Process Description; Tasks; Production Runtime; Procedures For Start And End Of Day - Grundfos AQpure Installation And Operating Instructions Manual

6.6 Process description

6.6.1 Tasks

The system performs a number of different tasks. The following
tasks are automatically performed by the system, when automatic
mode is active:
Task

Production

Filling of the external tank
Tapping UV light
Backwash of self-cleaning prefilter
Backwash of UF membrane
Internal CIP
Backwash of GAC filter
Low power control
PLC reboot
In semi-automatic mode all tasks performed in automatic mode
(except Low power control and
following tasks can be activated by the certified service staff:
Task
External CIP
Integrity test
Several of the tasks utilise the same components and are
therefore in conflict with one another. Two conflicting tasks
cannot be active at the same time.
In semi-automatic mode the system can be switched to manual
control. In manual control all components of the system can be
controlled individually.
Manual control is protected with a special password
and must only be used by Grundfos service
Caution
specialists.

6.6.2 Production runtime

The task Production is only running within a specified period of
time each day. This period of time is referred to as "production
runtime". The production runtime is site dependent and is in
general determined by the consumer patterns and the power
management setup. Production runtime will typically be during
the day when water consumption is largest and when solar power
is available. Outside the production runtime the system is in an
idle state or it is performing self-cleaning tasks.
The production runtime is a system parameter.

6.6.3 Procedures for start and end of day

When the system enters production runtime (start of day) or
leaves production runtime (end of day), a number of tasks is
executed in a specific order. Other tasks are not activated before
or in between.
Start of day
At start of day the following tasks are executed in listed order:
1. Backwash of GAC filter
2. Backwash of GAC filter
Please note that the system deliberately performs the same task
twice. Once the tasks have been performed, the system starts the
Production task and from this point activates tasks as specified in
section: 6.6.1 Tasks.
End of day
At end of day the following tasks are executed in listed order:
1. Backwash of GAC filter
2. Backwash of UF membrane
– The Internal CIP is followed by
prefilter.
20
See section
6.6.5
6.6.6
6.6.7
6.6.8
6.6.9
6.6.10
6.6.11
6.6.12
6.6.13
PLC reboot) as well as the
See section
6.6.14
6.6.15
or Internal CIP
Backwash of self-cleaning

6.6.4 System parameters

For safe and faultless functioning of the system a number of
parameters is required. A general parameterisation is done
during the Factory Acceptance Test (FAT) in the factory. The
parameterisation is adapted according to local conditions and
customer requirements during commissioning on site.
6.6.5 Production
This section refers to fig.: 6-8.
The task Production controls the filtration flow through the system
from feed water inlet valve (64) to the internal tank (46).
Activation
The following criteria must be fulfilled before the task is started:
• The time of day must be within the specified "production
runtime".
• Power must be available.
• None of the following tasks must be active:
– Backwash of UF membrane
– Backwash of self-cleaning prefilter
– Internal CIP
– External CIP
– Integrity test
• The internal tank (46) must not be full (applicable only if
external tank (ETS2) is used).
• The external tank (ETS1 or ETS2) must not be full.
• No active alarms.
If the system is switched into semi-automatic mode, the task is
automatically stopped. Once the system is switched back to
automatic mode, the task is automatically activated again.
The task can be active along with:
– Filling of the external tank
– Tapping UV light
Alarm handling
If an alarm is activated while the task is active, the following
sequence is activated:
1. The feed pump (GP1) is stopped. If present, the dosing pump
(GP5) is stopped as well.
2. All motor valves (MK) are closed.
The system remains stopped, until the problem is remedied and
the [Reset] button is pressed at the HMI. Alternatively, certified
service staff can reset the alarm in the service menu.
Production startup
When the task Production is activated, the pressure sensor
upstream the UF membrane is examined first. If the pressure is
below a defined critical value, it is likely that the UF membrane
has been drained. In this case the feed pump (GP1) is operated
with increased speed, until the UF membrane is filled again.
During the filling of the UF membrane the air inside the
membrane escapes from air release valve (24).
Production flow
The system has an adaptive control algorithm for the production
flow setpoint. The production flow setpoint is automatically
reduced in steps down to a pre-defined minimum value. This
increases the time period between the external CIP executions.
After an external CIP has been performed, the production flow
setpoint is set back to the pre-defined maximum value.
The adaptive control algorithm for the production flow setpoint
can be disabled by setting the minimum flow and maximum flow
parameters to the same value. Observe section:
parameters.
6.6.4 System