B2 Description Of Machine Modules; B2.1 Wash Zone; B2.2 Rinse Zone; B2.3 Prewash Zone - Electrolux WTM165ERA User Manual

B2 Description of machine modules
The machine consists of the following zones:
• wash zone
• rinse zone
and can be integrated with the following units:
• prewash zone
• energy recovery/steam suppression unit (CU)
• drying zone (DT).
B2.1 Wash zone
Water with the addition of detergent is sprayed on the dishes in the wash zone through an upper and lower wash arm
system. The purpose of this function is to remove all residuals of food from the dishes. Washing is carried out with
water circulating at a temperature of 55-65 °C / 131-149 °F.
B2.2 Rinse zone
Water with the addition of rinse aid is sprayed on the dishes in the rinse zone through a system of arms equipped
with special nozzles. The purpose of this function is to remove all residuals of detergent deriving from the previous
wash phase.
Rinsing is carried out with clean water coming from the water system, heated to a max. temperature of 80-90 °C /
176-194°F.
The high temperature ensures satisfactory drying and careful neutralization of bacteria. The addition of rinse aid
allows the water to easily run off the dishes, thus favouring the drying process.
An extra function called "Duo-rinse" can be implemented in the rinse module". The "Duo-rinse" is a device that par-
tially recycles the water coming from rinsing, spraying it on the dishes before the actual rinse.
In this way the rinse water is collected in a tank and sent by means of a pump to two specific arms equipped with
nozzles. This considerably reduces water consumption during the conventional rinse phase. The "Duo-rinse" is only
present in the modular rack-type dishwashers.
B2.3 Prewash zone
Water is sprayed on the dishes in the prewash zone through an upper and lower prewash arm system. The purpose
of this function is to remove the larger food residuals, preparing the dishes for the subsequent wash phase.
Prewash is carried out with water circulating at a max. temperature of 35°C / 95°F in order to prevent food residuals
(in particular proteins) from sticking to the dishes.
B2.4 Energy recovery/steam suppression unit (CU)
Some rack-type dishwasher versions can be supplied with an energy recovery/steam suppression unit called a con-
densing unit (CU). It consists of a fan and an air-water heat exchanger. By means of the fan, the steam present
inside the wash zone is exhausted and condensed thanks to the heat exchange with the cold water entering; the
condensed steam (water) is recovered in the wash tank. This also offers the advantage of heating the cold water
entering, recovering a part of the heat that would otherwise be dissipated into the environment.
B2.5 Drying zone (DT)
The dishes come under a flow of hot air in the drying zone, facilitating the water evaporation process. Drying occurs
with hot air at a temperature of 50-60 °C / 122-140 °F. This function can be added at the machine outfeed after the
rinse zone.
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