Bosch TCA640 Series Repair Instruction page 39

4.5.3 Cleaning
The Cappuccino / Caffeelatte frother can be disassembled for
cleaning without a tool.
All individual parts can be cleaned with a mild detergent solution and
soft brush.
4.5.4 Function
Steam is conveyed into the Cappuccino / Caffeelatte frother (2) via the
steam pipe (1), flows through the frother and generates a low
pressure in the intake component. This low pressure is equalised by
air flowing through the openings in the inlet valve (6), or by milk which
is drawn through the intake hose (4).
The rotary controller (5) regulates the air intake and milk flow. In the
CAFFELATTE area only milk is drawn in. By rotating the controller,
the flow rate and therefore the temperature of the milk can be varied
between 50°C and 75°C. The air supply is closed in this position.
In the CAPPUCCINO area milk and air are drawn in. By rotating the
controller, the flow rate of the milk and the air supply can be varied.
This affects the temperature and consistency of the milk froth.
The milk is frothed when the milk proteins mix with air. Heated by the
steam, the milk froth flows out of the outlet (3) of the Cappuccino /
Caffeelatte frother.
58300000120060_ARA_en_c.doc – 18.09.09 Seite 39 von 95