# Patent Analysis of the Development of Technologies Applied to the Combustion Process
## 3 Results and Discussion
The results exhibited that oxygen enrichment favors the flame temperature and reduces the hyphae flame length, reduces the total volume of combustion products, and minimizes the carbon monoxide production. Table 2 shows some publications in the scientific literature that address the use of the prospected technologies. \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline
**Title** & **Technology** & **Main Findings and/or Conclusions** & **References** \\ \hline A study on acoustically modulated Bunsen flame and its impingement heat transfer & Acoustic & This study experimentally examined the interaction between an acoustic field and a flame by using a low-power loudspeaker to actuate the oscillation of a Bunsen flame. The results showed a 10\% increase in total heat-transfer rate when the optimum nozzle-to-plate distance was coupled with the most effective forcing frequency of 50 Hz. & [49] \\ \hline \end{tabular}
\end{table} 
Table 2: Articles that focus on the use of acoustic excitation, OEC, or both technologies in the combustion process. Figure 2 shows the main applicants (a) and inventors (b) of the prospected patent documents. The company Siemens AG appears in first place with 11 documents. With operations focused on industry, infrastructure, transportation, and healthcare, in terms of energy, the technology company delivers solutions for the production of oil and gas, power generation, and the transmission and distribution of electrical energy [52]. Compared to the top ten competitors in this set, Siemens AG has 26% of those records. In second place is Alstom Technology, with 10 documents. As a company that is leading societies to a low carbon future, Alstom develops and markets mobility solutions that will provide sustainable foundations for the future of transportation [53]. Asea Brown Boveri, in third place, Alstom is a major candidate for the development of the company. \begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Title** & **Technology** & **Main Findings and/or Conclusions** & **References** \\ \hline \hline \multirow{9}{*}{Soot evolution and flame response to acoustic forcing of laminar non-premixed jet flames at varying amplitudes} & \multirow{9}{*}{Acoustic flames at varying amplitudes} & The authors evaluated the mechanisms that affect soot evolution in time-varying flames of different burner diameters under both steady and forced conditions. The results showed that by increasing the forcing amplitude from low to moderate (from \(\alpha=25\%\) to \(50\%\)), the soot volume was increased by 50\%. However, for the 5.6 mm-diameter burner, a further increase in the forcing amplitude (from \(\alpha=50\%\) to \(75\%\)) did not increase soot production significantly. They concluded that the spatial correlation between the soot field and the temperature profile is influenced by the burner diameter and forcing conditions. & This study demonstrated how flame dynamics change in response to the systematic addition of hydrogen in a low-swirl lean premixed methane–air burner. They evaluated 0\%, 20\%, and 40\% hydrogen by volume in fuel mixtures in a low-swirl burner at several chamber pressures. The results indicated that increasing the pressure and hydrogen concentration led to an increase in the maximum density of the flame surface. & \multirow{9}{*}{OEC} & This study experimentally evaluated the technique of OEC and its interaction with soot formation and thermal radiation in natural-gas-confined flames. The levels of air enrichment applied were 2\% and 4\%, and the results suggested that the use of OEC in natural-gas-confined flames produced an increase in thermal radiation coupled with significant reductions in NOx formation.