5.2.1 Pre-flushing
Before the actual product metering starts, the rinsing valve
(
Ä
Chapter 4 ‘Layout’ on page 39 , Fig. 4 , no. 15) opens for flushing the system
internally with water. At the same time, the relevant valve of the machine-end valve
manifold block (e.g. M1) (
Ä
Chapter 4 ‘Layout’ on page 39 , Fig. 4 , no. 18) opens.
Fresh water now flows from the water inlet through the mud guard
(
Ä
Chapter 4 ‘Layout’ on page 39 , Fig. 4 , no. 12) and flow sensor (
Ä
Chapter
4 ‘Layout’ on page 39 , Fig. 4 , no. 13) into the rinsing valve, from there through the
valve manifold block on the product side (
Ä
Chapter 4 ‘Layout’ on page 39 , Fig. 4 , no.
9), on into the valve manifold block at the machine side and through the metering line into
the washer extractor.
The water flow is monitored by the flow sensor.
This process ensures that there is adequate water flow pressure and, thus, that reliable
flushing is possible. After the preset flush time has elapsed, the rinsing valve closes again.
5.2.2 Metered quantity
Depending on the stored washing programme parameters, a valve on the product-
end valve manifold block (e.g. P1) then opens and both metering pumps
(
Ä
Chapter 4 ‘Layout’ on page 39 , Fig. 4 , no. 4) start, provided that the
relevant connected suction pipe is in the product container, and there is sufficient product
available.
In the case of a product container being empty or due to other faults, such as pipe
blocking or pump failure, the metering is stopped by the control unit due to the preset
proportioning time being exceeded, and a fault signal is output. A fault signal is also
output when an empty signal is received from one of the connected suction pipes.
During metering, the product is pumped from the suction pipe into the product-end valve
manifold block by the pumps, on to the machine-end valve manifold block and through
the metering line into the washer extractor. The quantity of product flowing through is
monitored by the oval gear meter (
Ä
Chapter 4 ‘Layout’ on page 39 , Fig. 4 , no. 8),
and the signals are evaluated in the control unit. In order to increase metering accuracy, a
pump is switched off shortly before the end of metering, thus reducing the flow rate. When
the required metering quantity has been reached, the pump is stopped, and the valve of
the valve manifold block on the product side closes.
If another product is required from the same washer extractor, this product is only metered
after a variable intermediate flush, lasting at least 2 seconds, has been carried out.
Function description
41 MAN046590 Rev. 6-03.2022
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