OCR Text |
Show and four industrial field site demonstrations were conducted. These successful demonstrations allowed extension of the burner to other industrial uses. In current industrial applications, the primary benefit of the Pyrocore burner is its uniform heat transfer to the heated surface. There are also applications where the low NOx emissions are gaining in importance. The additional benefits of high combustion efficiency, low excess air, uniform turndown, very low noise, and fast response are described in the followIng application histories. INDUSTRIAL APPLICATIONS Some primary applications that demonstrate the attributes of the pyrocore burner are: 1. Firetube boilers 2. Asphalt tank and line heaters 3. Glycol reboilers for natural gas dehydration 4. Heat transfer fluid heaters and vaporizers These applications are discussed below. STEAM AND HOT WATER BOILERS - The one to two percentage point increase in boiler efficiency found in early testing has resulted from the high radiant transfer and low excess air characteristics of the burner. These benefits are consistent wherever the boiler des~gn is compatible with th2 315 kW/m (100,000 Btu/hr-ft ) input rate of the burner, including both firetube and some smaller watertube boilers. This efficiency benefit provides a burner payback within a two year period for boilers of 980 kW (100 hp) and above. Alzeta currently maintains three boiler demonstration sites for continued performance evaluation. The installation of a burner in a 980 kW (100 hp) demonstration boiler is shown in Figure 4. These boilers include both York-Shipley and Cleaver-Brooks models of 392 (40) to 1962 kW (200 hp) in size. With one boiler operating since April, 1983, these applications have accumulated over 10,000 hours and 100,000 cycles in some cases. A low NO market for small boilers now a~pears to be developing in California. The reduced NOx emissions potential has been shown in a 1962 kW (200-hp) Cleaver-Brooks 269 boiler at Community Memorial Hospital in Ventura, California, demonstrated under funding by the Southern California Gas Company. Based on typical NO~ reductions of 60 to 80 percent to aChi~ve emissions below 3.82 x 10-5 Kg/m (20 ppm) in the field demonstration boilers, an initial sale Fig. 4 - Firetube boiler burner installation was made to Rockwell International in Newbury Park, California. Boilers for other emission-sensitive sites are currently being specified. ASPHALT TANK AND LINE HEATERS - Although the firetube boiler is a tube-fired configuration that experiences a nominal efficiency gain from the burner's uniform heat transfer, more significant system benefits are achievable where the process fluid is sensitive to degradation at high temperature. The ability to provide the heat uniformly to the fluid along the length and circumference of the firing tube allowed the Pyrocore burner to find early application to asphalt heating in both storage tanks and line heaters. During the 1984 asphalt heating season, the Imperial Oil Strathcona Refinery in Edmonton, Alberta, Canada was faced with an ongoing problem of fluid coking on the firing tubes in their aS~halt storage tanks (of ~p to 52,000 m (250,000 barrel) capacIty per tank). This situation required the existing flame burners to be fired harder to maintain fluid temperature. As a result, increased |