January greetings from a new guest columnist! I am a mechanical engineer with 27 years of experience designing, troubleshooting and inspecting industrial combustion and heat-transfer equipment. As a consultant, I specialize in combustion safety (NFPA 86 “Ovens and Furnaces” committee) and air pollution control (19 U.S. Patents).

MostIndustrial Heatingreaders are familiar with the U.S. Patent and Trademark Office (USPTO) and its role in protecting the intellectual property (IP) of business enterprise. Patents are a significant financial investment for most companies, so innovations are typically not patented unless a substantial financial benefit is anticipated. Nevertheless, it is obvious from a review of the patent literature that the great majority of patents are never commercialized – up to 95% by some estimates.

With regard to furnace-related inventions, the patent office has seen a downward trend in recent years. Examining the figure below, one can readily see that against a variable backdrop of all utility patents (averaging approximately 150,000 patents per year over the past 10 years), the number of furnace patents rose slightly (to almost 200 issued in 2000) and then fell dramatically (to less than 50 issued so far in 2007 at press time). Also noteworthy is the comparison between two seemingly more glamorous technologies (mobile phones and fuel cells) where furnaces held the lead in the late 1990s, but then surrendered decisively in 2002 to the other two fields, which are experiencing more rapid growth in patented IP.

The declining trend is also consistent for furnace patents that are focused on safety or air-pollution control. A five-year rolling average of these types of patents held steady at three to four patents per year from 1990-2002, but only three such patents were issued in the five succeeding years combined.

A furnace safety trend that will not be a surprise to readers is the move toward programmable logic controllers (PLCs) versus hardwired systems to initiate safety shutdowns. NFPA 86 first recognized the growing acceptance of PLCs by addressing their usage in its 1990 edition. As late as the 2003 edition, it continued to require that such PLCs be specifically listed (by UL or another certification entity) for combustion safety service. With the 2007 edition, this requirement was relaxed, largely because such listings were eliminated several years ago.

The benefits of PLCs over hardwired logic are many – complex logic involving multiple sensors or processing steps; easier inspection and validation of logic elements; detection of local jumpers or defeated safety switches; password security for management of change.

However, the patent record for PLC safety control of industrial furnaces is sparse – none since the mid-1990s. From my perspective, I see these trends as a call to innovation! IP anyone?IH