient supply air. This reduces the amount of energy consumed by the air heater.

Flucorrex AG, based in Flawil, Switzerland, is an international manufacturer of glass tube heat exchangers for malt houses. For the glass tube exchangers, Flucorrex uses glass tubes from Schott-Rohrglas.

“The quality and reliable supply, but also the good service we get from both the factory and the Swiss sales office in nearby St. Gallen, have really convinced us,” explains Managing Director Dr. Ulrich Willibald. His colleague and co-member of the management team, Dr. Detlef Bernt, is convinced that glass tubes offer not only resistance to corrosion and aging but also significant weight and price advantages over tubes made of chromium-nickel steel.

In lengths up to approximately 13' (4 m), the tubes are manufactured in Mitterteich, Germany, and delivered to Flucorrex in four different variations. With outside diameters ranging from approximately 0.79 to 1.58" (20 to 40 mm), the glass tube heat exchangers consist of modules that are fitted together. As many as 80,000 special glass tubes can be installed into one steel construction.