Baking better bread faster

That’s when they discovered that the Contherm scraped-surface heat exchanger cut the cooling time after dough scalding by six to eight hours. This dramatically improved the quality of the bread, cut lead times and allowed the bakery to fill orders precisely on schedule.

Fazer’s rye breads are made of a sourdough consisting of water, rye flour and a portion of sourdough culture from Finland. These ingredients are scalded and added to other ingredients.

“The scalding process is very important,” says Marie Isaksson in the Product Development Department at Fazer Brod. “Scalding makes the bread compact and moist. It extends the shelf life and gives the bread a hearty aroma. The bread is easier to slice and crumbles less. Prior to installing the two Contherm scraped-surface heat exchangers, the cooling process used to take varying lengths of time depending on the ambient temperature.”

Previously, the dough was cooled in large plastic troughs on the bakery floor. During the summer months when the temperature in the bakery rose with the outside temperature, the length of the cooling process was unpredictable. “With the Contherms, we now have a more consistent quality of the final products since there is now an exact temperature of the dough,” says Hakan Jonasson, Technical Manager at Fazer.

The two Contherms were installed at the beginning of the summer in 1999. Alfa Laval supplied the heat exchangers and Fazer constructed their own control system and did their own programming. “The Contherm installation not only improved quality and cut production time but improved the work environment in the bakery.” Gone were the problems with heat and humidity. And gone was the heavy manual work involved in handling and lifting the plastic troughs containing the 660 pounds (300 kilos) of dough from each batch. It also eliminated the time-consuming washing process. “The two Contherms are simple to clean,” continues Hakan. “This is essential in a process with high hygienic requirements.”

“We started by examining various alternatives to speed up the cooling process,” says Hakan. “Finally we decided on Alfa Laval’s scraped-surface heat exchangers. Their technique is well-proven. Alfa Laval is a well-known company with lengthy experience and we thought this was a good guarantee of quality. The solution was somewhat more expensive but, on the other hand, it was a more efficient and suitable solution. The entire installation was completed without a problem and the heat exchangers went right into production.”

Every day 32 tons of bread are baked at Fazer Brod in Lidkoping before they are distributed to grocery stores and other stores throughout Sweden. The plant has been in operation since 1982 and Fazer Brod is part of the Finnish Fazer Group, one of the leading foodstuff companies in theNordic countries.

The Contherm Scraped-Surface Heat Exchanger

The Contherm scraped-surface heat exchanger is vertically mounted and designed for the heating and cooling of particulate, sticky, viscous and crystallizing/phase-change processes. It is available in three sizes and can serve in a wide range of process stages including heating, cooling, slush-freezing, pasteurization, sterilization and crystallization. The Contherm can operate with any of the following media: steam, water, brine, ammonia, glycol, freon, thermal oil or liquid gases.

During operation the product is pumped into the lower end of the heat exchanger cylinder and is removed from the cylinder walls by scraping blades as it flows through the cylinder. This scraping action results in product heating or cooling with a high heat transfer rate without fouling. The scraping action continuously removes the product from the cylinder wall, thereby allowing the fresh product to be exposed to the heat transfer surface and providing high heat transfer. The heating or cooling media flows in the annular space between the cylinder and the insulated jacket. When liquid media or steam is used, a spiral coil is installed in the annulus to provide high heat transfer efficiency.

The Contherm Offers the Following Advantages

• Does not affect the taste, color or texture of the product
• Saves floor space
• Maximizes product recovery
• Optimizes cleaning-in-place and reduces the risk of contamination
• Offers easy maintenance and inspection
• Provides effective air purging

Alfa Laval’s Unique Customer Testing Center

The Contherm Product Center for Alfa Laval Inc in the USA is located in Newburyport, Massachusetts. The Contherm Product Center staff provides design, application and service expertise for heat exchangers for the food industries including the Contherm and Convap heat exchangers as well as sanitary plate heat exchangers.

Alfa Laval’s new Customer Testing Center offers customers testing capabilities for all products from the thinnest to the most viscous, from the smooth to the most chunky. In the laboratory customers can simulate processing conditions in a full-scale processing line. The laboratory consists of mixing equipment and a battery of six Contherms for testing evaporation, heating or cooling processes. A state-of-the-art rheology laboratory offers customers food analysis with valid data on the food products processed.