End-fire

Figure 3-21. Six bask designs used in horizontal-lube fired heaters. Radian section coil is horLmtai. (a) Cabin, (b) Two-cell box. (c) Cabin with dividing bridgewall, (d) End-fired box. e) End-fired box, with side-mounted convection section, (f) Horizontal-tube, single-row, double-h red. [From Chem. Eng., 102-103 (June 19, 1978).]...

Monochromatic laser light of an Ar+ laser (Innova 70 Spectrum Coherent, Inc., Santa Clara, CA) with a wavelength of 647 nm is end-fire coupled into the input fiber connected to the YI chip. The four output divergent beams overlap one another on the front side of a CCD camera (Teli CS-3440 756 x 575 pixels, vvPjxei =11.6... 

Haruna, M. Segawa, Y. Nishihara, H., Nondestructive and simple method of optical wave guide loss measurement with optimization of end fire coupling, Electron. Lett. 1992, 28, 1612 1613... 

Figure 4. Techniques for coupling an external radiation field into optical waveguides (a) prism coupling, (b) grating coupling, and (c) end-fire coupling.

In the end-fire configuration, also known as the slow-wave configuration in antenna theory, the orientation of the E-field of the Poynting vector is irrelevant. To achieve polarization sensitivity, animals use a different chromophore arrangement and orientation, such as rod-shaped microvilli of the arthropod photoreceptor cells. 

Example 13 WSCC Furnace Model Calculations Consider the furnace geometry and combustion stoichiometry described in Example 12. The end-fired furnace is 3 m wide, 5 m tall, and 10 m long. Methane at a firing rate of 2500 kg/h is burned to completion with 20 percent excess air which is preheated to 600°C. The speckled furnace model is to be used. The sink (zone 1)... 

Fig. 3 Schematic illustrating methods of coupling incident light into the waveguide, (a) Simple end firing, (b) Prism coupling, typically requires the presence of index matching fluid, (c) Grating coupling...

Fig. 7 Optical waveguide-coupling methods, (a) end-firing focused beam and end-firing optical fiber (b) prism coupling (c) grating coupling...

Fig. 10 Immobilized AuNPs on the end fire of an optical fiber for transmission and reflection measurements...

Yan et al. [71] have used a hollow photonic crystal fiber bundle to immobilize multifaceted AuNPs of 100-200 nm diameters within the hollow stmcture (Fig. 12). They launched the excitation light at 633 nm for Raman spectroscopy onto the end fire of the photonic crystal fiber with a x50 objective. The same objective lens was used to collect the scattered light for Raman spectroscopy. The sensing material or analyte was rhodamine B immobihzed and dried within the photonic fiber onto the AuNPs. The Raman spectrum showed a clear surface enhancement in the presence of the AuNPs. Nevertheless the authors used a photonic crystal fiber, no band gap... 

Distilling-flask delivery side arms usually made from tubing of about 6 mm diameter, and are easily broken. These flasks are, or should be, made from borosilicate glass and are easily repaired. The remnants of the delivery tube should be removed and a neat hole, about 8 mm diameter, blown in the flask neck. A previously prepared tube, 15 cm long, 8 mm diameter and of medium or heavy walled glass, has one end fire-polished and the other end slightly flared, as shown in Fig. 8.4. The flared end is joined to the flask neck, blown and pulled so that it is inclined downwards, towards the flask bulb. The flask neck, in the region of the delivery tube join, is flame annealed. 

Fig. 5.14. Schematic illustration of a grating coupler device (the outcoupler one is shown, see text for details). The light is incoupling by end-fire. A diffraction grating outcoupled the light onto a photodiode array (detector). The displacement in the position of the outcoupled beam is a quantitative measurement of the interaction that takes place on the grating sensor region.

Conversion to full oxy/fuel also provides an opportunity for production increase. The change in pull rate achieved with an oxy/fuel furnace, in comparison with an air/fuel furnace, varies depending on furnace type. Pull rate increases of up to 60% have been observed for unit melters. Cross-fired regenerative furnaces have seen increases as little as 10%. End-fired regenerative furnaces converted to oxy/fuel increase pull capacity by 20%. Recuperative melters typically achieve a 30% pull rate increase. 

For laser experiments the as fabricated waveguide was used as the laser gain medium without any coupling of external reflectors (mirrors). The experimental set-up used for laser gain experiments is schematically shown in Fig. 2. Optical excitation of the channel waveguide was performed by end-fired coupling a Ti sapphire continuous wave laser operating at 748 nm transition). 

Fig. 1.3. Five-zone steel reheat furnace. Many short zones are better for recovery from effects of mill delays. Using end-fired burners upstream (gas-flow-wise), as shown here, might disrupt flame coverage of side or roof burners. End firing, or longitudinal firing, is most common in one-zone (smaller) furnaces, but can be accomplished with sawtooth roof and bottom zones, as shown. 

Another example of the effect of the problem occurs with the bottom zone of a steel reheat furnace when fired longitudinally counterflow to the load movement, and with the control sensor installed 10 to 20 ft (3-6 m) from the (end-fired) burner wall. At low-firing rates, with the zone temperature set at 2400 F (1316 C), the burner wall may rise to more than 2500 F (1371 C). At that temperature, scale melts and drips to the floor of the bottom zone where it may later solidify as one big piece. At high firing rates, the peak temperature may move beyond the bottom zone T-sensor,... 

Fig. 3.28. Galvanizing tank rebuilt with high-velocity end firing replacing side firing for better tank...

Front-end-fired furnaces should have soak zones to allow equalization independently of the heating zones. Otherwise, (see fig. 4.18) the heating zones must be limited to maximum soak-zone temperatures when the heating zone temperature could be higher for maximum productivity. 

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