WET approach

Current designs for venturi scrubbers generally use the vertical downflow of gas through the venturi contactor and incorporate three features (I) a wet-approach or flooded-waU entry sec tion, to avoid dust buildup at a wet-dry pmction (2) an adjustable throat for the venturi (or orifice), to provide for adjustment of the pressure drop and (3) a flooded elbow located below the venturi and ahead of the entrainment separator, to reduce wear by abrasive particles. The venturi throat is sometimes fitted with a refractoiy fining to resist abrasion by dust particles. The entrainment separator is commonly, but not invariably, of the cyclone type. An example of the standard form of venturi scrubber is shown in Fig. 17-48. The wet-approach entiy section has made practical the recirculation of slurries. Various forms of adjustable throats, which may be under manual or automatic control. 

Figure 18. Wetted approach, variable rectangular venturi scrubber.

Current designs for Venturi scrubbers generally use the vertical downflow of gas through the Venturi throat and incorporate three features (1) a wet-approach or flooded-wall entry section to avoid a dust buildup at a wet-dry junction ... 

Virkar and Sharma are the only investigators to have reported systematic measurements ofa, ki,a, and kefl by the chemical method. Their work utilized laboratory-scale vertical venturis, operating with liquid injection either at the throat or ahead of the convergent section. For example, for wetted-approach operation, in the range of gas velocities from 50 to 90... 

C. The detector sensitivity was also found to be inadequate even when increeised by a factor of two beyond its maximum range with an external amplifier. At this sensitivity, the solute peaJc still fronted slightly, but the noise level wets approaching unacceptable levels and no further reduction in sample size (split ratio of 10,000 1) wets possible. Nevertheless, comparison with Hjjjjjj predicted by the Golay equation is... 

Highly cubic ordered cobalt oxides have been successfully synthesized from KlT-6 by an accurately controlled incipient wetness approach. The adding volume of cobalt nitrate and absolute ethanol were determined by the pore volume of KIT-6, and the synthesis procedure is effective and economical. Furthermore, the obtained mesoporous cobalt oxides have better mesostructure comparing with those of former reports. The X-ray diffraction, N2 sorption isotherms, transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS) and Fourier-transform infrared spectroscopy were used to characterize the as-synthesized mesoporous cohalt oxides. 

The all above results show that highly ordered cubic mesoporous cobalt oxides with crystalline walls can be successfully synthesized with the incipient wetness approach by carefully controlling the amount of added precursor solution and the adding rate. First, this approach results in gradual wetting/loading of precursors into the pore channels and the air within the pore channels can be... 

In summary, highly cubic ordered cobalt oxides with crystalline walls have been synthesized by an accurately controlled incipient wetness approach using mesoporous silica as hard template and cobalt nitrate as the precursors. Compared with the previously reported solution impregnation processes, this technique is facile, time-saving and economical. This technique can be used to synthesize ordered mesoporous metal oxides, and we expect that rvith this approach various kinds of mesoporous oxides or other materials can be synthesized, which may benefits their applications in many areas such as in catalysis, sensors, clean energy and electronics. 

In situations where there is no interference from the solvent, impurity and byproduct signals on the polymer signals of interest, the WET approach gives better signal to noise than the PFG NMR approach. This may dictate a choice of... 

The DLVO theory, the principles of polymer-mediated steric interactions, and the wetting approach are aU generic and they should therefore be interconnected. However, the relation between DLVO and steric interactions on the one hand and the interfacial tensions on the other will not be appreciated from the foregoing discussion. In Section 20.5, the apparent disparate approaches are united in a general thermodynamic analysis of particle adhesion. 

---