Functional Description - ProMinent MAKRO TZ Operating Instructions Manual

Functional description

5 Functional description
Pump
Functional description of the diaphragm
liquid end
Diaphragm rupture warning system func‐
tional description
16
The metering pump is an oscillating diaphragm pump, the stroke length of
which can be adjusted. An electric motor drives the pump.
The metering diaphragm (2) hermetically shuts off the pump volume of the
dosing head (3) from the outside. The suction valve (4) closes as soon as
the metering diaphragm (2) is moved in to the dosing head (3) and the
feed chemical flows through the discharge valve (1) out of the dosing
head. The discharge valve (1) closes as soon as the metering diaphragm
(2) is moved in the opposite direction due to the vacuum pressure in the
dosing head and fresh feed chemical flows through the suction valve (4)
into the dosing head. One cycle is thus completed.
1
2
3
5
4
Fig. 7: Cross-section through the liquid end
1 Discharge valve
2 Diaphragm
3 Dosing head
4 Suction valve
5 Diaphragm rupture signaller
The diaphragm rupture warning system monitors the leak-tightness of the
multi-layer diaphragm. Together with the diaphragm rupture sensor and
downstream analysis electronics, the multi-layer diaphragm forms the dia‐
phragm rupture warning system.
The multi-layer diaphragm has an expandable point (4) on its hole circle. If
an outer layer of the multi-layer diaphragm breaks, feed chemical pene‐
trates into it under pressure and inflates this expandable point (4). Conse‐
quently the pin (2) of the safety piston (1) presses against the diaphragm
(3) of the diaphragm rupture sensor signaller so that a contact signal
switches off the pump or triggers an alarm signal (customer installed!).
Moreover, the multi-layer diaphragm prevents feed chemicals escaping in
the event of diaphragm rupture.
P_MA_0029_SW