Chapter 2. Safety
PELLERIN MILNOR CORPORATION
The tunnel will jam if it transfers without enough water in each module.
Do not attempt to “fix” a low water level condition by holding the float lever up mechanically or
by merely readjusting the level switch. (With float-type level switches, cutting off the float rod
above the two top clips will discourage readjusting.) Instead, check for logical reasons for loss of
water flow (shut off water valves or pumps, lint-blocked pumps or strainers, etc.).
Make sure the float tube connection is not blocked with lint, as this can cause the Mentor
™
controller to think the water level is correct when it is not. Periodically purge each float tube
connection with air as explained in
How to Purge Float-tube Type Level Switches in the service
manual.
Weir boxes must be checked periodically for lint build-up. If the water flow through the weir box
is reduced, wash quality will diminish, the blocked module may overflow opposite the flow of
incoming water, and the water level may become too low for a safe transfer in any modules that
depend upon water from the blocked module.
Water levels are controlled by weirs as explained in
Using the Water Flow Features of the Milnor
Continuous Batch Washer
in manual MATCBWTRAE. This section also explains how to set the
level switches.
2.2.1.2. Correct Load Sizes—Because the Milnor
®
CBW
®
tunnel washer is usually able to transfer
occasional loads much larger than its rated capacity, the load sizes actually employed are
generally dictated by the capability of the extracting equipment (press or centrifugal) and the
material-handling equipment after the tunnel.
However, exceptions to this rule include—but are not necessarily limited to—“stiff jeans” or
similar products that do not readily absorb water, certain new goods, and goods that are
lightweight yet bulky (e.g., micro-filament 100% polyester barrier goods), etc. The load sizes for
such goods must be reduced proportionately, similar to the proportional reduction that must be
observed in washers and washer-extractors.
Multiple or repeated over-size loads can cause jams. Monitor and frequently recalibrate the load-
sizing method in your plant. The tunnel can often handle a single “double-size” load (usually
caused by a rail or loading conveyor malfunction) without incident—although a fault will likely
occur in the press or centrifugal extractor. However, repeated multiple loads will cause a jam,
especially in tunnels with date codes prior to Mildate 88297 (December 15, 1988). This is less
likely (but not impossible) with tunnels manufactured on or after this date because newer
machines have a photo-eye in the load scoop to prevent transfer when the entire load has not
flushed into the first module.
Jams can also be caused by insufficient wet-down or flushing water in the first module. Check the
reuse water flush pump, the level switch setting in the first module, and the minimum
commanded time for the flush valve to remain open. This minimum time is controlled by output
timer CRST2.
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