TM 10--3510--221--10
0003 00--1
WASHING/DRYING SYSTEM THEORY
OF OPERATION
0003 00
WASHING/DRYING SYSTEM
The washing/drying system performs all the operations related to washing, rinsing, extracting, and drying of the
laundry. All other systems on the LADS are used to support these operations. Operation of the washing/drying
system consists of the following sub--operations:
WASHING
The laundry is loaded into the drum through the front door. After the operator closes and latches the front door a
position switch (ZS100) mounted near the door will provide a signal to the control system. The control system will
provide a signal to extend the pneumatic lock (DN100) into the front door. This lock will remain extended during the
complete laundry cycle. A position switch (ZS101) mounted under the door lock will provide a signal to the control
system verifying that the lock is extended. After the operator selects the appropriate laundry formula, and starts the
laundry cycle, the washing operation will begin. The control system provides a signal to start drive motor (M100),
water pump (M101), and detergent pump (M102). The control system also opens ball valves (FV101 and FV106).
The basket starts rotating at tumble speed (approximately 36 revolutions per minute (RPM)). As the basket is rotating
the water pump draws water out of the wash tank and pumps it into the drum. The detergent pump draws a formula
specified amount of detergent out of the external supply container and injects the detergent into the drum. A flow
switch (FS100) is installed at the detergent pump outlet to verify that detergent is being drawn out of the external
container. Approximately one minute into the wash cycle the wash tank is empty and the drum is full of water. The
control system turns off the water and detergent pump and closes ball valves (FV101 and FV106). The basket
continues to tumble for approximately three more minutes as determined by the formula. At the end of the wash time
the control system opens ball valves (FV107 and FV109) and turns on the water pump. Wash water is pumped out of
the drum and into the still. While the drum is being drained the control system increases the drive motor speed until
the basket is rotating at low extract speed (approximately 300 RPM). The basket remains at extract speed for
approximately one minutes while the drum is drained. At the end of extract the control system turns off the drive
motor and water pump, applies the brake, and closes ball valves (FV107 and FV109).
FIRST--STAGE RINSING
The control system provides a signal to start drive motor (M100) and water pump (M101). The control system also
opens ball valves (FV103 and FV106). The basket starts rotating at tumble speed. As the basket is rotating the water
pump draws water out of the rinse 1 tank and pumps it into the drum. Approximately one minute into the rinse cycle
the rinse 1 tank is empty and the drum is full of water. The control system turns off the water pump and closes ball
valves (FV103 and FV106). The basket continues to tumble for approximately two more minutes as determined by
the formula. At the end of the rinse time the control system opens ball valves (FV100 and FV107) and turns on the
water pump. Rinse water is pumped out of the drum and into the wash tank. At this time the control system increases
the drive motor speed until the basket is rotating at low extract speed. The basket remains at extract speed for
approximately one minute while the drum is drained. At the end of extract the control system turns off the drive motor
and water pump, applies the brake, and closes ball valves (FV100 and FV107).
SECOND--STAGE RINSING
The control system provides a signal to start drive motor (M100) and water pump (M101). The control system also
opens ball valves (FV105 and FV106). The basket starts rotating at tumble speed. As the basket is rotating the water
pump draws water out of the rinse 2 tank and pumps it into the drum. When the control system determines that 65
gallons of water has been moved out of the rinse 2 tank it turns off the water pump and closes ball valves (FV105 and
FV106). This occurs approximately one minute into the rinse cycle. The basket continues to tumble for approximately
two more minutes as determined by the formula. At the end of the rinse time the control system opens ball valves
(FV102 and FV107) and turns on the water pump. Rinse water is pumped out of the drum and into the rinse 1 tank.
