Moving grate

In addition to interference filters, NIR manufacturers use holographic gratings (moving and fixed), interferometers, polarization interferometers, diode arrays, acoustic-optic tunable filters, as well as some specialty types. 

A survey of commercial thermal gasification in the United States shows that few gasifiers have been installed since 1984 (115). Most units in use are retrofitted to small boilers, dryers, and kilns. The majority of existing units operate at 0.14 to 1.0 t/h of wood wastes on updraft moving grates. The results of this survey are summarized in Table 36. Assuming all 35 of these units are operated continuously, extremely unlikely, the maximum amount of LHV gas that can be produced is about 0.003 to 0.006 EJ/yr (222—445 td /d). 

The fuel flows at right angles to the air flow. Only a small amount of air is fed at the front of the stoker, to keep the fuel mixture rich, but as the coal moves toward the middle of the furnace, the amount of air is increased, and most of the coal is burned by the time it gets halfway down the length of the grate. Fuel-bed depth varies from 100 to 200 mm (4 to 8 in), depending on the fuel, which can be coke breeze, anthracite, or any noncaking bituminous coal. 

Fan guards of wire grating or hardware cloth are mounted helow the fan to prevent accidental contact with the moving blades and to keep newspapers, leaves, and other light objects from being drawn into the fan. The use of a wire fence around the entire unit is good to keep unauthorized individuals away from all of the equipment how-... 

Coal is fed from a front-feed hopper onto the moving grate through a guillotine door, which controls bed thickness. Nowadays a firebreak system is arranged in the... 

Before each wavelength scan, the grating locates itself by finding the 365 nm triplet of a built-in mercury light source, and then moves sequentially to the wavelengths for the elements to be determined. As an option the instrument... 

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