Regenerating Iron Filter; Backwashing Filter - Autotrol Magnum Cv 942 Installation And Service Manual

Figure 5.10 Regeneration Complete
It is important to note that the numbers on the Salt Dial
represent "MINUTES" of water refill time. To determine
the total pounds of salt that will be used for a
regeneration, it is necessary to know the refill control
that is used in the conditioner. The refill control
determines the flow rate of water into the salt tank
during the refill cycle. Refer to the Salt Use Table 5.8 to
determine the total pounds of salt used per
regeneration for the various size tanks.
Table 5.6 Cycle Times for 942 Control
Cycle
Backwash
Brine/Slow Rinse
Purge
Refill
5.2.2 Regenerating Iron Filters - Model 942
Filter medias used in the water treatment industry
generally require only a periodic backwashing with
water to maintain their filtering efficiencies. These type
of filters would use the 942F control described in the
next section. Manganese greensand media, typically
used for iron removal, requires regular regeneration
with an oxidizing chemical, potassium permanganate
(KMNO ) similar to the regeneration of a water softener
4
with salt. This application requires the use of the Model
942 control.
Common Settings
Setting the Time of Day, Days of Regeneration, and the
initiation of a Manual Regeneration are as previously
described in this section.
Adjusting The Regenerant Setting - Model 942
Refer back to the previous heading in this section
Adjusting the Salt Setting - Model 942. Setting the
number of "MINUTES" of refill time determines the
amount of regenerant chemical used per regeneration.
Refer to the Regenerant Use Table 5.9 for the proper
setting based on tank size and the number of cubic feet
of media used.
Salt Dial
Indicator Knob
Time (Minutes)
17
95
9
2 to 24
25
NOTE: Only two sizes of refill flow controls are
recommended when the Magnum Cv Series control
valve is used in a manganese greensand filter system.
The Magnum control valve must be ordered with the
proper size refill flow control or changed in the field.
The incorrect refill flow control could underfill or overfill
the regenerant tank resulting in a system malfunction.
5.2.3 Backwashing Filter - Model 942F
Adjusting the Backwash Setting
The Backwash Dial (Figure 5.11) controls the backwash
time. With the Indicator Knob in the BACKWASH
COMPLETE position, rotate the Backwash Dial
counterclockwise at least one full turn to cancel out the
current setting. A light clicking sound will be replaced
by a heavier clicking sound when the previous setting
is cancelled. Once the heavier clicking is heard, the
new setting may be set by rotating the Backwash Dial
to the desired setting. The numbers on the Backwash
Dial represent "MINUTES" of backwash time.
Figure 5.11 Backwash Complete
Table 5.7 Cycle Times for 942F Control
Cycle
Backwash
Purge
Backwash Dial
Time (Minutes)
8 - 30
9