#22 - Portable Hydrogen and Oxygen Analysis – Part 3

Ceramics Industry

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.

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/

#16 - Portable Hydrogen and Oxygen Analysis – Part 2

The Nova Model 340WP Portable Oxygen & Hydrogen Analyzer is very useful for measuring atmospheres in ferrous heat treating applications.

Ferrous Annealing

Annealing for many kinds of steel has to be done under an atmosphere of about 10% hydrogen or better. This is in order to maintain the brightness and eliminate scaling. Exothermic generators are generally used for this atmosphere.

Transformer Steel

Figure 1 shows the use of the 340WP analyzer in an installation where transformer steel is being annealed. In most cases, after the laminations have been stamped out they must be annealed to obtain the proper soft magnetic characteristics. In this case, the parts are run through a continuous furnace and brought up to the proper annealing temperature. The atmosphere is introduced from an external generator. The drawing illustrates that the analyzer can be used to set the exothermic generator, to check for leaks in the system, and also for checking the proper atmosphere in the various zones of the furnace.

Figure 1

Annealing of Roll Steel

The coils of roll steel need to be annealed, which is usually done in a batch operation. In this case, the 340WP analyzer is invaluable in determining when the atmosphere has been replaced before the heat is applied to the annealing operation. The analyzer can be placed at the exhaust of the annealing chamber, and this way, by the lack of oxygen and the increase of the hydrogen it can be determined when it is safe to start applying the heat and begin the annealing operations.

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 340 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/

#11 - Portable Hydrogen and Oxygen Analysis – Part 1

The Nova Model 340 Portable Hydrogen and Oxygen Analyzer is useful for many heat treating applications. Some of these are considered below.

Copper Annealing

One of the first applications of the 340WP analyzer is for copper annealing. In this case, an atmosphere of 1 or 2% hydrogen is necessary to be sure that oxygen is not present. It’s also necessary that the hydrogen be kept low as high hydrogen will embrittle the copper.

The presence of a leak or oxygen getting into the furnace is detected by a low hydrogen reading. Oxygen itself cannot be detected after it has leaked into the furnace; it is consumed by the surface of copper and discolors it. The air leak is instead found by the low hydrogen reading. Experience has shown that at times the oxygen does not unite with the hydrogen and is still present. This is the reason the oxygen reading is necessary for complete analysis.

Copper Brazing

The 340WP analyzer is very useful for measuring atmospheres in a copper-brazing furnace. These atmospheres must be high in hydrogen in order to eliminate scaling and discoloration, as well as to ensure the proper fluxing of the solder.

In this case, the analyzer can be used both to measure the setting of the gas generator as well as for probing in various zones of the brazing operation. This ensures a proper atmosphere as well as aids in finding problems in atmospheres that are causing discoloration to the work.

Brass Melting

Figure 1 shows a standard type of brass melting pot. These measurements also apply to kiln melting but the older brass melting pot is shown as an illustration. In this case, the gas burner is placed at the bottom of the pot and the flame circulates up around the pot and over the top of the molten brass. The protective atmosphere to reduce the dross is produced by the flame itself. An experienced operator would look at the flame coming out of the furnace and thereby judge the amount of hydrogen in the atmosphere.

Figure 1 - Oxygen & Hydrogen Analysis in Brass Melting Operation

In practice however, even an experienced technician cannot tell whether it is 1% or 6% hydrogen. The hydrogen in this case is very important because if it gets too high it causes not only embrittlement but also produces voids in the castings. Here an analysis taken right inside the flame over the pot is what is necessary. Nova has quartz probes available for this measurement.

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 340 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/