BUCHI DuMaster D-480 - Manual (Page 221)

Operation Manual D-480 ©BÜCH Labortechnik AG
8 - Maintaining the instrument 221
Emptying reaction tubes
Requirements:
Before starting work, the following requirements must be met:
 The reaction tubes have been removed from the furnace.
 The reaction tubes have cooled down.
 Keep a tube extractor ready.
Safety instruction
Strictly observe the safety instruction "Emptying the reaction tubes" under Warning notes during
operation (on page 24).
Emptying the combustion tube
Proceed as follows:
 Insert the tube extractor into the combustion tube. After clamping the crucible tongs in the ash
crucible, pull the ash crucible out.
 Empty the ash crucible.
 Empty the copper oxide out of the combustion tube.
 Remove the wire mesh ronde and the spacer out of the combustion tube.
 Remove the CuO dust out of the combustion tube by means of a damp cloth.
 Dispose of the chemicals according to the relevant disposal categories.
Emptying the reduction tube
Proceed as follows:
 Remove the silver wool. You can re-use the silver wool if the surface is still shiny and silvery.
 Remove the copper and copper oxide.
 Place the reduction tube upside-down on a soft surface, e.g. cork.
 Tap on the reduction tube. The exhausted tungsten in the form of WO
3
slides slowly out of the
tube.
 Remove the wire mesh ronde and the corundum balls.
 Remove the WO
3
dust by means of a damp cloth.
 Check whether a salt crust is visible in the tube. Remove the crust with a suitable solvent.
 Dispose of the chemicals according to the relevant disposal categories.
Emptying the post combustion tube
Proceed as follows:
 Remove the silver wool. Usually, the silver wool has turned to black/grey and is used-up.
 Remove the corundum balls.
 Remove the CuO and the Pt catalyst.
 Remove the corundum balls.
 Remove the wire mesh ronde and the spacer.
 Remove the CuO dust and, if applicable, the crust of salt by means of a damp cloth.
 Dispose of the chemicals according to the relevant disposal categories.