Rotating grating

Pig. 6. Lurgi pressure gasifier A = variable speed drive B = coal distributor C = rotating grate. HP = high pressure. 

In a spectrophotometer, the fixed detector records the wavelength selected by a rotating grating located in the monochromator. This system allows sequential recording of line intensities. 

Fig. 11. Vertical four-section reactor with rotating grates and immobile perforated grate 1 - casing 2 - heat exchanger 3 - redistribution grates 4 - key 5 -shaft 6 - perforated grate for preliminary gas distribution 7 - separation chamber.

A modification of an interferometrically-based system, which was first described by Dohi and Suzuki (24), is known as a selectively-modulated interferometric dispersive spectrometer, this system is a hybrid in that a rotating grating (a dispersive element) is used to limit the number of wavelengths which can interfere at any one time in a modified Michelson interferometer. 

In the producer gas process, coal is fed from the top and moves slowly downwards while humidified air is blown upward through the bed of coal or coke. Ash is removed from the bottom of the gasifier through a rotating grate. The gas product... 

Most colloids are polydisperse in terms of their particle size and charge and thus a single sample exhibits a distribution of mobilities. In principle the above mentioned techniques, in particular optical transients, quasielastic velocimetry in the frequency regime, crossbeam and rotating grating velocimetries, can measure the mobility distribution of a polydisperse colloid. 

The Woodall-Duckham process employs a gasifier (Figure 21.6) which is a vertical cylindrical vessel having a rotating grate in the bottom for ash removal (Howard-Smith and Werner, 1976). There are three functional zones within the reactor (1) a water-jacketed gasification zone, (2) a refractory-lined distillation zone, and (3) a refractory-lined drying zone. 

A reference beam with forward scatter method has been used with a TPD rotating grating preshift and tracking system ( 6) for the 16.4 mm tube. An average volt meter and a correlator HP 3720 with a spectrum analyser were used to interpret the tracker output. Complementary velocity field measurements were carried out in a 44 mm diameter tube. 

The rotating grate at the bottom of the gasifier must maintain smooth removal of the ash (equal decay of the bed) and sufficient distribution of the gasifying... 

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