The ceramics industry usually requires different process atmospheres than the metal-working and steel heat-treating industries. Ceramics generally require that the process atmosphere be oxidizing, that is, oxygen should be present. But this will depend on the type of glass or porcelain being worked.
Glass Tank
In the case of a glass tank, a fuel is burned to produce the heat required for melting the glass. Combustion efficiency is needed to obtain the proper temperatures. Combustion of the fuel also produces the required oxidizing atmosphere. Measuring hydrogen and oxygen helps to ensure and maintain these conditions. The Nova Model 340 Portable Oxygen and Hydrogen Analyzer may be used for this purpose.
The combustion fuel may not always be optimally mixed. Therefore, at low oxygen readings, hydrogen may still be present. This should be avoided by either adding more oxygen, or correcting the fuel mixing problem. The 340WP analyzer can also be used to detect and correct these unacceptable conditions.
Kiln Atmosphere
In the firing of ceramics, the atmosphere is important and will depend upon the type of ceramic being fired. Combustion efficiency is also a consideration, especially with the high cost of fuel.
Figure 1 illustrates a tunnel kiln with burners on the side, in which the adjustments of the individual burners or zones can be made by using a Nova 340WP analyzer. In this case, the atmosphere must be tested along the length of the kiln in order to detect burners that are not correctly adjusted. In some cases, air infiltration may be compounding the difficulties caused by a burner problem.
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| Figure 1 |
Blanketing Atmospheres
In some cases, an inert generator is used to supply a gas blanket over products sensitive to oxygen. For example, some high-performance production coatings require cure in absence of oxygen. In this case, the 340WP analyzer could be used to monitor such a generator to be sure that the oxygen is low and that the inert gases are therefore present.
Mixed Gases
It is becoming increasingly popular to supply an atmosphere of hydrogen mixed with nitrogen from pressurized gas cylinders instead of producing this atmosphere by an inert gas generator. The 340WP analyzer is very well suited for this, not only to monitor the mixing process and to be sure the proper amount of hydrogen is present, but to also ensure that no inbound air leaks are present. In this case, leakage into the gas distribution system or the furnace would give a poor finished result due to the presence of oxygen.
The Nova Model 340 Portable Hydrogen and Oxygen Analyzer is available with the following choice of ranges:
0-25.0% O2, 0-40.0% H2
0-2.0% and 0-25.0% O2, 0-40.0% H2
0-100 to 0-9,999 PPM O2, 0-40% H2
Which range is best for you depends on the application. Before purchasing a hydrogen analyser, we require that you tell us what other gases are in your sample. This will determine equipment suitability and design.
Model 340WP brochure…
We make gas analyzers for oxygen, hydrogen, carbon monoxide, carbon dioxide, methane, and many other atmospheric gases. We provide gas analysers for syngas, landfill gas, purity gas, biogas, and others.
Give Mike or Dave at Nova a call, or send us an e-mail.
1-800-295-3771
sales at nova-gas dot com
websales at nova-gas dot com
http://www.nova-gas.com/
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