QUEENSLAND URBAN UTILITIES
QUU CONTRACT NO: C1112-022
LUGGAGE POINT STP/LUGGAGE POINT
OPERATION & MAINTENANCE MANUAL
Chp4Maintenance.doc
DRAFT: A 23-Jul-13
Page 4 of 36
4.2.4 Aqua-Screen
®
Chain Wear
Check the wear of the screen chains routinely. This can be done easily by removing the inspection
plates and measuring the pitch of the chain. The maximum permissible wear is 8 inches between
roller centers, that is, per pitch, after which the chains must be changed. To replace the screen
chains, contact ANDRITZ.
4.2.5 Aqua-Screen
®
Chain Tension
Check the tension of the screen chains. See figure 4-1. Elongation of the screen chain links tends
to lower the bottom point of the Aqua-Screen®. Beyond a certain degree of elongation, the angles
of the perforated plates start to rub on the base of the Aqua-Screen® or on the channel bottom.
Any unusual vibration or consistent hammering noise is a good indication that the chain requires
tensioning. A damaged or bent side seal plate may also indicate that chain tensioning is needed.
The best method of control and correction is as follows:
1. Drain the channel.
2. Remove two perforated screen panel plates. (Refer to § 4.3.1 for the procedure for
removing these plates.)
3. Rotate the perforated screen panel plates to bring these two openings to the lowest point of
return section of the chain loop (near the bottom of the channel).
4. Look through the openings and note the position of the chain rollers on the half moon plate.
The perforated screen panel plates run around the half moon plate at the bottom of their
loop.
5. Advance the perforated screen panel plates by short distances until a chain roller is at the
lowest point of the half moon plate.
CAUTION: Switch off and lock out/tag out the electrical switches of the two motors.
6.
Correct tension adjustment of the perforated screen panel plates implies two conditions:
a. The roller of the lower point must be in contact with the half-moon plate, as shown
on figure 4-1.
b. The roller immediately to the rear must be located about 13 mm to 19 mm from the
half-moon plate.
Luggage Point STP ST18 Pre Treatment (Aqua-Screen (Andritz) Operation and Maintenance Manual) General
Q-Pulse Id: TMS579
Active: 13/12/2013
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