OCR Text |
Show 11 ® A simplified low N O x method ,the auxiliary-burner flame retaining combustion method adopted For the method of reducing NOx, the auxiliary-burner flame retaining two stage combustion method, same as that for the PAX-R burner was adopted. However, out of the four main air injection outlets, two suck in exhaust and air injection is only by either of the two places on the right or left. As the result, it is thought that effect of thick and thin fuel combustion, same as that of the PAX-R eccentric type may be obtained. Consequently, although the flame length is shorter than of the normal type PAX-R, N O x may be restrained to a similar level. <D Changeover of main gas injection From the characteristics of the self-regenerative burner, consolidating the gas lines in one system is ideal. However, if the gas injection direction is aligned in one direction, short pass of the gas to exhaust tends to occur. Raising of the gas pressure to prevent this tendency poses problems from a practical aspect. Therefore, for this burner, the gas lines were set up in two systems and main air injection side was set so that the gas injected at a slight angle. By this, the gas pressure was suppressed to 3 kPa and less to offer a wide range of use. Also, it became possible to secure a favorable temperature distribution, even with one burner. (alumina balls) Fig. 11 Structure of the PAX-SR burner 3.2 Specifications, performance, Two models of self-generative burners with nominal capacities of 233, and 465 kW were developed. Fig. 12 shows the approximate dimensions of the twin regenerative burner PAX- 50N-R (nominal capacity 581 kW) mentioned above and the present 465 k W specification burner. Volume was reduced to roughly one third of the former. Fig. 13 shows the exhaust heat recovery performance and data relating to NOx. Both display performance which compare favorably with the latest twin type regenerative burner. |