58300000111195_ARA_en_f.doc – 02.06.09
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5 FUNCTIONS
5.1
The perfect espresso
A genuine espresso is prepared according to a specific extraction
process in which the water is forced under high pressure through
finely ground coffee in order to release all the flavours.
The excellent quality of the result in the cup depends on the
selection and composition of the raw coffee from different countries
of origin, the degree of roasting, the fineness of the grinding and the
extraction method: Applied pressure, water temperature and
extraction duration.
A perfect espresso can be identified by its distinctive taste, intensive
flavours and a dense body, refined by a crema of perfect consis-
tency.
5.2 Operating
principle
Water and coffee beans are kept ready in the storage containers for
the preparation of coffee. When the product has been selected, the
coffee grinder begins to grind the beans. Ground coffee is metered
into the brewing module. The coffee grinder stops after a time
allocated to the quantity. The brewing process begins when the
brewing module moves into the upper end position. When this
position has been reached, the water pump begins conveying water.
Water is drawn out of the tank via the flowmeter. The water flow
causes the fan impeller to rotate in the flowmeter, causing electrical
pulses to be generated. The running time of the pump is specified by
the number of the pulses. The pump conveys the water through the
heater at a pressure of 5–8 bar. Depending on the selected product
(coffee, hot water or steam), the water is heated up to a temperature
between 82 °C and 130 °C before it is fed either to the steam pipe
via the two-way valve or conveyed into the brewing module via the
drainage valve.
The sequences are monitored by sensors and microswitches. All
functions are controlled and interlinked via the logic module. All units,
such as motors, pump, heater, are supplied with power via the power
module.
5.3
Warming the cups
The warm exhaust air from the coffee heater is used to warm the
cups. The air rises and flows through openings in the cup rack. There
is no active heating element for warming the cups.
Grinder
Water tank
Brewing
unit
Reed s
w
it
ch
2-way
valve
Tray
cont
act
Service door
Pump
Ground coffee slot
Steam pipe
Logi
c
Grinding correction
Pow
er
Extract. pos.
Heater
Net
filter
