Installer manual Fleck 2850 SXT - System sizing
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Ref. MKT-IM-030 / C - 12.05.2020
To calculate the system mass capacity:
M
capacity
= V
resin
× C
resin ex
with:
M
capacity
: system mass capacity [g as CaCO
3
]
V
resin
: volume of resin [L]
C
resin ex
: resin exchange capacity [g/L
resin
as CaCO
3
]
To calculate the system combined capacity:
C
capacity
= V
resin
× C
cor resin ex
with:
C
capacity
: system combined capacity [°f.m
3
or °dH.m
3
]
V
resin
: volume of resin [L]
C
cor resin ex
: corresponding resin exchange capacity
[°f.m
3
/l or °dH.m
3
/l]
To calculate the system volume capacity:
V
capacity
= M
capacity
/ TH
inlet
Or
V
capacity
= C
capacity
/ TH
inlet
with:
V
capacity
: system volume capacity [m
3
]
M
capacity
: system mass capacity [g as CaCO
3
]
C
capacity
: system combined capacity [°f.m
3
or °dH.m
3
]
TH
inlet
: inlet water hardness [mg/L as CaCO
3
or °f or
°dH]
Mandatory
If a mixing device is set on the valve before meter, use TH = TH
INLET
- TH
OUTLET
!
Having determined the previous capacity allows the operator to know the service cycle duration.
4.2.4
Valve configuration
Knowing the volume of resin, tank size and specifications of the resin, it is possible to determine
the required valve configuration. The resin specification will give the backwash velocity, as well as
the brine draw and slow rinse velocity that must be respected in order to ensure a proper
regeneration of the unit. From this data, determine the required backwash flow rate as well as the
brine draw and slow rinse flow rate. In most cases, the fast rinse flow rate will be the same as the
backwash flow rate, however for certain valve types the fast rinse flow rate will be the same as the
service flow rate.
To determine the backwash flow rate:
Q
backwash
= Fs
backwash
x S
with:
Q
backwash
: backwash flow rate [m
3
/h]
Fs
backwash
: backwash velocity [m/h]
S: Tank cross section area [m
2
]
