daka’s Danish factories process a total of 750,000 tons of animal by-products every year. The company produces animal proteins of high ethical quality from the by-products of specific pig slaughterhouses. The animal proteins are used for mink feed and pet food. The company is primarily owned by cooperatives of slaughterhouses, which are in turn owned by farmers. The facility in this case is at Løsning in Denmark.
Production of animal proteins requires large quantities of steam. For that purpose daka used three large steam boilers. The boilers were supplied with feed water from old, worn out and uneconomical multistage pumps. The water level in the boilers was regulated by a feed water valve, which introduced a pressure loss into the system.
Energy was wasted. A bypass was installed on the pressure side of the pump.
Because the pumps had a high NPSH, booster pumps were used to raise the inlet pressure and combat cavitation.
The Grundfos Solution
Grundfos CR32 and CR45 pumps with EFF1 motors are installed. The feed water valve has been removed from the system. Instead, the boiler feed pumps are speed-regulated by frequency converters, which are directly controlled via the level sensor. Now, the water intake is immediately adjusted to changes in the water level in the boiler. The pumps only work when necessary.
These CR pumps are designed to have a low NPSH – cavitation is no longer a significant problem; the booster pumps can be eliminated.
Energy saving Efficiency is up to 40%.
This great increase is due to the new speed-regulated pump system and to the removal of the feed water valve. There are also savings from the elimination of the old booster pumps.
The annual savings amount to 288,912 kW/h.