Cattes furnaces combine a gas heater with a catalyst holder – an apparatus in which catalyst samples are exposed to gas streams of varying composition, quantity and temperature.

In the gas heater, large quantities of gas with the desired composition are brought to high temperatures and passed through the catalyst sample in the catalyst holder.

The requirements for the gas heater are that

• no impurities get into the gas,
• sensitive components pass the heater section without decomposing,
• the gas meets the catalyst sample in as homogeneous a mixture as possible,
• quick changes in gas temperature and mixing ratios are possible.

The catalyst holder should

• ensure a constant temperature in the catalyst sample,
• provide defined measuring points for temperature control in the catalyst,
• ensure the transfer of the gases to the downstream analysis systems with a minimum loss of temperature
• allow easy sample changing.

The cat test furnaces from HTM REETZ largely meet these requirements.
Except for the high-pressure version, the material in contact with the gas consists mainly of quartz glass.