Baking and drying ovens have been workhorses in the food, textile, and paper industries for many decades – and many oven users have clung to decades-old equipment because profit margins can be low in their industry. Although many of these older ovens still function with roughly the same level of consistency, certain newer technologies can result in reduced operating costs and lower risks to production and personnel due to fewer shutdowns.

When selecting a flammability analyzer, it’s always a good idea to enlist the advice of a specialist in the field. Do not assume that the analyzer which was correct for a previous job will also be the right choice for another application. Whether new or similar, the specific details of each application need to be examined closely to prevent disaster.

The flame temperature analyzer measures the amount of heat given off by a pilot flame as it burns in an explosion-proof measuring chamber. The small, well-regulated flame heats the tip of a temperature sensor suspended directly above it.

Combustible gases absorb infrared radiation at certain characteristic wavelengths. A typical non-dispersive infrared (NDIR) detector passes a source of infrared energy through the sample and measures the energy received by one of two detectors. The active detector responds to wavelengths in the same band as the sample gas, while the other detector measures a reference to compensate for changes within the instrument.

Catalytic-bead sensors are constructed of two small wire coils covered with a catalyst. One coil is “active” while the other is rendered inert and acts as a reference. A flow of electrical current through the internal coils heats the catalytic coating to a temperature at which the active coil will react with many flammable vapors and gases. This reaction occurs in the form of surface combustion which in turn causes an increase in the sensor’s temperature. The resulting temperature change is converted into an LFL reading.

Although several different types of sensors are employed as LFL monitors, each has an appropriate application to which it is best suited.

Fires and explosions in what was thought to be “protected” equipment can occur without warning when a sensor is not capable of doing the job that had been assigned to it.

This is most often caused by a misunderstanding of the different available technologies.

Typical Flexographic Application Examples Include:

• Drying systems for printing lines
• Abatement systems such as oxidizers

Processes that use flammable solvents can develop explosive concentrations due to failure of coating, metering, ventilation or heating systems, adverse chemical reactions, and human error.

LFL monitors are used for safety as well as process efficiency, protecting the system from fire and explosion while also allowing operating at higher vapor concentrations to save costs.

There are important considerations when choosing an LFL monitor: Response Accuracy, Response Speed, Condensation Issues and Failsafe.

There are important considerations when choosing an LFL monitor: Response Accuracy, Response Speed, Condensation Issues and Failsafe. We've discussed response accuracy and response speed, let's look at condensation issues:

There are important considerations when choosing an LFL monitor: