Integrierte Vermeidung und Verminderung der Umweltverschmutzung

Chapter 3
Blanching (E.2)
Drum and belt blanchers are used in manufacturing deep frozen vegetables. Energy
consumption depends on, not only the type of blanching device, but also the type of subsequent
cooling step. Typical energy consumption levels are shown in Table 3.36 and Table 3.37.
Energy carrier Approximate consumption
Hot water (kWh/t frozen vegetables) 0
Steam (t/t frozen vegetables) 0.16
Steam pressure (bar) 7
Electricity (kWhe/t frozen vegetables) 0.5 – 1.3
Table 3.36: Energy source and consumption for drum blanching in the deep freezing of vegetables
[32, Van Bael J., 1998]
Energy carrier Approximate consumption
Hot water (kWh/t frozen vegetables) 0
Steam (t/t frozen vegetables) 0
Steam pressure (bar) 0
Electricity (kWhe/t frozen vegetables) 0.5 – 1.3
Table 3.37: Energy source and consumption for countercurrent water cooling of vegetables
processing
[32, Van Bael J., 1998]
Furthermore, the electricity consumption for the production of ice-water is included in the
electricity consumption shown for deep freezing. For example, in terms of energy consumption,
the belt blancher with water cooling has the lowest total consumption. The heat released by the
cooling of the product in the cooling zone is used to preheat the vegetables. In this way, less
steam is necessary for blanching. Table 3.38 shows the energy carrier and consumption for belt
blancher with water cooling in vegetable processing and Table 3.39 shows the energy carrier
and order of magnitude indicators of the belt blancher with air cooling in vegetable processing.
Energy carrier Approximate consumption
Hot water (kWh/t frozen vegetables) 0
Steam (t/t frozen vegetables) 0.09
Steam pressure (bar) 7
Electricity (kWhe/t frozen vegetables) 2 – 9
Table 3.38: Energy carrier and consumption for a belt blancher with water cooling in vegetable
processing
[32, Van Bael J., 1998]
Energy carrier Order of magnitude indicators
Hot water (kWh/t frozen vegetables) 0
Steam (t/t frozen vegetables) 0.16
Steam pressure (bar) 7
Electricity (kWhe/t frozen vegetables) 7 – 30
Table 3.39: Energy carrier and order of magnitude indicators of a belt blancher with air cooling in
vegetable processing
[32, Van Bael J., 1998]
With regard to electricity consumption, the drum blancher for countercurrent water cooling has
the lowest consumption. The water consumption for such an installation is rather high. The use
of heavy duty fans (60 kWe) in the belt blancher with air cooling, make the electricity
consumption high for this type of operation [32, Van Bael J., 1998].
RHC/EIPPCB/FDM_BREF_FINAL January 2006 177