ATEX Retractor System TANKO-RT/-RTS
32/121
Translation - Operating/installation instructions 2020/01
3 Design and Function
Exceeding the temperature limit of 70 °C in the area of the limit switch can permanently endanger the
functional reliability of the limit switch, as the manufacturer specifies a maximum permissible ambient
temperature limit of 70 °C for the intended use. This can generally only be done on the limit switch near
the hydraulic pipe. A surface resistance thermometer monitors whether this temperature is exceeded.
At operating temperatures of over 70 °C, for the cleaning medium and/or the ambient temperature
within the container, the supplied pneumatic resistance thermometer must be mounted on the
pneumatic cylinder right next to the limit switch F, for power cylinder “extended”, and evaluated by the
higher-level plant controller.
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As soon as the temperature monitoring system detects a temperature near the limit switch (F)
of ≥ 66 °C, the retractor system must be placed in a safe state and all limit switches and throttle
check valves must be replaced with original spare parts before restarting.
The cause of the excess temperature must be determined and eliminated immediately.
–
The entire temperature monitoring system near the limit switch F “extended” must comply with the
ignition protection system b1, EN ISO 80079-37 in the currently applicable version, or equivalent.
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The provisions of EN 60079-14 regarding the selection and setup of electrical operating materials
must be observed.
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The temperature monitoring must be constantly and actively connected with the monitoring system,
including during the system idle state, during cleaning mode and during non-operation of the
retractor system (media and pneumatic connections closed with permanently sealed shut-off
fittings). According to the operating instructions, this ensures that the safety devices (limit switches)
required for explosive atmospheres are not exposed to damaging high temperature during
intended use.
Apart from the monitoring described above, it must be ensured that cleaning mode can only be started
if the moving internal fittings in the plant that move within the working area of the spray head are in
their rest position and are secured against being turned on again. This system must guarantee a high
level of safety.
Only plants (containers) with sufficient grounding and made of conductive material without an insulating
inner coating may be cleaned. The container outlet must be open during a cleaning process, i.e. no
accumulation of cleaning agent may occur.
For this, see
Section
and function diagram, as well as
Section 3.2.2
When the retractor systems are not in operation, the media and pneumatic connections must be closed
with permanently sealed shut-off fittings.
Application examples of the TANKO-RT and TANKO-RTS retractor systems
Tanks, silos, barrels, containers, pipes, dryers, centrifuges, agitators, vacuum tanks, spray towers,
container washing plants, fermenters, filters, mixing containers and horizontal dryers.