Dosing - BRAVILOR BONAMAT FRESHONE (G) Operating Principle

1.3.5

Dosing

Dosing takes place when:
D The float is in the highest position.
D The second temperature sensor measures a temperature that is higher than the blocking temperature.
D Pressing a selection button starts the pump motor (Fig.5) at a certain speed (rpm) for a given amount of
time based on the programmed amount.
Fig. 5 Pump motor + rotor
D The pump rotor rotates in the water−filled pump chamber.
It is shaped by the bottom of the float tank and the bottom of the pump housing (Fig.6).
D The pump rotor pumps the water from the pump chamber through the siphon hose at the bottom of the
boiler.
D This presses the hot water out of the boiler.
D The float and the magnetic valve ensure that the correct level of water is maintained in the float tank and
pump chamber.
The volume of moved liquid (yield) is mainly determined by the time and speed of the pump motor. The time
that the motor is on is controlled by the software and is very accurate. The number of revolutions a motor
rotates is measured by an active revolution counter. Fig. 7 shows that a disc is mounted on the shaft of the
pump motor (A = Encoder). This disc rotates at the same speed as the pump rotor. The encoder rotates be-
tween a light sensor (B) interrupting the light beam each time. The interruption of the light beam is converted
into pulses that can be read by the electronics.
Fig. 7 Encoder
This active control of the rotational speed guarantees that the number of revolutions per minute and
therefore the water yield remain constant while the pump motor is on.
Selecting the dosed hot water:
D This machine has a hot water selector.
D This component (Fig.8) enables the dosed water in the boiler to be dosed in at least three directions and
at most six directions (depends on the type of machine).
Fig. 9 Water selector internal
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Fig. 6 Pump housing
Fig. 8 Water selector
Fig. 10 Water rotation disc