Efficient is an adjective defined as “achieving maximum productivity with minimum wasted effort or expense.” Society as a whole typically strives to achieve and apply “efficiency” to all facets of life. It could be personal: I want to be efficient about getting my household tasks done; I want my home to be energy efficient; I have a fuel-efficient vehicle. Or it could be professional: I perform my role at work very efficiently; The products we manufacture are the most efficient on the market; Our building is LEED certified.
A Desire for Efficiency and Innovation is Innate in our World
Even with this ever-increasing modern focus and awareness on protecting the environment, which inherently promotes efficient developments and activities, I think we need to recall that a focus on efficiency is not at all a new or modern concept. Efficiency is as innate to our planet and culture as watching a stream or river flow downhill.
Society’s desire for efficiency has driven innovation since the beginning of time, starting with basic life or survival developments including stone tools, the Gregorian calendar, alphabetization, the sailboat, sextants, gunpowder and the compass. Perhaps we should also mention the wheel and note that the wheelbarrow followed the wheel by thousands of years in China and another 1,000 years subsequent to that before it surfaced in Europe.
If we look to agriculture, we must consider the moldboard plow, which greatly extended the land that farmers could till. Nitrogen fixation, notably the Haden-Bosch process, which made modern ammonia-based fertilizers available, significantly increased crop yields. There is also the concept of crop rotation and the Archimedes screw, which provided irrigation for fields from nearby streams and canals.
If we consider advancements and developments in the medical field, we would be amiss not to acknowledge penicillin, vaccinations and anesthesia, which debuted in 1846 and began to distinguish surgery from medical torture. Prior to the development of corrective lenses, many people were literally handicapped by their inability to see letters and numbers as clearly as others. Some might even claim the adoption of corrective lenses amounted to the largest one-time IQ boost in human history by expanding the pool of potentially literate people.
If we focus on industry and processes, we must consider the printing press, paper, the cotton gin, the steam engine and the internal-combustion engine. Let’s not forget cement, the drilling and refining of oil and, of course, industrial steelmaking. Mining and metal refining played a key role in technological progress, and the blast furnace is one of the first examples of continuous production.
Innovations pertaining to human comfort and significantly improving the efficiency of society in general would include sanitation systems, the telegraph, electricity, refrigeration, the telephone, radio and television. With the evolution of semiconductor electronics, technology as we know it today grew by leaps and bounds with the development of the personal computer, smartphones, the Internet and satellites.
Knowledge has never been more readily available. Behind all of these innovations there is one common denominator: an acceptance and even an embrace of change.
How Efficiency is Measured
Efficiency, by one technical definition at least, is defined as “the ratio of the useful work performed by a machine or in a process to the total energy expended or heat taken in.” In some cases, on a superficial level, this can be a very direct and digital calculation. However, a true measure of efficiency is typically more detailed and qualitative.
Efficiency allows you to save time and may be realized by reduced cycle time, less downtime for maintenance and ultimately higher production output. This, of course, can be quantified. Efficiency allows you to save money, typically highlighted by using less energy input per unit of output. This can also be quantified by simple return on investment (ROI) or payback calculations. However, these calculations are not a detailed approach resulting in true cost of ownership or life-cycle cost, which will be discussed later.
Less-tangible efficiency measures that are more difficult to quantify are things like product quality, market leadership recognition and carbon-footprint reduction. Even more challenging measures of efficiency are results of process improvements.
Two Japanese management concepts come to mind in this regard: Kaizen and Kaikaku. Kaizen is evolutionary and focused on incremental improvements, while Kaikaku is revolutionary and focused on radical improvements. The Kaizen mindset is such that not a single day should go by without some kind of improvement being made somewhere in the company. This type of focus on processes and the associated efficiency gains will result in improved communications, the ability to ensure accountability and the right environment, which are all a challenge to quantify.
Kaikaku, on the other hand is radical change. Carburetors on internal-combustion engines were incrementally improved for over 100 years, but then there was a revolutionary change when direct fuel injection was universally accepted because it dramatically improved efficiency. Regardless of the metrics used to measure efficiency improvements, I think it is clear that the path to achieve efficiency starts with a mindset that embraces change.
How does efficiency and innovation apply to the heat-treat industry?
The heat-treating industry worldwide has embraced many changes to improve efficiency and reliability. Improvements in the basics of insulating heat-treat equipment come to mind. Refractory materials like traditional firebricks have continuously been improved to augment their effectiveness and extend their useful life. Fiber insulation panels now offer an attractive alternative.
Perhaps the most dramatic changes have been in the area of instrumentation and controls. Advances in temperature and atmosphere controls have been and continue to be of major significance. The precision now available in current controls offers furnace operators improved quality outcomes and reliability. Advances in control algorithms – made possible with the introduction of programable logic controllers and networked computers – have resulted in tangible cost savings.
Burner technologies, relatively unchanged for most of the first 75 years of the 20th century, have seen both incremental and revolutionary changes since then. The seemingly simple combination of air and natural gas to produce heat is not so simple.
Burner companies have made amazing advances beginning with the last decades of the last century and continuing today. Combustion efficiencies of less than 25% with naturally aspirated burners were common. The widespread introduction of recuperators, both internal and external, were the first major improvement. Along with forced-air burners, the recuperated systems routinely improved the efficiency to the mid-50% range. Very simply, those advances were made possible by using waste exhaust heat to preheat the combustion air.
Today, even more advanced systems are available. For indirect heating, single-ended recuperator burners (SER) and exhaust-gas recirculator (EGR) systems can achieve efficiencies of around 70% or higher. EGR systems offer the added advantage of reduced emissions, which for many companies is a corporate goal, if not mandate. Both of these advanced burner systems employ complex recuperators with enhanced geometric configurations within the burner assembly. Many employ advanced materials such as silicon carbide to further advance combustion efficiency.
Silicon carbide is also being employed for radiant tubes because it has the capability of higher heat fluxes. This, in turn, means that more heat can be transferred to the load in less time, which reduces cycle time and, in effect, increases a given facility’s capacity. The dramatic increases in productivity are well established and have a direct result in overall cost savings. Other efficiency improvements are now available, such as internal and external fins that have been touted (in some cases) to improve efficiencies well into the range of double-digit percentile gains.
Can we afford to be efficient?
Perhaps the question to ask is: Can we afford not to be efficient? While more durable and efficient technology and equipment typically has a higher initial cost, minimizing first cost does not necessarily result in lower operating costs or lifetime costs and may actually be to the contrary.
As previously mentioned, simple return on investment (ROI) analyses or payback calculations are typically performed when considering the procurement of high-performance capital equipment. A maximum of a seven-year payback is required, but three to five years is more the norm. Some companies even have investment policies that require one- to two-year paybacks, which obviously precludes many opportunities for improvements.
A more sophisticated approach is a present-worth analysis, which establishes a present-time value of all future cash flow by discounting the costs. A typical timeframe for this approach is 20 years, which is a widely accepted industry standard to predict the usable life of equipment. Considerations in this approach include the future cost of energy, future maintenance costs, replacement costs and future interest rates.
Some of these parameters are difficult, if not impossible, to predict. In the end, this type of analysis produces a life-cycle value in present-day dollars, which is then compared to similar investment analyses to select the most reasonable investment. Of course, projected outcomes are always subject to scrutiny.
Where will we be in 20 years? A natural desire for efficiency has resulted in incredible innovations, and they have all been dependent on a mindset that embraces change. It will be interesting to see what the future holds.