16
Nozzle rod linkage 32 - EH
Function
During the pre-scavenging stage, both
the external solenoid in the supply line
and the external quantity or pressure
governor in the return line are open.
The attached solenoid is de-energized
and the valve used for needle actuation
is closed, the spring-loaded rod thus
keeps the needle in the bore of the
nozzle plate at the front of the feed pipe
closed so that the oil cannot reach the
furnace chamber too early. The pres-
sure at connection “C” is 0 bar or equal
to the ring main pressure if the connec-
tion “L” has been connected to a ring
main. The oil circulates from connection
“S” via the swirl chamber plate in the
nozzle through the feed pipe to the con-
nection “R”, thus warming it up to opera-
ting temperature. (For heavy oil only)
Operating voltage and type of current
are indicated on the attached coil. The
moment the attached solenoid is turned
on, the oil is released for needle actua-
tion; the rod is withdrawn, and the
nozzle needle is opened. During the
short time where the piston moves from
closed to open needle position, the
pressure at connection “C” is always at
least 2bar lower than the pressure at
connection “S”. From the moment on
where the piston reaches its final posi-
tion and the needle is opened fully, a
pressure is applied at connection “C”
which is as high as the pressure at con-
nection “S”.
The interruption of the power supply to
the attached solenoid causes the
needle to be closed by means of the
spring. The oil outflow on the nozzle will
stop immediately.
The pressure at connection “C” will go
down to 0 bar or reaches again the
same level as in the ring main if connec-
tion “L” is connected with the ring main.
The circulation from connection “S” via
the swirl chamber plate to connection
“R” will still take place. The temperature
of the feed pipe is thus maintained.
Service
Normally, the burner feed pipe is
maintenance-free.
The only moving part in the feed pipe is
the rod linkage used for actuating the
needle with the piston. After a longer
period, the O-rings could be worn out.
For replacement, complete O-ring sets
are available.
