Operating Manual for
FAN Press Screw Separator PSS 1.1-300
29
14
PROBLEMS - TROUBLESHOOTING
WARNING
Troubleshooting should only be performed by appropriately qualified personnel.
It is very important for you to familiarize yourself with the
“
normal
”
operating condition of the separator
during your application.
“
Normal
”
includes the discharge speed in direct connection with the desired DM
content of the solid cake. The DM content can be adjusted via the position and number of weights on
the lever arm of the output regulator. You will need to incrementally vary the settings to determine the
optimal and for you
“
normal
”
operating condition. It is also necessary to adjust the pump throughput in
order to determine the optimal capacity utilization of the separator for the
“
normal
”
condition. The efflu-
ent discharge and throughput represents another factor that can be evaluated.
However, since the consistency of the supply medium can change over time, you must expect that the
“
normal
”
operating condition of the machine in your application will also change.
If major changes with respect to the
“
normal
”
operating condition occur over a prolonged period of time,
it is important to determine the precise cause. The search for possible sources of error is simpler when
the principle and functioning of the FAN separator are sufficiently well understood.
14.1 PRINCIPLES OF A
“
NORMAL
”
OPERATING CONDITION
The auger of the separator has a defined diameter over its length and is adapted to the screen cylinder.
The auger and screen diameters are very precisely adapted to each other, and this relationship must be
maintained to ensure optimal operation of the separator.
The open drainage of the influent takes place in the inflow area of the screen; in other words, the water
not bound up in solid matter via capillary action is removed. In the press area, where the solid cake
forms, water bound up via capillary action is pressed out. If the influent contains no solid matter, no solid
cake is formed as well as no transport or continuous discharging of the cake. In principle: the higher and
more uniform the incoming concentration of solid matter, the larger the discharge speed of the solid
cake from the mouth piece.
The uniformity of the influent directly determines the discharge speed of the solid cake. To achieve suf-
ficient homogenization and uniformity of the solid matter in the liquid, it is necessary to use a stirrer that
is adapted to the throughput and situated in the inflow tank before supply of the medium to the separa-
tor. The use of a bypass or overflow line at the inflow element of the separator helps ensure that the
separator only receives the optimal volume of medium for the process without producing excess pres-
sure in the separator. The solid cake formed in the separator produces a self-cleaning process for the
screen, thereby ensuring optimal operation of the separator.
This self-cleaning effect of the screen is significantly influenced by the working gap between the screen
and the auger. Wear on the screen or on the outer edges of the auger blade can change this working
gap and negatively impact the self-cleaning process as well as the
“
normal
”
operation of the separator.
Indications of possible deviations from the
“
normal operating condition
”
of the separator as well as pos-
sible causes and remedies are provided in the following table to assist you in troubleshooting problems.
