oventrop Toc-Duo-3 Bedienungsanleitung Seite 11

Nomogramm:
Oil capacity Inner pipe
in l/h diameter in mm
min.
Velocity of the heating oil during
operation according to DIN 4755:
02. to 0.5 m/s
*Avoid dimensions of less than 4 mm
Examples:
a) For a pump capacity of 30 l/h (about 300 kW), with
a medium suction speed of 0.3 m/s, a pipe of 8 x 1
mm with an inner diameter of 6 mm is required.
b) A small installation with a heat output of 30 kW,
corresponding to a flow rate of 3 l/h, is equipped
with a pipe 6 x 1 mm with an inner diameter of 4
mm. The velocity is very low then (about 0.07 m/s),
but possible airlocks are very small and do not
cause malfunctions.
Suction and pressure operation
The heating oil filter with deaerator must not be used
under pressure, i.e. behind a feed pump in the supply
pipe. This is not sensible as air is only emitted in
suction operated systems. According to DIN 4755 it
must be ensured that in closed pipe sections a rise in
pressure due to an increase in temperature of the hea-
ting oil must be balanced off (e.g. by installing a pres-
sure compensation device). Alternatively, closed pipe
sections can be avoided by renouncing check valves.
Increased pressure can lead to damage of the heating
oil filter with deaerator and other installed equipment.
Air pockets in the filter cup of the heating oil filter:
The heating oil is filtered before deaeration and during
Oil velocity
this process it is possible that some of the air in the oil
in m/s
is retained by the oil moistened filter insert so that an
air pocket forms in the filter cup (1).
As the inside of the filter insert is filled with oil, the in-
stallation continues its operation. This is especially
noticeable where a large portion of air is in the oil or
only small quantities of oil are consumed (10 kW ~ 1 l
oil/h). A sinking of the oil level is also possible during
burner operation.
Filling height in the deaerator case:
Depending on the working conditions, different filling
heights may develop in the lower part of the deaerator
case (2).
This chamber may also be filled completely, e.g. if no
gas emissions exist in the case of a tank located at a
higher level. The existing air may dissolve in the heating
oil in the circuit between the burner pump and the
chamber of the deaerator.
If working conditions change, e.g. by a sinking oil level
in the tank, a new air cushion may grow.
In case of heating oil in the upper part (3) with the se-
curity float, the heating oil filter with deaerator has to
be replaced.
Parallel installation of several "Toc-Duo-3"
If higher nozzle capacities than 110 l/h are required, it
is possible to install two or more heating oil filters with
deaerator in parallel. It must be ensured that the ma-
ximum return flow does not exceed 120 l/h per instal-
led heating oil filter with deaerator. The return flow is
the pump output minus the volume of burnt oil.
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