Buhler GAS 222.20 DH, Инструкции по сборке, установке и эксплуатации

Страница: 15 / 35

GAS 222.20 DH
6.1 Maintaining the Filter Element
The probes feature a particle filter which needs to be changed as it becomes dirty. Before changing the filter, unlock and raise
the weather hood.
To do so, disconnect the voltage supply and if applicable close the shut-off valve to the process or switch off the process.
CAUTION! Do not damage the rear filter seat.
NOTICE
Ceramic filter elements are very brittle by nature. Handle them with care, don’t let them
fall.
Filter elements made out of sintered stainless steel can be cleaned in an ultrasonic bath
and be used several times as long as both seals are still in proper conditions.
DANGER Toxic, corrosive gases
The measuring gas led through the equipment can be hazardous when breathing or
touching it.
a) Check tightness of the measuring system before putting it into operation.
b) Take care that harmful gases are exhausted to a save place.
c) Before maintenance turn off the gas supply and make sure that it cannot be turned
on unintentionally.
d) Protect yourself during maintenance against toxic / corrosive gases. Use suitable pro-
tective equipment.
DANGER Explosion hazard due to high liquid temperatures
Hot steam and hot sample gas cause in a high probe surface temperature. The highest
fluid temperature is approximately the maximum probe surface temperature.
a) Always ensure a safety clearance of at least 20 K between the fluid temperature
(steam, sample gas) and ignition temperature of explosive atmosphere (by measur-
ing and monitoring the temperature).
b) Also be sure to stay well below the smouldering temperatures of dust.
c) Observe the relevant requirements in standards regarding the max. permissible sur-
face temperature and ignition temperature of explosive atmosphere.
6.1.1 Replacing the downstream filter
– Unlock and lift up the weather hood.
– Turn the handle at the back end of the probe by 90° (handle must then be horizontal), pushing in slightly, and remove.
– Remove the dirty filter element and check the sealing surfaces.
– Before installing the new filter element, replace the seal on the handle plug (seal included with the filter element).
– Then carefully insert the handle with new filter, push in slightly and turn 90° (handle must then be vertical). Pull on the
handle to verify the filter element is firmly seated.
– With the filter removed, if necessary also need clean the inside of the sampling tube by blowing it out or using a cleaning
wand.
NOTICE
The weather hood can only be closed again when the handle is completely vertical. In or-
der to do so, loosen the hood from the locking supports by lifting slightly and then fold
down. Ensure that the hood lock clicks into place correctly.
13 Bühler Technologies GmbH BE460045 ◦ 10/2019